Allyl Isothiocyanate Research Articles

Eukaryotic Expression of the Cytochrome c Oxidase Subunit I of Sitophilus zeamais and Its Interaction with Allyl Isothiocyanate.

Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) is a destructive pest of stored grains around the world. Allyl isothiocyanate (AITC) was shown to have good bioactivity in the control of S. zeamais. In this study, the interaction of AITC on cytochrome c oxidase core subunits I (COX I) and their binding mechanism were determined using spectroscopic, isothermal titration calorimetry and molecular docking techniques. The results indicate the binding constant (Ka) of AITC and COX I was 6.742 × 103 L/mol. Analysis of spectroscopic revealed that the binding of COX I to reduced Cyt c induced conformational changes of reduced Cyt c, while AITC could competitively bind and inhibit the activity of the COX I protein. Moreover, molecular docking results suggested a sulfur atom in the AITC structure could form a hydrogen bond having a length of 3.3 Å with the Gly- 27 of COX I.

Antimicrobial Compounds in Food Packaging.

This review presents current knowledge on antimicrobial agents that are already used in the food packaging industry. At the beginning, innovative ways of food packaging were discussed, including how smart packaging differs from active packaging, and what functions they perform. Next, the focus was on one of the groups of bioactive components that are used in these packaging, namely antimicrobial agents. Among the antimicrobial agents, we selected those that have already been used in packaging and that promise to be used elsewhere, e.g., in the production of antimicrobial biomaterials. Main groups of antimicrobial agents (i.e., metals and metal oxides, organic acids, antimicrobial peptides and bacteriocins, antimicrobial agents of plant origin, enzymes, lactoferrin, chitosan, allyl isothiocyanate, the reuterin system and bacteriophages) that are incorporated or combined with various types of packaging materials to extend the shelf life of food are described. The further development of perspectives and setting of new research directions were also presented.

Bipartite Activation of Sensory Neurons by a TRPA1 Agonist Allyl Isothiocyanate Is Reflected by Complex Ca2+ Influx and CGRP Release Patterns: Enhancement by NGF and Inhibition with VAMP and SNAP-25 Cleaving Botulinum Neurotoxins.

The trafficking of transient receptor potential (TRP) channels to the plasma membrane and the release of calcitonin gene-related peptide (CGRP) from trigeminal ganglion neurons (TGNs) are implicated in some aspects of chronic migraines. These exocytotic processes are inhibited by cleavage of SNAREs with botulinum neurotoxins (BoNTs); moreover, type A toxin (/A) clinically reduces the frequency and severity of migraine attacks but not in all patients for unknown reasons. Herein, neonatal rat TGNs were stimulated with allyl isothiocyanate (AITC), a TRPA1 agonist, and dose relationships were established to link the resultant exocytosis of CGRP with Ca2+ influx. The CGRP release, quantified by ELISA, was best fit by a two-site model (EC50 of 6 and 93 µM) that correlates with elevations in intracellular Ca2+ [Ca2+]i revealed by time-lapse confocal microscopy of fluo-4-acetoxymethyl ester (Fluo-4 AM) loaded cells. These signals were all blocked by two TRPA1 antagonists, HC-030031 and A967079. At low [AITC], [Ca2+]i was limited because of desensitisation to the agonist but rose for concentrations > 0.1 mM due to a deduced non-desensitising second phase of Ca2+ influx. A recombinant BoNT chimera (/DA), which cleaves VAMP1/2/3, inhibited AITC-elicited CGRP release to a greater extent than SNAP-25-cleaving BoNT/A. /DA also proved more efficacious against CGRP efflux evoked by a TRPV1 agonist, capsaicin. Nerve growth factor (NGF), a pain-inducing sensitiser of TGNs, enhanced the CGRP exocytosis induced by low [AITC] only. Both toxins blocked NGF-induced neuropeptide secretion and its enhancement of the response to AITC. In conclusion, NGF sensitisation of sensory neurons involves TRPA1, elevated Ca2+ influx, and CGRP exocytosis, mediated by VAMP1/2/3 and SNAP-25 which can be attenuated by the BoNTs.

