| antimicrobial screening of essential oils and extracts of some humulus lupulus l. cultivars. | the essential oils as well as solvent extracts of 11 hop cultivars, 1 hop variety and a wild type of hop were screened for their antimicrobial activities using the agar overlay technique. the oils were isolated from the cones of the various hop plants by hydrodistillation, the extracts were obtained by soaking the hop cones in chloroform. the oils and the extracts showed activity against the gram-positive bacteria (bacillus subtilis and staphylococcus aureus) and the fungus (trichophyton mentagr ... | 1992 | 1475174 |
| factors affecting antibacterial activity of hop compounds and their derivatives. | the antibacterial effect of weak acids derived from the hop plant (humulus lupulus l.) increased with decreasing ph. analysis of the minimum inhibitory concentration of such compounds against lactobacillus brevis ifo 3960 over ph 4-7 suggests that undissociated molecules were mainly responsible for inhibition of bacterial growth. the antibacterial activity of trans-isohumulone was ca 20 times greater than that of humulone, 11 times greater than that of colupulone and nine times greater than that ... | 1992 | 1517174 |
| glycaemic effects of traditional european plant treatments for diabetes. studies in normal and streptozotocin diabetic mice. | twelve plants used for the traditional treatment of diabetes mellitus in northern europe were studied using normal and streptozotocin diabetic mice to evaluate effects on glucose homeostasis. the plants were administered in the diet (6.25% by weight) and/or as decoctions or infusions in place of drinking water, to coincide with the traditional method of preparation. treatment for 28 days with preparations of burdock (arctium lappa), cashew (anacardium occidentale), dandelion (taraxacum officinal ... | 1989 | 2743711 |
| [pharmacodynamic study of the lupulus' (humulus lupulus l.) tranquilizing action]. | | 1974 | 4423848 |
| [spasmolytic action of hop (humulus lupulus, cannabinacees)]. | | 1969 | 5377603 |
| humulon, a bitter in the hop, inhibits tumor promotion by 12-o-tetradecanoylphorbol-13-acetate in two-stage carcinogenesis in mouse skin. | humulon, one of the bitters in the hop, was isolated from the female flowers of humulus lupulus. this component has inhibitory activity against 12-o-tetradecanoylphorbol-13-acetate (tpa)-induced inflammation. at 1 mg/mouse, humulon inhibited markedly the tumor-promoting effect of tpa (1 microgram/mouse) on skin tumor formation following initiation with 7,12-dimethylbenz[a]anthracene (50 micrograms/mouse). furthermore, humulon inhibited arachidonic acid-induced inflammatory ear edema in mice. | 1995 | 7854777 |
| screening of apple mosaic virus in hop cultivars in the czech republic by reverse transcription-polymerase chain reaction. | thirteen cultivars of hop (humulus lupulus l.) were tested by reverse transcription-polymerase chain reaction (rt-pcr) for the presence of apple mosaic virus (apmv). the virus was detected in various amounts in all tested cultivars. control hop clones derived from tissue cultures, treated by thermotherapy and maintained in greenhouse were virus-free. the procedure for sample preparation and rt-pcr of apmv is described in detail. | 1997 | 9219641 |
| xanthohumols, diacylglycerol acyltransferase inhibitors, from humulus lupulus. | a methanol extract of hops of humulus lupulus (l.) showed inhibitory activity against rat liver diacylglycerol acyltransferase (dgat). from dgat inhibitory activity-guided fractionation, two chalcones were isolated. one was identified as xanthohumol and the other was found to be a new product designated xanthohumol b. the structure of xanthohumol b was shown to be 6-[3,4-dihydro-3,5-dihydroxy-7-methoxy-2,2-dimethyl-2h-benzo[b]pyrano ]- 3-(4-hydroxyphynyl)-2-propen-l-one by spectroscopic studies ... | 1997 | 9366096 |
| identification of a potent phytoestrogen in hops (humulus lupulus l.) and beer. | the female flowers of the hop plant are used as a preservative and as a flavoring agent in beer. however, a recurring suggestion has been that hops have a powerful estrogenic activity and that beer may also be estrogenic. in this study, sensitive and specific in vitro bioassays for estrogens were used for an activity-guided fractionation of hops via selective solvent extraction and appropriate hplc separation. we have identified a potent phytoestrogen in hops, 8-prenylnaringenin, which has an ac ... | 1999 | 10372741 |
| antiproliferative and cytotoxic effects of prenylated flavonoids from hops (humulus lupulus) in human cancer cell lines. | six flavonoids [xanthohumol (xn), 2',4',6',4-tetrahydroxy-3'-prenylchalcone (tp); 2',4',6',4-tetrahydroxy-3'-geranylchalcone (tg); dehydrocycloxanthohumol (dx); dehydrocycloxanthohumol hydrate (dh); and isoxanthohumol (ix)] from hops (humulus lupulus) were tested for their antiproliferative activity in human breast cancer (mcf-7), colon cancer (ht-29) and ovarian cancer (a-2780) cells in vitro. xn, dx and ix caused a dose-dependent (0.1 to 100 microm) decrease in growth of all cancer cells. afte ... | 1999 | 10418944 |
| in vitro inhibition of human p450 enzymes by prenylated flavonoids from hops, humulus lupulus. | 1. several unique flavonoid compounds have recently been isolated from hops, humulus lupulus, and their presence has been detected in beer. their chemical structures are similar to other plant-derived compounds, many present in the human diet, that have been shown to have cancer chemopreventive properties due, in part, to inhibition of cytochrome p450 enzymes that activate carcinogens. additionally, preliminary studies have shown these flavonoids (at 100 microm) to be inhibitory of p450-mediated ... | 2000 | 10752639 |
| biotransformation of monoterpene alcohols by saccharomyces cerevisiae, torulaspora delbrueckii and kluyveromyces lactis. | monoterpenoids are important flavour compounds produced by many plant species, including grapes (vitis vinifera) and hops (humulus lupulus). biotransformation reactions involving monoterpenoids have been characterized in filamentous fungi, but few examples have been observed in yeasts. as monoterpenoids are in contact with yeasts during beer and wine production, biotransformation reactions may occur during the fermentation of these beverages. this paper describes the biotransformation of monoter ... | 2000 | 10790686 |
| fate of xanthohumol and related prenylflavonoids from hops to beer. | the fate of three prenylated flavonoids of the chalcone type, xanthohumol, desmethylxanthohumol, and 3'-geranylchalconaringenin, was monitored with lc/ms-ms from hops (humulus lupulus l.) to beer in two brewing trials. the three prenylchalcones were largely converted into their isomeric flavanones, isoxanthohumol, prenylnaringenins, and geranylnaringenins, respectively, in the boiling wort. losses of prenylflavonoids were due to incomplete extraction from the hops into the wort (13-25%), adsorpt ... | 1999 | 10794646 |
| host-plant diversity of the european corn borer ostrinia nubilalis: what value for sustainable transgenic insecticidal bt maize? | the strategies proposed for delaying the development of resistance to the bacillus thuringiensis toxins produced by transgenic maize require high levels of gene flow between individuals feeding on transgenic and refuge plants. the european corn borer ostrinia nubilalis (hübner) may be found on several host plants, which may act as natural refuges. the genetic variability of samples collected on sagebrush (artemisia sp.), hop (humulus lupulus l.) and maize (zea mays l.) was studied by comparing t ... | 2000 | 10902683 |
