Experimental study on the effect of tibetan medicine triphala on the proliferation and apoptosis of pancreatic islet β cells through incretin-cAMP signaling pathway

Abstract

According to the data, there are 387 million people with diabetes in the world, and the number of people with diabetes is expected to reach 600 million by 2035 (Nature Reviews Endocrinology, 14, 2018, Zheng et al.). At present, there are nearly 110 million diabetic patients in China, the incidence of which is increasing (Diabetologia, 61, 2018, Ma). Islet β cell apoptosis and proliferation is an important basis for the occurrence and development of diabetes. It has been reported that enhancing the activity of incretin-cAMP signaling pathway can also promote islet β cell proliferation, reduce β cell apoptosis and promote insulin secretion (Diabetologia, 59, 2016, Iida et al.). Tibetan medicine Triphala (THL) is a traditional national medicine, it plays a good role in anti-fatigue, antioxidation, prevention and treatment of polycythemia at high altitude. Research have shown that it can reduce blood glucose in patients with diabetes and inhibit the activity of glucosidase in the intestines (The Journal of Alternative and Complementary Medicine, 23, 2017, Peterson et al.). After the diabetic Wistar rat model induced by Streptozocin (STZ) was successfully duplicated, the positive drug sitagliptin tablet and THL were given and the changes of body weight and blood glucose were measured. After 6 weeks, the expression of related factors in serum and pancreas was observed. Compared with the model group, in the treatment group, blood glucose decreased, body weight increased, incretin-cAMP signaling pathway related factors glucose-dependent insulin-promoting polypeptide (GIP), glucagon-like peptide-1 (GLP-1), GLP-1R, cAMP, P-protein kinase A (PKA), AKT were up-regulated, insulin secretion was increased, liporing protein interaction protein (TXNIP) expression was down-regulated. In addition, in the treatment group, the degree of islet atrophy was alleviated and the number of islet β cells increased. This study shows that THL may enhance the activity of incretin-cAMP signal pathway and affect the proliferation and apoptosis of islet β cells, so as to achieve the effect of anti-diabetes.