Sativa Essential Oil Research Articles

Inhibition of Bacillus cereus by garlic (Allium sativum) essential oil during manufacture of white sufu, a traditional Chinese fermented soybean curd

This study aimed to apply garlic essential oil (GEO) to control the Bacillus cereus content in white sufu, a traditional Chinese fermented soybean curd. The effect of GEO on the Bacillus cereus count, bacterial composition, and the metabolic changes during the fermentation process were investigated. After treatment with GEO, B. cereus was reduced from 5.26 to 4.58 log CFU/g in the finished product, meeting the Hong Kong Food Microbiological Guidelines. Three Lactic acid bacteria genera (Lactococcus, Weissella, and Leuconostoc), which showed a positive correlation with desirable metabolites, were present in greater numbers after the treatment. Hierarchical cluster analysis and principal component analysis showed that GEO caused no significant differences in polar metabolites (carbohydrates, organic acids, biogenic amines, nitrogen compounds, and free amino acids) and volatile compounds in the end-product. Thus, GEO appears to have great potential in sufu manufacture and preservation.

LARVICIDAL EFFICACY OF NIGELLA SATIVA SEEDS OIL AND IT’S NANOPARTICLES AGAINST CULEX PIPIENS AND MUSCA DOMESTICA

Extensive and continuous use of synthetic chemical insecticides led to environmental hazards to non-target organisms, and development of insect’s resistance. The present study evaluated essential oil of Nigella sativa seeds as a friendly larvicidal measure for Culex pipiens and Musca domestica vectors of infectious diseases. The N. sativa components essential oil was analyzed by GC-MS. Sixteen components were identified. The selenium nanoparticles (SeNPs)with N. sativa essential oil were prepared to form N. sativa SeNPs and proved by UV-Spectrophotometer, FT-IR, and SEM. The droplet size of nanoemulsion was 65±11.4 nm. The bioassay showed that N. sativa essential oil and its nanoparticles were more effective against larvae of Cx. pipiens than those of M. domestica.

Antibacterial Effect of Some Palestinian Plant Extracts against Clinical Multidrug-Resistant Gram- Negative Bacteria: A possible synergism with antibiotics

Objectives: The present study was designed to screen the antibacterial and synergistic effects of Allium sativum, Ecballiumelaterium, Pelargoniumgraveolens, Rosmarinusofficinalis, Phagnalonrupestre and Rutagraveolens plant extracts and essential oils against the followingclinical multidrug-resistant(MDR) Gram negative pathogenic isolates: Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.
 Methods: All extracts and essential oils were screened for their antibacterial activity and synergistic effect in combination with known antibiotics.The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the plant extracts were assessed.
 Results: Our results revealed that, the average diameter of inhibition zones ranged from: 7-14 mm, 7-17 mm, 8-17 mm and 7-13 mm for water, ethanol, methanol and EOs extracts, respectively. The MICs and MBCs were determined for extracts which showed antibacterial activity. The average MICs values ranged from 1.6-100 mg/ml, 1.6-50 mg/ml, 0.39 -50 mg/ml and 3.13-100 μl/ml for water, ethanol, methanol and EOs extracts, respectively. While MBCs values ranged from 25->200 mg/ml, 25- 200 mg/ml and 50->200 μl/ml for water, ethanol, methanol and EOs extracts, respectively. The antibacterial activity of the afore mentioned plant extracts combined with Ciprofloxacin (CIP), Ampicillin (AM), Cefotaxime (CTX), Nalidixic acid (NA), Norofloxacin (NOR), Cefuroxime (CXM), Cefaclor (CF), Ofloxacin (OFX), Cefalexin (CL), Tetracycline (TE), Rifampicin (RIF), Amoxyclav (AMC) and Amikacin (AK) had different degrees of synergism against the selectedbacteria.Essential oils (Eos) of screened plants had the best synergism with antibiotics than the plant extracts against the tested bacteria. The best synergism was noticed in the Eos of A. sativum, P. graveolens and R. officinalis.
 Conclusion: It was concluded that the synergistic effect of antibiotics and plant extracts is promising approach fortreating infectious diseases caused byMDR Gram negative bacteria.
 Bangladesh Journal of Medical Science Vol.19(3) 2020 p.509-519

