Scientific research into the health benefits of xanthones from mangosteen has been conducted since the 1970s and, although there is still much more work to be done, the results thus far are very promising. Mangosteen is a complex research subject because it contains over 40 xanthones. Choices, therefore, need to be made regarding which particular xanthone should be the focus of any given study. Two of the most studied xanthones are alpha-mangostin and gamma-mangostin.
Both of these compounds have been shown to be very effective anti-inflammatory agents. Several studies led by Nakatani, published in Biochemical Pharmacology in 2002 and Molecular Pharmacology in 2004, confirmed that gamma-mangostin is a potent COX-2 inhibitor. This means that it is a factor in reducing inflammation and its associated pain. The authors conclude that gamma-mangostin "is a new useful lead compound for anti-inflammatory drug development."
Several xanthones have been studied for their efficacy in treating cancer. A paper published in the Journal of Natural Products in 2003 showed that a variety of xanthones from mangosteen were all able to inhibit the growth of human leukemia cells. The same authors in a follow up study (Bioorg Med Chem. 2004 Nov 15;12(22):5799-806) concluded that alpha-mangostin would be a candidate for preventive and therapeutic application for cancer treatment. A study by Moongkarndi and others (J Ethnopharmacol 2004; 90(1):161-166) on the effect of mangosteen pericarp extract on human breast cancer cells found that it had "potential for cancer chemoprevention.
The antioxidative ability of the xanthone mangostin was shown by Williams and others (Free Radic Res 1995; 23(2):175-184) to lower "bad" cholesterol levels. This helps prevent the buildup of plaque within blood vessels and lowers the risk of heart disease.
Several research studies have verified the traditional use of mangosteen as an antibacterial agent. For example, a study by Iinuma and others, published in the Journal of Pharmacy and Pharmacology in 1996, showed that alpha-mangostin exhibited strong antibacterial activity against Staphylococcus aureus. The authors concluded that "the compounds might find wide pharmaceutical use." Another study involving alpha-mangostin showed that it was effective against Mycobacterium tuberculosis.
Gamma-mangostin has also been shown to be effective against some viruses. One study (Planta Med 1996; 62(4):381-382) showed that it was able to cause the HIV-1 virus to remain immature and incapable of infection.
It should be noted that all the above research results were obtained in laboratory studies. To be more meaningful, follow up clinical trials using human subjects need to be carried out. However, the results to date indicate that xanthones from mangosteen may have a major role to play in the treatment of a wide range of health problems.