ABSTRACT
Objective To investigate the mechanism of glucocorticoid resistance in patients with systemic lupus erythematosus(SLE) and the effects of Panax Notoginseng Saponins(PNS) on reversing glucocorticoid resistance in lymphocytes. Methods The relevance between P-glycoprotein (P-gp, %) and SLEDAI integrals or clinical effects was analyzed by linear correlation analysis. The lymphocytes from SLE patients were intervened with PNS or verapamil. P-gp of the lymphocytes and Rhodamine 123 (Rh123, %) accumulated in the lymphocytes were assayed by flow cytometry. The percentage of the apoptosis of the lymphocytes stimulated with PNS or verapamil combined with methylprednisolone was identified by double-tagging with Annexin V and propidium iodide (PI) and detected by flow cytometry. Variance analysis or Student's t test was used for statistics. Results The P-gp in the peripheral blood lymphocytes of SLE patients was significantly related to SLEDAI integrals. The difference of P-gp between lymphocytes in the completely remission cases (12.2±2.5)% and lymphocytes in the partial remission or non-effective cases (16.5±4.0)% was statistically significantce. The difference of P-gp and Rh123 between lymphocytes treated with PNS [(11.2±3.1)%,(70.1 ±5.8)% respectively ] and lymphocytes of the control group [ (15.3±2.9)%, (53.9±5.2)% respectively ]was statistically significant. The lymphocytes apoptosis rate in the lymphocytes stimulated with methylprednisone combined with PNS increased significantly compared to the lymphocytes stimulated with methylprednisolone only. Conclusion The action of PNS in suppressing both the expression and the transfer activity of P-gp is possibly the important mechanism to increase the effects of methylprednisolone in inducing lymphocytes apoptosis.