Antibacterial Activities of Wasabi against Escherichia coli O157:H7 and Staphylococcus aureus

Determination of the Optimal Concentration of Natural Antimicrobial Agents in Marinade Sauce for Meal Kits

This study aimed to determine the antimicrobial effectiveness of natural antimicrobial agents (NAAs) (yuzu juice, wasabi extract, and rosemary extract) against three target microorganisms (TMs) (Escherichia coli, Staphylococcus aureus, and Salmonella Typhimurium) and to determine the optimal concentration of these agents using response surface methodology (RSM) to ensure the safety of meal kits manufactured using marinade sauce. The three NAAs added to marinade sauce effectively inactivated TMs (P<0.05), in particular, yuzu juice had the greatest antimicrobial effect against TMs, followed by wasabi and rosemary extracts. To determine the optimal concentration of NAAs using RSM, 17 concentrations were tested with three TMs as dependent variables and three NAAs as independent variables. The results showed that E. coli was not present under any of the conditions tested, whereas S. aureus and S. Typhimurium exhibited different characteristics depending on the conditions. Through response surface analysis of the TMs except for E. coli, which was not detected, it was determined that S. aureus had a coefficient of determination (R2) of 0.928 and a lack of fit of 0.074, and the linear regression of [yuzu juice] (X1) and quadratic regression of [yuzu juice]2 (X12) were both significant (P<0.05). S. Typhimurium had an R2 of 0.8955 and a lack of fit of 0.051, and only the quadratic regression of [yuzu juice]2 (X12) was significant (P<0.05). Based on RSM and ridge analysis, the optimal mixed conditions were determined to be 3.92% (v/w) yuzu juice, 23.41% (v/w) wasabi extract, and 3.93% (v/w) rosemary extract. After investigating the antimicrobial effect under the optimal conditions, E. coli and S. Typhimurium were absent, and S. aureus was reduced to 2.50 ± 0.09 log colony-forming units/g after 24 h. The results indicated that mixed treatment with the three NAAs had a more significant antimicrobial effect due to their synergistic properties compared to when used in isolation.

Screening for Fungicide Efficacy in Controlling Blackleg Disease in Wasabi (Eutrema japonicum)

Blackleg disease is devastating for wasabi (Eutrema japonicum) production, occurring at any time and everywhere within the main production area of the Sichuan Province, China. There have been very few studies on the chemical control of this disease. In this study, we isolated and identified a local popular strain of the pathogen Plenodomus wasabiae. The isolated fungus strain caused typical disease spots on the leaves and rhizomes upon inoculation back to wasabi seedlings. The symptoms of blackleg disease developed very quickly, becaming visible on the second day after exposure to P. wasabiae and leading to death within one week. We then evaluated the efficacy of ten widely used fungicides to screen out effective fungicides. The efficacy of the tested fungicides was determined through mycelial growth inhibition on medium plates. As a result, tebuconazole and pyraclostrobin were able to inhibit the mycelial growth of P. wasabiae, and the most widely used dimethomorph in local production areas produced the lowest inhibition activity (13.8%). Nevertheless, the highest control efficacy of tebuconazole and pyraclostrobin on wasabi seedlings was only 47.48% and 39.03%, respectively. Generally, the control efficacy of spraying the fungicide before inoculation was better than that after inoculation. An increase in the application concentration of the two fungicides did not proportionately result in improved performance. We cloned the full-length sequence of sterol 14-demethylase (CYP51) and cytochrome B (CYTB) of which the mutations may contribute to the possible antifungalresistance. These two genes of the isolated fungus do not possess any reported mutations that lead to fungicide resistance. Previous studies indicate that there is a significant difference between fungicides in terms of the effectiveness of controlling blackleg disease; however, the control efficacy of fungicides is limited in blackleg control. Therefore, field management to prevent wound infection and unfavorable environmental conditions are more important than pesticide management.

