The effects and mechanisms of glycyrrhizin on the TNBS-induced pancreatic fibrosis in rat / 中国药理学通报

ABSTRACT

AIM To investigate the effects and possible mechanism s of Glycyrrhizin on rat pancreatic fibrosis induced by TNBS (trinitrobenzenesulfonic acid, TNBS ). METHODS Chronic pancreatitis model was induced in male Sprague -Dawley rats by injection of 2% TNBS into bile duct. All the rats were randomly divided into two groups. The rats in Glycyrrhizin intervention group were treat ed with Glycyrrhizin 8 mg?kg -1 by injection into tail vein from day 3 to day 28, while the rats in control group were administrated with same volume of saline vehicle. Ten rats in the Glycyrrhizin intervention group and eight rats in the control group wer e sacrificed on day 29, the blood was collected to determine amylase and hyaluro nic acid by enzyme dynamic and RIA method. The histological change of pancreatic tissue was evaluated by H&E stain and modified Van-Gieson stain. Mast cell in pancreas was stained by thionine blue. Expression of TGF-? 1,Collagen Ⅰ and ?-SMA in pancreas were assessed by immunohistochemistry and western blot. RESULTS In the Glycyrrhizin intervention group, the mast cell number and the percentage of degranulation decreased significantly, and the expression of ?-SMA protein also decreased compared to the control group, but there was no difference in amylase or hyaluronic acid between the treatment group and the control group. In the Glycyrrhizin intervention group, inflammation and fibrosis were ameliorated and expression of collageⅠ and TGF-? 1 was also decreased significantly compared to the control group. CONCLUSION Glycyrrhizin inhibits pancreatic fibrosis in chronic pancreatitis rats induced by TNBS. This action might be related to protecting pancreatic acinus cells from being destructed by mast cell activation and inhibiting extracellular matrix synthesis stimulated by pancreatic stellate cell.