Composition of garlic essential oil (Allium sativumL.) as influenced by drying method

Potential fumigant toxicity of essential oils against Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) and its egg parasitoid Trichogramma evanescens (Hymenoptera: Trichogrammatidae)

Sitotroga cerealella is a serious pest of a wide range of stored cereal grains. An essential element of an integrated pest control approach is the application of plant oils as a substitute for chemical insecticides. This study aimed to investigate the fumigant toxicity of Allium sativum and Mentha piperita essential oils against S. cerealella adult moths and the egg parasitoid Trichogramma evanescens. Gas chromatography-mass spectrometry analyses detected that Diallyl trisulfide (37.97%) and DL-Menthol (47.67%) as main compounds in A. sativum and M. piperita, respectively. The results showed that, A. sativum at 10.0, 5.0, and 2.5 µL/L air resulted in 100% insect mortality after 24 h exposure. The concentrations of 10.0 and 5.0 µL/L air of M. piperita oil resulted in 100 and 96% insect mortality, respectively. The parasitoid adult emergence in the F1 reduced when exposed to LC99 of A. sativum and M. piperita oils by 10.89 and 9.67%, respectively. Also, the parasitism of emerged parasitoid decreased by 9.25 and 5.84% (class I-harmless), respectively. Therefore A. sativum and M. piperita have the potential to be used as bio-fumigant for the management of S. cerealella and can be used alongside the T. evanescens in integrated pest management.

Electrospun nanofibers based on zein and red onion bulb extract (Allium cepa, L.): Volatile compounds, hydrophilicity, and antioxidant activity

Onion is rich in bioactive and volatile compounds with antioxidant activity. However, the pungent odor of volatile compounds (VOCs) released restricts its use. The encapsulation of red onion extract by electrospinning is an alternative to mask this odor and protect its bioactive compounds. The main objective of this study was to encapsulate red onion bulb extract (ROE) in different concentrations into zein nanofibers by electrospinning and evaluate their thermal, antioxidant, and hydrophilicity properties. The major VOC in ROE was 3(2H)-furanone, 2-hexyl-5-methyl. Incorporating ROE into the polymeric solutions increased electrical conductivity and decreased apparent viscosity, rendering nanofibers with a lower average diameter. The loading capacity of ROE on fibers was high, reaching 91.5% (10% ROE). The morphology of the nanofibers was random and continuous; however, it showed beads at the highest ROE concentration (40%). The addition of ROE to the nanofibers increased their hydrophilicity. The nanofibers' antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl, nitric oxide, and hydroxyl radicals ranged from 32.5% to 57.3%. The electrospun nanofibers have the potential to protect and mask VOCs. In addition, they offer a sustainable alternative to the synthetic antioxidants commonly employed in the food and packaging industry due to their antioxidant activities.

OPTIMIZATION AND CHARACTERIZATION OF ESSENTIAL OILS FORMULATION FOR ENHANCED STABILITY AND DRUG DELIVERY SYSTEM OF MEFLOQUINE

Objective: This work aims to choose suitable essential oil formulations to improve the bioavailability and long-term aqueous stability of mefloquine in drug delivery systems. Methods: Oil phases of pomegranate oil, black cumin seed oil, and garlic oil. To choose the proper oil and surfactant for creating pseudo-ternary phase diagrams, cremophore EL, tween®20 and tween®80 (surfactants), and brij 35 (co-surfactants) were used in a variety of concentrations and combinations (Smix). Mefloquine was estimated to be soluble in a variety of oils, surfactants, and co-surfactants. Drug solubility, drug release research, thermodynamic stability, mean hydrodynamic size and zeta potential. Results: Garlic with smix of cremophore EL and brij 35, Pomegranate with Tween 2.0, and Black cumin seed oil with Tween 80 showed the highest solubilization and emulsification capabilities and were further investigated using ternary phase diagrams. When combined with the co-surfactants under investigation, cremophore EL demonstrated a greater self-emulsification zone than tween® 80 and tween 20. Garlic oil, cremophore EL, and brij 35 nanoemulsion showed smaller size, greater zeta potential, less emulsification time, high transmittance, and better drug solubility than microemulsion formulations on especially those made with tween®20 and tween 80. Mefloquine loaded garlic oil nanoemulsion showed considerably low release in body fluid (32.48%) and a good release in intestinal fluid (82.78%) by 12 h in a drug release study. Conclusion: Garlic oil as the oil phase and a mixture of cremophore EL and brij 35 as the surfactant phase are ideal surfactants and co-surfactant for mefloquine loaded garlic oil nanoemulsion with greater drug release in release kinetics investigation.

