Resveratrol Mitigates Imidacloprid-Induced Neurotoxicity, Intestinal Dysfunction and Other Stresses in Newly Emerged Bees (Apis mellifera)

Abstract

Neonicotinoid imidacloprid is an environmentally contaminant that poses a high toxicity to non-target organisms, honey bees (Apis mellifera). Newly emerged bees are critical for colony resilience but vulnerable. This study evaluated the potential of phytochemical resveratrol in mitigating the toxicity induced by imidacloprid in newly emerged bees. To simulate a combined-stress scenario, bees were exposed to imidacloprid at a concentration (0.25 mg/L) that represents elevated field residues. Newly emerged bees were administered a diet supplemented with resveratrol. A series of assays were conducted to evaluate survival rate, physiological indices, histomorphological alterations, enzyme activities, and transcriptomic profiles. The results demonstrated that dietary supplementation with resveratrol (0.6 mg/L resveratrol and 0.25 mg/L imidacloprid) exhibited significantly higher survival rates and improved food utilization efficiency compared to bees exposed to imidacloprid alone. Resveratrol mitigated imidacloprid-induced midgut injury, aberrant sucrose enzyme activity, and restored homeostasis of genes involved in energy and nutrient metabolism (e.g. ATP synthesis, lipid, carbohydrate, and tyrosine metabolism), which were dysregulated by imidacloprid. Resveratrol alleviated oxidative stress via modulated CAT/GST activity and normalized MDA level, and upregulated genes in phase I and II detoxification pathways (e.g. GST, UGTs, P450). Notably, resveratrol attenuated imidacloprid-induced brain injury and alleviated neurotoxicity by preserving cholinergic integrity and modulating gene expression associated with neural signaling pathway (e.g. AChE activity and the expression of nAChR and GABA receptor genes). The present work suggested the protective effects of resveratrol on the newly emerged bees in agroecosystems contaminated with neonicotinoid and provided a promising practical strategy.