What is mangosteen?
Garcinia mangostana is a tropical fruit that grows primarily in the hot, humid climates of southeast Asian Basin in countries like Thailand, Malaysia, Singapore, Vietnam, and Indonesia. 
Mangosteen, unrelated to Mango, is a dark purple fruit about 2 to 3 inches in diameter, with a thick rind (called pericarp) surrounding a soft ,opaque white fruit in the middle. The center, which resembles a head of garlic, tastes like anything but, being slightly sweet and tart, described as “exquisitely luscious” to “delicious”. It is often referred to as “The Queen of Fruits” because of its flavor and appearance.
Why do people use mangosteen?
People eat Mangosteen as they would any other tropical fruit.
In southeast Asia, the rind—or pericarp—has been used for medicinal purposes for many years. Folklore states the rind was used to make a tea to treat conditions from diarrhea to bladder infections, even, gonorrhea! An ointment was made from the pericarp and was applied to the skin for rashes and other lesions. It appears they may not have been that far off. These effects may be due to chemical substances called tannins, present in the rind, which are known to be effective for these conditions.
Now we know the pericarp or rind, also contains strong antioxidant compounds called Xanthones, the most studied of which are alpha-mangostin, beta-mangostin, garcinone B, and garcinone E.
In laboratory studies, Mangosteen has been found to have anti-inflammatory, antimicrobial, antifungal, and antiseptic properties (need list of references). Xanthones appear to have anti-cancer effects well (more references).
In southeast Asia, the rind—or pericarp—has been used for medicinal purposes for many years. Folklore states the rind was used to make a tea to treat conditions from diarrhea to bladder infections, even, gonorrhea! An ointment was made from the pericarp and was applied to the skin for rashes and other lesions. It appears they may not have been that far off. These effects may be due to chemical substances called tannins, present in the rind, which are known to be effective for these conditions.
Now we know the pericarp or rind, also contains strong antioxidant compounds called Xanthones, the most studied of which are alpha-mangostin, beta-mangostin, garcinone B, and garcinone E.
In laboratory studies, Mangosteen has been found to have anti-inflammatory, antimicrobial, antifungal, and antiseptic properties (need list of references). Xanthones appear to have anti-cancer effects well (more references).
references:
Duke, James, ed. Dr. Duke's Phytochemical and Ethnobotanical Databases. United States Department of Agriculture, Agricultural Research Service, Accessed April 27, 2004 from: http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl?1228
Hedrick, U.P. (ed.) 1972. Sturtevant's Edible Plants of the World. NY, NY: Dover Publications, Inc., 1972. Downloaded from: www.swsbm.com/
Morton, Julia F. Mangosteen. In: Fruits of Warm Climates. Self-published. Miami, FL, 1987, pp. 301-304. ISBN: 0-9610184-1-0
http://chetday.com/mangosteen.htm
http://chetday.com/mangosteen.htm
http://altmedicine.about.com/od/completeazindex/a/mangosteen1.htm