Oxidative Stress and Antioxidant Parameters in Earthworm (<i>Esiena fetida andrei</i>); a Probable index of Environmental Pollution Status

Abstract

Oxidative stress and antioxidant responses in earthworms were investigated for use as an index for environmental pollution. The study was done in  three test locations (Refinery road, Okere market and PTI roundabout) in Warri an industrial city in Nigeria and Abraka a less industrial city as  control. Levels of five stress and antioxidant parameters; lipid peroxidation (LPO), aldehyde oxidase (AO), superoxide dismutase (SOD) catalase (CAT) and ascorbic acid (Vit. C.) were used. There was observed significant (p<0.05) rise in LPO (5.83±0.456, 5.83±0.456, 4.04±0.58, 4.25±0.475, 2.09±0.425), oxidative enzyme (AO) levels (0.011±0.00012, 0.008±0.0021, 0.0058±0.0013, 0.0022±0.00009) and increase in activities and levels of the antioxidants (SOD: 24.0±3.80, 12.0±3.80, 16.0±4.62, 5.6±2.8; CAT: 0.98±0.013, 1.08±0.061, 0.95±0.018, 0.93±0.0125 and Vit. C: 0.175±0.0172, 0.118±0.0148, 0.109±0.014, 0.072±0.004) respectively in all study locations in Warri compared to Abraka. These changes were significantly higher in refinery road compared to other locations (Okere market and PTI) in Warri. There were also significant (p<0.05) negative relationship between LPO and SOD activities (r=-0.677), AO and CAT(r=-0.718) as well as AO and SOD(r=0.661) activities respectively only in the refinery road area while no significant change (p>0.05) were reported in other locations. The combined data showed significant negative relationship (p<0.01) between LPO and AO(r=-0.719) and a significant positive relationship (p<0.01) between LPO and (SOD r=0.710, Vit C r=.884). It further showed significant (p<0.01) negative relationship between AO and CAT (r=-0.486), SOD and Vit C (r=-.648), and significant (p<0.01) positive relationship between Vitamin C and (SOD r=-0.865, CAT r=0.785). It was concluded that rise in levels of the studied antioxidants and LPO in earthworms found in Warri compared to Abraka may have occurred in response to industrial pollution, thus may be used for environmental monitoring.

Keywords: Environment, Pollution, Oxidative Stress, Antioxidants and Earthworm