Determination of antioxidant activity of Prunus padus L. flowers

Background. Prunus padus L., also known as bird cherry, flowers are rich in minerals, vitamins and phenolic compounds [1]. It has been confirmed that consumption of plants which are rich in polyphenols can have a health-promoting effect [2]. And studies confirm favourable effects of P. padus for prevention of cardiovascular diseases, as well as antioxidant, anti-inflammatory, antimicrobial, antidiabetic effects [3]. Aim. The objective of this study was to determine antioxidant activity in flowers of Prunus padus L. from various regions of Lithuania. Methods. P. padus flowers were collected during mass flowering in late spring of 2024. Flowers were air dried at room temperature and grinded to fine powder. Extracts were prepared with 60% methanol as extractant in an ultrasonic bath. The antioxidative potential of flowers was determined using spectrophotometric ABTS (2,2’azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (ferric reducing antioxidant power) methods. Results. Average antiradical activity in samples of P. padus flowers from various locations in Lithuania was 145.27 ± 7.05 µmol/g based on ABTS method. Antioxidant activity in extracts varies from 68.80 ± 38.98 µmol/g (Babtai, Kaunas district), 81.16 ± 16.13 µmol/g (Kaunas) to 212.82 ± 17.06 µmol/g (Kyburiai, Utena district), 221.32 ± 17.80 µmol/g (Liauðiai, Ukmergë district). Based on FRAP method, average reducing activity in samples of P. padus flowers was 34.39 ± 1.32 µmol/g. Antioxidant activity in extracts varies from 17.67 ± 0.85 µmol/g (Kaunas), 23.56 ± 3,61 µmol/g (Babtai, Kaunas district) to 50.62 ± 4.15 µmol/g (Kemetiðkiai, Molëtai district), 52.58 ± 18.68 µmol/g (Padumblë, Molëtai district). Correlation between antiradical activity results from two different methods is statistically significant. Conclusion. Results confirm that Prunus padus L. flowers from various locations in Lithuania possess antioxidant activity. Environmental conditions, age of plant and other conditions have a significant influence on the antioxidant effect of P. padus flower extracts. Therefore, in order to predict biological effects, analysis of the produced extracts of raw plant materials should be performed.