Protective effects of ST. john' S wort extract on apoptosis in lung by chronic cigarette smoke

Exposure to cigarette smoke causes a variety of damages to human tissues. Many apoptotic processes play important roles in these hazards. Mechanisms of these damages have not been clearly identified yet. In our study we aimed to investigate the underlying apoptotic mechanisms of the cigarette smoke exposure on mice lung tissues and evaluate potential protective effects of Hypericum perforatumextract. In experimental study, mice (Swiss albino, male, age: 8 weeks) were divided in three groups as control (without cigarette smoke exposure; n=8), cigarette smoke group (n=8) and H. perforatum extract group (with cigarette smoke exposure; n=8; by gavage). The cigarette smoke application continued 7 days in a week during two months. In the end of two months, the mice were killed by cervical dislocation and their lungs were isolated. Lung tissues were studied with ELISA method to determine the levels of determinants of apoptosis namely caspase-3, Bax and Bcl-2. Smoke treatment increased caspase-3 expression and Bax protein levels significantly and decreased Bcl-2 levels in mice lungs. These findings were detected to be reversed with H. perfaratum extract pretreatment. In our study; we showed that cigarette smoke exposure causes apoptosis and this was shown to be blocked by H. perfaratum extract. The study might has a contribution for understanding the underlying pathological mechanisms of lung diseases which were observed more in human with cigarette smokers. Therefore this study provides valuable informations for further studies which should investigate both the potential effect of apoptosis in lung function and protective role of H. perfaratum.