Hypoglycemic effects of sesquiterpene lactones from Byrsonima crassifolia

The novel dimeric guaianolides sesquiterpene lactone Byrsoninas A and B from seed hexane extract of Byrsonima crassifolia were identified. Streptozotocin-induced mildly diabetic and severely diabetic mice were treated with these oral administrations at a dosage of 20 mg/kg of body weight per day for 30 days. Also the protective effect in vitro in RIN-5F cells against oxidative stress was investigated and TNF-? and IL-6 levels were measured. Both Byrsonina types reduced blood glucose, cholesterol, triglyceride, lipoprotein, and transaminase levels and increased HDL-cholesterol, antioxidant enzymes, and TBARS-reactive substance levels. Byrsoninas A and B both improved this glucose metabolism by reducing insulin resistance and by stimulating insulin production due to protection effect for pancreatic ?-cells against oxidative stress, lipid abnormalities were reduced and, chronic inflammation responses were alleviated producing a hepatoprotective role.