en انكولوژي Oncology پژوهشي Research <div style="text-align: justify;"><span style="font-size:11pt"><span style="line-height:normal"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Background & Objective:</span></span></i></b><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times=""> Breast cancer is one of the most common cancers in the world. Treatment methods for this disease have been with poor results. In recent years, more attention has been paid to stem cells due to their cytotoxic properties. According to previous results, the effect of nanoquercetin on breast cancer cells in this study was used concomitantly with doxorubicin, which is a chemotherapy drug and in some patients has therapeutic resistance. </span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Materials & Methods:</span></span></i></b><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times=""> The above study was performed on MCF7 and BT474 human breast cancer cells. Quercetin was synthesized, then different concentrations of 10, 20, 40, 80 and 160 of quercetin and 1, 2.5, 5 and 10 &mu;g/ml of doxorubicin were prepared and two cell lines were treated for 24 h. MTT test was used to determine cell viability and flow cytometry test was used to determine the extent of apoptosis in both cell lines.</span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Results:</span></span></i></b><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times=""> The results showed that MCF7 and BT474 cells that were affected by quercetin and doxorubicin, increasing the concentration of quercetin and doxorubicin decreased the survival of both cell lines within 24 h. The LC50 concentration was calculated for both cells treated with nanoquercetin 40 &mu;g/ml and for doxorubicin doxorubicin (0.1 mg/ml). The results also showed that in both cell lines, an increase in cellular apoptosis occurred after incubation with quercetin and then incubation with doxorubicin. </span></span></span></span></span><br> <span style="font-size:11pt"><span style="line-height:normal"><span sans-serif="" style="font-family:Calibri,"><b><i><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times="">Conclusion:</span></span></i></b><span style="font-size:10.0pt"><span new="" roman="" style="font-family:" times=""> Comparison of doxorubicin (DOX), quercetin (QU) and quercetin and doxorubicin (QU-DOX) groups with controls shows that with the presence of quercetin-doxorubicin, it had a greater inhibitory effect on cancer<b> </b>cells.</span></span></span></span></span><br> &nbsp;</div> Quercetin, Doxorubicin, MCF-7, BT474, Breast Cancer 292 301 http://jabs.fums.ac.ir/browse.php?a_code=A-10-2670-3&slc_lang=en&sid=1 Fatemeh Sorayabin Mobarhan فاطمه ثریابین مبرهن 100319475328460026546 100319475328460026546 No Department of Biology, Roudehen Branch, Islamic Azad University, Roudehen, Iran گروه زیست شناسی، واحد رودهن، دانشگاه آزاد اسلامی، رودهن، ایران Maryam Teimouri مریم تیموری teimourimaryam93@gmail.com 100319475328460026547 100319475328460026547 Yes Department of Biology, Roudehen Branch, Islamic Azad University, Roudehen, Iran گروه زیست شناسی، واحد رودهن، دانشگاه آزاد اسلامی، رودهن، ایران Mehdi Pooladi مهدی پولادی mehdi.pooladi7@gmail.com 100319475328460026548 100319475328460026548 No Department of Biology, Faculty of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran گروه زیست شناسی، دانشکده علوم پایه، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران