Indole Glucosinolates Research Articles

Effect of sodium selenite on the synthesis of glucosinolates and antioxidant capacity in Chinese cabbage (Brassica rapa L.ssp.pekinensis).

Chinese cabbage (Brassica rapa ssp. pekinensis) is a globally cultivated and consumed leafy vegetable due to its abundant plant secondary metabolites and antioxidant compounds, including flavonoids, ascorbic acids, glucosinolates, and vitamins, which have been reported to confer health-promoting effects. Glucosinolates components in leaves of Chinese cabbage plantlets under different concentrations of sodium selenite (0, 30, and 50μmol/L) were analyzed. Seven glucosinolates were identified and quantified using UHPLC-QTOF-MS. Finally, treatments with 30 and 50μmol/L Na2SeO3 solution significantly increased the levels of total selenium content as well as total phenols, flavonoids, anthocyanins, and DPPH free radical scavenging ability in Chinese cabbage seedlings. Our results revealed that 30μmol/L Na2SeO3 effectively enhanced aliphatic glucosinolate levels and total glucosinolate content while causing a significant reduction in indole glucosinolates. Furthermore, downregulation was observed for BrCYP79F1, BrBCAT4, and BrMAM1 genes associated with aliphatic glucosinolate synthesis. Conversely, BrMYB28 and BrCYP83A1 genes exhibited significant upregulation. Thus, the positive influence of Na2SeO3 on glucosinolate biosynthesis in Chinese cabbage can be attributed to the upregulation of key genes related to this process.

Enhancing the formation of functional glucosinolate degradation products in fermented broccoli stalk by-product with lactic acid bacteria

Broccoli stalk by-product (BsBP) is rich in glucosinolates (GSLs). Its fermentation process is generally characterized by the degradation of GSLs and formation of bioactive isothiocyanates (ITCs), in which lactic acid bacteria (LAB) play an important role. The GSLs-degrading capacity of 61 LAB strains was investigated in vitro. Lacticaseibacillus paracasei YC5, Pediococcus pentosaceus RBHZ36, and Lactiplantibacillus plantarum ND1, with high potential to transform GSLs into ITCs, were screened. The functional GSL degradation products (total content of sulforaphane, indol-3-carbinol, and ascorbigen) increased 22.0–33.5 % compared to natural fermentation after 24 h when BsBP was fermented by the three screened strains in pure culture. LAB fermentation also helped to increase the quantity of indolic GSL degradation products in BsBP brine, suggesting that LAB fermentation promoted BsBP GSLs transformation into bioactive ITCs. The proposed use of the LAB strains characterized in this study provided a fermented BsBP and brine with high profile of functional GSL degradation products.

Mitogen-activated protein kinase-mediated regulation of plant specialized metabolism

Abstract Post-transcriptional and post-translational modification of transcription factors (TFs) and pathway enzymes significantly affect the stress-stimulated biosynthesis of specialized metabolites (SMs). Protein phosphorylation is one of the conserved and ancient mechanisms that critically influences many biological processes including specialized metabolism. The phosphorylation of TFs and enzymes by protein kinases (PKs), especially the mitogen-activated protein kinases (MAPKs), is well studied in plants. While the roles of MAPKs in plant growth and development, phytohormone signaling, and immunity are well elucidated, significant recent advances have also been made in understanding the involvement of MAPKs in specialized metabolism. However, a comprehensive review highlighting the significant progress in the past several years is notably missing. This review focuses on MAPK-mediated regulation of several important SMs, including phenylpropanoids (flavonoids and lignin), terpenoids (artemisinin and other terpenoids), alkaloids (terpenoid indole alkaloids and nicotine), and other nitrogen- and sulfur-containing SMs (camalexin and indole glucosinolates). In addition to MAPKs, other PKs also regulate SM biosynthesis. For comparison, we briefly discuss the regulation by other PKs, such as sucrose non-fermenting-1 (SNF)-related protein kinases (SnRKs) and calcium-dependent protein kinases (CPKs). Furthermore, we provide future perspectives in this active area of research.

An EIL Family Transcription Factor From Switchgrass Affects Sulphur Assimilation and Root Development in Arabidopsis.