Antioxidant, Antimicrobial and Antibiofilm Activity of Coriander (Coriandrum sativum L.) Essential Oil for Its Application in Foods

The aim of this study was to assess the chemical composition, antioxidant, antimicrobial and antibiofilm activity of the Coriandrum sativum essential oil. Changes in the biofilm profile of Stenotropomonas maltophilia and Bacillus subtilis were studied using MALDI-TOF MS Biotyper on glass and wooden surfaces. The molecular differences of biofilms in different days were observed as well. The major volatile compounds of the coriander essential oil in the present study were β-linalool 66.07%. Coriander essential oil radical scavenging activity was 51.05% of inhibition. Coriander essential oil expressed the strongest antibacterial activity against B. subtilis followed by S. maltophilia and Penicillium expansum. The strongest antibiofilm activity of the coriander essential oil was found against S. maltophilia. A clearly differentiated branch was obtained for early growth variants of S. maltophilia in case of planktonic cells and all experimental groups and time span can be reported for the grouping pattern of B. subtilis preferentially when comparing to the media matrix, but without clear differences among variants. The results indicate that coriander was effective against the tested Penicillium expansum in the vapor phase after 14 days with MID50 367.19 and MID90 445.92 µL/L of air.

Anti-parasitic Activity of Some Medicinal Plants Essential Oils on Giardia lamblia and Entamoeba histolytica, In Vitro

Background and objectives: Giardiasis and amoebiasis are two common diseases in human societies which make increasing problems for the health managing systems. In the present study, the antiparasitic activity of Allium sativum, Artemisia sieberi, Zatraria multiflora, Chenopodium botrys and Eucalyptus globulus essential oils on Giardia lamblia cysts and Entamoeba histolytica trophozoites were investigated in vitro. Methods: Giardia lamblia cysts and E. histolytica trophozoites were isolated from infected sample stools. The parasites were treated by four concentrations (0.2, 0.1, 0.01 and 0.001 µg/mL) of essential oils, separately for 30 min at 37 °C. Results: Theessential oils at the concentration of 0.1 and 0.2 µg/mL indicated appreciate parasiticidal effect (p <0.05). Eucalyptus globulus had maximum efficacy on both G. lamblia and E. histolytica with mortality rates of 79.7% and 87.6% within 30 min. Conclusion: All essential oils showed potent anti-giardiasis and anti-amoebiasis activity. Also, E. globulus with the highest efficiency could be considered as anti-protozoa medication to use an adjunct or primary therapy.

GC-MS Analysis of Commercially Available Allium sativum and Trigonella foenum-graecum Essential Oils and their Antimicrobial Activities

GC-MS Analysis of Commercially Available Allium sativum and Trigonella foenum-graecum Essential Oils and their Antimicrobial Activities

Bioactive Compounds of Nigella Sativa Essential Oil as Antibacterial Agents against Chlamydia Trachomatis D.

Urogenital tract infection caused by obligate intracellular bacterium Chlamydia trachomatis D (CtrD) is a leading cause of sexually transmitted diseases. Essential oil (EO) of Nigella sativa has a broad antimicrobial spectrum. The aim of this study was to evaluate the antimicrobial activity of the bioactive compounds (p-cymene, thymoquinone, carvacrol, and thymol) of N. sativa EO against CtrD. The cytotoxic effects of the compounds were determined by MTT assay. In order to quantify the anti-chlamydial activity of the compounds, HeLa cells were infected with CtrD or CtrD treated previously with the compounds. The titer of the infectious CtrD was determined by indirect immunofluorescence assay. The minimum inhibitory concentrations of the compounds were evaluated by direct quantitative PCR. None of the compounds showed a cytotoxic effect on HeLa cells in the concentrations tested. According to the immunofluorescence assay, all of the compounds significantly inhibited the growth of CtrD. The quantitative PCR revealed that the minimum concentration that exerted anti-chlamydial activity was 3.12 µM in the case of thymoquinone and p-cymene, while that of carvacrol and thymol was 6.25 µM. Therefore, it can be concluded that bioactive compounds of N. sativa EO could be used as effective antimicrobial agents against CtrD.

