The <i>In Vitro</i> and <i>In Silico</i> Assessment of the Cytotoxic Effect of Daidzein Alone or in Combination with 5-Fluorouracil on Human Colorectal Adenocarcinoma Cell Line Caco-2

We aimed to evaluate the cytotoxic effect of daidzein alone and in combination with 5-fluorouracil (5-FU) on Caco-2 cells and investigate potential interactions between daidzein and 5-FU with apoptosis-related tumor necrosis factor-related apoptosis-inducing ligand receptor-2, tumor necrosis factor -alpha receptor-1 and Interferon gamma receptor-1. In this study, we used trypan blue and MTT assays to evaluate the cytotoxic effect of daidzein and the effect of daidzein on the amount of substance P released from the cells using the ELISA method. We utilized the ligand-protein molecular docking method for our <i>in-silico</i> assessments. According to our cytotoxicity experiment results, daidzein decreased the proliferation of Caco-2 cells. It should be pointed out that our ELISA test results daidzein and 5-FU increase the level of Substance-P (SP), a proinflammatory cytokine released by Caco-2 cells. Based on our <i>in-silico</i> results, daidzein interacted with all three apoptosis-related receptors on the membrane of Caco-2 cells to a better extent than 5-FU. In sum, although daidzein increases the amount of SP, it is a compound that has significant cytotoxic effect on colon cancer cells and promise as a potential therapeutic agent for the treatment of colon cancer.