Active ingredients of traditional Chinese medicine in the treatment of diabetes and diabetic complications

Introduction: Diabetes mellitus (DM) is a chronic progressive systemic disease caused by metabolic disorder. In recent years, significant amounts of studies have shown that traditional Chinese medicine (TCM) and its active ingredients have obvious hypoglycemic effect. Areas covered: This paper summarizes single herbs and their active ingredients from TCM with the role of treating DM, and relevant literatures published in the past decades are reviewed. The active ingredients are divided into polysaccharides, saponins, alkaloids, flavonoids, terpenoids and others, which are described in this article from the aspects of active ingredients, sources, models, efficacy, and mechanisms. Expert opinion: Mechanisms of TCM in treating DM are concluded: i) to promote insulin secretion and increase serum insulin levels; ii) to increase the sensitivity of insulin and improve its resistance; iii) to inhibit glucose absorption; iv) to affect glucose metabolism of insulin receptor; and v) to scavenge radicals and prevent lipid peroxidation. The separation and extraction of effective monomer from TCM is an important direction of anti-diabetic drug discovery currently. Future research about hypoglycemic mechanism of TCM based on the clinical should combine with modern scientific methods and regulatory approach to strive for more meaningful discovery and innovation.