title: Effect of natural phenol derivatives on skeletal type sarcoplasmic reticulum Ca2+ -ATPase and ryanodine receptor.
abstract: The effect of natural phenol derivatives was studied on skeletal type sarcoplasmic reticulum Ca(2+)-ATPase and ryanodine receptor. The majority of the tested derivatives exerted inhibitory effect on the Ca(2+)-ATPase with an ascending sequence in regard to their effectiveness (IC(50)): cineole (3.33 mM) < ortho-vanillin (IC(50 )=1.13 mM) < 4-methyl-2-nitrophenol (1104 microM) < vanillin (525 microM) < thymol (224 microM) < carvacrol (162 microM). In two cases biphasic characteristic was observed: trans-anethole and meta-anisaldehyde first caused activation followed by inhibition (with IC(50)-s of 141 and 1903 microM respectively) as their concentration was increased. In some cases (cineole, ortho-vanillin, meta-anisaldehyde) total inhibition of Ca(2+)-ATPase could not be reached as the result of the limited solubility of these drugs. Para-anisaldehyde and 6-amino-meta-cresol did not show any effect up to 3 mM. In Ca(2+) release experiments drugs were applied on heavy sarcoplasmic reticulum vesicles isolated from skeletal muscle and actively loaded with calcium. Only thymol and carvacrol were able to evoke Ca(2+) release with EC(50) values of 158 +/- 16 and 211 +/- 55 microM respectively. Furthermore the effect of thymol and carvacrol was tested on the isolated ryanodine receptor incorporated into artificial lipid bilayer. Both drugs activated the RyR when applied in concentrations identical to their EC(50) values. These observations show that small differences in the structure of phenol derivatives sometimes have little impact on their effect on the sarcoplasmic reticulum Ca(2+)-ATPase or ryanodine receptor (thymol and carvacrol) whereas in certain cases they can completely abolish a particular effect (para- and meta-anisaldehyde).
authors.affiliation: Department of Physiology, Medical and Health Science Centre, University of Debrecen, PO Box 22, Debrecen 4012, Hungary.
authors.forename: Sándor
authors.initials: S
authors.lastname: Sárközi
authors.forename: János
authors.initials: J
authors.lastname: Almássy
authors.forename: Balázs
authors.initials: B
authors.lastname: Lukács
authors.forename: Nóra
authors.initials: N
authors.lastname: Dobrosi
authors.forename: Georgina
authors.initials: G
authors.lastname: Nagy
authors.forename: István
authors.initials: I
authors.lastname: Jóna
mesh_terms: D000818:Animals; D001547:Benzaldehydes / Q000737:chemistry / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003511:Cyclohexanols / Q000737:chemistry / Q000494:pharmacology; D000081007:Cymenes; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D000077591:Eucalyptol; D008567:Membranes, Artificial; D015394:Molecular Structure; D039821:Monoterpenes / Q000737:chemistry / Q000494:pharmacology; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D019837:Ryanodine Receptor Calcium Release Channel / Q000187:drug effects* / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000187:drug effects* / Q000378:metabolism; D034421:Sus scrofa; D013943:Thymol / Q000737:chemistry / Q000494:pharmacology
chemical_list: D001547:Benzaldehydes; D003511:Cyclohexanols; D000081007:Cymenes; D004791:Enzyme Inhibitors; D008567:Membranes, Artificial; D039821:Monoterpenes; D010636:Phenols; D019837:Ryanodine Receptor Calcium Release Channel; D013943:Thymol; C073316:carvacrol; C100058:vanillin; D000252:Calcium-Transporting ATPases; D000077591:Eucalyptol; D002118:Calcium