| BackgroundWith the continuous advancement of industrialization and urbanization,air pollution has become a major problem affecting the global respiratory health,and the particulate matter(PM)exposed to the urban air will seriously affect human health.It has been proved that curcumin can reduce lung injury caused by tobacco smoke in many ways,but whether curcumin can also protect pm2.5-induced lung injury,there are few related studies.In this study,we observed the protective effect of curcumin on lung injury in mice exposed to PM2.5 and explored its possible mechanism.Objective:To explore the mechanism of curcumin activating Nrf2/HO-1 signal pathway to improve pm2.5-induced lung injury.It provides some experimental basis for the development and application of curcumin in the future.Method:Twenty eight SPF male Kunming mice were randomly divided into four groups:blank control group,normal saline control group,PM2.5 treatment group and curcumin intervention group.The lung injury model of mice was established by intratracheal instillation of PM2.5.Curcumin(100mg/kg)was intraperitoneally injected one week before the induction of PM2.5.The mice were killed 72 hours after PM2.5 exposure,and the lung tissue and bronchoalveolar lavage fluid(BALF)were collected for analysis.Results:1.Pathological changes of lung tissue:under the light microscope,he staining of the lung tissue of mice in the normal saline group showed that the bronchi,alveoli and alveolar septum were clear,the structure was relatively complete,no obvious inflammatory cells,no interstitial edema,hyperemia and exudation,no obvious expansion and hyperemia of the capillary between the alveoli;PM2.5 particles accumulation and interstitial edema were found in the lung tissue of mice in the PM2.5 group,There were obvious thickening,fusion and fracture of alveolar septum,destruction of alveolar structure,thinning of alveolar wall,necrosis and abscission of epithelial cells,dilation of capillary tube wall,infiltration and secretion of inflammatory cells in lumen and airway;pathological manifestations such as thinning of alveolar wall and infiltration of interstitial inflammatory cells were found in curcumin group,but its inflammatory state was better than PM2 5 groups were relieved.2.Comparison of related detection indexes in BALF:compared with the control group and saline group,the levels of LDH,ALP and ALB in BALF in PM2.5 group were significantly higher(P<0.05);compared with PM2.5 group,the contents of LDH,ALP and ALB in BALF in curcumin group were lower,but no statistical significance(P>0.05).3.Comparison of inflammatory indexes in lung tissue:compared with the control group and normal saline group,the levels of TNF-α and IL-6 in lung tissue of PM2.5 group were higher,the difference was statistically significant(P<0.05)Compared with PM2.5 group,the content of the above inflammatory indexes in curcumin group decreased,but there was no significant difference(P>0.05).4.Comparison of antioxidant indexes in lung tissue:compared with the control group and the normal saline group,the MDA level,Nrf2 and HO-1 expression in lung tissue of PM2.5 group were significantly higher,and the levels of antioxidant enzymes such as tao-c,GSH-Px and cat were significantly lower(P<0.05);compared with PM2.5 group,the MDA level in lung tissue of curcumin group was lower,The levels of antioxidant enzymes such as tao-c,GSH-Px and cat increased(P>0.05);the levels of Nrf2 and HO-1 in the lung tissue of curcumin group were significantly higher than those of PM2.5 group(P<0.05).Conclusion:1.PM2.5 can induce oxidative stress and inflammation,and lead to lung injury;2.Curcumin can activate the expression of Nrf2 and its downstream product HO-1,and prevent pm2.5-induced injury. |
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