| the endocrine activities of 8-prenylnaringenin and related hop (humulus lupulus l.) flavonoids. | the female flowers of the hop plant have long been used as a preservative and a flavoring agent in beer, but they are now being included in some herbal preparations for women for "breast enhancement." this study investigated the relative estrogenic, androgenic and progestogenic activities of the known phytoestrogen, 8-prenylnaringenin, and structurally related hop flavonoids. 6-prenylnaringenin, 6,8-diprenylnaringenin and 8-geranylnaringenin exhibited some estrogenicity, but their potency was le ... | 2000 | 11134162 |
| in vitro biotransformation of xanthohumol, a flavonoid from hops (humulus lupulus), by rat liver microsomes. | xanthohumol (xn) is the major prenylated flavonoid of the female inflorescences (cones) of the hop plant (humulus lupulus). it is also a constituent of beer, the major dietary source of prenylated flavonoids. recent studies have suggested that xn may have potential cancer-chemopreventive activity, but little is known about its metabolism. we investigated the biotransformation of xn by rat liver microsomes. three major polar metabolites were produced by liver microsomes from either untreated rats ... | 2001 | 11181488 |
| are there any links between hop japanese pollen and other weed pollens or food allergens on skin prick tests? | recent investigations suggest that the importance of hop japanese pollen, which has been known as one of the major causative weed pollens, is increasing in this country. there have been few data dealing with the allergenic relationship between hop j pollen and other food or inhalant allergens. among 2909 patients who visited the allergy clinic of ajou university hospital, suwon, korea, 471 patients sensitized to hop j, mugwort, or ragweed pollens on skin-prick test were enrolled. positive rates ... | 2001 | 11227917 |
| evaluation of estrogenic activity of plant extracts for the potential treatment of menopausal symptoms. | eight botanical preparations that are commonly used for the treatment of menopausal symptoms were tested for estrogenic activity. methanol extracts of red clover (trifolium pratense l.), chasteberry (vitex agnus-castus l.), and hops (humulus lupulus l.) showed significant competitive binding to estrogen receptors alpha (er alpha) and beta (er beta). with cultured ishikawa (endometrial) cells, red clover and hops exhibited estrogenic activity as indicated by induction of alkaline phosphatase (ap) ... | 2001 | 11368622 |
| attractive and defensive functions of the ultraviolet pigments of a flower (hypericum calycinum). | the flower of hypericum calycinum, which appears uniformly yellow to humans, bears a uv pattern, presumably visible to insects. two categories of pigments, flavonoids and dearomatized isoprenylated phloroglucinols (dips), are responsible for the uv demarcations of this flower. flavonoids had been shown previously to function as floral uv pigments, but dips had not been demonstrated to serve in that capacity. we found the dips to be present in high concentration in the anthers and ovarian wall of ... | 2001 | 11707571 |
| chemotaxonomic features associated with flavonoids of cannabinoid-free cannabis (cannabis sativa subsp. sativa l.) in relation to hops (humulus lupulus l.). | the major flavonoids present in the leaves and flowers of the cannabinoid-free cannabis (cannabis sativa subsp. sativa l.) cultivars felina and futura are orientin (1), vitexin (2), luteolin-7-o-beta-d-glucuronide (3), and apigenin-7-o-beta-d-glucuronide (4), while prenylated flavonoids, to which the potent estrogenicity of hops (humilus lupulus l.) is associated, are absent. the different composition of flavonoids has chemotaxonomic value. | 2002 | 11942684 |
| development of a bipartite method for fusarium identification based on cellobiohydrolase-c: caps and western blot analysis. | the identification of 12 fusarium strains isolated from diseased hops (humulus lupulus, l.) was achieved by a strategy based on cellobiohydrolase-c: cleaved amplified polymorphic sequence analysis targeting the gene and the use of an antibody directed against a peptide of the fusarium graminearum enzyme. this strategy is shown to be rapid and reliable for all the fusarium of our collection: f. avenaceum, f. graminearum, f. sambucinum, f. sporotrichioides, f. tricinctum and f. venenatum. | 2002 | 12167545 |
| inhibitors of nitric oxide production from hops (humulus lupulus l.). | nitric oxide (no) plays an important role in many inflammatory responses and is also involved in carcinogenesis. in the present study, we investigated the inhibitory effect of extracts from humulus lupulus l. on both the production of no and the expression of inducible no synthase (inos) in mouse macrophage raw 264.7 cells. the production of no was induced by a combination of lipopolysaccharide (lps) and ifn-gamma, and determined by griess assay. the expression of inos was detected by western bl ... | 2003 | 12520174 |
| a preliminary rapd-pcr analysis of cimicifuga species and other botanicals used for women's health. | traditional taxonomic methods of botanical identification that rely primarily on morphological observations cannot be used efficiently when only powdered plant materials are available. thus, our objectives were to determine if we could apply a molecular approach to: a) produce unique dna profiles that are characteristic of the species, and b) determine if the geographical area or time of collection influences these dna profiles. towards this end, random amplified polymorphic dna (rapd) analyses ... | 2002 | 12587700 |
| surveys of microfungi in a former industrial area in duisburg-nord. | one hundred and forty microfungi (ascomycetes and deuteromycetes) were collected in the "landschaftspark duisburg-nord" located in north rhine-westphalia. new hosts for rarely found fungi are recorded for the first time. new for germany are massaria inquinans (tode) de not. and nitschkia grevillei (rhem) nannf. on acer pseudoplatanus l., pirottaea nigrostriata graddon on artemisia vulgaris l., ceratopycnis clematidis höhn. on clematis vitalba l., dasyscyphus aff. humuli (w. phillips) dennis on h ... | 2002 | 12701427 |
| regeneration and agrobacterium-mediated transformation of hop (humulus lupulus l.). | an efficient procedure for direct organogenesis and regeneration of hop (humulus lupulus l.) was established. for the first time agrobacterium-mediated genetic transformation of hop (cv. "tettnanger") was achieved. shoot internodes from in vitro cultures were identified as the most suitable type of explant for regeneration. using this type of explant, a shoot-inducing medium was developed that supported direct organogenesis of approximately 50% of the explants. plantlets were successfully rooted ... | 2003 | 12898178 |
| inhibition of peroxynitrite-mediated ldl oxidation by prenylated flavonoids: the alpha,beta-unsaturated keto functionality of 2'-hydroxychalcones as a novel antioxidant pharmacophore. | prenylated 2'-hydroxychalcones and flavanones from the inflorescences of the female hop plant (humulus lupulus) were shown to inhibit peroxynitrite-mediated oxidation of low-density lipoproteins (ldl) at low micromolar concentrations. ldl oxidation was induced by the peroxynitrite generator, 3-morpholinosydnonimine (sin-1), and measured by the formation of conjugated dienes and thiobarbituric reactive substances. human intake of prenylated chalcones and flavanones is mainly through beer, which c ... | 2003 | 14565769 |