Insecticidal Activity of Essential Oils against Mealybug Pests (Hemiptera: Pseudococcidae): A Systematic Review and Meta-Analysis

Most mealybugs of the Pseudococcidae family are important pests of agriculture and ornamental gardens. Our aim was to perform a review and meta-analysis on 14 published scientific articles on the insecticidal activity of essential oils (EOs) against mealybug species of the Pseudococcidae family. Data on (1) species, genus, families, and plant parts from which the EO was extracted; (2) the main compounds of each EO; (3) the highest and lowest concentrations tested; and (4) the application method used for the toxicological studies was collected from each study. The metafor package (R software) was used to perform a three-level random effects meta-analysis. The families Lamiaceae, Rutaceae, Myrtaceae, Zingiberaceae and Euphorbiaceae and the genera Citrus, Cymbopogon, Syzygium, Cinnamomum and Jatropha were the most used among the studies. According to the results from the meta-analyses, 13 out of 24 genera analyzed were effective against mealybugs. All methods were effective, but fumigation and indirect contact were the most frequently used methodologies. The results obtained from the present review and meta-analysis could be used for the potential development of natural biopesticide formulations against mealybugs belonging to the Pseudococcidae family.

Garlic and ginger essential oil-based neomycin nano-emulsions as effective and accelerated treatment for skin wounds' healing and inflammation: In-vivo and in-vitro studies

Skin, largest organ of human, is directly exposed to environment and hence is prone to high rates of injuries and microbial infections. Over the passage of time these microbes have developed resistance to antibiotics making them ineffective especially in lower doses and hence, higher dosages or new drugs are required. The current study deals with designing of nano-emulsion (NE) formulations composed of garlic and ginger oils (0.1 %) with neomycin sulphate used in different ratios (0.001, 0.01 and 0.1 %) and combinations. The resulting NEs were characterized for droplet size (145-304 nm), zetapotential (-3.0-0.9 mV), refractive index (1.331-1.344), viscosity (1.10-1.23cP), transmittance (96-99 %), FT-IR and HPLC and found stable over a period of three months. All NEs were also found effective against both gram positive and negative bacterial strains i.e., B. spizizenii, S. aureus, E. coli and S. enterica as compared to pure neomycin sulphate (NS) used as control with highest activity recorded for NE-2 and NE-4 against all strains showing zone of inhibition in range of 22-30 mm and 21-19 mm, respectively. NEs were also tested using rabbit skin excision wound model which potentiates that all the NEs resulted in early recovery with 86-100 % wound healing achieved in 9 days as compared to NS ointment (71 %). The studies confirmed that essential oils when used in combination with traditional drug can lead to much higher efficacies as compared to pure drugs.

Traditional uses, phytochemistry, pharmacology and toxicology of garlic (Allium sativum), a storehouse of diverse phytochemicals: A review of research from the last decade focusing on health and nutritional implications

Allium sativum L. (Garlic) is a fragrant herb and tuber-derived spice that is one of the most sought-after botanicals, used as a culinary and ethnomedicine for a variety of diseases around the world. An array of pharmacological attributes such as antioxidant, hypoglycemic, anti-inflammatory, antihyperlipidemic, anticancer, antimicrobial, and hepatoprotective activities of this species have been established by previous studies. A. sativum houses many sulfur-containing phytochemical compounds such as allicin, diallyl disulfide (DADS), vinyldithiins, ajoenes (E-ajoene, Z-ajoene), diallyl trisulfide (DATS), micronutrient selenium (Se) etc. Organosulfur compounds are correlated with modulations in its antioxidant properties. The garlic compounds have also been recorded as promising immune-boosters or act as potent immunostimulants. A. sativum helps to treat cardiovascular ailments, neoplastic growth, rheumatism, diabetes, intestinal worms, flatulence, colic, dysentery, liver diseases, facial paralysis, tuberculosis, bronchitis, high blood pressure, and several other diseases. The present review aims to comprehensively enumerate the ethnobotanical and pharmacological aspects of A. sativum with notes on its phytochemistry, ethnopharmacology, toxicological aspects, and clinical studies from the retrieved literature from the last decade with notes on recent breakthroughs and bottlenecks. Future directions related to garlic research is also discussed.

In vitro anti-clostridial action and potential of the spice herbs essential oils to prevent biofilm formation of hypervirulent Clostridioides difficile strains isolated from hospitalized patients with CDI

BACKGROUND

Clostridioides difficile is the most common causative agent of antibiotic-acquired diarrhea in hospitalized patients associated with substantial morbidity and mortality. The global epidemic of CDI (Clostridioides difficile infection) began in the early 20th century with the emergence of the hypervirulent and resistant ribotype 027 strains, and requires an urgent search for new therapeutic agents.

OBJECTIVE

The aim of this study is to investigate the antibacterial activity of the three essential oils isolated from spice herbs (wild oregano, garlic and black pepper) against C. difficile clinical isolates belonging to 6 different PCR ribotypes and their potential inhibitory effect on the biofilm production in in vitro conditions.

RESULTS

Wild oregano essential oil showed strong inhibitory activity in concentrations 0.02-1.25 mg/mL and bactericidal activity in concentrations from 0.08 to 10 mg/mL. Garlic essential oil was effective in the concentration range of 0.02-40 mg/mL, and 0.16 - > 40 mg/mL. MIC and MBC for black pepper oil ranged from 0.04 to 40 mg/mL, and 0.08 - > 40 mg/mL, respectively. All the tested oils reduced in vitro biofilm production, with the best activity of oregano oil.

CONCLUSION

Essential oils of wild oregano, black pepper and garlic are candidates for adjunctive therapeutics in the treatment of CDI. Oregano oil should certainly be preferred due to the lack of selectivity of action in relation to the ribotype, the strength of the produced biofilm and/or antibiotic-susceptibility patterns.

