Pre-treatment with melatonin decreases abamectin induced toxicity in a nocturnal insect Spodoptera litura (Lepidoptera: Noctuidae)

•Oxidative stress is an important component of the mechanism of pesticide toxicity.•To investigate time-dependent melatonin effects against abamectin oxidative stress in S.litura.•ABA group showed significant changes in the ROS and carbonyl content in midgut.•PM showed increase of SOD, GST, CAT, POX, APOX levels in midgut.•Indoleamine can play a vital role curtailing the abamectin toxicity in time dependent.

AimOxidative stress is an important component of the mechanism of pesticide toxicity. The aim of the present study was to investigate the time-dependent melatonin effects against abamectin-induced oxidative stress in a S.litura model. Larvae were divided into 5 different groups; (1) control group,(2) Melatonin group (4.3 × 10−5 M/100 ml diet), (3) Abamectin group 1.5 ml/L, (4) Pre-melatonin treated group (PM) (4.3 × 10−5 M/100 ml diet) before abamectin exposure 1.5 ml/L, (5) Post-melatonin treated group (TM) after abamectin exposure. Melatonin was supplemented via artificial diet in PM and TM animals during 24 h.Main methodsMidgut, fatbody, and hemolymph, were collected for the analysis of oxidative stress markers (Total ROS, GSH, nitrite, TBARS, LPO), antioxidant enzyme levels (SOD, GST, CAT, POX, APOX) in fifth instar larvae. Midgut damage was examined by using morphological analysis.Key findingsOur results observed that ABA group showed significant changes (p < 0.001) in the ROS and carbonyl content in midgut. The increase of antioxidant enzyme levels (SOD, CAT, POX, and APOX) in midgut was led by the continuous free radical scavenger cascade of melatonin. Significant (p < 0.01) increases in CAT and APOX levels were seen in the fatbody of PM and TM treated insects.SignificanceIn conclusion, the results of the study revealed that abamectin toxicity generates oxidative stress in the insect, while pre-melatonin treatment reduces this damage due to its antioxidant properties, especially POX levels in midgut, fatbody, and hemolymph. Therefore, indoleamine can play a vital role curtailing the abamectin toxicity in time dependent manner in S.litura.

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