Histopathological and Biochemical Effects of Selected Mosquito Chemical Repellents on the Liver of Adult Wistar Rats

Abstract

Background: Repeated outbreak of malaria compelled many into the use of mosquito chemical repellents in Africa most populous nation, Nigeria. Despite successes achieved, human health issues are major concern nowadays regarding the volatile-active agents and by-products of most mosquito chemical repellents. Hence, the need to evaluate histopathological and biochemical effects of commonly used mosquito repellents on the liver as body’s centre for detoxification. Materials and Methods: Forty five Wistar rats were divided into five groups of nine rats kept in plastic cages measuring 53.5 cm x 39.5 cm to inhale vapours of selected brands of mosquito repellents for 5 minutes/day over a period of 21 days. A group of animals without exposure to repellent vapours served as normal control. Three animals from each group were sacrificed at week 1, 2 and 3 respectively. Biochemical and histopathological studies were performed following physical observations of toxicity signs. Results: Exposure of Wistar rats to mosquito repellents for 5minutes/day over a period of 21 days did not cause mortality. Liver enzymes showed significant increase in rats exposed to liquid form of repellents (Rambo and Sharp) (P < 0.05, Bonfeeroni test = 0.04) corroborated by sinusoid dilatations, cytoplasmic vacuolation and on-going apoptotic cells. Coil form of repellents (Wave tide and Baoma) did not show significant change in liver enzymes (P > 0.05) but there was histopathological changes compared to normal liver. Conclusion: Wistar rats exposed to liquid and coil vapours of mosquito repellents for 5minutes/day over a period of 21 days caused liver injury.