Inhibitory effect of aqueous extracts of some citrus peels on key enzymes linked with type-2 diabetes and some pro-oxidant induced lipid peroxidation in rats pancreas invitro.

摘要

Ability of aqueous extracts from citrus peels, namely orange (Citrus sinensis), grapefruit (C. paradisii) and shaddock (C. maxima) to inhibit key enzymes linked to type 2 diabetes (T2D) in vitro was investigated. Studies were done by assessing 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) radical scavenging ability and the ferric-reducing antioxidant property of the extracts, as well as their ability to inhibit Fe2+- and sodium nitroprusside-induced lipid peroxidation in rat pancreas and to inhibit alpha-amylase and alpha-glucosidase activity in vitro. Orange peels had higher total phenol (8.33 mg/g) and flavonoid (0.58 mg/g) contents than grapefruit (6.50 and 0.29 mg/g) and shaddock (5.00 and 0.15 mg/g). Orange peel aqueous extracts also showed highest antioxidative activity. The extracts inhibited beta-glucosidase and alpha-amylase activities, but inhibition of beta-glucosidase was stronger (orange 37.50%, grapefruit 50.0%, shaddock 37.50%) than that of alpha-amylase (orange 25.32%, grapefruit 29.29%, shaddock 21.34%). Results suggest that the tested peel extracts could be used to control blood glucose levels associated with T2D.