Antibacterial mechanism of vanillin against Escherichia coli O157: H7

Vanillin, a plant-derived antimicrobial volatile substance, has potential microbial control applications in the food industry. However, the effect of vanillin on the food-borne pathogen Escherichia coli (E. coli) O157:H7 has not been well studied. This study aims to explore the antibacterial mechanism of vanillin against E. coli O157:H7. The minimum inhibitory concentration (MIC) and antibacterial effect of vanillin were determined by microdilution. Scanning electron microscopy (SEM) was used to observe the damage of vanillin to the cell membrane, while cell membrane potential and the leakage of nucleic acid protein were measured to explore the effect of vanillin on the membrane system. Confocal laser scanning and intracellular adenosine triphosphate (ATP) concentration determination were utilized to investigate the effects of vanillin on the energy, life, and death of E. coli. Finally, transcriptome sequencing was conducted to investigate the gene expression differences induced by vanillin treatment. The results showed that vanillin treatment effectively controlled E. coli O157:H7 with an MIC of 2 mg/mL. After treatment, damage to the membrane system, depolarization of the membrane, and leakage of nucleic acid and protein were observed. Meanwhile, vanillin treatment caused decreased ATP content and cell death. Transcriptome analysis showed that vanillin treatment significantly affected the expression of genes involved in cell membrane formation, tricarboxylic acid (TCA) cycling pathway, and oxidative phosphorylation pathway in E. coli O157:H7. In conclusion, membrane damage and energy metabolism disruption are important mechanisms of vanillin's inhibitory effect on E. coli O157:H7. This study provides new insights into the molecular reaction mechanism of vanillin against E. coli O157:H7, highlighting its potential as an antibacterial substance for preventing E. coli contamination in the food industry.

An Assessment of the In Vitro Models and Clinical Trials Related to the Antimicrobial Activities of Phytochemicals

An increased number antibiotic-resistant bacteria have emerged with the rise in antibiotic use worldwide. As such, there has been a growing interest in investigating novel antibiotics against antibiotic-resistant bacteria. Due to the extensive history of using plants for medicinal purposes, scientists and medical professionals have turned to plants as potential alternatives to common antibiotic treatments. Unlike other antibiotics in use, plant-based antibiotics have the innate ability to eliminate a broad spectrum of microorganisms through phytochemical defenses, including compounds such as alkaloids, organosulfur compounds, phenols, coumarins, and terpenes. In recent years, these antimicrobial compounds have been refined through extraction methods and tested against antibiotic-resistant strains of Gram-negative and Gram-positive bacteria. The results of the experiments demonstrated that plant extracts successfully inhibited bacteria independently or in combination with other antimicrobial products. In this review, we examine the use of plant-based antibiotics for their utilization against antibiotic-resistant bacterial infections. In addition, we examine recent clinical trials utilizing phytochemicals for the treatment of several microbial infections.

Growth of ɣ-Proteobacteria in Low Salt Cucumber Fermentation Is Prevented by Lactobacilli and the Cover Brine Ingredients

This study investigated the ability of ɣ-proteobacteria, indigenous to fresh cucumber, to grow in the expressed fruit juice (CJM) and fermentation. It was hypothesized that fresh cucumbers can support prolific growth of ɣ-proteobacteria but that the cover brine composition and acid production by the competing lactobacilli in the fermentation of the fruit act as inhibitory agents. The ɣ-proteobacteria proliferated in CJM with an average maximum growth rate (μmax) of 0.3895 ± 0.0929 and doubling time (Td) of 1.885 ± 0.465/h. A significant difference was found between the ɣ-proteobacteria μmax and Td relative to Lactiplantibacillus pentosus LA0445 (0.2319 ± 0.019; 2.89/h) and Levilactobacillus brevis 7.2.43 (0.221 ± 0.015; 3.35/h) but not Lactiplantibacillus plantarum 3.2.8 (0.412 ± 0.119; 1.87/h). While inoculation level insignificantly altered the μmax and Td of the bacteria tested; it impacted the length of lag and stationary phases for the lactobacilli. Unlike the lactobacilli, the ɣ-proteobacteria were inhibited in CJM supplemented with a low salt fermentation cover brine containing calcium chloride, acetic acid and potassium sorbate. The ɣ-proteobacteria, P. agglomerans, was unable to proliferate in cucumber fermentations brined with calcium chloride at a pH of 6.0 ± 0.1 and the population of Enterobacteriaceae was outcompeted by the lactobacilli within 36 h. Together these observations demonstrate that the prolific growth of ɣ-proteobacteria in CJM is not replicated in cucumber fermentation. While the ɣ-proteobacteria growth rate is faster that most lactobacilli in CJM, their growth in cucumber fermentation is prevented by the cover brine and the acid produced by the indigenous lactobacilli. Thus, the lactobacilli indigenous to cucumber and cover brine composition influence the safety and quality of fermented cucumbers. IMPORTANCE While the abundance of specific ɣ-proteobacteria species varies among vegetable type, several harbor Enterobacteriaceae and Pseudomonadaceae that benefit the plant system. It is documented that such bacterial populations decrease in density early in vegetable fermentations. Consequently, it is assumed that they do not contribute to the quality of finished products. This study explored the viability of ɣ-proteobacteria in CJM, used as a model system, CJM supplemented with fermentation cover brine and cucumber fermentation, which are characterized by an extremely acidic endpoint pH (3.23 ± 0.17; n = 391). The data presented demonstrates that fresh cucumbers provide the nutrients needed by ɣ-proteobacteria to proliferate and reduce pH to 4.47 ± 0.12. However, ɣ-proteobacteria are unable to proliferate in cucumber fermentation. Control of ɣ-proteobacteria in fermentations depends on the cover brine constituents and the indigenous competing lactobacilli. This knowledge is of importance when developing guidelines for the safe fermentation of vegetables, particularly with low salt.

Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity

For decades, various plants have been studied as sources of biologically active compounds. Compounds with anticancer and antimicrobial properties are the most frequently desired. Cruciferous plants, including Brussels sprouts, broccoli, and wasabi, have a special role in the research studies. Studies have shown that consumption of these plants reduce the risk of lung, breast, and prostate cancers. The high chemopreventive and anticancer potential of cruciferous plants results from the presence of a large amount of glucosinolates, which, under the influence of myrosinase, undergo an enzymatic transformation to biologically active isothiocyanates (ITCs). Natural isothiocyanates, such as benzyl isothiocyanate, phenethyl isothiocyanate, or the best-tested sulforaphane, possess anticancer activity at all stages of the carcinogenesis process, show antibacterial activity, and are used in organic synthesis. Methods of synthesis of sulforaphane, as well as its natural or synthetic bifunctional analogues with sulfinyl, sulfanyl, sulfonyl, phosphonate, phosphinate, phosphine oxide, carbonyl, ester, carboxamide, ether, or additional isothiocyanate functional groups, and with the unbranched alkyl chain containing 2-6 carbon atoms, are discussed in this review. The biological activity of these compounds are also reported. In the first section, glucosinolates, isothiocyanates, and mercapturic acids (their metabolites) are briefly characterized. Additionally, the most studied anticancer and antibacterial mechanisms of ITC actions are discussed.

Influence of rapeseed, canola meal and glucosinolate metabolite (AITC) as potential antimicrobials: effects on growth performance, and gut health in Salmonella Typhimurium challenged broiler chickens

Poultry is the major sources of foodborne salmonellosis. Antibiotic resistance and a surge in zoonotic diseases warrant the use of natural alternatives. Glucosinolates (GLs) are naturally occurring antimicrobial compounds in rapeseed and canola. This study investigated the effect of feeding rapeseed, canola meal, and allyl isothiocyanate (AITC; Brassica secondary metabolites) on growth performance (GP), gut health, and the potential antimicrobial activity against nalidixic acid-resistant Salmonella Typhimurium (STNR) in chickens. A total of 640 one-day-old male Cobb 500 broilers were randomly allocated to 8 treatments with 8 replicated cages and 10 birds per cage. Dietary treatments were nonchallenge control (NC, corn-SBM based), challenge (Salmonella) control (CC), 10% rapeseed (10RS), 30% rapeseed (30RS), 20% canola meal (20CLM), 40% canola meal (40CLM), 500 ppm AITC (500AITC), and 1,500 ppm AITC (1500AITC). On d 1, all the birds except NC were orally challenged with STNR (7 log CFU/bird). The chickens were reared for 21 d, and their FI and BW were recorded weekly. Salmonella cecal colonization and fecal shedding were quantified, whereas organ translocation (OT) of STNR to the spleen, liver, and kidney was tested on 0, 3, 6, 13, and 20-d postchallenge (dpc). Data were subjected to one-way ANOVA, and the means were separated by Duncan's test, except mortality and OT data analyzed after transformation by square root of (n +1) (P < 0.05). Overall, feeding 30RS resulted in reduced BW (P = 0.003), BWG (P = 0.003), and FI (P = 0.001) compared to CC, 500AITC, and 1500AITC. Similarly, feeding 20CLM resulted in lower BW and BWG compared to CC (P < 0.05) and increased FCR compared to 1500AITC (P = 0.03). Feeding CC resulted in higher mortality compared to NC and 30RS (P = 0.03). Cecal colonization of STNR was reduced (P < 0.0001) for 30RS on 6 dpc and 500AITC on 6 and 13 dpc (P < 0.0001). Although no difference in gut permeability was observed 6 dpc (P > 0.05), OT of STNR population was the highest for CC in the spleen (P = 0.05). In the liver, 10RS showed reduced OT compared to 20CLM on 13 dpc (P = 0.03), whereas 30RS showed the lowest OT on 6 dpc in the kidney. Fecal shedding was lowest for 30RS on 6 dpc (P = 0.004). Histomorphology showed 30RS had the highest duodenum (P = 0.01) and jejunum (P = 0.02) villus height (VH) and VH to crypt depth (CD) ratio compared to the other treatments, whereas 1500AITC showed similar results to 30RS. Both 30RS and 1500AITC contained comparatively higher functional GL metabolites and were able to maintain gut health. Including higher levels of rapeseed or AITC in poultry feed can reduce Salmonella colonization in the feces and their translocation to other organs.

