Efficacy of azithromycin and metronidazole combined therapy on rats' gingival overgrowth induced by cyclosporine-A: An experimental animal study.

Aims: To evaluate the therapeutic efficacy of azithromycin (azm) and/or metronidazole (mtz) on the histopathological features of rats' gingival overgrowth (GO) induced by cyclosporine-A (CsA) in an animal model.
Methods: Ninety male albino rats were divided randomly into six equal groups. The rats of group I received corn oil via gastric feeding for 7 weeks. Group II rats were administered CsA for the same period. Groups III, IV, and V rats received CsA for 6 weeks and simultaneously in the 7th week received a monotherapy of placebo gel, azm suspension, mtz gel, respectively. Group VI rats were handled as groups III, IV, and V and instead received a combined therapy of azm suspension, and mtz gel. Rats were euthanized at the end of the experiment and routine tissue processing was carried out. The obtained specimens were stained with H&E, TGF-β, MMP-1, and IL-6 antibodies.
Results: One-way MANOVA test for TGF-β, MMP-1, and IL-6 revealed an overall significant difference between the different groups ( P  = 0.000). LSD post hoc test for multiple comparisons of TGF-β revealed nonsignificant difference between groups I and VI and between groups IV and V. Nonsignificant difference was found between groups II and III considering the amount of MMP-1 immune expression. In addition, nonsignificant difference was found between groups V and VI regarding the amount of immune expression for IL-6.
Conclusion: Combined therapy of azm suspension and mtz gel significantly improved the histopathological features of CsA-induced GO better than a monotherapy of azm suspension or mtz gel.