The Effect Of Dendrobium Nobile Lindl. Polysaccharides On Oxidative Stress And Expression Of Nrf2in Rat Glomerular Mesangial Cell Cultured In High Glucose

Objective:To explore the effect of Dendrobium nobile Lindl. polysaccharides in oxidative stress and Nrf2protein expression on rat mesangial cells induced by high glucose and to investigate the possible mechanism of polysaccharides involved in.Methods:1. Water extraction and alcohol precipitation was used to extract polysaccharide and DEAE sepharose fast flow was used to further separation and purification crude polysaccharides. Identification methods include:the polysaccharide characteristic absorption peak was identified by infrared spectrum; polysaccharide purity was determined by ultraviolet spectrophotometry; the polysaccharide content was measured by phenol-sulfuric acid method.2. the HBZY-1cells were divided into normal control group (NC), high glucose group (HG), the NAC treated group (NA), the Dendrobium nobile Lindl. polysaccharides low (LD), medium (MD), high (HD) dose group,after24h of drug action, total antioxidant capacity of cells in each group were detected by ABTS method; reactive oxygen species by flow cytometry; cell proliferation in each group was examined by WST-1assay.3. Nrf2, NQO1mRNA expression level were detected by real-time fluorescence quantitative PCR and nuclear translocation of immunofluorescent cells was observed. Intracellular Nrf2protein expression was detected by immunodetection.Results:1. FDP1, the components of Dendrobium nobile Lindl. polysaccharide, was purified by Water mention and alcohol precipitation and anion exchange column, showing the polysaccharide relative content was98.1%by phenol-sulfuric acid method.2. Compared with normal control group, the total antioxidant capacity of cells in high glucose group was decreased, while the ROS was significantly increased (P<0.05). Compared with high glucose group, the attenuation of antioxidant capacity and increase of ROS were significantly inhibited by FDP1treated groups (P<0.05). In addition, cell proliferation of high glucose group was faster than normal control group (P<0.05), however, cell proliferation induced by high glucose was not inhibited by FDP1treated groups.3. Nrf2mRNA and Nrf2protein expression levels were significantly increased in FDP1treated groups (P<0.05), and the Nrf2protein nuclear translocation was promote. Meanwhile, NQO1mRNA expression levels were also increased (P<0.05).Conclusions:Dendrobium nobile Lindl. Polysaccharides inhibit both the decreased total antioxi dative capacity and the increased ROS production of HBZY-1s induced by high glucose, and enhance NQO1mRNA expression via promoting Nrf2expression and Nrf2protein nuclear translocation, in order to resist the insult of high glucose-induced oxidative stress, which protect intracellular redox homeostasis.