Effects of alpha‑tocopherol on gingival expression of inducible nitric oxide synthase in the rats with experimental periodontitis and diabetes

Abstract

Background: The aim of this study was to investigate effects of α‑tocopherol and/or insulin on the number of gingival inducible nitric oxide synthase (iNOS) positive cells in rats with experimental periodontitis with or without streptozotocin (STZ)‑induced diabetes.

Materials and Methods: A total of 60 Sprague‑Dawley rats were divided into three groups: Group I: The group without diabetes; Group II: The group with STZ‑induced diabetes; Group III: The group with STZ‑induced diabetes receiving insulin therapy. All animals received anesthesia, and 3/0 silk suture was inserted around the mandibular molar teeth. All groups were divided into subgroups receiving saline (Groups IA, IIA, IIIA) and α‑tocopherol injection (Groups IB, IIB, IIIB). After a period of 3 weeks, all rats were sacrificed, and the number of gingival iNOS positive cells was analyzed using image analysis software.

Results: Applying α‑tocopherol suppressed the number of gingival iNOS positive cells in Groups IB, IIB, and IIIB compared to application of saline (Groups IA, IIA, and IIIA) (P < 0.05). Numbers of gingival iNOS positive cells were found to be similar in the Groups I and III (P > 0.05).

Conclusions: Within limitations of the current study, this is the first study one may suggest that α‑tocopherol may reduce oxidative damage in the gingiva of the rats with periodontitis with or without STZ‑induced diabetes and increase effects of insulin.

Keywords: Diabetes, experimental periodontitis, inducible nitric oxide synthase, α‑tocopherol