Effects of Aqueous Leave Extracts of Launaea taraxacifolia (Willd.) on the Hippocampal Damage in Streptozotocin-Induced Diabetic Wistar Rats

Abstract

This study determined the anti-diabetic effects, assessed the antidepressant properties, and investigated the ameliorative effects of aqueous leaf extract of Launaea taraxacifolia (ALELT) on streptozotocin (STZ)-induced diabetic rats. It also evaluated its antioxidant effects on oxidative stress markers in diabetic rats. Forty-two male Wistar rats (110-130 g) were divided into seven groups (A, B, C, D, E, F, and G) of six animals each. Group A was the control, while STZ solution (80 mg/kg) was administered IP to diabetic groups B, C, D, E, and F. At the sixth week of induction, group B was the STZ control; groups C, D, and E rats received 300 mg/kg, 200 mg/kg, and 100 mg/kg per oral (p-o) of ALELT, respectively, for three weeks. Group F received 5 IU/day of insulin subcutaneously; group G received only 300 mg/kg p-o of ALELT for three weeks. After the study, the animals were sacrificed; the hippocampus was excised and fixed in a 10% neutral buffer solution for morphometric analysis. Homogenized samples were used to determine oxidative stress markers, brain derived neurotrophin factor (BDNF) level and insulin concentrations. The results showed varying degrees of hippocampal damage and loss of hilum of Dentate gyrus in the H&E sections, plaque and tangles in the Bielschowsky sections, loss of myelin sheath in the Luxol Fast Blue sections, and dissolution of Nissl bodies in the Cresyl Fast Violet sections, followed by weight loss, abnormal rise in glucose levels, decrease in BDNF, decrease in insulin levels, memory loss in neurobehavioral tests, and decrease in markers of oxidative stress in the negative control rats. These pathologies were reversed in the extract-treated groups and the results were comparable with group A. This study concluded that ALELT demonstrated anti-diabetic effects, mediated by the reduction of fasting blood sugar levels, increased insulin secretion, and elevated BDNF in the hippocampus of diabetic Wistar rat.