Danggui Buxue Tang potentiates the cytotoxicity of 5‐fluorouracil on colorectal adenocarcinoma cells: A signaling mediated by c‐Jun N‐terminal kinase

Abstract Danggui Buxue Tang (DBT) is a well‐known Chinese herbal recipe often prescribed in clinical treatment for menopausal and cardiovascular symptoms. 5‐Fluorouracil (5‐FU) is a chemotherapy drug that treats several cancers; however, it causes severe adverse effects and multidrug resistance. Combining natural medications can reduce the side effects of 5‐FU use. Hence, we aimed to determine the role of DBT in strengthening the anticancer capabilities of 5‐FU in a cultured colorectal adenocarcinoma cell line (HT‐29 cell) and xenograft nude mice. HT‐29 cells cultured with DBT did not exhibit cytotoxicity. However, co‐administration of DBT with 5‐FU significantly increased apoptosis and the expression of apoptotic markers. The inhibition of proliferation induced by DBT and 5‐FU was shown to be mediated by c‐Jun N‐terminal kinase signaling. In addition, the potentiation effect of 5‐FU and DBT was demonstrated in reducing tumor size, expressions of Ki67 and CD34 in HT‐29 xenograft mice. This finding suggests that DBT can work with 5‐FU as a novel chemotherapeutic strategy for treating colon cancer.