The dietary flavonoid quercetin activates BKCa currents in coronary arteries via production of H2O2. Role in vasodilatation

Abstract

Quercetin increased BKCa currents via production of intracellular H(2)O(2). This effect is involved, at least partly, in the coronary vasodilator effects of quercetin.

Lipoflavon® application for pharmacological correction of endothelial dysfunction in diabetic rats

“…Так в ЕК було продемонстрова не пригнічення транскрипційних факторів NF-κB та AP-1 [28], які активуються РФК. На рівні ГМК під впливом кверцетину спостерігається активація ВК Са , яка може бути опосередкована як зв'язуванням кверцетину із естрогеновими рецепторами і подальшою стимуляцією каналів [17], так і за рахунок Н 2 О 2 -залежних сигнальних шляхів, адже кверцетин може виступати і як прооксидант [9]. Спостерігається інгі-бування протеїнкіназ, таких як ПКС і кіназа легких ланцюгів міозину [29], пригнічен-ня фосфоліпази А2 та супероксиддисмутазна активність [23].…”

Cardiovascular Protection with Danshensu in Spontaneously Hypertensive Rats

“…BKCa channels have been suggested as novel potential drug targets in hypertension. 11,12) We used tetraethylammonium (TEA) as a selective BKCa channel inhibitor. 13,14) We are the first to report that Danshensu chronic administration can re-verse K ϩ and BKCa currents down-regulation in SHR mesenteric arteries.…”

On the use of food supplements

“…Several mechanisms have been implicated, such as an increase in intracellular Ca 2+ , a decreased smooth muscle calcium-sensitivity or increased nitric oxide (NO) bioavailability [9,33]. H 2 O 2 is also suggested to play a role in quercetin-induced vasorelaxation as endothelium-derived hyperpolarizing factor [43,44]. Quercetin is known to induce the formation of H 2 O 2 [11,12].…”

“…Ageing is accompanied by changes in body composition, exemplified by the reduction of total body water and lean body mass [43]. It is furthermore known to influence the pharmacokinetics (absorption, distribution, metabolism and elimination) of drugs [16].…”

“…This family of enzymes catalyzes the conjugation of BPDE to glutathione (GSH), which neutralizes the carcinogenic potential of BPDE [42]. These GSTs are divided into five major isoforms ( , µ, , , and ), of which the isoform is found to be the most abundant isoform in erythrocytes, lung and the human skin [43][44][45][46]. In our experiments, GST effectively decreased the number of BPDE-DNA adducts in the lung epithelial cells to 75 ± 10 BPDE-DNA adducts/10 7 nucleotides (P< 0.01) ( figure 1B).…”