| mechanisms of cancer chemoprevention by hop bitter acids (beer aroma) through induction of apoptosis mediated by fas and caspase cascades. | the bitter acids of hops (humulus lupulus l.) mainly consist of alpha-acids, beta-acids, and their oxidation products that contribute the unique aroma of the beer beverage. hop bitter acids displayed a strong growth inhibitory effect against human leukemia hl-60 cells, with an estimated ic(50) value of 8.67 microg/ml, but were less effective against human histolytic lymphoma u937 cells. induction of apoptosis was confirmed in hl-60 cells by dna fragmentation and the appearance of a sub-g1 dna pe ... | 2004 | 14709013 |
| metabolism of 8-prenylnaringenin, a potent phytoestrogen from hops (humulus lupulus), by human liver microsomes. | the female flowers of hops are used throughout the world as a flavoring agent for beer. recently, there has been increasing interest in the potential estrogenic properties of hop extracts. among the possible estrogenic compounds in hops, 8-prenylnaringenin is perhaps most significant due to its high in vitro potency exceeding that of other known phytoestrogens. since data regarding the pharmacokinetic properties of this compound are lacking, we investigated the in vitro metabolism of 8-prenylnar ... | 2004 | 14744951 |
| phytoestrogens in botanical dietary supplements: implications for cancer. | phytoestrogens are plant constituents that possess either estrogenic or antiestrogenic activity. although their activities are weak as compared with human endogenous estrogens, the consumption of phytoestrogens may have clinically significant consequences. a number of botanicals, or the compounds contained therein, have been identified as putative estrogenic agents, but consensus in the biomedical community has been hampered by conflicting data from various in vitro and in vivo models of estroge ... | 2003 | 15035899 |
| bioindicator plants for ambient ozone in central and eastern europe. | sixteen species of native detector plants for ambient ozone have been identified for use in central and eastern europe. they include the forbs alchemilla sp., astrantia major, centuarea nigra, centauria scabiosa, impatiens parviflora, lapsana communis, rumex acetosa and senecio subalpinus; the shrubs corylus avellana, cornus sanguinea and sambucus racemosa; the trees alnus incana, pinus cembra and sorbus aucuparia; and the vines humulus lupulus and parthenocissus quinquefolia. sensitivity to ozo ... | 2004 | 15046838 |
| qualitative and quantitative variation among volatile profiles induced by tetranychus urticae feeding on plants from various families. | many plant species are known to emit herbivore-induced volatiles in response to herbivory. the spider mite tetranychus urticae koch is a generalist that can feed on several hundreds of host plant species. volatiles emitted by t. urticae-infested plants of 11 species were compared: soybean (glycine max), golden chain (laburnum anagyroides), black locust (robinia pseudo-acacia), cowpea (vigna unguiculata), tobacco (nicotiana tabacum), eggplant (solanum melalonga), thorn apple (datura stramonium), ... | 2004 | 15074658 |
| application of a yeast method for dna extraction associated with database interrogations for the characterization of various filamentous fungi from diseased hop. | filamentous fungi were collected from diseased hop (humulus lupulus; l.) and dna was prepared from 19 isolates. the critical step of cell lysis was carried out using zymolyase for fungal cell wall digestion. dna was successfully prepared for all isolates and allowed ribosomal dna region amplifications by pcr. the amplicons were sequenced and sequences were compared with nucleotides databases. these analyses allowed identification of each fungus and gave a precise view of the ecosystem. seven dif ... | 2004 | 15104139 |
| host-plant specialization in pheromone strains of the european corn borer ostrinia nubilalis in france. | european corn borer (ecb) feeding on maize (zea mais), mugwort (artemisia vulgaris), and hop (humulus lupulus) are genetically different in france and referred to as host-plant races. here, we investigated sex pheromone composition as a possible trait linked to the host plant. ecb host races were sampled from 13 different sites in france. gc-ms analysis of female pheromone showed that 175 out of 176 maize females belonged to the z type with one hybrid. in contrast, mugwort and hop females belong ... | 2004 | 15112728 |
| cloning and over-expression of a cdna encoding a polyketide synthase from cannabis sativa. | a polyketide synthase has been suggested to play an important role in cannabinoid biosynthesis in cannabis sativa l. this enzyme catalyzes the biosynthesis of olivetolic acid, one of the precursors for cannabinoid biosynthesis. using a reverse transcriptase-polymerase chain reaction (rt-pcr) based on the dna homology of chalcone synthase (ec 2.3.1.156) and valerophenone synthase (ec 2.3.1.156) of hop (humulus lupulus), a cdna encoding a polyketide synthase in c. sativa was identified. the coding ... | 2004 | 15120113 |
| exposure of hop growers to bioaerosols. | air sampling was performed during picking and sorting of hop (humulus lupulus) cones on 19 hop farms located in eastern poland. the concentration and composition of airborne microflora and the concentration of airborne dust and endotoxin were determined. additionally, 7 samples of settled hop dust were collected and examined for the presence of microorganisms and endotoxin. total concentrations of airborne microorganisms were within a range of 2.08-129.58 x 10(3) cfu/m(3). gram-positive bacteria ... | 2004 | 15236510 |
| health effects of inhalation exposure to organic dust in hops farmers. | medical examinations were performed in a group of 23 hops farmers exposed to organic dust from hop (humulus lupulus). the examinations took place in individual farms during harvesting, sorting and transporting of hop cones. as a reference group, 50 urban dwellers not exposed to organic dust were examined. there were conducted physical examinations, interviews concerning the occurrence of respiratory disorders and work-related symptoms, lung function tests, determination of cytokines concentratio ... | 2003 | 15315032 |
| molecular cloning, expression, and characterization of adenylate isopentenyltransferase from hop (humulus lupulus l.). | a cdna encoding adenylate isopentenyltransferase (aipt) was cloned and sequenced from cones of hop (humulus lupulus l.) by rt-pcr using oligonucleotide primers based on the conserved sequences of arabidopsis thaliana aipt isozymes (atipt1, atipt3, atipt4, atipt5, atipt6, atipt7 and atipt8). a full-length cdna contained a 990-bp open reading frame encoding a molecular mass of 36,603 da protein with 329 amino acids. further, dna sequencing of genomic dna revealed absence of introns in the frame. o ... | 2004 | 15381407 |
| the antimycobacterial components of hops (humulus lupulus) and their dereplication. | bioassay-guided fractionation of a hexane extract of strobile hops (humulus lupulus) was undertaken to isolate and characterize the antimycobacterial constituents using the fast-growing mycobacterial species mycobacterium fortuitum. activity was associated with a low polarity fraction and 1h nmr spectra indicated the presence of a fatty acid mixture with unsaturated components. gc-ms of the derivatives indicated the presence of palmitic, stearic and oleic acids with small quantities of lignoceri ... | 2004 | 15478197 |
| xanthohumol, a novel anti-hiv-1 agent purified from hops humulus lupulus. | xanthohumol, prenylchacone flavonoid, is a natural product with multi-biofunctions purified from hops humulus lupulus. its anti-hiv-1 activity was tested in the present study. results showed that xanthohumol inhibited hiv-1 induced cytopathic effects, the production of viral p24 antigen and reverse transcriptase in c8166 lymphocytes at non-cytotoxic concentration. the ec50 values were 0.82, 1.28 and 0.50 microg/ml, respectively. the therapeutic index (ti) was about 10.8. xanthohumol also inhibit ... | 2004 | 15550272 |
