Protective role of Moringa oleifera leaf extract on cardiac antioxidant status and lipid peroxidation in streptozotocin induced diabetic rats

Abstract

Moringa oleifera is a medicinal plant with great therapeutic potential. The leaves of Moringa oleifera are used by Indians in herbal medicines to treat diabetes. The present study is aimed to determine the protective role of Moringa oleifera in cardiac tissues under diabetic conditions. Diabetic rats were treated orally with methanolic extract of Moringa oleifera leaves at a dose of 300 mg/Kg body weight for 60 days. The effect of extract on serum glucose, glycated hemoglobin, plasma insulin and the levels of thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP), conjugated dienes (D), activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-reductase (GRD) and reduced glutathione content (GSH) were estiated. Metformin and atorvastatin were used as standard drugs. A significant increase in plasma insulin, activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-reductase (GRD) and reduced glutathione content (GSH) and a significant decrease in serum glucose, glycated hemoglobin, thiobarbituric acid reactive substances (TBARS), hydroperoxides (HP) and conjugated dienes (CD) were observed in the treated groups. This study evaluated the antioxidant potential of methanolic extract of Moringa oleifera leaves. These findings suggest the protective role of Moringa oleifera against oxidative stress in the heart of diabetic rats.

Potential of Moringa oleifera to Improve Glucose Control for the Prevention of Diabetes and Related Metabolic Alterations: A Systematic Review of Animal and Human Studies

“…In this sense, lower fasting blood glucose levels were found in both STZ-induced diabetic rats and normal rats after administration of 250 mg/kg MO methanolic extract (Nigeria cultivar) daily for 6 weeks compared to their respective control rats [57]. Coincident results were found in a similar model in two different works with Indian MO; the first one an 8-wk intervention with the methanolic extract (300 mg/kg) [59] and the second one with a methanolic extract from pods instead of leaves (150 mg/kg or 300 mg/kg), which was orally administered for 3 weeks [60]. An increase in insulin was also noted in both of these experiments.…”

“…Indeed, these parts of MO are able to repair the high levels of oxidative stress that are intrinsic to the chemical induction of diabetes in the animal models and in animals fed a very high-fat diet. This effect has also been observed with plant extracts, both aqueous and obtained with organic solvents, and documented in many different organs, such as the liver [46,52,61], kidney [57], pancreas [50], brain [76] and heart [59]. The election method employed to test the antioxidant capacity in these organs is the measurement of lipid peroxidation through the formation of MDA, which is consistently diminished in diabetic animals treated with MO compared to untreated animals.…”

“…The election method employed to test the antioxidant capacity in these organs is the measurement of lipid peroxidation through the formation of MDA, which is consistently diminished in diabetic animals treated with MO compared to untreated animals. This might be explained by the effect of MO on the activity of antioxidant enzymes, since many study results confirm that MO and its extracts can reverse the decrease in SOD, catalase (CAT) [42,46,52,59,60,76] and GSH-Px [41,59] observed in diabetic animals compared to the negative control, as well as increase the non-enzymatic antioxidant system GSH (reduced glutathion) [41,42,46,50,[59][60][61], which is also decreased in the diabetic condition. The results, as shown in Table 3, are very consistent among studies and in all type of organs; only Paula et al study [53], performed with a protein isolate of MO leaves, showed increase in CAT but no effect on SOD activity, perhaps due to a short treatment duration of only 7 days.…”

“…Lack of consistency is also found regarding the effect of MO methanolic or aqueous extracts on fasting blood glucose when administered to normal rats. Some studies report decreased values [58] while more frequently, works report no changes [40,43,49,59], although, once again, the intervention period has different durations.…”

Propriedades terapêuticas da Moringa oleífera Lam. no tratamento do diabetes mellitus

“…Além disso, foi visto que os níveis das enzimas antioxidantes endógenas foram significativamente aumentados tanto no grupo tratado com o extrato como no grupo dos medicamentos, em comparação com os grupos controle diabético e dieta rica em energia. Em adição, percebeu-se redução na hemoglobina glicada e em (Aju;Rajalakshm;Mini, 2019) substâncias reativas ao ácido tiobarbitúrico (TBARS), hidroperóxidos (HP) e dienos conjugados (CD). Foi avaliado a atividade antioxidante do isotiocianato de moringa (MIC-1) purificado do extraído da semente da MO, exercida pela estimulação do Nuclear factor erythroid 2-related factor 2 (Nrf2) no contexto da nefropatia diabética (DN), em células in vitro.…”