Toxicity of raw and processed roots of Polygonum multiflorum

The roots of Polygonum multillorum (Chinese name: He-Shou-Wu. HSW) are used in traditional Chinese medicine for many diseases in processed form or raw state. There are reports dealing with the toxicity of HSW. However, the toxicity is caused by over dosage or by the herb itself remains unclear. We evaluated the toxicity of raw and processed HSW on Kunming (KM) mice. For raw HSW, the toxicity of water decocta is much higher than that of acetone extract. Meanwhile, the toxicity of acetone extract of raw HSW is considerably higher than that of acetone extract of processed HSW. HPLC analyses revealed that the contents of characteristic compounds in raw HSW were changed after processing: the content of 2.3.4'.5-tetrahydroxystilbene 2-O-beta-D-glucoside was decreased by 55.8%, whereas the content of emodin was increased by 34.0%. Thus, processing could reduce the toxicity of HSW. Thus, the toxicity of HSW does not depend on the content of anthranoid derivatives, it may be correlated with the content of tetrahydroxystilbene glucosides. (C) 2011 Elsevier B.V. All rights reserved.