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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Celecoxib, Comet Assay, Cyclooxygenase 2 Inhibitors, DNA Damage, Head and Neck Neoplasms, Humans, Hydrogen Peroxide, Lactones, Laryngitis, Leukoplakia, Mouth Mucosa, Oxidative Stress, Pharynx, Precancerous Conditions, Pyrazoles, Sulfonamides, Sulfones.
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Do cOX-2 inhibitors celecoxib and rofecoxib prevent oxidative DNA fragmentation? Context: Cyclooxygenase (COX) is the key regulatory enzyme in prostaglandin (PG) synthesis and is up-regulated in many premalignant and malignant lesions. The aim of this study was to investigate the in vitro DNA protective or damaging effects of COX-2 inhibitors using the single-cell gel electrophoresis (Comet) assay. Cells from miniorgan cultures of pharyngeal mucosa from 30 patients were incubated once or five times with the COX-2 inhibitors celecoxib and rofecoxib. After treatment with H2O2, DNA fragmentation was determined. DNA strand-breaks were significantly reduced in cells pre-incubated with COX-2 inhibitors. Repeated incubation with celecoxib showed the strongest effect. This direct influence on DNA repair could be excluded by implementing DNA repair steps into the Comet assay.
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The findings suggest that, in addition to the known influence of COX-2 inhibitors on immune surveillance, neo-angiogenesis and cell proliferation, these substances may express a direct antimutagenic effect in conditions of oxidative stress. Final Decision: yes