Efficacy of sulforaphane in eradicating Helicobacter pylori in human gastric xenografts implanted in nude mice

Phytochemicals and Their Usefulness in the Maintenance of Health

Inflammation is the immune system's first biological response to infection, injury, or irritation. Evidence suggests that the anti-inflammatory effect is mediated by the regulation of various inflammatory cytokines, such as nitric oxide, interleukins, tumor necrosis factor alpha-α, interferon gamma-γ, as well as the non-cytokine mediator, prostaglandin E2. Currently, the mechanism of action and clinical usefulness of phytochemicals is known; their action on the activity of cytokines, free radicals, and oxidative stress. The latter are of great relevance in the development of diseases, such that the evidence collected demonstrates the beneficial effects of phytochemicals in maintaining health. Epidemiological evidence indicates that regular consumption of fruits and vegetables is related to a low risk of developing cancer and other chronic diseases.

Natural foods resources and dietary ingredients for the amelioration of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a gastric-persistent pathogen that can cause peptic ulcer disease, gastric cancer, and mucosal-associated lymphoid tissue lymphoma. This pathogen is commonly treated with antibiotic-based triple or quadruple therapy. However, antibiotic therapy could result in the bacterial resistance, imbalance of gut microbiota, and damage to the liver and kidneys, etc. Therefore, there is an urgent need for alternative therapeutic strategies. Interestingly, natural food resources, like vegetables, fruits, spices, and edible herbs, have potent inhibitory effects on H. pylori. In this review, we systematically summarized these foods with supporting evidence from both animal and clinical studies. The results have indicated that natural foods may possess temporary inhibition effect on H. pylori rather than durable eradication, and may help to reduce H. pylori colonization, enhance the effect of antibiotics and modulate the host's immune response.

Effects of Sulforaphane on SARS‑CoV‑2 infection and NF‑κB dependent expression of genes involved in the COVID‑19 'cytokine storm'

Since its spread at the beginning of 2020, the coronavirus disease 2019 (COVID‑19) pandemic represents one of the major health problems. Despite the approval, testing, and worldwide distribution of anti‑severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) vaccines, the development of specific antiviral agents targeting the SARS‑CoV‑2 life cycle with high efficiency, and/or interfering with the associated 'cytokine storm', is highly required. A recent study, conducted by the authors' group indicated that sulforaphane (SFN) inhibits the expression of IL‑6 and IL‑8 genes induced by the treatment of IB3‑1 bronchial cells with a recombinant spike protein of SARS‑CoV‑2. In the present study, the ability of SFN to inhibit SARS‑CoV‑2 replication and the expression of pro‑inflammatory genes encoding proteins of the COVID‑19 'cytokine storm' was evaluated. SARS‑CoV‑2 replication was assessed in bronchial epithelial Calu‑3 cells. Moreover, SARS‑CoV‑2 replication and expression of pro‑inflammatory genes was evaluated by reverse transcription quantitative droplet digital PCR. The effects on the expression levels of NF‑κB were assessed by western blotting. Molecular dynamics simulations of NF‑kB/SFN interactions were conducted with Gromacs 2021.1 software under the Martini 2 CG force field. Computational studies indicated that i) SFN was stably bound with the NF‑κB monomer; ii) a ternary NF‑kB/SFN/DNA complex was formed; iii) the SFN interacted with both the protein and the nucleic acid molecules modifying the binding mode of the latter, and impairing the full interaction between the NF‑κB protein and the DNA molecule. This finally stabilized the inactive complex. Molecular studies demonstrated that SFN i) inhibits the SARS‑CoV‑2 replication in infected Calu‑3 cells, decreasing the production of the N‑protein coding RNA sequences, ii) decreased NF‑κB content in SARS‑CoV‑2 infected cells and inhibited the expression of NF‑kB‑dependent IL‑1β and IL‑8 gene expression. The data obtained in the present study demonstrated inhibitory effects of SFN on the SARS‑CoV‑2 life cycle and on the expression levels of the pro‑inflammatory genes, sustaining the possible use of SFN in the management of patients with COVID‑19.

