Dose-dependent metabolic and oviposition effects of lithium cobalt oxide in Drosophila

Lithium cobalt oxide (LiCoO2 or LCO) is a widely employed cathode material in rechargeable lithium-ion batteries and has garnered attention due to its potential environmental impact. In our study,adult Drosophila melanogaster was exposed to varying concentrations of lithium cobalt oxide (0, 1 mg/L, 10 mg/L, and 100 mg/L) for 20 days. We measured several parameters, including energy metabolism, food intake, oviposition, spontaneous activity, and tube-level group inactivity. Female fruit flies exhibited increased lipid and glucose levels after exposure to LCO, while males showed a decrease in both. Changes in food intake and protein levels were observed but did not reach statistical significance. Significant decreases in egg laying were evident at the highest concentration. Moreover, locomotor activity and tube-level group inactivity exhibited dose-dependent variations, with flies experiencing decreased activity and increased tube-level group inactivity. Our findings demonstrate that long-term exposure to LCO can induce alterations in energy metabolism, egg laying, locomotor activity, and tube-level group inactivity in adult Drosophila melanogaster. These effects were observed in a dose-dependent way. This study contributes to understanding the potential ecological consequences and impacts on insects associated with the widespread use of this material.