Histological Changes in the Cerebellum of Albino Rats after Inhalational Exposure to Pyrethroid Based Mosquito Repellent

ABSTRACT

Background: There has been an ever increasing use of liquid vaporizers as residential insecticides to get rid of the problem of mosquito and as a concern shown towards prevention of  increasing cases of vector borne diseases. Adverse impact of these chemicals are many  including giddiness, nausea, headache, body ache,  lethargy and dizziness but the current research on the safety of these chemical compounds is market driven and proper histological studies that can establish their toxic effects on cerebellar cortex which acts as higher  centre of coordination, balance and learning are  rare. Accordingly the present  study was planned  to look into the claim of safety of these inhalational compounds and to establish  the correlation, if any between pyrethroid based mosquito repellent inhalational use and the histological insult to the  cerebellum of  Albino rats. Methods: Total of twenty albino rats were marked  into groups marked as control and experimental. The exposure of experimental group was carried out  to 3.2% w/v prallethrin vapours for total of 12 hours in a day and continued for 180 days. The Albino rats in control group were put in similar surroundings but without exposure to any mosquito repellent. The albino rats  were killed after completing exposure of 180 days. The rats brain was dissected and  Cerebellum was taken out. Tissue processing and sectioning done and finally  stained wusing  haematoxylin, eosin and thionin stains. Results: Outer molecular and inner granular layer of cerebellum showed areas of degeneration with disruption and decreased density of cells in Purkinje cell layer. Conclusions: The findings of the  study do confirms that mosquito repellents  given  by inhalational route leads to toxic insult  as evident in this study on Albino rats  on long term  exposure of 180 days as shown by histological alterations  in the sections of cerebellar cortex of rat CNS.