The fruit hull of Garcinia mangostana Linn (Guttiferae) is used as an anti-inflammatory drug in Southeast Asia. Two xanthones,
a- and c-mangostins, were isolated from the fruit hull of G. mangostana, and both significantly inhibited nitric oxide (NO) and PGE2
production from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The IC50 values for the inhibition of NO production by
a- and c-mangostins were 12.4 and 10.1 lM, respectively. After iNOS enzyme activity was stimulated by LPS for 12 h, treatment with
either a- or c-mangostin at 5 lg/ml (12.2 and 12.6 lM, respectively) for 24 h did not significantly inhibit NO production. The data show
that the inhibitory activities of a- and c-mangostins are not due to direct inhibition of iNOS enzyme activity. On the other hand, expression
of iNOS was inhibited by a- and c-mangostins in LPS-stimulated RAW 264.7 cells, but not by COX-2. However, the level of PGE2
production was reduced by the two xanthones. In an in vivo study, a-mangostin significantly inhibited mice carrageenan-induced paw
edema. In conclusion, a- and c-mangostins from G. mangostana are bioactive substances with anti-inflammatory effects.
2007 Elsevier Ltd. All rights reserved.