Application of Optimization Technique to Develop Nano-Based Carrier of Nigella Sativa Essential Oil: Characterization and Assessment.

: BackgroundChitosan, a naturally occurring polymer, has interesting applications in the field of drug delivery due to its plentiful advantages as biodegradability, biocompatibility and nontoxic nature. Nigella sativa essential oil is unstable, volatile, and insoluble in water and these problems confine its usage in developing new medicines.ObjectiveThis study focuses on developing a chitosan-based nanocarrier for the encapsulation of Nigella Sativa essential oil. By using Quality by design outline, the quality target product outline, critical quality attributes and critical material attributes were defined by knowledge and risk-based procedures.MethodsAccording to defined critical material attributes, Optimization software (Statgraphics XVII) was used to study the effect of the processing parameters. The processing parameters identified and fixed first with a “One factor at a time” approach. Various physicochemical characterization techniques were performed.ResultsAs a result, the ratio of chitosan to benzoic acid (2:1) along with the stirring rate (4000 rpm) produced minimum-sized particles (341 nm) with good stability. The anti-bacterial activity study using Staph. Aureus strain proved that the optimized nanoparticles were more efficacious than the pure oil based on the diameter of inhibition zone obtained (diameter =5.5 cm for optimized formula vs diameter = 3.6 cm for pure oil). Furthermore, MTT (methyl thiazolyl-diphenyl-tetrazolium bromide) assay was performed to compare the in vitro cytotoxicity using two different cell lines (i.e. HCT 116 for colorectal carcinoma and PC3 for prostatic cancer). It was found that in both cell lines, the optimized nanoparticles had noteworthy antiproliferative properties illustrated by determining the concentration at which 50% of growth is inhibited (IC50). The optimized nanoparticles showed lower IC50 (17.95 ±0.82 and 4.02 ±0.12μg/ml) than the bare oil IC50 (43.56 ±1.95 and 29.72 ±1.41μg/ml).

Alpha-Hederin, the Active Saponin of Nigella sativa, as an Anticancer Agent Inducing Apoptosis in the SKOV-3 Cell Line.

Alpha-hederin (α-HN), a pentacyclic triterpene saponin, has recently been identified as one of the active compounds of Nigella sativa, as a potential anticancer agent. However, no extensive studies on α-HN have been done as yet, as it was in the case of thymoquinone—the main ingredient of the N. sativa essential oil. To our knowledge, there are also no data available on how α-HN acts on the human cancer ovarian cell line SKOV-3. In this study we attempt to present the cytotoxic influence of α-HN on the SKOV-3 cell line by means of two methods: Real-Time xCELLigence and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The obtained IC50 values are 2.62 ± 0.04 μg/mL and 2.48 ± 0.32 μg/mL, respectively. An induction of apoptosis in SKOV-3 cells was confirmed by staining cellular nuclei with Hoechst 33342 dye and by flow cytometry analysis by binding annexin V to the cell membranes. We found that α-HN induces apoptosis in a dose-dependent manner. In the first stages of apoptosis, the mitochondrial membrane potential was found to decrease. Also, inactivation of anti-apoptotic protein Bcl-2 was observed, as well as the caspase-9 and then caspase-3/7 activation. In addition, the treatment of SKOV-3 cells with α-HN induced the cell cycle arrest of cancer cells in G0/G1 phase. The results of our investigations indicate that α-HN induces apoptosis in the SKOV-3 cell line and that the intrinsic mitochondrial pathway is involved in the programmed cancer cell death.

Exploring Ecological Alternatives for Crop Protection Using Coriandrum sativum Essential Oil.

