Natural isothiocyanates: genotoxic potential versus chemoprevention

Nutritional Sources and Anticancer Potential of Phenethyl Isothiocyanate: Molecular Mechanisms and Therapeutic Insights

Phenethyl isothiocyanate (PEITC), a compound derived from cruciferous vegetables, has garnered attention for its anticancer properties. This review synthesizes existing research on PEITC, focusing on its mechanisms of action in combatting cancer. PEITC has been found to be effective against various cancer types, such as breast, prostate, lung, colon, and pancreatic cancers. Its anticancer activities are mediated through several mechanisms, including the induction of apoptosis (programmed cell death), inhibition of cell proliferation, suppression of angiogenesis (formation of new blood vessels that feed tumors), and reduction of metastasis (spread of cancer cells to new areas). PEITC targets crucial cellular signaling pathways involved in cancer progression, notably the Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB), Protein Kinase B (Akt), and Mitogen-Activated Protein Kinase (MAPK) pathways. These findings suggest PEITC's potential as a therapeutic agent against cancer. However, further research is necessary to determine the optimal dosage, understand its bioavailability, and assess potential side effects. This will be crucial for developing PEITC-based treatments that are both effective and safe for clinical use in cancer therapy.

Anticarcinogenic Effects of Isothiocyanates on Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, accounting for about 90% of cases. Sorafenib, lenvatinib, and the combination of atezolizumab and bevacizumab are considered first-line treatments for advanced HCC. However, clinical application of these drugs has also caused some adverse reactions such as hypertension, elevated aspartate aminotransferases, and proteinuria. At present, natural products and their derivatives have drawn more and more attention due to less side effects as cancer treatments. Isothiocyanates (ITCs) are one type of hydrolysis products from glucosinolates (GLSs), secondary plant metabolites found exclusively in cruciferous vegetables. Accumulating evidence from encouraging in vitro and in vivo animal models has demonstrated that ITCs have multiple biological activities, especially their potentially health-promoting activities (antibacterial, antioxidant, and anticarcinogenic effects). In this review, we aim to comprehensively summarize the chemopreventive, anticancer, and chemosensitizative effects of ITCs on HCC, and explain the underlying molecular mechanisms.

Novel archetype in cancer therapeutics: exploring prospective of phytonanocarriers

This paper reports various types of cancer, their incidence, and prevalence all over the globe. Along with the discovery of novel natural drugs for cancer treatment, these present a promising option which are eco-friendly, safe, and provide better acceptability in comparison to synthetic agents that carries multiple side effects. This paper provides an idea about various nanocarriers and phytochemicals, along with how their solubility and bioavailability can be enhanced in nanocarrier system. This report combines the data from various literature available on public domain including PubMed on research articles, reviews, and along with report from various national and international sites. Specialized metabolites (polyphenols, alkaloids, and steroids etc) from medicinal plants are promising alternatives to existing drugs. Studies have suggested that the treatment of cancer using plant products could be an alternative and a safe option. Studies have shown with the several cell lines as well as animal models, that phytomolecules are important in preventing/treating cancer. Phytochemicals often outperform chemical treatments by modulating a diverse array of cellular signaling pathways, promoting cell cycle arrest, apoptosis activation, and metastatic suppression, among others. However, limited water solubility, bioavailability, and cell penetration limit their potential clinical manifestations. The development of plant extract loaded nanostructures, rendering improved specificity and efficacy at lower concentrations could prove effective. Nanocarriers, such as liposomes, nanostructured lipids, polymers, and metal nanoparticles, have been tested for the delivery of plant products with enhanced effects. Recent advances have achieved improvement in the the stability, solubility, bioavailability, circulation time, and target specificity by nanostructure-mediated delivery of phytochemicals. Nanoparticles have been considered and attempted as a novel, targeted, and safe option. Newer approaches such as phyto-nanocarriers with carbohydrates, lignin, and polymers have been considered even more selective and effective modes of drug delivery in biomedical or diagnostic applications.

Effects of Sulforaphane-Induced Cell Death upon Repeated Passage of Either P-Glycoprotein-Negative or P-Glycoprotein-Positive L1210 Cell Variants

The expression of the membrane ABCB1 transporter in neoplastic cells is one of the most common causes of reduced sensitivity to chemotherapy. In our previous study, we investigated the effect of a single culture of ABCB1-negative (S) and ABCB1-positive variants of L1210 cells (R and T) in the presence of sulforaphane (SFN). We demonstrated that SFN induces the onset of autophagy more markedly in S cells than in R or T cells. In the current study, we focused on the effect of the repeated culture of S, R and T cells in SFN-containing media. The repeated cultures increased the onset of autophagy compared to the simple culture, mainly in S cells and to a lesser extent in R and T cells, as indicated by changes in the cellular content of 16 and 18 kDa fragments of LC3B protein or changes in the specific staining of cells with monodansylcadaverine. We conclude that SFN affects ABCB1-negative S cells more than ABCB1-positive R and T cells during repeated culturing. Changes in cell sensitivity to SFN appear to be related to the expression of genes for cell-cycle checkpoints, such as cyclins and cyclin-dependent kinases.

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.

Glucosinolates, Ca, Se Contents, and Bioaccessibility in Brassica rapa Vegetables Obtained by Organic and Conventional Cropping Systems

In northwest Spain and Portugal, there is a long tradition of cultivating B. rapa subsp. rapa to obtain turnip greens and turnip tops. Brassica rapa L. subsp. rapa (turnip greens and turnip tops) were grown under conventional and organic conditions in two Farms in southern Spain. Glucosinolatescontents were higher in Brassicas grown under conventional conditions than those grown under organic ones. Average Ca total and bioaccessible contents ranged between 14.6–23.4 mg/g; 8.9–12.0 mg/g for turnip greens and 6.4–8.9 mg/g; 4.3–4.8 mg/g for turnip tops. According to these concentrations, an intake of 100–200 g (fresh weight) of the studied Brassica rapa fulfills Ca dietary reference intakes (DRI) (considering the total content data) and complies with 72–100% Ca DRI percentage (considering the bioaccessible data). Se concentrations ranged between 0.061–0.073 µg/g and 0.039–0.053 µg/g for turnip greens and turnip tops respectively. Se bioaccessibility values were high, with percentages of around 90%. Finally, the total glucosinolate content ranged between 13.23–21.28 µmol/g for turnip greens and 13.36–20.20 µmol/g for turnip tops. In general, the bioaccessibility of the total glucosinolates analyzed in this study was high, with mean values of around 73% and 66% for turnip greens and turnip tops, respectively. Brassica rapa vegetables grown under both organic and conventional conditions in southern Spain are an excellent dietary source of Ca, Se, and glucosinolates with a high bioaccessibility.

