OBJECTIVETo determine the relative molecular mass of marine collagen peptides (MCPs) and investigate the effects of MCPs on serum lipids, anti-oxidative enzymes and malondialdehyde (MDA) in hyperlipidemic rats.

METHODSSephadex G-25, high performance liquid chromatography (HPLC) and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) methods were used to determine the relative molecular mass of MCPs. Then 50 healthy male SD rats were divided into 5 groups, which were normal control (NC) group, hyperlipidemic model control (HC) group and 1.0, 3.0, 9.0 g/kgbw MCPs groups, MCPs were orally administered by gavage to rats in MCPs group for 45 consecutive days (2 ml/100 kgbw per day), and the control rats were given vehicle only, all animals (except NC rats) were fed with a high fat diet composed of 79% basic diet, 10% lard, 10% yolk powder and 1% cholesterol. The levels of serum lipids, the content of MDA and activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured.

RESULTSThe levels of serum total cholesterol (TC) in 1.0, 3.0, 9.0 g/kgbw MCPs groups were 1.89 +/- 0.29, 2.07 +/- 0.39 and 1.99 +/- 0.29 mmol/L respectively, each of which was significantly lower than that in HC group (3.37 +/- 0.24 mmol/L); low-density lipoprotein cholesterol (LDL-C) levels in 1.0, 3.0, 9.0 g/kgbw MCPs groups were 0.83 +/- 0.16, 1.01 +/- 0.35 and 0.91 +/- 0.26 mmol/L respectively, each of which was significantly lower than that in HC group(2.20 +/- 0.34 mmol/L); triglyceride (TG) levels in 3.0 and 9.0 g/kgbw MCPs groups (0.90 +/- 0.15 and 0.86 +/- 0.12 mmol/L) were reduced significantly compared with that in HC group (1.18 +/- 0.18 mmol/L); MDA level in 9.0 g/kgbw MCPs group was 7.1 +/- 4.1 nmol/ml, which was significantly lower than that in HC group ( 15.9 +/- 9.9 nmol/ml); and atherogenic index (AI) in hyperlipidemic rats fed with 1.0, 3.0, 9.0 g/kgbw MCPs were 1.14 +/- 0.22, 1.16 +/- 0.27 and 0.99 +/- 0.31 respectively, each of which was significantly lower than that in HC group (2.27 +/- 0.55). The activities of SOD in 1.0, 3.0, 9.0 g/kgbw MCPs groups (218.6 +/- 33.2, 242.7 +/- 21.4 and 242.1 +/- 44.8 U/ml) were obviously increased compared with that in HC group (119.7 +/- 47.8 U/ml), and anti-atherogenic index (AAI) were also increased significantly (0.47 +/- 0.04, 0.47 +/- 0.06, 0.51 +/- 0.09 vs 0.31 +/- 0.05).

CONCLUSIONMCPs should have antioxidative and lipid-lowering effects, and might play a preventive role in hyperlipidemia and atherogenesis.