The effect of niclosamide on some biological and physiological aspects of Galleria mellonella L. (Lepidoptera: Pyralidae)

The salisilanilides (e.g. niclosamide) function by inhibiting mitocondrial oxidativephosphorylation in parasitic tapeworms and thus they are used as an antiparasitic drug inmedicine and veterinary. While the potent antihelmintic activity of niclosamide has been wellcharacterised in mammals, this study investigated the in vivo insecticide effect of niclosamideusing larvae of the insect Galleria mellonella. Niclosamide was successful in decreasing thesurvival of 7th instar larvae, pupal and adult stages while only the highest concentration ofthis antihelmintic antibiotic (1.0 %) significantly prolonged developmental time to adultstage. Females also increased their fecundity when reared with 0.1 % of niclosamide. On theother hand, we could not obtain any egg in (1.0 %) concentration. An increase in the maleadult longevity was obtained when reared with the highest concentrations of niclosamide.Niclosamid rearing resulted in an decrease in hatchability of eggs. Niclosamide at 0.1 % ofconcentration increased MDA content (4-fold), GST activity (2-fold). Relative to control(133.24 ± 23.6 nmol/mg protein), niclosamide at tested concentrations significantly increasedvABSTRACT (continued)pea content at least 5-fold (70l.24- 808.02 nmol/mg protein). This work indicates that G.mellonella larvae may be used as a good model to ascertain importance of clincally importantantihelmintic drug active ingredients in chemical management of pest insects. The results ofthis work also indicate the negative effects of niclosamide on insect biology is due to its prooxidantproperties and also to the ability of niclosamide in crippling the insect's antioxidandefence response.Key Words: Galleria mellonella, niclosamide, survivorship, malondialdehyde, proteincarbonyl, Glutathione S-transferase, nutritionScience Code: 40l.02.0l