Induction of micronuclei in bone marrow cells and hepatotoxicity of one of the most common over-the-counter pyrethroid insecticide products in Nigeria

Abstract

Increasing environmental pollution in the tropics is creating a breeding ground for mosquitoes, leading to increasingly frequent use of insecticides to combat home infestation of mosquitoes, the vector of malarial parasites. Household members are therefore more prone to aerosol exposure and subsequent health effects. We assessed the hepatotoxic and clastogenic effects in rats exposed to different levels of aerosols of one of the insecticides most commonly in used in Nigeria. There were significant (p < 0.05) increases in mean relative liver weights and liver cell counts per mm² in the groups of rats exposed to the aerosols when compared with the control group. In addition, rats exposed to the insecticide aerosols have elevated activities of serum enzymes: γ-glutamyl transferase, aspartate amino transferase and alanine amino transferase, as well as number of micronuclei scored in the bone marrow, at levels that are significantly (p < 0.05) different from the values observed for control group. These findings suggest that the aerosols induce an increase in the liver weight through cell proliferations and show that the insecticide is hepatotoxic and clastogenic in rats. Health risks may therefore be associated with long-term exposure to the insecticide aerosols in humans.

Keywords:

• pyrethroid insecticides
• hepatotoxicity
• clastogenicity
• micronucleus
• amino transferases

Acknowledgments

The authors wish to thank Dr Kim Reilly who painstakingly read through the manuscript on our behalf.