Effect of Silymarin in Metastatic Colorectal Cancer Patients

Colorectal cancer (CRC) ranks as the third most common cancer globally and second in terms of mortality . Although CRC incidence rates are higher in high-income compared with low-to-middle-income countries (LMICs), mortality is higher in LMICs. Extensive research within the last decade has shown that silymarin can suppress the proliferation of a variety of tumor cells; this is accomplished through cell cycle arrest at the G1/S-phase, induction of cyclin-dependent kinase inhibitors, down-regulation of anti- apoptotic gene products, inhibition of cell-survival kinases and inhibition of inflammatory transcription factors (e.g., Nuclear Factor- kappa B) through suppression of Nuclear Factor- kappa B-regulated gene products, including Cyclooxygenase-2, Lipoxygenase, Tumor necrosis factor and Interleukin-1. Silymarin can also down-regulate gene products involved in the proliferation of tumor cells (Epidermal Growth Factor Receptor, Cyclooxygenase-2), invasion (Matrix metallopeptidase 9), angiogenesis (Vascular Endothelial growth Factor) and metastasis (adhesion molecules). Silymarin was reported to alter the expression of apoptosis-related proteins including BCL2 associated X protein to induce apoptosis in human gastric cancer cells in a concentration-dependent manner. Silymarin has also been shown to sensitize tumors to chemotherapeutic agents through down-regulation of the Multidrug resistance protein and other mechanisms. In addition to its chemo-preventive effects, silymarin exhibits antitumor activity against human tumors in rodents. so we aim to assess the antitumor activity of silymarin in metastatic colorectal cancer patients receiving chemotherapy.