Antioxidant Activity and Bioactive Compounds of Rosa Canina L. Herbal Preparations

The aim of the present research was to make a comparison between two Bulgarian commercial forms of Rosa canina L. for herbal preparations in terms of the possible benefits by oral intake. The plant samples were investigated for their antioxidant activity and the bioactive substances. The total phenolic content of the extracts was evaluated as well. Four reliable methods (DPPH, ABTS, FRAP and CUPRAC assays) for antioxidant activity assessment were applied. The highest results were recorded by the FRAP assay.The plant Rosa canina is known as wealthy source of carotenoids and organic acids, therefore fat soluble β-carotene, lycopene and lutein in addition to water soluble malic, citric, fumaric and ascorbic acids were evaluated by HPLC-methods. According the conducted assays the tested samples have similar composition. Lutein concentration in both tested extracts was calculated as 6.9 μg/g DW. Lycopene and β-carotene were determined to be 13.91 and 12.18 μg/g DW and 27.14 and 22.83 μg/g DW, respectively. HPLC determination of organic acids showed that the amount of citric acid in the extracts was 7343 and 6583 μg/g DW and fumaric acid content in both samples was 30 μg/g DW. The size of the plant particles used for the extraction seems to contribute significantly to the exhibited activity.