Hydrogen peroxide scavenging potential of lingonberry phenolics: perspectives in Covid-19 protection and prevention
| Date |
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2022-03-02 |
Session 7 - 8-Minutes oral presentations
Antioxidants are involved not only in the mechanism of chronic degenerative diseases but also in infectious illnesses, including viral respiratory diseases. Excessive production of reactive oxygen species, leading to cell damage or death, plays a major role in Covid-19 occurrence, revival, and resilience. In the field of alternative or complementary medicines, the use of herbal phytopharmaceuticals for the prevention or treatment of post-Covid long-term effects may be a promising strategy. Therefore, the present study aimed at the isolation and evaluation of reactive oxygen species, namely hydrogen peroxide, scavenging capacity of phenolic fractions from Vaccinium vitis-idaea L. (lingonberry) leaves and fruits. Powder of crude dry extracts of lingonberry leaves or fruits (marked L1 and F1, respectively) was applied to a glass column packed with already equilibrated Sephadex LH-20 and eluted successively with different polarity solvents to remove non-phenolic lingonberry constituents, as sugars (waste) and to obtain anthocyanins and phenolic acids (F2), arbutin (L2), flavonols and flavan-3-ols (L3 and F3) and proanthocyanidinsrich (L4 and F4) fractions. For each fraction phenolic composition was determined by the validated HPLC-PDA method and H2O2 scavenging activity was investigated using the spectrophotometrical assay. Results of the antioxidant activity assay were expressed as percentage inhibition. Obtained lingonberry crude extracts and phenolic fractions (31.25–625 μg/mL) were found to be active against H2O2 in a concentration-dependent manner. Average scavenging activity values decreased in the following order: L4 > F4 > reference antioxidant (ascorbic acid) > L1 > L3 > F3 > F2 > F1 > L2. At high concentrations (> 500 μg/mL) proanthocyanidins from lingonberry leaves (L4) and fruits (F4) exhibited >80% scavenging activity, which was significantly (p < 0.05) greater than that of reference antioxidant and other phenolics fractions. This work suggests lingonberry proanthocyanidins as powerful candidates for oxidative stress and post-Covid conditions targeted phytopharmaceuticals.