Mammalian Biosafety of Bacillus thuringiensis subsp. kurstaki -Based Bioinsecticide

Abstract

Bacillus thuringiensis subsp. kurstaki (Btk) is well-known and widely used as a biological insecticide. Registration of biopesticides with the national pesticides broad must be laboratory testing for acute toxicity as short-term and long-term health effects. Acute oral toxicity tests were carried out on rats with -endotoxin and formulation (9.4% WP) of Btk based on the Organization for Economic Co-operation and Development (OECD). The purpose of this study is to assess the biosafety of the bioinsecticide Btk (-endotoxin and 9.4% WP) in adult rats after a single oral dose based on hematotoxicity, hepato-renal toxicity, and the lipid profile. Results illustrate that most haematological parameters increased in treated rats. Compared to the control, liver enzymes (AST, ALT, and ALP) and globulin (Glb) concentration were increased and decreased in male rats subjected to both kinds of Btk. While female rats treated with both Btk products are showing a significant elevation in ALP, total protein (TP), albumin (Alb), and Glb levels versus the levels of ALT and AST. Urea concentrations decreased significantly in all treated rats, but Creatinine levels appeared to remain unchanged. Moreover, there was a decline and elevation in the serum of lipid profiles (T cholesterol and HDL) in treated male rats and female rats, respectively. LDL levels increased in treated male animals, while they decreased in treated females. All treated animals displayed negligible modifications in tissue somatic index, except a slight increase in lung weights when compared to the control. Contradictory, the body weight gain levels were reduced in all treated animals compared to untreated. In addition, there are no mortality or pathogenicity symptoms in all treated animals. These findings suggest that both treatments can induce hepato-renal toxicity and hematotoxicity with side effects on lipid profile aspects. Therefore, additional research, including subacute and chronic studies, is recommended.