Effects of epigallocatechin gallate (EGCG) administration on liver toxicity and cotinine level at cigarette smoke exposed mice

The use of tobacco and its derivatives is widespread all over the world. Oxidant substances in cigarette smoke increase oxidative stress when it enters the body. Epigallocatechin gallate (EGCG) is the most antioxidant and abundant molecule in green tea (Camellia sinensis). The aim of this study was to investigate the effects of increased oxidative stress and liver damage caused by exposure to cigarette smoke in an in vivo experimental design in which antioxidant EGCG was administered acutely and chronically. In our study 84 CD1 male mice were used. Mice were divided into two main groups: acute group (application period lasted 1 day) and chronic group (application period lasted 21 day) and total 12 subgroups. The subgroups were divided into control (exposed to room air) , 2nd control (exposed to cigarette smoke) , 25mg/kg and 50mg/kg only administered EGCG, and last subgoups are administered the same doses of EGCG and smoking. EGCG was administered one time in each day intraperitoneally 30 minutes before entering the smoke chamber. After administration, mice were sacrificed by exsanguination under ketamine/xylazine anesthesia. Liver damage, cigarette smoke exposure and oxidative stress levels were measured by ELISA from blood sample. As a result of the evaluations, it was found that EGCG application significantly increased the levels of GPx and SOD antioxidant enzymes in cigarette smoke groups and did not have a negative effect on liver. In conclusion, the positive effects of EGCG on the antioxidant system and the protection of individuals exposed to cigarette smoke from oxidative stress are thought to be successful, and longer trials and higher doses will play an important role in reinforcing the positive effects.