Beneficial Health Effects of Glucosinolates-Derived Isothiocyanates on Cardiovascular and Neurodegenerative Diseases

Neurodegenerative diseases (NDDs) and cardiovascular diseases (CVDs) are illnesses that affect the nervous system and heart, all of which are vital to the human body. To maintain health of the human body, vegetable diets serve as a preventive approach and particularly Brassica vegetables have been associated with lower risks of chronic diseases, especially NDDs and CVDs. Interestingly, glucosinolates (GLs) and isothiocyanates (ITCs) are phytochemicals that are mostly found in the Cruciferae family and they have been largely documented as antioxidants contributing to both cardio- and neuroprotective effects. The hydrolytic breakdown of GLs into ITCs such as sulforaphane (SFN), phenylethyl ITC (PEITC), moringin (MG), erucin (ER), and allyl ITC (AITC) has been recognized to exert significant effects with regards to cardio- and neuroprotection. From past in vivo and/or in vitro studies, those phytochemicals have displayed the ability to mitigate the adverse effects of reactive oxidation species (ROS), inflammation, and apoptosis, which are the primary causes of CVDs and NDDs. This review focuses on the protective effects of those GL-derived ITCs, featuring their beneficial effects and the mechanisms behind those effects in CVDs and NDDs.

Anti-Cancer and Medicinal Potentials of Moringa Isothiocyanate

Moringa oleifera (M. oleifera), which belongs to the Moringaceae family, is a common herb, rich in plant compounds. It has a variety of bioactive compounds that can act as antioxidants, antibiotics, anti-inflammatory and anti-cancer agents, etc., which can be obtained in different body parts of M. oleifera. Isothiocyanates (ITCs) from M. oleifera are one class of these active substances that can inhibit cancer proliferation and promote cancer cell apoptosis through multiple signaling pathways, thus curbing cancer migration and metastasis, at the same time they have little adverse effect on normal cells. There are multiple variants of ITCs in M. oleifera, but the predominant phytochemical is 4-(α-L-rhamnosyloxy)benzyl isothiocyanate, also known as moringa isothiocyanate (MIC-1). Studies have shown that MIC-1 has the possibility to be used clinically for the treatment of diabetes, neurologic diseases, obesity, ulcerative colitis, and several cancer types. In this review, we focus on the molecular mechanisms underlying the anti-cancer and anti-chronic disease effects of MIC-1, current trends, and future direction of MIC-1 based treatment strategies. This review combines the relevant literature of the past 10 years, in order to provide more comprehensive information of MIC-1 and to fully exploit its potentiality in the clinical settings.

Chemoinformatic Analysis of Isothiocyanates: Their Impact in Nature and Medicine

Isothiocyanates (ITCs) have a significant impact on food and natural product chemistry. Several dietary components and food chemicals contain the isothiocyanate moiety. In addition, many ITCs interact with macromolecules of biological relevance, making these compounds relevant for potential therapeutic applications and disease prevention. However, there is a lack of systematic analysis of ITCs in chemical and biological databases. Herein, we conducted a comprehensive analysis of ITCs present in public domain databases, including natural products, food chemicals, macromolecular targets of drugs, and the Protein Data Bank. A total of 154 ITCs were found, which can be classified into seven categories: acyclic, cyclic, polycyclic, aromatic, polyaromatic, indolic, and glycosylated. 24 ITCs were reported in 18 vegetable sources, mainly in cruciferous vegetables (Brassica oleracea L.). Calculated properties of pharmaceutical relevance indicated that 11 % of the 154 ITCs would be suitable to be orally absorbed and 48 % permeate the blood-brain-barrier. It was also found that seven molecular targets have been co-crystallized with ITCs and the most frequent is the macrophage migration inhibitory factor. It is expected that this work will contribute to the sub-disciplines of natural products and food informatics.

Sulforaphane as a potential remedy against cancer: Comprehensive mechanistic review

Sulforaphane belongs to the active class of isothiocyanates capable of delivering various biological benefits for health promotion and disease prevention. This compound is considered vital to curtail numerous metabolic disorders. Various studies have proven its beneficial effects against cancer prevention and its possible utilization as a therapeutic agent in cancer treatment. Understanding the mechanistic pathways and possible interactions at cellular and subcellular levels is key to design and develop cancer therapeutics for humans. In this respect, a number of mechanisms such as modulation of carcinogen metabolism & phase II enzymatic activities, cell cycle arrest, activation of Nrf2, cytotoxic, proapoptotic and apoptotic pathways have been reported to be involved in cancer prevention. This article provides sufficient information by critical analysis to understand the mechanisms involved in cancer prevention attributed to sulforaphane. Furthermore, various clinical studies have also been included for design and development of novel therapies for cancer prevention and cure. PRACTICAL APPLICATIONS: Diet and dietary components are potential tools to address various lifestyle-related disorders. Due to plenty of environmental and cellular toxicants, the chances of cancer prevalence are quite large which are worsen by adopting unhealthy lifestyles. Cancer can be treated with various therapies but those are acquiring side effects causing the patients to suffer the treatment regime. Nutraceuticals and functional foods provide safer options to prevent or delay the onset of cancer. In this regard, sulforaphane is a pivotal compound to be targeted as a potential agent for cancer treatment both in preventive and therapeutic regimes. This article provides sufficient evidence via discussing the underlying mechanisms of positive effects of sulforaphane to further the research for developing anticancer drugs that will help assuage this lethal morbidity.

JNK signaling as a target for anticancer therapy

The JNKs are members of mitogen-activated protein kinases (MAPK) which regulate many physiological processes including inflammatory responses, macrophages, cell proliferation, differentiation, survival, and death. It is increasingly clear that the continuous activation of JNKs has a role in cancer development and progression. Therefore, JNKs represent attractive oncogenic targets for cancer therapy using small molecule kinase inhibitors. Studies showed that the two major JNK proteins JNK1 and JNK2 have opposite functions in different types of cancers, which need more specification in the design of JNK inhibitors. Some of ATP- competitive and ATP non-competitive inhibitors have been developed and widely used in vitro, but this type of inhibitors lack selectivity and inhibits phosphorylation of all JNK substrates and may lead to cellular toxicity. In this review, we summarized and discussed the strategies of JNK binding inhibitors and the role of JNK signaling in the pathogenesis of different solid and hematological malignancies.