Glucosinolates, a natural chemical arsenal: More to tell than the myrosinase story

Glucosinolates are a group of thioglucosides that belong to the class of plant nitrogen-containing natural products. So far, very little biological activity has been associated with intact glucosinolates. The hydrolysis of glucosinolates has, for long, attracted attention because of the potent biological activity of the hydrolysis products. From allelopathic to antiparasitic, antimicrobial and antineoplastic effects, the activity spectrum of the degradation products of typical glucosinolates has been the subject of much research. The present review seeks to address the various means of glucosinolate degradation (thermal, enzymatic, or chemical degradation) and the ensuing products. It also aims to draw a comparative profile of the various antimicrobial effects of these degradation products to provide a further understanding of the biological function of these important compounds.

Low Expression of TSTD2 Serves as a Biomarker for Poor Prognosis in Kidney Renal Clear Cell Carcinoma

Introduction

Kidney renal clear cell carcinoma (KIRC) is a common cancer in people worldwide, and one of the main issues is developing suitable biomarkers. This study aims to investigate the expression of TSTD2 in KIRC and its impact on prognosis.

Methods

RNA sequencing data from TCGA and GTEx were gathered to examine the functional enrichment of TSTD2-related differentially expressed genes (DEGs) using GO/KEGG, GSEA, immunocyte permeation analysis, and protein-protein interaction (PPI) network analysis. The Kaplan‒Meier-Cox regression model and the prognostic nomograph model were used to assess the clinical importance of TSTD2 in KIRC. R software was used to analyze the included studies. Finally, verification of cells and tissues was performed using immunohistochemical staining and quantitative real‒time PCR.

Results

In contrast to normal samples, it was discovered that TSTD2 was underexpressed in a number of malignancies, including KIRC. Furthermore, in 163 KIRC samples, low expression of TSTD2 was linked to a poor prognosis, as were subgroups with age greater than 60, the integrin pathway, the development of elastic fibers, and high TNM stage, pathologic stage, and histologic grade (P < 0.05). Age and TNM stage were included in the nomogram prognostic model, and low TSTD2 was a prognostic predictor that could be used independently in Cox regression analysis. In addition, 408 DEGs with 111 upregulated genes and 297 downregulated genes were found between the high- and low-expression groups.

Conclusion

The diminished expression of TSTD2 may serve as a biomarker for unfavorable outcomes in KIRC, and holds potential as a target for therapeutic interventions.

In Silico and In Vitro Analysis of Sulforaphane Anti-Candida Activity

Oropharyngeal candidiasis/candidosis is a common and recurrent opportunistic fungal infection. Fluconazole (FLZ), one of the most used and effective antifungal agents, has been associated with a rise of resistant Candida species in immunocompromised patients undergoing prophylactic therapy. Sulforaphane (SFN), a compound from cruciferous vegetables, is an antimicrobial with yet controversial activities and mechanisms on fungi. Herein, the in silico and antifungal activities of SFN against C. albicans were investigated. In silico analyzes for the prediction of the biological activities and oral bioavailability of SFN, its possible toxicity and pharmacokinetic parameters, as well as the estimates of its gastrointestinal absorption, permeability to the blood-brain barrier and skin, and similarities to drugs, were performed by using different software. SFN in vitro anti-Candida activities alone and in combination with fluconazole (FLZ) were determined by the broth microdilution method and the checkerboard, biofilm and hyphae formation tests. Amongst the identified probable biological activities of SFN, nine indicated an antimicrobial potential. SFN was predicted to be highly absorbable by the gastrointestinal tract, to present good oral availability, and not to be irritant and/or hepatotoxic. SFN presented antifungal activity against C. albicans and prevented both biofilm and hyphae formation by this microorganism. SFN was additive/synergistic to FLZ. Overall, the data highlights the anti-Candida activity of SFN and its potential to be used as an adjuvant therapy to FLZ in clinical settings.

Glucosinolates and Omega-3 Fatty Acids from Mustard Seeds: Phytochemistry and Pharmacology

