Effects of Chinese herbal medicines on spontaneous chronic pancreatitis in rats and the pathological relationships between formulas and syndromes

Objective To investigate the effects of Guizhi Decoction, Chaihu Guizhi Decoction, Xiaochaihu Decoction and camostat on rat spontaneous chronic pancreatitis and the pathological relationships between formulas and syndromes. Methods Fifty-seven male WBN/Kob rats at age of 4 weeks were divided into five groups: untreated group (n=18), Guizhi Decoction-treated group (n=9), Chaihu Guizhi Decoction-treated group (n=9), Xiaochaihu Decoction-treated group (n=9) and camostat-treated group (n=12). The rats in each group were fed with corresponding drugs for 12 weeks. The pancreatic wet weight and histopathological changes of pancreatic tissue were observed every four weeks. Meanwhile, the expression level of pancreatitis-associated protein (PAP) in pancreas was detected by RT-PCR technique and immunohistochemical method. Results In the untreated group, the histopathological changes in pancreas were observed in rats at 12-week age, while such changes were absent in the Guizhi Decoction-treated group. The histopathological changes in pancreas were quite remarkable in rats at 16-week age in both the Xiaochaihu Decoction-treated and the camostat-treated groups. The expression level of PAP mRNA was lower in the Guizhi Decoction-treated group than those in the other groups. The PAP expressions were absent in rats at 12-week age in the Guizhi Decoction-treated and the Chaihu Guizhi Decocion-treated groups. Conclusion Guizhi Decoction, Chaihu Guizhi Decoction, Xiaochaihu Decoction and camostat are all beneficial to prevention and cure of chronic pancreatitis, and Guizhi Decoction is the most effective one. It is speculated that Taiyang exterior syndrome may be the pathogenesis of basic syndrome may be the pathogenesis of basic syndrome of spontaneous chronic pancreatitis, and the expression of PAP may be its pathological basis.