The increase in the formation of reactive oxygen and reactive nitrogen species of endogenous or exogenous origin causes oxidative stress due to pro-oxidant and antioxidant imbalance that causes cellular damage in metabolism. This can increase inflammation of cells, apoptosis and necrosis, damage to DNA base damage, DNA and protein cross-links, lipid membrane peroxidation, and mitochondrial dysfunction. Antioxidants can be described as a system that protects biomolecules and the organism against the harmful effects of free radicals, reduces or repairs the damage done by reactive oxygen species (ROS) to the target molecule, and this is called antioxidant defense. It is known that the mechanisms caused by the increase in ROS resulting from oxidative stress are positively related to the pathology of many diseases such as cancer, metabolic syndrome, atherosclerosis, malaria, Alzheimer’s disease, rheumatoid arthritis, neurodegenerative diseases and preeclampsia.

Keywords: Chronic periodontitis; Inflammation; Ozone; Periodontal treatment; TGF-β

Objective: To determine the total oxidant status (TOS), total antioxidant status (TAS), and the 8-hydroxy-2′-deoxyguanosine (8-OHdG) levels and their interrelationship in the saliva of children undergoing fixed orthodontic therapy. Materials and Methods: Thirty children were randomly divided into three groups. The attachments were bonded to all of the teeth using three different orthodontic composites: Transbond XT, Kurasper F, and GrenGloo. The salivary levels of TOS, TAS, and 8-OHdG were determined three times, as follows: before treatment (T ₁ ) and at 1 month (T ₂ ) and 3 months (T ₃ ) following appliance placement. All data were statistically analyzed. Results: There were no significant differences in TOS, TAS, and 8-OHdG within the same time periods among the three different orthodontic composites ( P > .05). TAS in all composite groups decreased over time. These decreases were found to be significant for Kurasper F and GrenGloo at the T ₁ –T ₃ and T ₂ –T ₃ time periods ( P < .05). In all composite groups 8-OHdG decreased between T ₁ and T ₂ ( P < .05). However, 8-OHdG in all composite groups increased from T ₂ to T ₃ . These differences in 8-OHdG were significant in Kurasper F and GrenGloo ( P < .05). Conclusions: Fixed orthodontic appliances bonded with the tested composites did not increase the cytotoxicity markers in saliva.

To evaluate the protective effects of Resveratrol (RES) on azoxymethane (AOM)-induced testicular damage using histopathology and biochemical analyses, 28 male rats were randomly divided into four groups. Groups were control, RES, AOM and ARES. At the end of the 7 weeks, following routine tissue processing procedure, testis sections were stained with haematoxylin-eosin and Masson's trichrome. The blood samples were taken for biochemical analysis of testosterone, total oxidative stress, total antioxidant status and oxidative stress index. Degenerative changes in the seminiferous tubules such as atrophy, loss in the number of germ cells and arrested spermatogenic cell, and increase in the connective tissue of the tunica albuginea in the groups with AOM treatment were found. RES treatment (ARES) reduced the number of affected seminiferous tubules significantly (p < .05) compared to AOM alone. The testosterone levels in AOM group were significantly lower than in the control group (p < .05). The total oxidative stress levels were significantly higher in AOM group compared to control group (p < .05). The total antioxidant status levels in ARES group were significantly higher than in the AOM group (p < .05). This study results suggest that an antioxidant like Resveratrol may be useful for decreasing the harmful effects of azoxymethane.