title: Oxidative and antioxidative mechanisms in oral cancer and precancer: a review.
abstract: Development of cancer in humans is a multistep process. Complex series of cellular and molecular changes participating in cancer development are mediated by a diversity of endogenous and exogenous stimuli and important amongst this is generation of reactive oxygen species (ROS). Reactive radicals and non-radicals are collectively known as ROS. These can produce oxidative damage to the tissues and hence are known as oxidants in biological system. Many researchers have documented the role of ROS in both initiation and promotion of multistep carcinogenesis. To mitigate the harmful effects of free radicals, all aerobic cells are endowed with extensive antioxidant defence mechanisms. Lowered antioxidant capacity or the oxidant-antioxidant imbalance can lead to oxidative damage to cellular macromolecules leading to cancer. Oral cavity cancer is an important cancer globally and tobacco is the primary etiological factor in its development. Tobacco consumption exposes the oral epithelium to toxic oxygen and nitrogen free radicals that can affect host antioxidant defence mechanisms. Elevated levels of ROS and Reactive Nitrogen Species (RNS) and lowered antioxidants are found in oral precancer and cancer. Protection can be provided by various antioxidants against deleterious action of these free radicals. Treatment with antioxidants has the potential to prevent, inhibit and reverse the multiple steps involved in oral carcinogenesis. This review is an attempt to understand the interesting correlation between ROS and RNS mediated cell damage and enzymatic and non-enzymatic defence mechanisms involved in oral cancer development and its progression and the use of antioxidants in oral cancer prevention and treatment.
authors.affiliation: Dept of Oral Pathology & Microbiology, Yerala Dental College and Hospital, Kharghar, Mumbai 410 210, India. Electronic address: kordesheetal@yahoo.co.in.
authors.forename: Sheetal Korde
authors.initials: SK
authors.lastname: Choudhari
authors.affiliation: Dept of Oral Pathology & Microbiology, Sharad Pawar Dental College, Sawangi, Wardha, Maharashtra 442 001, India. Electronic address: minal53@yahoo.com.
authors.forename: Minal
authors.initials: M
authors.lastname: Chaudhary
authors.affiliation: Dept of Oral Pathology & Microbiology, Sharad Pawar Dental College, Sawangi, Wardha, Maharashtra 442 001, India. Electronic address: gadbail@yahoo.co.in.
authors.forename: Amol R
authors.initials: AR
authors.lastname: Gadbail
authors.affiliation: Dept of Oral Pathology, VSPM Dental College and Hospital, Nagpur, Maharashtra 440 019, India. Electronic address: appu4in@yahoo.co.in.
authors.forename: Aparna
authors.initials: A
authors.lastname: Sharma
authors.affiliation: Dept of Oral Pathology & Microbiology, Modern Dental College & Research Centre, Gandhi Nagar, Indore, Madhya Pradesh 453112, India. Electronic address: satyajitraje@gmail.com.
authors.forename: Satyajit
authors.initials: S
authors.lastname: Tekade
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D063646:Carcinogenesis; D006801:Humans; D009062:Mouth Neoplasms / Q000378:metabolism*; D018384:Oxidative Stress; D011230:Precancerous Conditions / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species
keywords: Antioxidants; Cancer biomarkers; Enzymatic antioxidants; Free radicals; Head and neck cancer; Non-enzymatic antioxidants; Oral cancer; Oral carcinogenesis; Oral precancer; Oxidants; Oxidative damage; Oxidative stress; Potentially malignant disorders; Reactive nitrogen species; Reactive oxygen species