S-Allyl cysteine in garlic (Allium sativum): Formation, biofunction, and resistance to food processing for value-added product development

S-allyl cysteine (SAC), which is the most abundant bioactive compound in black garlic (BG; Allium sativum), has been shown to have antioxidant, anti-apoptotic, anti-inflammatory, anti-obesity, cardioprotective, neuroprotective, and hepatoprotective activities. Sulfur compounds are the most distinctive bioactive elements in garlic. Previous studies have provided evidence that the concentration of SAC in fresh garlic is in the range of 19.0-1736.3 μg/g. Meanwhile, for processed garlic, such as frozen and thawed garlic, pickled garlic, fermented garlic extract, and BG, the SAC content increased to up to 8021.2 μg/g. BG is an SAC-containing product, with heat treatment being used in nearly all methods of BG production. Therefore, strategies to increase the SAC level in garlic are of great interest; however, further knowledge is required about the effect of processing factors and mechanistic changes. This review explains the formation of SAC in garlic, introduces its biological effects, and summarizes the recent advances in processing methods that can affect SAC levels in garlic, including heat treatment, enzymatic treatment, freezing, fermentation, ultrasonic treatment, and high hydrostatic pressure. Thus, the aim of this review was to summarize the outcomes of treatment aimed at maintaining or increasing SAC levels in BG. Therefore, publications from scientific databases in this field of study were examined. The effects of processing methods on SAC compounds were evaluated on the basis of the SAC content. This review provides information on the processing approaches that can assist food manufacturers in the development of value-added garlic products.

Deodorant Activity of Black Cumin Seed Essential Oil against Garlic Organosulfur Compound

The deodorant activity of black cumin (Nigella sativa L.) seed, a spice used to flavor curry and vegetable foods in Southwest Asia, against garlic (Allium sativum L.) organosulfur compounds related to human malodor was evaluated. Black cumin seed essential oil showed remarkable deodorant activity against garlic essential oil. The mode of action of this deodorant activity was presumed to be that black cumin seed essential oil covalently reacted with the organosulfur compounds in garlic. Therefore, thymoquinone, which is a major constituent in black cumin seed essential oil, and allyl mercaptan, which is one of the organosulfur compounds produced by cutting garlic, were reacted in vitro, and the products were purified and elucidated using spectroscopic data. As a result, these substances were identified as different allyl mercaptan adducts to dihydrothymoquinone. This chemical reaction was presumed to play a key role in the deodorant activity of black cumin seed essential oil.

In vitro and in vivo Anti-Toxoplasma Effects of Allium sativum Essential Oil Against Toxoplasma gondii RH Strain

Background

Since no effective vaccine has been developed for toxoplasmosis, prophylaxis in seronegative pregnant women and immunocompromised patients with a CD4 <100 cells/μL is highly recommended as an ideal strategy to prevent this disease. This study aimed to assess the chemical composition, in vitro, and in vivo effects of Allium sativum essential oil (ASEO) against Toxoplasma gondii RH strain.

Methods

The in vitro anti-Toxoplasma effects of different concentrations of ASEO (32.5, 75, 150 µg/mL) were measured by MTT assay for 0.5, 1, 2, and 3 h. Male Balb/c mice were orally administrated ASEO at the doses of 200, 400, and 600 µg/kg/day for 14 days. One day after the completion of oral drug administration, the mice in all groups were infected intraperitoneally with 1×10⁴ tachyzoites. They were checked daily and the rate of survival was recorded. The peritoneal fluids of the mice were collected and the mean number of tachyzoites was calculated via a light microscope. The level of liver lipid peroxidation (LPO) and nitric oxide (NO), toxicity effects on the liver and kidney, and the mRNA expression levels of some pro-inflammatory cytokines such as IL-1β and IFN-γ were determined by quantitative real-time PCR.

Results

Different concentrations of ASEO showed a significant (p < 0.001) anti-Toxoplasma activity against T. gondii tachyzoites, and the highest efficacy was observed at the concentration of 150 µg/mL. Fourteen days of pre-treatment of infected mice with ASEO at the doses of 200, 400, and 600 µg/kg/day significantly (p < 0.001) decreased the mean number of tachyzoites and mortality rate by the 6th, 7th, and 8th days after infection, respectively. ASEO at the doses of 200, 400, and 600 µg/kg/day significantly (p < 0.05) improved the increase in the LPO and NO. Pre-treatment of mice with different doses of ASEO provoked a considerable (P < 0.001) downregulation of IL-1β and IFN-γ mRNA gene expression levels, but it had no significant toxicity on the serum levels of some liver and kidney enzymes.

Conclusion

The present study demonstrated the considerable prophylactic effects of ASEO that increased the survival rate of mice and reduced the parasite load in them. Our findings also showed that ASEO promotes the innate immune system, pro-inflammatory cytokines, inhibition of hepatic injury, etc. in the mice with acute toxoplasmosis. However, additional investigations are mandatory to clarify the accurate prophylactic and therapeutic anti-Toxoplasma mechanisms of ASEO as well as all its toxicity aspects, especially in clinical settings.