Biochemical and Structural Insights into FIH-Catalysed Hydroxylation of Transient Receptor Potential Ankyrin Repeat Domains.

Transient receptor potential (TRP) channels have important roles in environmental sensing in animals. Human TRP subfamily A member 1 (TRPA1) is responsible for sensing allyl isothiocyanate (AITC) and other electrophilic sensory irritants. TRP subfamily vanilloid member 3 (TRPV3) is involved in skin maintenance. TRPV3 is a reported substrate of the 2-oxoglutarate oxygenase factor inhibiting hypoxia-inducible factor (FIH). We report biochemical and structural studies concerning asparaginyl hydroxylation of the ankyrin repeat domains (ARDs) of TRPA1 and TRPV3 catalysed by FIH. The results with ARD peptides support a previous report on FIH-catalysed TRPV3 hydroxylation and show that, of the 12 potential TRPA1 sequences investigated, one sequence (TRPA1 residues 322-348) undergoes hydroxylation at Asn336. Structural studies reveal that the TRPA1 and TRPV3 ARDs bind to FIH with a similar overall geometry to most other reported FIH substrates. However, the binding mode of TRPV3 to FIH is distinct from that of other substrates.

Non-neuronal TRPA1 encodes mechanical allodynia associated with neurogenic inflammation and partial nerve injury in rats.

The pro-algesic transient receptor potential ankyrin 1 (TRPA1) channel, expressed by a subpopulation of primary sensory neurons, has been implicated in various pain models in mice. However, evidence in rats indicates that TRPA1 conveys nociceptive signals elicited by channel activators, but not those associated with tissue inflammation or nerve injury. Here, in rats, we explored the TRPA1 role in mechanical allodynia associated with stimulation of peptidergic primary sensory neurons (neurogenic inflammation) and moderate (partial sciatic nerve ligation, pSNL) or severe (chronic constriction injury, CCI) sciatic nerve injury. Acute nociception and mechanical hypersensitivity associated with neurogenic inflammation and sciatic nerve injury (pSNL and CCI) were investigated in rats with TRPA1 pharmacological antagonism or genetic silencing. TRPA1 presence and function were analysed in cultured rat Schwann cells. Hind paw mechanical allodynia (HPMA), but not acute nociception, evoked by local injection of capsaicin or allyl isothiocyanate, the TRP vanilloid 1 (TRPV1) or the TRPA1 activators was mediated by CGRP released from peripheral sensory nerve terminals. CGRP-evoked HPMA was sustained by a ROS-dependent TRPA1 activation, probably in Schwann cells. HPMA evoked by pSNL, but not that evoked by CCI, was mediated by ROS and TRPA1 without the involvement of CGRP. As found in mice, TRPA1 mediates mechanical allodynia associated with neurogenic inflammation and moderate nerve injury in rats. The channel contribution to mechanical hypersensitivity is a common feature in rodents and might be explored in humans.

Irritant-evoked reflex tachyarrhythmia in spontaneously hypertensive rats is reduced by inhalation of TRPM8 agonists l-menthol and WS-12.

