Antioxidant Effect of Mangiferin and its Potential to be a Cancer Chemoprevention Agent

It is generally recognized that oxidative stress is one of the most common cause of carcinogenesis. Many studies have demonstrated that oxidative stress can cause the over-expression of growth factors or their receptors, mutations of oncogenes and anti-oncogenes, excessive activation of tyrosine kinases or serine/threonine kinases, and activation of some kinds of transcription factors including AP1, NF-κB, HIF-1, NFATs. All these events have been demonstrated to be involved in tumor formation via regulating the cellular proliferation, differentiation, survival, apoptosis and tumor angiogenesis. It is also demonstrated that oxidative stress can cause DNA damages, such as DNA bases modification, base-free sites, strand breaks and DNA–protein cross-links, which are associated with carcinogenesis via leading to not only genomic instability but also disorders of transcription, replication and signal transduction pathways. Mangiferin is the main active ingredient of vimang (an aqueous extract of Mangiferia indica L., which is traditionally used as an antiinflammatory, analgesic and antioxidant in Cuba). It has been demonstrated that mangiferin could enhance the antioxidant status, decrease the oxygen free radicals (ROS) level and reduce DNA damage in animal models. In addition, some studies reported that mangiferin could reduce carcinogen-induced tumor formation. Its chemopreventive role was associated with the reduction of oxidative stress and DNA damage.