Growth inhibition of HCT116 induced by Thai herbal recipe is mediated via cyclin D1 and CDK4 suppression

Abstract

© 2020 Faculty of Pharmacy. Thai herbal recipe named "Sam Rak" is commonly used in the Northeasthern part of Thailand for treating various malignancies, such as breast, liver, and colon cancers. Previously, we investigated the ED50 of the herbal ethanolic extract on colon cancer cell line, HCT116, and found the significant growth inhibition. Thus, this herbal recipe was further investigated in this study to clarify the underlying mechanisms in HCT116. The clonogenic assay was performed to assure the antiproliferative activity of the herbal recipe at the concentrations of 35 and 70 μg/mL. In addition, the expression of three genes, i.e., CCND1, CDK2, and CDK4, which regulate the cell cycle progression, were also done using a real-time PCR (qPCR). The results showed that the herbal recipe could kill HCT116 cells, as shown in clonogenic assay, especially at day 7. Moreover, with qPCR techniques, the significant downregulation of both CCND1 and CDK4 were demonstrated. CDK2 also showed downregulation, but not significant. We summarized that this three-root herbal recipe could inhibit growth and kill colon cancer cell line, HCT116, in vitro. The mechanisms of action involved in significant suppression of the expression of two genes, CCND1 and CDK4. This study might be useful for the application of this herbal recipe in treating colon cancer in the future.