Interplay between diphenyl diselenide and copper: Impact on D. melanogaster survival, behavior, and biochemical...

Copper (Cu²⁺) is a biologically essential element that participates in numerous physiological processes. However, elevated concentrations of copper have been associated with cellular oxidative stress and neurodegenerative diseases. Organo‑selenium compounds such as diphenyl diselenide (DPDS) have in vitro and in vivo antioxidant properties. Hence, we hypothesized that DPDS may modulate the toxicity of Cu²⁺ in Drosophila melanogaster. The acute effects (4 days of exposure) caused by a high concentration of Cu²⁺ (3 mM) were studied using endpoints of toxicity such as survival and behavior in D. melanogaster. The potential protective effect of low concentration of DPDS (20 μM) against Cu²⁺ was also investigated. Adult flies aged 1-5 days post-eclosion (both sexes) were divided into four groups: Control, DPDS (20 μM), CuSO₄ (3 mM), and the combined exposure of DPDS (20 μM) and CuSO₄ (3 mM). Survival, biochemical, and behavioral parameters were determined. Co-exposure of DPDS and CuSO₄ increased acetylcholinesterase (AChE) activity and the generation of reactive oxygen species (ROS as determined by DFCH oxidation). Contrary to our expectation, the co-exposure reduced survival, body weight, locomotion, catalase activity, and cell viability in relation to control group. Taken together, DPDS potentiated the Cu²⁺ toxicity.