phytoestrogens

[Guest guest]

Can't find anything on Rehmannia and estrogen, but here is something

showing how other herbs can bind to estrogen receptors and upregulate a

gene that causes breast cancer. Note that dang gui does not have this

effect, but ginseng does upregulate the cancer gene.

 

J Agric Food Chem 2001 May;49(5):2472-9

 

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.

 

 

Chinese Herbs

 

 

" Great spirits have always been violently opposed by mediocre minds " --

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