Inhalation of noxious irritants activates nociceptive sensory afferent nerves innervating the airways, inducing reflex regulation of autonomic networks and the modulation of respiratory drive and cardiovascular (CV) parameters such as heart rate and blood pressure. In healthy mammals, irritant-evoked pulmonary-cardiac reflexes cause parasympathetic-mediated bradycardia. However, in spontaneously hypertensive (SH) rats, irritant inhalation also increases sympathetic drive to the heart. This remodeled pulmonary-cardiac reflex may contribute to cardiovascular risk caused by inhalation of air pollutants/irritants in susceptible individuals with cardiovascular disease (CVD). Previous studies have shown that the cooling mimic l-menthol, an agonist for the cold-sensitive transient receptor potential melastatin 8 (TRPM8), can alleviate nasal inflammatory symptoms and respiratory reflexes evoked by irritants. Here, we investigated the impact of inhalation of TRPM8 agonists l-menthol and WS-12 on pulmonary-cardiac reflexes evoked by inhalation of the irritant allyl isothiocyanate (AITC) using radiotelemetry. l-Menthol, but not its inactive analog d-menthol, significantly reduced the AITC-evoked reflex tachycardia and premature ventricular contractions (PVCs) in SH rats but had no effect on the AITC-evoked bradycardia in either SH or normotensive Wistar-Kyoto (WKY) rats. WS-12 reduced AITC-evoked tachycardia and PVCs in SH rats, but this more potent TRPM8 agonist also reduced AITC-evoked bradycardia. l-Menthol had no effect on heart rate when given alone, whereas WS-12 evoked a minor bradycardia in WKY rats. We conclude that stimulation of TRPM8-expressing afferents within the airways reduces irritant-evoked pulmonary-cardiac reflexes, especially the aberrant reflex tachyarrhythmia in SH rats. Airway menthol treatment may be an effective therapy for reducing pollution-associated CV exacerbations.NEW & NOTEWORTHY Irritant-evoked pulmonary-cardiac reflexes are remodeled in spontaneously hypertensive (SH) rats-causing de novo sympathetic reflexes that drive tachyarrhythmia. This remodeling may contribute to air pollution-associated risk in susceptible individuals with cardiovascular disease. We found that inhalation of TRPM8 agonists, l-menthol and WS-12, but not the inactive analog d-menthol, selectively reduces the reflex tachyarrhythmia evoked by allyl isothiocyanate (AITC) inhalation in SH rats. Use of menthol may protect susceptible individuals from pollution-associated CV exacerbations.

Allyl isothiocyanate and 6-(methylsulfinyl) hexyl isothiocyanate contents vary among wild and cultivated wasabi (Eutrema japonium).

Wasabi (Japanese horseradish, Eutrema japonicum) is the only cultivated species in the genus Eutrema with functional components that provide a strong pungent flavor. To evaluate genetic resources for wasabi breeding, we surveyed variations in the two most abundant isothiocyanate (ITC) components in wasabi, allyl isothiocyanate (AITC) and 6-methylsulfinyl (hexyl) isothiocyanate (6-MSITC, hexaraphane). We also examined the phylogenetic relationships among 36 accessions of wild and cultivated wasabi in Japan using chloroplast DNA analysis. Our results showed that (i) the 6-MSITC content in currently cultivated wasabi accessions was significantly higher than in escaped cultivars, whereas the AITC content was not significantly different. (ii) Additionally, the 6-MSITC content in cultivated wasabi was significantly lower in the spring than during other seasons. This result suggested that the 6-MSITC content responds to environmental conditions. (iii) The phylogenetic position and the 6-MSITC content of accessions from Rebun, Hokkaido Prefecture had different profiles compared with those from southern Honshu, Japan, indicating heterogeneity of the Rebun populations from other Japanese wasabi accessions. (iv) The total content of AITC and 6-MSITC in cultivated wasabi was significantly higher than that of wild wasabi. In conclusion, old cultivars or landraces of wasabi, "zairai", are the most suitable candidates for immediate use as genetic resources.

Natural Sulfur Compounds, Allyl Isothiocyanate and Diallyl Disulfide, Promote Cis to Trans Isomerization of Fatty Acid Esters during Heat Treatment.

The effects of allyl isothiocyanate (AITC) and diallyl disulfide (DADS), widely found in edible vegetables, on thermal isomerization of unsaturated fatty acid esters (oleic acid methyl ester [OA-ME], linoleic acid methyl ester [LA-ME], and eicosapentaenoic acid ethyl ester [EPA-EE]) were investigated. Although heating with AITC and DADS significantly promoted cis to trans isomerization of all fatty acid esters, the isomerization trends varied greatly depending on the type of fatty acid. Specifically, AITC promoted thermal isomerization of OA-ME and LA-ME more efficiently than DADS; however, an opposite result was obtained for EPA-EE. For example, when OA-ME was heated at 180°C for 1 h with 1.0 equivalent of AITC and DADS, its trans isomer ratios reached 29.0 ± 7.1 and 7.6 ± 0.6%, respectively, and when EPA-EE was heated under the same conditions, its trans isomer ratios reached 4.2 ± 0.4 and 8.6 ± 0.2%, respectively. These results indicate that isothiocyanates and polysulfides would promote the formation of trans fatty acids in food processing under heating conditions.

Allyl isothiocyanate dry powder inhaler based on cyclodextrin-metal organic frameworks for pulmonary delivery

In this study, allyl isothiocyanate (AITC) was prepared as the dry powder inhalation by loading cyclodextrin metal-organic framework (CD-MOF) to enhance pulmonary delivery. β-CD-MOF and γ-CD-MOF both could be used to carry AITC with the optimal loading conditions (50˚C, n CD: n AITC= 1:7, 7h). Compared with β-CD-MOF, γ-CD-MOF had more advantages in AITC loading due to its high drug loading and stable crystal morphology. The particle size and the mass median aerodynamic diameter of γ-CD-MOF-AITC were accorded with the aerodynamic characteristics of lung inhalation. γ-CD-MOF-AITC might be deposited effectively in the deep lung, and the release rate of AITC reached over 90% within 5min. Meanwhile, it had good pulmonary local tolerance, permeability, and no significant toxicity. Such results indicated that γ-CD-MOF could be used as a dry powder inhaler carrier to deliver safely AITC to lung and increase its pulmonary absorption.

Water extract of Notopterygium incisum alleviates cold allodynia in neuropathic pain by regulation of TRPA1

Ethnopharmacological relevanceNeuropathic pain can be debilitating and drastically affects the quality of life of those patients suffering from this condition. The Chinese herb Notopterygium incisum Ting ex H.T. Chang has long been used to disperse “cold”. One under examined clinical feature of neuropathic pain is sensitivity to cold. Patients with neuropathic pain or arthritis usually describe a worsening of symptoms during the winter. Aims of this studyWe proposed to test the hypothesis that Notopterygium incisum has a positive effect on the cold sensitivity found in neuropathic pain. Materials and methodsIn this study, we established chronic constriction injury (CCI) and cisplatin induced neuropathic pain mice models. Behavioral experiments and physiological examination methods were employed to investigate the effect of water extract of Notopterygium incisum (WN) on cold pain. ResultsWe found WN reduced cold pain and allyl isothiocyanate (AITC, Transient Receptor Potential A1 (TRPA1 agonist)) induced pain. WN inhibited AITC induced calcium response in HEK 293 cells transfected with TRPA1 and dorsal root ganglion (DRG) neurons. Moreover, we found that oral administration of WN reduced cold allodynia and mechanical allodynia caused by (CCI) and cisplatin induced neuropathic pain. We also observed that oral administration of WN decreased responses to AITC in DRG neurons as well as expression of TRPA1 in the WN treated neuropathic pain model. ConclusionsThe present study provide evidence that Notopterygium incisum alleviates cold allodynia in CCI and cisplatin induced neuropathic pain mouse models. WN alleviated neuropathic pain induced cold allodynia via directly modulating TRPA1. Our findings identify WN as a promising candidate for treating neuropathic pain that highlights a new mechanism of Notopterygium incisum on ‘disperse cold’.

