TOXICOLOGICAL EFFECTS OF Clarias gariepinus EXPOSED TO AQUEOUS AND ETHANOIC EXTRACTS OF Azadiractha indica
Abstract
The use of biomarkers for monitoring both the condition of organisms and environmental quality especial fish has received attention in recent years. Exposure of aquatic organisms to bioassay test various plant extracts have been shown to have detrimental effects on them thereby resulting in their death. Toxicological investigations were carried out to determine the lethal, sub-lethal concentration, the biochemical parameters and histopathological response of the exposed organisms to Aqueous and Ethanoic extracts of Azadiractha indica. One way ANOVA was used to determine levels of significance (P < 0.05). The physic-chemical parameters of Aqueous and Ethanoic extracts were carried out. The 96 hrs LC50 value for C. gariepinus exposed to Azadiractha indica were 9.930 g/L for ethanol and aqueous extract respectively. Analysis of Variance (ANOVA) showed that there was significant difference (p<0.05) in the quantal response at 24, 48, 72, 96th of exposure. Alanine Aminotransaminase (ALT), Aspartate Aminotransaninase (AST), Alkaline Phosphatase (ALP) and Total Protein (TP) were significantly different, (P < 0.05) and increased compared to control group during the exposure to aqueous and ethanol extracts of Azadiractha indica. The results for the histopathology over a period of 28 days shows no inflammation or pathology on the gills, kidney and liver of C. gariepinus exposed to both aqueous and ethanol extract of Azadiractha indica at lower concentration (5, 5.5 and 6 g/L). At higher concentration (7.5 and 8 g/L), there was dense inflammatory infiltrate within the interstitium of the kidney. Destruction of respiratory epithelium of the gills and vacuoles within the hepatocytes with areas of necrosis for the liver. This study showed that exposure to higher doses of bth aqueous and ethanol extract of Azadiractha indica had negative effect on C. gariepinus, following the biochemical response and histopathology composition. This study is valuable for fish famers to know the treatment concentration that can prove the use of Azadiractha indica as anti-stressors.
