Effect of sinomenine on the proliferation and apoptosis of THP-1 cell

Objective To observe the effect of sinomenine (SIN) on the proliferation and apoptosis of THP-1 cell induced by lipopolysaccharide (LPS).Methods THP-1 cells induced by LPS(1 mg/L,2 h) were divided into four groups and cultured with high,middle and low concentration of SIN and control solution for 24 hours,respectively. The cell proliferation was measured by MTT assay. The apoptotic index was detected using flow cytometry with propidium iodide (PI) staining and the apoptotic level was examined under a fluorescent microscope with acridine orange (AO)/ ethidium bromide (EB) staining. Results Compared to that in the control group,the cell proliferation in high and middle concentration of SIN groups was decreased significantly (P 0.01 and P 0.05,respectively). Flow cytometry showed an elevated apoptotic rate in the three different concentrations of SIN groups. Apoptotic changes including nuclear fragmentation and cell membrane injury were observed in cells treated with SIN. Conclusion The therapeutical effect of SIN on rheumatoid arthritis (RA) and the immunosuppression of SIN are probably activated by inhibiting the proliferation of monocytes and then increasing apoptosis.