Sulphur limitation 1 (SLIM1), a member of ethylene-insensitive3-like (EIN3/EIL) protein family, is recognised as the pivotal transcription factor regulating sulphur assimilation, essential for maintaining sulphur homoeostasis in Arabidopsis. However, the function of its monocot homologues is largely unknown. In this study, we identified PvEIL3a, a homologous gene of AtSLIM1, from switchgrass (Panicum virgatum L.), a significant perennial bioenergy crop. Our results demonstrated that introducing PvEIL3a into Arabidopsis slim1 mutants significantly increased the expression of genes responsive to sulphur deficiency, and transgenic plants exhibited shortened root length and delayed development. Moreover, PvEIL3a activated the expression of AtAPR1, AtSULTR1;1 and AtBGLU30, which plays an important role in sulphur assimilation and glucosinolate metabolism. Results of transcriptome and metabonomic analysis further indicated a perturbation in the metabolic pathways of tryptophan-dependent indole glucosinolates (IGs), camalexin and auxin. In addition, PvEIL3a conservatively regulated sulphur assimilation and the biosynthesis of tryptophan pathway-derived secondary metabolites, which reduced the biosynthesis of indole-3-acetic acid (IAA) and inhibited the root elongation of transgenic Arabidopsis. In conclusion, this study highlights the functional difference of the ethylene-insensitive 3-like (EIL) family gene in monocot and dicot plants, thereby deepening the understanding of the specific biological roles of EIL3 in monocot plant species.

Dual nematode infection in Brassica nigra affects shoot metabolome and aphid survival in distinct contrast to single-species infection.

Previous studies showed that aphid performance was compromised on Brassica nigra infected by root-lesion nematodes (Pratylenchus penetrans, Pp), but less, or positively influenced by root-knot nematode (Meloidogyne spp., Mi) infection. These experiments were on single-nematode infections, while naturally, roots are infected with several nematode species simultaneously. We performed greenhouse assays to assess the effects of single (Mi, Pp) and concurrent (MP)-nematode infections on aphid performance. Using targeted and untargeted profiling of leaf and phloem metabolomes, we examined how single- and concurrent-nematode infections affect shoot metabolomes, and elucidated the possible consequences on aphid performance. We found that the metabolic response towards double-infection is different from single-species infections. Moreover, Mi- and Pp-infections triggered discrete changes in B. nigra leaf and phloem metabolic profiles. Both Pp and MP-infections reduced aphid survival, suggesting that the biological effect could primarily be dominated by Pp-induced changes. This concurred with increased indole glucosinolates and hydroxycinnamic acid levels in the leaves, in particular the putative involvement of salicylic acid-2-O-β-D-glucoside. This study provides evidence that concurrent infection by different nematode species, as is common in natural environments, is associated with distinct changes in aboveground plant metabolomes, which are linked to differences in the survival of an aboveground herbivore.

Natural variation in BnaA07.MKK9 confers resistance to Sclerotinia stem rot in oilseed rape

Sclerotinia stem rot (SSR), caused by the necrotrophic fungus Sclerotinia sclerotiorum, is one of the most devastating diseases for several major oil-producing crops. Despite its impact, the genetic basis of SSR resistance in plants remains poorly understood. Here, through a genome-wide association study, we identify a key gene, BnaA07. MKK9, that encodes a mitogen-activated protein kinase kinase that confers SSR resistance in oilseed rape. Our functional analyses reveal that BnaA07.MKK9 interacts with BnaC03.MPK3 and BnaC03.MPK6 and phosphorylates them at the TEY activation motif, triggering a signaling cascade that initiates biosynthesis of ethylene, camalexin, and indole glucosinolates, and promotes accumulation of H2O2 and the hypersensitive response, ultimately conferring resistance. Furthermore, variations in the coding sequence of BnaA07.MKK9 alter its kinase activity and improve SSR resistance by ~30% in cultivars carrying the advantageous haplotype. These findings enhance our understanding of SSR resistance and may help engineer novel diversity for future breeding of oilseed rape.

