Editor's Note
Rhizoma Coptidis  (RC), one of the most commonly used  traditional Chinese medicines , has been applied to treat diabetes in clinics for thousands of years. Numerous studies showed that RC alkaloids balanced the glucose homeostasis not only by widely recognizing insulin resistance pathways, but also by promoting insulin secretion, regulating  intestinal hormones , ameliorating gut microbiota structures and many other ways. This review systematically summarizes the mechanisms of RC alkaloids in treating hyperglycemia and  diabetic nephropathy  to provide a deeper understanding of these natural alkaloids. In addition, the important role of gut microbiota associated with the glucose metabolism is also reviewed.
Abstract

Hyperglycemia  is a common  endocrine system disease , which seriously affects people's health with a increasing  morbidity  in recent years.  Rhizoma Coptidis  (RC), one of the most commonly used  traditional Chinese medicines , has been applied to treat diabetes in clinic for thousands of years. Since scientists demonstrated that alkaloids from RC owned the amazing anti-hyperglycemia activities 30 years ago, these compounds have been widely used for the treatment of diabetes and hyperglycemia with unconspicuous toxicities and side effects. With the help of molecular biology, immunology and other techniques, the mechanisms about anti-hyperglycemia effect of RC alkaloids have been extensively discussed. Numerous studies showed that RC alkaloids balanced the glucose homeostasis not only by widely recognizing insulin resistance pathways, but also by promoting insulin secretion, regulating  intestinal hormones , ameliorating gut microbiota structures and many other ways. In this review, we combine the latest advances and systematically summarize the mechanisms of RC alkaloids in treating hyperglycemia and  diabetic nephropathy  to provide a deeper understanding of these natural alkaloids. In addition, the important role of gut microbiota associated with the glucose metabolism is also reviewed.