| genetic isolation between two sympatric host plant races of the european corn borer, ostrinia nubilalis hubner. ii: assortative mating and host-plant preferences for oviposition. | the european corn borer, ostrinia nubilalis hubner, colonized maize (zea mays l.) after its introduction into europe about 500 years ago and is now considered one of the main pests of this crop. in northern france, two sympatric host races have been described: one feeding on maize and the other on mugwort (artemisia vulgaris l.) and hop (humulus lupulus l.). in a previous study, we showed that mating between the two races may be impeded by differences in the timing of moth emergence and in the c ... | 2005 | 15562285 |
| prenylflavonoids and phloroglucinol derivatives from hops (humulus lupulus). | the ethyl acetate soluble fraction of hops (humulus lupulus) showed potent inhibitory activity on the production of nitric oxide (no) induced by a combination of lps and ifn-gamma. four known prenylflavonoids (1-4) and a new prenylflavonoid (5), hulupinic acid (6), lupulone (7), and its six new derivatives (8-13) were isolated from the active fraction. the structures were determined on the basis of physiochemical properties and spectroscopic analysis. their inhibitory activities on the productio ... | 2005 | 15679315 |
| effect of humulus lupulus on gastric secretion in a rat pylorus-ligated model. | in this study, we investigated the pharmacological effect of humulus lupulus (hops) on gastric juice volume and acidity using a rat pylorus-ligated model. in an intraorally administered experiment, hops clearly increased gastric juice volume without affecting acidity. on the other hand, hops had no influence on gastric juice volume when it was intragastrically administered. a cholinergic agonist, carbachol, increased gastric juice volume without affecting acidity, whereas histamine increased gas ... | 2005 | 15684498 |
| metabolism of xanthohumol and isoxanthohumol, prenylated flavonoids from hops (humulus lupulus l.), by human liver microsomes. | the female flowers of hops (humulus lupulus l.) used to flavor beer contain the prenylated flavonoids xanthohumol (xn) and isoxanthohumol (ix). ix is moderately estrogenic in vitro and xn has pharmacological properties that might make it useful as a cancer chemopreventive agent. the metabolism of these dietary flavonoids was investigated in vitro using human liver microsomes. hydroxylation of a prenyl methyl group was the primary route of oxidative metabolism forming either cis or trans hydroxyl ... | 2005 | 15712367 |
| a safety study of oral tangeretin and xanthohumol administration to laboratory mice. | the detection of molecular targets for flavonoids in cell signalling has opened new perspectives for their application in medicine. both tangeretin, a citrus methoxyflavone, and xanthohumol, the main prenylated chalcone present in hops (humulus lupulus l.), act on the mitogen-activated protein kinase pathway and await further investigation for administration in vivo. | 2005 | 15796161 |
| in vitro antiplasmodial activity of prenylated chalcone derivatives of hops (humulus lupulus) and their interaction with haemin. | there is an urgent need to discover new antimalarials, due to the spread of chloroquine resistance and the limited number of available drugs. chalcones are one of the classes of natural products that are known to possess antiplasmodial properties. therefore, the in vitro antiplasmodial activity of the main hop chalcone xanthohumol and seven derivatives was evaluated. in addition, the influence of the compounds on glutathione (gsh)-dependent haemin degradation was analysed to determine its contri ... | 2005 | 15824094 |
| antiinvasive effect of xanthohumol, a prenylated chalcone present in hops (humulus lupulus l.) and beer. | the female inflorescences of the hop plant (humulus lupulus l.) are essential during brewing to add taste and flavor to beer and to stabilize beer foam. xanthohumol, the main prenylated chalcone in hops, was investigated for its antiinvasive activity on human breast cancer cell lines (mcf-7 and t47-d) in vitro. xanthohumol was able to inhibit the invasion of mcf-7/6 cells at 5 microm in the chick heart invasion assay and of t47-d cells in the collagen invasion assay. xanthohumol inhibited growth ... | 2005 | 15986430 |
| xanthohumol induces apoptosis in cultured 40-16 human colon cancer cells by activation of the death receptor- and mitochondrial pathway. | xanthohumol (xn) is one of the major prenylflavonoids found in hop cones (humulus lupulus l.). in this study, we investigated the cell growth inhibitory potential of xn on cultured human colon cancer cells. cell proliferation was measured by sulforhodamine b staining. poly(adp-ribose)polymerase (parp) cleavage, activation of caspases-3, -7, -8, and -9, and bcl-2 family protein expression were detected by western blot analyses. xn significantly reduced proliferation of the hct 116-derived colon c ... | 2005 | 15995977 |
| new insight in the neuropharmacological activity of humulus lupulus l. | the purpose of the present study was to investigate the effects of humulus lupulus co2 extract and its fraction containing alpha-acids on the central nervous system of rats. both tested substances were able to prolong pentobarbital sleeping time, without affecting the latency to the loss of the righting reflex. this effect was dose-dependent, starting from a minimal dose of 10 mg/kg. neither the extract nor its alpha-acid fraction affected the locomotor activity in the open field test or exerted ... | 2005 | 16046089 |
| activation of proestrogens from hops (humulus lupulus l.) by intestinal microbiota; conversion of isoxanthohumol into 8-prenylnaringenin. | hop, an essential ingredient in most beers, contains a number of prenylflavonoids, among which 8-prenylnaringenin (8-pn) would be the most potent phytoestrogen currently known. although a number of health effects are attributed to these compounds, only a few reports are available about the bioavailability of prenylflavonoids and the transformation potency of the intestinal microbial community. to test these transformations, four fecal samples were incubated with xanthohumol, isoxanthohumol (ix), ... | 2005 | 16076107 |
| xanthohumol stimulates iodide uptake in rat thyroid-derived frtl-5 cells. | sodium-iodide-symporter (nis), an integral plasma membrane glycoprotein, mediates the sodium-dependent active uptake of iodide (i(-)) into the thyroid gland, which is a fundamental step in thyroid hormone synthesis. in this work, we analyzed the influence of xanthohumol (xn), a prenylated chalcone from hops (humulus lupulus l.), on the i(-) uptake in a cell culture model of normal, nontransformed rat thyrocytes (frtl-5). acute treatment with nanomolar concentrations of xn does not influence i(-) ... | 2005 | 16092068 |
| broad spectrum anti-infective potential of xanthohumol from hop (humulus lupulus l.) in comparison with activities of other hop constituents and xanthohumol metabolites. | this review summarizes the capacity of xanthohumol (xn) in comparison with additional hop constituents and metabolites to act as an antiinfective agent against microorganisms including bacteria, viruses, fungi and malarial protozoa. xn was shown to inhibit the gram-positive bacteria staphylococcus aureus and streptococcus mutans. antiviral activity was demonstrated against bovine viral diarrhea virus, cytomegalovirus, herpes simplex virus type 1 and 2 and human immunodeficiency virus 1. inhibiti ... | 2005 | 16092071 |
