Biochemical and Genotoxic Markers in Lumbricus terrestris as Indicators of Crude Oil Pollution in Kolo Creek, Niger Delta, Nigeria

Abstract

This study evaluates biochemical and genotoxic markers in Lumbricus terrestris (LT) harvested from Kolo Creek, Bayelsa State, Nigeria. Three sites (A – Imiringi I; B – Imiringi II (with the presence of oil wells and exploration activities) and C – Emeyal (no exploration activity) were used for this research. LT collected from each site were homogenized and supernatant obtained used for biochemical analysis. Comparable (p > 0.05) concentrations of total protein, malondialdehyde, reduced glutathione and activities of superoxide dismutase were recorded for LT from all sites. DNA fragmentation was significantly higher in LT from sites (A & B) as compared with those from site C. Activities of catalase decreased in earthworm from sites A to C while nitric oxide levels was higher (p <0.05) in LT from site A compared to those from sites B and C. Earthworm had higher glutathione peroxidase (p < 0.05) activities from site C as compared to A and B. Biotransformation enzyme, glutathione s- transferase activity, was higher (p < 0.05) in LT from site A and B when compared with that of site C. Acetylcholinesterase was also significantly (p < 0.05) inhibited in LT from sites (A & B) compared to earthworms harvested from site C. From the results, it is inferred that sites A and B are more polluted than site C and changes in the biochemical markers suggests genotoxic, oxidative, nitrosative and neurotoxic stress in LT. These biomarkers could be employed to evaluate chemical pollution occurring in the environment. Keywords: Lumbricus terrestris, DNA fragmentation, Kolo Creek, Crude oil, Biochemical markers