Sage Oil Research Articles

In Vitro Antibacterial Activity of Some Plant Essential Oils against Four Different Microbial Strains

This study evaluates the antimicrobial and antioxidant activities of five essential oils (EO): pine oil, thyme oil, sage oil, fennel oil, and eucalyptus essential oils. To identify the chemical composition of the essential oils, we used gas chromatography coupled to a mass spectrometer (GC-MS). EO are predominantly characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpenes, except in the case of fennel essential oil which contains phenylpropanoids as its main components. The antimicrobial activity of the EO was highlighted on four standard microbial strains (two Gram-negative strains-Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853; one Gram-positive strain Staphylococcus aureus ATCC 25923, and one yeast strain-Candida albicans ATCC 10231). Antimicrobial activity was assessed by measuring the diameter of the inhibition zone, and by determining the values of the minimum inhibitory concentration (MIC) and minimum concentration of biofilm eradication (MCBE). Analyzing the diameter values of the inhibition zones we observed increased efficiency of thyme essential oil, which showed the highest values for all tested microbial species. The results of tests performed in a liquid confirm the high sensitivity of the standard strain Escherichia coli ATCC 25922 to the action of all essential oils, the lowest values of MIC being recorded for sage and thyme essential oils. For the most essential oils tested in this study, the MCBE values are close to the MIC values, except for the pine EO which seems to have stimulated the adhesion of the yeast strain at concentrations lower than 5%. The study highlights the antimicrobial activity of the tested essential oils on Gram-positive and Gram-negative strains.

Transdermal Absorption of Sclareol, an Active Ingredient in Clary Sage Oil: A Complementary and Alternative Medicine for Menopausal Symptoms

Clary sage oil is commonly used in complementary and alternative medicine to treat menopausal symptoms. However, whether sclareol, which is considered to have estrogen-like effects, can be absorbed transdermally remains unknown. Therefore, in this study, we applied sclareol dissolved in jojoba oil to the dorsal skin of male Hos-HR-1 mice 30 min before blood sampling. We examined whether sclareol can be detected in the plasma because of transdermal absorption using gas chromatography-mass spectrometry analysis. The concentration of sclareol in plasma and liver samples calculated based on the measured sample concentration and the recovery rate was 0.36 ± 0.08 and 1.69 ± 0.32 ppm, respectively. Furthermore, there was a significant positive correlation between the plasma sclareol concentration and hepatic homogenate sclareol concentration. Our findings indicate that sclareol is absorbed transdermally and accumulates in the liver. Moreover, the lack of change in plasma blood urea nitrogen, aspartate aminotransferase, and alanine aminotransferase levels among the three groups indicates that there was no hepatic or renal damage due to transdermal absorption of sclareol in Hos-HR-1 mice. However, further validation in humans is required because the thickness of the dermis and the number of pores significantly differ between mice and humans.

Bioefficacy of pumpkin (Cucurbita pepo L.), sage (Salvia officinalis L.), and sesame (Sesamum indicum L.) essential oils as defense inducers of faba bean against rust disease

Bioefficacy of pumpkin (Cucurbita pepo L.), sage (Salvia officinalis L.), and sesame (Sesamum indicum L.) essential oils as defense inducers of faba bean against rust disease

Effectiveness of Herbal Essential Oils as Single and Combined Repellents against Aedes aegypti, Anopheles dirus and Culex quinquefasciatus (Diptera: Culicidae).