| xanthohumol isolated from humulus lupulus inhibits menadione-induced dna damage through induction of quinone reductase. | the female parts of hops (humulus lupulus l.) show estrogenic effects as well as cancer chemopreventive potential. we analyzed the chemopreventive mechanism of hops by studying its antioxidative activities and its effect on the detoxification of a potentially toxic quinone (menadione). the detoxification enzyme quinone reductase [(nad(p)h:quinone oxidoreductase, qr] protects against quinone-induced toxicity and has been used as a marker in cancer chemoprevention studies. although the hop extract ... | 2005 | 16097803 |
| expression of allene oxide cyclase and accumulation of jasmonates during organogenic nodule formation from hop (humulus lupulus var. nugget) internodes. | a crucial step in the biosynthesis of jasmonic acid (ja) is the formation of its stereoisomeric precursor, cis-(+)-12-oxophytodienoic acid (opda), which is catalyzed by allene oxide cyclase (aoc, ec 5.3.99.6). a cdna of aoc was isolated from humulus lupulus var. nugget. the orf of 765 bp encodes a 255 amino acid protein, which carries a putative chloroplast targeting sequence. the recombinant protein without its putative chloroplast target sequence showed significant aoc activity. previously we ... | 2005 | 16100229 |
| xanthohumol, the chalcone from beer hops (humulus lupulus l.), is the ligand for farnesoid x receptor and ameliorates lipid and glucose metabolism in kk-a(y) mice. | we have examined the modulating action of xanthohumol (xn) on the farnesoid x receptor (fxr) in vitro and in vivo. in the transient transfection assay, xn dose-dependently increased the bsep promoter-driven luciferase activity. xn-fed kk-a(y) mice exhibited lowered levels of plasma glucose, plasma, and hepatic triglyceride. they also showed decreased amounts of water intake, lowered weights of white adipose tissue, and exhibited increased levels of plasma adiponectin, indicating that xn attenuat ... | 2005 | 16140264 |
| screening method for the discovery of potential cancer chemoprevention agents based on mass spectrometric detection of alkylated keap1. | natural products are important sources of drugs such as cancer chemopreventive agents, but most assays for the discovery of compounds in natural product extracts are low throughput and provide little information about lead compounds in these complex mixtures. the induction of enzymes such as quinone reductase, glucuronyl transferases, glutathione s-transferases, and sulfotransferases can protect cells against the toxic and neoplastic effects of carcinogens. an increase in the concentration of nr ... | 2005 | 16194107 |
| diversity of the exoproteome of fusarium graminearum grown on plant cell wall. | the exoproteome of the fungus fusarium graminearum grown on glucose and on hop (humulus lupulus, l.) cell wall has been investigated. the culture medium was found to contain a higher quantity of proteins and the proteins are more diverse when the fungus is grown on cell wall. using both 1d and 2d electrophoresis followed by mass spectrometry analysis and protein identification based on similarity searches, 84 unique proteins were identified in the cell wall-grown fungal exoproteome. many are put ... | 2005 | 16283313 |
| the pharmacognosy of humulus lupulus l. (hops) with an emphasis on estrogenic properties. | as the population ages, there is an ever-increasing need for therapeutic agents that can be used safely and efficaciously to manage symptoms related to postmenopausal estrogen deficiency. endogenous estrogens, e.g., 17beta-estradiol, of exogenous mammalian origin, e.g., horses, have long been used to manage such symptoms. there are more than 20 different classes of phytochemicals that have demonstrated affinity for human estrogen receptors in vitro. some studies on exogenous estrogenic substance ... | 2006 | 16360942 |
| selective inhibition of cox-2 by a standardized co2 extract of humulus lupulus in vitro and its activity in a mouse model of zymosan-induced arthritis. | a standardized co(2) extract from humulus lupulus l. (hop extract) was investigated for its selective cox-1/2 inhibitory properties. an in vitro model of inflammation using lipopolysaccharide (lps)-stimulated human peripheral blood mononuclear cells (pbmc) was used as a model to investigate the effect of hop extract on pge(2) production. cox-1/2 selective inhibition by the hop extract was investigated in a cox-1 whole blood assay (wba) and a cox-2 wba. to evaluate the in vivo activity of hop ext ... | 2006 | 16534727 |
| effects of beer and hop on ionotropic gamma-aminobutyric acid receptors. | beer induced the response of the ionotropic gamma-aminobutyric acid receptors (gaba(a) receptors) expressed in xenopus oocytes, indicating the presence of gamma-aminobutyric acid (gaba)-like activity. furthermore, the pentane extract of the beer, hop (humulus lupulus l.) oil, and myrcenol potentiated the gaba(a) receptor response elicited by gaba. the gaba(a) receptor responses were also potentiated by the addition of aliphatic esters, most of which are reported to be present in beer flavor. ali ... | 2006 | 16569037 |
| effects of hop extracts on nasal rubbing and sneezing in balb/c mice. | the effects of hop extracts (humulus lupulus l.) on histamine release from rat peritoneal mast cells and human basophilic ku812 cells were studied. hop water extract (hwe) and xad-4 50% methanol fraction of hwe (mfh) inhibited histamine release from rat mast cells induced by compound 48/80 at concentrations of 100 and 10 mug/ml, respectively. almost the same findings were observed with a23187-induced histamine release from ku812 cells. next, we studied the effects of hop extracts on antigen-indu ... | 2006 | 16595900 |
| identification of human hepatic cytochrome p450 enzymes involved in the metabolism of 8-prenylnaringenin and isoxanthohumol from hops (humulus lupulus l.). | the female flowers of hops (humulus lupulus l.) are used in the brewing of beer and are under investigation for use in dietary supplements for the management of menopausal symptoms in women. hop extracts contain the weakly estrogenic compound isoxanthohumol (ix), proestrogenic xanthohumol, and the potent estrogen 8-prenylnaringenin (8pn). because ix can be metabolized in the human liver to form 8pn, the specific cytochrome p450 (p450) enzymes responsible for this o-demethylation reaction were id ... | 2006 | 16611861 |
| influence of xanthohumol on the binding behavior of gabaa receptors and their lateral mobility at hippocampal neurons. | the influence of the xanthohumol from humulus lupulus l. on the binding of muscimol-alexa fluor 532 (mu-alexa), a fluorescently labeled gabaa receptor agonist, was studied by fluorescence correlation spectroscopy. an incubation of hippocampal neurons with 75 nm of xanthohumol increased the specific mu-alexa binding by approximately 17%, which was selectively found in gabaa receptor mu-alexa complexes with hindered lateral mobility [d(bound2) = (0.11 +/- 0.03) microm2/s] as described with midazol ... | 2006 | 16636971 |
| anti-proliferative properties of prenylated flavonoids from hops (humulus lupulus l.) in human prostate cancer cell lines. | chalcones xanthohumol (x) and desmethylxanthohumol (dmx), present in hops (humulus lupulus l.), and the corresponding flavanones isoxanthohumol (ix, from x), 8-prenylnaringenin (8-pn, from dmx), and 6-prenylnaringenin (6-pn, from dmx), have been examined in vitro for their anti-proliferative activity on human prostate cancer cells pc-3 and du145. x proved to be the most active compound in inhibiting the growth of the cell lines with ic50 values of 12.3+/-1.1 microm for du145 and 13.2+/-1.1 micro ... | 2006 | 16678392 |
