Toxicological evaluation of the effect of African cat fish (Clarius gariepinus) from water contaminated with biodiesel on the liver of Albino rats

This study investigated the effect of African cat fish (Clarias gariepinus) from water contaminated with biodiesel on the liver of albino rats. The Biodiesel from PKO was diluted with distilledwater to obtain 0.25 and 0.1 %v/v. Twenty-four healthy juvenile catfish (Clarias gariepinus) were obtained from a commercial fish pond and acclimatized for ten days prior to the commencement of the experiment. The catfish were grouped into three (3) of eight catfish and were kept in 30L plastic aquaria. Group A served as control and the catfish here were cultured in distilled water while those in Groups B and C were exposed to the different mixtures (0.1%v/v and 0.25% v/v respectively) of Biodiesel from PKO. The catfish were fed ad libitum with commercial fish meal for 30hrs during which the experiment lasted. At the end of the 30 h experimental period, the catfish were harvested, oven dried at 40oC and used as a source ofprotein (25%) to formulate diet for albino rats. The diet for each group was formulated by mixing known quantities of sources of each food class comprising corn starch (52%), oil (4%), maize cob (4%), sucrose (10%) and vitamin/mineral mixture (5%). Generally, it was observed that concentrations of direct and total bilirubin of rats increased significantly (p<0.05) as the level of biodiesel increased while the serum concentrations of albumin and globulin decreased significantly (p<0.05) with increasing level of biodiesel. There was no significant difference (p>0.05) between the concentration of serum total bilirubin of BD0.1 rats and the control, while that of BD0.25 rats was significantly higher than that of control (p<0.05). Specific activities of alanine transaminase (ALT), asparatate transaminase (AST) and Gama glutamyl transpeptidase (GGT) of serum of BD0.1 and BD0.25 rats were not significantly different(p>0.05) but significantly lower than those of control rats. Elevated serum bilirubin of rats observed in this study suggested liver dysfunction which may not be unconnected with catfish exposed to biodiesel from PKO. Abnormal values of serum GGT, ALT and AST also indicatedthat the catfish exposed to PKO biodiesel might have altered protein metabolism, among others, at the subcellular level and this may be indicative of impairment of the function of the tissues. The observed decreased activity of SOD, CAT and GST in the liver of rats fed with catfish exposed to PKO biodiesel was indicative of oxidative stress.