Toxicological mechanisms of chlorantraniliprole in Procambarus clarkii: Insight into metabolic disturbances, oxidative stress, and apoptosis.

Chlorantraniliprole (CAP), an anthranilic diamide insecticide widely used in rice-based agroecosystems, may enter rice-crayfish culture systems and affect non-target aquatic animals. This study evaluated CAP-induced gill injury in Procambarus clarkii using histopathology, TUNEL staining, biochemical biomarkers, residue analysis, transcriptomics, qRT-PCR, and western blotting. Crayfish were exposed to 0, 15, 30, and 45 μg/L CAP for up to 96 h, and transcriptomic profiling was performed as an exploratory comparison between the control and a CAP-exposed group at 96 h. CAP accumulated in gill tissues and was associated with epithelial damage, increased apoptosis, altered total hemocyte count, and changes in ACP, AKP, MDA, CAT, POD, T-AOC, ALB, and ATPase-related indices. Several oxidative-stress biomarkers showed non-linear or biphasic responses, suggesting adaptive or hormetic responses rather than a simple monotonic toxicity pattern. RNA-seq and validation analyses indicated that CAP exposure was associated with changes in ribosome-, protein export-, protein processing in the endoplasmic reticulum-, amino-acid metabolism-, and lipid metabolism-related pathways. Western blotting supported changes in apoptosis-, inflammation-, autophagy-related, chaperone, and metabolic proteins; however, the current data do not directly demonstrate unfolded protein response activation or autophagic flux. Overall, CAP exposure caused branchial injury and broad stress-associated molecular remodeling in P. clarkii, while the proposed roles of proteostasis-related disturbance and autophagy impairment should be considered hypothesis-generating and require further validation using markers such as GRP78, CHOP, LC3-II/LC3-I, and direct flux assays.