The Effects Of Erythromycin On Cigarette Smoke Extract-Induced Reactive Oxygen And 4-HNE Protein In Human U-937 Cells

Objective: To study the effects of erythromycin on cigarette smoke extract (CSE)–induced reactive oxygen species (ROS) and 4-HNE protein in humanu-937cells.Methods: Human u-937cells growth curve was recorded by MTT, cells were divided into three groups:(1) normal control group:(group A, n =6 , incubation for 24, 48, 72h) , (2) CSE group: (CSE0.1%: B1group, n=6,pre-incubation for 24, 36, 48h before adding CSE0.1%24h ; CSE1%: B2group, n=6,pre-incubation for 24, 36, 48h before adding cse1%24h ), (3)CSE + EM :( C1 group,n=6, Pre-incubation EM for 24, 48, 72 h before adding CSE0.1%24h; C2 group,n=6, Pre-incubation EM for 24, 48, 72 h before adding CSE1%24h ). The changes in the intracellular level of ROS were determined by flow cytometry and laser scan microscope using a ROS probe ( 2'-7'dichloro fluorescein diacetate,DCFH-DA). 4-HNE protein were determined by Western blot.Results: Compared to normal control group, the levels of ROS in group B1 and B2 were increased(P<0.01); The levels of ROS was higher in group B1 Compared to group C(1p<0.05,p<0.01); The levels of ROS was higher in group B2 Compared to group C(2p<0.05),but there were no differences in the levels of ROS in group B2 Compared to the group of pre-incubation EM for 24h before adding CSE1%24h. There were decreased in the expression of 4-HNE protein in group of pre-incubation EM for 48h﹑72 h before adding CSE1% 24h compared to group B2.Conclusions: (1) Cigarette smoke extract (CSE) can lead to increace in the levels of ROS and the expression of 4-HNE protein; (2)Erythramycin (EM) can inhibit the levels of ROS and the expression of 4-HNE protein in the cells which led by CSE.