RESUMO
In this study, the direct influence of bilberry (Vaccinium myrtillus) fruit extracts (aqueous and ethanolic) rich in anthocyanins on the oxidative phosphorylation of isolated rat heart mitochondria was investigated in vitro. Higher concentrations of bilberry extracts concentration-dependently inhibited mitochondrial state 3 respiration (by 23%-61%) with pyruvate plus malate, mildly (by 1.2- to 1.3-fold) uncoupled the oxidative phosphorylation, and increased (by 30%-87%) the state 4 respiration rate in the presence of exogenous cytochrome c. Succinate oxidation was less affected. Pure anthocyanins, the main components of used extracts, malvidin-3-glucoside, malvidin-3-galactoside, and cyanidin-3-galactoside, had no effect on oxidation of pyruvate plus malate. A statistically significant decrease in H2 O2 production by mitochondria was found in the presence of bilberry fruit extracts. Our findings show that bilberry fruit anthocyanin-rich extracts possess direct effects on rat heart mitochondrial function in vitro. These findings give the first insights into the mechanism(s) of their action on cellular energy metabolism.
Assuntos
Antocianinas/farmacologia , Antioxidantes/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Vaccinium myrtillus/química , Animais , Frutas/química , Galactosídeos/farmacologia , Peróxido de Hidrogênio/metabolismo , Malatos/metabolismo , Masculino , Mitocôndrias Cardíacas/metabolismo , Fosforilação Oxidativa , Extratos Vegetais , Ácido Pirúvico/metabolismo , Ratos , Ratos WistarRESUMO
Flavonoids are an important group of natural compounds, which can prevent coronary heart disease and have antioxidant properties. Hawthorn is a well known and widely used medicinal plant due to its cardiotonic activity. Previous studies refer mostly to the HPLC analysis of the flavonoids: vitexin, quercetin, hyperoside, oligomeric procyanidins, which appear to be primarily responsible for the cardiac action of the plant. Aqueous ethanolic extracts of single-styled hawthorn (Crataegus monogyna Jacq., f.: Rosaceae Juss.) leaves and sprouts were analyzed by means of capillary zone electrophoresis (CZE). Influence of vegetation period on the extract qualitative composition and flavonoids quantities was evaluated. Sample preparation by extraction using different concentration of aqueous ethanol (40-96%, v/v) and the influence of extractant composition on the recovery of flavonoids are discussed in detail. The results obtained using CZE are compared to the results of spectrophotometric and HPLC analysis of the extracts. The effect of storage conditions of extracts (solar irradiation, temperature and duration) on degradation of flavonoids was investigated.