Bioactivity of Myrtus communis from the Montenegro coastline / Bioactividad de Myrtus communis del litoral de Montenegro

Although numerous studies have demonstrated the biomedical potential of Myrtus communis L., (Myrtaceae) data on myrt le from Montenegro are scarce. T o evaluate antioxidant, antimutagenic and antibacterial activity of myrtle methanolic extracts. Antioxidant activity was evaluated by measuring free radicals scavenging activity, reducing power and enzyme inhibition. The strongest scavenging activity was towards DPPH radical ( 2,2 - diphenyl - 1 - picry lhydrazyl) (IC 50 1.69 - 2.25 mg/mL) and superoxide anion (IC 50 0.56 to 0.88 mg/mL), followed by high reducing power (428 - 472 mgAA/g.DE) and inhibition of XOD (IC 50 0.308 - 0.6261mg/mL). Antimutagenic activity was evaluated in reverse mutation assays with Esche richia coli WP2 oxyR mutant IC202 and deficient in the induction of antioxidant enzymes. The myrtle extracts strongly inhibited mutagenesis induced by t - BOOH, reaching 70% at the highest concentration applied. Antimicrobial activity was examined on eight different bacterial strains. Gram - positive bacteria, S. epidermis , S. aureus and M. flavus demonstrated the highest sensitivity towards extracts (MICs 4.5 - 9 mg/mL), but significantly lower towards essential oil (MIC 0.42 - 3.32 mg/mL).

Aunque numerosos estudios han demostrado el potencial biomédico de Myrtus communis L., (Myrtaceae), los datos sobre el mirto de Montenegro son escasos. E valuar la actividad antioxidante, antimutagéni ca y antibacteriana de extractos metanólicos de mirto. La actividad antioxidante se evaluó midiendo la actividad de eliminación de radicales libres, el poder reductor y la inhibición enzimática. La actividad secuestrante más fuerte fue hacia DPPH radical ( IC 50 1.69 - 2.25 mg/mL) y radicales de anión superóxido (IC 50 0.56 a 0.88 mg/mL), seguido de alto poder reductor (428 - 472 m gAA/g.DE) e inhibición de XOD (I C 50 0,308 - 0,6261 mg/m L ). La actividad antimutagénica se evaluó en ensayos de mutación inversa con Esche richia coli WP2 oxyR mutante IC202 y deficiente en la inducción de enzimas antioxidantes. Los extractos de mirto inhibieron fuertemente la mutagénesis inducida por t - BOOH, alcanzando el 70% a la mayor concentración aplicada. La actividad antimicrobiana se examinó en octo cepas bacterianas diferentes. Las bacterias grampositivas, S. epidermis , S. aureus y M. flavus demostraron la sensibilidad más alta hacia los extractos (MIC 4.5 - 9 mg/mL), pero significativamente más baja hacia el aceite esencial (MIC 0.42 - 3 .32 mg/mL). Los resultados muestran la gran perspectiva nutrafarmacéutica de la especie montenegrina Myrtus communis .

Essential oil of Eucalyptus gunnii hook. As a novel source of antioxidant, antimutagenic and antibacterial agents.

The present study describes radical scavenging capacity (RSC), antimutagenic and antibacterial properties of the essential oil (EO) of the leaves of Eucalyptus gunnii Hook. (Southern Montenegro). Chemical composition was evaluated by gas chromatography-mass spectrometry (GC-MS). In oil, 1,8-cineole (67.8%) and α-pinene (14.12%) were the major compounds comprising almost 82% of total EO. EO exhibited moderate DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, with IC50 value of 7.19 µL/mL. The antimutagenic properties were assayed against the spontaneous and t-BOOH-induced mutagenesis in Escherichia coli IC202 oxyR mutant strain, deficient in removing radical oxygen species (ROS). Reduction of the spontaneous mutagenesis in the presence of E. gunnii EO was only slight, up to 12% at the highest concentration tested. However, when the oxidative mutagen was used, EO displayed more significant reduction of mutagenesis (maximum 23%) in a concentration dependent manner. Antibacterial activity was tested against the selected strains from ATTC and NCIB collections: Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, Bacillus subtilis, Micrococcus flavus, Klebsiella pneumoniae, and the two Escherichia coli strains from our laboratory collection (SY252 and IB112) using both the disk-diffusion and MIC assays. The greatest sensitivity was shown by M. flavus, K. pneumoniae and E. coli lpcA (MIC = 0.83 mg/mL), while the highest resistance was shown by E. coli (ATTC 25922) and S. epidermidis. This study represents the first report on chemical composition and biological activity of the Eucalyptus gunnii in the South Balkan region and beyond.

Essential oil of Myrtus communis L. as a potential antioxidant and antimutagenic agents.

The present study describes DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and antimutagenic properties of the essential oil of myrtle (Myrtus communis L.). Plant samples were collected from the two distant localities (southernmost and northern point) of the Montenegro coastline. Chemical profiles of the two samples were evaluated by GC-MS. In both of the samples monoterpenes were found to be the predominant compounds. Among them alpha-pinene, linalool, 1,8-cineole, and myrtenyl acetate were the major compounds. Significant differences between the samples were found in the ranges of alpha-pinene (14.7%-35.9%) and myrtenyl acetate (5.4%-21.6%). Both oils exhibited moderate DPPH scavenging activity, with IC50 values of 6.24 mg/mL and 5.99 mg/mL. The antimutagenic properties were assayed against spontaneous and t-BOOH-induced mutagenesis in Escherichia coli oxyR mutant IC202, a bacterial strain deficient in removing ROS. Reduction of the spontaneous mutagenesis in presence of myrtle EO was only slight, up to 13% at the highest concentration tested. When the oxidative mutagen was used, EO expressed higher reduction of mutagenesis, in a concentration dependent manner, with statistical significance for effect at the highest concentration tested (28%). Suppression of t-BOOH induced mutagenesis was correlated with the observed scavenging activity.