Natural Compounds With Antimicrobial and Antiviral Effect and Nanocarriers Used for Their Transportation

Due to the increasing prevalence of life-threatening bacterial, fungal and viral infections and the ability of these human pathogens to develop resistance to current treatment strategies, there is a great need to find and develop new compunds to combat them. These molecules must have low toxicity, specific activity and high bioavailability. The most suitable compounds for this task are usually derived from natural sources (animal, plant or even microbial). In this review article, the latest and most promising natural compounds used to combat bacteria, filamentous fungi and viruses are presented and evaluated. These include plant extracts, essential oils, small antimicrobial peptides of animal origin, bacteriocins and various groups of plant compounds (triterpenoids; alkaloids; phenols; flavonoids) with antimicrobial and antiviral activity. Data are presented on the inhibitory activity of each natural antimicrobial substance and on the putative mechanism of action against bacterial and fungal strains. The results show that among the bioactive compounds studied, triterpenoids have significant inhibitory activity against coronaviruses, but flavonoids have also been shown to inhibit SARS-COV-2. The last chapter is devoted to nanocarriers used to improve stability, bioavailability, cellular uptake/internalization, pharmacokinetic profile and reduce toxicity of natural compunds. There are a number of nanocarriers such as liposomes, drug delivery microemulsion systems, nanocapsules, solid lipid nanoparticles, polymeric micelles, dendrimers, etc. However, some of the recent studies have focused on the incorporation of natural substances with antimicrobial/antiviral activity into polymeric nanoparticles, niosomes and silver nanoparticles (which have been shown to have intrinsic antimicrobial activity). The natural antimicrobials isolated from animals and microorganisms have been shown to have good inhibitory effect on a range of pathogens, however the plants remain the most prolific source. Even if the majority of the studies for the biological activity evaluation are in silico or in vitro, their internalization in the optimum nanocarriers represents the future of “green therapeutics” as shown by some of the recent work in the field.

Review on the Antibacterial Mechanism of Plant-Derived Compounds against Multidrug-Resistant Bacteria (MDR)

Microbial resistance has progressed rapidly and is becoming the leading cause of death globally. The spread of antibiotic-resistant microorganisms has been a significant threat to the successful therapy against microbial infections. Scientists have become more concerned about the possibility of a return to the pre-antibiotic era. Thus, searching for alternatives to fight microorganisms has become a necessity. Some bacteria are naturally resistant to antibiotics, while others acquire resistance mainly by the misuse of antibiotics and the emergence of new resistant variants through mutation. Since ancient times, plants represent the leading source of drugs and alternative medicine for fighting against diseases. Plants are rich sources of valuable secondary metabolites, such as alkaloids, quinones, tannins, terpenoids, flavonoids, and polyphenols. Many studies focus on plant secondary metabolites as a potential source for antibiotic discovery. They have the required structural properties and can act by different mechanisms. This review analyses the antibiotic resistance strategies produced by multidrug-resistant bacteria and explores the phytochemicals from different classes with documented antimicrobial action against resistant bacteria, either alone or in combination with traditional antibiotics.