Simple SummaryThe repellent efficacy of ten essential oils was measured against all three-mosquito species using the arm-in-cage approach to determine the duration of protection. All essential oils showed high complete-protection time against Culex quinquefasciatus, ranging from 120 to 360 min. Petitgrain oil showed the highest complete-protection time from bites of Aedes aegypti for 270 min. Peppermint oil also exhibited complete-protection time from bites of Anopheles dirus for 180 min. When two highly effective essential oils were combined to potentially prolong mosquito bite protection, the binary combinations of petitgrain with other essential oils (basil and coriander) exhibited antagonistic effects and provided complete protection against A. aegypti bite for 150 min. On the other hand, the sage and patchouli oil combination showed more repellent activity from A. dirus bite for 270 min than an individual oil. The binary combination efficiently increased or decreased protection time.Mosquito repellents reduce human-vector contact of vector-borne diseases. We compared the repellent activity of 10 undiluted essential oils (anise, basil, bergamot, coriander, patchouli, peppermint, petitgrain, rosemary, sage and vetiver) against A. aegypti, A. dirus and C. quinquefasciatus using the arm-in-cage method. Petitgrain oil was the most effective against A. aegypti (270 min). Peppermint oil was the most effective against A. dirus (180 min). Interestingly, all single oils had attributes of repellency against C. quinquefasciatus (ranged, 120–360 min). Moreover, we integrated their binary combinations of highly effective essential oils against A. aegypti and A. dirus to potentially increase the protection time. A 1:1 combination of petitgrain/basil, petitgrain/coriander, basil/coriander and basil/sage reduced the median complete-protection time of 150 min for A. aegypti; a combination of sage and patchouli oils prolonged the median complete-protection time of 270 min for A. dirus. Combining essential oils effect protection time from these two mosquito species.

Effects of Olfactory Stimulation with Aroma Oils on Psychophysiological Responses of Female Adults.

This study investigated the effects of olfactory stimulation with aroma oils on the psychophysiological responses in women. Ten aromatic oils (lavender, rosemary, rose, eucalyptus, jasmine, geranium, chamomile, clary sage, thyme, and peppermint) were used on 23 women aged between 20 and 60 years. They inhaled the scent for 90 s through a glass funnel attached to their lab apron, 10 cm below their nose, while the pump was activated. Electroencephalography, blood pressure, and pulse rate were measured before and during inhalation of the aroma oils. The relative alpha (RA) power spectrums indicating relaxation and resting state of the brain significantly increased when lavender, rosemary, eucalyptus, jasmine, chamomile, clary sage, and thyme oils were inhaled compared to those of before olfactory stimulation. The ratio of alpha to high beta (RAHB), an indicator of brain stability and relaxation, significantly increased when rosemary, jasmine, clary sage, and peppermint oils were inhaled. The relative low beta (RLB) power spectrum, an indicator of brain activity in the absence of stress, significantly increased when stimulated with lavender, rosemary, rose, and geranium scents. Further, systolic blood pressure significantly decreased after introduction of all 10 types of aromatic oils, which indicates stress reduction. Thus, olfactory stimulation with aroma oil had a stabilizing effect on the prefrontal cortex and brain activity and decreased systolic blood pressure.

Possibilities of syndrome-oriented medical rehabilitation in diseases of the respiratory organs in the resort of the Southern coast of Crimea

Aim. To evaluate the possibilities of physiotherapeutic syndrome-oriented medical rehabilitation (MR) for lung diseases (LD) in the climatic resort of the Southern Coast of Crimea (SCC). Materials and methods. In a single-center retrospective observational study, an analysis was made of the rehabilitation effects of physiotherapeutic interventions in a contingent of 100 patients with LD. Examination and treatment of patients was carried out in accordance with the standard of health resort care for patients with LD. Additionally, psychological studies and therapeutic effects were carried out by transcranial electrical stimulation, dynamic electrical nerve stimulation, mud therapy with Saki therapeutic mud, aromatherapy with sage oil and breathing training with a breathing simulator “New Breath”. The assessment of the values of 23 domains of “International Classification of Functioning, Disability and Health” (ICF) was carried out according to the methodology developed in the “ARI n.a. I.M.Sechenov”. The values of domains at the beginning and at the end of the MR course were evaluated, as well as the dynamics of domains (equal to the result of subtracting the values of the domain at the end of the course from the value at the beginning of the course). Mathematical analysis of the obtaineddata was carried out using the methods of multivariate statistics. Results. A statistically significant (at p < 0.05) positive dynamics of a number of domains was established, indicating the success of a comprehensive course of MR, including domains b2401, b410, b420, b450, b455, b4552, b4601 and an integrated assessment of the functional state (IAFS). The 18 equations of the positive effect of course doses of physiotherapeutic procedures (alternating magnetic field, DENS, ultrasound therapy, halotherapy, inhalation therapy, aromatherapy, pelopathy, short-wave ultraviolet irradiation and massage) on the effectiveness of MR for 12 domains and for IAFS were obtained. Conclusion. The use of ICF domains as rehabilitation syndromes is substantiated. The complex of physiotherapeutic influences used in the treatment of patients with LD in the SCC climatic resort has significant potential for successful syndrome-oriented MR.

