Plant‐based corosolic acid: Future anti‐diabetic drug?

Abstract

Diabetes is one of the nation's most prevalent, debilitating and costly diseases. For diabetes, frequent insulin treatment is very expensive and may increase anti‐insulin antibody production, which may cause unwanted side effects. Corosolic acid may also have some efficacy in the treatment of diabetes, but without induction of anti‐insulin antibodies. Recently, corosolic acid from Lagerstroemia speciosa L. leaf extracts has been reported to act via an indirect mechanism (unlike insulin) in animal experiments. The insulin‐complementary anti‐diabetic therapeutic value observed in these Japanese preliminary clinical trials has led to renewed interest in the biosynthesis of this compound. So far, there has been no clear evidence for a corosolic acid biosynthetic pathway in plants. This article provides possible roles of corosolic acid and hypothetical information on the biosynthetic pathway in plants.