Introduction. Propolis (bee glue) is a natural product collected by honeybees from buds of various trees, shrubs and other plant species. Extracts of propolis possess numerous biological activities, including antioxidant, antibacterial, antifungal and anticancer. For this reason, propolis is currently used in many applications, such as preparations for cold syndrome, dermatological preparations or as a constituent of nutritional supplements and health food. The chemical composition of this natural material is very complex and depending on many factors, including method of extraction and selection of the solvent for the extraction process. Aim. The aim of the study was to determine concentration of selected phenolic compounds (flavonoids and phenolic acids) in extract of Polish propolis and estimate its antioxidant activity and effect on human red blood cells. Material and methods. In the propolis extract was determined concentration of 14 flavonoids and 9 phenolic acids using ultra-performance liquid chromatography equipped with a photodiode detector and a triple quadrupole mass spectrometer. The antioxidant potential of propolis extract was evaluated applying DPPH˙ free radical scavenging activity assay and Fe3+ reducing power assay. Moreover, the cytotoxicity and cytoprotective potential of propolis extract was estimated using human erythrocytes in vitro. Results. The propolis extract contained high concentration of pinocembrin, galangin, chrysin, apigenin, kaempferol, coumaric acid and cinnamic acid. It exhibited also high antioxidant potential. The antiradical activity of examined propolis extract was equal to 75% approx. activity of both standard antioxidants used in the study, namely Trolox and BHT. The reducing power of extract was equal to 65% approx. of Trolox and 80% of BHT, respectively. The propolis extract had no hemolytic activity, moreover, effectively protected human erythrocytes against free radicals-induced damage in vitro. Conclusions. The results of this study indicate that the propolis extract of national origin is a rich source of flavonoids and phenolic acids. Therefore, the propolis extract possesses a high antioxidant potential and can protect erythrocytes against free radicals-induced oxidative hemolysis.
Comparative assessment of polyphenolics’ content, free radicals’ scavenging and cellular antioxidant potential in apricot ruit
