Mefenamic acid as a promising therapeutic medicine against colon cancer in tumor-bearing mice

Although radiotherapy is an effective strategy for cancer treatment, tumor resistance to ionizing radiation (IR) and its toxic effects on normal tissues are limiting its use. The aim of this study is to evaluate the anti-cancer effects of mefenamic acid (MEF), as an approved medicine, and its combination with IR against colon tumor cells in mice. Tumor-bearing mice were received MEF at a dose of 25 mg/kg for 6 successive days. The tumor size was measured. In the second experiment, after MEF treatment, tumor-bearing mice locally received an X-ray at dose 6 Gy. Tumor growth and biochemical, histological, and immunohistological assay (caspase-3) were performed. MEF significantly decreased tumor size in mice in comparison to the control group. IR and/or MEF treatment significantly reduced the tumor volume and inhibited tumor growth by 49%, 55%, and 67% by MEF, IR, and MEF + IR groups as compared with the control group. Administration of MEF in combination with radiation had a synergistic effect on enhanced histopathological changes in tumor tissues. MEF treatment in IR exposure mice showed a significant increase in the immunoreactivity of caspase-3 in the colon tumor tissue. MEF has an anti-tumor effect in colon tumor-bearing mice. MEF in combination with IR increased pathological changes and apoptosis in tumor tissues, suggesting that MEF might be clinically useful in the treatment of colon cancer. Graphical abstract