Combined effects of pentachlorophenol and nano-TiO with different sizes on antioxidant, digestive, and immune responses of the swimming crab Portunus trituberculatus.

Marine nano-titanium dioxide (nano-TiO) and pentachlorophenol (PCP) pollution are escalating concerns in coastal areas. This study investigated the combined effects of continuous exposure to nano-TiO (25 nm, 100 nm) and PCP (0, 1, 10 μg/L) for 28 days on the antioxidant, digestive, and immune abilities of the swimming crab Portunus trituberculatus. Compared with the control group, the interaction between nano-TiO and PCP was significantly higher than exposure to a single stressor, with a pronounced decrease in amylase activity observed due to the reducing nano-TiO particle sizes. Resulting in increased MDA and SOD activity. The expression levels of Toll4, CSP3, and SER genes in crab hemolymph showed perturbations following exposure to nano-TiO and PCP. In summary, according to the results of CAT, GPX, PES and AMS enzyme activities, it was concluded that compared to the larger particle size (100 nm), the single stress of nano-TiO at a smaller particle size (25 nm) and co-stress with PCP have more significant impacts on P. trituberculatus. However, the potential physiological regulation mechanism of the interaction between these pollutants remains elusive and requires further study.