Objective: To observe the effects of Lizhong Decoction on expression and transport ability of PepT1 in Caco-2 cells. Method :Caco2 monolayers were grown on permeable supports. Peptide transport activity was studied using -glycyl-sarcosine( -Gly-Sar). The densities of PepT1 protein and mRNA(SLC15A1)expression levels were analyzed by Western blot and real-time quantitative Polymerase Chain Reaction. Result: The total transported Gly-Sar of Caco-2 cells within 15

30

60

120 min of group treated by Lizhong Decoction were higher than those of controlled group

(4.52±0.57)

(6.34±0.57)

(7.29±0.64)

(8.23±0.67) μmol/ well vs (2.42±0.68)

(3.15±0.76)

(5.62±0.20)

(6.54±0.54) μmol/ well. The group of Lizhong Decoction together with Rp-8-Br-cAMP at 15

30

120 min. were 2.68±0.46

4.13±0.46

6.73±0.43 μmol/p well. The figures were significantly lower than that of Lizhong Decoction olone.The PepT1 protein expression level of cells treated with Lizhong Decoction was higher that of control. Conclusion: Lizhong Decoction has significant effects on promoting the transport ability of dipeptides in Caco-2 cells

which maybe take effects by inducing the plasmatic PepT1 protein to insert to cell membrane.