Investigation of the estrogenic activity of Pueraria candollei variety mirifica extract on rats

Background: Pueraria candollei variety mirifica (PM) has been widely used as ingredient in many rejuvenating products. In this study, we aimed to assess the estrogenic activity of PM extract grown in Vietnam.Methods: Estrogenic activity of PM extract was estimated on immature female rats by using uterotrophic method to measure the weight of the reproductive organs. Estrogenic activity of PM extract also was investigated in mature female ovariectomized rats by evaluating the vaginal cells growth, reproductive organs weight, serum estradiol concentration.Results: Our results showed that PM extract at doses of 100 mg/kg, 200 mg/kg had increased the reproductive organs weight in immature rats and female ovariectomized rats. In addition, PM extract had increased the serum estradiol concentration and the vaginal cells growth by increasing the percentage of keratinocytes in female ovariectomized rats.Conclusions: Our results showed that PM extract has strong estrogenic activity in rats.

Differential binding with ERá and ERâ of the phytoestrogen-rich plant Pueraria mirifica

Variations in the estrogenic activity of the phytoestrogen-rich plant, Pueraria mirifica, were determined with yeast estrogen screen (YES) consisting of human estrogen receptors (hER) hERá and hERâ and human transcriptional intermediary factor 2 (hTIF2) or human steroid receptor coactivator 1 (hSRC1), respectively, together with the â-galactosidase expression cassette. Relative estrogenic potency was expressed by determining the â-galactosidase activity (EC50) of the tuber extracts in relation to 17â-estradiol. Twenty-four and 22 of the plant tuber ethanolic extracts interacted with hERá and hERâ, respectively, with a higher relative estrogenic potency with hERâ than with hERá. Antiestrogenic activity of the plant extracts was also determined by incubation of plant extracts with 17â-estradiol prior to YES assay. The plant extracts tested exhibited antiestrogenic activity. Both the estrogenic and the antiestrogenic activity of the tuber extracts were metabolically activated with the rat liver S9-fraction prior to the assay indicating the positive influence of liver enzymes. Correlation analysis between estrogenic potency and the five major isoflavonoid contents within the previously HPLC-analyzed tuberous samples namely puerarin, daidzin, genistin, daidzein, and genistein revealed a negative result.

The mutagenic and antimutagenic effects of the traditional phytoestrogen-rich herbs, Pueraria mirifica and Pueraria lobata

Pueraria mirifica is a Thai phytoestrogen-rich herb traditionally used for the treatment of menopausal symptoms. Pueraria lobata is also a phytoestrogen-rich herb traditionally used in Japan, Korea and China for the treatment of hypertension and alcoholism. We evaluated the mutagenic and antimutagenic activity of the two plant extracts using the Ames test preincubation method plus or minus the rat liver mixture S9 for metabolic activation using Salmonella typhimurium strains TA98 and TA100 as indicator strains. The cytotoxicity of the two extracts to the two S. typhimurium indicators was evaluated before the mutagenic and antimutagenic tests. Both extracts at a final concentration of 2.5, 5, 10, or 20 mg/plate exhibited only mild cytotoxic effects. The plant extracts at the concentrations of 2.5, 5 and 10 mg/plate in the presence and absence of the S9 mixture were negative in the mutagenic Ames test. In contrast, both extracts were positive in the antimutagenic Ames test towards either one or both of the tested mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and benzo(a)pyrene. The absence of mutagenic and the presence of anti-mutagenic activities of the two plant extracts were confirmed in rec-assays and further supported by a micronucleus test where both plant extracts at doses up to 300 mg/kg body weight (equivalent to 16 g/kg body weight plant tuberous powder) failed to exhibit significant micronucleus formation in rats. The tests confirmed the non-mutagenic but reasonably antimutagenic activities of the two plant extracts, supporting their current use as safe dietary supplements and cosmetics.

Clinical trial of the phytoestrogen-rich herb, pueraria mirifica as a crude drug in the treatment of symptoms in menopausal women.

The clinical trial to evaluate the estrogenic effects of the crude drug derived from dry powder of a phytoestrogen-rich Thai herb Pueraria mirifica (White Kwao Krua) in five female volunteers with menopausal symptoms showed that the crude drug clearly improved the signs and symptoms related to menopause such as, hot flushes, frustration, sleep disorder, skin dryness, high blood cholesterol, oligomenorrhoea and amenorrhoea, with no change in the blood cells, liver and kidney functions, as well as other physiological status after four months of treatment. In four volunteers, treatments were continued to complete the one-year test period with half the dose and was found to maintain their satisfied menopausal relief status. The crude drug dosage was administered at 200 mg daily for three weeks a month during the first four months of treatment and 200 mg every other day for 20 days per month for the remaining of eight months. These doses were effective and safe as phytoestrogen treatment of menopausal symptoms.