Dietary isothiocyanates inhibit cancer progression by modulation of epigenome

Cell cycle, growth, survival and metabolism are tightly regulated together and failure in cellular regulation leads to carcinogenesis. Several signaling pathways like the PI3K, WNT, MAPK and NFKb pathway exhibit aberrations in cancer and help achieve hallmark capabilities. Clinical research and in vitro studies have highlighted the role of epigenetic alterations in cancer onset and development. Altered gene expression patterns enabled by changes in DNA methylation, histone modifications and RNA processing have proven roles in cancer hallmark acquisition. The reversible nature of epigenetic processes offers robust therapeutic targets. Dietary bioactive compounds offer a vast compendium of effective therapeutic moieties. Isothiocyanates (ITCs) sourced from cruciferous vegetables demonstrate anti-proliferative, pro-apoptotic, anti-inflammatory, anti-migratory and anti-angiogenic effect against several cancers. ITCs also modulate the redox environment, modulate signaling pathways including PI3K, MAPK, WNT, and NFkB. They also modulate the epigenetic machinery by regulating the expression and activity of DNA methyltransferases, histone modifiers and miRNA. This further enhances their transcriptional modulation of key cellular regulators. In this review, we comprehensively assess the impact of ITCs such as sulforaphane, phenethyl isothiocyanate, benzyl isothiocyanate and allyl isothiocyanate on cancer and document their effect on various molecular targets. Overall, this will facilitate consolidation of the current understanding of the anti-cancer and epigenetic modulatory potential of these compounds and recognize the gaps in literature. Further, we discuss avenues of future research to develop these compounds as potential therapeutic entities.

Cell Death Effects Induced by Sulforaphane and Allyl Isothiocyanate on P-Glycoprotein Positive and Negative Variants in L1210 Cells

Variants of L1210 leukemia cells-namely, parental P-glycoprotein-negative S cells and R and T cells expressing P-glycoprotein, due to selection with vincristine and transfection with the human p-glycoprotein gene, respectively-were used. The responses of these cell variants to two naturally occurring isothiocyanates-sulforaphane (SFN, from cruciferous vegetables) and allyl isothiocyanate (AITC, from mustard, radish, horseradish and wasabi)-were studied. We obtained conflicting results for the cell death effects induced by isothiocyanates, as measured by i. cell counting, which showed inhibited proliferation, and ii. cell metabolic activity via an MTS assay, which showed an increased MTS signal. These results indicated the hyperactivation of cell metabolism induced by treatment with isothiocyanates. In more detailed study, we found that, depending on the cell variants and the isothiocyanate used in treatment, apoptosis and necrosis (detected by annexin-V cells and propidium iodide staining), as well as autophagy (detected with monodansylcadaverine), were involved in cell death. We also determined the cell levels/expression of Bcl-2 and Bax as representative anti- and pro-apoptotic proteins of the Bcl-2 family, the cell levels/expression of members of the canonical and noncanonical NF-κB pathways, and the cell levels of 16 and 18 kDa fragments of LC3B protein as markers of autophagy.

Local/traditional uses, secondary metabolites and biological activities of Mashua (Tropaeolum tuberosum Ruíz & Pavón)

ETHNOPHARMACOLOGICAL RELEVANCE

Tropaeolum tuberosum Ruíz & Pavón (Tropaeolaceae). Sim (commonly called Mashua) is an indigenous plant that has medicinal values for various ethnic groups of the regions of the Andes mountain range of South America, which use it for the treatment of diseases venereal, lung and skin; for the healing of internal and external wounds; and as an analgesic for kidney and bladder pain.

AIM OF THE REVIEW

We critically summarised the current evidence on the botanic characterisation and distribution, ethnopharmacology, secondary metabolites, pharmacological activities, qualitative and quantitative analysis, and toxicology of T. tuberosum.

MATERIALS AND METHODS

The relevant information on T. tuberosum was gathered from worldwide accepted scientific databases via electronic search (Google scholar, Elsevier, SciFinder, ScienceDirect, PubMed, SpringerLink, Web of Science, Scopus, Wiley Online, Mendeley, Scielo and Dialnet electronic databases). Information was also obtained from the literature and books as well as PhD and MSc dissertations. Plant names were validated by 'The Plant List' (www.theplantlist.org).

RESULTS

T. tuberosum has diverse uses in local and popular medicine, specifically for relieving pain and infections in humans. Regarding its biological activities, polar extracts (aqueous, hydroalcoholic) and isolated compounds from the tubers have exhibited a wide range of in vitro and in vivo pharmacological effects, including antibacterial, antioxidant, anti-inflammatory activities. Quantitative analysis (e.g., NMR, HPLC, GC-MS) indicated the presence of a set of secondary metabolites, including hydroxybenzoic acids, tannins, flavanols, anthocyanins, glucosinolates, isothiocyanates, phytosterols, fatty acids and alkamides in the tubers of T. tuberosum. Likewise, glucosinolates have been identified in the seeds and isothiocyanates have been detected in leaves, flowers and seeds.

CONCLUSIONS

T. tuberosum has been tested for various biological activities and the extracts (tubers in particular) demonstrated a promising potential as an antibacterial, antioxidant, anti-inflammatory and inhibitors of benign prostatic hyperplasia. A lack of alignment between the ethno-medicinal uses and existing biological screenings was observed, indicating the need to explore its potential for the treatment against respiratory affections, urinary affections and blood diseases. Likewise, it is necessary to analyse deeply the relationship that exists between the different tuber colours of T. tuberosum and its use for the treatment of certain diseases. Validation of clinical studies of the antibacterial, antioxidant/anti-inflammatory, anti-spermatogenic activities and as inhibitors of benign prostatic hyperplasia is required. Moreover, studies on the toxicity, bioavailability, and pharmacokinetics, in addition to clinical trials, are indispensable for assessing the safety and efficacy of the active metabolites or extracts obtained from T. tuberosum. Other areas that need investigation are the development of future applications based on their active metabolites, such as neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, Huntington's disease). Finally, the work purposes to motivate other research groups to carry out a series of scientific studies that can fill the gaps that exist with respect to Mashua properties, and thus be able to change the focus of T. tuberosum (Mashua) that currently has in the consumer society.

