In vitro: |
Planta Med. 2002 Jul;68(7):642-4. | Antiplasmodial activity of labdanes from Aframomum latifolium and Aframomum sceptrum.[Pubmed: 12143001] | METHODS AND RESULTS: Bioguided fractionation of extracts of Aframomum latifolium and A. sceptrum (Zingiberaceae) resulted in isolation of (+)-( S)-nerolidol and seven labdanes, coronarin B, galanal A and B, Galanolactone, ( E)-8beta,17-epoxylabd-12-ene-15,16-dial, (+)-( E)-labda-8(17), 12-diene-15,16-dial and its diethyl acetal, the latter being presumably an isolation artefact.
CONCLUSIONS:
The labdanes show a modest in vitro activity against a chloroquine-sensitive Plasmodium falciparum strain. | Chem Pharm Bull (Tokyo). 1991 Feb;39(2):397-9. | Anti-5-hydroxytryptamine3 effect of galanolactone, diterpenoid isolated from ginger.[Pubmed: 2054863] | It has been reported that an acetone extract of ginger and its fractions have anti-5-HT (5-hydroxytryptamine; serotonin) effects. METHODS AND RESULTS: In the present study, guinea pig ileum, rat stomach fundus and rabbit aortic strips are used in order to determine the constituents of fraction 2 which are responsible for anti-5-HT effect and to examine their pharmacological properties. The analysis of fraction 2-3 indicated that Galanolactone, a diterpenoid, is one of the active constituents. In guinea pig ileum, Galanolactone inhibited contractile responses to 5-HT with a pIC50 value 4.93. pIC50 value of Galanolactone against the response to 2-methyl-5-HT, a selective 5-HT3 agonist, in the presence of methysergide at 1 x 10(-5) M was 5.10. pIC50 values of ICS 205-930, a selective 5-HT3 antagonist, were 5.30 and 7.49, respectively. The concentration-response curve of 5-HT was shown as a biphasic curve and Galanolactone caused a selective shift to the right of the second phase. In the same preparations, the pIC50 value of Galanolactone and ICS 205-930 against the response to carbamylcholine (CCh) was 4.45 and 4.46. The inhibitory effect of Galanolactone on the 5-HT response in the stomach fundus and aortic strips was less than that in the ileum. In addition, in the thoracic aorta precontracted with 50 mM K+, the relaxing effect of Galanolactone was about 1/10 of that of papaverine. CONCLUSIONS:
These results suggest that the anti-5-HT effect of Galanolactone, a diterpenoid isolated from ginger, is related to antagonism of 5-HT3 receptors. |
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