Antidiabetic potential of bioactive extracts from fruits and vegetables: A review

Diabetes mellitus is a condition in which glucose levels in the blood are much higher than normal and hence this condition is also commonly referred as sugar disease (hyperglycaemia). The defect in this condition is that either the pancreas does not produce enough insulin or it produces sufficient insulin, but the cells of the body are unable to use the insulin properly. Insulin is a chemical (a hormone) made in a part of the body called the pancreas. Insulin helps the glucose get into your cells from food. Diabetes is diagnosed by blood sugar (glucose) testing. Types of diabetes; Type 1 diabetes is sometimes called insulin-dependent, immune-mediated or juvenile-onset diabetes. Type 2 diabetes is sometimes called non-insulin dependent diabetes or adult-onset diabetes, and accounts for at least 90% of all cases of diabetes. Bioactive extracts from fruits and vegetables may recover the disorder in carbohydrate metabolism noted in diabetic state by protecting the oxidative stress induced tissue damage for such disorder and or by stimulating the carbohydrate regulatory enzyme activities in target organ and/or stimulate or regenerating β cells in pancreas. Administration of aqueous extract of pulp of S. cumini and bark of C. zeylanicum in composite manner exhibited better antidiabetic activity than when compared to the individual extract of the plants. Administration of composite extract of E. jambolana and M. paradisiaca is more effective than individual extract to challenge the diabetic state. Methanolic and aqueous extracts of Terminalia catappa fruit exhibited significant antihyperglycemic activities in alloxan-induced diabetic rats. A water extract of Momordica charantia powder at doses as low as 20 mg/kg body weight can reverse alloxan induced hyperglycemia in rats with no toxicity to liver and kidneys up to a period of 4 weeks. Ethanolic extract of Terminalia chebula fruit has potential hypoglycemic action in streptozotocin (STZ) induced diabetic rats and the effect was found to be more effective than glibenclamide (a standard diabetic drug). The advantage of this natural preparation lies in its ability not only to control hyperglycemia at low dosages but can also be taken for longer periods.