Antioxidant and antimicrobial activities of berries extracts of five Juniperus species under Juniperus section from Turkey

In Turkish folk medicine numerous Juniperus species, particularly those under the Juniperus section, are frequently employed to treat several diseases. This work was designed to evaluate the antioxidant and antimicrobial potential of methanol berries extracts of Juniperusspecies underJuniperus section from Turkey: Juniperuscommunis L. var. communis, Juniperuscommunis L. var. saxatili sPall., Juniperusdrupacea Labill., JuniperusoxycedrusL. subsp. oxycedrus, Juniperusoxycedru sL. subsp. macrocarpa (Sibth. & Sm.) Ball. The total phenolic content of Juniperus spp. extracts, evaluated by Folin-Ciocalteau method, ranged from 5.14 ± 0.06 mg GAE/g extract (Joo) to 59.17 ± 1.65 mg GAE/g extract (Jcc), and it decreased in the following order: Jcc>Jd>Jom = Jcs>Joo. The antioxidant properties of the extracts were examined in different in vitro systems. Jd showed the best activity in the DPPH (1,1-diphenyl-2-picrylhydrazyl) test (IC50=0.38 ± 0.02 mg/mL), in the Fe2+ chelating assay (IC50=2.26 ± 0.06 mg/mL), and in the TBA (ThiobarbituricAcid)test (IC50=2.47 ± 1.13 μg/mL); Jooresulted in the most active extract (4.05 ± 0.09 ASE/mL) in the reducing power assay. In addition, the antioxidant activity of the extracts was correlated to their phenolic content. The obtained results indicated that Juniperus spp. extracts possess both primary and secondary antioxidant activity; moreover, phenolic compounds appear to be responsible for the primary antioxidant effects. Since J. communis berries are traditionally used for their antiseptic action, it seemed interesting to evaluate the antimicrobial potential of all Juniperus spp. included in Juniperus section. The antimicrobial activity of Juniperus spp. extracts against bacteria and yeasts was evaluated by standard methods. The efficacy was appreciable on gram-positive only. Among the extracts Jd showed the higher bacteriostatic activity (MIC: 78.12-312.50 μg/mL) than Jcs and Jcc (MIC: 156.25-1250.00 μg/mL) followed by Joo and Jom(MIC: 625.00-1250.00 μg/mL). The Staphylococcus aureus wasthemost susceptible strain tested (MIC: 78.12-625.00 μg/mL). The results give a scientific basis to the traditional utilization of these Juniperus species, also demonstrating their potential as sources of natural antioxidant and antimicrobial compounds.