Repurposing old drugs as new inhibitors of the ubiquitin-proteasome pathway for cancer treatment

The ubiquitin-proteasome system (UPS) plays a central role in the degradation of cellular proteins. Targeting protein degradation has been validated as an effective strategy for cancer therapy since 2003. Several components of the UPS have been validated as potential anticancer targets, including 20S proteasomes, 19S proteasome-associated deubiquitinases (DUBs) and ubiquitin ligases (E3s). 20S proteasome inhibitors (such as bortezomib/BTZ and carfilzomib/CFZ) have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of multiple myeloma (MM) and some other liquid tumors. Although survival of MM patients has been improved by the introduction of BTZ-based therapies, these clinical 20S proteasome inhibitors have several limitations, including emergence of resistance in MM patients, neuro-toxicities, and little efficacy in solid tumors. One of strategies to improve the current status of cancer treatment is to repurpose old drugs with UPS-inhibitory properties as new anticancer agents. Old drug reposition represents an attractive drug discovery approach compared to the traditional de novo drug discovery process which is time-consuming and costly. In this review, we summarize status of repurposed inhibitors of various UPS components, including 20S proteasomes, 19S-associated DUBs, and ubiquitin ligase E3s. The original and new mechanisms of action, molecular targets, and potential anticancer activities of these repurposed UPS inhibitors are reviewed, and their new uses including combinational therapies for cancer treatment are discussed.

Benzyl Isothiocyanate Induces Apoptosis via Reactive Oxygen Species-Initiated Mitochondrial Dysfunction and DR4 and DR5 Death Receptor Activation in Gastric Adenocarcinoma Cells

Benzyl isothiocyanate (BITC) is known to inhibit the metastasis of gastric cancer cells but further studies are needed to confirm its chemotherapeutic potential against gastric cancer. In this study, we observed cell shrinkage and morphological changes in one of the gastric adenocarcinoma cell lines, the AGS cells, after BITC treatment. We performed 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2H-tetrazolium bromide (MTT) assay, a cell viability assay, and found that BITC decreased AGS cell viability. Reactive oxygen species (ROS) analyses using 2',7'-dichlorofluorescin diacetate (DCFDA) revealed that BITC-induced cell death involved intracellular ROS production, which resulted in mitochondrial dysfunction. Additionally, cell viability was partially restored when BITC-treated AGS cells were preincubated with glutathione (GSH). Western blotting indicated that BITC regulated the expressions of the mitochondria-mediated apoptosis signaling molecules, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), and cytochrome c (Cyt c). In addition, BITC increased death receptor DR5 expression, and activated the cysteine-aspartic proteases (caspases) cascade. Overall, our results showed that BITC triggers apoptosis in AGS cells via the apoptotic pathways involved in ROS-promoted mitochondrial dysfunction and death receptor activation.

Modulation of hepatic ABC transporters by Eruca vesicaria intake: Potential diet-drug interactions

The aim of this work was to evaluate whether oral administration of Eruca vesicaria, a species of rocket cultivated in Argentina, could modify cyclophosphamide (CP)-induced genotoxicity through modulation of hepatic ABC transporters. Daily oral administration of E. vesicaria fresh leaves juice (1.0, 1.4 and 2.0  g/kg) for 14 days did not alter genotoxicity biomarkers -alkaline comet assay and micronucleus test -in neither male nor female mice. Instead, repeated intake of this cruciferous decreased CP-induced DNA damage dose-dependently and it caused hepatic overexpression of P-glycoprotein (P-gp; 1.4 and 2.0  g/kg) and multidrug resistance protein 2 (MRP2; 2.0  g/kg), but not breast cancer resistance protein (Bcrp). The antigenotoxic effect of E. vesicaria was prevented by 50 mg/kg verapamil (P-gp inhibitor) or 10 mg/kg indomethacin (MRP2 inhibitor). In turn, CP-induced cytotoxicity (10 mM, 24 h) on human hepatoma cells (HepG2/C3A) was significantly reduced by preincubation with E. vesicaria (1.4 mg/ml; 48 h); this effect was absent when CP was coincubated with 35 μM verapamil, 80 μM indomethacin or 10 μM KO-143 (BCRP inhibitor). Altogether, these results allow us to demonstrate that repeated intake of E. vesicaria exhibited antigenotoxicity, at least in part, by induction of hepatic ABC transporters in vivo in mice as well as in vitro in human liver cells. This could account for other diet-drug interactions.

Glucosinolates: Molecular structure, breakdown, genetic, bioavailability, properties and healthy and adverse effects

Glucosinolates are a large group of plant secondary metabolites with nutritional effects and biologically active compounds. Glucosinolates are mainly found in cruciferous plants such as Brassicaceae family, including common edible plants such as broccoli (Brassica oleracea var. italica), cabbage (B. oleracea var. capitata f. alba), cauliflower (B. oleracea var. botrytis), rapeseed (Brassica napus), mustard (Brassica nigra), and horseradish (Armoracia rusticana). If cruciferous plants are consumed without processing, myrosinase enzyme will hydrolyze the glucosinolates to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. On the other hand, when cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. This review paper summarizes the glucosinolate molecular breakdown, their genetic aspects from biosynthesis to precursors, their bioavailability (assimilation, absorption, and elimination of these molecules), their sensory properties, identified healthy and adverse effects, as well as the impact of processing on their bioavailability.

Diverse Excretion Pathways of Benzyl Glucosinolate in Humans after Consumption of Nasturtium (Tropaeolum majus L.)-A Pilot Study

SCOPE

Different metabolic and excretion pathways of the benzyl glucosinolate breakdown products benzyl isothiocyanate and benzyl cyanide are investigated to obtain information about their multiple fate after ingestion. Detailed focus is on the so far underestimated transformation/excretion pathways-protein conjugation and exhalation.

METHODS AND RESULTS

Metabolites, protein conjugates, and non-conjugated isothiocyanates are determined in plasma, urine, and breath of seven volunteers after consuming freeze-dried nasturtium or bread enriched with nasturtium. Samples are collected up to 48 h at selected time points. The metabolites of the mercapturic acid pathway are detectable in plasma up to 24 h after consumption. Additionally, mercapturic acid is the main metabolite in urine, but non-conjugated benzyl isothiocyanate is detectable as well. Protein conjugates show high amounts in plasma even 48 h after consumption. In breath, benzyl isothiocyanate and benzyl cyanide are detectable up to 48 h after consumption.

CONCLUSION

Isothiocyanates are not only metabolized via the mercapturic acid pathway, but also form protein conjugates in blood and are exhaled. To balance intake and excretion, it is necessary to investigate all potential metabolites and excretion routes. This has important implications for the understanding of physiological and pharmacological effects of isothiocyanate-containing products.

