Pharmaceutical interest

Muscarinic properties of liriodenine: One might set the hypothesis that Fissitigma species assuage stomachaches on account of isoquinoline

OCH3 O

5 - Methoxy - 7- hydroxyflavanone

OCH3 O

5 - Methoxy - 7- hydroxyflavanone

Uses: Malaysians have been known to drink decoctions of Fissistigma manubriatum (Hook. f. & Thoms.) Merr. (Melodorum manubriatum Hook. f. & Thoms.), Fissistigma lanuginosum or Fissistigma kingii to assuage stomachaches, and the leaves of Fissistigma fulgens are applied externally to soothe inflammation.

Fig. 9. Fissistigma latifolium (Dunal) Merr. var. ovoideum.

alkaloids, such as liriodenine, which are known to block muscarinic receptors and therefore impede both the secretion of gastric juices and the contraction of the gastric smooth muscles. Liriodenine (an oxoapor-phine), characterized from Fissistigma glaucescens, inhibits the contraction of isolated portions of guinea-pig trachea induced by carbachol. Liriodenine is slightly more potent than methocramine but less potent than atropine, pirenzepine and 4-diphenyl-acetoxy-N-methylpiperidine. Liriodenine (300 ^M) partially inhibits the contraction induced by potassium, leukotriene C4, neurokinin A, prosta-glandine F2a, histamine and U46619. Liriodenine does not affect the tracheal contraction induced U46619 and neurokinin in the presence of nifedipine (1 ^M) or in the presence of a calcium-free medium, and it has no effect on the cAMP and cGMP content of the trachea. Liriodenine is a selective muscarinic receptor antagonist in isolated portions of ileum and cardiac preparations (Lin C etal., 1994). Liriodenine has inotropic positive property and is a potential candidate for the treatment of cardiac arrhythmia (Lin C et al., 1993). Further experiments using whole-cell voltage clamp show that liriodenine suppresses ventricular arrhythmia through blockade of Na+-channels (Chang GJ etal., 1996).

Note that the vascular and cardioprotective effects of liriodenine in ischemia-reperfusion injury involves NO-dependent pathway (Chang WL etal., 2004).

Other properties: Atherosperminine from Fissistigma glaucescens inhibits the aggregation of platelets caused by adenosine-5-diphosphate, collagen and the platelet activating factor, and relaxes portions of rat thoracic aorta (Chen K et al., 1996). Another vasodilatating alkaloid characterized from the genus Fissistigma is (-)-discretamine (see Cyathostemma argenteum; Ko FN et al., 1994). Fissistigma lanuginosum elaborates a chalcone, pedicin, which inhibits the assembly of tubulin (IC50 = 300 mm; Alias Y et al., 1995).

Fig. 9. Fissistigma latifolium (Dunal) Merr. var. ovoideum.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

Get My Free Ebook


Post a comment