PhytoScience - Science 
Anti-histamine - Invtro
Inhibitions of histamine release and prostaglandin E2 synthesis by mangosteen, a Thai medicinal plant.
Nakatani K, Atsumi M, Arakawa T, Oosawa K, Shimura S, Nakahata N, Ohizumi Y.
Department of Pharmaceutical Molecular Biology,
Graduate School of Pharmaceutical Sciences,
Tohoku University, Sendai, Japan.
The fruit hull of mangosteen, Garcinia mangostana L. has been used as a Thai indigenous medicine for many years. However, its mechanism of action as a medicine has not been elucidated.
The present study was undertaken to examine the effects of mangosteen extracts (100% ethanol, 70% ethanol, 40% ethanol and water) on histamine release and prostaglandin E2 synthesis.
We found that the 40% ethanol extract of mangosteen inhibited IgE-mediated histamine release from RBL-2H3 cells with greater potency than the water extract of Rubus suavissimus that has been used as an anti-allergy crude drug in Japan.
All extracts of mangosteen potently inhibited A23187-induced prostaglandin E2 synthesis in C6 rat glioma cells, while the water extract of Rubus suavissimus had no effect. The 40% ethanol extract of mangosteen inhibited the prostaglandin E2 synthesis in a concentration-dependent manner with relatively lower concentrations than the histamine release. In addition, passive cutaneous anaphylaxis (PCA) reactions in rats were significantly inhibited by this ethanol extract as well as by the water extract of Rubus suavissimus.
These results suggest that the 40% ethanol extract of mangosteen has potent inhibitory activities of both histamine release and prostaglandin E2 synthesis.
PMID: 12230104 [PubMed - indexed for MEDLINE]
Anti-histamine - Invtro
Novel types of receptor antagonists from the medicinal plant Garcinia mangostana.
[Article in Japanese]
Furukawa K, Chairungsrilerd N, Ohta T, Nozoe S, Ohizumi Y.
Department of Pharmaceutical Molecular Biology, Faculty of Pharmaceutical Sciences,
Tohoku University, Sendai, Japan.
A crude methanolic extract of the fruit hull of Garcinia mangostana L. inhibited the contraction of the isolated rabbit aorta induced by histamine and serotonin.
The extract has been fractionated by silica gel chromatography, monitoring the pharmacological activity to give active compounds. On the basis of physicochemical data, the active substances were identified as alpha-mangostin and gamma-mangostin.
To define the pharmacological properties of alpha-mangostin, the effect of alpha-mangostin on both histamine H1 and H2 receptors were examined by monitoring the mechanical responses of smooth muscles and measuring the radioligand binding to cultured vascular smooth muscle cells.
The results suggest that alpha-mangostin acts as a selective and competitive histamine H1 receptor antagonist.
The pharmacological actions of gamma-mangostin on 5-HT receptors were also investigated by using contractile response of vascular smooth muscle, platelet aggregation and radioligand binding studies.
The results provide the evidence that gamma-mangostin is a selective and competitive 5-HT2A receptor antagonist. It is of great interest that the structures of alpha-mangostin and gamma-mangostin free from nitrogen atom are not resemble to the common structures of histamine and serotonin receptor antagonists. alpha-Mangostin and gamma-mangostin may become novel types of lead compounds for histamine and serotonin receptor antagonists.
PMID: 9503424 [PubMed - indexed for MEDLINE]
Anti-histamine - Invivo
Histaminergic and serotonergic receptor blocking substances from the medicinal plant Garcinia mangostana.
Chairungsrilerd N, Furukawa K, Ohta T, Nozoe S, Ohizumi Y.
A crude methanolic extract of the fruit hull of Mangosteen, Garcinia mangostana L. inhibited the contractions of isolated thoracic rabbit aorta induced by histamine and serotonin.
The extract of the fruit hull has been fractionated by silica gel chromatography, monitoring the pharmacological activity to give alpha- and gamma-mangostin.
On the basis of pharmacological data, it is suggested that alpha-mangostin and gamma-mangostin are a histaminergic and a serotonergic receptor blocking agent, respectively.
PMID: 8923814 [PubMed - indexed for MEDLINE]