A Study of Some Effects of Aqueous Extract of Neem (Azadirachta Indica) Leaves on the Lead Acetate Induced Neurotoxicity in the Superficial Layers of Superior Colliculus of Adult Wistar Rats (Rattus norvegicus)

Aim: To investigate some neuroprotective effects of aqueous extract of Neem leaves against damaging actions of lead acetate induced neurotoxicity in the superficial layers of the superior colliculus of adult wistar rats.
Study Design: Histological and Biochemical study.
Place and Duration of study: Department of Anatomy, Faculty of Basic Medical Sciences, LAUTECH, Nigeria between January 2012 and August 2012.
Methodology: 40 adult wistar rats (average weight 200±16.2g) were randomly assigned into 4 groups (N=10) of Control C, Treatments T1, T2 and T3 and treated with distilled water, 1% lead acetate and 200mg/kg b.wt of aqueous extract of neem, 1% lead acetate, and 200 mg/kg b.wt of aqueous extract of neem respectively for14days.They were sacrificed by cervical dislocation and processed for routine histopathological studies, bioassay of some antioxidant parameters as well as lipid peroxidation.
Results: Statistically significant (P=0.05) body weight, wet brain weight as well as neuronal cell loss was recorded in T2 while T1 and T3 showed statistically insignificant weight loss compared to control. Oxidative stress enzymes Superoxide dismutase, Glutathione reductase and Glutathione peroxidase levels were significantly (P=0.05) reduced in T2 compared to the control but relatively increased in T1 and T3. T3 and T1 respectively recorded 65% and 55% increments above T2 in Glutathion levels while Lipid peroxidation level was drastically reduced in T3 and to some extent in T1 compared to increased level in T2. Group T2 showed sparsely distributed pyknotic pyramidal neurons with obliterated soma and few glial cells while T1 sections appeared less distorted. Neem offers some ameliorative protection to the pyramidal neuronal and glial cells of the superficial layers of the superior colliculus against lead compared to T2, however the control and T3 sections relatively appeared normal.
Conclusion: Neem offers ameliorative protection to the pyramidal neuronal and glial cells of the superficial layers of the superior colliculus against lead acetate induced neurotoxicity in wistar rats and also further affirms its antioxidative potential.