Procyanidins, contained in many products abundant in human diet, exhibit high biological activity. However, this activity has not been fully explained at cellular and molecular levels. In this study, we determine the mechanism of interaction of procyanidin B3 with model lipid membrane. This mechanism was established on the basis of changes induced by B3 in the physical properties of lipid bilayer. The changes were investigated using steady state and time-resolved fluorescence, DSC, and FTIR. We show that procyanidin B3 causes changes in the arrangement of the polar heads of lipids, order of their acyl chains and the main lipid phase transition temperature. Furthermore, its presence in the membrane leads to a reduction in membrane dipole potential. Procyanidin B3 is anchored to membrane via hydrogen bonds formed between its OH groups and the PO2- and CO groups of lipids, causing changes in both hydrophilic and hydrophobic regions of the membrane.
- MeSH
- 2-naftylamin analogy a deriváty chemie MeSH
- biflavonoidy chemie MeSH
- diferenciální skenovací kalorimetrie MeSH
- dihydropyridiny chemie MeSH
- dimyristoylfosfatidylcholin chemie MeSH
- fluorescenční spektrometrie MeSH
- hydrofobní a hydrofilní interakce MeSH
- katechin chemie MeSH
- laurany chemie MeSH
- lipidové dvojvrstvy chemie MeSH
- proantokyanidiny chemie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- teplota MeSH
- termodynamika MeSH
- vodíková vazba MeSH
- změna skupenství MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
SCOPE: The aim of this work is to identify which proapoptotic pathway is induced in human colon cancer cell lines, in contact with proanthocyanidins extracted from various berries. METHODS AND RESULTS: Proanthocyanidins (Pcys) extracted from 11 berry species are monitored for proapoptotic activities on two related human colon cancer cell lines: SW480-TRAIL-sensitive and SW620-TRAIL-resistant. Apoptosis induction is monitored by cell surface phosphatidylserine (PS) detection. Lowbush blueberry extract triggers the strongest activity. When tested on the human monocytic cell line THP-1, blueberry Pcys are less effective for PS externalisation and DNA fragmentation is absent, highlighting a specificity of apoptosis induction in gut cells. In Pcys-treated gut cell lines, caspase 8 (apoptosis extrinsic pathway) but not caspase 9 (apoptosis intrinsic pathway) is activated after 3 hours through P38 phosphorylation (90 min), emphasizing the potency of lowbush blueberry Pcys to eradicate gut TRAIL-resistant cancer cells. CONCLUSION: We highlight here that berries Pcys, especially lowbush blueberry Pcys, are of putative interest for nutritional chemoprevention of colorectal cancer in view of their apoptosis induction in a human colorectal cancer cell lines.
- MeSH
- antigeny CD95 metabolismus MeSH
- apoptóza účinky léků MeSH
- brusnice s jedlými plody chemie metabolismus MeSH
- buněčné linie MeSH
- chemorezistence MeSH
- DNA metabolismus MeSH
- fosfatidylseriny metabolismus MeSH
- fosforylace účinky léků MeSH
- fragmentace DNA účinky léků MeSH
- kaspasa 3 metabolismus MeSH
- kaspasa 8 metabolismus MeSH
- kaspasa 9 metabolismus MeSH
- lidé MeSH
- mitogenem aktivované proteinkinasy p38 metabolismus MeSH
- nádory tračníku metabolismus patologie MeSH
- ovoce chemie metabolismus MeSH
- proantokyanidiny chemie izolace a purifikace toxicita MeSH
- protein TRAIL toxicita MeSH
- rostlinné extrakty chemie MeSH
- TRAIL receptory metabolismus MeSH
- Vaccinium vitis-idaea chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
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
The effects of condensed tannins (CTs) extracted from pine bark on egg hatching, larval development and the viability of infective L3 larvae of Trichostrongylus colubriformis (Giles, 1892) and Teladorsagia circumcincta (Stadelmann, 1894) (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. Significant inhibitory effects of CTs were obtained on the viability of the infective larvae, egg hatching and larval development of both nematodes. In all bioassays, the larval stages of Te. circumcincta were significantly (P < 0.05) more susceptible to the inhibitory effects of CT than those of Tr. colubriformis. At 1 000 microg/ml, CTs from pine bark inhibited 48% and 69% of the infective larvae of Tr. colubriformis and Te. circumcincta, respectively, from passing through the sieve relative to the control incubations (no CT added; P < 0.0001). At the same concentration, CTs were able to inhibit 36% and 47% of the eggs of the two parasites, respectively, from hatching relative to the control incubations without CTs. Moreover, at 150 microg/ml, the CTs were able to inhibit 88% and 95% (P < 0.0001 relative to control incubation) of L1 larvae of the two nematodes, respectively, from attaining the full development to L3 larvae in comparison with the control incubations without CTs. At 200 microg/ml, CTs were able to inhibit completely the larval development in both nematodes. Addition of 2 microg polyethylene glycol (PEG; tannin inhibitor) per microg CT eliminated up to 87% of the CT activity (P < 0.0001) compared to incubations without PEG. In conclusion, this study shows that CTs are able to disrupt the life cycle of nematodes and their effects varied according to the parasite species and stage.