6-(methylsulfinyl)hexyl isothiocyanate (6-MITC) from Wasabia japonica alleviates inflammatory bowel disease (IBD) by potential inhibition of glycogen synthase kinase 3 beta (GSK-3β)

Inflammatory bowel disease (IBD) describes a set of disorders involving alterations to gastrointestinal physiology and mucosal immunity. Unravelling its complex pathophysiology is important since many IBD patients are refractory to or suffer adverse side effects from current treatments. Isothiocyanates (ITCs), such as 6-(methylsulfinyl)hexyl ITC (6-MITC) in Wasabia japonica, have potential anti-inflammatory activity. We aimed to elucidate the pathways through which 6-MITC alleviates inflammation by examining its role in the nuclear factor-kappa B (NF-κB) pathway through inhibition of glycogen synthase kinase 3 beta (GSK-3β) using a chemically induced murine model of IBD, cell-based and in silico techniques. The effects of 6-MITC and two NF-κB inhibitors, sulfasalazine (SS), pyrrolidine dithiolcarbamate (PDTC) were investigated on a dextran sulfate sodium (DSS)-induced murine mouse model of acute and chronic colitis using macroscopic measurements and pro-inflammatory markers. The effect of 6-MITC on NF-κB induction was assessed using a murine macrophage cell line. Complexes of GSK-3β-6-MITC and GSK-3β-ATP were generated in silico to elucidate the mechanism of 6-MITC's direct inhibition of GSK-3β. Changes in pro-inflammatory markers, inducible nitric oxide synthase (iNOS) (increased) and interleukin-6 (IL-6) (decreased) demonstrated that iNOS regulation occurred at the translational level. Intraperitoneal (ip) injection of 6-MITC to the colitis-induced mice ameliorated weight loss whereas oral administration had negligible effect. Fecal blood and colon weight/length ratio parameters improved on treatment with 6-MITC and the other NF-κB inhibitors. Levels of NF-κB decreased upon addition of 6-MITC in vitro while structural studies showed 6-MITC acts competitively to inhibit GSK-3β at the ATP binding site. In this study we demonstrated that 6-MITC inhibits NF-κB signaling via GSK-3β inhibition ameliorating fecal blood, colonic alterations and DSS-induced weight loss indirectly indicating reduced intestinal stress. Taken together these results suggest a role for 6-MITC in the treatment of IBD acting to alleviate inflammation through the GSK-3β/NF-κB pathway. Furthermore, the GSK-3β-6-MITC model can be utilized as a basis for development of novel therapeutics targeting GSK-3β for use in other disorders including cancer.

Synergistic anti-biofilm effects of Brassicaceae plant extracts in combination with proteinase K against Escherichia coli O157:H7

Bacteria can form biofilms, complex microbial communities protected from environmental stress, on food contact surfaces. Brassicaceae plant has been shown to contain bioactive compounds with antimicrobial activities. The objective of this study was to evaluate the synergistic effects of Brassicaceae species and proteinase K against E. coli O157:H7 biofilm. We determined the minimum biofilm inhibitory concentration, the fractional inhibitory concentration indexes, and the synergistic inhibitory effect of Raphanus sativus var. longipinnatus, R. sativus, and Brassica oleracea var. acephala extracts with proteinase K on E. coli O157:H7. The biofilm showed a 49% reduction with 2 mg/mL R. sativus. The combination of proteinase K 25 µg/mL significantly increased the effect of 2 mg/mL R. sativus var. longipinnatus and the combined treatment yielded up to 2.68 log reduction on stainless steel coupons. The results showed that the combination of R. sativus var. longipinnatus extract and proteinase K could serve as an anti-biofilm agent with synergistic effects for inhibiting E. coli O157:H7 biofilm on stainless steel surfaces.

Potential Role of Plant Extracts and Phytochemicals Against Foodborne Pathogens

Foodborne diseases are one of the major causes of morbidity and mortality, especially in low-income countries with poor sanitation and inadequate healthcare facilities. The foremost bacterial pathogens responsible for global outbreaks include Salmonella species, Campylobacter jejuni, Escherichia coli, Shigella sp., Vibrio, Listeria monocytogenes and Clostridium botulinum. Among the viral and parasitic pathogens, norovirus, hepatitis A virus, Giardia lamblia, Trichinella spiralis, Toxoplasma and Entamoeba histolytica are commonly associated with foodborne diseases. The toxins produced by Staphylococcus aureus, Bacillus cereus and Clostridium perfringens also cause these infections. The currently available therapies for these infections are associated with various limited efficacy, high cost and side-effects. There is an urgent need for effective alternative therapies for the prevention and treatment of foodborne diseases. Several plant extracts and phytochemicals were found to be highly effective to control the growth of these pathogens causing foodborne infections in in vitro systems. The present review attempts to provide comprehensive scientific information on major foodborne pathogens and the potential role of phytochemicals in the prevention and treatment of these infections. Further detailed studies are necessary to evaluate the activities of these extracts and phytochemicals along with their mechanism of action using in vivo models.

