Abstract: Nicotine addiction is an important health problem increasing medical morbidity and mortality, Total number of deaths due to tobacco in a single year outweigh total numbers of death due to AIDS, Accidents, Alzheimers, Cancer, Diabetes, Hepatitis, Leukemia, meningitis, Murders and Suicides al together. Smoking prevalence among adolescents has risen significantly since 1990. 

Abstract: Breast cancer is the most frequently diagnosed cancer and the first leading cause of cancer death in females worldwide. Ginkgo biloba, the ginkgo tree or Maidenhair tree is the oldest living tree, with a long history of use in traditional Chinese medicines. Antioxidative effect of ginkgo extract was demonstrated but there have been very limited studies on the anti-proliferative activity of Ginkgo biloba extract. The aim of this study is to evaluate anti-proliferative effects of alcoholic and aqueous ginkgo extracts on human breast cancer cell line (MCF-7). MTT assay were performed using AGE and AQGE concentration of 5, 25,250,500,1000,2500 ,5000μg/ml in time intervals of 24, 48 and 72 h. Our results showed the highest concentration (5000 μg/ml) of AGE and AQGE had an anti-proliferative effects at in 24, 48 and 72 hours of incubation(AGE IC50 24h =2143.3±235.88μg/ml, r²⁼0.912, AQGE IC50 24h =2470±352.69μg/ml, r²⁼0.904).  AGE and AQGE showed a significant cytotoxicity effect in compare to control group in MCF-7 cell line. Anti-proliferative effect of Ginkgo extract revealed this fact that AGE and AQGE could have cell cytotoxicity characteristics beside its cytoprotection mechanisms.