Vliv kyseliny gallové a polyfenolických extraktů z vinných matolin na metabolismus lipidů a hladiny leptinu na modelu hypercholesterolemické diety u potkanů
| Title in English | The influence of gallic acid and polyphenolic extracts from grape byproducts on the lipid metabolism and leptin levels on the model of hypercholesterolemic diet in rats |
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| Authors | |
| Year of publication | 2007 |
| Type | Conference abstract |
| MU Faculty or unit | |
| Citation | |
| Description | We prepared two types of extracts from two different grape byproducts. Red extract was prepared from the mixture of byproducts from varieties Andre and Blauer Portugieser and white extract from byproducts from Pinot gris. Both extracts were standardized for the total polyphenolic content and administrated to rats with hypercholesterolemic diet (1.7% of cholesterol) at the doses of 0.5; 5 or 50 mg GAE (gallic acid equivalents)/kg/day. Gallic acid was administered to animals at the same doses as extracts. Catechin and epicatechin were the major polyphenols in extracts. We observed statistically significant elevation of total cholesterol plasmatic levels in all groups except animals treated with red extract at the dose of 50 mg GAE/kg/day when compared to control animals. The elevation was probably caused by increasement of LDL cholesterol fraction and was observed in all groups when compared to controls (p<0.05). Groups pretreated with red extract at the doses of 0.5 or 5 mg GAE/kg/day had also increased levels of HDL cholesterol (p<0.05). TAG levels were increased in animals with white extract (0.5 mg GAE/kg/day) (p<0.05) and gallic acid (5 mg GAE/kg/den) medication (p<0.01) against both control groups. Levels of lipoperoxidation marker malondialdehyde were significantly higher in animals with white extract (0.5 and 5 mg GAE/kg/day) (p<0.01) a gallic acid (5 and 50 mg GAE/kg/day) (p<0.05) treatment when compared to controls. Red extract at the dose of 50 mg GAE/kg/day caused decrease in the levels of leptin compared to both hypercholesterolemic and normocholesterolemic controls (p<0.05). We observed hypolipidemic effects of red extract and its influence on the levels of leptin at the highest dose in contrary to white extract and gallic acid with their hypercholipidemic and prooxidant effects. Different effects of extracts with same major compounds are probably caused by minor polyphenols with high biological activity. |