BIOLOGICAL ACTIVITY OF ESSENTIAL SAGE OIL

Essential sage oil (ESO) was isolated from dry leaves by steam distillation with Neo-Clevenger apparatus. The chemical analysis of the ESO consisted in the assessment of the total polyphenolic content (Folin-Ciocâlteu method) and of the radical scavenging activity with DPPH. The antioxidant activity was measured using two standard compounds: gallic acid and ascorbic acid. Phenolic content of essential oil of S. officinalis was significant (15.465 mg GAE/g oil) and antioxidant activity was high. Antibacterial activity of essential sage oil was evaluated against Gram positive and Gram-negative bacterial strains isolated from clinical specimens. The sage oil showed significant but variable antibacterial activity with inhibition zones ranging from 4 mm to 9.5.mm. The effect was stronger on Gram positive (Enterococcus, Staplylococcus) than Gram negative bacteria (Escherichia sp, Proteus sp, Klebsiella sp).

Antimicrobial and Anti-Colorectal Cancer Activities of Some Volatile Oils

Volatile oils are natural compounds that can be adopted in many drug and cosmetic formulations. Many volatile oils can be extracted from natural plants and they have their own special biological activities. Nine volatile oils including pine oil (P), guava leaf oil (G), lime peel oil (L), cinnamon bark oil (C), sage oil (S), tea tree oil (T) rosemary oil (R), clove oil (CL) and jasmine sambac oil (J) were in vitro tested for anti-microbial activities against various microbes and cytotoxicity properties agianst HCT116 and HT29 cell lines. From our result, for antimicrobial activities, the most effective oil against Gram positive such as Staphylococcus aureus are T, R and L. Only P showed the great inhibition on Gram negative bacteria such as Escherichia coli. C, P, L, T and R also exhibited different inhibitory effects on the pathogenic yeasts depending on the candida species. For the antitumoral activity on colorectal cancer cell lines, C showed the most cytotoxicity on both HCT116 and HT29 cells with IC50 value of 7.7 and 74.0 μg/ml, respectively. The second most cytotoxic was guava oil with the IC50 of 101.2 and 97.91 μg/ml on HCT116 and HT29, respectively. These investigated data may be useful as information for oil selection and development of pharmaceutical dosage forms using these natural volatile oils as the ingredients.

Evaluation of the Antibacterial Effect of Salvia Officinalis Essential Oil and its Synergistic Effect with Meropenem

Warnings by WHO concerning the antibacterial resistance was an encouragement to investigate the antibacterial effects of extracted and purchased Salvia officinalis essential oils against S. aureus, L. monocytogenes, S. pyogenes, E. coli, P. aeruginosa, and K. pneumonia by the agar well diffusion method. Besides, the checkerboard method evaluated the potential synergistic antibacterial activity of volatile sage oil and meropenem against multi-drug resistant E. coli. Results showed that the purchased oil did not have antimicrobial activity against any of the tested pathogens, while the extracted oil of S. officinalis inhibited the growth of all the tested microorganisms except the MDR K. pneumonia. The extracted oil showed the highest activity against the E. coli with an IZ of 18±0.4 mm and MIC of 6.25± 0.2 mg/ml, and the lowest activity was recorded against P. aeruginosa with an IZ of 10±0.2 mm and MIC of 25 mg/ml. In addition, SoEO showed a promising synergistic effect with meropenem against MDR E. coli. Results suggest that the EOs of S. officinalis possess antimicrobial activity, and therefore, they can be used to treat infections caused by some pathogens.

In Vitro Potential of Clary Sage and Coriander Essential Oils as Crop Protection and Post-Harvest Decay Control Products.

