Antimicrobial activity of Satureja hortensis L. essential oil against pathogenic microbial strains

A hydro-distilled oil of Satureja hortensis L. was investigated for its antimicrobial activity against a panel of 11 bacterial and three fungal strains. The antimicrobial activity was determined using the disk-diffusion and broth microdilution methods. The essential oil of S. hortensis L. showed significant activity against a wide spectrum of Gram (-) bacteria (MIC/MBC=0.025-0.78/0.05-0.78 μl/ml) and Gram (+) bacteria (MIC/MBC=0.05-0.39/0.05-0.78 μl/ml), as well as against fungal strains (MIC/MBC=0.20/0.78 μl/ml). The results indicate that this oil can be used in food conservation, treatment of different diseases of humans, and also for the treatment of plants infected by phytopathogens

Antimicrobial and anti-inflammatory potential of different immortelle essential-oil chemotypes

Helichrysum italicum or immortelle (Asteraceae) essential oil has been widely used in alternative medicine for wound healing and other skin conditions such as hematoma and scars. It is possible that the therapeutic efficacy of this oil changes with the natural variability of the composition, i.e. existence of chemotypes, and due to various environmental factors (soil type, altitude, sun exposure, etc.) [1]. Herein we aimed to assess the relationship of the composition and the overall antimicrobial and anti-inflammatory potentials for 4 commercial immortelle oils containing differing amounts of neryl esters (23 : 43 : 12 : 21; oils 1, 2, 3, and 4, respectively), α-pinene (17 : 2 : 20 : 5), γ- and ar-curcumenes (19 : 14 : 16 : 15), and β-diketones (3 : 12 : 5 : 7). Oils 3 and 4 displayed higher antimicrobial activity compared to oils 1 and 2, showing a prominent anti-Staphylococcus aureus effect (MIC = 0.62 and 0.31 mg/mL, respectively). The tested strains were least susceptible (MIC ≥ 5 mg/mL) to the action of oil 1, rich in mono- and sesquiterpenic hydrocarbons. However, this oil, along with oil 3, showed the highest cytotoxicity toward macrophages (LC50 ~ 0.14 mg/mL). Among the oil chromatographic fractions, those enriched in α-pinene and curcumenes displayed the highest cytotoxicity, but were inferior to the toxicity of the oils. The statistical (PCA) treatment of the obtained composition-activity data implied that the observed differences in activities among the tested oils were not only due to the different amounts of the major constituents, but also due to the presence of minor constituents (e.g. 2-methylbutyl angelate in the case of the anti-staphylococcal activity of the oils). Interestingly, based on literature data, the constituents that displayed strong negative correlations in the PCA matrix possess a lower antimicrobial potential than the tested oils. We found that immortelle oil efficiency as antimicrobial and anti-inflammatory agents strongly depends on its composition and is an outcome of synergistic action between its constituents

Antimicrobial activity and cytotoxicity of commercial rosemary essential oil (Rosmarinus officinalis L.)

Rosemary is well known as a spice and widely used plant in ethnomedicine worldwide. In this paper, commercial essential oil of rosemary was tested for antimicrobial and cytotoxic activity together with its effect on germination. Antimicrobial activity testing showed moderate effect to both G-positive and Gnegative bacteria. In order to determine its effect to the cell membrane, spectrophotometric analysis was performed. It was determined that rosemary affects the cell membrane of bacteria. Cytotoxic activity of Rosmarinus officinalis essential oil had been evaluated. As a plant object, germinative bulbs of Allium cepa were used. Cytotoxic activity that corresponded to the concentration of essential oil was determined. It had been noticed that rosemary essential oil affected mitotic phase i.e. it significantly slowed down the mitosis. Also, investigation of rosemary essential oil's activity to germination was performed. It was determined that it had high effect to the germination. Concentration of 5 mg/ml completely inhibited the germination of Triticum vulgare

The influence of adding of flaxseed oil to sunflower oil on the content of tocopherols and carotenoids in blended edible oils

