Increased salivary level of 8-hydroxydeoxyguanosine is a marker of premature oxidative mitochondrial DNA damage in gingival tissue of patients with periodontitis

Abstract

Introduction: Oxidative stress may contribute to the pathogenesis of periodontitis. However, the detailed molecular mechanism remains unclear. Both 8-hydroxydeoxyguanosine (8-OHdG) and mitochondrial DNA (mtDNA) deletion have been reported as early oxidative DNA damage markers. In this study, 8-OHdG levels in saliva and mtDNA deletions in gingival tissue of patients with chronic periodontitis (CP) were evaluated. Materials and Methods: Gingival tissue and whole saliva samples were collected from 32 patients with CP and 32 healthy control subjects. To determine the clinical condition of each subject, the plaque index, gingival index, clinical attachment level (CAL), and probing depth (PD) were measured. Using the ELISA and polymerase chain reaction methods, the salivary 8-OHdG levels and the 7.4-kbp and 5-kbp mtDNA deletions were examined. Results: The 5-kbp mtDNA deletion was detected in 20 of the 32 periodontitis patients (62.5%), but was not detected in the healthy controls. The mean value of 8-OHdG in the saliva of the periodontitis patients with deleted mtDNA was significantly higher than in the patients with non-deleted mtDNA (p<0.01). Also, significant correlation was found between the occurrence of the 5-kbp mtDNA deletion and salivary 8-OHdG levels (p<0.01). Similar correlations were detected between salivary 8-OHdG levels and age, PD, and CAL (p<0.01, p<0.05). Conclusion: Increased oxidative stress may lead to premature oxidative DNA damage in the gingival tissue of periodontitis patients and the salivary 8-OHdG level may signify premature oxidative mtDNA damage in diseased gingival tissue.

Assessment of Hematotoxicity and Genotoxicity among paint Workers in Assiut Governorate: a case control study

“…The resultant damage may be a significant source of mutations that lead to cancer and other human diseases (Lobo et al 2010). Measurement of (8-OHdG) is a highly sensitive assay for oxygen free radical damage to DNA (Canakci et al 2009;Valavanidis et al 2009). This biomarker has been used to estimate the DNA damage in humans after exposure to cancer-causing agents, such as heavy metals, and polycyclic aromatic hydrocarbons (Bulat et al 2008).…”

Gingival crevicular fluid oxidative stress level in patients with periodontal disease and hyperlipidemia

“…10,11 Moreover, these OS-related mediators have frequently been associated with inflammatory responses, specifically in relation to chronic periodontitis (CP). 1 When ROS attacks proteins and lipids, a series of nonenzymatic reactions occur to produce a large variety of intermediate and end products.…”

Periodontal Disease and Nuclear and Oxidative DNA Damage

“…On the other hand, 8-OHdG level has been studies in oral pathologies, including periodontal disease [25,[32][33][34][35] and oral cancer [36]. As described above, in periodontitis OxS because of the formation of ROS, which is stimulated by neutrophils, produce damage of the bonesupporting tissues.…”

“…Elevated levels of 8-OHdG from cancer patients compared with healthy subjects have been observed in lung cancer [37], basal cell carcinoma [38], colorectal cancer [39], bladder cancer [40], and renal cell carcinoma [41]. With respect to periodontitis, published data on oxidative damage to DNA have been reported by many authors around the world who investigated 8-OHdG levels in the saliva of periodontitis patients [4,25,33,34]. These studies demonstrated that salivary levels of 8-OHdG in samples from periodontitis patients were significantly higher than those from periodontally healthy controls and indicated that salivary 8-OHdG levels may be a useful marker for disease activity and may be indirectly reflect disease severity parameters [4,25,33,34].…”