Exploring the neurotoxicity and changes in life cycle parameters of Drosophila melanogaster exposed to arecoline

Abstract

Arecoline (an alkaloid) has been reported as a potent cytotoxic as well as genotoxic agent but its neurotoxic effects are limited. In the present study, we evaluated the neurotoxic effects and changes in life cycle parameters of Drosophila melanogaster on exposing the flies to 5, 10, 20, 40 and 80 μM of arecoline for 5 days. After the exposure, the flies were assayed for climbing ability, activity pattern, oxidative stress markers, acetylcholinesterase (AChE), monoamine oxidase activity (MAO), caspase-3 and caspase-9 activities and apoptosis in the neuronal cells. For studying the effects on life cycle parameters, duration of pupation, emergence and life span were also studied. The exposure of flies to 5 and 10 μM of arecoline did not show toxic effects, but the flies exposed to 20, 40 and 80 μM showed a significant dose-dependent loss of climbing ability, activity pattern, MAO, glutathione (GSH) content and acetylcholinesterase activity and increase in the glutathione-S-transferase (GST), MAO activity, lipid peroxidation assay (LPO), protein carbonyl content (PCC), caspase-3 and caspase-9 activities and apoptosis in the neuronal cells. The exposure of flies to arecoline not only results in the delay of pupation but also delayed the emergence of flies. A significant reduction was also observed in the life span of flies exposed to 20, 40 and 80 μM of arecoline. The eyes of flies emerged from the larvae exposed to various doses of arecoline were also analysed for the phenotypic abnormality. Clear dose-dependent deformities were observed in the eyes of the flies emerged from the exposure of larvae exposed to 20, 40 and 80 μM of arecoline. Arecoline not only is a neurotoxic agent but also affects the life cycle parameters of the fly.