NEUROPROTECTIVE EFFECT OF THE LEAF EXTRACT AND FRACTIONS OF AFRICAN EGG PLANT (SOLANUM DASYPHYLLUM) AGAINST CYANIDE-INDUCED NEUROTOXICITY

Abstract

Solanum dasyphyllum is known to have anticonvulsant, neuromodulatory and cardiovascular (hypotensive) properties. In this study, Solanum dasyphyllum extract and fractions were investigated for the protective effect on cyanide-induced neurotoxicity. The leaves extract of Solanum dasyphyllum (CRUDE) as well as various fractions n-hexane (HSFD), dichloromethane (DFSD), ethylaceate (EAFSD) and methanol (MFSD) were obtained and screened for various phytochemicals. Two regions of the rats brain (cortex and cerebellum) homogenates were incubated with potassium cyanide (KCN) with varying concentrations (5, 10, 20, 30, 40 and 50 μg/ml) of S. dasyphyllum extract and fractions for 1 hour at 37 oC. Acetylcholinesterase activity, mitochondrial enzymes activities (NADH-cytochrome c reductase (NCCR), succinate-cytochrome c reductase (SCCR) and NADH-succinate dehydrogenase (NSDH)), levels of reduced glutathione, protein carbonyl, and lipid peroxidation were assayed for. The phytochemical screening of S. dasyphyllum leaf extract revealed the presence of alkaloids, flavonoids, terpenoids, cardiac glycosides, saponins, tannins and steroids. Also KCN increased acetylcholinesterase (AchE) activities compared to the control group (P<0.05). Methanolic fraction at 20 μg/ml (1.07±0.16) and 30 μg/ml (0.06±0.015) exhibited the highest anticholinesterase activity in the cortex and cerebellum respectively. Also, the mitochondrial enzyme activities were compromised by KCN intoxication and were significantly ameliorated by various fractions of S. dasyphyllum both in the cortex and cerebellum. Levels of GSH and LPO were significantly reduced and increased by KCN intoxication, respectively. Fractions of S. dasyphyllum ameliorated the reduction and elevation in GSH and LPO, respectively. The highest level of GSH was observed in n-hexane fraction at 40μg/ml (0.57±0.031) and at 30μg/ml (0.58±0.054) in the cortex and cerebellum respectively, and the reduction of LPO was best observed at 50 μg/ml for methanolic fraction (03.65±0.188) and (07.31±0.610) for both the cortex and cerebellum respectively. These results show that S. dasyphyllum extract and fractions possessed brain health-promoting property and may be effective in the management of toxicant –induced neurologic disorders.