Study On Antioxidation Activity Of Collagen Polypeptides From Sea Cucumber

Sea cucumber has proved as a source of rich nutritional components and biologically active substance. Sea cucumber saponins, triterpene glycosides commonly known as holothurins, have drawn attention because of their wide spectrum of biological effects: antifungal, cytotoxic, hemolytic, cytostatic and immunomodulatory activities. In this study, the bioactive components of Isostichopus badionotus, Isostichopus fuscus and Cucumaria frondosa and their function on immune regulation were determined by chemical analysis and immunological methods. The collagen polypeptides (CP) from several kinds of sea cucumbers body wall were also extracted to investigate and compare the effects of different species of sea cucumbers on the protective effects on vascular endothelial cells and neural cells.The results showed that I. badionotus has the highest content of polysaccharide in the body wall among these three kinds of sea cucumbers. The contents of triterpene glycosides, total amino acids, drug-effective amino acids and delicious amino acids are higher in C.frondosa than in the others. In immunodepression mice, they all can antagonize the decline of thymus/body weight induced by hydrocortisone (P<0.05, P<0.01), increase hemolysin content (HC50) (P<0.05, P<0.01), spleen lymphocyte transformation (P<0.05, P<0.01) and the ability of macrophages for carbon particle clearance (P<0.05, P<0.01). C.frondosa has more remarkable effects in HC50 and phagocytic index than the other two (SNK, P<0.05). It is suggested that these three kinds of sea cucumbers all have remarkable function in immune regulation. The significant effect on immune regulation of C.frondosa correlated to its higher contents of triterpene glycoside and active amino acids in all probability.All doses of CP could protect vascular endothellial cells from injury induced by ox-LDL. Cell proliferation activity, NO content and NOS activity were stimulated significantly (P<0.05, P<0.01), the content of MDA was decreased remarkably (P<0.05, P<0.01). Collagen polypeptides from all the three species of sea cucumbers have the protective effects on vascular endothelial cells oxidative damaged by ox-LDL.The neuroprotective effects of CP from the A.japonicus, I.badionotus and C.frondosa on hydrogen peroxide induced apoptosis in PC12 cells were investigated by the aspects of antioxidant, cell proliferation and enzyme activity. The results showed that all these kinds of CP could protect PC12 cells from injury induced by H2O2. Cell proliferation activity, SOD and GSH-PX activity were stimulated significantly (P<0.05, P<0.01), the content of intracellular ROS and LDH release was decreased remarkably (P<0.05, P<0.01). Collagen polypeptides from all the three species of sea cucumbers have the protective effects on neural cells oxidative damaged by H2O2.