Cytotoxic Effects of Silibinin in Combination with 5-Fluorouracil on HT29 Colorectal Cancer Cells

Colorectal cancer is one of the most common types of cancer in the world, causing many deaths worldwide each year. 5-Fluorouracil is the first choice for the treatment of this type of cancer. Drug resistance and its many side effects are among the weaknesses of this drug. Silibinin, the main bioactive component of silymarin, is originally extracted from Silybum marianum, which is commonly used as an anti-hepatic agent. In recent years, the anticancer effect of silibinin has been observed on different cancer cells. This study aimed to investigate the combined cytotoxic effects of silibinin and 5-fluorouracil on cell viability and p53 expression in the colon cancer HT29 cell line.

Survival of HT29 cells was evaluated by the MTT method after 48 hours of treatment with different concentrations of silibinin and 5 fluorouracil alone and in combination. The expression level of the P53 protein was measured by Western blot method.

Silibinin and 5-fluorouracil significantly inhibited HT29 cell survival in a dose-dependent manner. The simultaneous use of silibinin and 5-fluorouracil showed that silibinin enhances the cytotoxic effects of 5-fluorouracil. In addition, 100 μg/ml silibinin enhanced the impact of 100 μM 5-fluorouracil on P53 protein expression.

This study suggested that silibinin-5-fluorouracil combination may be a valuable candidate for colon cancer patients. Of course, further studies are needed to reach definitive conclusion.