Bitter Melon Extract (BME) is widely used for the treatment of various diseases worldwide, due to its rich phytochemical and antioxidant content. The well-known anti-cancer drug, Paclitaxel (PAC) plays a major role in the treatment of various cancer types such as ovarian, breast, and lung cancer. Technetium-99m (99mTc) radiolabeled paclitaxel is emerging as an imaging probe for breast cancer in vivo. 99mTc labeled compounds have been attracting more scientific attention since the achievement of earlier researches in Nuclear Medicine. People consume several types of plant origin diet without knowing the interaction with radiolabeled compounds or radiopharmaceuticals.In the current study, we aimed to monitor potential effects of the BME on the uptake of 99mTc labeled Paclitaxel (99mTcPAC) on MCF-7 (ER+) and MDA-MB-231 (ER-) cell lines by using in vitro methods.BME was obtained by extraction of BM seeds by 80% ethanol. PAC was labeled with 99mTc by stannous chloride (SnCl2) as reducing agent. Cytotoxicity and incorporation assays were performed on MCF-7 and MDA-MB-231 cells within the cell culture studies.The uptake value of 99mTc-PAC on MCF-7 cells at 240 minutes was 6.20% and BME treated 99mTc-PAC values was 17.39%.It is observed that BME treatment has a significant effect on uptake of the 99mTc-PAC on MCF-7 cells which is a known estrogen receptor positive breast carcinoma cell line. It is concluded that this effect could be due to the estrogen receptor dependent interaction of BME.