| in vitro studies of intestinal permeability and hepatic and intestinal metabolism of 8-prenylnaringenin, a potent phytoestrogen from hops (humulus lupulus l.). | the absorption potential and metabolism of 8-prenylnaringenin (8-pn) from hops (humulus lupulus l.) were investigated. 8-pn is a potent estrogen with the potential to be used for the relief of menopausal symptoms in women. | 2006 | 16715376 |
| the prenylflavonoid isoxanthohumol from hops (humulus lupulus l.) is activated into the potent phytoestrogen 8-prenylnaringenin in vitro and in the human intestine. | hops, an essential beer ingredient, are a source of prenylflavonoids, including 8-prenylnaringenin (8-pn), one of the most potent phytoestrogens. because 8-pn concentrations in beers are generally low, its health effects after moderate beer consumption were considered negligible. however, human intestinal microbiota may activate up to 4 mg/l isoxanthohumol (ix) in beer into 8-pn. depending on interindividual differences in the intestinal transformation potential, this conversion could easily inc ... | 2006 | 16772450 |
| behavioural response of colorado potato beetle (leptinotarsa decemlineata) larvae to selected plant extracts. | potato leaves were treated with 2, 20 or 200 g kg(-1) solutions of extracts of five plant species collected in turkey, and then exposed to larvae of colorado potato beetle, leptinotarsa decemlineata (say). during the first 24 h of exposure, leaf consumption was not affected by 2 g kg(-1) extracts, whereas significantly more leaf tissue remained on leaves treated with 20 g kg(-1) extracts of arctium lappa l., bifora radians m bieb, humulus lupulus l. or xanthium strumarium l. than on untreated co ... | 2006 | 16886174 |
| evidence that the beta-acids fraction of hops reduces central gabaergic neurotransmission. | humulus lupulus (hops) is traditionally used as a tranquilizing herbal remedy. here, we investigated the in vivo and in vitro effect of hop beta-acids on central nervous system function. oral administration of beta-acids (5-10mg/kg) in rats produced an increased exploratory activity in the open field, a reduction in the pentobarbital hypnotic activity and a worsening of picrotoxin-induced seizures. when dosed at 10mg/kg, beta-acids increased, in the elevated plus maze, open arm entries reducing ... | 2007 | 16920300 |
| sequence analysis of a "true" chalcone synthase (chs_h1) oligofamily from hop (humulus lupulus l.) and pap1 activation of chs_h1 in heterologous systems. | screening of a cdna library of the hop cv. osvald's 72 and genomic cloning were used to isolate members of an oligofamily of chs_h1 genes that codetermine the biosynthesis of prenylated chalcones known to be valuable medicinal compounds present in hop (humulus lupulus l.). chs_h1 oligofamily members showed more than 99% and 98% identity on nucleotide and amino acid levels, respectively, and retained all conserved amino acids that form the catalytic center characteristic for "true" chalcone synth ... | 2006 | 17002429 |
| the hop phytoestrogen, 8-prenylnaringenin, reverses the ovariectomy-induced rise in skin temperature in an animal model of menopausal hot flushes. | the mechanisms underlying menopausal hot flushes are poorly understood, although it is generally assumed they result from disturbances of thermoregulatory centres in the hypothalamus. 8-prenylnaringenin (8-pn) has been identified as a potent phytoestrogen in hops (humulus lupulus) and there are claims that hop-containing preparations can reduce hot flushes. we have investigated the site of action of 8-pn in a rat model of menopausal hot flushes, in which the tail skin temperature (tst) is increa ... | 2006 | 17088409 |
| a tlc bioautographic assay for the detection of nitrofurantoin resistance reversal compound. | a simple tlc bioautographic method was developed for detection of antibiotic resistance reversal agents. in this study, the retention factor values of the components of some essential oils not previously shown to have any antibacterial activity were evaluated on nitrofurantoin supplemented agar media. the active component of artemisia annua, artemisia dracunculus and eucalyptus globulus essential oils was piperitone which increased the antibacterial activity of nitrofurantoin against enterobacte ... | 2007 | 17140862 |
| flavonoid glycosides extracted from hop (humulus lupulus l.) as inhibitors of chemical mediator release from human basophilic ku812 cells. | the antiallergic properties of hop water extract (hwe) were studied by evaluating histamine release from human basophilic ku812 cells induced by calcium ionophore a23187. hwe significantly inhibited histamine release, but boiling water extract and chloroform-methanol extract did not show any inhibitory effect on it. a 50% methanol-eluted fraction separated from hwe by xad-4 column chromatography (mfh) had a strong inhibitory effect as compared with hwe. quercetin glycosides and kaempherol glycos ... | 2006 | 17151464 |
| humulone inhibits phorbol ester-induced cox-2 expression in mouse skin by blocking activation of nf-kappab and ap-1: ikappab kinase and c-jun-n-terminal kinase as respective potential upstream targets. | humulone, a bitter acid derived from hop (humulus lupulus l.), possesses antioxidative, anti-inflammatory and other biologically active activities. although humulone has been reported to inhibit chemically induced mouse skin tumor promotion, the underlying mechanisms are yet to be elucidated. since an inappropriate over-expression of cyclooxygenase-2 (cox-2) is implicated in carcinogenesis, we investigated effects of humulone on cox-2 expression in mouse skin stimulated with the tumor promoter 1 ... | 2007 | 17372274 |
| hypothermic effects of hops are antagonized with the competitive melatonin receptor antagonist luzindole in mice. | hops (humulus lupulus, cannabinaceae) has been used in traditional european medicine as a mild sedative for the treatment of anxiety, nervousness, and insomnia. however, there has been little information available about the underlying sleep inducing mechanism of hops. we have investigated the effects of a hops extract on the rectal body temperature in mice. hops extract (250 mg kg(-1)) significantly decreased body temperature in male bl6/c57j mice (deltat -0.75 +/- 0.07 degrees c) 2 h after oral ... | 2007 | 17430638 |
| chemopreventive effects of lupulone, a hop {beta}-acid, on human colon cancer-derived metastatic sw620 cells and in a rat model of colon carcinogenesis. | the bitter acids of hops (humulus lupulus l.) mainly consist of humulones or alpha-acids and lupulones or beta-acids. we aimed to evaluate the antiproliferative mechanisms of lupulones on a human metastatic colon carcinoma-derived cell line (sw620 cells) and to assess their chemopreventive effects in a model of colon carcinogenesis. sw620 cell growth was inhibited by 70% after a 48 h exposure to lupulones (40 microg/ml). lupulones up-regulated the expression of fas receptor (fas) and fas ligand ... | 2007 | 17434926 |
| binding of the hop (humulus lupulus l.) chalcone xanthohumol to cytosolic proteins in caco-2 intestinal epithelial cells. | used in the brewing of beer, hops (humulus lupulus l.) contain the prenylated chalcone xanthohumol, which is under investigation as a cancer chemoprevention agent and as a precursor for the estrogenic flavanones isoxanthohumol and 8-prenylnaringenin. the uptake, transport and accumulation of xanthohumol were studied using the human intestinal epithelial cell line caco-2 to help understand the poor bioavailability of this chalcone. studies were carried out using caco-2 cell monolayers 18-21 days ... | 2007 | 17579893 |
