| Produced by plants, phytoestrogens are chemicals that have the ability to mimic biological effects of the female hormone estrogen. Due to the possible health effects of their consumption, these compounds have received a great deal of attention lately. Epidemiological studies supported by laboratory findings suggest that phytoestrogens may be linked to low incidence of hormone related cancers as well as menopausal symptoms, osteoporosis and cardiovascular diseases. On the other hand, the adverse effects on fertility and reproductive development observed in wild, domestic and experimental animals have raised a concern about possibility of such effects in humans.; 8-prenylnaringenin, a potent phytoestrogen present in hops and beer, exhibits an estrogenic activity greater than that of any other known phytoestrogen. In the present study, a simple, rapid and reproducible method has been developed for determination of 8-prenylnaringenin in hops and hop products. Linearity of the method was shown to be excellent, with R2 > 0.999. Recoveries were between 95.0% (0.25 μg/mL) and 105.9% (1.0 μg/mL).; The method was used for quantitation of 8-prenylnaringenin in 24 American hop varieties. Some of the varieties were in different product forms, and harvested in two different years. The levels were shown to vary among hop varieties and hop products. Dried cones and hop pellets contained approximately the same amount of 8-prenylnaringenin, while carbon dioxide extracts of hops did not contain any. Hops spent during the production of carbon dioxide extracts, on the other hand, were shown to be rich source of 8-prenylnaringenin and could be used for its isolation. The concentration of 8-prenylnaringenin in hops varied with harvest year. Estrogenic activity of hops was assessed by growth based and β-galactosidase assays. The activity varied among hop varieties in the same fashion as the concentration of 8-prenylnaringenin. In the growth based assay, 8-prenylnaringenin showed the same affinity for α and β estrogen receptors. |
