A comparative study of excretion of the components after oral administra- tion of pure baicalin radix scutellariae and scutellariae-paeoniae couple extracts to normal and ulcerative colitis rats

Radix scutellariae and Scutellariae-Paeoniae couple extracts are the well-known Traditional Chinese Medicine (TCM) to treat ulcerative colitis. Baicalin, wogonoside, baicalein and wogonin are the main effective ingredients in Radix scutellariae. This study was carried out to investigate the excretion profiles of baicalin, wogonoside, baicalein and wogonin in urine and feces after oral administration of pure baicalin, Radix scutellariae and ScutellariaePaeoniae couple extracts to rats with ulcerative colitis (UC) and to compare the different profiles of urine with normal rats. The levels of the four flavones in urine and feces were measured by a rapid and sensitive high-performance liquid chromatography (HPLC) method. All the rats were divided randomly into two groups (ulcerative colitis and normal groups). Each group contained three subgroups: pure baicalin, Radix scutellariae and Scutellariae-Paeoniae couple subgroup. Each group received oral administration of pure baicalin, Radix Scutellariae and Scutellariae-Paeoniae couple extracts; which contained nearly the same amounts of baicalin at a dosage of 200 mg/kg. All the four flavones occurred in the rat urine and feces, but the general levels of baicalin and wogonoside were predominant in urine and baicalein and wogonin were predominant in feces. The cumulative excretion quantities of these flavones in rat urine or feces were significantly different among these groups (P < 0.05). Meanwhile, the cumulative excretion quantities of these flavones in UC rat urine were less than that in normal rat. Conclusion: Our results suggest that the combination of Radix Scutellariae and Radix Paeoniae Alba might afford higher absorption and excretion, and that the rate of utilization of pure baicalin, Radix scutellariae or ScutellariaePaeoniae couple is increased in UC.