Essential oils (EOs) are a natural source of active compounds with antifungal, antimycotoxigenic, and herbicidal potential, and have been successfully used in organic agriculture, instead of chemical compounds obtained by synthesis, due to their high bioactivity and the absence of toxicity. The aim of this study was to highlight the importance of Coriandrum sativum essential oil (CEO) as a potential source of bioactive constituents and its applications as an antifungal and bioherbicidal agent. The CEO was obtained by steam distillation of coriander seeds and GC-MS technique was used to determine the chemical composition. Furthermore, in vitro tests were used to determine the antifungal potential of CEO on Fusarium graminearum mycelia growth through poisoned food technique, resulting in the minimum fungistatic (MCFs) and fungicidal concentrations (MCFg). The antifungal and antimycotoxigenic effect of CEO was studied on artificially contaminated wheat seeds with F. graminearum spores. Additionally, the herbicidal potential of CEO was studied by fumigating monocotyledonous and dicotyledonous weed seeds, which are problematic in agricultural field crops in Romania. The in vitro studies showed the antifungal potential of CEO, with a minimum concentration for a fungistatic effect of 0.4% and the minimum fungicidal concentration of 0.6%, respectively. An increase in the antifungal effects was observed in the in vivo experiment with F. graminearum, where a mixture of CEO with Satureja hortensis essential oil (SEO) was used. This increase is attributed to the synergistic effect of both EOs. Moreover, the synthesis of deoxynivalenol (DON)-type mycotoxins was found to be less inhibited. Hence, CEO has shown an herbicidal potential on weed seeds by affecting inhibition of germination.

Antioxidant activity and evidence for synergism of Cannabis sativa (L.) essential oil with antimicrobial standards

The present work was conducted to study the antioxidant activity and to determine for the first time the antimicrobial potential of Moroccan Cannabis sativa essential oil (EO) singly or in combination with two conventional antibiotics (fluconazol and ciprofloxacin) against some resistant and pathogenic microorganisms. The chemical composition analyzed by means of GC/MS showed that C. sativa EO was characterized by the dominance of (E)-caryophyllene (35.0%), α-humulene (12.8%) and caryophyllene oxide (10.6%). Results from antioxidant tests showed that C. sativa EO exhibit a moderate potency (IC50 = 1.6 ± 0.1 mg/m L for 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay, IC50 = 1.8 ± 0.2 mg/mL for β-carotene/linoleic acid assay, and IC50 = 0.9 ± 0.1 mg/m L for ferric reducing power assay). Regarding antimicrobial assays, the results demonstrated that C. sativa EO displayed interesting antimicrobial activities with minimum inhibitory concentration (MIC) values in the range from (1.2 to 37.8) mg/m L for tested microorganisms. The combination of the studied EO with fluconazol and ciprofloxacin showed a significant decrease in their individual MICs. In fact, at sub-inhibitory concentrations, C. sativa EO contributed to the decrease of ciprofloxacin MICs of bacterial strains by 2- to 64-fold and by16-fold regarding fluconazol MICs against Candida spp. These findings suggest that C. sativa EO can be considered as a potential source of natural antioxidant and antimicrobials, and constitute in combinational treatments a promising strategy to overcome the intense use of antibiotics against some infectious diseases.

Encapsulation in chitosan-based nanomatrix as an efficient green technology to boost the antimicrobial, antioxidant and in situ efficacy of Coriandrum sativum essential oil

The present investigation deals with first time report on encapsulation of Coriandrum sativum essential oil (CSEO) in chitosan nanomatrix as a green nanotechnology for enhancing its antimicrobial, aflatoxin inhibitory and antioxidant efficacy. Chitosan nano biopolymer entrapped CSEO as prepared through ionic gelation process showed broad spectrum fungitoxicity against molds infesting stored rice and also exhibited enhanced bioefficacy than unencapsulated CSEO. The CSEO entrapped in chitosan nanomatrix lead to decrement in important fungal membrane biomolecule i.e. ergosterol and leakage of UV-absorbing substances along with vital cellular ions. The CSEO encapsulation in selected biopolymer nanomatrix effectively checked methylglyoxal (the aflatoxin inducer) biosynthesis, confirming antiaflatoxigenic mode of action. The physico-chemical properties, considerable decrease in lipid peroxidation and improved in situ AFB1 suppressive as well as antifungal potential of CSEO nanocapsules suggested the deployment of chitosan based nano biopolymer for encapsulation of essential oils as an ecofriendly technology for application in food industries in order to enhance the shelf life and control the fungal and aflatoxin contamination of stored rice.