| protective effects of xanthohumol against the genotoxicity of benzo(a)pyrene (bap), 2-amino-3-methylimidazo[4,5-f]quinoline (iq) and tert-butyl hydroperoxide (t-booh) in hepg2 human hepatoma cells. | xanthohumol is the major prenylated flavonoid present in the hop plant humulus lupulus l. (cannabinaceae) and a common ingredient of beer. recently, xanthohumol has gained considerable interest due to its potential cancer chemo-preventive effect. the aim of this study was to reveal the possible anti-genotoxic activity of xanthohumol in metabolically competent human hepatoma hepg2 cells, by use of the comet assay. xanthohumol by itself was neither cytotoxic nor genotoxic to the cells at concentra ... | 2007 | 17590382 |
| ability of prenylflavanones present in hops to induce apoptosis in a human burkitt lymphoma cell line. | the identification of effective cancer preventive compounds from hops has become an important issue in public health-related research. we compared the antiproliferative and apoptosis-inducing effects of side chain variants of prenylflavanones, e. g., 8-prenylnaringenin (7) and 8-geranylnaringenin (10), which have been identified in hops (humulus lupulus), and their synthetic variations 8-furanmethylnaringenin (8) and 8-cinnamylnaringenin (9). these were accessible by a mitsunobu reaction and cla ... | 2007 | 17715491 |
| isobavachalcone, a chalcone constituent of angelica keiskei, induces apoptosis in neuroblastoma. | six chalcones from angelica keiskei koidzumi (ashitaba in japanese) and two chalcones from humulus lupulus l. (hop) were examined for their cytotoxicity in two human neuroblastoma cell lines (imr-32 and nb-39) and normal cells (primary culture of rat cerebellar granule cells) by [3-(4,5)-dimethyl-2-thiazolyl]-2,5-diphenyl-2h-tetrazolium bromide (mtt) assay. all chalcones exhibited cytotoxicity against neuroblastoma cells, and two of them (isobavachalcone and xanthoangelol h) had no effect on nor ... | 2007 | 17917255 |
| effects of aqueous hop (humulus lupulus l.) extract on vascular reactivity in rats: mechanisms and influence of gender and hormonal status. | phytoestrogens, naturally occurring plant compounds having oestrogenic and/or anti-oestrogenic activity, are present in many human foodstuffs including hop. moderate intakes of isoflavonoid phytoestrogens have been associated with a reduction in cardiovascular diseases incidence. so, it is possible that hop (humulus lupulus l.) might similarly contribute to the reported health-beneficial effects of moderate beer consumption. thus, the purpose of this study was to investigate in vitro effects of ... | 2008 | 17951040 |
| antimutagenicity of hops (humulus lupulus l.): bioassay-directed fractionation and isolation of xanthohumol. | bioassay-directed fractionation with a salmonella/microsomal assay against the food borne mutagen 2-amino-3-methylimidazo[4,5-f]quinoline (iq) was used to identify antimutagenic components of hops. hops pellets extracted with diethylether showed antimutagenic activity against mutations induced by iq. fractionation of the diethylether extract (de) by column chromatography, followed by semi-preparative hplc yielded two fractions (e4b and e4d) with strong antimutagenic activity against iq induced m ... | 2008 | 17959367 |
| antigenotoxic effect of xanthohumol in rat liver slices. | xanthohumol (xn), the principal prenylated flavonoid in the hop plant, humulus lupulus l., is suggested to have cancer chemo-preventive activities. its mechanisms of protection have been proposed to be inhibition of metabolic activation, induction of detoxifying enzymes and antioxidant activity. our previous study showed that xn efficiently protected human hepatoma hepg2 cells against the genotoxic effects of two pro-carcinogens (2-amino-3-methylimidazo[4,5-f]quinoline (iq) and benzo(a)pyrene (b ... | 2008 | 17981005 |
| effects of isometric strength training followed by no exercise and humulus lupulus l-enriched diet on bone metabolism in old female rats. | we investigated in female rats the effects on bone metabolism of a prolonged no-training period, subsequent to an isometric exercise program, performed during young adulthood and those of a long-term consumption of humulus lupulus l-enriched diet (genistein 1.92 and daidzein 1.24 mg/kg diet) combined or not with isometric training. forty-eight rats (4 weeks old) were randomly divided into 4 groups: trained (c-tr) or nontrained rats (c-ntr) fed with control diet and trained (h-tr) or nontrained r ... | 2007 | 17998020 |
| effects of traditionally used anxiolytic botanicals on enzymes of the gamma-aminobutyric acid (gaba) system. | in canada, the use of botanical natural health products (nhps) for anxiety disorders is on the rise, and a critical evaluation of their safety and efficacy is required. the purpose of this study was to determine whether commercially available botanicals directly affect the primary brain enzymes responsible for gamma-aminobutyric acid (gaba) metabolism. anxiolytic plants may interact with either glutamic acid decarboxylase (gad) or gaba transaminase (gaba-t) and ultimately influence brain gaba le ... | 2007 | 18066140 |
| gene expression in fusarium graminearum grown on plant cell wall. | fusarium graminearum is a phytopathogenic filamentous fungus attacking a wide range of plants including humulus lupulus (hop). transcriptional analysis of f. graminearum grown on minimal media containing hop cell wall or glucose as the sole carbon source was performed by applying a highly stringent method combining microarrays and a subtracted cdna library. in addition to genes coding for various cell wall degrading enzymes (cwde), several metabolic pathways were induced in response to the plant ... | 2008 | 18249015 |
| antimicrobial activity of lupulone against clostridium perfringens in the chicken intestinal tract jejunum and caecum. | owing to the spread of antibiotic resistance among human infectious agents, there is a need to research antibiotic alternatives for use in animal agricultural systems. antibiotic-free broiler chicken production systems are known to suffer from frequent outbreaks of necrotic enteritis due in part to pathogenic type a clostridium perfringens. hop (humulus lupulus) bitter acids are known to possess potent antimicrobial activity. lupulone was evaluated for in vivo antimicrobial activity to inhibit c ... | 2008 | 18276602 |
| enhanced effects of xanthohumol plus honokiol on apoptosis in 3t3-l1 adipocytes. | to study the effects of xanthohumol (xn), a flavonoid found in hops (humulus lupulus) and honokiol (hk), a lignan isolated from magnolia officinalis, alone and in combination, on apoptotic signaling in 3t3-l1 adipocytes. | 2008 | 18369342 |
| new prenylchalcones from the hops of humulus lupulus. | two new prenylchalcones, xanthohumol c and d, together with two known prenylchalcone derivatives, xanthohumol (1) and 5''-(2''-hydroxyisopropyl)-dihydrofurano-[2'',3''-b]-4,4'-dihydroxy-6'-methoxy-chalcone (4) were isolated and identified from the hops of humulus lupulus l. the structures of xanhohumol c and d were elucidated as 5''-hydroxy-6'',6''-dimethyl-dihydropyrano-[2'',3''-b]-4,4'-dihydroxy-6'-methoxy-chalcone (2) and 5''-hydroxy-6'',6''-dimethyl-dihydropyrano-[2'',3''-b]-4',6'-dimethoxy- ... | 2008 | 18470798 |
