Virgin coconut oil attenuates cognitive dysfunction and oxidative stress in streptozotocin-induced diabetic rats

Abstract

Hyperglycemia contributes to neuronal damage and cognitive impairment. Although virgin coconut oil (COL) is traditionally used to enhance memory, its neuroprotective mechanisms remain inadequately understood. This study investigates the fasting blood glucose (FBG)-lowering and neuroprotective effects of COL in streptozotocin (STZ)-induced diabetic rats. Adult Wistar rats were trained for memory tasks and rendered diabetic with STZ (45 mg/kg, intraperitoneal injection). Seventy-two hours post-induction, rats with FBG levels exceeding 250 mg/dL were assigned to five groups: control, untreated diabetic, metformin-treated diabetic, and diabetic rats treated with COL (0.5 or 1.0 mL/kg body weight). FBG was monitored on days 1, 7, and 14, and spontaneous escape latency (SEL) was assessed. Brain and other tissues were homogenized and analyzed for biochemical and antioxidant markers. Untreated diabetic rats exhibited significantly (p < 0.05) elevated FBG and prolonged SEL, indicating impaired glycemic control and memory performance. Treatment with metformin or COL markedly reduced FBG and improved SEL. Untreated diabetic rats showed increased α-amylase, α-glucosidase, cholinesterase, monoamine oxidase, and arginase activities with reduced antioxidant enzyme levels. Meanwhile, COL treatment reversed these alterations, enhancing antioxidant defense and modulating key metabolic enzymes. COL demonstrated significant antihyperglycemic and neuroprotective effects, suggesting its therapeutic potential in mitigating diabetes-induced oxidative stress and memory dysfunction.