Begonia cucullata Extracts Present Antidiabetic Potential by Protecting Human Endothelial Cells and Rats from Oxidative Damage Induced by Glucose Overload.

Diabetes mellitus (DM) is a disease characterized by issues in insulin metabolism and consequent hyperglycemia, associated with oxidative stress and endothelial dysfunction. Current pharmacotherapy for DM is not fully effective, as complications continue even after glycemic control. Thus, plants rich in bioactive compounds with antioxidant potential may be valuable in DM management. Begonia cucullata is a non-conventional edible plant rich in phenolic compounds and traditionally used in medicine as an anti-diabetic agent. However, pharmacological studies on this plant are scarce. This study evaluated the antidiabetic potential of B. cucullata flowers (BFE) and leaves (BLE) extracts in human endothelial cells and rats. Endothelial cells were cultivated in normal (25mM) or high (35mM) glucose and exposed to BFE or BLE (1-100 µg/mL) for 24 h. Healthy and streptozotocin-induced diabetic rats received BFE (200 mg/kg) orally for 4 weeks. HPLC analyses of extracts revealed gallic acid, catechin, epigallocatechin gallate, epicatechin, and epigallocatechin in BFE, whereas BLE exhibited epigallocatechin and myricetin. Both extracts displayed antioxidant activity in vitro and were able to protect cells against oxidative damage caused by glucose overload. BFE attenuated oxidative stress and decreased triglyceride levels in diabetic rats, besides being not hepatotoxic or nephrotoxic. The data suggests that B. cucullata extracts may be potential adjuncts in DM therapy by exerting antioxidant effects and improving triglyceride levels.