Journal of Ethnopharmacology, vol. 96, no. 3, pp. 411-415
During a screening of medicinal plants for inhibition of protein tyrosine phosphatase1B (PTP1B), an extract from Psidium guajava (Myrtaceae) leaves exhibited significant inhibitory effect on PTP1B. Thus, its antidiabetic effect on Leprdb/Leprdb mice was evaluated. Significant blood glucose lowering effects of the extract were observed after intraperitoneal injection of the extract at a dose of 10 mg/kg in both 1- and 3-month-old Leprdb/Leprdb mice. In addition, histological analysis of the liver from the butanol-soluble fraction treated Leprdb/Lepr db mice revealed a significant decrease in the number of lipid droplets compared to the control mice. Taken together, it was suggested that the extract from Psidium guajava leaves possesses antidiabetic effect in type 2 diabetic mice model and these effect is, at least in part, mediated via the inhibition of PTP1B.