Blending vegetable oils of different composition and properties is one of the simplest methods for creating new specific products with the desired properties, which increases their commercial application and improves their nutritional quality. The effect of blending vegetable oils on tocopherols and carotenoids content was examined. Refined sunflower seed oil (S) and cold pressed flaxseed oil (F) were used in the experiment. These oils are blended in three different content of mass: sample 70S:30F (70% S and 30% F), sample 50S:50F (50% S and 50% F) and sample 30S:70F (30% S and 70% F). The results showed significant differences in the content of total tocopherols and total carotenoids between the two oils used for the preparation of three blended oils. Refined sunflower seed oil contains higher amounts of tocopherols and fewer amounts of carotenoids compared to cold pressed flaxseed oil in which the content of tocopherols is lower and the content of carotenoids is higher. In the obtained blends of edible vegetable oils, the content of total tocopherols ranged from 387.96 to 447.83 mg/kg while the determined total carotenoids content (as B-caroten) ranged from 3.11 to 5.63 mg/kg. By blending refined oil of sunflower seed and cold pressed oil of flax-seed, the balance of the parameters studied is contributed. The research in the work showed that the blending of vegetable oils provides the possibility of modulating their composition, and therefore of nutritive quality

Inhibitory effects of Ocimum basilicum and Salvia officinalis essential oils on virulence factors of Pseudomonas aeruginosa clinical isolates

Pseudomonas aeruginosa is a Gram-negative human opportunistic pathogen, responsible for a variety of human health disorders. The virulence of each P. aeruginosa strain is strongly related to its capability of biofilm formation, different types of motility, production of toxins and pigments. Essential oils of basil and sage have a wide range of applications in the traditional and/or official medicine. The aim of the present study was to evaluate the activity of basil (Ocimum basilicum) and sage (Salvia officinalis) commercially available essential oils on P. aeruginosa virulence factors (post-adherence biofilm production, resistance of a mature biofilm, motility and production of pyocyanin). Antipseudomonal efficacy was studied using the microdilution method and the obtained minimal inhibitory concentrations (MICs) were further used to explore the anti-virulence potential. The experiments were performed against a panel of P. aeruginosa clinical isolates of different origin at 1/2 x MIC, MIC, and 2 x MIC concentrations.                The two essential oils were chemically characterized by GC and GS/MS analyses, where linalool and (E)-anethole where found to be the dominant compounds in the basil oil sample, while α-thujone and camphor were the major constituents of the sage essential oil sample. The biofilm experiments demonstrated a very high activity of both oils to biofilm production, where basil oil showed a higher efficiency by inhibiting up to 92.7% of the biofilm produced by the control, while sage oil exhibited a reduction of 9.8 to 76.8%. Promising results were also obtained when the oils were applied to mature biofilms, where reductions of 2.4-84.1% and 13.8-75.8% were measured for basil and sage oils, respectively. The results on motility evaluation showed that, in the presence of both oils, swimming, swarming and twitching motility patterns were significantly affected. Experiments on the pyocyanin production showed a reduction from 20.7-60.9% and 5.0-60.5% caused by the basil and sage oils, respectively.                Considering all the obtained results, it can be concluded that both basil and sage essential oils present highly efficient antipseudomonal agents which could be used against infections caused by this pathogen

Anticandidal activity of Inula helenium root essential oil: synergistic potential, anti-virulence efficacy, and mechanism of action

