INS and obesity due to melanocortin 4 receptor deficiency: Mechanistic studies have shown that triterpenoid compounds such as OA act as hypoglycaemic and anti-obesity agents mainly through (i) reducing the intestinal absorption of glucose; (ii) decreasing endogenous glucose production such as hepatic gluconeogenesis; (iii) increasing insulin sensitivity; (iv) improving lipid metabolism; and (v) promoting body weight loss [90].