Toxicological Examinations Following Oral Administration of Bacillus thuringiensis var kurstaki Biological Insecticide in Wistar Rats

Bacillus thuringiensis var kurstaki is one of the best known biological insecticide which is used extensively in the world. This biopesticide has been broadly used against important insect pests and vectors of animals and humans. However, the controversial data was published to date considering toxicological studies on non-target species are urgent to determine probable adverse effects and risk assessment of this biopesticide. In this research, histopathological changes, hematological and some biochemical factors were evaluated following the single dose oral administration of B. thuringiensis in rats. Twelve Wistar rats were randomly divided into 2 groups including experimental and control groups. Animals were treated orally by gavage to single dose of sub-lethal dose (5000 mg/kg) of B. thuringiensis suspension. Finally, hematological factors (WBC, RBC, Hb, HCT, MCV, MCH, MCHC and PLT), some biochemical parameters (ALT, AST, ALP, BUN and Cr) and histopathological observations were evaluated. The results demonstrated that oral administration of high dose of B. thuringiensis biopesticide induced some pathological complications including congestion and inflammation in vital organs of rats such as liver, heart, lung and kidney. It also caused hematological abnormalities and biochemical alterations in the experimental animals group. According to the findings, it can be concluded that high dose of B. thuringiensis biopesticide can induce toxicity in rats. Therefore, further investigations including subacute and chronic are recommended.