Chemical Constituents, In Vitro Antioxidant Activity and In Silico Study on NADPH Oxidase of Allium sativum L. (Garlic) Essential Oil

Allium sativum L., also known as garlic, is a perennial plant widely used as a spice and also considered a medicinal herb since antiquity. The aim of this study was to determine by gas chromatography-mass spectrometry (GC-MS) the chemical profile fingerprint of the essential oil (EO) of one accession of Peruvian A. sativum (garlic), to evaluate its antioxidant activity and an in- silico study on NADPH oxidase activity of the volatile phytoconstituents. The antioxidant activity was tested using DPPH and β-carotene assays. An in-silico study was carried out on NADPH oxidase (PDB ID: 2CDU), as was ADMET prediction. The results indicated that diallyl trisulfide (44.21%) is the major component of the EO, followed by diallyl disulfide (22.08%), allyl methyl trisulfide (9.72%), 2-vinyl-4H-1,3-dithiine (4.78%), and α-bisabolol (3.32%). Furthermore, the EO showed antioxidant activity against DPPH radical (IC50 = 124.60 ± 2.3 µg/mL) and β-carotene bleaching (IC50 = 328.51 ± 2.0). The best docking score on NADPH oxidase corresponds to α-bisabolol (ΔG = -10.62 kcal/mol), followed by 5-methyl-1,2,3,4-tetrathiane (ΔG = -9.33 kcal/mol). Additionally, the volatile components could be linked to the observed antioxidant activity, leading to potential inhibitors of NADPH oxidase.

Antiaflatoxigenic potential of essential oils of spices – a review

Mycotoxins are important food contaminants posing a significant threat to food and feed safety and public health. Among the mycotoxins, aflatoxins are deemed to be a more significant contaminant due to their potent carcinogenic, and hepatotoxic effects, and their levels are highly regulated in the international food trade. Phytochemicals are considered a major source of natural antifungal agents. The volatile nature of essential oil of plants makes them ideal candidates for antifungal agents due to their ability to distribute in free air spaces in closed containers and penetrate through heterogeneous food materials. In these, essential oils in spices attain special attention due to their commercial availability and low toxicity. This article reviews the antiaflatoxigenic capacity of spice essential oils and the effect of essential oil composition on the activity and mechanism of antifungal action and is expected to be useful for the planning of further research in the subject area.

Mixing Oil-Based Microencapsulation of Garlic Essential Oil: Impact of Incorporating Three Commercial Vegetable Oils on the Stability of Emulsions

The active components in garlic essential oil are easily degradable, which limits its application in the food industry. Vegetable oils (VOs) were used to improve the stability of garlic essential oil (GEO) emulsion. The volatile compounds of GEO and its mixtures with vegetable oils (VOs), including corn oil (CO), soybean oil (SO), and olive oil (OO) indicated that GEO-VO mixtures had a higher percentage of Diallyl disulfide and Diallyl trisulfide than pure GEO. Adding an appropriate amount of VOs promoted the GEO emulsion (whey protein concentrate and inulin as the wall materials) stability in order of CO > SO > OO. Evaluation of the encapsulation efficiency, controlled release, and antimicrobial activity of GEO-VO microcapsules showed that the GEO was successfully entrapped and slowly released with active antibacterial activities on both E. coli and S. aureus. Collectively, these results implied that VOs, especially for 20% CO, improved the stability of GEO emulsions and the encapsulation efficiency of GEO microcapsules. The mechanism might be related to (1) the regulating effect of density difference between oil and water phases on prevention to gravitational separation, (2) the promotion to the compatibility of GEO and VOs to inhibit the phase separation caused by Ostwald ripening.

Cholesterol-lowering activity of natural mono- and sesquiterpenoid compounds in essential oils: A review and investigation of mechanisms using in silico protein-ligand docking

Mono- and sesquiterpenoids are the main chemical constituents of essential oils. Essential oils and their constituents have received increasing attention for lipid-lowering properties in both cell and animal models. Despite the chemical diversity of essential oil compounds, the effects of many of these compounds on cholesterol metabolism are highly similar. In this report, we review the literature regarding the effects of essential oils and their terpenoid constituents on cholesterol homeostasis, and explore likely mechanisms using protein-ligand docking. We identified 98 experimental and seven clinical studies on essential oils, isolated compounds, and blends; 100 of these described improvements either in blood cholesterol levels or in sterol metabolic pathways. Our review and docking analysis confirmed two likely mechanisms common to many essential oil compounds: (1) direct agonism of peroxisome-proliferator-activated receptors, and (2) direct interaction with sterol-sensing domains, motifs found in key sterol regulatory proteins including sterol regulatory element binding protein cleavage activating protein and HMG-CoA reductase. Notably, these direct interactions lead to decreased transcription and accelerated degradation of HMG-CoA reductase. Our work suggests that terpene derivatives in essential oils have cholesterol-lowering activity and could potentially work synergistically with statins, however, further high quality studies are needed to establish their clinical efficacy.

