MNU ile indüklenmiş meme karsinogenezi modelinde postmenepozal dönemde kullanılan kimyasal ajanların kemopreventif özelliklerinin kıyaslanması ve kimyasal ajanlara alternatif olarak Anadolu poleninin ve Trianthema portulacastrum Linn. (Bishkhapra) kemoprevantif özelliğinin araştırılması ve kimyasal ajanlar ile kıyaslanması

Tamoxifen, which is used to prevent the formation of breast cancer, is the only agent used today in both pre-menopausal and post-menopausal periods. However, tamoxifen use has a serious side effect profile such as thromboembolic events and increased risk of endometrial cancer. Therefore, recommending the use of tamoxifen for chemoprevention to the risky group for breast cancer in the post-menopausal period requires a cost-benefit calculation, especially in the group with overweight and morbid diseases. Anastrozole and letrozole, which are used in adjuvant treatment of breast cancer in the post-menopausal period, are known to reduce contralateral breast cancer by 40% in randomized studies. However, the comparison of tamoxifen, anastrozole and letrozole for chemoprevention is not available in the literature. For this purpose, we aimed to compare these three chemical agents in female Sprague-Dawley rats with bilateral oophorectomy in MNU-induced breast cancer chemoprevention model. At the same time, this study will be valuable for the literature since it will be the first time to compare the chemoprevention properties of natural agents with chemical agents by forming additional groups in flavonoids and propolis, whose effectiveness has been proven in the breast cancer chemoprevention model in the literature. For this purpose, chemical and natural agents that we used for chemoprevention in our experimental groups in our experimental groups will be given orally (5 experimental groups, each consisting of 10 rats) and will continue to be given orally every day after MNU application (Day 0), for a total of 17 weeks. Tumor sizes and number of animals with tumors will be noted twice a week and compared with the control MNU group. In order to solve the mechanism of chemoprevention, lipid peroxide and protein oxidation/glycation products, antioxidant system elements, mRNA and miRNA levels in both serum and tumor tissue were examined by examining their effects at the molecular level, whether the extracts applied as a result of our study showed chemoprevention effects, if such an effect, lipid levels and prooxidant levels were determined. It will be investigated whether changes in antioxidant balance contribute to this effect. At the same time, the tumor regression response of the agents whose chemoprevention properties are investigated, if any, will be evaluated pathologically and for this purpose, tissue KI-67 expression percentage will be determined.