Differential Cytotoxic and Morphological Effects of Curcumin and Etoposide on MCF-7 Breast Cancer Cells

Abstract

Curcumin, a turmeric-derived polyphenol, modulates apoptotic signaling and cell-cycle control, whereas etoposide, a topoisomerase II inhibitor, exerts cytotoxicity by inducing DNA strand breaks. To delineate their relative actions on tumor cell viability, the objective was to directly compare the dose-dependent cytotoxic and anti-proliferative effects of curcumin and etoposide in ER-positive MCF-7 breast cancer cells, quantifying changes in viability and survival across graded concentrations and characterizing attendant morphological alterations. MCF-7 breast cancer cells were seeded at 1 × 10⁴ cells per well in 96-well plates and into two groups (three technical replicates each): control DMSO (100µL), curcumin (31.2, 62.5, 125, 500, and 1000 µg/mL), etoposide (31.2, 62.5, 125, 500, and 1000 µg/mL). Treatments were applied for 72 h at 37°C. Cell viability was quantified by the MTT assay while morphological observations were documented by inverted microscope. Significantly, at the maximum concentration evaluated (1000 µg/mL), both drugs elicited pronounced morphological changes in MCF-7 cells. MTT analysis demonstrated a clear dose-dependent reduction in cell viability. Curcumin therapy diminished viability to 51%, whereas etoposide treatment led to a 75% reduction in viability at the identical quantity (1000 µg/mL). The determined half-maximal inhibitory concentration (IC₅₀) values were 165.4 µg/mL for curcumin and 89.2 µg/mL for etoposide, corroborating the significant cytotoxicity of both therapies.