Diet, Immunity, and Microbiota Interactions: An Integrative Analysis of the Intestine Transcriptional Response and Microbiota Modulation in Gilthead Seabream (Sparus aurata) Fed an Essential Oils-Based Functional Diet

Essential oils (EOs) are promising alternatives to chemotherapeutics in animal production due to their immunostimulant, antimicrobial, and antioxidant properties, without associated environmental or hazardous side effects. In the present study, the modulation of the transcriptional immune response (microarray analysis) and microbiota [16S Ribosomal RNA (rRNA) sequencing] in the intestine of the euryhaline fish gilthead seabream (Sparus aurata) fed a dietary supplementation of garlic, carvacrol, and thymol EOs was evaluated. The transcriptomic functional analysis showed the regulation of genes related to processes of proteolysis and inflammatory modulation, immunity, transport and secretion, response to cyclic compounds, symbiosis, and RNA metabolism in fish fed the EOs-supplemented diet. Particularly, the activation of leukocytes, such as acidophilic granulocytes, was suggested to be the primary actors of the innate immune response promoted by the tested functional feed additive in the gut. Fish growth performance and gut microbiota alpha diversity indices were not affected, while dietary EOs promoted alterations in bacterial abundances in terms of phylum, class, and genus. Subtle, but significant alterations in microbiota composition, such as the decrease in Bacteroidia and Clostridia classes, were suggested to participate in the modulation of the intestine transcriptional immune profile observed in fish fed the EOs diet. Moreover, regarding microbiota functionality, increased bacterial sequences associated with glutathione and lipid metabolisms, among others, detected in fish fed the EOs supported the metabolic alterations suggested to potentially affect the observed immune-related transcriptional response. The overall results indicated that the tested dietary EOs may promote intestinal local immunity through the impact of the EOs on the host-microbial co-metabolism and consequent regulation of significant biological processes, evidencing the crosstalk between gut and microbiota in the inflammatory regulation upon administration of immunostimulant feed additives.

Investigation into SARS-CoV-2 Resistance of Compounds in Garlic Essential Oil

Eighteen active substances, including 17 organosulfur compounds found in garlic essential oil (T), were identified by GC-MS analysis. For the first time, using the molecular docking technique, we report the inhibitory effect of the considered compounds on the host receptor angiotensin-converting enzyme 2 (ACE2) protein in the human body that leads to a crucial foundation about coronavirus resistance of individual compounds on the main protease (PDB6LU7) protein of SARS-CoV-2. The results show that the 17 organosulfur compounds, accounting for 99.4% contents of the garlic essential oil, have strong interactions with the amino acids of the ACE2 protein and the main protease PDB6LU7 of SARS-CoV-2. The strongest anticoronavirus activity is expressed in allyl disulfide and allyl trisulfide, which account for the highest content in the garlic essential oil (51.3%). Interestingly, docking results indicate the synergistic interactions of the 17 substances, which exhibit good inhibition of the ACE2 and PDB6LU7 proteins. The results suggest that the garlic essential oil is a valuable natural antivirus source, which contributes to preventing the invasion of coronavirus into the human body.

Garlic essential oil mediates acute and chronic mild stress-induced depression in rats via modulation of monoaminergic neurotransmission and brain-derived neurotrophic factor levels

Garlic essential oil (GEO) and its major organosulfur component (diallyl disulfide, DADS) possess diverse biological properties; however, limited information on their antidepressant-like effects is available. This study is the first to investigate these effects of GEO using the forced swimming test (FST) and unpredictable chronic mild stress (UCMS) induced depression in rats. After oral administration for 28 consecutive days, GEO (25 and 50 mg per kg bw) significantly reduced the immobility time in the FST. Additionally, GEO and DADS significantly reversed the sucrose preference index decrease induced by 5 weeks of UCMS. GEO (25 mg per kg bw) effectively decreased the frontal cortex turnover ratio of serotonin (5-HT) and dopamine (DA), thus increasing the 5-HT and DA levels, with no hippocampal effects. Chronic GEO treatment increased hippocampal brain-derived neurotrophic factor (BDNF), c-AMP response element binding protein (CREB), and protein kinase B (AKT) expression, exhibiting its effects via monoamine neurotransmitter modulation and the BDNF-related signaling pathway.

Effect of essential oils on pathogenic and biofilm-forming Vibrio parahaemolyticus strains

In this study, the effect of three essential oils (EOs) - clove oil (CO), thyme oil (TO), and garlic oil (GO), which are generally recognized as safe - on the planktonic growth, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), motility, biofilm formation, and quorum sensing (QS) of Vibrio parahaemolyticus was investigated. All three EOs showed bacteriostatic activity, with MICs in the range 0.02%-0.09% (v/v). CO and TO completely controlled planktonic growth at 0.28% and 0.08% (v/v), which is four times their MIC (4 × MIC), after 10 min, whereas GO completely controlled growth at 0.36% (v/v) (4 × MIC) after treatment for 20 min. V. parahaemolyticus motility was significantly reduced by all three EOs at 4 × MIC (0.28% for CO, 0.08% for TO, and 0.36% for GO), whereas QS was controlled and biofilm formation reduced by all three EOs at 8 × MIC (0.56% for CO, 0.16% for TO, and 0.72% for GO) after 30 min of treatment. These results suggest that CO, TO, and GO have a significant inhibitory effect on V. parahaemolyticus cells in biofilm sand thus represent a promising strategy for improving food safety. These results provide the evidence required to encourage further research into the practical use of the proposed EOs in food preparation processes.

