Mechanism of azithromycin treatment on gingival overgrowth

Azithromycin is effective for the remission of cyclosporins A-induced gingival overgrowth (CIGO) in persons who have undergone renal transplant. To explain its mechanism in alleviating the clinical symptoms of these indrvduals, we examined the effect of azithromycin on cell proliferation and collagen turnover modified by cyclosporin A in human gingival fibroblasts from healthy persons and from persons who had undergone renal transplant. Cyclosporin A-induced proliferation of renal transplant fibroblasts and normal fibroblasts was Inhibited by azithromycin. Azithromycin elevated the reduced metalloprotelnase (MMP)-1 and MMP-2 activities in eyclosporine A-treated renal transplant fibroblasts and normal fibroblasts. In eyclosporine A-treated renal transplant fibroblasts, azithromycin blocked the accumulation of total collagen in culture media and the increase in type I collagen mKNA level, but recovered the reduced MMP-2 mRNA level to the control. These results suggest that azithromycin may improve CIGO by blocking eyclosporine A-induced cell proliferation and collagen synthesis, and by activating MMP-2 In gingival fibroblasts of persons with eyclosporine A-Induced gingival overgrowth.