Palm leaf catechins improved insulin-related pathways in diabetic rats

Abstract

Catechin-rich oil-palm leaf extract (OPLE) (Elaeis guineensis) was previously demonstrated to possess benefits for diabetes and cardio metabolic health (vasodilation, antioxidant, cardiovascular, anti-hypertensive, anti-inflammatory, hepatoprotective and nephroprotective properties) in animal models. For insights into OPLE anti-diabetic mode-of-action and possible toxicity, the effects of dietary OPLE on insulin-signaling pathways mRNA expressions in the liver, kidney, pancreas, and spleen of normal and diabetic rats were examined. Type-2-Diabetes Mellitus (T2DM) were induced by chronic high-fat diet and streptozotocin (35 mg/kg) intraperitoneal injection. The OPLE (100 mg/kg body weight) were fed daily to normal and T2DM-induced rats. The OPLE suppressed hyperglycaemia and excessive weight gain in the T2DM rats, and appeared harmless to normal rats. The OPLE supplementation significantly (p<0.05) modulated the mRNA expressions of phosphatidylinositol-3 kinase (PIK3R1); insulin signaling receptor (INSR); insulin-receptor substrates 1 and 2; and ectonucleotide pyrophosphatase-1 (ENPP1) especially in the livers of normal rats and the spleen of diabetic rats. Results suggested the OPLE probably help prevent diabetes in healthy mammals and ameliorate the immune functions of diabetic mammals. The OPLE improved the antioxidant defence responses, insulin-pathways mRNA expressions in the normal and diabetic rats; suppressed hyperglycaemia and excessive weight gain in T2DM rodents without observable liver or kidney toxicity at the dose used.