In Vitro Determination of Protein Conjugates in Human Cells by LC-ESI-MS/MS after Benzyl Isothiocyanate Exposure

Glucosinolates and their breakdown products, especially isothiocyanates (ITCs), are hypothesized to exert a broad range of bioactivities. However, physiological mechanisms are not yet completely understood. In this study, formation of protein conjugates after incubation with benzyl isothiocyanate (BITC) was investigated in vitro. A survey of protein conjugates was done by determining BITC cysteine and lysine amino acid conjugates after protein digestion. Therefore, a liquid chromatography-tandem mass spectrometry (LC-ESI-MS/MS) method was developed and validated. Stability studies showed that cysteine conjugates are not stable under alkaline conditions, and lysine conjugates did not show any correlation to pH values, although stability increased at low temperatures. Lysine conjugates were the preferred form of protein conjugates, and longer BITC exposure times led to higher amounts. Knowledge about the reaction sites of ITCs in eukaryotic cells may help to understand the mode of action of ITCs leading to health promoting as well as toxicological effects in humans.

Food as Pharma? The Case of Glucosinolates

BACKGROUND

Glucosinolates (GLSs) are dietary plant secondary metabolites occurring in the order Brassicales with potential health effects, in particular as anti-carcinogenic compounds. GLSs are converted into a variety of breakdown products (BPs) upon plant tissue damage and by the gut microbiota. GLS biological activity is related to BPs rather than to GLSs themselves.

METHODS

we have reviewed the most recent scientific literature on the metabolic fate and the biological effect of GLSs with particular emphasis on the epidemiological evidence for health effect and evidence from clinical trials. An overview of potential molecular mechanisms underlying GLS biological effect is provided. The potential toxic or anti-nutritional effect has also been discussed.

RESULTS

Epidemiological and human in vivo evidence point towards a potential anti-cancer effect for sulforaphane, indole-3-carbinol and 3,3-diindolylmethane. A number of new human clinical trials are on-going and will likely shed further light on GLS protective effect towards cancer as well as other diseases. BPs biological effect is the results of a plurality of molecular mechanisms acting simultaneously which include modulation of xenobiotic metabolism, modulation of inflammation, regulation of apoptosis, cell cycle arrest, angiogenesis and metastasis and regulation of epigenetic events. BPs have been extensively investigated for their protective effect towards cancer but in recent years the interest also includes other diseases.

CONCLUSION

It appears that certain BPs may protect against and may even represent a therapeutic strategy against several forms of cancer. Whether this latter effect can be achieved through diet or supplements should be investigated more thoroughly.

Structures of isothiocyanates attributed to reactive oxygen species generation and microtubule depolymerization in HepG2 cells

The structure of the isothiocyanates (ITCs)-erucin, sulforaphane, erysolin, sulforaphene, and phenethyl isothiocyanate-were assessed as well as their respective in vitro anticancer activity on the hepatocellular carcinoma cell line HepG2. All of these ITCs induced both apoptotic and necrotic cell death. FTIR analysis indicated that the ITCs caused changes in cellular components comparable to vinblastine. Despite no observable effect on DNA, the ITCs all induced generation of intracellular reactive oxygen species (ROS) and suppressed microtubule polymerization. The variation in sulfur oxidation states and the presence of an aromatic ring on the ITC side chain affected microtubule depolymerization and intracellular ROS generation, leading to apoptotic and necrotic cancer cell death. Knowing the influences of structural variations of the ITC side chain would be useful for selecting the more potent ITCs (i.e., erysolin) for the design and development of effective chemopreventive agents.

Chemoprevention with isothiocyanates - From bench to bedside

Isothiocyanates (ITCs) are naturally occurring hydrolization products from glucosinolates (GLSs) in brassicaceae and in epidemiological studies their intake has been weakly to moderately inversely correlated with the risk of colorectal cancer, prostate cancer and lung cancer. Numerous preclinical studies demonstrate chemopreventive mode of actions of ITCs, mainly related to a.) detoxification (induction of phase II enzymes), b.) anti-inflammatory properties by down-regulation of NFkappaB activity, c.) cyclin-mediated cell cycle arrest and d.) epigenetic modulation by inhibition of histone deacetylase activity. First prospective clinical trials were promising in patients with risk of prostate cancer recurrence. The glutathione-S-transferase gene expression seems to play a major role in the individual susceptibility towards ITCs. Safety issues are widely unclear and should be more addressed in future studies because ITCs can, in low concentrations, compromise the function of human immune cells and might impair genome stability.

Stability of Bioactive Compounds in Broccoli as Affected by Cutting Styles and Storage Time

Broccoli contains bioactive molecules and thus its consumption is related with the prevention of chronic and degenerative diseases. The application of wounding stress to horticultural crops is a common practice, since it is the basis for the fresh-cut produce industry. In this study, the effect of four different cutting styles (CSs) (florets (CS1), florets cut into two even pieces (CS2), florets cut into four even pieces (CS3), and florets processed into chops (CS4)) and storage time (0 and 24 h at 20 °C) on the content of bioactive compounds in broccoli was evaluated. Immediately after cutting, 5-O-caffeoylquinic acid and caffeic acid content increased by 122.4% and 41.6% in CS4 and CS2, respectively. Likewise, after storage, 3-O-caffeoylquinic acid and 5-O-caffeoylquinic acid increased by 46.7% and 98.2%, respectively in CS1. Glucoerucin and gluconasturtiin content decreased by 62% and 50%, respectively in CS3; whereas after storage most glucosinolates increased in CS1. Total isothiocyanates, increased by 133% immediately in CS4, and after storage CS1 showed 65% higher levels of sulforaphane. Total ascorbic acid increased 35% after cutting in CS2, and remained stable after storage. Results presented herein would allow broccoli producers to select proper cutting styles that preserve or increase the content of bioactive molecules.

Identification of cancer chemopreventive isothiocyanates as direct inhibitors of the arylamine N-acetyltransferase-dependent acetylation and bioactivation of aromatic amine carcinogens

Aromatic amines (AAs) are chemicals of industrial, pharmacological and environmental relevance. Certain AAs, such as 4-aminobiphenyl (4-ABP), are human carcinogens that require enzymatic metabolic activation to reactive chemicals to form genotoxic DNA adducts. Arylamine N-acetyltransferases (NAT) are xenobiotic metabolizing enzymes (XME) that play a major role in this carcinogenic bioactivation process. Isothiocyanates (ITCs), including benzyl-ITC (BITC) and phenethyl-ITC (PEITC), are phytochemicals known to have chemopreventive activity against several aromatic carcinogens. In particular, ITCs have been shown to modify the bioactivation and subsequent mutagenicity of carcinogenic AA chemicals such as 4-ABP. However, the molecular and biochemical mechanisms by which these phytochemicals may modulate AA carcinogens bioactivation and AA-DNA damage remains poorly understood.

