Juniperus oxycedrus L. subsp. oxycedrus and Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. "berries" from Turkey: comparative evaluation of phenolic profile, antioxidant, cytotoxic and antimicrobial activities.

This work aimed to evaluate and compare the phenolic profile and some biological properties of the ripe "berries" methanol extracts of Juniperus oxycedrus L. subsp. oxycedrus (Joo) and Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom) from Turkey. The total phenolic content resulted about 3-fold higher in Jom (17.89±0.23 mg GAE/g extract) than in Joo (5.14±0.06 mg GAE/g extract). The HPLC-DAD-ESI-MS analysis revealed a similar flavonoid fingerprint in Joo and Jom, whereas a difference in their quantitative content was found (4632 µg/g extract and 12644 µg/g extract). In addition, three phenolic acids were detected in Jom only (5765 µg/g extract), and protocatechuic acid was the most abundant one. The antioxidant capacity of the extracts was evaluated by different in vitro assays: in the DPPH and in the TBA tests a stronger activity in Jom was highlighted, while Joo exhibited higher reducing power and metal chelating activity. Joo and Jom did not affect HepG2 cell viability and both extracts resulted virtually non-toxic against Artemia salina. The extracts were also studied for their antimicrobial potential, displaying efficacy against Gram-positive bacteria.

Antioxidant and antimicrobial activities of branches extracts of five Juniperus species from Turkey.

CONTEXT: Several Juniperus species (Cupressaceae) are utilized in folk medicine in the treatment of infections and skin diseases. OBJECTIVE: This work was designed to evaluate the antioxidant and antimicrobial potential of methanol and water branches extracts of Juniperus species from Turkey: Juniperus communis L. var. communis (Jcc), Juniperus communis L. var. saxatilis Pall. (Jcs), Juniperus drupacea Labill. (Jd), Juniperus oxycedrus L. subsp. oxycedrus (Joo), Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom). MATERIALS AND METHODS: Total phenolics, total flavonoids and condensed tannins were spectrophotometrically determined. The antioxidant properties were examined using different in vitro systems. The toxicity was assayed by Artemia salina lethality test. The antimicrobial potential against bacteria and yeasts was evaluated using minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC) measurements. The effect on bacteria biofilms was tested by microtiter plate assay. RESULTS: Both in the DPPH (1,1-diphenyl-2-picrylhydrazyl) and TBA (thiobarbituric acid) test Jom resulted the most active (IC(50) = 0.034 ± 0.002 mg/mL and 0.287 ± 0.166 µg/mL). Joo exhibited the highest reducing power (1.78 ± 0.04 ASE/mL) and Fe(2+) chelating activity (IC(50) = 0.537 ± 0.006 mg/mL). A positive correlation between primary antioxidant activity and phenolic content was found. The extracts were potentially non-toxic against Artemia salina. They showed the best antimicrobial (MIC = 4.88-30.10 µg/mL) and anti-biofilm activity (60-84%) against S. aureus. DISCUSSION AND CONCLUSION: 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.

In vitro effect of branch extracts of Juniperus species from Turkey on Staphylococcus aureus biofilm.

Methanol and aqueous branch extracts of five Juniperus species were examined for their effects on Staphylococcus aureus ATCC 6538P and S. aureus 810 biofilm. The Turkish plant material was Juniperus communis L. var. communis, J. communis L. var. saxatilis Pall., Juniperus drupacea Labill., Juniperus oxycedrus L. ssp. oxycedrus, J. oxycedrus L. ssp. macrocarpa (Sibth. & Sm.) Ball. The Juniperus extracts were subjected to preliminary phytochemical analysis by thin-layer chromatography. The antimicrobial activity was evaluated using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The effects of the extracts on biofilm formation and preformed biofilm were quantified by both biomass OD and the CFU counting method. The phytochemical screening revealed the presence of polyphenols, coumarins, lignans, steroids, alkaloids and terpenes. For both strains, the MICs of all extracts were in the range of 4.88-78.12 microg mL(-1). On S. aureus ATCC 6538P, the effects of subinhibitory concentration (0.5 MIC) of the extracts were minimal on planktonic growth and on adhering cells, whereas they were greater on biofilm formation. Differently, on S. aureus 810, they showed only a rather low efficacy on biofilm formation. The extracts at 2 MIC demonstrated a good activity on a preformed biofilm of S. aureus ATCC 6538P.

Comparative analysis of flavonoid profile, antioxidant and antimicrobial activity of the berries of Juniperus communis L. var. communis and Juniperus communis L. var. saxatilis Pall. from Turkey.

The present study was designed to define and compare the flavonoid composition and the biological potential of berries methanol extracts of Juniperus communis L. var. communis (Jcc) and Juniperus communis L. var. saxatilis. Pall. (Jcs) from Turkey. Total polyphenols (Folin-Ciocalteau method) were 3-fold higher in Jcc (59.17 +/- 1.65 mg GAE/g extract) than in Jcs (17.64 +/- 0.09 mg GAE/g extract). Flavonoid and biflavonoid content, evaluated by HPLC-DAD-ESI-MS analysis, was higher in Jcc (25947 +/- 0.86 and 4346 +/- 3.95 microg/g extract) than in Jcs (5387 +/- 34.88 and 1944 +/- 26.88 microg/g extract). The HPLC analysis of Jcc allowed the separation of 16 flavonoids; hypolaetin-7-pentoside and quercetin-hexoside are the main compounds. Moreover, gossypetin-hexoside-pentoside and gossypetin-hexoside were identified for the first time in Jcc berries. In Jcs eight flavonoids were identified: quercetin-hexoside and isoscutellarein-8-O-hexoside are the most abundant compounds. The in vitro antioxidant activity was determined using different methods; Jcc was found to be more active than Jcs in the DPPH test (IC(50) of 0.63 +/- 0.09 mg/mL and 1.84 +/- 0.10 mg/mL) in reducing power assay (12.82 +/- 0.10 ASE/mL and 64.14 +/- 1.20 ASE/mL), and in TBA assay (IC(50) of 4.44 +/- 0.70 microg/mL and 120.07 +/- 3.60 microg/mL). By contrast, Jcs exhibited more elevated Fe(2+) chelating ability than Jcc. The extracts were also studied for their antimicrobial potential, displaying antimicrobial capacity only against Gram-positive bacteria.