Evaluation of antioxidant enzymes performances and DNA damage induced by bisphenol A and diisobutylphthalate in Hyperiodrilus africanus-earthworms

Abstract

Background

Bisphenol A (BPA) and diisobuthylphthalate (DIBP) have found wide applications as plasticizers; however, they are covalently bonded to materials and are subsequently leached into the environment.

Methods

This study evaluated the effects of BPA, DIBP and mixtures of BPA and DIBP on the antioxidant enzymes [superoxide dismutase (SOD), peroxidase (POD)] activities using standard methods and DNA profile of earthworm (Hyperiodrilus africanus) using randomly amplified polymerase chain reaction (RAPD-PCR) method. A total of 2 kg soil samples collected from FADAMA Farm, Federal University of Agriculture, Abeokuta were spiked to obtain 1, 2.5, 5 and 10 ppm of BPA, DIBP and mixtures of BPA and DIBP. Earthworms were exposed to the unpolluted and spiked soil samples and were collected on the 7th and 14th day for SOD, POD and DNA analysis.

Results

SOD activity was more pronounced at 5 and 10 ppm concentrations. POD activity was increased in all concentrations, including the control, meanwhile POD activity induced by BPA and DIBP was significantly higher (p < 0.05) at 10 ppm compared to other concentrations. RAPD-PCR analysis revealed varying DNA fragment lengths due to excessive oxidative stress generated by the treatments, resulting in DNA damage. BPA and DIBP mixtures generated more fragments of DNA on day 14 than other treatments.

Conclusions

This study established that antioxidant activity decreases with exposure time to BPA and DIBP, while DNA damage increases with exposure time.