Disease resistance of Brassica juncea to Sclerotinia sclerotiorum is established through the induction of indole glucosinolate biosynthesis

Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, is the main disease threat to oilseeds in Brassiceae, causing significant yield losses and reduction in oil content and quality. While the genetic mechanism underlying its lethal phenotype, particularly in B. juncea, remains largely unexplored. Transcriptome analysis revealed a large number of defense-related genes and response processes in B. napus and B. oleracea. However, similarities and differences in the defense responses to S. sclerotiorum on B. juncea are rarely reported. In the present study, we reported a B. juncea breeding line of H83 with high S. sclerotiorum resistance, which was used for transcriptome analysis compared to L36 with low resistance. A novel regulatory network was proposed to defend against S. sclerotiorum invasion in B. juncea. Upon infection of S. sclerotiorum, a series of were initiated within 12 h, and then defenses were activated to restrict the development and spread of S. sclerotiorum by inducing the massive synthesis of indole glucosinolates after 24 h. Twelve hub genes involved in the network were identified by the weighted gene co-expression network (WGCNA), which are involved in plant-pathogen interaction, signaling pathway genes, indole glucosinolate biosynthesis and cell wall formation. The hub genes were further validated by qRT-PCR. The research revealed a new resistant line of H83 against S. sclerotiorum and a different regulatory network in B. juncea, which would be beneficial for the future effective breeding of Sclerotinia-resistant varieties.

UV-B irradiation enhances the accumulation of beneficial glucosinolates induced by melatonin in Chinese kale sprout

Cruciferous sprout is a new form of vegetable product rich in bioactive compounds, especially glucosinolates. Previous studies have focused on increasing the accumulation of glucosinolates in cruciferous sprouts by applying different chemical regulators, with a particular focus on their contribution to nutritional quality and health benefits. Nevertheless, the effects of melatonin and UV-B irradiation on glucosinolate biosynthesis remain unclear. In this study, it was found that changes in melatonin concentrations significantly affected the contents of individual as well as total aliphatic and indolic glucosinolates. The 5 μmol · L−1 melatonin was decided as the optimum concentration that could increase the content of beneficial glucosinolates including glucoraphanin and 4-methoxy glucobrassicin in Chinese kale sprouts. Notably, the enhancement of glucosinolate accumulation by melatonin treatment could be further amplified by UV-B irradiation. Furthermore, our results showed that R2R3-MYB transcription factor BoaMYB28 and BoaMYB51, which are central regulators of aliphatic and indolic glucosinolate biosynthesis respectively, were both involved in the regulation of glucosinolate biosynthesis by melatonin and UV-B irradiation. Additionally, the expression of glucosinolate biosynthetic genes, including BoaCYP79F1, BoaCYP83A1, BoaSUR1, BoaUGT74B1, BoaCYP79B2, BoaCYP79B3, and BoaCYP83B1 participated in the formation of core structures and BoaFMOGS-OX5, BoaAOP2, BoaCYP81F2, and BoaIGMT1 involved in the side-chain modification of aliphatic and indolic glucosinolate, was regulated by melatonin or UV-B irradiation. Taken together, these findings provide a potential strategy for improving the nutritional quality and resistance of Chinese kale sprouts.

The RNA-Binding Protein BoRHON1 Positively Regulates the Accumulation of Aliphatic Glucosinolates in Cabbage.

Aliphatic glucosinolates are an abundant group of plant secondary metabolites in Brassica vegetables, with some of their degradation products demonstrating significant anti-cancer effects. The transcription factors MYB28 and MYB29 play key roles in the transcriptional regulation of aliphatic glucosinolates biosynthesis, but little is known about whether BoMYB28 and BoMYB29 are also modulated by upstream regulators or how, nor their gene regulatory networks. In this study, we first explored the hierarchical transcriptional regulatory networks of MYB28 and MYB29 in a model plant, then systemically screened the regulators of the three BoMYB28 homologs in cabbage using a yeast one-hybrid. Furthermore, we selected a novel RNA binding protein, BoRHON1, to functionally validate its roles in modulating aliphatic glucosinolates biosynthesis. Importantly, BoRHON1 induced the accumulation of all detectable aliphatic and indolic glucosinolates, and the net photosynthetic rates of BoRHON1 overexpression lines were significantly increased. Interestingly, the growth and biomass of these overexpression lines of BoRHON1 remained the same as those of the control plants. BoRHON1 was shown to be a novel, potent, positive regulator of glucosinolates biosynthesis, as well as a novel regulator of normal plant growth and development, while significantly increasing plants' defense costs.