Chemical Composition and Combinatory Antifungal Activities of Ammoides verticillata, Allium sativum and Curcuma longa Essential Oils Against Four Fungi Responsible for Tomato Diseases

BACKGROUND

Tomato is considered a model plant in genetics and is one of the most economically important crops of all those that exist in the world. Several species of fungi are reported on tomato fruit, causing damage both during cultivation and after harvest. Some of the appropriate actions that could be initiated to resolve the problem are to develop and search for new antimicrobial substances isolated from the bioactive natural products, such as essential oils.

AIMS AND OBJECTIVE

The aim of this work was to determine the chemical composition of essential oils of Ammoides verticillata, Allium sativum and Curcuma longa, to evaluate their in-vitro antifungal activities and in-vivo antifungal effect of essential oils to prevent the diseases caused by tomato.

MATERIALS AND METHODS

The essential oils obtained from aerial parts of plants were analyzed by GC/MS and tested for their antifungal activities against Penicillium expansum, Fusarium solani, Rhizopus stolonifer and Alternaria alternata using the radial growth technique method. The effectiveness in-vivo of the association between Allium sativum and Curcuma longa essential oils was also investigated on tomatoes inoculated by fungi.

RESULTS

The essential oil from A. verticilata was mainly composed of phenolic compounds (54.4%), the A. sativum oil was mainly composed of sulfur compounds (91.5%) and C. longa oil was dominated by oxygenated monoterpenes (82.0%). The obtained results in-vitro antifungal revealed that individual essential oils of A. verticillata and A. sativum were more active than the essential oil of C. longa against all screened microorganisms. An important antifungal effect of A. sativum and C. longa essential oils blend was obtained against P. expansum (100%), F. solani (95.2%), R. stolonifer (95.1%) and A. alternata (48.5%). Furthermore, A. sativum and C. longa essential oils blends have demonstrated promising in-vivo antifungal activity to control infection of tomato against P. expansum and R. stolonifer.

CONCLUSION

A. sativum and C. longa essential oil blends can be used as a natural food preservative and alternative to chemical fungicides to protect stored tomato against many phytopathogens.

The potential for microwave technology and the ideal profile method to aid in salt reduction

This study was the first to evaluate the influence of the combination strategies of flavor addition and microwave-assisted thermal sterilization (MATS) processing for salt reduction implications. In freshly prepared mashed potatoes, a 30% and 50% salt reduction (w/w) in comparison to a 100% salt sample with three flavor variations (no additional flavor, garlic, and pepper) were investigated. Also, using the ideal profile method (IPM), the influence of MATS versus retort processing, in comparison to a freshly prepared sample, and flavor addition on mashed potato sensory properties and acceptance was investigated. Chemical characterization using the electronic tongue for nonvolatile compounds and headspace solid-phase microextraction (HS-SPME)/gas chromatography-mass spectrometry (GC-MS) for volatile analysis was completed. IPM revealed the ideal data were consistent at both the panel and consumer levels from a sensory and hedonic perspective. Results demonstrated the ideal mashed potato product would remain low in bitterness but have more intense pepper and potato aromas and flavors than the current samples evaluated. The salt level could be reduced by 50% while still maintaining flavor and overall acceptance in freshly prepared samples, but this was accompanied by a loss in saltiness intensity perception. The saltiness intensity was not different from the freshly prepared samples when processed via MATS but was different when processed by the retort. For chemical characterization, the electronic tongue showed a high discrimination index (>89%) and correlated highly (>0.8) with many sensory attributes. As salt concentration in the mashed potatoes decreased, the recovery of volatile compounds decreased. The present work contributes to the understanding of product reformulation for the purpose of salt reduction. PRACTICAL APPLICATION: Product developers need strategies to bring salt down to target levels while maintaining consumer acceptance. The combination strategies of flavor addition and MATS processing may allow for a new strategy to assist product developers in reaching salt reduction targets. Furthermore, developers should bear in mind that noticeable intensity differences may not alter the preference for the product. Thus, intensity differences that result in changes in acceptance should be the focus of quality insurance rather than utilizing just noticeable differences.

An Appraisal of Developments in Allium Sulfur Chemistry: Expanding the Pharmacopeia of Garlic

Alliums and allied plant species are rich sources of sulfur compounds that have effects on vascular homeostasis and the control of metabolic systems linked to nutrient metabolism in mammals. In view of the multiple biological effects ascribed to these sulfur molecules, researchers are now using these compounds as inspiration for the synthesis and development of novel sulfur-based therapeutics. This research has led to the chemical synthesis and biological assessment of a diverse array of sulfur compounds representative of derivatives of S-alkenyl-l-cysteine sulfoxides, thiosulfinates, ajoene molecules, sulfides, and S-allylcysteine. Many of these synthetic derivatives have potent antimicrobial and anticancer properties when tested in preclinical models of disease. Therefore, the current review provides an overview of advances in the development and biological assessment of synthetic analogs of allium-derived sulfur compounds.

