A Protein Isolate from Moringa oleifera Leaves Has Hypoglycemic and Antioxidant Effects in Alloxan-Induced Diabetic Mice

Abstract

Moringa oleifera has been used in traditional medicine to treat diabetes. However, few studies have been conducted to relate its antidiabetic properties to proteins. In this study, a leaf protein isolate was obtained from M. oleifera leaves, named Mo-LPI, and the hypoglycemic and antioxidant effects on alloxan-induced diabetic mice were assessed. Mo-LPI was obtained by aqueous extraction, ammonium sulphate precipitation and dialysis. The electrophoresis profile and proteolytic hydrolysis confirmed its protein nature. Mo-LPI showed hemagglutinating activity, cross-reaction with anti-insulin antibodies and precipitation after zinc addition. Single-dose intraperitoneal (i.p.) administration of Mo-LPI (500 mg/kg·bw) reduced the blood glucose level (reductions of 34.3%, 60.9% and 66.4% after 1, 3 and 5 h, respectively). The effect of Mo-LPI was also evidenced in the repeated dose test with a 56.2% reduction in the blood glucose level on the 7th day after i.p. administration. Mo-LPI did not stimulate insulin secretion in diabetic mice. Mo-LPI was also effective in reducing the oxidative stress in diabetic mice by a decrease in malondialdehyde level and increase in catalase activity. Mo-LPI (2500 mg/kg·bw) did not cause acute toxicity to mice. Mo-LPI is a promising alternative or complementary agent to treat diabetes.

Effects of Moringa oleifera on Glycaemia and Insulin Levels: A Review of Animal and Human Studies

“…While a decrease in insulin levels was reported in a Wistar rat model for polycystic ovary syndrome treated with MO aqueous leaf extract, although this last study failed to measure glycemic levels [76]. Furthermore, no changes in insulin were reported in the works by Azad et al [9], Olurishe et al [67], Paula et al [59], and López et al [58]. These variations in obtained results regarding insulin may be explained by the diverse experimental conditions in the studies, where tree parts, animal model, and MO doses were different (Table 1).…”

“…A protein isolate obtained from MO leaves (57.5% of the soluble protein of the leaf extract) was studied in alloxan-induced (150 mg/kg, i.p.) male diabetic mice [59]. A single i.p.…”

Moringa oleiferaand glycemic control: A review of current evidence and possible mechanisms

“…Regarding the toxicity of Mo ‐LPI, no adverse effects were observed in the mice even at a dose of 2,500 mg/kg. In addition, Mo ‐LPI showed no significant effect on insulin secretion in the diabetic mice (Paula et al, ).…”

Biological, nutritional, and therapeutic significance of Moringa oleifera Lam

“…A protein had antigenic epitopes like insulin reported in seed coat and leaves of MO and showed hypoglycemic properties on oral administration. It also cross‐reacted with anti‐insulin antibodies, which proved that it might have antigenic epitopes similar to insulin (Paula et al, ). Leaf methanolic extract indicated defensive activity against diabetic‐prompted renal damage, receptive oxygen species, and irritation (Omodanisi et al, ).…”

“…Leaf powder capsules (4 g) induced the discharge of insulin (Anthanont et al, ). The action of CD69, INF‐g, and CD44 protein is increased by oral administration of leaf aqueous extract, which are responsible for hypoglycemic activity and furthermore decreased creatinine and urea levels from damaged kidneys (Paula et al, ). The reduction in lipid peroxidation and immunoglobulin IgG and IgA was observed for seed extract (Al‐Malki & El Rabey, ).…”