Effect of Methotrexate and Tea Polyphenols on the Viability and Oxidative Stress in MDA-MB-231 Breast Cancer Cells

Abstract

Aim: To determine the effect of tea polyphenols and methotrexate on viability and reactive oxygen species (ROS) in a naturally resistant breast cancer cell line MDA-MB-231. Methodology: MDA-MB-231 cells were selected as a model for methotrexate resistant breast cancer. Drug tests were performed over 72 hours at concentrations 0-100 µM. Pre-treatments were with quercetin (QE) or epigallocatechin gallate (EGCG) for 5 hours followed by methotrexate. Cytotoxicity was measured using the MTT assay or resazurin fluorescence assay. ROS was determined using the 2', 7'-dichlorofluorescein diacetate assay. Intracellular GSH was measured using the monochlorobimane assay. Results: Methotrexate was cytotoxic to MDA-MB-231 cells with IC 50 of 35±4 µM. The IC 50 value was 68±9.4 µM with QE and 83±16 µM for EGCG. The pre-treatment with QE and EGCG lowered the IC 50 for methotrexate by 28% (P =0.009) and 16% (P=0.2027). Intracellular ROS concentrations increased after treatment with methotrexate, QE or EGCG singly and ROS Short Communication

Rationally Designed Micellar Nanocarriers for the Delivery of Hydrophilic Methotrexate in Psoriasis Treatment

“…In contrast, the breast cancer cell line MDA-MB-231 is not sensitive to MTX due to the low expression level of reduced folate carrier, a transmembrane transporter for MTX cell uptake. Therefore, there is no significant inhibition of cell proliferation at low concentration in MDA-MB-231 cells for both free MTX and MTX nanoformulation, with an IC 50 detected around 5 μg/mL, which are also consistent with the literature …”

“…Therefore, there is no significant inhibition of cell proliferation at low concentration in MDA-MB-231 cells for both free MTX and MTX nanoformulation, with an IC 50 detected around 5 μg/mL, which are also consistent with the literature. 50 The hemolytic toxicity of MTX formulations was evaluated after incubation with red blood cells (RBCs) for 0.5 h, 4 h (Figure S5), and overnight. As shown in Figure 5D,E, free MTX, all of the blank Rf-containing TDs, and MTX nanoformulations are inert with ≤3% hemolysis observed at concentrations up to 1000 μg/mL.…”

Effects of Ascorbic Acid, Dehydroascorbic Acid and Methotrexate on Breast Cancer Cell Viability

“…Owusu-Apenten found the IC50 of MTX was 3 that proved to be higher than that of the only study (to our knowledge) that performed the analyses under very similar conditions. Kelly & found the IC50 of MTX was 35 µmol/l after 72 h of treatment using the MTT assay in MDA-MB-231 cells, which is significantly lower than the IC50 of 201.4 µmol/l obtained in this study [31]. Other studies that reported the IC50 of MTX used drug treatments at a shorter time or/and with different cell lines.…”

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“…For example, at low concentrations the poison methotrexate improves viability of breast cancer cell lines. 41 If methotrexate were contaminated with the chemically similar growth promoter, folate, then this might make interpretation of any positive effects of methotrexate difficult to distinguish from the effects of lower concentrations of the contaminant folate.…”