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Antioxidant and free radical scavenging activity of methanol, ethanol, ethyl acetate and chloroform extracts of aerial parts of Lamium purpureum L. was determined by DPPH, ABTS, FRAP and TRP assays. Contents of flavonoids and phenols were also investigated. The total phenolic content in the extracts, determined using Folin–Ciocalteu assay, ranged between 8.57 to 128.00 mg GAE/g d.e. while concentrations of flavonoids in the extracts varied from 24.20 to 39.80 mg QuE/g d.e. The highest phenolic content was found in methanol extract (128.00 mg GAE/g d.e.). The highest content of total flavonoids was identified in the methanol extract (39.80 mg QuE/g d.e.) and the lowest was in the chloroform (24.30 mg QuE/g d.e.). DPPH scavenging of the extracts was determined and obtained IC50 values ranged from 0.12 to 3.12 mg/mL of solution. The values of ABTS radical scavenging activity ranged from 0.35 to 1.80 mg AA/g. The highest ABTS antiradical activity was registered for methanol extract. The FRAP value was found within the range 0.08 to 1.04 μmol Fe/mg. The best radical scavenger was methanol (1.04 μmol Fe/mg). In reducing power assay different extracts of L. purpureum showed increasing of activity with increased concentration, and all extracts possessed substantial dose dependent antioxidant activity. The best reducing capacity was obtained with methanol extract of L. purpureum (0.0132 mg AA/mL). The results in this study confirmed that L. purpureum possesses moderate antioxidant properties.

This paper reports for the first time the effect of an acetone extract of Umbilicaria crustulosa on the micronucleus distribution of human lymphocytes, and on the cholinesterase activity and antioxidant activity by the cupric ion reducing antioxidant capacity (CUPRAC) method. Additionally, the total phenolic compounds (TPC) and the antioxidant properties were estimated via DPPH, ABTS and TRP assays. Moreover, the antibacterial activity against two Gram-positive and three Gram-negative bacteria were determined. Acetone extract of U. crustulosa at concentration of 1 and 2 μg mL-1 decreased a frequency of micronuclei (MN) by 10.8 and 16.8 %, respectively, acting more or slightly less than the synthetic protector amifostine (AMF, WR-2721, 11.4 %, at concentration of 1 μg mL-1). The tested extract did not inhibit cholinesterase activity nor did it exhibit activity toward the examined bacteria. The extract reduced the concentration of DPPH and ABTS radicals by 88.7 and 96.2 %, respectively. Values for total reducing power (TRP) and cupric reducing capacity (CUPRAC) were 0.6197±0.0166 μg ascorbic acid equivalents (AAE) per mg of dry extract, and 19.7641±1.6546 μg trolox equivalents (TE) per mg of dry extract, respectively. The total phenol content was 350.4188 ±14.587 μg gallic acid equivalents (GAE) per mg of dry extract. The results of the present study showed that U. crustulosa acetone extract is a promising candidate for in vivo experiments considering its antioxidant activity and protective effect on human lymphocytes. [Projekat Ministarstva nauke Republike Srbije, br. 172047]

This is the first study on antioxidant and antibacterial activity of essential oils of A. sylvestris and A. pancicii against the human pathogens. In the oil of A. sylvestris, the main compounds were limonene (75.3%) and α-pinene (9.6%), while in the oil of A. pancicii the main compounds were β-phellandrene (54.9%), α-pinene (14.5%) and α-phellandrene (4.05%). The results of ABTS have shown that antioxidant activity ranged between 1.48 and 2.07 mg VitC/g for 30 μL/mL of tested concentration. IC50 values in DPPH assay ranged between 59.895 and 149.498 mg/mL of tested concentrations. Antibacterial activity of the essential oils and antibiotics against pathogenic bacterial strains was investigated using microwell dilution method. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were in the ranges of MIC/MBC = 0.11/54.40 mg/mL and 0.10/48.20 mg/mL (respectively). When combined with antibiotics, the oils have exhibited synergism and may reduce the minimum effective dose of antibiotics required and minimize its side effects. [ABSTRACT FROM AUTHOR]

