Ursolic Acid in Cancer Treatment and Metastatic Chemoprevention: From Synthesized Derivatives to Nanoformulations in Preclinical Studies

Background: Cancer metastasis has emerged as a major public health threat that causes majority of cancer fatalities. Traditional chemotherapeutics have been effective in the past but suffer from low therapeutic efficiency and harmful side-effects. Recently, it has been reported ursolic acid (UA), one of the naturally abundant pentacyclic triterpenes, possesses a wide range of biological activities including anti-inflammatory, anti-atherosclerotic, and anti-cancer properties. More importantly, UA has the features of low toxicity, liver protection and the potential of anti-cancer metastasis. Objective: This article aimed at reviewing the great potential of UA used as a candidate drug in the field of cancer therapy relating to suppression of tumor initiation, progression and metastasis. Methods: Selective searches were conducted in Pubmed, Google Scholar and Web of Science using the keywords and subheadings from database inception to December 2017. Systemic reviews are summarized here. Results: UA has exhibited chemopreventive and therapeutic effects of cancer mainly through inducing apoptosis, inhibiting cell proliferation, preventing tumor angiogenesis and metastatic. UA nanoformulations could enhance the solubility and bioavailability of UA as well as exhibit better inhibitory effect on tumor growth and metastasis. Conclusion: The information presented in this article can provide useful references for further studies on making UA a promising anti-cancer drug, especially as a prophylactic metastatic agent for clinical applications.