monensin and hyperforin

monensin has been researched along with hyperforin* in 1 studies

Other Studies

1 other study(ies) available for monensin and hyperforin

ArticleYear
Inhibition of synaptosomal uptake of 3H-L-glutamate and 3H-GABA by hyperforin, a major constituent of St. John's Wort: the role of amiloride sensitive sodium conductive pathways.
    Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2000, Volume: 23, Issue:2

    Extracts of St. John's Wort are widely used for the treatment of depressive disorders. The active principles have not yet been finally elucidated. We have recently shown that hyperforin, a major active constituent of St. John's Wort, not only inhibits the neuronal uptake of serotonin, norepinephrine and dopamine, but also that of L-glutamate and GABA. No other antidepressant compound exhibits a similar broad uptake inhibiting profile. To investigate this unique kind of property, kinetic analyses were performed regarding the uptake of 3H-L-glutamate and 3H-GABA into synaptosomal preparations of mouse brain. Michaelis-Menten kinetics revealed a reduction of Vmax (8.27 to 1.80 pmol/mg/min for 3H-L-glutamate, 2.76 to 0.77 pmol/mg/min for 3H-GABA) while Km was nearly unchanged in both cases, suggesting non-competitive inhibition. The unselective uptake inhibition by hyperforin could be mimicked by the Na+-ionophore monensin and by the Na+-K+-ATPase inhibitor ouabain. However, both mechanisms can be discarded for hyperforin. Several amiloride derivatives known to affect sodium conductance significantly enhance 3H-GABA and 3H-L-glutamate uptake and inhibit the uptake inhibition by hyperforin, while monensin or ouabain inhibition were not influenced. Selective concentrations of benzamil for amiloride sensitive Na+-channels and selective concentrations of 5'-ethylisopropylamiloride (EIPA) for the Na+-H+-exchangers both had an attenuating effect on the hyperforin inhibition of L-glutamate uptake, suggesting a possible role of amiloride sensitive Na+-channels and Na+-H+-exchangers in the mechanism of action of hyperforin.

    Topics: Animals; Biological Transport; Bridged Bicyclo Compounds; Dose-Response Relationship, Drug; Excitatory Amino Acid Antagonists; Female; GABA Antagonists; gamma-Aminobutyric Acid; Glutamic Acid; Hypericum; Ionophores; Mice; Mice, Inbred Strains; Monensin; Neurotransmitter Uptake Inhibitors; Ouabain; Phloroglucinol; Plants, Medicinal; Sodium Channels; Synaptosomes; Terpenes

2000
chemdatabank.com