Gregarines impact consumption and development but not glucosinolate metabolism in the mustard leaf beetle.

Gregarines are usually classified as parasites, but recent studies suggest that they should be viewed on a parasitism-mutualism spectrum and may even be seen as part of the gut microbiota of host insects. As such, they may also impact the consumption of their hosts and/or be involved in the digestion or detoxification of the host's diet. To study such effects of a gregarine species on those traits in its host, the mustard leaf beetle (Phaedon cochleariae) was used. This beetle species feeds on Brassicaceae plants that contain glucosinolates, which form toxic compounds when hydrolyzed by myrosinases. We cleaned host eggs from gametocysts and spores and reinfected half of the larvae with gregarines, to obtain gregarine-free (G-) and gregarine-infected (G+) larvae. Growth and food consumption parameters of these larvae were assessed by rearing individuals on watercress (Nasturtium officinale, Brassicaceae). A potential involvement of gregarines in the glucosinolate metabolism of P. cochleariae larvae was investigated by offering G- and G+ larvae leaf discs of watercress (containing mainly the benzenic 2-phenylethyl glucosinolate and myrosinases) or pea (Pisum sativum, Fabaceae, lacking glucosinolates and myrosinases) treated with the aliphatic 4-pentenyl glucosinolate or the indole 1-methoxy-3-indolylmethyl glucosinolate. Larval and fecal samples were analyzed via UHPLC-QTOF-MS/MS to search for breakdown metabolites. Larval development, body mass, growth rate and efficiency to convert food into body mass were negatively affected by gregarine infection while the pupal mass remained unaffected. The breakdown metabolites of benzenic and aliphatic glucosinolates were conjugated with aspartic acid, while those of the indole glucosinolate were conjugated with glutamic acid. Gregarine infection did not alter the larvae's ability to metabolize glucosinolates and was independent of plant myrosinases. In summary, some negative effects of gregarines on host performance could be shown, indicating parasitism. Future studies may further disentangle this gregarine-host relationship and investigate the microbiome potentially involved in the glucosinolate metabolism.

Effects of combined treatment of light quality and melatonin on health-promoting compounds in Chinese kale sprouts

Chinese kale sprouts have garnered attention owing to its rich health-promoting compounds. This study aimed to investigate the effects of different light qualities (white, blue, and red light) and melatonin (100 μmol L−1), both individually and in combination, on the growth and accumulation of health-promoting compounds in Chinese kale sprouts. Red light positively influenced sprout growth (compared with white light, plant height and fresh weight increased by 16.67 % and 4.87 %, respectively), and the red light + melatonin treatment further enhanced growth (compared with single red light, the plant height and fresh weight increased by 14.97 % and 12.29 %, respectively), while increasing glucosinolate accumulation through the up-regulation of glucosinolate biosynthetic genes (UGT74B1, CYP83B1, SOT18 and IGMT1). Conversely, blue light inhibited sprout growth, elevated the expression levels of PAL, CHS, CHI, GGP, and PAX, improved antioxidant levels, and accelerated the accumulation of aliphatic glucosinolates, reducing indolic glucosinolates. The blue light + melatonin treatment promoted the accumulation of sprout biomass and anthocyanins (11.91 % and 13.33 % higher than that of single blue light). The study unveiled various pathways influencing plant growth, development, and secondary metabolite accumulation, including plant circadian rhythms, ascorbate and aldarate metabolism, phenylpropanoid biosynthesis, and glucosinolate biosynthesis.