This manuscript provides evidence indicating that ITCs can decrease the metabolic activation of carcinogenic AAs via the irreversible inhibition of NAT enzymes and subsequent alteration of the acetylation of AAs. We demonstrate that BITC and PEITC react with NAT1 and inhibit readily its acetyltransferase activity (k_i = 200 M⁻¹.s⁻¹ and 66 M⁻¹.s⁻¹ for BITC and PEITC, respectively). Chemical labeling, docking approaches and substrate protection assays indicated that inhibition of the acetylation of AAs by NAT1 was due to the chemical modification of the enzyme active site cysteine. Moreover, analyses of AAs acetylation and DNA adducts in cells showed that BITC was able to modulate the endogenous acetylation and bioactivation of 4-ABP. In conclusion, we show that direct inhibition of NAT enzymes may be an important mechanism by which ITCs exert their chemopreventive activity towards AA chemicals.

Nutrigenomic effects of glucosinolates on liver, muscle and distal kidney in parasite-free and salmon louse infected Atlantic salmon

Background

Reduction of Lepeophtheirus salmonis infection in Atlantic salmon achieved by glucosinolates (GLs) from Brassica plants was recently reported. However, wider application of functional feeds based on GLs requires better knowledge of their positive and adverse effects.

Methods

Liver, distal kidney and muscle transcriptomes of salmon exposed to the extreme dose of GLs were profiled by microarray, while qPCR analysis followed up selected hepatic and renal responses under the extreme and moderate GLs dose during the L. salmonis challenge. Transcriptional analysis were complemented with measurements of organ indices, liver steatosis and plasma profiling, including indicators of cytolysis and bilirubin. Finally, the third trial was performed to quantify the effect of lower GLs doses on growth.

Results

The extreme GLs dose caused a decrease in hepatic fat deposition and growth, in line with microarray findings, which suggested tissue remodeling and reduction of cellular proliferation in the skeletal muscle and liver. Lower GLs inclusion levels in a follow-up trial did not show negative effects on growth. Microarray analysis of the distal kidney pointed to activation of anti-fibrotic responses under the overexposure. However, analyses of ALT, CK and AST enzymes in plasma provided no evidence of increased cytolysis and organ damage. Prevalent activation of phase-2 detoxification genes that occurred in all three tissues could be considered part of beneficial effects caused by the extreme dose of GLs. In addition, transcriptomic evidence suggested GLs-mediated iron and heme withdrawal response, including increased heme degradation in muscle (upregulation of heme oxygenase-1), decrease of its synthesis in liver (downregulation of porphobilinogen deaminase) and increased iron sequestration from blood (hepatic induction of hepcidin-1 and renal induction of intracellular storage protein ferritin). This response could be advantageous for salmon upon encountering lice, which depend on the host for the provision of iron carrying heme. Most of the hepatic genes studied by qPCR showed similar expression levels in fish exposed to GLs, lice and their combination, while renal induction of leptin suggested heightened stress by the combination of extreme dose of GLs and lice. High expression of interferonγ (cytokine considered organ-protective in mammalian kidney) was detected at the moderate GLs level. This fish also showed highest plasma bilirubin levels (degradation product of heme), and had lowest number of attached lice, further supporting hypothesis that making heme unavailable to lice could be part of an effective anti-parasitic strategy.

Conclusions

Modulation of detoxification and iron metabolism in Atlantic salmon tissues could be beneficial prior and during lice infestations. Investigation of anti-lice functional feeds based on low and moderate GLs inclusion levels thus deserves further attention.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1921-7) contains supplementary material, which is available to authorized users.

Glucosinolates profile, volatile constituents, antimicrobial, and cytotoxic activities of Lobularia libyca

CONTEXT

Brassicaceae plants are associated with protection against cancers due to their glucosinolate contents.

OBJECTIVES

We investigate fresh leaves, roots and ripe seeds of Lobularia libyca (Viv.) C.F.W. Meissn. (Brassicaceae) to identify their glucosinolate constituents, antimicrobial and cytotoxic activities Materials and methods: The glucosinolates were identified using GC-MS analysis of their hydrolysis products and LC-MS analysis in the case of seeds. Disc diffusion (1 mg/disc) and minimum inhibitory concentration (0-160 μg/mL) methods were used to evaluate the antimicrobial activity of seed hydrolysate. In vitro cytotoxicity against colorectal HCT-116, hepatic HUH-7, breast MCF-7 and lung A-549 cells was evaluated for seed hydrolysate (0.01-100 μg/mL) using the sulforhodamine B assay and doxorubicin as a standard Results: Three glucosinolates were identified for the first time in this plant and genus Lobularia. Glucoiberverin was the major compound accumulated in the seeds and leaves, while glucoiberin and glucoerucin were detected only in the seeds. No glucosinolates were detected in roots under the same experimental conditions. Other volatile constituents, e.g., terpenes and fatty acids were only identified in the seeds. The seed hydrolysate showed significant antimicrobial activities against Candida albicans and Pseudomonas aeruoginosa (MIC = 64 and 82 μg/mL, respectively). The seed hydrolysate exhibited a marked selective cytotoxicity in vitro against colorectal, hepatic and breast cancer cell lines. The IC₅₀ values were 0.31, 2.25 and 37 μg/mL, respectively.

DISCUSSION AND CONCLUSION

The results indicated the antimicrobial activity of L. libyca and the selective effect of the seed hydrolysate as a cytotoxic drug that is potentially more active than doxorubicin against HCT-116.

Cytotoxic and genotoxic potential of food-borne nitriles in a liver in vitro model

Isothiocyanates are the most intensively studied breakdown products of glucosinolates from Brassica plants and well recognized for their pleiotropic effects against cancer but also for their genotoxic potential. However, knowledge about the bioactivity of glucosinolate-borne nitriles in foods is very poor. As determined by GC-MS, broccoli glucosinolates mainly degrade to nitriles as breakdown products. The cytotoxicity of nitriles in human HepG2 cells and primary murine hepatocytes was marginal as compared to isothiocyanates. Toxicity of nitriles was not enhanced in CYP2E1-overexpressing HepG2 cells. In contrast, the genotoxic potential of nitriles was found to be comparable to isothiocyanates. DNA damage was persistent over a certain time period and CYP2E1-overexpression further increased the genotoxic potential of the nitriles. Based on actual in vitro data, no indications are given that food-borne nitriles could be relevant for cancer prevention, but could pose a certain genotoxic risk under conditions relevant for food consumption.

