[Tissue distribution of free anthraquinones in SD rats after orally administered extracts from raw and prepared rhubarbs].Yao Xue Xue Bao. 2011 Mar; 46(3):350-4.YX
Rhubarb anthraquinone derivatives (AQs) have been documented to have both therapeutic and toxic effect on liver and kidney, leading to a complex puzzle to assess their benefits and risks. In this study, the tissue distributions of AQs in SD rats after orally administrated extracts of raw and prepared rhubarb were examined whether they undergo different uptake. The total rhubarb extract (14.49 g x kg(-1) of body weight per day od, counted on the quantity of crude material) was administrated orally for 12 weeks. The concentrations of the AQs in different tissues were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The five major AQs, aloe-emodin, rhein, emodin, chrysophynol and physcion, could all be detected in the liver, kidney and spleen, while only rhein, aloe-emodin and emodin reached the quantitative limit. The tissue concentrations of AQs in raw rhubarb group were higher than that in steamed rhubarb group with rhein > emodin > aloe-emodin in the same tissue. On the whole, the tissue distribution of rhein was higher than that of emodin and aloe-emodin in liver, spleen and kidney. AQs could not be detected in those tissues after drug withdraw for 4 weeks, which suggested scarcely any accumulative toxicity of rhubarb. The result indicated that raw rhubarb had more tissue toxicity than steamed rhubarb and rhein may be one of the major poisonous ingredients. The results were concordant with the traditional Chinese medicine theory of toxicity-attenuating effect of processing.