Heating conversion of indole-3-carbinol into N-substituted oligomers with anti-melanoma effect

Cruciferous vegetables (CVs) are globally consumed with some health benefits believed to arise from indole-3-carbinol (I3C), a labile phytochemical liberated from indole glucosinolates, but few reports describe the effect of cooking on I3C reactions. Here, we present heat-promoted direct conversions of I3C in broccoli florets into indole derivatives, which are unique in the N-indolylmethylation and -hydroxymethylation of indole nuclei by 3-methyleneindole and formaldehyde formed in situ from the I3C dehydration and the dimerization of I3C to 3,3′-diindolylmethane (DIM), respectively. Such N-substituted indoles were found in a range of 0.4–4.6 μg per gram of steamed broccoli florets, with a novel compound N-(indol-3-ylmethyl)-3,3′-diindolylmethane (DIM-1) bio-evaluated to inhibit A375 cells with an IC50 value of 1.87 μM. In aggregation, the investigation discloses the promoting effect of heating on the I3C transformation in CVs and identifies DIM-1 as an anti-cancer drug candidate, and thus updates the knowledge of I3C and bioactive derivatives thereof.

Growth conditions trigger genotype-specific metabolic responses that affect the nutritional quality of kale cultivars.

Kales (Brassica oleracea convar acephala) are fast-growing, nutritious leafy vegetables ideal for year-round indoor farming. However, selection of best cultivars for growth under artificial lighting necessitates a deeper understanding of leaf metabolism in different kale types. Here we examined a curly leaved cultivar Half Tall and a lacinato type cultivar Black Magic under moderate growth light (130 µmol photons m-1s-1/22°C) and high light (800 µmol photons m-1s-1/26°C) conditions. These conditions induced genotype-dependent differences in nutritionally important metabolites, especially anthocyanins and glucosinolates (GSLs), in the kale cultivars. In the pale green Half Tall, growth under high light conditions did not induce changes in either pigmentation or total GSL content. In contrast, the purple pigmentation of Black Magic intensified due to increased anthocyanin accumulation. Black Magic showed reduced amounts of indole GSLs and increased amounts of aliphatic GSLs under high light conditions, with notable cultivar-specific adjustments in individual GSL species. Correlation analysis of metabolite profiles suggested cultivar-specific metabolic interplay between serine biosynthesis and the production of indole GSLs. RNA sequencing identified candidate genes encoding metabolic enzymes and regulatory components behind anthocyanin and GSL biosynthesis. These findings improve the understanding of leaf metabolism and its effects on the nutritional quality of kale cultivars.

Modified atmosphere affects glucosinolate metabolism during postharvest storage of broccoli

Broccoli is a vegetable with a growing consumer demand worldwide due to its important nutritional properties, including high amounts of glucosinolates. However, this vegetable has a short postharvest life and quickly loses its organoleptic and nutritional quality. Modified atmosphere is one of the numerous methodologies used to delay deterioration during postharvest storage of broccoli heads. In this study, the effect of a modified atmosphere during postharvest storage of broccoli on glucosinolate metabolism was evaluated. Five glucosinolates were identified by using a UPLC system coupled to a mass spectrometer. We detected one aliphatic glucosinolate and four indolic glucosinolates, and their concentration was found to decrease during storage. The decrease in content was less marked, and in some cases, an increased level was observed in the treated samples. Moreover, the treatment made it possible to maintain higher expression (analyzed by real-time quantitative PCR) of genes linked to glucosinolate biosynthesis. We also detected an increased expression of some genes related to indolic glucosinolate biosynthesis. Overall, storage of broccoli in modified atmospheres allowed for maintaining better visual quality and higher levels of glucosinolates.

Individual and combined treatments of 2,4-epibrassinolide (EBR) and calcium chloride (CaCl2) maintain the postharvest quality of baby mustard

