RESUMO
Background: Automobile repair workshops contribute immensely to the generation of soil and water contamination. This study was conducted to compare the soil microbial load, heavy metals, and consequent toxicological effects, in three (3) automobile mechanic sites. Method: Soil samples were randomly collected from 3 different auto mechanic workshop in Abeokuta town of Ogun-State, Nigeria. Bacterial and fungal counts were done via standard procedures. High-performance liquid chromatography was employed for the aflatoxin quantification. Also, 24 Wistar rats were divided into 4 groups (n = 6), group 1-Control animals: orally administered distilled water, Group 2-administered soil sample solution from Ita Oshin mechanic site (I M), Group 3-administered soil sample solution from Ajebo mechanic site (A M), while Group 4-administered soil sample solution from Laderin mechanic site (L M), for two (2) weeks. Conventional methods were used to determine some physical and biochemical parameters in the rat's serum and tissues. Results: Eight bacterial and fungal genera were identified from the soil samples with Bacillus subtilis and Aspergillus niger occurring most frequently. The levels of heavy metals (lead, zinc, chromium, and cadmium) analyzed were higher than the WHO permissible heavy metal limits in all samples. The activity of liver function enzymes ALP, AST, and ALT was significantly increased in the serum of animals exposed to the 3 soil solution samples when compared with the control group, with the highest recorded at Site II. Conclusion: High level of heavy metals and aflatoxins could predispose to several health-related hazards when humans are exposed to contaminated soil solutions around and within automobile mechanic areas.
RESUMO
BACKGROUND: Sodium benzoate (SB) is a widely used food preservative. However, excessive intake of a high dose of SB poses a risk of neurotoxicity. Ascorbic acid (AA) is a naturally occurring antioxidant found in fruits with reported neuroprotective properties. The present study investigated the neurobehavioral and biochemical alterations in SB-treated rats and the ameliorative effect of AA in rats. METHODS: Forty-two male Wistar rats were divided into six groups (n = 7). Group 1 (vehicle, 10 ml/kg), Groups 2-4 rats SB (150, 300, and 600 mg/kg), Group 5 AA (100 mg/kg) and Group 6 (SB 600 mg/kg + AA 100 mg/kg). Treatment was daily administered for 28 days by oral route. Anxiogenic behavior, locomotor, and exploratory activities were evaluated in the open field monitored with a camera, and memory performance in Y-maze. Brain oxidative stress, inflammatory, apoptosis, and cholinergic markers were determined. The cortico-hippocampal tissues were examined histologically. RESULTS: SB-treated rats showed significant anxiogenic-like behavior and impairment in locomotor, exploratory, and memory performance. This was reversed in SB (600 mg/kg)-treated rats coadministered with AA. SB-treated rats showed a decrease in antioxidant enzyme activities, increase malondialdehyde (MDA), nitrite, tumor necrosis factor-alpha, caspase-3, and acetylcholinesterase activity in the striatum, hippocampus, frontal cortex, and cerebellum. These biochemical changes were reversed in AA-treated rats. Reduced cortico-hippocampal neuronal cell count and the pyknotic index were found in SB-treated rats, which was also reversed in AA-treated rats. CONCLUSION: Conclusively, sodium-benzoate-induced neurobehavioral deficits and brain biochemical changes were ameliorated by ascorbic acid probably via antioxidant, anti-inflammatory, and apoptotic mechanisms.