No abstract

No abstract

Lingonberry leaves and fruits are associated with a range of potential bioactivities related to their phenolic content and composition, but the identification of major biological activity markers remains limited. The present study aimed at the isolation of lingonberry phenolic fractions and biological activity evaluation of them. Crude dry extracts of lingonberry leaves and fruits were fractionated by chromatography using Sephadex LH-20 and analyzed by validated HPLC-PDA method. For each fraction, the anticancer activity against human clear cell renal cell carcinoma (CaKi-1), human colon adenocarcinoma (HT-29), and human malignant melanoma (IGR39) cell lines was determined using MTT assay, and the radical scavenging, reducing, and chelating activities were investigated using ABTS, FRAP, and FIC assays, respectively. Further, 28 phenolics were identified and quantified in the crude extract of lingonberry leaves and 37 in the extract of fruits. These compounds, during fractionation steps, were selectively eluted into active fractions, enriched with different groups of phenolics—monophenols, anthocyanins, phenolic acids, catechins, flavonols, or proanthocyanidins. Fractions of lingonberry leaves and fruits, obtained by the last fractionation step, proved to be the most active against tested cancer cell lines and possessed the greatest antioxidant activity. In this perspective, the predominant compounds of these fractions—polymeric and mainly A-type dimeric proanthocyanidins—also quercetin can be considered to be anticancer and antioxidant activity markers of lingonberries.

Rowanberries have been traditionally used in various processed foods. Scientific research demonstrates the pharmacological effects of Sorbus L. fruits are determined by their unique composition of biologically active compounds. The aim of this study was to determine the composition of flavonoids, phenolic acids, anthocyanins, carotenoids, organic acids and sugars as well as the total antioxidant activity in fruit powders of 20 Sorbus cultivars. Chemical profiles of rowanberry fruit powders vary significantly. Cultivars ‘Burka’, ‘Likernaja’, ‘Dodong’, and ‘Fructo Lutea’ distinguish themselves with exclusive phytochemical composition and high antioxidant activity. Fruit powders from ‘Burka’, ‘Likernaja’ contain the highest contents of anthocyanins while fruit powder samples from ‘Fructo Lutea’ and ‘Dodong’ contain the highest levels of phenolic acids, ascorbic acid and the lowest levels of fructose. Fruit powder samples from ‘Dodong’ also contain the highest levels of β-carotene and sorbitol and the lowest levels of malic acid. Cultivars ‘Burka’, ‘Likernaja’, ‘Dodong’, and ‘Fructo Lutea’ could be selected as eligible raw materials for the preparation of rowanberry fruit powders.

Lingonberry leaves are the subject of numerous studies because of antioxidant properties, positive influence on the health and potential use in the prevention and treatment of chronic diseases. In this work, the radical scavenging, reducing, chelating activities, and phenolic composition of ten lingonberry leaves cultivars, one subspecies, and one variety were investigated. Furthermore, the antioxidant activity of individual phenolic compounds, that can be found in lingonberry leaves, were analyzed, and structure-activity relationship was determined. Wide diversity for phenolic profile and antioxidant properties of lingonberry leaves has been observed in the present material. Cultivars ‘Kostromskaja rozovaja’, ‘Rubin’, and Vaccinium vitis-idaea var. leucocarpum surpassed all others tested cultivars and lower taxa by contents of phenolic compounds and antioxidant activity. Leaves of lingonberry cultivars and lower taxa are rich in arbutin, flavonol glycosides, proanthocyanidins, and the latter were considered to be the major contributor to antioxidant properties of lingonberry leaves.