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Antioxidant activity of phenolic fractions from Vaccinium vitis-idaea L. leaves
Date Issued |
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2021-04-23 |
Poster presentations. Pharmacy
Buvo eISSN 1648-9233.
Background. Lingonberry (Vaccinium vitis-idaea L.) leaves are regarded to be a good source of phenolic compounds, which are promising multi-targeting agents in the treatment of various diseases because of versatile antioxidant activity. However, the contribution of individual phenolics or particular groups to the antioxidant activity of lingonberry leaves has not been extensively studied directly. This complicates the identification of lingonberry’s antioxidant activity markers. Aim. The present study aimed at isolation and of phenolic fractions from lingonberry leaves and evaluation of their antioxidant activity. Methods. Powder of crude dry extracts of lingonberry leaves (marked L1) was applied to a glass column (3×60cm) packed with already equilibrated Sephadex LH-20 and eluted successively with one column volume of water (to obtain L2), four volumes of 50% ethanol (to obtain L3) and two volumes of 70% acetone (to obtain L4). For each fraction phenolic composition was determined by validated HPLC-PDA method and the radical scavenging, reducing, and chelating activities were investigated, using ABTS, FRAP, and FIC assays, respectively. Results of antioxidant activity assays were expressed as micromolar of standard antioxidant – Trolox or strong chelating agent – EDTA equivalents per gram of dry weight of fractions (μM TE/g DW and μM EDTA/g DW, respectively). Results. The radical scavenging activity assessed by ABTS assay ranged between 4204.1 and 7832.7 μM TE/g DW, with the lowest and highest (p<0.05) values determined in the fraction enriched with arbutin (L2) and fraction with predominant compounds of polymeric and mainly A-type dimeric proanthocyanidins (L4), respectively. In FRAP assay, L3 fraction with prevailing compounds of catechins and flavonols, surpassed all other fractions by the greatest (p<0.05) reducing activity of 5316.7 μM TE/g DW, followed by L4 fraction. FIC assay showed a simil [...].