The Oxidative Stress And Neurotoxicity Of 6 Kinds Of BTEX Activities In Respiratory Tree And Intestine Of Sea Cucumber Apostichopus Japonicus

The present study is aimed to evaluate the oxidative stress effects and neurotoxicities of BTEXs on sea cucumber Apostichopus japonicus, which was one of important benthic organisms in the Yellow Sea and Bohai Sea of China. Three different concentrations(1/5, 1/25, 1/125 of 96–LC50) of benzene, toluene, ethyl benzene, o–, m–, p–xylene were selected to treat the healthy A. japonicus individuals using semi-static water experimental method. The activities of catalase(CAT) and acetylcholin esterase(ACh E), detected by using enzyme activities kit, and relative expression levels of cat and glutathione peroxidase(GPx) genes, detected by quantitative real-time PCR, in respiratory tree and intestine of A. japonicas.The results showed that the activities of CAT and expression levels of cat gene in respiratory tree and intestine were remarkably changed in different BTEXs treatment groups, comparesd to the control, and showed dose–effect relationship. The activities of CAT in respiratory tree were induced in benzene, toluene, ethyl benzene and o–xylene treatment groups, and the highest levels(12.0~19.8 fold) were found in ethyl benzene treatment group. The activities of CAT in intestine were inhibited in BTEXs treatment groups, and the activities in descending order were o–xylene, ethyl benzene, p–xylene, toluene, m–xylene and benzene treatment groups. The expression levels of GPx gene in respiratory tree and intestine were remarkably changed in different BTEXs treatment groups, and showed dose–effect relationship. The expression levels of GPx gene in respiratory tree were down-regulated in benzene, o–xylene and p–xylene treatment group, and the highest levels(2.6~41.7 fold). The expression levels of GPx gene in respiratory tree were up-regulated in toluene and m–xylene treatment groups, and the highest levels(2.6~86.4 fold). The expression levels of GPx gene in intestine were down-regulated in o–xylene, m–xylene and p–xylene treatment group, and the highest levels(1.2~38.5 fold). The activities of ACh E in respiratory tree and intestine were remarkably changed in different BTEXs treatment groups. The activities of ACh E in respiratory tree and intestine were induced in benzene, toluene and ethyl benzene treatment groups. The activities of ACh E in respiratory tree and intestine were inhibited in o–xylene, m–xylene and p–xylene treatment group.These results suggest that BTEXs have oxidative stress effects on the respiratory tree and intestine of A. japonicus, and might have oxidative damage on the two tissues; and they have neurotoxic effects on the respiratory tree and intestine of A. japonicas. These results will provide the basic data for toxic assessment of BTEXs on the sea cucumber A. japonicus.