Owing to their various application fields and biological properties, natural products and essential oils (EO) in particular are nowadays attracting more attention as alternative methods to control plant pathogens and pests, weeds, and for post-harvest applications. Additionally, to overcome EO stability issues and low persistence of effects, EO encapsulation in β-cyclodextrin (β-CD) could represent a promising avenue. Thus, in this work, the EO distilled from two aromatic plants (Salvia sclarea L. and Coriandrum sativum L.) have been evaluated in vitro for their antifungal, herbicidal and insecticidal activities, against major plant pathogens and pests of agronomical importance. Both plants were grown on unpolluted and trace-element-polluted soils, so as to investigate the effect of the soil pollution on the EO compositions and biological effects. These EO are rich in oxygenated monoterpenes (clary sage and coriander seeds EO), or aliphatic aldehydes (coriander aerial parts EO), and were unaltered by the soil pollution. The tested EO successfully inhibited the growth of two phytopathogenic fungi, Zymoseptoria tritici and Fusarium culmorum, displaying IC50 ranging from 0.46 to 2.08 g L−1, while also exerting anti-germinative, herbicidal, repellent and fumigant effects. However, no improvement of the EO biological effects was observed in the presence of β-CD, under these in vitro experimental conditions. Among the tested EO, the one from aerial parts of coriander displayed the most significant antifungal and herbicidal effects, while the three of them exerted valuable broad-range insecticidal effects. As a whole, these findings suggest that EO produced on polluted areas can be of great interest to the agricultural area, given their faithful chemical compositions and valuable biological effects.

Efficacy of essential oils in the management of soft rot caused by Pectobacterium aroidearum in lettuce

Lettuce is susceptible to several diseases, especially soft rot caused by bacteria of the genus Pectobacterium. Due to the adaptability of this pathogen and the lack of disease control registered for the crop, the objective of this work was to evaluate the effects of essential oils in the management of soft rot caused by P. aroidearum in lettuce. The study was developed at the Universidade do Estado da Bahia, Juazeiro, BA, Brazil, and the essential oils (EOs) of orange, bergamot, lemongrass, palmarosa, citronella, cloves, tea tree, rosemary, sage, and ginger were used in concentrations of 0.25; 0.5; 0.75 and 1.0% to assess the in vitro growth inhibition of the bacterium. Subsequently, the curative effects of the disease were evaluated by applying the EOs that obtained the best results in vitro in lettuce plants of the susceptible variety “Mônica”. The treatments were applied, via spraying, 12 hours after inoculation using the bite method with bacterial suspension. The best in vivo treatment was selected to assess its preventive and curative activity, as well as to find the ideal concentration for reducing epidemiological variables and chromatographic characterization. The EOs of palmarosa, sage, citronella, lemongrass, and cloves (0.25%), and that of sage (0.75%), inhibited bacterial growth in vitro. The EO of salvia showed the best results in vivo, inhibiting the growth of the disease in concentrations of 0.50 and 0.75%, so it was selected for the preventive and curative control tests alone. The preventive treatment was not efficient for the management of soft rot in lettuce, however, from the regression analysis, a concentration of 0.64% of the salvia EO was found as a potential for curative control of this bacteriosis, as it reduces the incidence and severity of the disease. Linalyl acetate and linalool were found in higher concentrations in the chromatographic analysis. These components, probably, conferred the bactericidal capacity of the EO of sage, being potential for the use in the control of P. aroidearum in lettuce.

Effect of different plants’ aromatic essential oils on frozen Awassi lamb meat’s chemical and physical characteristics

The effect of drenching Awassi lambs with three aromatic essential oils from sage (Salvia officinalis L.), clove (Syzygium aromaticum L.), and laurel (Laurus nobilis L.) was investigated on meat chemical and physical characteristics, and oxidative and deterioration measurements. Twenty-four Awassi lambs, five to six months old, were divided into four groups. A concentrated diet was provided to the lambs at a rate of 3% of the body weight. The treatments were as follows: T1 was served as the untreated control, while T2, T3, and T4 were drenched with oils of sage, clove, and laurel, respectively. Drenching was carried out using water-soluble capsules containing 500 mg oil/capsule/day. Treatments lasted 90 days. At the end of the treatment period, the animals were fasted overnight and slaughtered. The carcasses were cleaned and kept at 4°C for 24 h. The longissimus dorsi (LD) muscle was then separated and preserved in a plastic bag for three preservation periods: no freezing and 30 days and 60 days freezing at −18°C. Several physical, fat, and protein stability analyses of meat were done after the preservation periods. The results indicated no significant effect of drenching Awassi lambs with different aromatic essential oils on the meat’s physical and chemical characteristics. However, these oils, especially clove oil, affected fat and protein stability with increasing preservation period by freezing.

