Study On Oxidative Stress Involved In UV-induced Sea Cucumber Stichopus Japonicus Autolysis Starting Relevant Factors

Sea cucumber is the most common marine invertebrates, yield very rich, not only has food and health benefits, but also has a high economic value. However, under the stimulus of external environmental factors, sea cucumbers prone to autolysis, this kind of phenomenon to the sea cucumber brings a lot of inconvenience, such as fresh-keeping, storage, transportation and processing, caused great nutritional and economic losses. To enrich the sea cucumber autolysis theory, solve the problems which are caused in the processing and storage of sea cucumber autolysis, living sea cucumber (Stichopus japonicus) were as the study objects. Under UVC irradiation, live sea cucumber autolysis were induced, several enzyme and factors were detected, such as the acetylcholinesterase (AchE), cathepsin L, Caspase-3, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), acid glutathione (GSH), protein carbonyl and hydrogen peroxide (H2O2) contentthe guts and body wall. Fresh sea cucumber gut were also used as raw materials, several enzyme and factors were detected, such as acetylcholinesterase (AchE), cathepsin L, Caspase-3, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acid glutathione (GSH) content. Finally, sea cucumber gut and body wall extracts were prepared from fresh sea cucumber, the removal ability of DPPH, hydroxyl radical and superoxide anion were analysis using electron spin resonance (ESR) technology.The rusults showed that for the living sea cucumber, after UVC irradiation, in the gut and body wall, AchE enzyme activity decreased 36.16%,55.7%, cathepsin L and caspase-3 activity increased 52.37%,69.27% and 2.8,4.09 times, indicated that UVC induced living sea cucumber to happen autolysis phenomenon. And SOD, CAT, GPx activity decreased 24.7%, 38.79%,36.18%,44.27% and 33.79%,79.54%, as the extension of UVC irradiation time, at the same time, the increase (66.71%,75.31%) of the content of GSH is proved from the side, after the living sea cucumber induced by UVC, the oxidative stress reaction occur in the body. Protein carbonyl and H2O2 content increased with the extension of UVC irradiation time, illustrate that the sea cucumber, after UVC induced the gut and body wall oxidative damage, and is accompanied by peroxide generated; Fresh sea cucumber after UVC irradiation, the AchE enzyme activity decreased 64.04%, cathepsin L and Caspase-3 activity respectively increased by 1.9,2.97 times, SOD, CAT, GPx activity decreased 32.37%,77.29%,35.93%. GSH content increased 65.19% as the extension of UVC irradiation time, these results consistent with the change trend of UVC induced living sea cucumber; fresh sea cucumber gut and body wall extracts has good scavenging effect on the DPPH free radical, hydroxyl radical and superoxide anion. Sea cucumber gut and body wall extracts to IC50 values of DPPH scavenging abilities were 0.91 μg/mL and 1.29 μg/mL; IC50 of hydroxyl radical scavenging abilities were 0.006 ug/mL and 0.52 ug/mL; IC50 of superoxide anion scavenging abilities were 0.89 μg/mL and 0.47μg/mL. Under the condition of the same concentration, the sea cucumber gut extract on DPPH and hydroxyl free clearance is higher than the body wall.Study on the live sea cucumber and fresh sea cucumber gut autolysis related enzymes, antioxidant enzymes, antioxidants and peroxides to enrich sea cucumber autolyzed mechanism, solve the problem of sea cucumber storage process to provide certain theoretical basis. Meanwhile study on the sea cucumber gut and body wall extracts’ antioxidant activity applied to ESR techniques for rapidly detected antioxidant activity of aquatic products provide an efficient, rapid means of detection.