Acute and subacute toxicity of the extract of Aristolochiae fructus and honey-fried Aristolochiae fructus in rodents.

Aristolochiae Fructus (AF) and honey-fried Aristolochiae Fructus (HAF) have been used in China for thousands of years as an anti-tussive and expectorant drug. Few clinical cases were reported associated with the toxicity of AF and HAF, although relatively high contents of aristolochic acids (AAs) were found in them. This work was designed to compare the acute and subacute toxicity of AF and HAF in order to provide references for safe clinical use and to evaluate the possibility of reducing toxicity of AF by honey-processing. The extracts of the herb were fed to mice or rats via gastric tube. Various toxic signs and symptoms, body weights, serum biochemical assay, organ weights and histopathology were used to evaluate the toxic effects. The median lethal dose (LD50) of AF and HAF are 34.1±7.2 g/kg/d and 62.6±8.0 g/kg/d with a 95% average trustable probability (p=0.95), respectively. The subacute results showed a dose-dependant relationship of the toxicity of AF and HAF. Even in the high dose groups, only moderate toxicity was observed. Honey-frying and decoction with water can decrease the contents of AAs, and attenuate the toxic effects of AF. But sufficient attention should be still paid to the safety of AF and HAF due to the existence of AAs.