Study On Antioxidant And Protective Effect Of Pearl Oyster(Pinctada Martensii) Mantle Collagen Peptide In Osteoblastic MC3T3-E1Cells

Collagen is an important structural protein, and its hydrolysate exhibits a serious of properties, such as antioxidant activity, antimicrobial activity and osteoporosis inhibitory activity. Fish scales, fish skins and pig skins are usually used as the source of preparing collagens, which are mainly type I collagen. Pearl oyster mantle are rich in type V like collagen, which is different from type I collagen in the composition and sequence of acid amino. In this study, collagen peptides were prepared from pearl oyster mantle collagens using various proteinases. In order to obtain collagen peptides with the highest antioxidant activities, antioxidant capacities of them were evaluated and Sephadex G-25chromatography was used to isolate the antioxidant peptides. Meanwhile, MC3T3-E1cellular model system in vitro was used to investigate the protective effects of collagen peptides against antimycin A (AMA)-induced cell damage. The main research contents were as follows:1Study on the preparation and properties of pearl oyster mantle collagenThe amount of protein in pearl oyster mantle was about9.80g/100g (wet basis), and collagen in pearl oyster mantle was5.6%(wet basis), which account for57.14%of protein. The extraction ratio of mantle collagen through hot water was5.60(dry basis). The analysis of acid amino composition suggested that pearl oyster mantle was rich in acidic amino acids. The collagen had a maximum absorption at202nm, and none at280nm,275nm and257nm.2The preparation and antioxidant activities of pearl oyster mantle collagen peptidesPearl oyster mantle collagen peptides were obtained using alkaline protease, alkaline protease+neutral protease, and alkaline protease+neutral protease+acidic protease, and they were separately named as POMCP1, POMCP2and POMCP3. POMCP2showed the highest antioxidant activity after the determination of antioxidant activities. The radical scavenging activities for DPPH and hydroxyl and reducing power were65.09%,41.36%and0.058, respectively.3The isolation of antioxidant peptide via Sephadex G-25chromatographyPOMCP2was isolated using Sephadex G-25according to the molecular weight and it was fractionated into three portions which were labeled as P1, P2and P3. The molecular weight of PI was about66430Da, while P2and P3were about300-600Da. The radical scavenging activities for DPPH and hydroxyl and reducing power of P2were higher than Pland P3.4Protective effects of mantle collagen peptide on AMA-induced cell damage MC3T3-E1cell line was used to investigate the protective effect of pearl oyster mantle collagen peptide on osteoblastic cell. The results indicated that when the concentration of AMA was80?mol/L and the treating time was48h, a significant growth inhibition was occurred in MC3T3-E1cells. In the absence of AMA, pearl oyster mantle collagen peptide had a non-cytotoxic effect on cell viability of MC3T3-E1cells. Collagen peptide pretreatments increased cell viability compared to the AMA alone group. POMCP2exerted a better protective effect against AMA-mediated oxidative damage than POMCP1and POMCP3. After isolation of POMCP2with Sephadex G-25chromatography, P2preatreatment showed higher cell viability than P1and P3in a concentration dependent manner (0.10-0.80mg/mL). However, the cell viability was decreased at the concentration of1.60mg/mL. Moreover, alkaline phosphatase activity and mineralization ability of MC3T3-E1cells were increased significantly (p<0.05) at concentration dependent manner when pretreated with P2.