Investigation on the absorption of phillyrin and forsythiaside in rat digestive tract.

In the present study, an in situ rat model was employed to systemically investigate the absorption of phillyrin and forsythiaisde. Three concentrations of phillyrin (0.2, 0.4 and 1.5 mg) were tested and the results showed that phillyrin cannot be absorbed in the digestive tract. The absorption rates of forsythiaside in stomach were 7.773, 7.228 and 6.751% h(-1) for 0.5, 1 and 2.5 mg, and no significant difference was found in different concentrations. The absorptions of forsythiaside in intestine were investigated in different concentrations and different absorption sites. The mean P% were 6.618, 7.199, 9.210 and 9.747% h(-1) of forsythiaside in intestine for 0.25, 0.5, 1, 2.5 mg dosage, and the statistical analysis showed that the absorption had no relation with concentration. In addition, in different digestive segments, the mean P% were 7.528, 8.382, 8.191, 9.109 and 6.908% h(-1) for the gastric, duodenum, jejunum, ileum and colon, respectively. No statistical differences of absorption were found for forsythiaside among different digestive segments indicated no specific absorption site was found.