T. Boudieri Extract Potentiates the Effects of Capecitabine Treatment in Human Colon Cancer Cells

Resistance to chemotherapy remains a major challenge for colorectal cancer patients worldwide, hence the persistent need to uncover alternative treatments as well as new adjunct therapies in the fight against cancer. Natural extracts constitute an excellent source of bioactive substances that have a promising potential in that regard, with minimal negative side effects. We have previously demonstrated that both the ethanolic as well as the water extracts of Terfezia boudieri, a black desert truffle abundant in and part of the cuisine of the Mediterranean region, have significant antiproliferative effects against colon cancer cells. Our aim in this study was to investigate if this effect can be translated into one that enhances the efficacy of capecitabine, an antimetabolite used as a first line of treatment drug in colorectal patients. We treated human colon cancer cells HCT-116 with a water extract of T. boudieri that we have prepared and employed the MTT cell viability assay to measure the cell viability at different concentrations of treatment either with the extract alone or in combination with different concentrations of capecitabine vs those with capecitabine alone. The combination index (CI) calculated using the Chou and Talalay's equation as well as the morphological changes observed in the HCT-116 cell line utilizing the Crystal Violet assay showed a clear potential for the extract to act in synergy with capecitabine, enhancing its anti-cancer effects.