Review on plant antimicrobials: a mechanistic viewpoint

Microbial resistance to classical antibiotics and its rapid progression have raised serious concern in the treatment of infectious diseases. Recently, many studies have been directed towards finding promising solutions to overcome these problems. Phytochemicals have exerted potential antibacterial activities against sensitive and resistant pathogens via different mechanisms of action. In this review, we have summarized the main antibiotic resistance mechanisms of bacteria and also discussed how phytochemicals belonging to different chemical classes could reverse the antibiotic resistance. Next to containing direct antimicrobial activities, some of them have exerted in vitro synergistic effects when being combined with conventional antibiotics. Considering these facts, it could be stated that phytochemicals represent a valuable source of bioactive compounds with potent antimicrobial activities.

Inhibiting plasmid mobility: The effect of isothiocyanates on bacterial conjugation

Bacterial conjugation is the main mechanism for the transfer of multiple antimicrobial resistance genes among pathogenic micro-organisms. This process may be controlled by compounds that inhibit bacterial conjugation. In this study, the effects of allyl isothiocyanate, l-sulforaphane, benzyl isothiocyanate, phenylethyl isothiocyanate and 4-methoxyphenyl isothiocyanate on the conjugation of broad-host-range plasmids harbouring various antimicrobial resistance genes in Escherichia coli were investigated, namely plasmids pKM101 (IncN), TP114 (IncI₂), pUB307 (IncP) and the low-copy-number plasmid R7K (IncW). Benzyl isothiocyanate (32 mg/L) significantly reduced conjugal transfer of pKM101, TP114 and pUB307 to 0.3 ± 0.6%, 10.7 ± 3.3% and 6.5 ± 1.0%, respectively. l-sulforaphane (16 mg/L; transfer frequency 21.5 ± 5.1%) and 4-methoxyphenyl isothiocyanate (100 mg/L; transfer frequency 5.2 ± 2.8%) were the only compounds showing anti-conjugal specificity by actively reducing the transfer of R7K and pUB307, respectively.

Modeling the Survival of Escherichia coli O157:H7 Under Hydrostatic Pressure, Process Temperature, Time and Allyl Isothiocyanate Stresses in Ground Chicken Meat

Shiga toxin-producing Escherichia coli O157:H7 (STEC) is a common contaminant in meat and poultry. We investigated the use of non-thermal high pressure processing (HPP), with or without allyl isothiocyanate (AITC) essential oil, to kill STEC in ground chicken meat. Temperature was found an important factor affecting the inactivation of STEC in addition to pressure and process time. A full factorial experiment design (4 factors × 2 levels) was used to facilitate and evaluate the effect of pressure (250–350 MPa), operation temperature (−15–4°C), AITC concentration (0.05–0.15%, w/w), and pressure-holding time (10–20 min) on the inactivation of STEC. A linear model (a polynomial equation) was developed to predict/describe those four parameters’ impact on E. coli O157:H7 survival (R² = 0.90), as well as a dimensionless non-linear model. Both types of models were validated with data obtained from separate experimental points. The dimensionless model also demonstrated that it may predict the lethality (defined as the log CFU/g reduction of STEC before and after treatment) reasonably well with some factors set slightly outside the design ranges (e.g., a wider application than the linear model). The results provide important information regarding STEC survival as affected by HPP (e.g., pressure, time and temperature) and AITC. With the addition of AITC, the hydrostatic pressure may be lowered to the 250–350 MPa level. Regulatory agencies and food industry may use those models for STEC risk assessment in ground chicken meat. A storage test (at 4 and 10°C, 10 days) after HPP+AITC treatment indicated that AITC may continue depressing or killing the pressure-damaged cells.

