Effects of vitamin C intake on gingival oxidative stress in rat periodontitis

• Published in: Free radical biology & medicine 2009-01, Vol.46 (2), p.163-168
• Main Authors: Tomofuji, Takaaki, Ekuni, Daisuke, Sanbe, Toshihiro, Irie, Koichiro, Azuma, Tetsuji, Maruyama, Takayuki, Tamaki, Naofumi, Murakami, Jun, Kokeguchi, Susumu, Yamamoto, Tatsuo
• Format: Article
• Language: English
• Subjects: Animal studies; Animals; Ascorbic Acid - administration & dosage; Ascorbic Acid - blood; Ascorbic Acid - physiology; Deoxyguanosine - analogs & derivatives; Deoxyguanosine - genetics; Deoxyguanosine - metabolism; DNA, Mitochondrial - analysis; Free radicals; Gene Expression Regulation - drug effects; Glutathione - analogs & derivatives; Glutathione - genetics; Glutathione - metabolism; Interleukin-1alpha - genetics; Interleukin-1alpha - immunology; Interleukin-1alpha - metabolism; Interleukin-1beta - genetics; Interleukin-1beta - immunology; Interleukin-1beta - metabolism; Male; Osteoclasts - drug effects; Osteoclasts - pathology; Osteoclasts - physiology; Oxidative stress; Oxidative Stress - drug effects; Oxidative Stress - physiology; Periodontitis; Periodontitis - pathology; Periodontitis - physiopathology; Periodontitis - prevention & control; Rats; Rats, Wistar; RNA - analysis; Vitamin C
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2008.09.040

Increased levels of oxidative stress due to excessive production of reactive oxygen species are involved in the pathogenesis of periodontitis. Studies suggest a negative association between plasma vitamin C level and the severity of periodontitis. We hypothesized that increases in plasma vitamin C levels after vitamin C intake might clinically reduce gingival oxidative stress in a rat periodontitis model. A ligature was placed around rat mandibular molars for 4 weeks to induce periodontitis, and the rats were then given drinking water with or without 1 g/L vitamin C for 2 weeks after the ligature was removed. The periodontitis-induced rats showed a 149% increase in 8-hydroxydeoxyguanosine level and a 40% decrease in reduced:oxidized glutathione ratio in gingival tissue. Vitamin C intake induced a 175% increase in plasma vitamin C level, resulting in an improvement in the gingival 8-hydroxydeoxyguanosine level (decreased) and in the reduced:oxidized glutathione ratio (increased). Furthermore, in ligature-induced periodontitis lesions, gene expression encoding inflammation, including interleukin-1α and interleukin-1β, was more than twofold down-regulated by vitamin C intake. The results suggest that systemic administration of vitamin C could be clinically beneficial in improving periodontitis-induced oxidative stress by down-regulating inflammatory gene expression.