Comparison of the tissue distributions of flavonoids after oral administration of pure baicalin, Radix scutellariae and Scutellariae-Paeoniae couple extracts to rats

摘要

Baicalin, baicalein, wogonoside and wogonin are the major ?avones ofRadix scutellariaewith various bene?cial biological activities. The purpose of this study was to investigate the tissue distribution and compare the differences of these ?avones after orally administrating the pure baicalin,R. scutellariaeandScutellariae-Paeoniaecouple extracts with the same dose of 200 mg/kg baicalin. Tissue concentrations of baicalin, baicalein, wogonoside and wogonin were determined by high performance liquid chromatography (HPLC). Organ samples including the heart, liver, spleen, lung, kidney, large intestine, small intestine and stomach were collected at three specific times (15 min, 8 h, 24 h). Unpaired Student’s t-test was used for statistical comparison. The results indicated that the baicalin, wogonoside, baicalein and wogonin all occurred in the investigated tissues after orally administrating the pure compound to the rats. Considerable concentrations of baicalein and wogonin could be detected in the investigated tissues, but were not found in rat serum. The contents of glycosides were higher than that of aglycones in small intestine, stomach, lung, heart and kidney; conversely in liver, large intestine and spleen. Pure baicalin was absorpted faster thanR. scutellariaeandScutellariae-Paeoniaecouple extracts. The concentrations of baicalin, baicalein, wogonoside and wogonin in the investigated tissues after orally administratingScutellariae-Paeoniaecouple extract (24 h) were higher (P＜0.05) than after orally administrating the pure baicalin andR. scutellariaeextract.