Toxic effects of sub-chronic exposure of male albino rats to emamectin benzoate and possible ameliorative role of Foeniculum vulgare essential oil

• Exposure to emamectin benzoate (EB) induced hematological alterations in male rats.
• EB suppressed humoral immunity of IgG and IgM and increased liver enzymes in exposed rats.
• Tumor necrosis factor-α significantly increased in serum rats due to EB treatment.
• EB induced oxidative stress and decreased antioxidant enzyme of SOD in the treated rats.
• Fennel essential oil, Foeniculum vulgare, improved the previous EB adverse effects in male rats.

Emamectin benzoate (EB) is an avermectin insecticide used extensively in pest control on vegetable and field crops. Few studies have been done for evaluating adverse effects of EB. In the current study, we evaluated the toxic effects of EB on male rats and the possible ameliorative role of fennel essential oil (FEO). Thirty two male rats were randomly divided into 4 equal groups. All groups were treated orally with distilled water (control group), 0.5 ml FEO kg−1 BW (FEO group), 2.5 mg EB kg−1 BW (EB group), and 0.5 ml FEO kg−1 BW + 2.5 mg EB kg−1 BW (FEO + EB group) for 28 days. The obtained results showed that EB treatment resulted in a significant decrease in body weight, body weight gain, RBC count, Hb concentration, % PCV, MCV and MCHC. Moreover, EB significantly decreased total leukocyte, lymphocyte, monocyte and platelet count but significantly increased granulocyte count. EB markedly decreased total protein, albumin, globulin, IgG and IgM concentrations with a significant increase in TNF-α secretion. EB had a negative impact on the liver as it significantly increased ALT, ALP, and MDA, while decreasing SOD activity. Regarding to the histopathological examination, EB treatment induced coagulative necrosis and blood vessels congestion of the liver in treated rats. Furthermore, it resulted in depletion and necrosis of the white pulp of the spleen in treated rats. The co-administration of FEO with EB, however, improved the majority of parameters studied, suggesting that FEO is an important substance in decreasing toxic effects of EB.