Single Clove Garlic (Allium sativum) Essential Oil as an Inhibitor of Staphylococcus aureus Bacteria

Staphylococcus aureus is gram-positive bacteria that often infect the skin. S. aureus has been experiencing resistance to several antibiotics. One of the solutions to overcome the resistance is by using garlic that is believed by the society can overcome bacterial infection. The study aimed to find out the influence of the variation in concentration of local single clove garlic essential oil used on the inhibition and damage of morphological structure of S. aureus bacteria. The inhibition test was conducted using disc diffusion method. The experiment groups consisted of 1% DMSO as negative control, vancomycin 30µg/ml as positive control and single clove garlic essential oil (25 mg/ml, 50 mg/ml, 75 mg/ml and100 mg/ml) as treatment groups. The diameter of inhibition zone was measured using calipers. The morphological damage of the bacterial cells can be seen using Scanning Electron Microscopy (SEM) with magnification of 25000x. The result of Kruskal-Wallis test analysis indicated that the extract of local garlic essential oil has inhibitory activities against S. aureus bacteria (P&lt;0.05). The damage to the morphological structure of bacterial cells with the administration of 30 µg/ml vancomycin was equal to 100 mg/ml single clove garlic essential oil extract. Single clove garlic essential oil can be used as an alternative treatment for skin infection diseases by inhibiting S. aureus growth.

Antifungal and antiaflatoxinogenic activities of Carum carvi L., Coriandrum sativum L. seed essential oils and their major terpene component against Aspergillus flavus

With the purpose of searching for biological substances for controlling aflatoxins production in foodstuffs, we assessed the antifungal and antiaflatoxigenic activities of two essential oils (EOs) extracted from Carum carvi L., Coriandrum sativum L. seed and their major terpene component against Aspergillus flavus. The chemical profiles of Carum carvi, and Coriandrum sativum EOs were identified through Gas chromatography mass spectrometry analysis where carvone and linalool were respectively, recorded as the major terpene compound (78.85 and 72.34%). The effects of the EOs (0.1–0.7% (v/v)) and terpenes (100–2000 μg/mL) on the hyphal extension and aflatoxin B1 (AFB1) synthesis of A. flavus were tested by contact assay in Yeast Extract Sucrose medium. Carum carvi EO displayed a higher antimicrobial activity against A. favus than Coriandrum sativum EO with a minimum inhibitory concentration of about 0.4 and 0.7%, respectively. In the presence of 0.3% of EOs, 73.3 and 99.6% inhibition of AFB1 production was recorded, respectively, with Coriandrum sativm and Carum carvi. The antifungal and antiaflatoxigenic effects of carvone were also more significant than those of linalool (p < 0.05) with respectively, 64 and 16% of growth rate inhibition and 77.9 and 0.1% of AFB1 synthesis decrease recorded at 1000 μg/mL. Hence, the antifungal and antiaflatoxigenic activities of the two tested EOs were similar to their main terpene component. In conclusion, seed essential oils proved to be apotential natural source of antifungal and aflatoxin inhibition agent against Aspergillus flavus.

Nigella sativa essential oil and its bioactive compounds as resistance modifiers against Staphylococcus aureus.

Nigella sativa essential oil (EO) and its compounds (thymoquinone, carvacrol, and p-cymene) have a broad antimicrobial spectrum. The aim of this study was to investigate the antimicrobial and resistance modifying activity of N.sativa EO, thymoquinone, carvacrol, and p-cymene against one methicillin susceptible and one methicillin resistant Staphylococcus aureus strain. N.sativa EO, thymoquinone, carvacrol, and p-cymene were assessed for antimicrobial activity and modulation of antimicrobial resistance (by broth microdilution), inhibition of antimicrobial efflux (by ethidium bromide [EtBr] accumulation assay), relative expression of mepA gene (by real-time reverse transcriptase quantitative polymerase chain reaction), membrane disrupting effect (by LIVE/DEAD BacLight™ Kit), and finally antibiofilm activity (by the crystal violet assay). Both strains of S.aureus were susceptible to N.sativa EO, thymoquinone, and carvacrol. N.sativa EO and carvacrol induced the increase of EtBr accumulated by both S.aureus strains. Membrane integrity of ATCC strain was disrupted by carvacrol and p-cymene, whereas for the methicillin resistant S.aureus (MRSA) strain the membrane integrity was disrupted by each compound. N.sativa EO and its bioactive compounds such as carvacrol and p-cymene could be applied as resistance modifiers in MRSA strains.

