In situ intestinal absorption of flavonoids from Hedyotis diffusa in rats / 中草药

ABSTRACT

Objective: To investigate the intestinal absorption characteristics of five kinds of flavonoids from Hedyotis diffusa extract in rats. Methods: The in situ rat single-pass intestinal perfusion model was used. The contents of rutin, isoquercitrin, quercetin, kaempferol, and quercetin in perfusates were determined by HPLC-DAD, and the rat intestinal absorption parameters of flavonoids were calculated. Results: In perfusion model, the effective permeability coefficients (Peff) of all components were low. The absorption rate constant (Ka) and Peff had no significant difference when the concentration of total flavonoids from H. diffusa was 0.5-4.0 g/L. In the 2.0 g/L concentration, Ka of rutin, isoquercitrin, quercetin, kaempferol, and quercetin were 0.0113, 0.0154, 0.0102, 0.0305, and 0.0275 min-1, respectively; The Ka sequences of rutin and isoquercitrin in different intestinal segments were ileum > duodenum > jejunum ≈ colon and jejunum > duodenum > ileum ≈ colon. Conclusion: The absorption of the five flavonoids from H. diffusae is a first-order process with the passive diffusion mechanism. The absorption rates of each flavonoid are significantly different. The absorption rate of flavonoid glycosides is lower than that of aglycones. The flavonoids from H. diffusa could be absorbed in all the intestinal segments. The best parts of intestine to absorb rutin and isoquercitrin are ileum and jejunum.