Scientific research on the mangosteen by a number of experts indicates that it can have well over 100 positive effects. 

Here is a partial list of topics that describe the potential benefits of taking Mangosteen food supplements:  

Anti-Bacterial
Studies show that xanthones can inhibit the reproduction of certain types of bacteria, such as, salmonella typhi and the tuberculosis bacteria.

Anti-Fungal
The xanthones of the Mangosteen were tested experimentally against three common fungi and demonstrated capability of inhibiting their growth.

Anti-Inflammatory
Researchers from India used the rind from Mangosteen to investigate its effects on other types of inflammation in the body.  the results showed suppression of acute and chronic inflammation and

In another paper studying Mangosteen's effect on inflammation, it was noted that the xanthones do no interfere with the clotting mechanism of blood or produce stomach ulcers.  Both  of these are serious side effects of anti-inflammatory drugs.

Anti-Lipidemia-lowering of blood cholesterol
Scientists from Australia and Thailand have postulated that if Mangosteen inhibits oxidative (free radical) damage, then perhaps it could help with reducing the oxidation of LDL ("bad" cholesterol) in the blood.  After  a series of experiments, scientists concluded that the xanthones from Mangosteen are effective inhibitors of LDL oxidation.

Antioxidant
After studying the antioxidant properties of the Mangosteen, a new laboratory test known as Oxygen Radical Absorbance Capacity (ORAC), developed by USDA researchers at Tuft University, researchers discovered that the Mangosteen rind exhibited "potent free radical scavenging activity."

Anti-tumor/Cancer
The anti-cancer activity of Magosteen phytoceuticals specifically Garcinone E has been well-documented.  Garcinone E, a xanthone found only in Mangosteen, is a natural compound and has been known to cause no side effects, as opposed to the (5) five commonly used chemotherapeutic agents.

Anti-Viral
Because xanthones have anti-viral capabilities, scientists at the National University of Singapore investigated the effects the Mangosteen xanthones would have on the HIV virus.  In the experiment, two xanthones demonstrated the ability to interfere with HIV protease causing the virus to remain immature and incapable of infection.