Bonny Light Crude Oil Toxicity: Histopathological and Biochemical Upshots on Cardiac and Hepatocellular Tissues

Aim: Evaluate the acute toxicity effect of bonny light crude oil on histopathological and biochemical disrupting effects on cardiac and hepatocellular tissues. Oil spills, gas flaring, natural seeps, industrial discharge, and the destruction of ecosystems have led to ecological devastation, health problems, and socioeconomic challenges for communities in the Niger Delta; one of the world's largest oil-producing regions. Crude oil spillage has been a persistent and severe environmental concern in the Niger Delta for many years. The spilled oil covers water surfaces, diminishes oxygen levels, and poses significant health risks to aquatic life, birds, loss of biodiversity, and the well-being of the human population that heavily relies on these resources for their sustenance.

Study Design: A total of 50 albino rats were randomly divided into three (3) groups; control group, low dose group, and high dose group. The control group consisted of 10 albino rats while the low dose and high dose groups consisted of 20 albino rats each. The control group was fed with normal (uncontaminated) rat feeds and sterile water only (that is, a dosage of 0.00mL/g of rat feed), and the low dose (0.005mL/g) group was fed with 300g of rat feeds mixed with 1.5mL of BLCO while high dose (0.01mL/g) group was fed with 300g of feeds mixed with 3.0mL of BLCO. The treated feeds were administered once every day for 35 days.

Methodology: After day 35, the rats were allowed to fast overnight and anesthetized with chloroform (CHCl3). Blood specimens (5 ml) were collected by slitting the neck of the rats into an anticoagulant labeled bottle. The livers and hearts of the experimental rats were harvested and preserved in 10% formalin in different labeled plastic containers prior to tissue processing and histological examinations. Blood specimens were centrifuged at 4500 rpm for 10 minutes to obtain plasma. Plasma levels of ALT, AST, ALP, cTnT, cTnI, MDA, and SOD were estimated. All weights were measured in grams.

Results: The result indicated that low and high-dose treated groups showed a significant decrease in body weight. The SOD and MDA indicated significantly lower and higher values respectively in the low and high-dose treated groups when compared to the control rats. However, no significant difference in SOD values was seen between the low and high dose treated groups. The ALT, AST, and ALP values indicated significantly higher values in the low and high-dose treated groups compared to the control group. More so, dose-dependent increases were also observed in AST and ALT. However, ALP indicated no significant difference between the control and the low-dose treated rats. In addition, cTnT and cTnI values indicated significantly higher values in the low and high-dose treated groups compared to the control group. However, cTnT and cTnI indicated no significant difference between the high-dose and the low-dose treated rats. The P value was set to P=.05

Conclusion: Bonny light crude oil in feed at small doses over a period of 35 days induced myocardial and hepatic injuries indicated by increased levels of AST, ALT, ALP, cTn-T, and cTn-I. More so, histopathological changes further showed the disrupting changes in hepatic and cardiac tissues.