Inula helenium L. (elecampane) is a widely occurring perennial plant species in Europe and East Asia, belonging to the Compositae family. Roots of I. helenium have been traditionally used for the treatment of various diseases and it is officially listed in pharmacopeias as a diuretic, diaphoretic, expectorant and anthelmintic [1]. The present study investigated the anticandidal potential of I. helenium essential oil, isolated from roots and chemically characterized by GC and GC/MS. Antifungal efficacy was studied using the microdilution method and the determined minimal inhibitory concentrations (MICs) were further used to study a potential synergistic interaction of the oil and an antifungal. Together with this, the mode of action (sorbitol and cholesterol assays) and anti-virulence effects (antibiofilm, germ-tube reducing and phospholipase-inhibitory activities) were also investigated.                The results showed that the isolated essential oil contained alantolactone and isoalantolactone as the dominant constituents (65.8 and 25.5%, respectively). The obtained MICs varied among the strains, but the oil generally exhibited a high anticandidal potential (0.009-0.312 mg/mL). The oil displayed a high synergistic effect in combination with the antifungal agent nystatin. Experiments on the mode of action demonstrated that the oil affected the cell membrane function, due to the enhancement of the oil's activity (lowering of active concentrations) in the presence of sorbitol and cholesterol. Considering the virulence factors, the oil exhibited an antibiofilm activity, as well as a very high germ-tube reducing potential (93.3-100% at MIC). Additionally, a complete inhibition of the enzyme phospholipase in the presence of I. helenium root essential oil was demonstrated.                Based on the presented results, the essential oil of I. helenium can be considered as a good candidate for a natural agent that can be further explored in the sense of candidiasis treatment

Postharvest changes of rapeseed oil quality as affected by storage conditions

The aim of this study was to test whether variations in storage conditions throughout one year affect quality of oil of five different rapeseed genotypes (NS Vid, NS Pek, AMJ3, Traviata, NS Ras) harvested from three localities in Serbia (Pancevo, Rimski Sancevi, Sombor). Harvested seeds were stored in a cold room with invariable conditions (4±1°C, 60% humidity) and store room with variable conditions (up to 5°C higher than environmental). Oil samples were obtained by cold pressing rapeseed 0, 6 and 12 months after the harvest and further analyses were performed to monitor content and composition of fatty acids, tocopherols and antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl radical scavenging activity assay). The fatty acid composition was determined by gas chromatography coupled with a flame ionizing detector after derivatization to their volatile methyl esters. Quantification of tocopherols was carried out using high performance liquid chromatography with fluorescence detection

Lista prihvaćenih znanstvenih projekata - 1. ciklus (2. dio)

Lista prihvaćenih znanstvenih projekata - 1. ciklus (2. dio

Potential Phytopharmacy and Food Applications of Capsicum spp.: A Comprehensive Review

Capsicum genus (Solanaceae) is native to the Americas. Today, it is an important agricultural crop cultivated around the world, not only due to its economic importance, but also for the nutritional value of the fruits. Among their phytochemical constituents, capsaicinoids are characteristic and responsible of the pungency of sharp-tasting cultivars. Moreover, Capsicum and capsaicinoids (mainly, capsaicin) have been largely studied because of their health benefits. Thus, this study reviews the scientific knowledge about Capsicum spp. and their phytochemicals against cancer, diabetes, gastrointestinal diseases, pain, and metabolic syndrome, as well as their antioxidant and antimicrobial activity. These bioactivities can be the basis of the formulation of functional ingredients and natural preservatives containing Capsicum extracts or isolated compounds

A small library of 4-(alkylamino)-3-nitrocoumarin derivatives with potent antimicrobial activity against gastrointestinal pathogens

Due to a confirmed antimicrobial activity of both natural and synthetic coumarin derivatives, the present study was envisaged to provide a further insight into the antimicrobial potential of coumarins through a screening of a designed library of nine 4-(alkylamino)-3-nitrocoumarins against a panel of 24 laboratory strains and resistant (isolates) bacterial and fungal pathogens. All compounds showed some degree of strain-selective activity, that was, in some cases, very pronounced, reaching the value of 0.04 nmol/ml (i.e. 12 ng/ml) for the minimal inhibitory concentration against Candida albicans. The observed activity was higher against Gram-negative strains, among which the most susceptible strain, among both ATCC strains and clinical isolates, was Salmonella enteritidis. These results point out to a high potential of these coumarins as antimicrobials for the treatment of gastrointestinal and other infections caused by highly resistant microbial strains. Finally, a multivariate statistical analysis of the herein obtained and previous results on the antimicrobial activity of related selected coumarins was performed to allow an easier structure-activity discussion. [Projekat Ministartsva nauke republike Srbije, br. 172061 i br. 45022