Effect of vitamin C supplementation on periodontal inflammation and oxidative stress in cigarette‐smoke‐exposed rats with periodontitis

This study examined the effects of vitamin C on oxidative stress, antioxidant levels, and periodontal inflammation in a rat model of periodontitis exposed to cigarette smoke. Periodontitis was induced in 30 male Wistar albino rats using ligatures on maxillary second molars. All groups underwent 15 days of smoke exposure, which was then continued for another 15 days in the smoking-only (SO) and smoking + vitamin C. The vitamin C group received 200 mg/kg/day of intraperitoneal vitamin C; the saline group received 0.9% NaCl. On Day 28, rats were euthanized for biochemical and immunohistochemical analyses. The SO group showed significantly elevated cotinine and tumor necrotizing factor-α levels. Reactive oxygen species, thiobarbituric acid reacting substances, and catalase activity were also significantly higher in this group. Vitamin C groups showed lower levels, with no significant differences between them. Ferric-reducing antioxidant power levels in the saline group were significantly higher than in the SO group. Immunohistochemical analysis revealed significant differences in Ki-67 and matrix metalloproteinase-8-positive-stained cells between SO and vitamin C groups. Within the limitations of this model, vitamin C supplementation was associated with reduced oxidative stress and inflammatory responses in smoke-exposed rats with periodontitis. These results suggest vitamin C may modulate host antioxidant defense, though further clinical confirmation is needed.