Wood creosote pretreatment of anisakid larvae attenuates extract-induced epithelial dysfunction in vitro

Anisakiasis and parasite-associated hypersensitivity remain important food-safety concerns where raw marine fish is consumed. Although wood creosote (WC) has been studied mainly for effects on anisakid larval motility, its influence on host-relevant epithelial responses to larva-derived products is unknown. We examined whether WC pretreatment of thawed anisakid third-stage larvae alters the biological activity of crude larval extracts in Caco-2 cells. Crude extract from WC-pretreated larvae (CEWC) was compared with paired control extract (CE). CE and CEWC had similar protein concentrations and were not cytotoxic at 0.2-2.0 mg/mL. At 1.0 mg/mL, CE increased Lucifer Yellow flux, whereas CEWC produced a lower increase. Two independently performed cell-stimulation experiments using LPS or IL-1β as positive controls showed concordant reductions in IL-6 and IL-8 secretion and mRNA expression with CEWC compared with CE. At non-cytotoxic concentrations, WC alone caused only small changes from the control and produced cytokine levels clearly below those induced by IL-1β. High-performance liquid chromatography (HPLC) spike-comparison analysis detected WC-associated peaks in CEWC spiked with 1 μg/mL WC but not in unspiked CEWC filtrate under the tested conditions. These findings support an upstream effect of WC pretreatment on epithelial responses to larval material. The concordant protein and transcript results across the two independent experiments support reproducibility of the cytokine findings, although reduced clinical allergenicity was not assessed.