The effects of levamisole in Greater Wax Moth larvae hemolymph

Galleria mellonella is a Lepidopteran pest insect infesting the
honeycombs, and the last instar larva of the insect is also a valuable
model organism for evaluating drug efficacy, pathogenicity of infectious
agents, and environmentally sound chemical insecticides. Levamisole is an
anthelmintic drug that is used for the treatment of parasitic infections
in animals. In this study, we investigated the oxidative and genotoxic
effects of dietary levamisole on the hemolymph of the G. mellonella last
instars to evaluate levamisole as an alternative chemical for traditional
insecticides. In this context, first instar larvae were reared up to the
last instars in artificial diets containing levamisole (w/w) and a control
diet without levamisole. Malondialdehyde (MDA), and protein carbonyl (PCO)
contents, and the activity of antioxidant enzymes including superoxide
dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST) and
glutathione peroxidase (GPx) were determined to evaluate oxidative stress
in the hemolymph of G. mellonella last instars. Furthermore, the
comet assay was performed on hemolymph to evaluate DNA damage levels. The
dietary levamisole led to a significant decrease in MDA and PCO contents,
and antioxidant enzyme activities (SOD, CAT, GST and GPx) when compared to
control diet. However, dietary levamisole significantly increased tail
moment, tail %DNA, and tail length, which are strong indicators of DNA
damage. We infer from these that levamisole induced DNA damage and
crippled antioxidant enzymatic defense in correlation with gradually
increasing dietary concentration. The study would also provide valuable
insights into the multifunctional aspects of levamisole, including its use
in pest management.