OBJECTIVETo investigate the dosage-efficacy/toxicity relationship of prepared rhubarb, in order to explore the bidirectional effects in hepatoprotection and hepatotoxicity of prepared rhubarb and the objective authenticity for attenuating toxicity by processing.

METHODNormal and pathological animals were adopted simultaneous to investigate the effect of total extracts from prepared rhubarb within a high dose range (2.0, 5.4, 14.7, 40.0 g x kg(-1) x d(-1)) on normal state, biochemical index and histopathology of experimental animals. The factor analytic approach was used to analyze the dosage-efficacy/toxicity relationship of prepared rhubarb.

RESULTThe factor analytic approach was used to extract two common factors from the nine biochemical indexes. The firs common factor was mainly dominated by HA, LN and TGF-β1, and could be explained as fibrotic factors. The second common factor was mainly dominated by ALT, AST and ALP, and could be explained as cellular factor. The results of the factor analysis suggested that prepared rhubarb showed significant bidirectional effects in hepatoprotection and hepatotoxicity, which could protect liver in CC14 injured chronic hepatic injury, but had a certain hepatotoxic effect to normal animals. The pathological examination showed consistent results with the factor analysis. Under comparable dosages, prepared rhubarb showed a stronger liver protecting effect than crude rhubarb, with a lower toxicity.

CONCLUSIONAlthough prepared rhubarb has a certain hepatotoxic effect to normal animals, it has also a significant therapeutic effect to animals with liver injury. The results proved the symptom-based prescription theory and the scientificity of the symptom-based medication. The symptom-based prescription theory is important to correctly realize the dosage-efficacy/toxicity relationship of traditional Chinese medicines and guide the symptom-based medication.