Water solubility of clary sage essential oil

The article provides data on the degree of solubility of essential oils in water. Essential oils are considered as compounds that are completely insoluble or slightly soluble, or refer to substances with a certain, limited, solubility. The distillation of the essential oil from the raw material is preceded by its dissolution in water and hydrodiffusion in the solution beyond the limits of the essential oil containers. The solubility of essential oils in water, apparently, plays an important role in living plants during their intracellular movement and removal outside the cells. To clarify the concepts, samples of primary and secondary oils obtained in production have been examined. The solubility of clary sage oil at 20○C reaches a significant value (0.094% for primary one, 0.406% for secondary one), but with an increase in temperature up to 40○C it decreases to 17-15%. Further study of the GLC data shows that the change in the percentage is due to an increase in the content of cineole and unidentified components in the oil, which have a relatively high solubility, hardly noticeable in the primary oil and accumulate in the secondary one and in the one isolated from the primary one. In the sample isolated from the water solution of the secondary oil there are 2 unidentified components located between cineole and linalool and apparently having increased solubility. Due to this, the percentage of linalool in the oil isolated from the solution decreases, but the absolute amount of the latter in 100 ml of the solution increases 2,58 times compared to the oil isolated from the primary oil solution.

Chemical Composition of Essential Oils Isolated from Aerial Parts of Some Wild Herbs Growing in Arid Regions of Egypt

Essential oils are affected by botanical origins which can induce variations in their chemical components and biological activities. Therefore, discovering the same plants from many regions leads to an increase and diversification of essential oil sources as one of the natural products that are used for many purposes. Four wild Lamiaceae plants (sage, micromeria, marrubium and thyme) were collected from arid regions in Egypt and their essential oils were evaluated. Essential oil contents of sage, micromeria, marrubium and thyme recorded the values of 0.5, 0.1, 0.1 and 1.7 %, respectively. The major components of sage essential oil are germacrene-B, geranyl linalool, 2, 6, 8-eudesmatriene, β-elemene, germacrene-D, α-guaiene, graniol, aromadendrene, β-cadinene and δ-cadinene. Caryophyllene oxide, α-bisabolol, humulene epoxide III, patchulane and Z-α-trans-bergamotol were the main components of micromeria essential oil. The major constituents of marrubium essential oil are thymol, myristicin, 1-undecene, isomenthol, E-phytol, germacrene-D and bornyl acetate. Thymol was the main component of thyme essential oil. Sesquiterpene hydrocarbons and oxygenated sesquiterpenes were the major chemical group of sage and micromeria essential oils, respectively; whereas, oxygenated monoterpenes were the main group of marrubium and thyme essential oils. This study concludes that sage, micromeria, marrubium and thyme plants growing in arid regions are new sources of essential oils.

Using of Different Kinds of Aromatic Oils with Feeding on Some Productive Traits in Awassi Lambs

This study was conducted in the animal farm of the College of Veterinary Medicine/Tikrit University for the period from 01/10/2019 to 31/12/2019 to investigate the effect of using different kinds of aromatic oils on some productive traits in Awassi lambs. Twenty Awassi lambs aged between 5-6 month and divided according to weight into four group and hens in an individual cages, the study lasted for 90 day. concentrate diet provided to the lambs at 3% of their body weight. the treatment were as follows : T1 was a control group without drenching, T2 drenched with sage oil, T3 drenched with clove oil and T4 drenched with laurel oil. drenching process was done manually by using water-soluble capsules each one contain 500 mg of oil, each lambs was given one capsule/day. which is pushed by using a plastic tube in to the beginning of esophagus. to study the effect of these oils on weight characteristics, body dimensions and wool characteristics. The results showed that there was no significant effect of the treatments on body weight characteristics. As for the measurements of the body dimensions after a month of the experiment, laurel oil, clove oil and sage oil had a significant effect on the chest circumference, the width of the body at the front, the width of the body at the back and BCS, and also the parameters had a significant effect on the measurements of body dimensions At the end of the experiment, the characteristics of the height of the body at the front, the height of the body at the back, the circumference of the chest, and the length of the body. As for the characteristics of the wool, the oils used led to a decrease in the percentage of clean wool and an increase in the length of the fiber compared to the control.

