Role of immune and metabolic processes in pathogenesis of the development of chronic periodontitis and pneumonia and correction of their impairment with quercetin

Abstract

Chronic periodontitis is one of the most common diseases in dental practice, which shows annual tendency to increase. Nowadays, mechanisms of the formation of this pathology have been substantially studied. However, chronic periodontitis often occurs in combination with a concomitant pathology, in particular, pneumonia. Mechanisms of their formation under conditions of combined pathology and the role of the immune system have not been studied completely, prompting topicality of this research. The results of investigation of the peculiarities of changes in phagocytic leukocyte activity, indices of immune status in the blood, prooxidant and oxidant systems in the periodontium and lungs of guinea pig males in early (6th and 10th days) and late (20th day) periods of chronic periodontitis and in combination with experimental pneumonia have been presented in the article. It has been shown that early and late periods of chronic periodontitis formation, as well as in combination with experimental pneumonia pathology were characterized by increased phagocytic leukocyte activity, which was manifested by an increase (p<0.05) in phagocytic index in the blood, phagocytic number, nitroblue tetrazolium test, especially in late period of the disease. It has been proven that impairment of the balance between cell-mediated (decrease in T-lymphocyte level) and humoral (increase in B-lymphocyte level and circulating immune complexes (CIC)) immunities plays a significant role in pathogenesis of chronic periodontitis. It has been established that a combined pathology in early period of formation was accompanied by a depressive dynamics of cell-mediated immunity with further reduction (p<0.05) of T-lymphocyte level in late period. However, elevation (p<0.05) of B-lymphocyte and CIC levels was detected both in early and in late periods of combined pathology development. Intensification of lipid peroxidation processes has been shown under conditions of antioxidant system inhibition in the lungs and periodontium, especially on the 10th and 20th days of chronic periodontitis development individually and in combination with experimental pneumonia. Administration of quercetin resulted in reduction of phagocytic leukocyte activity, B-lymphocyte level, CIC, the level of conjugated dienes, malonic dialdehyde in the lungs and periodontium, increase in T-lymphocyte level in the blood and activity of superoxide dismutase, catalase in chronic periodontitis and experimental pneumonia.