Memory state and hippocampal histomorphology in Wistar rat following monosodium glutamate-induced neurotoxicity; role of aqueous extract of Aloe Barbadensis

This study assessed the effect of varying doses of aqueous extract of Aloe barbadensis on the cellular changes of hippocampal cells, oxidative and memory state of Wistar rats following monosodium glutamate-induced neurotoxicity. Eighty Wistar rats (8 weeks) were randomly assigned into 4 groups of 20 rats; Group 1 received 3 mL/kg of distilled water. Groups 2, 3 and 4 received 3 g/kg/day of MSG. In addition, groups 3 and 4 received 100 and 200 mg/kg/day of AB extract respectively. Administration was done orally for 28 days in all groups. Five rats per group were sacrificed weekly over a 4-week period. Memory was assessed using radial arm maze on the last day of administration. Following brain harvest, one cerebral hemisphere was homogenized for oxidative state assessment, while the other was fixed in 10% neutral buffered formalin and stained with H&E for hippocampal histomorphology. Data obtained were analyzed using student t-test and p value < 0.05 was considered significant. Across the 4-week period, group 2 rats showed significant increase in time spent to identify baited arms, significant reduction in density of apparently normal neurons and oligodendrocyte in CA 1-3 regions of hippocampus, and significant increase in reduced glutathione when compared with other groups. However, no significant differences were noted between groups 1, 3 and 4 for the above stated parameters. The study concluded that MSG caused hippocampal neuronal and oligodendrocytes degeneration and impairment of memory. These anomalies are prevented by 100 and 200 mg/kg of Aloe barbadensis.