Seasonal Variation of Antioxidant Capacity, Phenols, Minerals and Essential Oil Components of Sage, Spearmint and Sideritis Plants Grown at Different Altitudes

Medicinal and aromatic plants are well appreciated for their antioxidant and biocidal activities, while great variation on these activities can be related to the species, environmental conditions and harvesting period. In the present study, the seasonal variation of the antioxidant activity, mineral content, yield and chemical composition of the essential oils (EOs) of sage (Salvia officinalis L.), sideritis (Sideritis perfoliata L. subsp. perfoliata) and spearmint (Mentha spicata L.) were tested under two different environmental conditions, each with a different altitude (namely mountainous and plain). Season affected total phenolic content and antioxidant capacity with increased values during winter and lower values during summer period. In summer, plants accumulated more Fe and had higher EO yield, while P and Na were accumulated more in winter. Altitude had a lesser effect on antioxidant capacity of the plants; however, increased minerals (N, K, Na and Ca) accumulation was found in plain areas. Sage plants had the highest antioxidant capacity, Zn content and EO yield. Sideritis had increased Fe content and spearmint plants revealed high N, Na and Mg levels. Furthermore, altitude and season had an impact on the content of main EOs components in all species. FRAP and ABTS were variably correlated with total phenols and minerals, depending on the species, season and altitude. In few cases, antioxidant activity was found to be inversely linked to some EO components (e.g., α-thujone in sage). Finally, the antioxidant content, minerals and EO yield and composition of the examined MAPs were all altered by season and altitude. These findings can be utilized to implement sage, sideritis and spearmint farming in specific ecosystems, determining the season and areas for harvesting the plants, in order to produce high-value products.

Chemical Composition, Antioxidant and Anti-Inflammatory Activities of Clary Sage and Coriander Essential Oils Produced on Polluted and Amended Soils-Phytomanagement Approach.

The potential of essential oils (EO), distilled from two aromatic plants—clary sage (Salvia sclarea L.) and coriander (Coriandrum sativum L.)—in view of applications as natural therapeutic agents was evaluated in vitro. These two were cultivated on a trace element (TE)-polluted soil, as part of a phytomanagement approach, with the addition of a mycorrhizal inoculant, evaluated for its contribution regarding plant establishment, growth, and biomass production. The evaluation of EO as an antioxidant and anti-inflammatory, with considerations regarding the potential influence of the TE-pollution and of the mycorrhizal inoculation on the EO chemical compositions, were the key focuses. Besides, to overcome EO bioavailability and target accession issues, the encapsulation of EO in β-cyclodextrin (β-CD) was also assessed. Firstly, clary sage EO was characterized by high proportions of linalyl acetate (51–63%) and linalool (10–17%), coriander seeds EO by a high proportion of linalool (75–83%) and lesser relative amounts of γ-terpinene (6–9%) and α-pinene (3–5%) and coriander aerial parts EO by 2-decenal (38–51%) and linalool (22–39%). EO chemical compositions were unaffected by both soil pollution and mycorrhizal inoculation. Of the three tested EO, the one from aerial parts of coriander displayed the most significant biological effects, especially regarding anti-inflammatory potential. Furthermore, all tested EO exerted promising antioxidant effects (IC50 values ranging from 9 to 38 g L−1). However, EO encapsulation in β-CD did not show a significant improvement of EO biological properties in these experimental conditions. These findings suggest that marginal lands polluted by TE could be used for the production of EO displaying faithful chemical compositions and valuable biological activities, with a non-food perspective.

Essential Oils of Sage, Rosemary, and Bay Laurel Inhibit the Life Stages of Oomycete Pathogens Important in Aquaculture.

