Combinational effect of Paclitaxel and Clotrimazole on human breast cancer: Proof for synergistic interaction

Study was aimed to determine the anti-cancerous co-effect of paclitaxel (PAX) with clotrimazole (CLZ) on breast cancer cells and to explore the mechanism involved. Cell viability was evaluated through MTT assay followed by CompuSyn simulations to evaluate, whether the effect of PAX and CLZ in combination was additive, synergistic or antagonistic. Nuclear morphology was examined through DAPI/PI staining and AO/EtBr staining. Level of H2O2 and NO were evaluated to detect reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation as an effect of drug treatment. Comet assay was performed to determine genotoxicity followed by the analysis of cellular glucose uptake. Cell viability assay and CompuSyn simulations confirms synergistic effect of combination at low doses of PAX-12.5 nM and CLZ-25 μM (PACL) against MCF-7 and MDA-MB-231 cells, with minimal effect on normal HEK-293 cells. We observed significant nuclear damage with PACL treated cells through DAPI/PI and AO/EtBr staining, further confirmed by comet assay, where significant DNA damage was observed in MCF-7 (50%) and MDA-MB-231 (73%). NO level increased by 2.6 fold (MCF-7) and 2.4 fold (MDA-MB-231) and H2O2 level also surged by 4.5 fold for both the cell line as an aftermath of PACL treatment. Interestingly, PACL exhibited glucose uptake upto 15% and 20% in MCF-7 and MDA-MB-231 cells respectively. These findings suggest that, PACL acts synergistically against breast cancer cells and its potential can be attributed to increased oxidative stress, reduced glucose uptake and enhanced genotoxicity.

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