Antioxidant and Antimicrobial Activity of Polyphenol Extracts from Wild Berry Fruits Grown in Southeast Serbia

Purpose: To assess the antioxidant and antimicrobial activities of polyphenolic extracts of three wild red wild berry fruit species from Southeast Serbia, viz, European cornel ( Cornus mas ), blackthorn ( Prunus spinosa L.) and wild blackberry ( Rubus fruticosus ). Methods: Polyphenol content was determined using spectrophotometric and High performance liquid chromatography (HPLC) methods. Antioxidant activity was estimated by 2,2`- diphenyl - 1 - picrylhydrazyl (DPPH) test while reliminary antimicrobial tests were carried out by disc diffusion method in which antibacterial activity was evaluated by measuring the zone of inhibition against test bacterial strains. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Results: The highest amount of total phenols was found in European cornel (8625.89 mg kg-1FW). Galic acid, caffeic acid, p-coumaric acid, ferulic acid, (+)-catechin, procyanidin B2, (-)-epicatechin, quercetin, rutin and quercetin-3-glucoside were the main polyphenols in the fruit extracts. All extracts showed high scavenging effect on DPPH radical with IC50 values ranging from 22.19 to 31.18 ml g-1, as well as high antimicrobial activity on almost all the tested bacterial strains. Conclusion: Extracts of wild berry fruits may be suitable for the preparation of medicinal and nutritional products.