歯周病と抗酸化物質

Reactive oxygen species (ROS), which include super oxide (O2-・), hydroxyl radical (HO・), singlet oxygen (1O2) and hydrogen peroxide (H2O2), are products of normal cellular metabolism. ROS are well recognized for playing a dual role as both deleterious and beneficial effects to living systems.
The harmful effects occur in biological systems when there is a overproduction of ROS on one side and a lack of enzymatic or non-enzymatic antioxidants on the other side. Furthermore, oxidative stress results from the metabolic reactions which use oxygen and represents a disturbance in the equilibrium status of antioxidants in living organisms. The excess of ROS can damage proteins, cellular lipids, and DNA inhibiting their normal function. Therefore, oxidative stress has been implicated in a number of human diseases as well as periodontitis. Recently, clinical studies have noted that the patients of periodontitis have elevated blood levels of oxidative stress compared to periodontally healthy subjects in the cross sectional design. Additionally, the increased oxidative stress is significantly associated with the progression of periodontitis. In longitudinal study, periodontal treatment decreases oxidized low density lipoprotein levels and total oxidative status in the blood of chronic periodontitis patients.
In recent years, many compounds and plant extracts have considerable antioxidant activity, and applied to animal experimental periodontitis models. Investigations provided their possibility for preventive effects on periodontitis. For example, polyphenol including flavonoid revealed both antioxidant and anti-inflammation effect, suppressing the progression of periodontitis by decreasing gingival oxidative stress. In particular, rats were given resveratrol as drinking water and experimental periodontitis was induced in our study. As a result, resveratrol intake relieved alveolar bone resorption and activated the Sirtuin1 / AMP-activated protein kinase and the nuclear factor E2-related factor 2 / antioxidant defense pathways in inflamed gingival tissues. Moreover, resveratrol improved the systemic levels of 8-hydroxy-2’-deoxyguanosine, dityrosine, nitric oxide metabolism, nitrotyrosine, and proinflammatory cytokines. We concluded that oral administration of antioxidants could prevent the progression of experimental periodontitis and improve systemic oxidative stress.