PhytoScience - Science 
Mood Disorders - Invivo
Gamma-mangostin, a novel type of 5-hydroxytryptamine 2A receptor antagonist.
Chairungsrilerd N, Furukawa KI, Ohta T, Nozoe S, Ohizumi Y.
Department of Pharmaceutical Molecular Biology,
Faculty of Pharmaceutical Sciences,
Tohoku University, Sendai, Japan.
Gamma-mangostin, purified from the fruit hull of the medicinal plant Garcinia mangostana caused a parallel rightwards shift of the concentration/response curve for the contraction elicited by 5-hydroxytryptamine (5-HT) in the rabbit aorta (pA2 = 8.2) without affecting the contractile responses to KCl, phenylephrine (alpha1) or histamine (H1).
The perfusion pressure response of rat coronary artery to 5-HT (5-HT2A) was reduced concentration dependently by gamma-mangostin (IC50 = 0.32 microM). 5-HT amplified, ADP-induced aggregation of rabbit platelets (5-HT2A) was inhibited by gamma-mangostin (IC50 = 0.29 microM), whereas that induced by thrombin was not affected, nor did gamma-mangostin affect 5-HT-induced contraction of the guinea-pig ileum (5-HT3)in the presence of 5-HT1, 5-HT2 and 5-HT4 receptor antagonists.
Furthermore, 5-HT-induced contraction of the rat fundus (5-HT2B) and 5-HT-induced relaxation of the rabbit aorta in the presence of ketanserin (5-HT1) and carbachol-induced contraction of the guinea-pig ileum (muscarinic M3) were not affected by gamma-mangostin (5 microM).
Gamma-mangostin inhibited [3H]spiperone binding to cultured rat aortic myocytes (IC50 = 3.5 nM). The Kd for [3H]spiperone binding was increased by gamma-mangostin (3 nM) from 11.7 to 27.4 nM without affecting Bmax.
These results suggest that gamma-mangostin is a novel competitive antagonist, free from a nitrogen atom, for the 5-HT2A receptors in vascular smooth muscles and platelets.
PMID: 9459569 [PubMed - indexed for MEDLINE]
Mood Disorders - Invivo
Pharmacological profile of mangostin and its derivatives.
Shankaranarayan D, Gopalakrishnan C, Kameswaran L.
Mangostin (M), a naturally occurring xanthone in the rinds of the fruits of Garcinia mangostana Linn. (Guttiferae) and its derivatives such as 3-0-methyl mangostin (MM), 3,6-di-O-methyl mangostin (DM), 1-isomangostin (IM), mangostin triacetate (MT), mangostin 3,6-di-O-(tetra acetyl) glucoside (MTG) and mangostin-6,6-di-O-glucoside (MOG) were screened for various pharmacological effects in experimental animals.
With the exception of DM all the test compounds produced CNS depression characterised by ptosis, sedation, decreased motor activity, potentiation of pentobarbital sleeping time and ether anaesthesia in mice and rats.
None of the compounds exhibited analgesic, antipyretic and anticonvulsant effects. With the exception of MOG, none of the test compounds produced significant effects on the cardiovascular system of frogs and dogs. MOG produced myocardial stimulation and a rise in blood pressure which was partially blocked by propranolol. M, IM and MT produced pronounced antiinflammatory activity both by intraperitoneal and oral routes in rats as tested by carrageenininduced hind paw oedema, cotton pellet implantation and granuloma pouch techniques.
Antiinflammatory activity for M, IM and MT was observed even in bilaterally adrenalectomised rats. M, IM and MT did not produce any mast cell membrane stabilising effect and the degranulation effect of polymyxin B, diazoxide and Triton X-100 on rat peritoneal mast cells in vitro was not prevented. M, IM and MT did not alter the prothrombin time of albino rats. M alone produced significant antiulcer activity in rats.
PMID: 314790 [PubMed - indexed for MEDLINE]