The chemical composition of the essential oil and the volatiles obtained by static headspace (HS) of Inula oculus-christi L. is presented. The GC-MS analysis of the hydrodistilled oil resulted in the identification of 90 components, representing 92.7% of the oil. The most abundant compounds were: caryophyllene oxide (9.8%), trans-longipinocarveol (9.2%), eucalyptol (7.3%) and intermedeol (6.2%). The major constituent of I. oculus-christi L. HS volatiles was eucalyptol (87.4%). The antioxidant activity was evaluated by four different methods: 2,2-diphenyl-1-picryl-hydrazylhydrate free radical assay (DPPH), 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method, total reducing power (TRP), ferric reducing antioxidant power (FRAP), and cupric reducing antioxidant capacity (CUPRAC). Total phenolic content in (TPC) examined oil was 177.95 µg GAE/mg oil. Radical scavenging potential of the oil was promising RSC-DPPH was 57.4% and RSC-ABTS was 82.7%. [ABSTRACT FROM AUTHOR]

This study reports for the first time in the chemical composition of acetone, ether, ethyl acetate and dichloromethane extracts of Hypogymnia tubulosa determined by HPLC-UV, GC-FID and GC-MS as well as effect of H. tubulosa acetone extract on micronucleus distribution on human lymphocytes and on cholinesterase activity. Additionally, antioxidant (estimated via DPPH, ABTS, TRP, CUPRAC and TPC assays) and antibacterial activity against two Gram-positive and three Gram-negative bacteria were also determined. The HPLC-UV analysis revealed the presence of depsidones, 3-hydroxyphysodic, 4-O-methyl physodic acid, physodic and physodalic acid together with two depsides, atranorin and chloroatranorin. GC-FID and GC-MS analyses enabled the identification of atranol, chloroatranol, atraric acid, olivetol, olivetonide and 3-hydroxyolivetonide as the main components. The results of present study show that H. tubulosa acetone extract is a promising candidate for in vivo experiments considering antioxidant activity. [ABSTRACT FROM AUTHOR]

Negative effects of available antibiotics and the constant development of bacterial resistance motivate a search for new antimicrobial agents. Aromatics plants have traditionally been used as antibacterial agents and are well accepted today as a source of antioxidants. The present study evaluated the antibacterial activities and antioxidant capacity of eight aromatic plants, indigenous to the flora of the Balkan Peninsula, which are used as medicinal plants in traditional medicine. The plants studied were Hyssopus officinalis , Angelica pancicii, Angelica sylvestris, Laserpitium latifolium , Achillea grandifolia, Achillea crithmifolia, Artemisia absinthium and Tanacetum parthenium . The antimicrobial activities of methanolic extracts of the plant tissues against 16 bacterial isolates of Escherichia coli , Pseudomonas aeruginosa , Klebsiella sp. , Proteus mirabilis , Acinetobacter sp. , Staphylococcus aureus , Streptococcus pyogenes , Streptococcus pneumoniae and Enterococcus faecalis were investigated using a microwell dilution assay. Minimal inhibitory concentration (MIC) of the extracts ranged from 6.3 to 100 mg mL -1 , and minimal bactericidal concentration (MBC) ranged from 12.5 to 100 mg mL -1 . Antioxidant potential of the extracts was analyzed as contents of total phenols and flavonoids; radical scavenging activity by the ABTS + and DPPH methods, and reducing power by the iron (III) to iron (II) reduction assay, and the ferric reducing antioxidant power assay (FRAP). Results of antioxidative activities from the 4 methods demonstrated similar sequence of activity: A. crithmifolia > A. grandifolia > H. officinalis > A. absinthium > T. parthenium > L. latifolium > A. pancicii > A. sylvestris. The total content of polyphenols and flavonoids in the methanol extracts of the studied species positively correlated with their antioxidant properties, confirming their major role in antioxidant activity of these species. [ABSTRACT FROM AUTHOR]

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Abstract: The in vitro antimicrobial and antioxidant activities of the crude methanol extracts of nine Hypericum species (H. barbatum Jacq., H. hirsutum L., H. linarioides Bosse, H. maculatum Crantz, H. olympicum L., H. perforatum L., H. richeri Vill., H. rumeliacum Boiss. and H. tetrapterum Fries) growing spontaneously in the Balkans were screened using a disk diffusion assay against a panel of standardized bacteria and fungi and a phosphomolybdenum method, respectively. The most active extract against all microbial strains was that of Hypericum hirsutum (collected at Vranjska Banja, South Serbia), which showed remarkable antimicrobial activity at a dose of 5μg per disk and a diameter of growth inhibition zone reaching values more than two times larger than that of standard antibiotics. The antimicrobial activity of H. barbatum, H. hirsutum, H. olympicum, H. richeri and H. tetrapterum has not hitherto been published. All the extracts possess a very broad spectrum of strong antimicrobial activity. All the investigated species, except H. perforatum, have been tested for the first time in an antioxidant capacity assay. The results are correlated and discussed with respect to the until now known constituents of the investigated species. [Copyright &y& Elsevier]