Scientific African (Nov 2020)
The lyophilized aqueous leaf extract of Moringa oleifera blunts streptozocin-induced diabetes in rats through upregulation of GLUT 4 signaling pathway and anti-oxidant effect
Abstract
The anti-diabetic property of aqueous leaf extract of Moringa oleifera was performed in streptozocin-induced diabetic rats using serum chemistry, histology and immunochemical parameters as indices of diabetes. The blood glucose level of the diabetic untreated group continues to increase while that of the treated group after 21 days decreased. While the animals in the diabetic untreated group experienced increase in the levels of markers of organ damage when compared to the control group (P values < 0.0001). ALT increased from 61.83±1.5 to 96.1±22.4, AST was 225.1±26.6 from 172.6±13.9, ALP 13.5±0.006 to 13.6±0.002, UREA 1.0±0.08 to 3.0±0.4, their reduction was observed in the extract-treated groups. ALT reduced from 96.1±22.4 to 73.70±9.7; AST from 225.1±26.6 to 184.4±18.2; ALP from 13.6±0.002 to 13.6±0.01; UREA from 3.0±0.4 to 2.0±0.4. Treatment with the extract significantly reduced markers of oxidative stress in the kidney [hydrogen peroxide (898.8±6.26 to 688.0±13.7), malondialdehyde (640±0.1 to 600±0.2) and protein carbonyl (548.4±1.5 to 458.1±1.6)]; heart [hydrogen peroxide (389.4±1.8 to 358.2±1.5), malondialdehyde (264.0±0.5 to 122.0±0.3), protein carbonyl (196.8±0.5 to 162.7±3.5)]; and liver [hydrogen peroxide (119.36±3.2 to 103.94±10.7), malondialdehyde (236.0±0.4 to 73.0±0.2), protein carbonyl (269.3±1.0 to 174.2±1.1) respectively. The levels of antioxidants were reduced in the diabetic untreated group but there was increase in the Moringa treated group. Glucose transporter 4 (GLUT 4) was down regulated in the diabetic untreated group while it was well expressed in the treated groups. The histology of pancreas and liver showed varied levels of infiltration of inflammatory cells, congestion and necrotic lesions, but these were mild in the treated groups. The result shows that the extract does have an anti-diabetic effect with the decrease in the levels of blood glucose and markers of oxidative stress as well as increase in the amount of antioxidants in the treated group when compared to the diabetic untreated group. More importantly, the extract caused upregulation of GLUT 4, which is relevant in reversing insulin resistance in the same manner as pioglitazone, the standard antidiabetic agent used in this study.