Baby mustard is a characteristic vegetable of the Southwest China, and its quality, including appearance quality and nutritional quality, deteriorated during the postharvest senescence process. This study investigated the effects of individual and combined treatments with 2,4-epibrassinolide (EBR) and calcium chloride (CaCl2) on the visual quality and health-promoting compounds of baby mustard stored at room temperature. In terms of appearance, individual treatments with EBR and CaCl2 were more effective than the control and combined treatment in sensory evaluation and weight loss inhibition. All three exogenous treatments maintained the content of pigments, especially individual treatments. The total chlorophyll content was 1.6-, 1.6-, and 1.1-fold higher in EBR-, CaCl2-, and EBR + CaCl2-treated samples than in control samples at 4 days, respectively. In terms of nutritional quality, all three exogenous treatments delayed the decrease in glucosinolates and soluble protein content, with EBR treatment being the most effective in preserving the content of indolic glucosinolates. Additionally, three exogenous treatments effectively maintained antioxidant levels, thereby reducing hydrogen peroxide accumulation. Combined treatment inhibited brassinosteroid signaling, revealing a potential antagonistic relationship between EBR and CaCl2. The results suggest that the three exogenous treatments delayed senescence and preserved the postharvest quality of baby mustard. EBR treatment was the most effective in preserving pigments. This experiment provides potential technical and theoretical basis for the postharvest preservation of baby mustard.

Interplay between secondary metabolites and plant hormones in silver nitrate-elicited Arabidopsis thaliana plants

Plants produce a myriad of specialized compounds in response to threats such as pathogens or pests and different abiotic factors. The stress-related induction of specialized metabolites can be mimicked using silver nitrate (AgNO3) as an elicitor, which application in conservation agriculture has gained interest. In Arabidopsis thaliana, AgNO3 triggers the accumulation of indole glucosinolates (IGs) and the phytoalexin camalexin as well as pheylpropanoid-derived defensive metabolites such as coumaroylagmatins and scopoletin through a yet unknown mechanism. In this work, the role of jasmonic (JA) and salicylic acid (SA) signaling in the AgNO3-triggered specialized metabolite production was investigated. To attain this objective, AgNO3, MeJA and SA were applied to A. thaliana lines impaired in JA or SA signaling, or affected in the endogenous levels of IGs and AGs. Metabolomics data indicated that AgNO3 elicitation required an intact JA and SA signaling to elicit the metabolic response, although mutants impaired in hormone signaling retained certain capacity to induce specialized metabolites. In turn, plants overproducing or abolishing IGs production had also an altered hormonal signaling response, both in the accumulation of signaling molecules and the molecular response mechanisms (ORA59, PDF1.2, VSP2 and PR1 gene expression), which pointed out to a crosstalk between defense hormones and specialized metabolites. The present work provides evidence of a crosstalk mechanism between JA and SA underlying AgNO3 defense metabolite elicitation in A. thaliana. In this mechanism, IGs would act as retrograde feedback signals dampening the hormonal response; hence, expanding the signaling molecule concept.

Characterization of Arabidopsis eskimo1 reveals a metabolic link between xylan O-acetylation and aliphatic glucosinolate metabolism.

Glucuronoxylan is present mainly in the dicot of the secondary cell walls, often O-acetylated, which stabilizes cell structure by maintaining interaction with cellulose and other cell wall components. Some members of the Golgi localized Trichome Birefringence-Like (TBL) family function as xylan O-acetyl transferase (XOAT). The primary XOAT in the stem of Arabidopsis is ESKIMO1/TBL29, and its disruption results in decreased xylan acetylation, stunted plant growth, and collapsed xylem vessels. To elucidate the effect on metabolic reprogramming and identify the underlying cause of the stunted growth in eskimo1, we performed transcriptomic, targeted, and untargeted metabolome analysis, mainly in the inflorescence stem tissue. RNA sequencing analysis revealed that the genes involved in the biosynthesis, regulation, and transport of aliphatic glucosinolates (GSLs) were upregulated, whereas those responsible for indolic GSL metabolism were unaffected in the eskimo1 inflorescence stem. Consistently, aliphatic GSLs, such as 4-methylsulfinylbutyl (4MSOB), were increased in stem tissues and seeds. This shift in the profile of aliphatic GSLs in eskimo1 was further supported by the quantification of the soluble acetate, decrease in accumulation of GSL precursor, i.e., methionine, and increase in the level of jasmonic acid.

Bioaccessible Organosulfur Compounds in Broccoli Stalks Modulate the Inflammatory Mediators Involved in Inflammatory Bowel Disease.

