Remifemin is an ethanolic extract of the rhizome of Cimicifuga racemosa (C.r.) and is used to relieve climacteric hot flushes. In the present study the effects of this preparation on LH and FSH secretion of menopausal women were investigated. After an 8 weeks treatment, LH but not FSH levels were significantly reduced in patients receiving the Cimicifuga extract. To further characterize the endocrinologically active principles of this plant extract, a lipophilic extract of C.r. was prepared and subjected to Sephadex chromatography. Fractions obtained were tested for their ability to reduce LH secretion in ovariectomized (ovx) rats and to compete in vitro with 17 beta-estradiol for estrogen receptor binding sites. Three types of endocrinologically active compounds were obtained: (1) Constituents which were not ligands for the estrogen receptor but suppress LH release after chronic treatment, (2) constituents binding to the estrogen receptor and also suppressing LH release, and (3) compounds which are ligands for the estrogen receptor but without an effect of LH release. It is concluded that the LH suppressive effect of C.r. extracts observed in menopausal women and ovx rats is caused by at least three different synergistically acting compounds.
The effects of acute stress exposure upon cholecystokinin (CCK) and substance P (SP) concentrations in discrete hypothalamic regions of the adult male rat brain were studied. Animals were exposed to foot shock stress for periods of 2, 4, 10, 30 or 60 min duration; immediately afterwards they were decapitated; brains were frozen and subsequently microdissected. CCK and SP concentrations were assayed by a specific RIA, as were serum levels of ACTH, corticosterone, PRL, GH, LH and testosterone. Stress had no effect upon SP concentrations in the anterior or posterior parts of the arcuate nucleus (ARC), but led to elevated CCK levels in the posterior ARC following 60 min of exposure. In both the ventromedial and dorsomedial hypothalamic areas, stress induced depletions of both neuropeptides. In the anterior (but not the posterior) portions of the lateral hypothalamic area, CCK and SP concentrations were reduced by stress exposure. These studies demonstrate that discrete hypothalamic CCK and SP neuronal systems are responsive to stress. This suggests that endogenous hypothalamic CCK and SP participate, along with other neurotransmitters/neuromodulators, in the integrated hypothalamic stress response, and mediate stress-neuroendocrine interactions.
The endocrine activity of compounds of the rhizome of CIMICIFUGA RACEMOSA can be demonstrated in the IN VIVO model of the ovariectomized rat as well as in the IN VITRO system of the estrogen receptor assay. A reduction of the serum levels of luteinizing hormone in ovariectomized rats takes place upon application of a methanol-extract. This extract contains substances, which are able to bind to estrogen receptors of rat uteri. Using the estrogen receptor assay as a pharmacological testsystem to determine the activity of different fractions, the chromatographic separation of the methanol-extract resulted in at least three different endocrine active compounds. One of these could be identified as the isoflavon Formononetine. The endocrine activity of this isoflavon was characterized in both described testsystems. It can be shown that Formononetine is a competitor in the estrogen receptor assay, but failed to reduce the serum levels of luteinizing hormone in overiectomized rats.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.