The phytochemical lindleyin, isolated from Rhei rhizoma, mediates hormonal effects through estrogen receptors

Abstract

Some plant compounds or herb mixtures are popular alternatives to conventional therapies and contain organic compounds that bind to some nuclear receptors, such as the estrogen receptor (ER), to exert various biological effects. We studied the effect of various herbal extracts on ER and ER isoforms. One herbal extract, Rhei rhizoma (rhubarb), acts as an agonist to both ER and ER . The phytochemical lindleyin, a major component of rhubarb, might contribute to this estrogenic activity through ER and ER . 4-Hydroxytamoxifen, an ER antagonist, completely reversed the estrogenic activity of lindleyin.Lindleyin binds to ER in vitro, as demonstrated using a fluorescent polarization assay. The in vivo effect of rhubarb extract was studied using a vitellogenin assay system in the freshwater fish, Japanese medaka (Oryzias latipes). There were marked increases in serum vitellogenin levels in male medaka exposed to rhubarb extract. We conclude that lindleyin, a component of some herbal medicines, is a novel phytoestrogen and might trigger many of the biological responses evoked by the physiological estrogens.

Acteoside and martynoside exhibit estrogenic/antiestrogenic properties

“…For example, a component of ginseng saponin (a ginsenoside), a 4-ethoxymethylphenol, some catechins, and the phytochemical lindleyin may act as agonists/antagonists of estrogens via the ER␣ and ER␤ pathway, depending on their concentration and tissue type [30][31][32][33][34]. In addition, recent studies in our laboratory revealed that plant-derived arylobenzofurans exhibit SERM-like properties [35,36].…”

Phytoestrogens

“…These include isoflavonoids and chalcone (isoliquiritigenin) from licorice root (discussed above). Rhubarb contains the phenylbutanone glucoside lindleyin, which binds to ERα and may be responsible for the biological effects of rhubarb extracts (184). Deoxymiroestrol is a potent phytoestrogen from the "rejuvenating" folk medicine Kwao Keur produced in Thailand from Pueraria mirifica (27).…”

Impacts of Phytoestrogens on Livestock Production: A Review

“…Because endogenous estrogen receptors are widely distributed in the entire reproductive axis (hypothalamus, pituitary, ovary and reproductive tract), it is expected that phytoestrogens can alter reproduction of females on different levels. Many studies have reported that phytoestrogens in legumes may act as antagonists or agonists of endogenous estrogen (Usui et al, 2002). Phytoestrogens generally inhibit endogenous estrogens production, leading to disturbances in the follicular development and lack of the occurrence of estrus (Rosselli et al, 2000).…”