Hepatic effects of Cimicifuga racemosa extract in vivo and in vitro

Extracts of Cimicifuga racemosa are used frequently for menopausal complaints. Cimicifuga is well tolerated but can occasionally cause liver injury. To assess hepatotoxicity of cimicifuga in more detail, ethanolic C. racemosa extract was administered orally to rats, and liver sections were analyzed by electron microscopy. Tests for cytotoxicity, mitochondrial toxicity and apoptosis/necrosis were performed using HepG2 cells. Mitochondrial toxicity was studied using isolated rat liver mitochondria. Microvesicular steatosis was found in rats treated with > 500 mu g/kg body weight cimicifuga extract. In vitro, cytotoxicity was apparent at concentrations >= 75 mu g/mL, and mitochondrial P-oxidation was impaired at concentrations >= 10 mu g/mL. The mitochondrial membrane potential was decreased at concentrations >= 100 mu g/mL, and oxidative phosphorylation was impaired at concentrations >= 300 mu g/mL. The mechanism of cell death was predominantly apoptosis. C. racemosa exerts toxicity in vivo and in vitro, eventually resulting in apoptotic cell death. The results are compatible with idiosyncratic hepatotoxicity as observed in patients treated with cimicifuga extracts.