Perspectives of Plant Natural Products in Inhibition of Cancer Invasion and Metastasis by Regulating Multiple Signaling Pathways

Background: Metastasis is often derived from increased invasion and migration of tumor cells, and is the most frequent cause of cancer-associated death. Either the prophylactic or therapeutic treatment of metastatic cancer remains very challenging today by virtue of the complex histopathology and genetic or epigenetic variations. Medicinal scientists had discovered many potential anti-invasive and anti-metastatic compounds from plant materials. However, data on currently available plant-based compounds inhibiting cancer invasion and metastasis is relatively scanty and no published article has been found with updated information in this unique and important aspect. Methods: We obtained relevant information from a structured search of 327 peer-reviewed articles, including both research- and review-based papers, related to the use of plant materials in cancer treatments, particularly for the suppression of invasion and metastasis. Results: We have categorized the plant-based products with anti-invasive or anti-metastatic properties into alkaloids, flavonoids, terpenes, quinones, phenolics, xanthone and sulfur-containing compounds, and complemented with their chemical structures, sources of isolation and biological targets in the present review article. Conclusion: We aim to provide readers a convenient way in reviewing the potential anti-invasive and anti-metastatic plant-based products with links to different mechanistic pathways, and to inspire researchers with updated information for the development of new anticancer remedies.