The Effects of Cyclosporine and Tacrolimus on Gingiva and Alveolar Bone of Rats

Objective: Cyclosporine A (CsA) and tacrolimus (Tac) are immunosuppressive drugs which is frequently used in organ transplantation. CsA can cause various side effects including gingival overgrowth (GO) and osteopenia. Tac has similar side effects to CsA but with different incidences. The aim of the present study was to evaluate and compare the effects of CsA and Tac on GO and alveolar bone resorption in rats. Methods: Sixty mature male rats were randomly and equally allocated into six groups, as follows: Control-I, Control-II, CsA-I, CsA-II, Tac-I and Tac-II. The Control-I and Control-II groups received, subcutaneously, 1 ml/kg 0.9% NaCl, while the CsA-I and CsA-II groups received 10 mg/kg CsA daily, and the Tac-I and Tac-II groups 1.5 mg/kg Tac daily. The Control-I, CsA-I and Tac-I groups were sacrificed on the 16th day and other groups on the 31st day. Histological and histomorphometric analysis of the buccal gingiva and tartrate-resistant acid phosphatase (TRAP) enzyme histochemistry of the alveolar bone were performed in the right mandibular segment of each animal. Results: GO was significantly greater in the groups administered CsA compared to the other groups (P0.05). CsA caused a significant increase in TRAP positivity (P0.05). Conclusions: Our results showed that Tac does not seem to cause GO and alveolar bone resorption. However, the deleterious side effects of Tac on the gingival tissues of rats may be time-related.