- MeSH
- borovice chemie MeSH
- druhová specificita MeSH
- fylogeneze MeSH
- hlístice účinky léků MeSH
- kůra rostlin chemie MeSH
- larva účinky léků růst a vývoj fyziologie MeSH
- ovum účinky léků MeSH
- pohybová aktivita účinky léků MeSH
- proantokyanidiny chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Hops represent an important natural source of bioactive polyphenols, particularly proanthocyanidins, which can contribute to prevention of several civilization diseases, owing to their antioxidant and radical scavenging activity. We have developed a high-throughput ultra-high-performance liquid chromatography time-of-flight mass spectrometry profiling method, which can be used for monitoring of bioactive proanthocyanidins in hops. The method was applied for analysis of hops of four Czech varieties (Saaz, Sladek, Preminat and Agnus) from the 2011 crop (9 localities, 11 samples) and the 2012 crop (24 localities, 40 samples). Hop samples were extracted by acetone and the analytes were separated on the Acquity UPLC BEH Shield RP18 column. Partial validation of the method revealed a satisfactory intra-day repeatability of the method for retention times (relative standard deviation within 1.39%) as well as areas under the peaks (within 9.89%). Experimental data were evaluated using principal component analysis and cluster analysis. Significant amounts of di-, tri- and tetramer proanthocyanidins consisting of (epi)catechin and (epi)gallocatechin were found in the hop samples. The dependence of the proantocyanidin composition on both the variety and the growing locality was observed. Specifically, the traditional Saaz variety contained more frequently oligomers formed by (epi)catechin units only, whereas the varieties Premiant and Agnus produced oligomers consisting of (epi)catechin as well as (epi)gallocatechin units. The relative abundance of proanthocyanidins in studied hop varieties from the two crops, 2011 and 2012, did correspond to each other. In the further perspective, the method may also be used for prediction of qualitative marks or authenticity verification of hops.
- MeSH
- aceton chemie MeSH
- analýza hlavních komponent MeSH
- Humulus chemie MeSH
- katechin analogy a deriváty izolace a purifikace MeSH
- proantokyanidiny analýza chemie MeSH
- reprodukovatelnost výsledků MeSH
- rozpouštědla chemie MeSH
- rychlé screeningové testy MeSH
- shluková analýza MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
The effects of condensed tannins (CTs) extracted from five species of plants on egg hatching and larval development of Teladorsagia circumcincta (Stadelmann, 1894) (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. The extracts of CTs were obtained from Lotus pedunculatus (LP), Lotus corniculatus (LC), Dorycnium pentaphyllum (DP), Dorycnium rectum (DR) and Rumex obtusifolius (RO). The results of egg hatching assay showed that about 53%, 68%, 51%, 60% and 46% of the eggs hatched when in vitro incubations contained 900 microg/ml of CTs from LP, LC, DP, DR and RO, respectively (P < 0.001 relative to control incubation), while in control incubations (no CT added) 87% of the eggs hatched. In the larval development assay, development was allowed to proceed for 7 days, by which time 89% of the hatched larvae in control wells (no CTs) had reached the infective third stage (L3). In incubations containing 200 microg CT from LP, LC, DP, DR and RO/ml, about 8%, 15%, 14%, 8% and 4% of the eggs attained full development to L3 larvae, respectively (P < 0.001 relative to control incubation). Only 1% of the eggs were able to develop to L3 larvae in incubations containing 400 microg CT extracted from LC/ml, whilst in the incubations containing the same concentration of other CTs the eggs were not able to develop to L3 larvae. It seems that CTs are not only slowing down the larval development but also kill the undeveloped larvae. At 400 microg/ml, for example, CT from LP, LC, DP, DR and RO killed 67%, 48%, 68%, 93% and 91% of first-stage (L1) and second-stage (L2) larvae, respectively. This study shows that CTs are able to disrupt the life cycle of nematodes.