Bio-efficacy and physiological effects of Eucalyptus globulus and Allium sativum essential oils against Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Toxicity Allium sativum and Eucalyptus globulus essential oils were investigated against Ephestia kuehniella larvae in addition to physiological effects on digestive enzymes, intermediary metabolism, antioxidant response and storage macromolecules. The LC50s of 2.801 and 6.111 µl/ml were recorded for A. sativum- and E. globulus EOs as the highest concentrations caused 83.3% and 80% of larval mortality. The lowest activities of α-amylase, TAG-lipase, and carboxypeptidase were recorded in the larvae treated by A. sativum EO, while the larvae treated by E. globulus EO showed the lowest activities of trypsin, chymotrypsin, and aminopeptidase. The activities of elastase and glucosidases decreased in the treated larvae but no significant differences were recorded between EOs. Activities of esterase and glutathione S-transferase significantly increased in the larvae treated by EOs similar to aminotransferases while the activities of lactate dehydrogenase, acid- and alkaline phosphatases significantly decreased in the EO-treated larvae. The higher activities of ascorbate peroxidase, glycerol-6-phosphate dehydrogenase, malondialdehyde, and ratio of RSSR/RSH were found in the EO-treated larvae while superoxide dismutase, peroxidase, and catalase had the highest activities in EgEO-treated larvae. Both EOs significantly decreased the activity of acetylcholine esterase and the amounts of storage macromolecules, protein, glycogen, and triglyceride.

Identification of attractants from plant essential oils for Cyrtorhinus lividipennis, an important predator of rice planthoppers

The brown planthopper (BPH), Nilaparvata lugens, is a serious insect pest in rice cultivation, while Cyrtorhinus lividipennis, its main predator, feeds on BPH eggs and nymphs. The artificial release of C. lividipennis could significantly suppress the increase in BPH and prevent hopper burn in the open field. How to attract the artificially released C. lividipennis to the precise location of the target rice field is key for successful biological control. However, there have been few reports related to C. lividipennis. In the current study, we identified two attractant compounds for C. lividipennis from plant essential oils. Using olfactometer assays, we found that Coriandrum sativum and Nerium indicum essential oils were highly attractant to both adults and nymphs of C. lividipennis. The petroleum ether fractions of C. sativum, N. indicum, and Alpinia officinarum essential oils were analyzed with GC-MS. According to previous reports and the results of the GC-MS analysis, we selected ten compounds to screen their attractancy to C. lividipennis. After the olfactometer assays, we identified isocaryophyllene and trans-2-dodecenol, which were the most effective attractants to C. lividipennis under laboratory conditions. Our experiments under greenhouse and field conditions showed that isocaryophyllene and trans-2-dodecenol presented significant attractancy to C. lividipennis. These results highlight the potential of isocaryophyllene and trans-2-dodecenol as effective attractants to aid C. lividipennis in locating target rice fields during their artificial release. Further studies are required to develop a formulation that would increase efficacy with lower costs.

Antifungal Activity of Garlic (Allium sativum) Essential Oil and Wood Ash against Post-harvest Fruit Rot of Banana (Musa acuminata L.) in Yola, Adamawa State, Nigeria

Studies on antifungal effect of garlic (Allium sativum) essential oil and wood ash were determined on causative agents of post-harvest fruit rot of banana. Different concentrations of essential oil of garlic (0.15, 0.50, and 1.0%) and quantities of wood ash (0.1, 0.3 and 0.5g) were used. The treatments were laid out in Completely Randomized Design (CRD) with three replications. Four (4) fungal pathogens associated with rots of banana fruits were isolated. The fungi isolated and their incidence of occurrence included Colletotrichum musae (18%), Pyricularia grisea (18%), Rhizoctonia solani (38%) and Rhizopus stolonifer(26%). Rhizoctonia solani and Rhizopus stolonifer were the most pathogenic with rot covering more than 75% of the fruit surface. All the tested concentrations (0.15, 0.5 and 1.0%) of essential oil of garlic significantly (p < 0.05) suppressed mycelial growth of the fungi in-vitro. Also all tested quantities of wood ash (0.1, 0.3 and 0.5g) significantly (p < 0.05) reduced the rots of the fungi in-vivo. The effect was proportional to the concentrations of essential oil of garlic and quantities of wood ash used and reduction was highest at 1.0% of garlic oil and 0.5g of wood ash. Both garlic (Allium sativum) essential oil and wood ash proved effective in the control of disease severity and these natural plant materials are recommended as an alternative to pesticides which are often harmful and costly.

