Anti-Osteoporotic Effect of Viscozyme-Assisted Polysaccharide Extracts from Portulaca oleracea L. on H2O2-Treated MC3T3-E1 Cells and Zebrafish

Abstract

This study aims to screen and characterize the protective effect of polysaccharides from Portulaca oleracea L. (POP) against H2O2-stimulated osteoblast apoptosis in vivo and in vitro. The enzymes viscozyme, celluclast, α-amylase, and β-glucanase were used to extract POPs. Among all enzyme-assisted POPs, the first participating fraction of viscozyme extract POP (VPOP1) exhibited the highest antioxidant activity. Hoechst 33342 and acridine orange/ethidium bromide staining and flow cytometry of MC3T3 cells revealed that VPOP1 inhibited apoptosis in a dose-dependent manner. Moreover, VPOP1 increased the expression levels of heme oxygenase-1 (HO-1) and NADPH quinine oxidoreductase 1 (NQO1) and decreased the expression levels of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and Kelch-like ECH-associated protein 1 (Keap1) in H2O2-induced cells compared with their controls. The results of an in vivo experiment show that VPOP1 significantly reduced reactive oxygen species generation and lipid peroxidation in zebrafish at 72 h post-fertilization and promoted bone growth at 9 days post-fertilization. Furthermore, VPOP1 was identified via 1-phenyl-3-methyl-5-pyrazolone derivatization as an acidic heteropolysaccharide comprising mannose and possessing a molecular weight of approximately 7.6 kDa. Collectively, VPOP1 was selected as a potential anti-osteoporotic functional food because of its protective activity against H2O2-induced damage in vitro and in vivo.

Advances in health-promoting effects of natural polysaccharides: Regulation on Nrf2 antioxidant pathway

“…Cell experiments have demonstrated that NPs from herbs could regulate Nrf2 antioxidant pathway for liver protection ( 14 , 117 – 120 ), kidney protection ( 59 , 60 ), lung protection ( 20 ), neuroprotection ( 22 , 65 , 121 – 123 ), cardioprotection ( 19 , 124 , 125 ), gastrointestinal protection ( 48 , 55 , 61 , 62 , 66 , 126 – 128 ), anti-oxidation ( 85 , 129 – 134 ), anti-diabetic ( 135 – 137 ), anti-aging ( 138 – 141 ), anti-inflammation ( 67 , 69 ), anti-radiation ( 28 , 142 ), and immunomodulation ( 143 ), as illustrated in Table 1 .…”

“…Those from herbs exhibited anti-diabetic effect on palmitate-induced HepG2 cells ( 135 ), high glucose-induced ARPE-19 cells ( 136 ) or HRECs ( 146 ), and high-glucose- and high-insulin-induced 3T3-L1 adipocytes ( 137 ) by augmenting protein or mRNA expressions of p-Nrf2/Nrf2, Nrf2, HO-1, SOD2, CAT, and nuclear Nrf2 as well as nuclear translocation of p-Nrf2. NPs from herbs showed anti-aging activity against H 2 O 2 -induced chondrocytes ( 138 ), H 2 O 2 -induced ARPE-19 cells ( 139 ), ADM, ODM, ADM + H 2 O 2 , or ODM + H 2 O 2 -induced BMSCs cells ( 140 ), H 2 O 2 -induced MC3T3-E1 cells ( 141 ) through rising mRNA and/or protein expressions of Keap1, Nrf2, HO-1, and NQO1 as well as nuclear Nrf2. Polysaccharides from Dendrobium officinale ( 67 ) and Apios americana ( 69 ) produced anti-inflammation on LPS-induced RAW264.7 cells partly by adding protein and/or mRNA expressions of Keap1, Nrf2, HO-1 and NQO1.…”