Comparative Antioxidant and Antimicrobial Activities of Several Conifer Needles and Bark Extracts
Diana Ionela Popescu (Stegarus),
Adina Frum,
Carmen Maximiliana Dobrea,
Ramona Cristea,
Felicia Gabriela Gligor,
Laura Gratiela Vicas,
Roxana Elena Ionete,
Nicoleta Anca Sutan,
Cecilia Georgescu
Affiliations
Diana Ionela Popescu (Stegarus)
National Research and Development Institute for Cryogenic and Isotopic Technologies—ICSI Ramnicu Valcea, 240050 Ramnicu Valcea, Romania
Adina Frum
Preclinical Department, Faculty of Medicine, “Lucian Blaga” University of Sibiu, 550169 Sibiu, Romania
Carmen Maximiliana Dobrea
Preclinical Department, Faculty of Medicine, “Lucian Blaga” University of Sibiu, 550169 Sibiu, Romania
Ramona Cristea
Department of Agricultural Sciences and Food Engineering, “Lucian Blaga” University of Sibiu, 550012 Sibiu, Romania
Felicia Gabriela Gligor
Preclinical Department, Faculty of Medicine, “Lucian Blaga” University of Sibiu, 550169 Sibiu, Romania
Laura Gratiela Vicas
Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410028 Oradea, Romania
Roxana Elena Ionete
National Research and Development Institute for Cryogenic and Isotopic Technologies—ICSI Ramnicu Valcea, 240050 Ramnicu Valcea, Romania
Nicoleta Anca Sutan
Department of Natural Sciences, Piteşti University Center, National University of Science and Technology Politechnica Bucharest, 110040 Pitesti, Romania
Cecilia Georgescu
Department of Agricultural Sciences and Food Engineering, “Lucian Blaga” University of Sibiu, 550012 Sibiu, Romania
Nowadays, an increased concern regarding using natural products for their health benefits can be observed. The aim of this study was to assess and compare several phenolic compounds found in 15- to 60-year-old Douglas fir, silver fir, larch, pine, and spruce needle and bark extracts and to evaluate their antioxidant and antimicrobial activities. Spectrophotometric assays were used to determine the total polyphenol content and the antioxidant activity that was assessed by using the DPPH• radical scavenging assay (RSA), the ferric reducing antioxidant power assay (FRAP), and the ABTS•+ radical cation scavenging assay (ABTS). The phytochemical content was determined by using high-performance liquid chromatography, and the antimicrobial activity was determined by assessing the minimal inhibition concentration (MIC). The results of the study show a total polyphenol content of 62.45–109.80 mg GAE/g d.w. and an antioxidant activity of 91.18–99.32% for RSA, 29.16–35.74 µmol TE/g d.w. for FRAP, and 38.23–53.57 µmol TE/g d.w. for ABTS. The greatest quantity of phenolic compound for most of the extracts was for (+)-catechin, and it had values between 165.79 and 5343.27 µg/g d.w. for these samples. The antimicrobial inhibition for all the extracts was the strongest for Staphylococcus aureus (MIC 62.5–125 µg/mL). The extracts analyzed could be used for their bioactive potential after further investigations.
