Study On The Protective Effect And Mechanism Of Curcumin On Lung Injury Induced By Outdoor Fine Particulate Matter(PM2.5)

Background:Air pollution has become the number one killer of human beings.According to the world health organization,90 percent of the world’s people breathe polluted air every day,and air pollution causes 7 million deaths a year from cancer,stroke,heart disease,lung disease And other diseases.Epidemiological studies have shown that exposure to particulate matter(PM)induces oxidative stress,leading to a variety of health problems.In particular,fine particles(PM2.5)contain a large number of toxic and harmful substances,which can penetrates into the lungs to induce lung injury.It has been shown that curcumin can reduce oxidative stress and inflammation damage caused by smoking,but it is still rare to find out whether it also has a protective effect on lung damage caused by PM2.5.Objective:To explore the possible mechanism of curcumin’s protective effect on PM2.5-induced oxidative stress and inflammatory damage,and provide a certain experimental basis for the development and application of curcumin in the future.Methods:28 SPF grate male Kunming mice were randomly divided into 4 groups:Control group(CON),Saline group(NS),PM2.5 group(PM2.5)and Curcumin group(CUR).The mice were handled by intratracheal instillation of PM2.5.Spectrophotometric detection of oxidative stress indicators such as MDA,CAT and GSH-PX in lung tissue;The level of IL-6 and TNF-α levels in lung tissue were determined by ELISA;Histopathological examination for assessment of alveolar Epithelial damage;The endogenous CO was also detected by spectrophotometryin lung tissue;The protein expression of HO-1 and P38 MAPK in lung tissue was determined by Western blot and immunohistochemistry.Results:The MDA level of CUR group and PM2.5 group was higher than that of CON group and NS group,with statistical difference(p<0.05);the CAT activity level of CUR group and PM2.5 group was lower than that of CON group and NS group(p<0.05).GSH-PX activity level in CUR group and PM2.5 group was lower than that in CON group and NS group(p<0.05).Compared with CON group and NS group,the expression of HO-1/CO,P3 8 MAPK was significantly increased in CUR group(p<0.05).Compared with CON group and NS group,the expression of HO-1/CO,P38 MAPK in PM2.5 group was significantly increased(p>0.05).MDA,TNF-α and IL-6 levels of oxidation and inflammation indicators in curcumin intervention were lower than those in PM2.5 group,but there was no significant difference(p>0.05);The activities of CAT and GSH-PX in the CUR group were higher than those in the PM2.5 group,and the difference was not statistically significant(p>0.05).Compared with PM2.5 group,the expression of HO-1/CO,P38 MAPK in CUR group was significantly higher than that in PM2.5 group(p<0.05).Conclusion:1.Exposure to PM2.5 can induce lung tissue damage in mice;2.Exposure to PM2.5 increased the expression of HO-1/CO and P38 MAPK in the lung tissue of mice to combat the oxidative stress and inflammatory damage caused by PM2.5;3.Curcumin can further increase the expression of HO-1/CO and P38 MAPK in lung tissue and reduce the oxidative stress and inflammatory damage caused by PM2.5.