Effect of a carrageenan/chitosan coating with allyl isothiocyanate on microbial spoilage and quality of chicken breast

Approximately 3.7% of poultry meat is lost due to spoilage each year in the United States. The objective of this study was to determine the efficacy of a layered carrageenan/chitosan coating in combination with an application of two concentrations of allyl isothiocyanate (AITC) against lactic acid bacteria, aerobic bacteria, and yeast and mold during storage of chicken breast for 21 d. Additionally, the rancidity, color, and pH of the chicken breast as indicators of non-microbial quality were evaluated. The combination of carrageenan/chitosan coating with 20 and 200 ppm AITC reduced (P ≤ 0.05) yeast and mold populations by 3 log10 CFU/g at d 21 compared to the untreated control. The carrageenan/chitosan coating with 20 and 200 ppm AITC delayed aerobic spoilage by 3 and 12 d, respectively, compared to the untreated control; aerobic bacteria populations on the samples treated with 200 ppm AITC remained below the threshold for spoilage (∼6 log10 CFU/g) for the duration of storage. The pH of the 20 ppm and 200 ppm AITC-treated chicken breast was unaltered (P > 0.05) at the end of storage and was lower than the pH of the untreated and coating-only-treated control chicken breast at d 18 through the end of storage (P ≤ 0.05). The application of the coating alone did not (P > 0.05) affect L*, a*, and b* values of the chicken breast at the end of storage compared to the uncoated control. The carrageenan/chitosan coating with 20 and 200 ppm AITC prevented decreases in the lightness (L* values) of the chicken breast at the end of storage (P ≤ 0.05) compared to the control and coating-only-treated samples. The coating alone or with AITC did not (P > 0.05) impact the rancidity of the chicken breast over the 21-d storage period, thus showing potential to be used as antimicrobial packaging to increase shelf life of fresh poultry.

The antimalarial artemisinin is a non-electrophilic agonist of the transient receptor potential ankyrin type 1 receptor-channel

Artemisinin and its derivatives are the main therapeutic drugs against Plasmodium protists, the causative agents of malaria. While several putative mechanisms of action have been proposed, the precise molecular targets of these compounds have not been fully elucidated. In addition to their antimalarial properties, artemisinins have been reported to act as anti-tumour agents and certain antinociceptive effects have also been proposed. We investigated the effect of the parent compound, artemisinin, on a number of temperature-gated Transient Receptor Potential ion channels (so called thermoTRPs), given their demonstrated roles in pain-sensing and cancer. We report that artemisinin acts as an agonist of the Transient Receptor Potential Ankyrin type 1 (TRPA1) receptor channel. Artemisinin was able to evoke calcium transients in HEK293T cells expressing recombinant human TRPA1, as well as in a subpopulation of mouse dorsal root ganglion (DRG) neurons which also responded to the selective TRPA1 agonist allyl isothiocyanate (AITC) and these responses were reversibly abolished by the selective TRPA1 antagonist A967079. Artemisinin also triggered whole-cell currents in HEK293T cells transiently transfected with human TRPA1, as well as in TRPA1-expressing DRG neurons, and these currents were inhibited by A967079. Interestingly, using human TRPA1 mutants, we demonstrate that artemisinin acts as a non-electrophilic agonist of TRPA1, activating the channel in a similar manner to carvacrol and menthol. These results may provide a better understanding of the biological actions of the very important antimalarial and anti-tumour agent artemisinin.

Potent Activation of Human but Not Mouse TRPA1 by JT010.