Reaction of zearalenone and α-zearalenol with allyl isothiocyanate, characterization of reaction products, their bioaccessibility and bioavailability in vitro

This study investigates the reduction of zearalenone (ZEA) and α-zearalenol (α-ZOL) on a solution model using allyl isothiocyanate (AITC) and also determines the bioaccessibility and bioavailability of the reaction products isolated and identified by MS-LIT. Mycotoxin reductions were dose-dependent, and ZEA levels decreased more than α-ZOL, ranging from 0.2 to 96.9% and 0 to 89.5% respectively, with no difference (p⩽0.05) between pH 4 and 7. Overall, simulated gastric bioaccessibility was higher than duodenal bioaccessibility for both mycotoxins and mycotoxin-AITC conjugates, with duodenal fractions representing ⩾63.5% of the original concentration. Simulated bioavailability of reaction products (α-ZOL/ZEA-AITC) were lower than 42.13%, but significantly higher than the original mycotoxins. The cytotoxicity of α-ZOL and ZEA in Caco-2/TC7 cells was also evaluated, with toxic effects observed at higher levels than 75μM. Further studies should be performed to evaluate the toxicity and estrogenic effect of α-ZOL/ZEA-AITC.

The Isothiocyanate Isolated from Moringa oleifera Shows Potent Anti-Inflammatory Activity in the Treatment of Murine Subacute Parkinson's Disease

The present study was aimed at estimating a possible neuroprotective effect of glucomoringin (GMG) [4-(α-L-rhamnopyranosyloxy)benzyl glucosinolate] bioactivated with the enzyme myrosinase to form the corresponding isothiocyanate [4-(α-L-rhamnopyranosyloxy)benzyl C; moringin] in the treatment or prevention of Parkinson's disease (PD). In this study, the beneficial effects of moringin were compared with those of pure GMG, not enzymatically activated, in an in vivo experimental mouse model of subacute PD. Subacute PD was induced in C57BL/6 mice by administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Mice were pretreated daily for 1 week with moringin (10 mg/kg +5 μL myrosinase/mouse) and with GMG (10 mg/kg). Behavioral evaluations were also performed to assess motor deficits and bradykinesia in MPTP mice. Besides, assuming that pretreatment with moringin could modulate the triggering of inflammatory cascade with a correlated response, we tested its in vitro anti-inflammatory activity by using a model of RAW 264.7 macrophages stimulated with lipopolysaccharide. Achieved results in vivo showed a higher efficacy of moringin compared with GMG not only to modulate the inflammatory pathway but also oxidative stress and apoptotic pathways. In addition, the greater effectiveness of moringin in countering mainly the inflammatory pathway has been corroborated by the results obtained in vitro. The relevance and innovation of the present study lie in the possible use of a safe formulation of a bioactive compound, resulting from exogenous myrosinase hydrolysis of the natural phytochemical GMG, which can be used in clinical practice as a useful drug for the treatment or prevention of PD.

The Role of Glucosinolate Hydrolysis Products from Brassica Vegetable Consumption in Inducing Antioxidant Activity and Reducing Cancer Incidence

The bioactivity of glucosinolates (GSs), and more specifically their hydrolysis products (GSHPs), has been well documented. These secondary metabolites evolved in the order Brassicales as plant defense compounds with proven ability to deter or impede the growth of several biotic challenges including insect infestation, fungal and bacterial infection, and competition from other plants. However, the bioactivity of GSHPs is not limited to activity that inhibits these kingdoms of life. Many of these compounds have been shown to have bioactivity in mammalian systems as well, with epidemiological links to cancer chemoprevention in humans supported by in vitro, in vivo, and small clinical studies. Although other chemopreventive mechanisms have been identified, the primary mechanism believed to be responsible for the observed chemoprevention from GSHPs is the induction of antioxidant enzymes, such as NAD(P)H quinone reductase (NQO1), heme oxygenase 1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutathione S transferases (GSTs), through the Keap1-Nrf2-ARE signaling pathway. Induction of this pathway is generally associated with aliphatic isothiocyanate GSHPs, although some indole-derived GSHPs have also been associated with induction of one or more of these enzymes.

Dietary phytochemicals modulate skin gene expression profiles and result in reduced lice counts after experimental infection in Atlantic salmon

Background

The use of phytochemicals is a promising solution in biological control against salmon louse (Lepeophtheirus salmonis). Glucosinolates belong to a diverse group of compounds used as protection against herbivores by plants in the family Brassicaceae, while in vertebrates, ingested glucosinolates exert health-promoting effects due to their antioxidant and detoxifying properties as well as effects on cell proliferation and growth. The aim of this study was to investigate if Atlantic salmon fed two different doses of glucosinolate-enriched feeds would be protected against lice infection. The effects of feeding high dose of glucosinolates before the infection, and of high and low doses five weeks into the infection were studied.

Methods

Skin was screened by 15 k oligonucleotide microarray and qPCR.

Results

A 25 % reduction (P < 0.05) in lice counts was obtained in the low dose group and a 17 % reduction in the high dose group compared to fish fed control feed. Microarray analysis revealed induction of over 50 interferon (IFN)-related genes prior to lice infection. Genes upregulated five weeks into the infection in glucosinolate-enriched dietary groups included Type 1 pro-inflammatory factors, antimicrobial and acute phase proteins, extracellular matrix remodeling proteases and iron homeostasis regulators. In contrast, genes involved in muscle contraction, lipid and glucose metabolism were found more highly expressed in the skin of infected control fish.

Conclusions

Atlantic salmon fed glucosinolates had a significantly lower number of sea lice at the end of the experimental challenge. Feeding glucosinolates coincided with increased expression of IFN-related genes, and higher expression profiles of Type 1 immune genes late into the infection. In addition, regulation of genes involved in the metabolism of iron, lipid and sugar suggested an interplay between metabolism of nutrients and mechanisms of resistance.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1537-y) contains supplementary material, which is available to authorized users.

Iron depletion in HCT116 cells diminishes the upregulatory effect of phenethyl isothiocyanate on heme oxygenase-1

Some of the health-promoting properties of cruciferous vegetables are thought to be partly attributed to isothiocyanates. These phytochemicals can upregulate the expression of certain cytoprotective stress genes, but it is unknown if a particular nutrient is involved. Herein, the objective was to ascertain if adequate iron is needed for enabling HCT116 cells to optimally express heme oxygenase-1 (HO-1) when induced by phenethyl isothiocyanate (PEITC). PEITC increased HO-1 expression and also nuclear translocation of Nrf2, which is a transcription factor known to activate the HO-1 gene. However, in HCT116 cells that were made iron-deficient by depleting intracellular iron with deferoxamine (DFO), PEITC was less able to increase HO-1 expression and nuclear translocation of Nrf2. These suppressive effects of DFO were overcome by replenishing the iron-deficient cells with the missing iron. To elucidate these findings, it was found that PEITC-induced HO-1 upregulation can be inhibited with thiol antioxidants (glutathione and N-acetylcysteine). Furthermore, NADPH oxidase inhibitors (diphenyleneiodonium and apocynin) and a superoxide scavenger (Tiron) each inhibited PEITC-induced HO-1 upregulation. In doing so, diphenyleneiodonium was the most potent and also inhibited nuclear translocation of redox-sensitive Nrf2. Collectively, the results imply that the HO-1 upregulation by PEITC involves an iron-dependent, oxidant signaling pathway. Therefore, it is concluded that ample iron is required to enable PEITC to fully upregulate HO-1 expression in HCT116 cells. As such, it is conceivable that iron-deficient individuals may not reap the full health benefits of eating PEITC-containing cruciferous vegetables that via HO-1 may help protect against multiple chronic diseases.

