Lycium barbarum polysaccharides exert an antioxidative effect on rat chondrocytes by activating the nuclear factor (erythroid-derived 2)-like 2 signaling pathway

Abstract

Introduction: Oxidative stress is the main cause of osteoarthritis (OA). Lycium barbarum polysaccharides (LBP) have antioxidant properties. Thus, the potential effect of LBP on H 2 O 2-stimulated chondrocytes was examined. Material and methods: The cell viability was detected by CCK-8. The reactive oxygen species (ROS) production and apoptosis rates were determined by flow cytometric analysis. The DNA damage was detected by comet assay. Real-time polymerase chain reaction (qPCR) and Western blot assays were performed to examine the expression of histone 2A family member X (γH2AX), checkpoint kinase 1 (Chk1), poly ADP-ribose polymerase (PARP), cysteinyl aspartate specific proteinase (caspase)-3/8/9, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and its antioxidant-response element (ARE) dependent factors including heme oxygenase-1 (HO-1) and quinine oxidoreductase-1 (NQO-1). Results: Compared to the H 2 O 2 group, LBP inhibited the ROS production and DNA damage caused by H 2 O 2 (p < 0.05), respectively. LBP inhibited the mRNA and protein expressions of γH2AX and Chk1 (p < 0.05). Meanwhile, LBP significantly decreased apoptosis (p < 0.05). And LBP inhibited the expression levels of PARP and Caspase-3/8/9 (p < 0.05). Moreover, LBP increased the expression of Nrf2, HO-1and NQO-1 (p < 0.05). Furthermore, the depletion of Nrf2 that mediated by RNA interference reversed the apoptosis and DNA damage inhibition effect of LBP (p < 0.05). Conclusions: LBP protected chondrocytes through inhibiting DNA damage and apoptosis caused by H 2 O 2 , in which the Nrf2/ARE signaling pathway played a positive role. It provided an inspiration for clinical applicationdeveloping LBP as a therapeutic agent and Nrf2 as a promising candidate.

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.…”

G-protein subunit α-14 is dysregulated in human placentas from systemic lupus erythematosus pregnancies

“…Western blotting was performed as described [16,17]. Placental tissues were homogenized on ice and lysed in lysis buffer (Cell Signaling, cat#: 9803) by sonication.…”