Transient receptor potential (TRP) ankyrin repeat 1 (TRPA1), which is involved in inflammatory pain sensation, is activated by endogenous factors, such as intracellular Zn2+ and hydrogen peroxide, and by irritant chemical compounds. The synthetic compound JT010 potently and selectively activates human TRPA1 (hTRPA1) among the TRPs. Therefore, JT010 is a useful tool for analyzing TRPA1 functions in biological systems. Here, we show that JT010 is a potent activator of hTRPA1, but not mouse TRPA1 (mTRPA1) in human embryonic kidney (HEK) cells expressing hTRPA1 and mTRPA1. Application of 0.3-100 nM of JT010 to HEK cells with hTRPA1 induced large Ca2+ responses. However, in HEK cells with mTRPA1, the response was small. In contrast, both TRPA1s were effectively activated by allyl isothiocyanate (AITC) at 10-100 μM. Similar selective activation of hTRPA1 by JT010 was observed in electrophysiological experiments. Additionally, JT010 activated TRPA1 in human fibroblast-like synoviocytes with inflammation, but not TRPA1 in mouse dorsal root ganglion cells. As cysteine at 621 (C621) of hTRPA1, a critical cysteine for interaction with JT010, is conserved in mTRPA1, we applied JT010 to HEK cells with mutations in mTRPA1, where the different residue of mTRPA1 with tyrosine at 60 (Y60), with histidine at 1023 (H1023), and with asparagine at 1027 (N1027) were substituted with cysteine in hTRPA1. However, these mutants showed low sensitivity to JT010. In contrast, the mutation of hTRPA1 at position 669 from phenylalanine to methionine (F669M), comprising methionine at 670 in mTRPA1 (M670), significantly reduced the response to JT010. Moreover, the double mutant at S669 and M670 of mTRPA1 to S669E and M670F, respectively, induced slight but substantial sensitivity to 30 and 100 nM JT010. Taken together, our findings demonstrate that JT010 potently and selectively activates hTRPA1 but not mTRPA1.

Weed suppression and antioxidant activity of Astragalus sinicus L. decomposition leachates.

Astragalus sinicus L. (milk vetch), a versatile plant that has a soil-enriching effect as green manure, is widely planted in the temperate zone of China. In previous experiments, milk vetch incorporated into the soil as green manure showed potential for goosegrass control. However, "what exactly happens at the chemical level?" and "what are the compounds that are potentially responsible for the phytotoxic effects observed during those previous assays?" In a recent study, in vitro phytotoxicity bioassays and chemical analyses of milk vetch decomposition leachates were carried out to explore the relationship between the temporal phytotoxic effects and the dynamics of chemical composition. For that, milk vetch decomposition leachates with a decay time of 12h, 9 days, 12 days, 15 days, and 18 days were analyzed for organic compounds by liquid chromatography. The main results were as follows: (1) three compounds with goosegrass suppression potential produced during the decomposed process, i.e., 4-ethylphenol, N-acrylimorpholine, and allyl isothiocyanate. 2-Hydroxyethyl acrylate was present in the 12-h decomposition leachates but was at its highest concentration of 127.1 µg ml-1 at 15 days. (2) The cultures were configured according to the four concentrations of goosegrass-resistant active substances measured in the 15-day decomposition leachate and, as with the 15-day decomposition leachate, the mixture cultures inhibited 100% of goosegrass germination at the high concentrations (≥ 30%), which suggests that these substances have goosegrass suppression potential. (3) The high total phenolic content (302.8-532.3 mg L-1), the total flavonoid content (8.4-72.1 mg L-1), and the reducing activity of the decomposition leachates for different decay times may explain why the incorporation of milk vetch into the soil did not lead to peroxidation of goosegrass in the previous study. (4) Finally, the changes in acid fraction and total content (1.9-4.2 mg ml-1) for different decay times explain the variations in pH of the decomposition leachates, which, when discussed in conjunction with previous studies, may lead to changes in soil nutrient effectiveness and consequently affect crop growth. This study can provide a reference for green weed control research.

An Inhibitory Function of TRPA1 Channels in TGF-β1-driven Fibroblast-to-Myofibroblast Differentiation.

