Race Dependent Effects of Black Cohosh Fractions in Human Umbilical Vein Endothelial Cells

Background: Hot flushes are the most prominent symptom of menopause. Yearly, more than 2 million women reach menopause with about half of them reporting to suffer from hot flushes within 2 years of menopause. Significant racial differences in the prevalence of hot flushes among African American, Hispanic, and Caucasian women have been reported.. Due to significant side effects these treatments are largely unpopular. Therefore, alternative therapies are becoming increasingly attractive to sufferers from hot flushes. Extracts from the plant black cohosh are a popular over-the-counter remedy sold in the United States. However, its clinical efficacy is controversial. Triterpene glycosides, thought to be the active constituent of this plant, have long since been used in the standardization of black cohosh preparations. However, recent mass spectrometric analysis of black cohosh extract has revealed an abundance of new compounds previously unknown to be present in this plant. One group of these new compounds, guanidine alkaloids, structurally pose a potential active ingredient responsible for the blunting effect on hot flushes by black cohosh. Thus, we investigated the effect of guanidine alkaloids and triterpene glycosides in a cell model of vascular endothelial cells. We assessed markers of vasomotor function thought to be related to hot flushes in cells of different racial origins. Methods: Human umbilical vein endothelial cells from donor of African American, Hispanic, and Caucasian origin were exposed to varying doses of triterpene glycosides and guanidine alkaloids. Several markers of endothelial cell biology were assessed through western blotting and ELISA assay. Results: Our results revealed that both guanidine alkaloids and triterpene glycosides differentially affect markers of vasodilatory capacity by race. Guanidine alkaloids seem to present the greatest potential to alleviate hot flushes, whereas triterpene glycosides may be useful in their capacity as a vasorelaxant in other pathologies such as hypertension. Conclusion: Current preparations of black cohosh may be inadequate in their current preparation and standardization.