Alterations in certain oxidative, physiological, neurological, and immune parameters in the skin of cyprinus carpio exposed to triclosan

Abstract

Triclosan is one of the most widely used antibacterial additives in several personal care products (PCPs). Despite significant advances in understanding the effects of triclosan (TCS) on various aquatic organisms over the past two decades, its impact on the integrity of fish barrier function remains unexplored. The present study aims to investigate oxidative, physiological, neurological and immune parameters in the skin of Cyprinus carpio on exposure to three sublethal concentrations (1 µg/L, 10 µg/L, and 100 µg/L) of TCS at 7 day (d), 14 d, 21 d, and 28 d. The findings of the study revealed a significant (p < 0.05) decline in the activity of antioxidant parameters - superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), and reduced glutathione (GSH) content. In contrast, a significant (p < 0.05) increase in the activity of metabolic enzymes - acid phosphatase (ACP), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and oxidative stress parameters - lipid peroxidation (LPO) and nitric oxide (NO) levels was observed till 28 d. TCS significantly (p < 0.05) inhibited acetylcholinesterase (AChE) activity from 7-28 d, resulting in the accumulation of acetylcholine (Ach) content at the end of 28 d. Further, a dose-dependent (p < 0.05) increase in cortisol, glucose, triglyceride, and cholesterol levels was observed at the end of 28 d. Significant (p < 0.05) increase in the percentage of CD8+ T cells in the exposed groups was observed at 28 d. Additionally, significant (p < 0.05) increased levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), along with a decline in interleukin-10 (IL-10), were noted at the end of the exposure period. Alterations in the stress, physiological, and immunological parameters indicate a shift toward inflammation, tissue damage, and increased vulnerability to infections. The results of this study suggest that TCS present in natural aquatic systems may disrupt skin physiology, potentially compromising the overall health of fish. Further, it emphasizes the need to regulate TCS usage in PCPs mitigating potential adverse effects on non-target aquatic organisms. © 2025 Informa UK Limited, trading as Taylor & Francis Group.