RESUMEN
OBJECTIVE To explore the intestinal absorption characteristics of saikosaponins. METHODS Based on everted intestinal sac model, using accumulative absorption amount (Q) and absorption rate constant (Ka) as indexes, UHPLC-MS/MS technique as a method, the absorption of saikosaponin A, B2, C, D and F from total saponins of Bupleurum chinense (8 g/mL, by crude drug) in the duodenum, jejunum and ileum was detected. RESULTS The correlation coefficients (r) of the regression equations for the absorption of saikosaponins A, B2, C and F in the duodenum, jejunum and ileum were all higher than 0.95, while the r of saikosaponin D in the above intestinal segments was lower than 0.95; compared with the absorption of the same composition in the duodenum, the Q and Ka of saikosaponin A and C circulating in jejunum and ileum for 120 min, as well as the Q and Ka of saikosaponin F circulating in the ileum for 120 min were significantly decreased (P<0.05). CONCLUSIONS Saikosaponin A and the other 4 saikosaponins are all absorbed in the duodenum, jejunum and ileum; among them, saikosaponin A, B2, C and F are linearly absorbed, which conforms to the zero-order absorption characteristics, but saikosaponin D shows non- linear absorption.