The Protective Effect Of Nitronyl Nitroxide Radical On Peroxidation Of A549 Cell Resulting From Iron Overload

In recent years,with the increasingly serious environmental pollution,haze weather has been caused much attention.As one of the major carcinogens in air pollution,iron can produce hydroxyl radical(·OH)by Fenton reaction,induce oxidative stress,DNA damage and apoptosis,leading to respiratory disease and cancer.In addition to strengthening our environmental governance,we need to find an effective protective solution.There is still a long distance from the clinical protective effect of drugs to people's expectation,so the development of new protective drugs has become an urgent task of researcher.Nitronyl nitroxide radicals are a kind of stable compounds containing spin single electrons,which exhibit strong ability to remove harmful free radicals from the body.Some studies have found that a small amount of nitroxide can play an effective antioxidant effect.The protective properties of nitroxides on A549 cells will be studied in this paper.We hope it feasible for the nitroxides to become the new anti-oxidative stress drugs in the prevention and treatment for lung diseases.In this paper,NITR-2,4-(OMe)2(abbreviated as NITR)was synthesized and characterized by IR,UV-vis,XRD and elemental analysis.In order to investigate the antioxidant ability of nitronyl nitroxide,the oxidative damaged A549 cells induced by iron overload was used as the model to study the protective effect of NITR.The cells were divided into four groups: normal control(1)group: cultured cells with minimal medium that without serum,used to compared with the dosing group.Ferric ammonium citrate(FAC)group: cultured cells(2)with medium containing 100 ?M FAC,which exhibit oxidative damage because of iron overload.(3)NITR group: cultured cells with medium containing 0.25 ?M NITR,which is used to study whether the cell viability is enhanced.FAC + NITR group:(4)cultured cells with medium containing 0.25 ?M NITR and 100 ?M FAC,which is used to study whether NITR could alleviate the oxidative damage of FAC on A549 cells.In the process of divided experiment,the A549 cell all cultured for 24 houres,and then the cells were collected and tested.The cell viability,cell morphology,intracellular redox level,cell cycle distribution,apoptosis rate and apoptotic protein were detected with MTT,DIPA staining,fluorescence microscopy,flow cytometry and Western Blot.1.NITR nitronyl radicals can enhance cell viability,reduce the number of apoptosis,reduce the FAC damage to A549 cells,.2.The results showed that NITR nitronyl nitroxide radicals could effectively reduce the oxidative damage of A549 cells and enhance the antioxidant capacity of A549 cells.The antioxidant capacity of A549 cells was significantly improved.3.Cell cycle and apoptosis were detected by flow cytometry.NITR nitronyl radicals could alleviate the G2 arrest and decrease the apoptosis of A549 cells.4.Western blot results showed that the expression of protein Bax and DDIT-3 was decreased and the expression of bcl-2 protein was increased with the NITR group A549 cells.The experimental study confirmed that the NITR radical does protect the oxidative damage of A549 lung cells caused by iron overload,which take part in two apoptotic signaling pathways of the mitochondria and endoplasmic reticulum stress.The results provide a strong theoretical reference and experimental basis for the nitroxides as new anticancer drugs.But the determination of the apoptotic signaling pathway requires deeper research about the mechanisms,which is the focus of our future work.