1: J Agric Food Chem. 2001 May;49(5):2472-9. Links
Evaluation of estrogenic activity of plant extracts for the potential treatment of menopausal symptoms.Liu J, Burdette JE, Xu H, Gu C, van Breemen RB, Bhat KP, Booth N, Constantinou AI, Pezzuto JM, Fong HH, Farnsworth NR, Bolton JL.
Department of Medicinal Chemistry and Pharmacognosy, UIC/NIH Center for Botanical Dietary Supplements Research, College of Pharmacy, M/C 781, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois 60612, USA.
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) activity and up-regulation of progesterone receptor (PR) mRNA. Chasteberry also stimulated PR expression, but no induction of AP activity was observed. In S30 breast cancer cells, pS2 (presenelin-2), another estrogen-inducible gene, was up-regulated in the presence of red clover, hops, and chasteberry. Interestingly, extracts of Asian ginseng (Panax ginseng C.A. Meyer) and North American ginseng (Panax quinquefolius L.) induced pS2 mRNA expression in S30 cells, but no significant ER binding affinity, AP induction, or PR expression was noted in Ishikawa cells. Dong quai [Angelica sinensis (Oliv.) Diels] and licorice (Glycyrrhiza glabra L.) showed only weak ER binding and PR and pS2 mRNA induction. Black cohosh [Cimicifuga racemosa (L.) Nutt.] showed no activity in any of the above in vitro assays. Bioassay-guided isolation utilizing ER competitive binding as a monitor and screening using ultrafiltration LC-MS revealed that genistein was the most active component of red clover. Consistent with this observation, genistein was found to be the most effective of four red clover isoflavones tested in the above in vitro assays. Therefore, estrogenic components of plant extracts can be identified using assays for estrogenic activity along with screening and identification of the active components using ultrafiltration LC-MS. These data suggest a potential use for some dietary supplements, ingested by human beings, in the treatment of menopausal symptoms.
1: Pak J Biol Sci. 2007 Jul 15;10(14):2300-7.Links
The effects of Vitex agnus castus extract and its interaction with dopaminergic system on LH and testosterone in male mice.Nasri S, Oryan S, Rohani AH, Amin GR.
Department of Biology, Parand Branch, Azad University, Tehran, Iran.
The purpose of this study was to evaluate the probable effects of Vitex agnus castus (Vac.) on the male reproductive physiology. It is a well known fact that LH secretion from the anterior pituitary of mammals is controlled by many neurotransmiters such as dopamine. In this experiment, we have studied the effect of Vac. extract on the LH and testosterone hormones and its interaction with the dopaminergic system on male mice. In order to evaluate these effects, we used the hydroalcoholic Vac. extract (for extraction we used percolation technique) injection with the following doses: 65, 165, 265, 365 and 465 mg kg-', bromocriptine as a dopamine receptor agonist (5, 10, 20 mg kg(-1)) and haloperidol as a dopamine receptor antagonist (1, 1.5, 2, 2.5, 3 mg kg(-1)). To study the interaction between Vac. extract and dopaminergic system, we injected the optimum doses of Vac. with bromocriptine or haloperidol at the same time. Intraperitoneal injections were applied in all experiments, once a day for 30 days. The control group remained intact and the sham group received vehicle. After the last injection, we collected the animal blood serums for hormonal assays. LH and testosterone were measured by Radio Immuno Assay (RIA). LH and testosterone, showed significant decrease in bromocriptine group and haloperidol increased these hormones. Vac. extract decreased significantly the LH and testosterone levels. The coadministration of Vac. extract and bromocriptine decreased LH and testosterone. Coadministration of Vac. extract and haloperidol decreased LH and testosterone levels. These results suggest: dopamine regulates the gonadotroph-leydig cells axis. It appears that Vac. exertes effects through dopaminergic system and other pathways. The findings of this study show we can use Vac. extract for pathological cases of increasing LH and testosterone.
). The removal of this protective effect as weel as the increase in "free" estrogen from the reduction in SHBG can explain some of the propensity for forming gyno with these compounds. With nandrolone, trenbolone, and other 19-norsteroids, there is also the added production of 5-alpha reduced metabolites that are weak androgens (there is some evidence that tren is metabolized in this fashion) which upstes the androgen to estrogen rati and further contributes to the ability to produce gyno.
