Supplementation of Mango (Mangifera indicaL.) Peel in Diet Ameliorates Cataract in Streptozotocin-Induced Diabetic Rats

Abstract

Cataract is a secondary complication of diabetes and consumption of diet rich in antioxidants and dietary fiber exerts beneficial effects. The effect of mango peel on delay in progression of cataract was evaluated in streptozotocin-induced diabetic rats. Diets supplemented with mango peel at 5 and 10% levels ameliorated cataract formation. On treatment of diabetic rats with peel for 16 weeks, lens soluble protein content, glutathione levels and antioxidant enzyme activities were increased by 1.5–2.5 fold while lipid peroxidation and protein carbonyl levels as well as advanced glycation end products formation in lens proteins of diabetic rats were significantly decreased. Mango peel supplementation also inhibited polyol pathway enzyme activities in diabetic rats. Thus, mango peel was effective against development of diabetic cataract mainly through augmentation of antioxidant levels, inhibition of polyol pathway enzymes and AGEs formation in lens of diabetic rats. PRACTICAL APPLICATIONS Oxidative damage to the constituents of eye lens is considered to be the major mechanism for development of various types of cataract and intake of food rich in antioxidants has been reported to delay progression of cataract. Mango peel is a by-product of mango pulp processing industry and is rich in antioxidants and exhibits antidiabetic properties. This study found that mango peel supplemented diet delayed the progression of diabetic cataract formation. Thus, mango peel can be supplemented in foods for management of diabetes and its complications.