[The system of lipid peroxidation and antioxidant protection of saliva in lung cancer.]

The aim of the study was to study the parameters of the lipid peroxidation system and antioxidant protection in saliva in lung cancer of various histological types. In the case-control study, 740 volunteers participated in the study, which were divided into 3 groups: primary (lung cancer, n = 347), comparison group (non-malignant pulmonary pathologies, n = 178) and control (conditionally healthy, n = 215). Questioning, biochemical examination of saliva, histological verification of the diagnosis were conducted to all participants. The parameters of lipoperoxidation and antioxidant protection are determined spectrophotometrically. Intergroup differences are estimated by a nonparametric criterion. Against the background of lung cancer, the development of oxidative stress is observed, which is manifested in the increase in the level of lipid peroxidation products, as well as in the reduction of antioxidant protection in saliva. It is shown that the activity of the enzymes of the first link of antioxidant protection is significantly reduced (p<0.0001), whereas the activity of salivary peroxidases increases (p = 0.0037). The parameters of non-enzymatic protection vary in different directions: the level of uric acid in lung pathologies decreases (p = 0.0399), whereas albumin concentration increases, under these conditions, it begins to exhibit pro-oxidant properties. Differences between non-small cell and neuroendocrine lung cancer have been revealed by the nature of the dynamics of antioxidant protection indices. In general, the disturbance of the balance of the lipid peroxidation system and antioxidant protection is the result of a disruption in the coordination of immunometabolic processes and indicates a decrease in adaptive reactions of the organism.