Impacts of Cetylpyridinium Chloride on the Survival, Development, Behavior, and Oxidative Stress of Early-Life-Stage Zebrafish (Danio rerio)

Cetylpyridinium chloride (CPC) is a widely used surfactant that has been detected in various water ecosystems. However, knowledge on the toxicity of CPC to fish remains scarce. Here, we examined the survival, development, behavior, and oxidative stress in the early life stages of zebrafish exposed to CPC (0, 4, 40, 400, and 1200 mu g/L) until 120 h post-fertilization (hpf). Results showed that CPC induced significant mortality at 400 and 1200 mu g/L, with a 120 h-EC50 value of 175.9 mu g/L. CPC significantly decreased the heart rate of embryos (48 hpf; 4-400 mu g/L) and larvae (72 hpf; 40 and 400 mu g/L). At 120 hpf, CPC exhibited a dual effect on the locomotion activity (decreased at 400 mu g/L and increased at 4 and 40 mu g/L) and elevated the reactive oxygen species, superoxide dismutase, and glutathione levels in zebrafish larvae at 400 mu g/L. In addition, a correlation analysis revealed that CPC-induced oxidative stress might play a critical role in mediating the cardiac and behavioral toxicity of CPC to zebrafish larvae. Our findings suggest that CPC may disturb the fish's development, behavior, and oxidative status at environmentally relevant concentrations, which should not be ignored when assessing its potential risks to aquatic ecosystems.