Antimicrobial zein coatings plasticized with garlic and thyme essential oils

Abstract Essential oils with antimicrobial properties are widely used in the food industry. This study aimed to evaluate the influence of a blend of garlic (Allium sativum) and thyme (Thymus vulgaris) essential oils on the antimicrobial and mechanical properties of zein films. Four bacteria (Enteropathogenic Escherichia coli (EPEC), Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus) related to food contamination were chosen to evaluate the antimicrobial properties. The results indicated that the oil blend acted as a plasticizer, decreasing the glass transition temperature and the Young’s Modulus of the films. The addition of the oil blend also resulted in lower solubility and water absorption. The addition of the oil blend (0, 2%, 3% and 5% (v/v)) to the zein films showed inhibitory activity against all the bacteria tested, with inhibitory halos of between 6.5 mm and 8.27 mm. The results showed that the coating could be applied as a support to increase the shelf life of food products.

Antifungal activity of Gallesia integrifolia fruit essential oil

Gallesia integrifolia (Phytolaccaceae) is native to Brazil and has a strong alliaceous odor. The objective of this study was to identify the chemical composition of G. integrifolia fruit essential oil and evaluate fungicidal activity against the main food-borne diseases and food spoilage fungi. The essential oil was extracted by hydrodistillation and identified by GC-MS. From 35 identified compounds, 68% belonged to the organosulfur class. The major compounds were dimethyl trisulfide (15.49%), 2,8-dithianonane (52.63%) and lenthionine (14.69%). The utilized fungi were Aspergillus fumigatus, Aspergillus niger, Aspergillus ochraceus, Aspergillus versicolor, Penicillium funiculosum, Penicillium ochrochloron, Penicillium verrucosum var. cyclopium, and Trichoderma viride. Minimal fungicidal concentration for the essential oil varied from 0.02 to 0.18mg/mL and bifonazole and ketoconazole controls ranged from 0.20 to 3.50mg/mL. The lower concentration of the essential oil was able to control P. ochrochloron, A. fumigatus, A. versicolor, A. ochraceus and T. viride. This study shows a high fungicidal activity of G. integrifolia fruit essential oil and can support future applications by reducing the use of synthetic fungicides.

Formulation and characterization of garlic (Allium sativum L.) essential oil nanoemulsion and its acaricidal activity on eriophyid olive mites (Acari: Eriophyidae)

Green and nanoacaricides including essential oil (EO) nanoemulsions are important compounds to provide new, active, safe acaricides and lead to improvement of avoiding the risk of synthetic acaricides. This study was carried out for the first time on eriophyid mites to develop nanoemulsion of garlic essential oil by ultrasonic emulsification and evaluate its acaricidal activity against the two eriophyid olive mites Aceria oleae Nalepa and Tegolophus hassani (Keifer). Acute toxicity of nanoemulsion was also studied on male rats. Garlic EO was analyzed by gas chromatography-mass spectrometry (GC-MS), and the major compounds were diallyl sulfide (8.6%), diallyl disulfide (28.36%), dimethyl tetrasulfide (15.26%), trisulfide,di-2-propenyl (10.41%), and tetrasulfide,di-2-propenyl (9.67%). Garlic oil nanoemulsion with droplet size 93.4 nm was formulated by ultrasonic emulsification for 35 min. Emulsification time and oil and surfactant ratio correlated to the emulsion droplet size and stability. The formulated nanoemulsion showed high acaricidal activity against injurious eriophyid mites with LC₅₀ 298.225 and 309.634 μg/ml, respectively. No signs of nanoemulsion toxicity were noted in treating rats; thus, it may be considered non-toxic to mammals. Stability of garlic oil nanoemulsion, high acaricidal activity, and the absence of organic toxic solvents make the formulation that may be a possible acaricidal product. Results suggest the possibility of developing suitable natural nanoacaricide from garlic oil.

Characterization of Essential Oils Obtained from Abruzzo Autochthonous Plants: Antioxidant and Antimicrobial Activities Assessment for Food Application

In the present study, the essential oils (EOs) of some officinal plants from Abruzzo territory (Italy) were evaluated for their antimicrobial and antioxidant activities and their volatile fraction chemical characterization. The EOs were extracted from Rosmarinus officinalis, Origanum vulgare, Salvia officinalis, Mentha piperita, Allium sativum, Foeniculum vulgare, Satureja montana, Thymus vulgaris and Coriandrum sativum seeds. The antimicrobial activity was screened against thirteen Gram-positive and Gram-negative strains to determine the Minimal Inhibitory Concentration (MIC). The total phenolic content (TPC) and the antioxidant capacity (AOC) were assessed by means of Folin-Ciocâlteu method, and Trolox Equivalent Antioxidant Capacity with 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (TEAC/ABTS), Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays respectively. Among the nine EOs tested, T. vulgaris, S. montana, O. vulgare and C. sativum EOs showed MIC values ranging from 0.625 to 5 μL/mL. The AOC and TPC results for these species were also interesting. The major components for these EOs were thymol for T. vulgaris (44%) and O. vulgare (40%), linalool (77%) for C. sativum, and carvacrol for S. montana (54%). The results allowed the study to establish that these EOs are good candidates for potential application as biopreservatives in foods and/or food manufacture environments.

