Effect of different bleaching techniques on DNA damage biomarkers in serum, saliva, and GCF

Are Dental Caries Associated with Oxidative Stress in Saliva in Children and Adolescents? A Systematic Review

Background: This systematic review aimed to assess whether dental caries is associated with oxidative salivary stress. Methods: The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, the Cochrane Library, LILACS, OpenGrey, and Google Scholar, without restrictions on the date of publication and language. The acronym PECO was used, in which the participants (P) were children and adolescents exposed (E) to dental caries compared (C) to those without dental caries, with the outcome (O) of modulation of oxidative biochemical parameters. After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract, following the inclusion and exclusion criteria. Then, the papers were read and thoroughly assessed. After selection, the risk of bias assessment and qualitative synthesis were performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. Results: A total of 5790 studies were found, and 30 articles were considered eligible and were included for the qualitative synthesis and the level of evidence assessment. The studies showed an imbalance of the antioxidant and pro-oxidant parameters in individuals with dental caries, with primarily increases in both total antioxidant capacity and lipid peroxidation. Most articles showed a low risk of bias, having comparability as the main issue. When exploring through GRADE, a very low level of evidence was found. Conclusions: It was possible to observe an association between oxidative stress and dental caries, showing a disbalance of antioxidants and pro-oxidants, but the evidence level was still very low.

Thymoquinone: A Review of Pharmacological Importance, Oxidative Stress, COVID-19, and Radiotherapy

Widely consumed worldwide, Nigella sativa (NS) is a medicinal herb commonly used in various alternative medicine systems such as Unani and Tibb, Ayurveda, and Siddha. Recommended for regular use in Tibb-e-Nabwi (Prophetic Medicine), NS is considered one of the most notable forms of healing medicine in Islamic literature. Thymoquinone (TQ), the main component of the essential oil of NS, has been reported to have many properties such as antioxidant, anti-inflammatory, antiviral, and antineoplastic. Its chemical structure indicates antiviral potential against many viruses, including the hepatitis C virus, human immunodeficiency virus, and other coronavirus diseases. Interestingly, molecular docking studies have demonstrated that TQ can potentially inhibit the development of the coronavirus disease 2019 (COVID-19) by binding to the receptor site on the transmembrane serine proteinase 2 (the activator enzyme that attaches the virus to the cell). In addition, TQ has been shown to be effective against cancer cells due to its inhibitory effect by binding to the different regions of MDM2, according to the proposed molecular docking study. Detailed in this review is the origin of TQ, its significance in alternative medicine, pharmacological value, potential as a cancer anti-proliferative agent, use against the coronavirus disease 2019 (COVID-19), and treatment of other diseases.