Schisandra chinensis polysaccharides exerts anti-oxidative effect in vitro through Keap1-Nrf2-ARE pathway

Abstract Schisandra chinensis polysaccharide (SCP) is extracted from a well-known traditional Chinese medicine Schisandra chinensis (SC). We purified a new compound and would like to analyze the effect of SCP on oxidative stress (OS) in vitro. SCP was identified by high performance liquid chromatography (HPLC) and infrared spectrum (IR). The effect of SCP on cell proliferation, activity of oxidative and anti-oxidative index superoxide dismutase (SOD), catalase (CAT), malonaldehyde (MDA), glutathione (GSH), protein expression of nuclear factor E2-related factor 2 (Nrf2) and its down-stream factors expression, stability of Nrf2, and binding activity of Nrf2 with DNA were tested using different methods in 293T cells. The result showed that SCP enhanced the cell proliferation of 293T cells, the contents of GSH and CAT, and the activity of SOD, while decreased the content of MDA. In addition, SCP promoted the transfer of Nrf2 from cytoplasm to nucleus, the binding activity of Nrf2 with DNA, the stability of Nrf2 protein, and prolonged the half-life of Nrf2. SCP showed a strong anti-oxidative activity and activation of the Nrf2 pathway, indicating that SCP had the potential to be developed into the natural anti-oxidant in the future.