[Effects of Chinese herbal medicine Danzhi Jiangtang Capsule and exercise on JNK signaling pathway in pancreatic tissues of diabetic rats].

Abstract

Objective: To explore the effects of exercise and Danzhi Jiangtang Capsule (DJC), a compound traditional herbal medicine, on the JNK signaling pathway in pancreatic tissues of diabetic rats and to investigate the possible mechanisms of exercise and DJC in treating diabetes.

Methods: Seventy-eight male Wistar rats were injected with low dose of streptozotocin and fed a high-fat diet to establish a diabetic model in rats. Then 60 diabetic rats were divided into diabetes group, exercise group, DJC group and exercise combined with DJC group. Another twelve rats were used as normal control. After eight months of treatment, the expression levels of phosphor-c-Jun N-terminal kinase (p-JNK), pancreatic and duodenal homeobox-1 (PDX-1), and insulin protein in pancreatic tissues from rats were detected by immunohistochemical method and Western blotting.

Results: In pancreatic tissues of diabetes group, the expression level of p-JNK protein was significantly higher than that in the normal group (P<0.01), and the expression levels of PDX-1 and insulin protein were significantly decreased (P<0.01). After administration of exercise and DJC, the expression level of p-JNK protein in pancreatic tissues of the diabetes group was decreased significantly, while the expression levels of PDX-1 and insulin protein were increased significantly (P<0.05 or P<0.01).

Conclusion: Exercise and DJC effectively protect isletβ-cell function in diabetic rats, which might be due to a decreased JNK signaling pathway.