Saprolegnia parasitica, the causative agent of saprolegniosis in fish, and Aphanomyces astaci, the causative agent of crayfish plague, are oomycete pathogens that cause economic losses in aquaculture. Since toxic chemicals are currently used to control them, we aimed to investigate their inhibition by essential oils of sage, rosemary, and bay laurel as environmentally acceptable alternatives. Gas Chromatography–Mass Spectrometry (GC–MS) analysis showed that the essential oils tested were rich in bioactive volatiles, mainly monoterpenes. Mycelium and zoospores of A. astaci were more sensitive compared to those of S. parasitica, where only sage essential oil completely inhibited mycelial growth. EC50 values (i.e., concentrations of samples at which the growth was inhibited by 50%) for mycelial growth determined by the radial growth inhibition assay were 0.031–0.098 µL/mL for A. astaci and 0.040 µL/mL for S. parasitica. EC50 values determined by the zoospore germination inhibition assay were 0.007–0.049 µL/mL for A. astaci and 0.012–0.063 µL/mL for S. parasitica. The observed inhibition, most pronounced for sage essential oil, could be partly due to dominant constituents of the essential oils, such as camphor, but more likely resulted from a synergistic effect of multiple compounds. Our results may serve as a basis for in vivo experiments and the development of environmentally friendly methods to control oomycete pathogens in aquaculture.

Antibacterial effect of Satureja hortensis and Salvia officinalis essential oils against major bovine mastitis bacteria

Treatment of bacterial diseases such as bovine mastitis with antibiotics has problems such as antibiotic resistance and drug residue in animal products. Essential oil of medicinal plants have antibacterial activity and are suitable alternatives. This study examined the antimicrobial activity of Salvia officinalis (sage) and Satureja hortensis (savory) essential oils on major mastitis-causing bacteria, including Staphylococcus aureus, Streptococcus agalactiae, and Escherichia coli. Chemical compositions of essential oils were determined by gas chromatography-mass spectrometry. Minimum inhibitory concentration and minimum bactericidal concentration of oils were determined with serial broth dilution method using autoclaved whole milk rather than synthetic broth. The effect of sub-minimum inhibitory concentrations of essential oils on the growth curve of tested bacteria in milk was obtained in 0, 1, 2, 4, 10, and 24 hours. Major compositions of sage and savory essential oils were carvacrol (61.01%), thymol (20.41%), 1R-α-pinene (7.88%), eucalyptol (32.45%), thymol (28.24%), and α-pinene (13.42%), respectively. The minimum inhibitory concentration and minimum bactericidal concentration ranged 1.25-2.5% and 2.5-5% for savory, and 0.625-1.25% and 1.25-2.5% for sage, respectively. Savory and sage significantly decreased the S. aureus and S. agalactiae population in 4, 10, and 24 h (p < 0.05) and E. coli population in 10 and 24 h (p = 0.01). The sage and savory essential oils had antibacterial effects against three tested bacteria, and sage had a stronger effect than savory because of stronger antibacterial components (carvacrol and thymol). Further in vivo tests are recommended to evaluate the efficiency of these essential oils on the treatment of bovine mastitis.

Biological activity and chemical characteristics of essential oils from the indigenous plant in Palestine

New pesticides based on plant extracts and essential oils (EO) are the modern approach to control insect pests and diseases and replacing synthetic pesticides. Therefore, a preliminary screening of nine indigenous plants containing essential oil for antifungal and insecticidal impacts on selected microorganisms and insect pests was evaluated during 2018-19 at Kadoorie Agricultural Research Center (KARC), Palestine Technical University. The biological properties of the plant extracts and EO were tested in vitro. Results showed that clove, thyme and eucalyptus oil significantly inhibited the growth of A. niger, B. cinerea, A. flavus, P. ultimum, P. digitatum and F. oxysporum 24 and 48 hr post-application. EC50 and EC90 values were significantly the lowest for eucalyptus, thyme then clove. LC50 and LC90 values against green peach aphid and two-spotted red spider mite were calculated from log-dose probit mortality regression. EO bioassay on aphid showed no significant impact of aphid mortality among all the EO, but a significant effect on the two-spotted red spider mites mortality. Mustard, sage and bitter-cucumber oil applications have high mortality on aphid, while mustard, mint and sesame oil application have high mortality on the two-spotted red spider mite. EO showed no significant impact on plant enzyme activities as in expression values of PPO and POX. The biological activity of the EO investigated on several microorganisms, and insect pests suggested that clove, eucalyptus and thyme showed the highest antifungal activities, while mint, mustard and sesame have the highest insecticidal and acaricidal activities.