Antioxidant, hypoglycemic and hypolipidemic effects of selected African indigenous medicinal plants in a type 2 diabetes model of rats.

Abstract

The study investigated the antioxidant, antidiabetic, and anti-obesity activities of selected traditional medicinal plants, including Rhus longipes, Celtis africana, Schotia brachypetala, Trema orientalis, and Albizia adentifolia, through in vitro, ex vivo, in silico, and in vivo models using rats. Bioactive compounds in the dry stem bark and leaves of the plants were extracted by serial maceration in water, methanol, ethanol, and ethyl acetate, followed by quantification and identification using gas chromatography-mass spectrometry (GC-MS). In vitro models assessed the extracts’ electron donation, free radical scavenging, and lipid and carbohydrate digestive enzyme inhibition capabilities. Ex vivo models were used to investigate the extracts abilities to mitigate FeSO4-induced oxidative injury in excised heart, liver, pancreas, kidney, and brain tissues. Furthermore, the extracts' effects on glucose uptake in rat muscle and liver, and sugar absorption in the rat jejunum, were also studied. Molecular docking in silico analysed the binding affinities and interactions of the identified compounds with diabetes-related proteins. The biological activities of extracts showing significant antidiabetic activity (Rhus longipes, Celtis africana, and Schotia brachypetala) in vitro, in silico, and ex vivo were further investigated using model rats with type 2 diabetes in vivo. The results showed that the plant extracts contained a variety of bioactive compounds which may have contributed to their enhanced antioxidant and digestive enzyme inhibitory capabilities. The extracts demonstrated hypoglycaemic potential by modulating glucogenic enzymes, increasing glucose uptake in psoas and liver tissues, and retarding intestinal glucose absorption. The extracts exhibited protective effects against oxidative imbalance in isolated rat tissues by inhibiting lipid peroxidation and augmenting the activity of intrinsic antioxidant enzymes. The in vivo results demonstrated that extracts abated redox imbalance, restored euglycemic levels, mitigated dysregulated lipid metabolism, reversed pancreatic β-cells tissue damage, and linked biochemical parameters to homeostatic levels in treated animals compared with those in the untreated diabetic group. The results of this study revealed the potential of selected plant extracts to ameliorate type 2 diabetes and its associated complications. Further molecular analyses and clinical trials are necessary to elucidate the precise mechanisms of antidiabetic action demonstrated in this study.