Date Published: May 2, 2018
Author(s): Yang Ruan, Hong Li, Lianmei Pu, Tao Shen, Zening Jin.
To investigate the function of Tremella fuciformis polysaccharides (TFPS) in LPS-induced inflammation and oxidative stress of macrophages.
RAW264.7 cells were pretreated with TFPS and then stimulated with 0.1 μg/ml LPS. NFκB, Akt, p38MAPK, MCP-1, and SOD-1 were analyzed by Western blotting. Cell viability was measured using MTT assays. Reactive oxygen species (ROS) production, real-time PCR, ELISA, and immunofluorescence staining were performed on RAW264.7 cells that were treated with LPS and/or TFPS to investigate the anti-inflammatory effect of TFPS.
LPS induced inflammation and ROS production and promoted the secretion of cytokines such as TNF-α and IL-6. LPS also enhanced the nuclear translocation of NFκB, which promoted inflammation by oxidative stress. However, pretreatment with TFPS profoundly inhibited the activation of Akt, p38MAPK, and NFκB and attenuated the expression of MCP-1 in macrophages. Meanwhile, TFPS also decreased cytokine and ROS levels and attenuated cell inflammation after treatment with LPS. Moreover, miR-155, one of the key small RNAs which regulate NFκB and inflammation in macrophages, was significantly downregulated.
TFPS inhibits LPS-induced oxidative stress and inflammation by inhibiting miR-155 expression and NFκB activation in macrophages, which suggests that TFPS may be a potential reagent for inhibiting the development of inflammation.
Antioxidants in food and herbs may prevent free radical-induced cell damage and inflammatory reactions. Many natural plants and fungi contain antioxidant compounds, such as phenolic compounds, which can be used as antioxidants to alleviate the damage caused by free radicals and inflammation . Polyphenols are important natural compounds that can be found in many vegetables, fruits, red wines, and cereals. Epidemiological studies have also revealed a negative correlation between the risk of clinical chronic diseases and the consumption of a polyphenol-rich diet .
In summary, we have demonstrated that TFPS exhibits antioxidative stress and anti-inflammatory properties in LPS-treated macrophages by inhibiting the miR-155 and NFκB pathways, suggesting that TFPS may be a potential therapeutic agent for the treatment of inflammation-related diseases.