Neuronal cell membrane protective effects of Combretum micranthum methanol leaf extract on lead-induced brain damage in Swiss albino mice

Abstract

Combretum micranthum is used traditionally for many therapeutic purposes such as fatigue, liver ailments, headache, convalescence, blood disease, weight loss among others. Studies suggested that free radical production may be one main reason behind stress induces neurochemical changes that include neurotransmitter imbalance and histopathological alterations in the brain cell. Thus this study examined the relationship between brain histopathological alterations and neurotransmitter imbalance (gamma aminobutyric acid - GABA) in lead exposure, and possible neuroprotective role of Combretum micranthum  methanol leaf extract in mice. Thirty six (36) Swiss Albino mice (19 - 22g body weight) were used for the study, randomized equally into six groups and treated for the period 14days:  a) Normal Control (Distilled water), b) Negative control (40 mg/kg lead acetate), c) lead acetate + 100 mg/kg b.w. extract, d) lead acetate + 50 mg/kg b.w. extract,  e) lead acetate + 25 mg/kg b.w. extract and f) positive control (lead acetate + diazepam 0.5 mg/kg b.w). The study assayed for protective potential of Combretum micranthum on neuronal cell membrane through determination of the brain cells malondialdyhyde (MDA) levels, morphology and GABA levels. Result of the study showed a significantly increase level of GABA in the brain of mice administered doses of the extract with a decreased level of MDA, as compared to those mice treated with 40 mg/kg lead acetate alone, which showed decreased level in GABA (310.83pg/ml), but an increased level of MDA (30.03μmolTBARS/mg). Also the mice administered doses of the extract showed normal neurons while intensive neuronal necrosis was observed on those mice treated with 40mg/kg lead acetate alone. However, mice administered with the doses of the extract shows no any significant difference with those in the normal control and positive control treatment groups.  Also the Combretum micranthum  methanol leaf extract was found, using GC-MS, to contain propargylamine, a compound known to possess anti-apoptosis functions, and also those with GABAergic functions 3,4-dichlorophenylhydrazine, guanidine and aminooxyacetic acid. Findings of the present study has proven Combretum micranthum to be a potential plant in managing and preventing brain structural damage induced by lead administration.

Keywords: Lead, Combretum micranthum, GABA, malondialdyhyde (MDA) and histopathology