| dna sequence and expression variation of hop (humulus lupulus) valerophenone synthase (vps), a key gene in bitter acid biosynthesis. | the hop plant (humulus lupulus) is a source of many secondary metabolites, with bitter acids essential in the beer brewing industry and others having potential applications for human health. this study investigated variation in dna sequence and gene expression of valerophenone synthase (vps), a key gene in the bitter acid biosynthesis pathway of hop. | 2008 | 18519445 |
| eubacterium limosum activates isoxanthohumol from hops (humulus lupulus l.) into the potent phytoestrogen 8-prenylnaringenin in vitro and in rat intestine. | recently, it was shown that the exposure to the potent hop phytoestrogen 8-prenylnaringenin (8-pn) depends on intestinal bacterial activation of isoxanthohumol (ix), but this occurs in only one-third of tested individuals. as the butyrate-producing eubacterium limosum can produce 8-pn from ix, a probiotic strategy was applied to investigate whether 8-pn production could be increased in low 8-pn producers, thus balancing phytoestrogen exposure. using fecal samples from high (hop +) and low (hop - ... | 2008 | 18567753 |
| effect of xanthohumol on melanogenesis in b16 melanoma cells. | xanthohumol (xh), the principal prenylflavonoid of the hop plant (humulus lupulus l.), dose-dependently inhibited isobutylmethylxanthine (ibmx)-induced melanogenesis in b16 melanoma cells, with little cytotoxicity at the effective concentrations. decreased melanin content was accompanied by reduced tyrosinase enzyme activity, protein and mrna expression. the levels of tyrosinase-related protein 1 and 2 mrnas were decreased by xh. xh also inhibited alpha-melanocyte stimulating hormone- or forskol ... | 2008 | 18587269 |
| in vivo estrogenic comparisons of trifolium pratense (red clover) humulus lupulus (hops), and the pure compounds isoxanthohumol and 8-prenylnaringenin. | the lack of a safe and reliable alternative to hormone therapy (ht) for treating menopausal symptoms underscores the need for alternative therapies. objective: the purpose of this study was to assess the in vivo estrogenic effects of the botanical dietary supplements trifolium pratense (red clover) and humulus lupulus (hops), and two compounds obtained from h. lupulus, isoxanthohumol and 8-prenylnaringenin (8-pn) using the ovariectomized uterotrophic adult rat model. a h. lupulus extract and a 3 ... | 2008 | 18619951 |
| terpene biosynthesis in glandular trichomes of hop. | hop (humulus lupulus l. cannabaceae) is an economically important crop for the brewing industry, where it is used to impart flavor and aroma to beer, and has also drawn attention in recent years due to its potential pharmaceutical applications. essential oils (mono- and sesquiterpenes), bitter acids (prenylated polyketides), and prenylflavonoids are the primary phytochemical components that account for these traits, and all accumulate at high concentrations in glandular trichomes of hop cones. t ... | 2008 | 18775972 |
| inhibitory effects of xanthohumol from hops (humulus lupulus l.) on human hepatocellular carcinoma cell lines. | xanthohumol is one of the main flavonoids in hop extracts and in beer. very few investigations of xanthohumol have studied hepatocellular carcinoma. in this study, the inhibitory effects of xanthohumol on human hepatocellular carcinoma cell lines were investigated. the ic(50) values of xanthohumol for two hepatocellular carcinoma cell lines and one normal hepatocyte cell line were 108, 166 and 211 microm, respectively. normal murine hepatocyte cell line had more resistance to xanthohumol than he ... | 2008 | 18814205 |
| in vitro evaluation of antibacterial, anticollagenase, and antioxidant activities of hop components (humulus lupulus) addressing acne vulgaris. | seven naturally derived components from hop plant (humulus lupulus l.) extracts were tested for evaluation of biological activities affecting acne vulgaris. five strains, propionibacterium acnes, staphylococcus epidermidis, staphylococcus aureus, kocuria rhizophila and, staphylococcus pyogenes, were selected as the main acne-causing bacteria. hop extracts xanthohumol and the lupulones showed strong inhibitory activities against all of the strains. although hydrogenated derivatives did not show t ... | 2009 | 19201179 |
| effects of powdery mildew fungicide programs on twospotted spider mite (acari: tetranychidae), hop aphid (hemiptera: aphididae), and their natural enemies in hop yards. | twospotted spider mite, tetranychus urticae koch (acari: tetranychidae), and hop aphid, phorodon humuli (schrank) (hemiptera: aphididae), are the most important arthropod pests of hop (humulus lupulus l.) in the northern hemisphere. a potential barrier for greater adoption of conservation biological control strategies for spider mites and hop aphid is the extensive use of fungicides for management of hop powdery mildew, podosphaera macularis (wallr.:fr.) u. braun & s. takamatsu. field studies co ... | 2009 | 19253646 |
| hop proanthocyanidins induce apoptosis, protein carbonylation, and cytoskeleton disorganization in human colorectal adenocarcinoma cells via reactive oxygen species. | proanthocyanidins (pcs) have been shown to suppress the growth of diverse human cancer cells and are considered as promising additions to the arsenal of chemopreventive phytochemicals. an oligomeric mixture of pcs from hops (humulus lupulus) significantly decreased cell viability of human colon cancer ht-29 cells in a dose-dependent manner. hop pcs, at 50 or 100 microg/ml, exhibited apoptosis-inducing properties as shown by the increase in caspase-3 activity. increased levels of intracellular re ... | 2009 | 19271284 |
| responses of plasma acetate metabolism to hop (humulus lupulus l.) in sheep. | an isotope dilution method using [1-(13)c]sodium (na) acetate was conducted to determine the effect of feeding hop (humulus lupulus l.) residues on plasma acetate metabolism in six adult crossbred sheep. the sheep were fed 63 g/kg bw(0.75)/d of either mixed hay (mh-diet) of orchardgrass (dactylis glomerata l.) and reed canarygrass (phalaris arundinacea l.) at a 60:40 ratio or mh-diet and hop-residues (hop-diet) at 85:15 ratio with a crossover design for each of 3 week period. the isotope dilutio ... | 2009 | 19365576 |
| the antimicrobial effects of hops (humulus lupulus l.) on ruminal hyper ammonia-producing bacteria. | to assess the antimicrobial effects of hops (humulus lupulus l.) on hyper ammonia producing-bacteria (hab), which catabolize amino acids and peptides in the bovine rumen. | 2009 | 19413813 |
| hop (humulus lupulus)-derived bitter acids as multipotent bioactive compounds. | hop acids, a family of bitter compounds derived from the hop plant (humulus lupulus), have been reported to exert a wide range of effects, both in vitro and in vivo. they exhibit potential anticancer activity by inhibiting cell proliferation and angiogenesis, by inducing apoptosis, and by increasing the expression of cytochrome p450 detoxification enzymes. furthermore, hop bitter acids are effective against inflammatory and metabolic disorders, which makes them challenging candidates for the tre ... | 2009 | 19476340 |
| heterodimeric geranyl(geranyl)diphosphate synthase from hop (humulus lupulus) and the evolution of monoterpene biosynthesis. | myrcene, which accounts for 30-50% of the essential oil in hop (humulus lupulus l.) trichomes, derives from geranyl diphosphate (gpp), the common precursor of monoterpenes. full-length sequences of heterodimeric gpp synthase small subunit (gpps.ssu, belonging to the ssu i subfamily) and large subunit (lsu) cdnas were mined from a hop trichome cdna library. the ssu was inactive, whereas the lsu produced gpp, farnesyl diphosphate, and geranylgeranyl diphosphate (ggpp) from dimethylallyl diphosphat ... | 2009 | 19482937 |