Ursolic Acid Suppresses Colorectal Cancer by Down-Regulation of Wnt/β-Catenin Signaling Pathway Activity

Overwhelming evidence points to an abnormally active Wnt/β-catenin signaling as a key player in colorectal cancer (CRC) pathogenesis. Ursolic acid (UA) is a pentacyclic triterpenoid that has been found in a broad variety of fruits, spices, and medicinal plants. UA has been shown to have potent bioactivity against a variety of cancers, including CRC, with the action mechanism obscure. Our study tried to learn more about the efficacy of UA on CRC and its functional mechanism amid the Wnt/β-catenin signaling cascade. We determined the efficacy of UA on CRC SW620 cells with respect to the proliferation, migration, clonality, apoptosis, cell cycle, and Wnt/β-catenin signaling cascade, with assessment of the effect of UA on normal colonic NCM460 cells. Also, the effects of UA on the tumor development, apoptosis, cell cycle, and Wnt/β-catenin signaling axis were evaluated after a subcutaneous SW620 xenograft tumor model was established in mice. In this work, we showed that UA drastically suppressed proliferation, migration, and clonality; induced apoptosis; and arrested the cell cycle at the G0/G1 phase of SW620 cells, without the influence on NCM460 cells, accompanied by weakened activity of the Wnt/β-catenin signaling pathway. Besides, UA markedly deterred the growth of the xenograft tumor, ameliorated pathological features, triggered apoptosis, and arrested the cell cycle in xenograft CRC tissue, by lessening the Wnt/β-catenin signaling cascade. Overall, UA may inhibit the malignant phenotype, induce apoptosis, and arrest the cell cycle of CRC, potentially by attenuating the Wnt/β-catenin signaling axis, providing insights into the mechanism for the potency of UA on CRC.