Anticancer Activity of Sageretia thea Through β-catenin Proteasomal Degradation in Human Colorectal Cancer and Lung Cancer Cells

In this study, we evaluated the effect of branch (STB) and leave (STL) extracts from Sageretia thea on ${\beta}$-catenin level in human colorecal cancer cells, SW480 and lung cancer cells, A549. STB and STL dose-dependently suppressed the growth of SW480 and A549 cells. STB and STL decreased ${\beta}$-catenin level in both protein and mRNA level. MG132 decreased the downregulation of ${\beta}$-catenin protein level induced by STB and STL. However, the inhibition of $GSK3{\beta}$ by LiCl or ROS scavenging by NAC did not block the reduction of ${\beta}$-catenin protein by STB and STL. Our results suggested that STB and STL may downregulate ${\beta}$-catenin protein level independent on $GSK3{\beta}$ and ROS. Based on these findings, STB and STL may be a potential candidate for the development of chemopreventive or therapeutic agents for human colorectal cancer and lung cancer.