The Chemical Compositions of the Volatile Oils of Garlic (Allium sativum) and Wild Garlic (Allium vineale)

Garlic, Alliumsativum, is broadly used around the world for its numerous culinary and medicinal uses. Wild garlic, Allium vineale, has been used as a substitute for garlic, both in food as well as in herbal medicine. The present study investigated the chemical compositions of A. sativum and A. vineale essential oils. The essential oils from the bulbs of A. sativum, cultivated in Spain, were obtained by three different methods: laboratory hydrodistillation, industrial hydrodistillation, and industrial steam distillation. The essential oils of wild-growing A. vineale from north Alabama were obtained by hydrodistillation. The resulting essential oils were analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Both A. sativum and A. vineale oils were dominated by allyl polysulfides. There were minor quantitative differences between the A. sativum oils owing to the distillation methods employed, as well as differences from previously reported garlic oils from other geographical locations. Allium vineale oil showed a qualitative similarity to Allium ursinum essential oil. The compositions of garlic and wild garlic are consistent with their use as flavoring agents in foods as well as their uses as herbal medicines. However, quantitative differences are likely to affect the flavor and bioactivity profiles of these Allium species.

Effect of feeding garlic leaves on rumen fermentation, methane emission, plasma glucose kinetics, and nitrogen utilization in sheep

Background

Garlic and its constituents are reported to have been effective in reducing methane emission and also influence glucose metabolism in body; however, studies in ruminants using garlic leaves are scarce. Garlic leaves contain similar compounds as garlic bulbs, but are discarded in field after garlic bulb harvest. We speculate that feeding garlic leaves might show similar effect as garlic constituents in sheep and could be potential animal feed supplement. Thus, we examined the effect of freeze dried garlic leaves (FDGL) on rumen fermentation, methane emission, plasma glucose kinetics and nitrogen utilization in sheep.

Methods

Six sheep were fed Control diet (mixed hay and concentrate (60:40)) or FDGL diet (Control diet supplemented with FDGL at 2.5 g/kg BW^0.75 of sheep) using a crossover design. Methane gas emission was measured using open-circuit respiratory chamber. Plasma glucose turnover rate was measured using isotope dilution technique of [U-¹³C]glucose. Rumen fluid, feces and urine were collected to measure rumen fermentation characteristics and nitrogen utilization.

Result

No significant difference in rumen fermentation parameters was noticed except for rumen ammonia tended to be higher (0.05 < P < 0.1) in FDGL diet. Methane emission per kg dry matter ingested and methane emission per kg dry matter digested were lower (P < 0.05) in FDGL diet. Plasma glucose concentration was similar between diets and plasma glucose turnover rate tended to be higher in FDGL diet (0.05 < P < 0.1). Nitrogen retention was higher (P < 0.05) and microbial nitrogen supply tended to be higher (0.05 < P < 0.1) in FDGL diet.

Conclusion

FDGL diet did not impair rumen fermentation, improved nitrogen retention; while absence of significant results in reduction of methane emission, glucose turnover rate and microbial nitrogen supply, further studies at higher dose would be necessary to conclude the merit of FDGL as supplement in ruminant feedstuff.

Think Yellow and Keep Green-Role of Sulfanes from Garlic in Agriculture

Reactive sulfur species from garlic have long been renowned for their health benefits and antimicrobial properties. In agriculture the subject matter is now gathering momentum in the search for new bio-pesticides to addressing emerging environmental concerns and tighter restrictions on the use of many conventional chemical pesticides. Although the precise modes of action of these garlic-derived bioactives is complex, recent research has provided a number of new insights that deepen our understanding of garlic-derived products, such as garlic extracts and oils. Herein, their activity against various crop-damaging pests is reviewed. In many cases, there seems to be a broad range of activity associated with the sulfur-containing compounds derived from Allium species, which manifests itself in diverse insecticidal, antifungal, and nematicidal activities. These activities open a new understanding to develop this natural chemistry as a "green pesticide".

Chemical and biochemical mechanisms underlying the cardioprotective roles of dietary organopolysulfides

Foods that are rich in organosulfides are highly regarded for their broad range of functions in disease prevention and health promotion since ancient time yet modern scientific study, particularly clinical studies could not agree with traditional wisdom. One of the complexities is due to the labile nature of organosulfides, which are often transformed to different structures depending on the processing conditions. The recent evidence on polysulfides as H₂S donors may open up a new avenue for establishing structure and health promotion activity relationship. To put this development into perspective, we carried out a review on the recent progress on the chemistry and biochemistry of organopolysulfides with emphasis on their cardioprotective property. First, we briefly surveyed the foods that are rich in polysulfides and their structural diversity. This is followed by in-depth discussion on the chemical transformations of polysulfides under various processing conditions. We further reviewed the potential action mechanisms of polysulfides in cardioprotection through: (a) hydrogen sulfide releasing activity; (b) radical scavenging activity; and (c) activity in enzyme inhibition and intervention of gene regulation pathways. Based on the literature trend, we can conclude that the emerging concept of organopolysulfides as naturally occurring H₂S donors is intriguing and warrants further research to establish the structure and activity relationship of the organopolysulfides as H₂S donors.