Inflammatory diseases are strongly associated with global morbidity and mortality. Several mediators are involved in this process, including proinflammatory interleukins and cytokines produced by damaged tissues that, somehow, act as initiators of the autoreactive immune response. Bioactive compounds present in plant-based foods and byproducts have been largely considered active agents with the potential to treat or prevent inflammatory diseases, being a valuable alternative to traditional therapeutic agents used nowadays, which present several side effects. In this regard, the present research uncovers the anti-inflammatory activity of the bioaccessible fraction of broccoli stalks processed, by applying different conditions that render specific concentrations of bioactive sulforaphane (SFN). The raw materials' extracts exhibited significantly different contents of total glucosinolates (GSLs) that ranged between 3993.29 and 12,296.48 mg/kg dry weight (dw), with glucoraphanin as the most abundant one, followed by GI and GE. The indolic GSLs were represented by hydroxy-glucobrassicin, glucobrassicin, methoxy-glucobrassicin, and neo-glucobrassicin, with the two latter as the most abundant. Additionally, SFN and indole-3-carbinol were found in lower concentrations than the corresponding GSL precursors in the raw materials. When exploring the bioaccessibility of these organosulfur compounds, the GSL of all matrices remained at levels lower than the limit of detection, while SFN was the only breakdown product that remained stable and at quantifiable concentrations. The highest concentration of bioaccessible SFN was provided by the high-ITC materials (~4.00 mg/kg dw). The results retrieved on the cytotoxicity of the referred extracts evidenced that the range of supplementation of growth media tested (0.002-430.400 µg of organosulfur compounds/mL) did not display cytotoxic effects on Caco-2 cells. The obtained extracts were assessed based on their capacity to reduce the production of key proinflammatory cytokines (interleukin 6 (IL-6), IL-8, and TNF-α) by the intestinal epithelium. Most of the tested processing conditions provided plant material with significant anti-inflammatory activity and the absence of cytotoxic effects. These data confirm that SFN from broccoli stalks, processed to optimize the bioaccessible concentration of SFN, may be potential therapeutic leads to treat or prevent human intestinal inflammation.

Dietary indole glucosinolates and skatole: Do they have a role in idiopathic pulmonary fibrosis: Case series data and review

Dietary indole glucosinolates and skatole: Do they have a role in idiopathic pulmonary fibrosis: Case series data and review

Effects of long-term blue light irradiation on carotenoid biosynthesis and antioxidant activities in Chinese cabbage (Brassica rapa L. ssp. pekinensis)

The aim of this study was to investigate the impact of long-term exposure to blue light-emitting diodes (LEDs) on the accumulation of indolic glucosinolates and carotenoids, as well as the plant growth and antioxidant activities in both orange and common Chinese cabbage (Brassica rapa L. ssp. pekinensis). Blue light treatment also induced higher ferric-reducing antioxidant power and 2,2-diphenyl-1-picrylhydrazyl by 20.66 % and 30.82 % and antioxidant enzyme activities catalase, peroxidase, superoxide dismutase, and the accumulation of non-enzymatic antioxidant substances (total phenols and total flavonoids) in the orange Chinese cabbage. Furthermore, long-term exposure to blue light had negative effects on the net photosynthetic rate and chlorophyll fluorescence levels. Meanwhile, blue light promoted accumulation of Indol-3-ylmethyl glucosinolate (I3M), β-carotene, lutein and zeaxanthin due to the high expression of regulatory and biosynthetic genes of the above metabolic pathways. In particular, lycopene and β-carotene content in orange Chinese cabbage increased by 60.14 % and 65.33 % compared to the ones in common line. The accumulation of carotenoid and increasing antioxidant levels in the orange cabbage line was influenced by long-term blue light irradiation, leading to better tolerance to low temperature and drought stresses. The up-regulation of transcription factors such as BrHY5-2, BrPIF4 and BrMYB12 may also contribute to the increased tolerance in orange Chinese cabbage to extreme environmental stresses. The BrHY5-2 gene could activate carotenoid biosynthetic genes and induce the accumulation of carotenoids. These findings suggested that long-term blue light irradiation could be a promising technique for increasing the nutrition value and enhancing tolerance to low temperature and drought stresses in Chinese cabbage.