Flavonol (-)-epicatechin and its derived dimer procyanidin B2, present in high amounts in cocoa products, have been shown to exert beneficial effects on the heart and cardiovascular system; however, their mechanism of action has not been fully elucidated. We studied effects of (-)-epicatechin and procyanidin B2 on the oxidative phosphorylation of isolated rat heart mitochondria. (-)-Epicatechin and procyanidin B2 had stimulating effect (up to 30% compared to control) on substrate-driven (State 2) mitochondrial respiration. Their effect was dependent on the respiratory substrates used. (-)-Epicatechin at higher concentrations (from 0.27 µg/mL) significantly decreased (up to 15%) substrate- and ADP-driven (State 3) mitochondrial respiration in case of pyruvate and malate oxidation only. Procyanidin B2 (0.7-17.9 ng/mL) inhibited State 3 respiration rate up to 19%, the most profound effect being expressed with succinate as the substrate. (-)-Epicatechin at concentrations of 0.23 µg/mL and 0.46 µg/mL prevented loss of the cytochrome c from mitochondria when substrate was succinate, supporting the evidence of membrane stabilizing properties of this flavonol. Thus, both (-)-epicatechin and procyanidin B2 directly influenced mitochondrial functions and the observed effects could help to explain cardiometabolic risk reduction ascribed to the consumption of modest amounts of cocoa products.
- MeSH
- adenosindifosfát farmakologie MeSH
- biflavonoidy chemie farmakologie MeSH
- buněčné dýchání účinky léků MeSH
- cytochromy c metabolismus MeSH
- katechin chemie farmakologie MeSH
- krysa rodu Rattus MeSH
- oxidace-redukce MeSH
- proantokyanidiny chemie farmakologie MeSH
- srdeční mitochondrie účinky léků metabolismus MeSH
- substrátová specifita účinky léků MeSH
- sukcináty metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- adenosindifosfát MeSH
- biflavonoidy MeSH
- cytochromy c MeSH
- katechin MeSH
- proantokyanidiny MeSH
- procyanidin B2 MeSH Prohlížeč
- sukcináty MeSH
Motherwort (Leonurus cardiaca) possesses antibacterial, antioxidant, anti-inflammatory, and analgesic activities, and is used as a complementary remedy to improve heart function and blood circulation. Since cardiovascular diseases are often associated with an alteration of mitochondria, the main producers of ATP in cardiac muscle cells, the aim of our work was to determine bioactive constituents present in motherwort aerial parts extract in ethanol and investigate their effects on the functions of cardiac mitochondria. Quantitative determination of polyphenols in L. cardiaca herb extract was performed by HPLC. Mitochondrial respiration rates were evaluated using a Clark-type oxygen electrode. Mitochondrial ROS generation was determined fluorimetrically with Amplex Red and horseradish peroxidase. The results showed that constituents (chlorogenic acid, orientin, quercetin, hyperoside, and rutin) of L. cardiaca herb extract uncouple (by 20-90 %) mitochondrial oxidation from phosphorylation, partially inhibit (by ~ 40 %) the mitochondrial respiratory chain in cases of pyruvate and malate as well as succinate oxidation, and effectively attenuate the generation of free radicals in mitochondria. Since partial uncoupling of mitochondria, respiratory inhibition, and decreased ROS production are proposed as possible mechanisms of cardioprotection, our results imply that L. cardiaca herb extract could be a useful remedy to protect cardiac muscles from the effects of pathogenic processes.
- MeSH
- antioxidancia chemie izolace a purifikace farmakologie MeSH
- buněčné dýchání účinky léků MeSH
- flavonoidy chemie izolace a purifikace farmakologie MeSH
- kardiomyocyty účinky léků MeSH
- krysa rodu Rattus MeSH
- léčivé rostliny MeSH
- nadzemní části rostlin chemie MeSH
- oxidativní fosforylace účinky léků MeSH
- peroxid vodíku metabolismus MeSH
- polyfenoly chemie izolace a purifikace farmakologie MeSH
- potkani Wistar MeSH
- rostlinné extrakty chemie izolace a purifikace farmakologie MeSH
- srdeční mitochondrie účinky léků MeSH
- srdečník chemie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- flavonoidy MeSH
- peroxid vodíku MeSH
- polyfenoly MeSH
- rostlinné extrakty MeSH
Aqueous hypromellose gels are not microbiologically stable - they show signs of microorganism growth during storage. To extend the shelf-life of the gels, antimicrobial preservatives are needed. Some substances of plant origin are known for their antimicrobial properties, and thus they may be used as an alternative to synthetic preservatives. Therefore, the aim of this study was to evaluate the microbiological stability of aqueous hypromellose gel and the effectiveness of natural substances - grapefruit seed extract (GSE), concentrated cranberry juice, and a combination thereof - on the antimicrobial protection of the gel. The evaluation of the antimicrobial activity of GSE and cranberry juice showed that their antimicrobial effects differed. Both cranberry juice and GSE inhibited the growth of the standard gram-positive and gram-negative bacteria, but the effect of GSE was significantly stronger. Candida albicans was sensitive only to GSE. For this reason, in order to affect all the microorganisms studied, either a combination of 0.7% GSE and 10% cranberry juice, or 5% GSE alone may be used. The combination of GSE and cranberry juice was effective only in acidic medium (pH being 2.5-5), while the antimicrobial effect of GSE was not dependent on the pH value.
- MeSH
- antiinfekční látky farmakologie MeSH
- Candida albicans účinky léků MeSH
- deriváty hypromelózy chemie MeSH
- gely MeSH
- gramnegativní bakterie účinky léků MeSH
- grampozitivní bakterie účinky léků MeSH
- grapefruit chemie MeSH
- konzervační prostředky farmaceutické farmakologie MeSH
- rostlinné extrakty farmakologie MeSH
- semena rostlinná MeSH
- Vaccinium macrocarpon chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antiinfekční látky MeSH
- deriváty hypromelózy MeSH
- gely MeSH
- konzervační prostředky farmaceutické MeSH
- rostlinné extrakty MeSH
