Effect of curcumin on nano-silicon dioxide induced oxidative damage in A549 cells / 中国职业医学

ABSTRACT

OBJECTIVE: To study the effect of curcumin on the oxidative stress induced by nano-silicon dioxide( SiO_2) in A549 cells and to explore its potential mechanism. METHODS: A549 cells were randomly divided into 6 groups. Nano-SiO_2 group cells were stimulated with nano-SiO_2 solution with a final concentration of 20 mg/L; curcumin low-,medium-,and high-dose group cells were treated with curcumin at final concentrations of 5,10,and 20 μmol/L respectively and 20 mg/L nano-SiO_2 solution; the solvent control group was treated with dimethyl sulfoxide with a volume fraction of 0. 10%. The cells in the blank control group were not given any treatment. The cells in these 6 groups were incubated for 12 hours,and the level of malondialdehyde( MDA) and the activity of total superoxide dismutase( T-SOD) in the cells were measured by spectrophotometer. The relative expression of mRNA and protein of nuclear factor E2-associated factor 2( NRF2),thioredoxin-1( TRX1),and thioredoxin interaction protein( TXNIP) were analyzed by real-time fluorescent quantitative polymerase chain reaction and Western blot respectively. RESULTS: The MDA level in A549 cells of nano-SiO_2 group increased( P < 0. 05),the T-SOD activity decreased( P < 0. 05),and the mRNA and protein relative expression of NRF2 and TRX1 were up-regulated( P < 0. 05),TXNIP relative expression of mRNA and protein were down-regulated( P <0. 05),when compared with the blank control group and the solvent control group. After intervention with curcumin,with the increased of curcumin concentration,the MDA level in A549 cells decreased,the T-SOD activity increased,the relative expression of NRF2 mRNA and TRX1 mRNA and protein was up-regulated,the mRNA and protein relative expression of TXNIP was down-regulated,and showed a dose-dependent manner( P < 0. 01). CONCLUSION: Curcumin can protect nano-SiO_2-induced oxidative stress in A549 cells. It may activate TRX system by regulating NRF2/antioxidant response elements pathway,exerting an anti-oxidation effect and protecting cells from excessive oxidative damage.