Protective Effects of 6-(Methylsulfinyl)hexyl Isothiocyanate on Aβ1-42-Induced Cognitive Deficit, Oxidative Stress, Inflammation, and Apoptosis in Mice

Alzheimer's disease (AD) is the most common form of dementia among older people. Although soluble amyloid species are recognized triggers of the disease, no therapeutic approach is able to stop it. 6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC) is a major bioactive compound in Wasabia japonica, which is a typical Japanese pungent spice. Recently, in vivo and in vitro studies demonstrated that 6-MSITC has several biological properties. The aim of the present study was to investigate the neuroprotective activity of 6-MSITC in a murine AD model, induced by intracerebroventricular injection of β-amyloid oligomers (Aβ1-42O). The treatment with 6-MSITC started 1 h after the surgery for the next 10 days. Behavioral analysis showed that 6-MSITC ameliorated Aβ1-42O-induced memory impairments. The decrease of glutathione levels and increase of reactive oxygen species in hippocampal tissues following Aβ1-42O injection were reduced by 6-MSITC. Moreover, activation of caspases, increase of inflammatory factors, and phosphorylation of ERK and GSK3 were inhibited by 6-MSITC. These results highlighted an interesting neuroprotective activity of 6-MSITC, which was able to restore a physiological oxidative status, interfere positively with Nrf2-pathway, decrease apoptosis and neuroinflammation and contribute to behavioral recovery. Taken together, these findings demonstrated that 6-MSITC could be a promising complement for AD therapy.

Isothiocyanates: An Overview of Their Antimicrobial Activity against Human Infections

The use of plant-derived products as antimicrobial agents has been investigated in depth. Isothiocyanates (ITCs) are bioactive products resulting from enzymatic hydrolysis of glucosinolates (GLs), the most abundant secondary metabolites in the botanical order Brassicales. Although the antimicrobial activity of ITCs against foodborne and plant pathogens has been well documented, little is known about their antimicrobial properties against human pathogens. This review collects studies that focus on this topic. Particular focus will be put on ITCs’ antimicrobial properties and their mechanism of action against human pathogens for which the current therapeutic solutions are deficient and therefore of prime importance for public health. Our purpose was the evaluation of the potential use of ITCs to replace or support the common antibiotics. Even though ITCs appear to be effective against the most important human pathogens, including bacteria with resistant phenotypes, the majority of the studies did not show comparable results and thus it is very difficult to compare the antimicrobial activity of the different ITCs. For this reason, a standard method should be used and further studies are needed.

The therapeutic efficacy of allyl isothiocyanate in cows with bovine digital dermatitis

Bovine digital dermatitis (BDD) is the most prevalent infectious cause of lameness in cattle. Because Treponema infection is a major etiology of BDD, the most common treatment of BDD is an antibiotic. Nonetheless, dairy cows require a withdrawal period after antibiotic treatment before their milk can be marketed. To address the problem, in this study, we tested whether 3 nonantibiotic agents (used separately)—allyl isothiocyanate (AITC), sodium alginate, and calcium hydroxide—alleviate BDD lesions in dairy cows. The AITC treatment improved the BDD lesions, whereas the sodium alginate and calcium hydroxide treatments did not. Therapeutic efficacy of AITC was similar to that of lincomycin, a topical antibiotic prescribed for BDD. These results suggest that AITC is a promising nonantibiotic agent for BDD treatment in dairy cows.

Improvement Effects of Wasabi (Wasabia japonica) Leaves and Allyl Isothiocyanate on Stomach Lesions of Mongolian Gerbils Infected with Helicobacter pylori

The relationship between Helicobacter pylori infection and gastric cancer associated with stomach lesions has been reported. Improvement of the adverse effects induced by H. pylori is required for human health. It has been reported that wasabi ( Wasabia japonica Matsum) leaves have various effects on bacteria and mammals. In this study, the effect was examined of wasabi leaf extract and allyl isothiocyanate (AIT), which is a main functional component of wasabi, on stomach lesions in Mongolian gerbils infected with H. pylori. After the gerbils infected with H. pylori were orally administrated with wasabi leaf extract and AIT for two weeks, colony forming units (CFU) of H. pylori, the degree of gastric mucosal erosion, and petechial hemorrhage in the stomachs of the gerbils were evaluated. Wasabi leaf extract and AIT exhibited a decreasing tendency of CFU in the stomachs. The degree of gastric mucosal erosion and petechial hemorrhage were significantly decreased by the intake of wasabi leaf extract and AIT. Wasabi leaf extract and AIT did not affect body weight, dietary intake, water intake, and the pH of the stomach. From these results, wasabi leaves and AIT may provide a natural remedy for stomach lesions induced by H. pylori.