Publication details
Vliv polyfenolických extraktů z vinných matolin na aktivitu CYP 1A2 u potkanů s hypercholesterolemickou dietou
| Title in English | The influence of polyphenolic extracts from grape byproducts on the metabolic activity of CYP 1A2 in rats with hypercholesterolemic diet |
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| Authors | |
| Year of publication | 2007 |
| Type | Article in Proceedings |
| Conference | Sborník abstrakt, 12. Mezioborová Česko-slovenská toxikologická konference |
| MU Faculty or unit | |
| Citation | |
| Field | Pharmacology and pharmaceutical chemistry |
| Keywords | CYP 1A2; polyphenols; grape byproducts |
| Description | Diet is one of the most important factors influencing the human health. Not only the amount, but especially the composition of food is an essential parameter of its positive or negative effect. From this point of view the modulation of diet composition is suitable for prevention of many serious diseases of cardiovascular system, obesity or diabetes mellitus. These positive or protective effects are mainly caused by non-nutrient components like polyphenols or isothiocyanates. It is believed that they can protect various organs from free radicals damage. Also many other benefit effects are proved by recent studies1. Polyphenolic substances are widely distributed in plants namely in fruits and vegetables. Thus their daily intake can be easily modified. The problem is that people are often not willing to change their eating habits and prefer using these protective substances in the form of pills or enriched food products. Great source of polyphenols are plant waste materials such as grape byproducts which are formed after grape pressing in the process of wine production and are composed of grape peels and seeds. Moreover extracts rich in polyphenols can be prepared from this material easily. Biological effects of polyphenols are mediated by numerous mechanisms. They can interact with specific receptors2, structures3, signal pathways4 or can change the activities of enzymatic systems. One of the most important metabolic systems is cytochrome P450 (CYP450). It is composed of many isoenzymes, which are localized on different sites of organism, but predominantly in liver. The majority of xenobiotics including drugs as well as many of endogenous metabolites are substrates for CYP450 and many of them can also influence its metabolic activity. Thanks to this is knowledge of inductive or inhibitory activity of administrated substances necessary for evaluation of their possible toxicity and interactions with substrates for CYP450. It is known, that flavonoids are inhibitors of CYP4505 and decrease the activation of some procarcinogens to carcinogens by this enzymatic system. On the other hand some authors showed data indicating inductive activity of polyphenols on CYP4506. The aim of our work was to prepare extracts from grape byproducts rich in polyphenols and to investigate their influence on the activity of hepatic CYP450 1A2 (CYP1A2) isoenzyme in hypercholesterolaemic rats. The influence of administered extracts on the activity of CYP1A2 was in general inductive. The levels of PAR were higher during the whole perfusion (WG; p<0.05) or in the 30th min of perfusion (RG; p<0.05) in comparison to CG animals. We have also observed increased levels of PHEN in the 30th minute of perfusion in RG (p<0.01) and WG group (p<0.05) compared to CG. Hypercholesterolaemic diet have no influence on the activity of CYP1A2 which was confirmed by similar concentration of PAR and PHEN in CG and HG animals |
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