Ethanol extract of mango (Mangifera indica L.) peel inhibits α-amylase and α-glucosidase activities, and ameliorates diabetes related biochemical parameters in streptozotocin (STZ)-induced diabetic rats

Abstract

Peel is a major by-product during processing of mango fruit into pulp. Recent report indicates that the whole peel powder ameliorated diabetes. In the present study, ethanolic extract of mango peel was analysed for its bioactive compounds, evaluated for α-amylase and α-glucosidase inhibitory properties, oral glucose tolerance test, antioxidant properties, plasma insulin level and biochemical parameters related to diabetes. In addition to gallic and protocatechuic acids, the extract also had chlorogenic and ferulic acids, which were not reported earlier in mango peel extracts. The peel extract inhibited α-amylase and α-glucosidase activities, with IC50 values of 4.0 and 3.5 μg/ml. Ethanolic extract of peel showed better glucose utilization in oral glucose tolerance test. Treatment of streptozotocin-induced diabetic rats with the extract decreased fasting blood glucose, fructosamine and glycated hemoglobin levels, and increased plasma insulin level. Peel extract treatment decreased malondialdehyde level, but increased the activities of antioxidant enzymes significantly in liver and kidney compared to diabetic rats. These beneficial effects were comparable to metformin, but better than gallic acid treated diabetic rats. The beneficial effects of peel extract may be through different mechanism like increased plasma insulin levels, decreased oxidative stress and inhibition of carbohydrate hydrolyzing enzyme activities by its bioactive compounds. Thus, results suggest that the peel extract can be a potential source of nutraceutical or can be used in functional foods and this is the first report on antidiabetic properties of mango peel extract.

Glycosylated flavonoids: fruit's concealed antifungal arsenal

“…Concomitantly, red mango fruit with enhanced anthocyanin and flavonoid contents show improved resistance to fungal pathogens and better cold tolerance (Sivankalyani et al, 2016b;Sudheeran et al, 2018). Previous studies have shown that extracts of M. indica possess a variety of compounds, including proteins, carbohydrates, minerals, phenolic compounds and dietary fiber (Gondi & Rao, 2015), which has antiviral and antibacterial activities (Makare et al, 2001). Previous studies have shown that extracts of M. indica possess a variety of compounds, including proteins, carbohydrates, minerals, phenolic compounds and dietary fiber (Gondi & Rao, 2015), which has antiviral and antibacterial activities (Makare et al, 2001).…”

Mango and diabetes

“…Mango peel, leaves, and mango kernel flour have been used to modulate glycemia in animal models, but are not part of South Asian diet. [8][9][10]…”

Multifaceted Healthy Benefits of <em>Mangifera Indica</em> L. (Mango): The Inestimable Value of an Orchard Recently Rooted in Sicilian Rural Areas

“…Pulp and leaf extracts of mango produced a significant hypoglycemic effect in streptozotocin (STZ)-induced diabetic rats [25][26][27]. Furthermore, Gondi et al [28] showed that also mango peel extracts have the ability to ameliorate diabetes. In fact, administration of different doses of peel extracts to STZ-induced diabetic rats resulted in significant decline in blood glucose levels, increased plasma insulin level as well as decreased levels of fructosamine and glycated hemoglobin, two diabetes status indicators.…”

“…The anti-diabetic effect of mango peel extracts can be partially attributed to their ability to inhibit α-amylase and α-glucosidase, the carbohydrate hydrolyzing enzymes. This effect may be due to the presence of polyphenolic acids, like gallic acid, chlorogenic acid and ferulic acid, which have been shown to inhibit α-amylase and α-glucosidase activities [28]. Subclinical low-grade inflammation plays an important role in the pathogenesis of insulin resistance.…”