Modified Xiaochaihu Decoction(小柴胡汤)Prevents the Progression of Chronic Pancreatitis in Rats Possibly by Inhibiting Transforming Growth Factor-β 1/Sma-and Mad-Related Proteins Signaling Pathway

Objective： To investigate the effect of modified Xiaochaihu Decoction （小柴胡汤, MXD） on transforming growth factor- [3 1/Sma- and Mad-related proteins （TGF- 13 1/Smads） signaling pathway in rats with chronic pancreatitis （CP） induced by dibutyltin dichloride. Methods： Thirty healthy male Wistar rats were randomly divided into the normal control group, CP group and CP＋MXD-treated group. CP was induced by injection of dibutyltin dichloride （DBTC, 7 mg/kg of body weight） into the right caudal vein, and the control rats were treated with vehicle. MXD was given daily by gavage at a dose of 10 g/kg of body weight, starting from the day after CP induction. After 28-day treatment, the n-benzoyl-tyrosyl para-aminobenzoic acid （NBT-PABA） test was carried out to evaluate exocrine pancreatic function. Then, rats were sacrificed, and pancreatic tissues were harvested for histological evaluation. In addition, the mRNA expression of TGF- β 1, TGF- β 1 type Ⅱ receptor （TGF β R 11 ）, Smad3 and Smad7 was determined in pancreatic tissues by using real-time polymerase chain reaction. Results： Treatment of CP with MXD improved the PABA recovery, decreased the histological lesion, and reduced the mRNA expression of TGF- β 1, TGF β R 11 and Smad3 （P〈0.05）. However, MXD had no effect on Smad7 mRNA level. Conclusions： MXD could protect the pancreas against chronic injury and improve pancreatic exocrine function in DBTC induced rat CP model. Its mechanism may involve inhibition of the TGF-β 1/Smads signaling pathway.