Abstract
Colorectal cancer (CRC) is one of the most frequently diagnosed cancers worldwide. Lifestyle-related factors, such as diet, are associated with the development of CRC. Cumulating evidence indicates noticeable chemopreventive effects of phytochemicals on CRC, suggesting that drinking herbal tea potentially reduces the risk of distal colon cancer via its antiproliferative and anti-angiogenic activities. We examine the antitumor effects of nine components frequently found in herbal tea and uncover the underlying molecular mechanism. Among them, the hot water extract of Melissa officinalis (MO) exhibited the highest anticancer activity on CRC cells. We revealed that MO reduced cell proliferation, induced cell cycle arrest at the G2/M phase, triggered caspase-dependent apoptotic cell death, and inhibited cell migration ability by modulating the epithelial-mesenchymal transition in HCT116 CRC cells. To examine the metabolite composition in the MO hot water extract, we applied mass spectrometry-based analysis and identified 67 compounds. Among them, the phenolic compounds, including lignans, phenylpropanoids, and polyketides, are widely found in natural products and possess various bioactivities such as anti-inflammatory, antioxidation, and anticancer effects. The results indicate that herbal tea consumption benefits CRC prevention and management.