Broad targeting of resistance to apoptosis in cancer

Apoptosis or programmed cell death is natural way of removing aged cells from the body. Most of the anti-cancer therapies trigger apoptosis induction and related cell death networks to eliminate malignant cells. However, in cancer, de-regulated apoptotic signaling, particularly the activation of an anti-apoptotic systems, allows cancer cells to escape this program leading to uncontrolled proliferation resulting in tumor survival, therapeutic resistance and recurrence of cancer. This resistance is a complicated phenomenon that emanates from the interactions of various molecules and signaling pathways. In this comprehensive review we discuss the various factors contributing to apoptosis resistance in cancers. The key resistance targets that are discussed include (1) Bcl-2 and Mcl-1 proteins; (2) autophagy processes; (3) necrosis and necroptosis; (4) heat shock protein signaling; (5) the proteasome pathway; (6) epigenetic mechanisms; and (7) aberrant nuclear export signaling. The shortcomings of current therapeutic modalities are highlighted and a broad spectrum strategy using approaches including (a) gossypol; (b) epigallocatechin-3-gallate; (c) UMI-77 (d) triptolide and (e) selinexor that can be used to overcome cell death resistance is presented. This review provides a roadmap for the design of successful anti-cancer strategies that overcome resistance to apoptosis for better therapeutic outcome in patients with cancer.

No association between adherence to the healthy Nordic food index and cardiovascular disease amongst Swedish women: a cohort study

BACKGROUND

In several intervention trials, a healthy Nordic diet showed beneficial effects on markers of cardiovascular disease. We investigated the association between a healthy Nordic diet and clinical diagnosis of cardiovascular disease.

OBJECTIVE

Our aim was first to examine the association between a healthy Nordic food index (wholegrain bread, oatmeal, apples/pears, root vegetables, cabbages and fish) and the incidence of overall cardiovascular disease (ischaemic heart disease, stroke, arrhythmia, thrombosis and hypertensive disease), and secondly to test for possible effect modification by smoking, body mass index (BMI), alcohol consumption and age.

METHODS

We conducted an analysis of data from the prospective Swedish Women's Lifestyle and Health cohort, including 43 310 women who completed a food frequency questionnaire in 1991-1992, and followed up until 31 December 2012 through Swedish registries. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards models.

RESULTS

During follow-up, 8383 women developed cardiovascular disease. We found no association between the healthy Nordic food index and overall cardiovascular disease risk or any of the subgroups investigated. There was a statistically significant interaction with smoking status (P = 0.02), with a beneficial effect only amongst former smokers (HR 0.96, 95% CI 0.94-0.99 per 1-point increment).

CONCLUSION

The present results do not support an association between a healthy Nordic food index and risk of cardiovascular disease in Swedish women. There was also no effect modification by alcohol intake, BMI or age. Our finding of an interaction with smoking status requires reproduction.

Optimization of extraction, characterization and antioxidant activity of polysaccharides from Brassica rapa L

The root of Brassica rapa L. has been traditionally used as a Uyghur folk medicine to cure cough and asthma by Uyghur nationality in Xinjiang Uygur Autonomous Region of China. In the present study, therefore, extraction optimization, characterization and antioxidant activity in vitro of polysaccharides from the root of B. rapa L. (BRP) were investigated. The optimal extraction conditions with an extraction yield of 21.48 ± 0.41% for crude BRP were obtained as follows: extraction temperature 93°C, extraction time 4.3h and ratio of extraction solvent (water) to raw material 75 mL/g. The crude BRP was purified by chromatographic columns of DEAE-52 cellulose and Sephadex G-100, affording three purified fractions of BRP-1-1, BRP-2-1 and BRP-2-2 with average molecular weight of 1510, 1110 and 838 kDa, respectively. Monosaccharide composition analysis indicated that BRP-1-1 was composed of mannose, rhamnose, glucose, galactose and arabinose, BRP-2-1 was composed of rhamnose, galacturonic acid, galactose and arabinose, and BRP-2-2 was composed of rhamnose and galacturonic acid in a molar ratio of 1.27: 54.92. Furthermore, the crude BRP exhibited relatively higher antioxidant activity in vitro than purified fractions; hence, it could be used as a natural antioxidant in functional foods or medicines.

Pharmacokinetics, Tissue Distribution, and Anti-Lipogenic/Adipogenic Effects of Allyl-Isothiocyanate Metabolites

Allyl-isothiocyanate (AITC) is an organosulfur phytochemical found in abundance in common cruciferous vegetables such as mustard, wasabi, and cabbage. Although AITC is metabolized primarily through the mercapturic acid pathway, its exact pharmacokinetics remains undefined and the biological function of AITC metabolites is still largely unknown. In this study, we evaluated the inhibitory effects of AITC metabolites on lipid accumulation in vitro and elucidated the pharmacokinetics and tissue distribution of AITC metabolites in rats. We found that AITC metabolites generally conjugate with glutathione (GSH) or N-acetylcysteine (NAC) and are distributed in most organs and tissues. Pharmacokinetic analysis showed a rapid uptake and complete metabolism of AITC following oral administration to rats. Although AITC has been reported to exhibit anti-tumor activity in bladder cancer, the potential bioactivity of its metabolites has not been explored. We found that GSH-AITC and NAC-AITC effectively inhibit adipogenic differentiation of 3T3-L1 preadipocytes and suppress expression of PPAR-γ, C/EBPα, and FAS, which are up-regulated during adipogenesis. GSH-AITC and NAC-AITC also suppressed oleic acid-induced lipid accumulation and lipogenesis in hepatocytes. Our findings suggest that AITC is almost completely metabolized in the liver and rapidly excreted in urine through the mercapturic acid pathway following administration in rats. AITC metabolites may exert anti-obesity effects through suppression of adipogenesis or lipogenesis.