Hot-water-extracts of Polygonum Multiflorum Do Not Induce Any Toxicity but Elicit Limited Beneficial Effects on the Liver in Mice

Shou-Wu-Pian, a herbal remedy formulated from Polygonum multiflorum (PM), has been extensively used for the treatment of hair-loss, constipation and vertigo in Asia, Europe and U.S.A. Although recent reports have indicated severe liver damage occurred after taking Shou-Wu-Pian in humans, studies on the hepatotoxicity of this herbal remedy have been limited, and this organ-specific adverse effect induced by PM intake remains to be confirmed. In this study, hepatotoxicity of hot-water-extracted PM was investigated in vitro and in vivo in mice. After treating primary cultured hepatocytes with PM extracts at 3 final concentrations (0.5, 1 and 5 mg/ml) with or without acetaminophen (10 mM) for 24 hr, no cytotoxic effects were observed. In fact, cell viability and lactate dehydrogenase leakage were significantly improved at the highest PM extracts dose compared with controls. Mice orally administered twice daily with the PM extracts (20 or 340 mg extracts/mouse × 2) for 10 days indicated no unfavorable effect on the liver function. Only when mice subchronically received the higher dose of the PM extracts (340 mg) before treatment with a single-bolus dose of acetaminophen (500 mg/kg; i.p.), attenuation of acetaminophen-induced hepatotoxicity was significantly established in vivo. The results in the present study contradicted hepatotoxic findings reported in humans; PM extracts do not induce any toxicological effects, at least on the liver, and may in fact elicit useful but limited beneficial effects on the liver in vivo.