Antioxidant potential and protective effect of modified sea cucumber peptides against H2O2-induced oxidative damage in vitro HepG2 cells and in vivo zebrafish model.

In this study, modified sea Cucumber Peptides (SCP) were prepared by reacting with xylooligosaccharide (XOS) and alginate oligosaccharides (AOS) via glycation. Free radical inhibitory and inhibition of oxidative stress of modified SCP was evaluated using human hepatocellular carcinoma (HepG2) cells and zebrafish embryos. LC-MS analysis revealed that SCPs mainly consist of 40 active peptides, with an average molecular weight of 1122.168 Da and an average length of 11 amino acid residues. For amino acid composition, L-Asparagine, L-Methionine, and L-Aspartic Acid were dominant amino acids in SCP. The result showed that the antioxidant ability of SCP against 2,2-Diphenyl-1-picrylhydrazyl (DPPH), superoxide anion radical (O-2), and Hydroxyl Radical (OH) was significantly improved after modification. In HepG2 cells, the modified SCP showed stronger protection than native SCP native against H2O2-induced oxidative stress by enhancing cell viability and reducing radical oxygen species (ROS) generation. The inhibition effect of SCP was increased after modification with XOS and AOS by 13 % and 19 % respectively. Further studies displayed that the activity of antioxidative enzymes, including Superoxide dismutase (SOD), Glutathione Peroxidase (GPx), and catalase (CAT), was remarkably enhanced, whereas malondialdehyde (MDA) level was reduced compared with native SCP and H2O2-treated groups, thus, improving the intracellular antioxidant defenses. The gene expression analysis showed that the mechanism underlying the modified SCP protective effect may be linked with the capability to regulate Nuclear factor-erythroid factor 2-related factor 2 (NRF2) gene expression. The protective effect of modified SCP against H2O2 in vitro was confirmed in vivo by reduced toxicity in zebrafish embryos via improvement of mortality rate, hatching rate, heart beating rate, and deformities of the zebrafish model. However, SCPAOS conjugate displayed greater antioxidant potentials compared to the SCPXOS, the different effects between SCPAOS and SCPXOS could be due to their different antioxidant activity. Thus, modified SCP could be potentially used as a novel nutraceutical in the preparation of anti-aging food and medicine.

Viability and activity of bifidobacteria during refrigerated storage of yoghurt containing Mangifera pajang fibrous polysaccharides.

UNLABELLED: The viability and activity of Bifidobacterium pseudocatenulatum G4, B. longum BB 536 and yoghurt cultures (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) were studied in yoghurt containing 0.75% Mangefira pajang fibrous polysaccharides (MPFP) and inulin. Growth of probiotic organisms, their proteolytic activities, the production of short chain fatty acids (lactic, acetic and propionic) and the pH of the yoghurt samples were determined during refrigerated storage at 4 °C for 28 d. B. pseudocatenulatum G4 and B. longum BB 536 showed better growth and activity in the presence of MPFP and inulin, which significantly increased the production of short chain fatty acids as well as the proteolytic activity of these organisms. PRACTICAL APPLICATION: This is the first study reported on produce synbiotic yoghurt as a functional food for specified health uses contains bifidobacteria and M. pajang fibrous polysaccharides. M. pajang fibrous polysaccharides can be used as a prebiotic particularly in dairy products to increase the viability and activity of bifidobacteria which can be used as probiotic to exert health benefit to the human by yoghurt that is considered common use in society; thus, the benefits of synbiotic yoghurt are readily accessible to the member of society.

Hypocholesterolaemic effect of yoghurt containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536.

The effect of a yoghurt supplement containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 on plasma lipids, lipid peroxidation and the faecal excretion of bile acids was examined in rats fed a cholesterol-enriched diet. After 8 weeks, the rats in the positive control (PC) group who were fed the cholesterol-enriched diet showed significant increases in plasma total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and malondialdehyde (MDA). However, groups fed a cholesterol-enriched diet supplemented with yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 had significantly lower plasma TC, LDL-C, very-low-density lipoprotein (VLDL) cholesterol, and MDA than had the PC group after 8 weeks of treatment. In addition, faecal excretion of bile acids was markedly increased in the rats fed the yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 as compared to the PC and NC groups.