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Abstract Extracts from black cohosh (Cimicifuga racemosa, CR) exert an anti-proliferative action in human breast cancer cell cultures, which has been attributed to an anti-estrogenic effect. However, CR constituents do [...]

Abstract Belamcanda chinensis (BC) belongs to the family of iridaceae and the isoflavone tectorigenin has been isolated from the rhizome of this plant. Whether this isoflavone has estrogenic, possibly selective [...]

Summary Extracts of the fruits of chaste tree (Vitex agnus castus = AC) are widely used to treat premenstrual symptoms. Double-blind placebo-controlled studies indicate that one of the most common [...]

Isoflavones have been shown to exert antiproliferative effects on cancer cells by steroid receptor signaling. In this study, we demonstrate the potential of plant constituents extracted from Belamcanda chinensis as anticancer drugs, which regulate the aberrant expression of genes relevant in proliferation, invasion, immortalization and apoptosis. LNCaP cells were treated with B.chinensis extract, tectorigenin or other isoflavones and mRNA expression was quantified by using real time RT-PCR. In addition, ELISA, TRAP assays and western blots were used to measure protein expression or activity. Male nude mice (n=18) were injected subcutaneously with LNCaP cells and were fed with extracts from B.chinensis, and tumor development was monitored versus a control animal group (n=18). Tectorigenin and several other phytochemicals downregulated PDEF, PSA and IGF-1 receptor mRNA expression in vitro. Furthermore, PSA secretion and IGF-1 receptor protein expression were diminished, and hTERT mRNA expression and telomerase activity decreased after tectorigenin treatments. However, TIMP-3 mRNA was upregulated on tectorigenin treatment. Growth of subcutaneous tumors in nude mice was delayed and diminished in animals fed with extracts from B.chinensis. The downregulation of PDEF, PSA, hTERT and IGF-1 receptor gene expression by tectorigenin demonstrates the antiproliferative potential of these agents. The upregulation of TIMP-3 gene expression indicates a pro-apoptotic function of the drug and a reduction of the invasiveness of tumors. The animal experiments demonstrate that B.chinensis markedly inhibited the development of tumors in vivo. Thus, these compounds may be useful for the prevention or treatment of human prostate cancer.

Extracts from black cohosh (Cimicifuga racemosa, CR) exert an anti-proliferative action in human breast cancer cell cultures, which has been attributed to an anti-estrogenic effect. However, CR constituents do not bind to either of the known estrogen receptors. Thus, the anti-tumor effect of CR me be mediated by mechanisms not involving these receptors. Polycyclic aromatic hydrocarbons are toxic environmental pollutants, which indirectly act as anti-estrogens by activating the aryl hydrocarbon receptor (AhR). The AhR is widely expressed in mammalian tissues and tumors. A recent screening study demonstrated activation of the AhR by a variety of herbal extracts, among others, CR. Since activation of the AhR causes inhibition of growth of prostate cancer cells, we addressed the question, whether CR may not only inhibit growth of breast cancer--but also of prostate cancer cells. In the AhR ligand assay, the CR extract BNO 1055 reduced tracer binding to 71% of the control demonstrating interaction of constituents of this extract with the receptor. Under basal as well as under estradiol- and dihydrotestosterone stimulated conditions, the CR extract dose dependently inhibited proliferation of LNCaP cells. A significant reduction of cell growth was observed at a concentration as low as 50 ng/ml. Thus, it is demonstrated for the first time that CR compounds potently inhibit the growth of human prostate cancer cells in vitro. This anti-proliferative effect may be mediated via the AhR.

Belamcanda chinensis (BC) belongs to the family of iridaceae and the isoflavone tectorigenin has been isolated from the rhizome of this plant. Whether this isoflavone has estrogenic, possibly selective estrogen receptor modulator activities and if so, whether they are mediated via the estrogen receptor alpha or beta is unknown at present. Therefore, we performed binding studies with recombinant human ERalpha and ERbeta to show that tectorigenin binds to both receptor subtypes. In ERalpha-expressing MCF7 and ERbeta-expressing MDA-MB231 reporter gene transfected cells tectorigenin causes transactivation. When given intravenously to ovariectomized (ovx) rats, it inhibits pulsatile pituitary LH secretion. In postmenopausal women estrogen-unopposed LH pulses correlate with hot flushes. Therefore, suppression of pulsatile LH secretion may be beneficial in women suffering from hot flushes. Upon chronic application to ovx rats a BC extract containing 5% Belamcanda at a daily dose of 33 mg or 130 mg of the extract had no effect on uterine weight or on estrogen-regulated uterine gene expression while estrogenic effects in the bone, on bone mineral density of the metaphysis of the tibia could be established. Hence, tectorigenin may have antiosteoporotic effects also in postmenopausal women. Immunohistochemical staining of proliferating cell nuclear antigen--a proliferation marker--in the mammary gland did not indicate a mammotrophic effect of the tectorigenin-containing BC extract at both tested doses. In summary, tectorigenin or the B. chinensis extract containing tectorigenin had a strong hypothalamotropic and osteotropic effect but no effect in the uterus or the mammary gland. Therefore, tectorigenin may be in the future a clinically useful selective estrogen receptor modulator.

Extracts of the fruits of chaste tree (Vitex agnus castus = AC) are widely used to treat premenstrual symptoms. Double-blind placebo-controlled studies indicate that one of the most common premenstrual symptoms, i.e. premenstrual mastodynia (mastalgia) is beneficially influenced by an AC extract. In addition, numerous less rigidly controlled studies indicate that AC extracts have also beneficial effects on other psychic and somatic symptoms of the PMS. Premenstrual mastodynia is most likely due to a latent hyperprolactinemia, i.e. patients release more than physiologic amounts of prolactin in response to stressful situations and during deep sleep phases which appear to stimulate the mammary gland. Premenstrually this unphysiological prolactin release is so high that the serum prolactin levels often approach heights which are misinterpreted as prolactinomas. Since AC extracts were shown to have beneficial effects on premenstrual mastodynia serum prolactin levels in such patients were also studied in one double-blind, placebo-controlled clinical study. Serum prolactin levels were indeed reduced in the patients treated with the extract. The search for the prolactin-suppressive principle(s) yielded a number of compounds with dopaminergic properties: they bound to recombinant DA2-receptor protein and suppressed prolactin release from cultivated lactotrophs as well as in animal experiments. The search for the chemical identity of the dopaminergic compounds resulted in isolation of a number of diterpenes of which some clerodadienols were most important for the prolactin-suppressive effects. They were almost identical in their prolactin-suppressive properties than dopamine itself. Hence, it is concluded that dopaminergic compounds present in Vitex agnus castus are clinically the important compounds which improve premenstrual mastodynia and possibly also other symptoms of the premenstrual syndrome.

The sulphated glycoprotein SSG 185 is the monomeric precursor of a highly aggregated structural element in the extracellular matrix of the multicellular green alga Volvox carteri. A phosphodiester of arabinose was isolated from a saccharide fragment of SSG 185. The structure of this phosphodiester was investigated by methylation analysis, 13C-NMR, photometric methods and enzymatic assays and identified as D-Araiota-5-phospho-5-D-Araiota. The function of this phosphodiester bridge as a crosslink of different carbohydrate chains in SSG 185 is discussed.