THE IMMUNOMODULATORY EFFECT OF FENNEL OIL IN MAINSTREAM CIGARETTE SMOKE EXPOSED RATS
Amal Attia El-Morsy Ibrahim
Department of Zoology, Women's Faculty for Arts, Education and Science, Ain Shams University, Egypt
Smoking is a major cause of a variety of adverse health effects, including lung cancer. The exposure to cigarette smoke (CS) significantly increases lung tumor incidence which is thought to be related in part to the genotoxic activities of the chemicals associated with smoke. Little is known about the role of NK cells in the development of lung disease as a result of cigarette smoke exposure. Because of the role of NK cells in the onset and progression of autoimmunity, a great deal of attention has been focused on the objective to enhance NK cell function in order to normalize its defects. The present study was conducted to determine the immunomodulatory effect of administration of fennel oil (FO) in rat lung and on the expression of CD56, a NK subset. Rats were whole-body exposed 2 h/day, 6days/week for 30 days to cigarette smoke. The histopathological, ultrastructure and histochemical changes in lung tissues were reported in cigarette smoke exposed rats with or without FO administration and compared with control and fennel oil treated groups. The presence of NK cells were investigated in all groups. Sections from lung tissues of CS exposed rats showed enlargement of air spaces, air spaces filled with inflammatory cells in the form of eosinophils, lymphocytes, monocytes and detached elastic fibres; appearance of the nucleus of pneumocyte II cells with irregular borders and increase in the primary and secondary lysosomes. The study revealed increase in mucin-positive material and increased expression of CD56 scattered in the pulmonary tissue and in the lining cells of bronchioles. The data revealed that the antioxidant effect of FO resulted in improvement in lung tissue induced lesions besides its immunomodulatory effect against increase in CD56 expression.