Black Cohosh (<i>Actaea racemosa</i> L.) Improves Serum Lipid Profiles and Vasomotor Responses in Ovariectomized Rats

Abstract

We investigated the effects of long-term administration of black cohosh extract (BcEx) on serum lipid profiles and vasomotor responses in ovariectomized (OVX) rats and compared them with those of rats administered 17β-estradiol (E2) or raloxifene, a selective estrogen receptor modulator. Vehicle (OVX-or sham-control), BcEx (0.5 or 3.0 mg/kg/day), E2 (0.5 mg/kg/day), or raloxifene (2.5 mg/kg/day) were injected subcutaneously for 5 weeks, and serum lipid profiles and vasomotor responses were measured at the end of the treatment. BcEx lowered total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels, but did not affect high-density lipoprotein cholesterol or triglyceride (TG) levels. Raloxifene showed a similar effect to that of BcEx, while E2 attenuated the increase in TC and LDL-C levels and significantly increased TG levels. The vascular relaxation induced by carbachol increased significantly in norepinephrine-precontracted aortic rings isolated from BcEx-, E2-, or raloxifene-treated rats. No change in uterine weight was observed in the BcEx-treated group. The raloxifene-treated group showed a similar trend as that of the BcEx-treated group, but E2 significantly increased uterine weight. These results suggest that long-term administration of BcEx behaves similar to the selective estrogen receptor modulator raloxifene.