TRPA1 (transient receptor potential ankyrin 1) is a nonselective Ca2+-permeable cation channel, which was originally cloned from human lung fibroblasts (HLFs). TRPA1-mediated Ca2+ entry is evoked by exposure to several chemicals, including allyl isothiocyanate (AITC), and a protective effect of TRPA1 activation in the development of cardiac fibrosis has been proposed. Yet the function of TRPA1 in TGF-β1 (transforming growth factor-β1)-driven fibroblast-to-myofibroblast differentiation and the development of pulmonary fibrosis remains elusive. TRPA1 expression and function were analyzed in cultured primary HLFs, and mRNA concentrations were significantly reduced after adding TGF-β1. Expression of genes encoding fibrosis markers (e.g., ACTA2, SERPINE1 [plasminogen activator inhibitor 1], FN1 [fibronectin], COL1A1 [type I collagen]) was increased after siRNA-mediated downregulation of TRPA1 mRNA in HLFs. Moreover, AITC-induced Ca2+ entry in HLFs was decreased after TGF-β1 treatment and by application of TRPA1 siRNAs, while AITC treatment alone did not reduce cell viability or enhance apoptosis. Most interestingly, AITC-induced TRPA1 activation augmented ERK1/2 (extracellular signal-regulated kinase 1/2) and SMAD2 linker phosphorylation, which might inhibit TGF-β-receptor signaling. Our results suggest an inhibitory function of TRPA1 channels in TGF-β1-driven fibroblast-to-myofibroblast differentiation. Therefore, activation of TRPA1 channels might be protective during the development of pulmonary fibrosis in patients.

Isothiocyanate-Rich Extracts from Cauliflower (Brassica oleracea Var. Botrytis) and Radish (Raphanus sativus) Inhibited Metabolic Activity and Induced ROS in Selected Human HCT116 and HT-29 Colorectal Cancer Cells

Cruciferous vegetables such as cauliflower and radish contain isothiocyanates exhibiting chemoprotective effects in vitro and in vivo. This research aimed to assess the impact of cauliflower (CIE) and radish (RIE) isothiocyanate extracts on the metabolic activity, intracellular reactive oxygen species (ROS), and LDH production of selected human colorectal adenocarcinoma cells (HCT116 and HT-29 for early and late colon cancer development, respectively). Non-cancerous colon cells (CCD-33Co) were used as a cytotoxicity control. The CIE samples displayed the highest allyl isothiocyanate (AITC: 12.55 µg/g) contents, whereas RIE was the most abundant in benzyl isothiocyanate (BITC: 15.35 µg/g). Both extracts effectively inhibited HCT116 and HT-29 metabolic activity, but the CIE impact was higher than that of RIE on HCT116 (IC50: 0.56 mg/mL). Assays using the half-inhibitory concentrations (IC50) of all treatments, including AITC and BITC, displayed increased (p < 0.05) LDH (absorbance: 0.25-0.40 nm) and ROS release (1190-1697 relative fluorescence units) in both cell lines. BITC showed the highest in silico binding affinity with all the tested colorectal cancer molecular markers (NF-kB, β-catenin, and NRF2-NFE2). The theoretical evaluation of AITC and BITC bioavailability showed high values for both compounds. The results indicate that CIE and RIE extracts display chemopreventive effects in vitro, but additional experiments are needed to validate their effects.

Glucosinolate-derived amine formation in Brassica oleracea vegetables

Glucosinolates are precursors of bioactive and health-promoting isothiocyanates (ITCs). Upon enzymatic hydrolysis, Brassica vegetables, such as cabbage, also often yield nitriles and epithionitriles as main products next to ITCs. Here, we show that amines can be additional main enzymatic hydrolysis products of glucosinolates in Brassica vegetables. We propose that a plant endogenous ITC hydrolase (ITCase) is responsible for the enzymatic-like conversion of ITCs to amines in cabbage samples. This ITCase seems to have high activity towards alkenyl ITCs like allyl ITC and lower activity towards methylthioalkyl ITCs, and not to converting methylsulfinylalkyl ITCs like sulforaphane. In contrast, during heat treatment of homogenized cabbage material, methylsulfinylalkylamine levels increased by 400 % after 2 h of heating, which is likely due to thermal decomposition of ITCs, whereas alkenyl amine levels did not change due to heat treatment. The results show that amines from glucosinolates are part of the human diet.

Effects of Four Isothiocyanates in Dissolved and Gaseous States on the Growth and Aflatoxin Production of Aspergillus flavus In Vitro.