Chemical Characterization and Antibacterial Activity of the Essential Oil of Coriandrum sativum Leaves in the West of Iran (Kermanshah)

Medicinal plants are recommended for prevention, control and treatment of different diseases. Due to the rapid growth of global interest in the use of medicinal plants, their effects and safety assessment have become highly important. In this study, Coriandrum sativum was extracted to investigate its chemical composition and antibacterial effect against Escherichia coli O157:H7, Pseudomonas aeruginosa, Listeria monocytogenes, Salmonella typhimurium, Proteus mirabilis, Staphylococcus aureus, Staphylococcus saprophyticus, Streptococcus pneumonia, Bacillus subtilis and Enterococcus faecalis. Gas Chromatography Mass Spectrometry (GC/MS) was done to determine the chemical composition of C. sativum essential oil. Agar disk and agar well diffusion methods were used to investigate the antibacterial activity of the essential oil. Macrobroth tube test was run to specify Minimum Inhibitory Concentration (MIC). The results indicated that linalool (66.8%) was the most frequently found constituents in C. sativum. The bacterial data revealed that inhibition zone in all bacteria increased when the concentration of C. sativum was increased (p<0.01). Also, C. sativum with 2-8 mg/mL concentrations prevented the growth of ten selected bacteria, and with 2-16 mg/mL concentrations removed them. The results showed the antibacterial property of C. sativum. It appears that this plant can be used as an antibiotic to treat some bacterial infections. Fractionation of active molecules is suggested to be perused in the future studies.

Attenuation of Listeria monocytogenes Virulence by Cannabis sativa L. Essential Oil.

Anti-virulence strategies are being explored as a novel approach to combat pathogens. Such strategies include inhibition of surface adhesion, tissue invasion, toxin production, and/or interference with the gene regulation of other virulence traits. Listeria monocytogenes, the causative agent of listeriosis, is a facultative intracellular food pathogen characterized by a wide distribution in the environment. Its ability to persist within biofilms and to develop resistance to sanitizers is the cause of significant problems in food processing plants and of steep costs for the food industry. In humans, the treatment of listeriosis is hampered by the intracellular location of listeriae and the poor intracellular penetration of some antibiotics. Eleven L. monocytogenes isolates from patients who were diagnosed with invasive listeriosis in Italy in 2014–2016 were studied. This in vitro and in vivo study explored the antibacterial and anti-virulence properties of a steam-distilled essential oil of Cannabis sativa L., which is being intensively investigated for its high content in powerful bioactive phytochemicals. Susceptibility experiments demonstrated a moderate bactericidal activity of the essential oil (Minimum Bactericidal Concentration > 2048 μg/mL). Assessment of the effects of sublethal concentrations of the essential oil on L. monocytogenes virulence traits demonstrated a significant action on motility. Listeriae were non-motile after exposure to the essential oil. Light and scanning electron microscopy documented aggregates of listeriae with the flagella trapped inside the cluster. Real-time RT-PCR experiments showed downregulation of flagellar motility genes and of the regulatory gene prfA. The ability to form biofilm and to invade Caco-2 cells was also significantly reduced. Galleria mellonella larvae infected with L. monocytogenes grown in presence of sublethal concentrations of the essential oil showed much higher survival rates compared with controls, suggesting that the extract inhibited tissue invasion. Food contamination with L. monocytogenes is a major concern for the food industry, particularly for plants making ready-to-eat and processed food. The present work provides a baseline in the study of the anti-virulence properties of the C. sativa essential oil against L. monocytogenes. Further studies are needed to understand if it could be used as an alternative agent for the control of L. monocytogenes in food processing plants.