RESUMO
The aim of this study was to investigate the pharmacokinetic profiles of baicalin, wogonoside, baicalein and wogonin after oral administration of pure baicalin, Radix scutellariae and Scutellariae-Paeoniae couple extracts were administered and the pharmacokinetics profiles were compared between normal and ulcerative colitis rats. The plasma concentrations of the four flavonoids were determined by using a simple and rapid high-performance liquid chromatography 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 extracts subgroup. Each group received oral administration of pure baicalin, Radix scutellariae and Scutellariae-paeoniae couple extracts at the same dose of 200 mg/kg baicalin. The results showed that wogonoside, possibily as a methylated product of baicalin, was found in plasma after oral administration of pure baicalin or formulas to rats. Baicalin and wogonoside demonstrated bimodal phenomenon. Baicalin and wogonoside in Scutellariae-Paeoniae couple extract had shown better absorption than which inpure baicalin and Radix scutellariae extract. Whether oral administration of pure baicalin, Radix Scutellariae or Scutellariae-paeoniae couple extracts, ulcerative colitis rats showed better absorption than normal rats. For example AUC[0-t] of baicalin were: [41.46 +/- 0.62], [59.12 +/- 6.42] and [104.87 +/- 0.86] [micro g/mL] h in UC groups vs [17.77 +/- 0.66], [28.04 +/- 4.06] and [49.01 +/- 4.61] [micro g/mL] h in normal groups, respectively. The pharmacokinetics properties of the four flavonoids differed between ulcerative colitis and normal rats, including AUC[0-t] and C[max] [p < 0.05]