Ternary lithium-ion battery cathode material NCM523 impairs planarian locomotor activity, growth and regeneration

The expanding use of ternary lithium-ion batteries has raised growing concerns about their potential ecological and health risks in recent years. This study aimed to investigate the effects and underlying mechanisms of the ternary lithium-ion battery cathode material lithium nickel-cobalt-manganese oxide (NCM523) on planarian locomotor activity, growth, and regeneration, providing insight into the environmental and ecological hazards. Freshwater planarians (Dugesia japonica) were exposed to NCM523-shrimp paste mixtures via feeding. The median lethal concentration (LC₅₀), locomotor activity, growth, regeneration capacity, oxidative stress markers, and expression levels of related genes were evaluated. Exposure to NCM523 induced significant toxicity in planarians, with a 72-h LC₅₀ of 401.5 μg mg⁻¹ (95% CI: 387.7 to 418.1). Elevated malondialdehyde (MDA) levels and increased superoxide dismutase (SOD) activity, together with reduced glutathione peroxidase (GPx) and catalase (CAT) activities, indicated that NCM523 exposure triggered oxidative stress in a concentration-dependent manner. Concurrently, planarians exhibited reduced locomotor activity and marked delays in both growth and regeneration as NCM523 concentrations increased. These physiological impairments were accompanied by upregulation of regeneration-associated genes, including Dj-GATA4/5/6, Dj-PCNA, and Dj-nlg. In conclusion, these findings demonstrate that NCM523 adversely affects planarian locomotor activity, growth, and regeneration, providing crucial in vivo evidence for assessing the potential ecotoxicological risks of ternary lithium-ion battery cathode materials.