Aflatoxins (AFs), a class of toxins produced by certain species of the genus Aspergillus, occasionally contaminate food and cause serious damage to human health and the economy. AFs contamination is a global problem, and there is a need to develop effective strategies to control aflatoxigenic fungi. In this study, we focused on isothiocyanates (ITCs) as potential chemical agents for the control of aflatoxigenic fungi. We quantitatively evaluated the effects of four ITCs (allyl ITC (AITC), benzyl ITC (BITC), and methyl and phenylethyl ITCs) in dissolved and gaseous states on the growth and aflatoxin B1 production of Aspergillus flavus. In experiments using dissolved ITCs, BITC was found to be the strongest inhibitor of growth and aflatoxin B1 production by A. flavus. Meanwhile, in the gaseous state, AITC strongly inhibited the A. flavus growth. When the concentration of ITCs in the liquid medium was quantified over time, AITC levels decreased to below the detection limit within 24 h, whereas BITC levels remained stable even after 48 h. These results suggested that when ITCs are utilized to control aflatoxigenic fungi, it is necessary to use them in a dissolved or gaseous state, depending on their volatility.

Synergistic effect of high hydrostatic pressure, allyl isothiocyanate, and acetic acid on the inactivation and survival of pathogenic Escherichia coli in ground chicken.

Meat and poultry are prone to contamination with foodborne pathogens sourced from the livestock or introduced from the processing environments. In this study, for retention of meat quality while assuring microbial food safety, mild levels of high hydrostatic pressure were hurdled with food-grade additives (i.e., allyl isothiocyanate [AITC] and acetic acid [AA], functioned as antimicrobials) to inactivate pathogenic Escherichia coli in ground chicken. The reductions of Shiga toxin-producing E. coli (STEC) O157:H7 and uropathogenic E. coli (UPEC) were described as a function of high hydrostatic pressure (200-350MPa), process-holding time (10-25 min), AITC concentration (0.05-0.20% w/w), and AA concentration (0.10--0.30% w/w) using a full factorial design. The antimicrobials had little influence on bacterial inactivation without high pressure. Without the antimicrobials, a high-pressure treatment at 300MPa and 4°C for 15 min reduced E. coli O157:H7 and UPEC by 1.52 and 2.52 log, respectively. A 5-log reduction was achieved when AITC and AA were combined with high pressure, indicating a synergistic effect. The survivors were further reduced to below the detection limit of 1 log CFU/g after subsequent storage tests at 4 and 10°C for 10 days. The STEC O157:H7 was found slightly more resistant than UPEC in our test matrix. The developed models showed good fits with experimental data (R2 >0.95 for linear models; Pr>F(<0.0001) for dimensionless nonlinear models); which may help processors find/optimize the processing parameters to achieve target foodborne pathogens reduction for food safety requirement. PRACTICAL APPLICATION: Models were developed to predict the inactivation of pathogenic Escherichia coli in ground chicken by high-pressure processing (HPP) in combination with natural antimicrobial compounds. These models can be used to estimate/determine the HPP operation parameters and antimicrobial usage levels (i.e., allyl isothiocyanate and acetic acid) needed to achieve a specific microbial log reduction within the selected factor ranges. The operation parameters and clean-label ingredients are of interest in the food industry, which may benefit from the application of the models in achieving microbial safety, process optimization, and operation cost reduction.

Copper-Catalyzed Multicomponent Reactions of Intramolecular and Intermolecular Thiotrifluoromethylation of Alkenes: Access to CF3-Containing 2-Iminothiazolidines and Isothioureas.

A copper-catalyzed multicomponent reaction of secondary amines bearing allyl substitution, isothiocyanates, and Togni reagent II has been developed under Cs2CO3 in DCE at 75 °C. An intermolecular multicomponent reaction of thioureas, activated and unactivated alkenes, and Togni reagent II has also been developed under DMAP in acetonitrile at room temperature. These two alkene difunctionalization reactions provide CF3-containing 2-iminothiazolindines and isothioureas in moderate to excellent yields with broad substrate scope and good functional group tolerance, respectively.