Protective nature of mangiferin on oxidative stress and antioxidant status in tissues of streptozotocin-induced diabetic rats

Oxidative stress plays an important role in the progression of diabetes complications. The aim of the present study was to investigate the beneficial effect of oral administration of mangiferin in streptozotocin (STZ)-induced diabetic rats by measuring the oxidative indicators in liver and kidney as well as the ameliorative properties. Administration of mangiferin to diabetic rats significantly decreased blood glucose and increased plasma insulin levels. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) and level of reduced glutathione (GSH) were significantly (P < 0.05) decreased while increases in the levels of lipidperoxidation (LPO) markers were observed in liver and kidney tissues of diabetic control rats as compared to normal control rats. Oral treatment with mangiferin (40 mg/kg b.wt/day) for a period of 30 days showed significant ameliorative effects on all the biochemical and oxidative parameters studied. Diabetic rats treated with mangiferin restored almost normal architecture of liver and kidney tissues, which was confirmed by histopathological examination. These results indicated that mangiferin has potential ameliorative effects in addition to its antidiabetic effect in experimentally induced diabetic rats

Mangiferin from Salacia chinensis prevents oxidative stress and protects pancreatic β-cells in streptozotocin-induced diabetic rats

Oxidative stress in diabetic tissues is a consequence of free radical accumulation with concurrently impaired natural antioxidants status and results in oxidative tissue damage. The present study investigated the protective effects of mangiferin against pancreatic β-cell damage and on the antioxidant defense systems in streptozotocin (STZ)-induced diabetic rats. Diabetes was experimentally induced by a single intraperitoneal injection of STZ. Oxidative stress biomarkers such as tissue malondialdehyde, hydroperoxides, reduced glutathione (GSH) content, and nonenzymatic antioxidants were measured. Biochemical observations were further substantiated with histological examination and ultrastructural studies in the pancreas of diabetic, glibenclamide and mangiferin-treated diabetic rats (dosage of 40 mg/kg body weight daily for 30 days). Oral administration of mangiferin and glibenclamide to diabetic rats significantly decreased the level of blood glucose and increased levels of insulin. Additionally, mangiferin treatment significantly modulated the pancreatic nonenzymatic antioxidants status (vitamin C, vitamin E, ceruloplasmin, and reduced GSH content) and other oxidative stress biomarkers. The histoarchitecture of diabetic rats showed degenerated pancreas with lower β-cell counts, but mangiferin treatment effectively regenerated insulin secreting islet cells. The electron microscopic study revealed damaged nuclear envelope and mitochondria and fewer secretory granules in pancreas of diabetic rats; however, mangiferin treatment nearly normalized pancreatic architecture. The present findings suggest that mangiferin treatment exerts a therapeutic protective nature in diabetes by decreasing oxidative stress and protecting against pancreatic β-cell damage, which may be attributable to its antioxidative properties

Comparison of the Contents of Bioactive Compounds and Quality Parameters in Selected Mango Cultivars

Mango cultivars Tommy Atkins, Zill, Peach, Sabre, Rosa and Phiva were analyzed for their quality parameters (fruit weight, flesh color chroma, L, h0, total soluble solid [TSS]/titratable acidity [TA], firmness), bioactive compounds (total phenols, carotenoids, ascorbic acid, antioxidant activity) and polyphenol oxidase (PPO) activity. Cv. Sabre showed highest total phenolic content (76.43 mg gallic acid/100 g FW), carotenoids (9.90 mg/100 g of FW), ascorbic acid content (69.71 mg/100 g of FW) and antioxidant activity (1.2 mg of gallic acid/g of FW), whereas cv. Peach mango contained lower bioactive compounds. Multivariate principal component analysis analysis showed higher concentration of bioactive compounds in cv. Sabre mango, whereas cv. Tommy Atkins was firm and heavier. Cv. Rosa and Phiva were moderately rich in bioactive compounds and lower in fruit weight and firmness, whereas cv. Peach was higher in TSS/ TA. The PPO activity was higher in cvs. Rosa and Zill.Instituto de Tecnología de AlimentosFil: Sellamuthu, Periyar Selvam. Tshwane University of Technology. Department of Crop Science. Postharvest Technology Group; SudáfricaFil: Denoya, Gabriela Inés. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimento. Laboratorio de Compuestos Proteicos; ArgentinaFil: Sivakumar, Dharini. Tshwane University of Technology. Department of Crop Science. Postharvest Technology Group; SudáfricaFil: Polenta, Gustavo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Tecnología de Alimento. Laboratorio de Compuestos Proteicos; ArgentinaFil: Soundy, Puffy. Tshwane University of Technology. Department of Crop Science. Postharvest Technology Group; Sudáfric