Seeds from mustard (genera Brassica spp. and Sinapsis spp.), are known as a rich source of glucosinolates and omega-3 fatty acids. These compounds are widely known for their health benefits that include reducing inflammation and lowering the risk of cardiovascular diseases and cancer. This review presented a synthesis of published literature from Google Scholar, PubMed, Scopus, Sci Finder, and Web of Science regarding the different glucosinolates and omega-3 fatty acids isolated from mustard seeds. We presented an overview of extraction, isolation, purification, and structure elucidation of glucosinolates from the seeds of mustard plants. Moreover, we presented a compilation of in vitro, in vivo, and clinical studies showing the potential health benefits of glucosinolates and omega-3 fatty acids. Previous studies showed that glucosinolates have antimicrobial, antipain, and anticancer properties while omega-3 fatty acids are useful for their pharmacologic effects against sleep disorders, anxiety, cerebrovascular disease, neurodegenerative disease, hypercholesterolemia, and diabetes. Further studies are needed to investigate other naturally occurring glucosinolates and omega-3 fatty acids, improve and standardize the extraction and isolation methods from mustard seeds, and obtain more clinical evidence on the pharmacological applications of glucosinolates and omega-3 fatty acids from mustard seeds.

The effects of the dietary compound L-sulforaphane against respiratory pathogens

L-sulforaphane (LSF) is an isothiocyanate derived from cruciferous vegetables that has long been known for its anticarcinogenic, antioxidant and anti-inflammatory effects. LSF also possesses antimicrobial properties, although the evidence for this is limited. Respiratory pathogens, such as Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes and respiratory syncytial virus (RSV), are leading global causes of illness and death among children aged under five years, particularly in resource-poor countries where access to vaccines are limited or, in the case of S. pyogenes and RSV, vaccines have not been licensed for use in humans. Therefore, alternative strategies to prevent and/or treat these common infectious diseases are urgently needed. This study was conducted to investigate the antimicrobial effects of LSF against common respiratory pathogens, S. pneumoniae (serotypes 1 and 6B), H. influenzae type B (HiB), non-typeable H. influenzae (NTHi), S. pyogenes and RSV in relevant human cell-based models. LSF significantly inhibited the growth of H. influenzae, but not S. pneumoniae or S. pyogenes. LSF did not improve opsonophagocytic capacity or killing by human phagocytic cell lines (HL-60s and THP-1 macrophages) for S. pneumoniae yet showed some improved killing for H. influenzae species in THP-1 macrophages. However, LSF significantly reduced RSV infection in human lung epithelial cells, associated with increased expression of cyclin D1 (CCND1) gene as well as the antioxidant genes, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HMOX-1). Overall, LSF represents an exciting avenue for further antimicrobial research, particularly as a novel therapy against H. influenzae species and RSV.

Antibiotics: Conventional Therapy and Natural Compounds with Antibacterial Activity-A Pharmaco-Toxicological Screening

Antibiotics are considered as a cornerstone of modern medicine and their discovery offers the resolution to the infectious diseases problem. However, the excessive use of antibiotics worldwide has generated a critical public health issue and the bacterial resistance correlated with antibiotics inefficiency is still unsolved. Finding novel therapeutic approaches to overcome bacterial resistance is imperative, and natural compounds with antibacterial effects could be considered a promising option. The role played by antibiotics in tumorigenesis and their interrelation with the microbiota are still debatable and are far from being elucidated. Thus, the present manuscript offers a global perspective on antibiotics in terms of evolution from a historical perspective with an emphasis on the main classes of antibiotics and their adverse effects. It also highlights the connection between antibiotics and microbiota, focusing on the dual role played by antibiotics in tumorigenesis. In addition, using the natural compounds with antibacterial properties as potential alternatives for the classical antibiotic therapy is discussed.

Health Benefits of Plant-Derived Sulfur Compounds, Glucosinolates, and Organosulfur Compounds

The broad spectrum of the mechanism of action of immune-boosting natural compounds as well as the complex nature of the food matrices make researching the health benefits of various food products a complicated task. Moreover, many routes are involved in the action of most natural compounds that lead to the inhibition of chronic inflammation, which results in a decrease in the ability to remove a pathogen asymptomatically and is connected to various pathological events, such as cancer. A number of cancers have been associated with inflammatory processes. The current review strives to answer the question of whether plant-derived sulfur compounds could be beneficial in cancer prevention and therapy. This review focuses on the two main sources of natural sulfur compounds: alliaceous and cruciferous vegetables. Through the presentation of scientific data which deal with the study of the chosen compounds in cancer (cell lines, animal models, and human studies), the discussion of food processing’s influence on immune-boosting food content is presented. Additionally, it is demonstrated that there is still a need to precisely demonstrate the bioavailability of sulfur-containing compounds from various types of functional food, since the inappropriate preparation of vegetables can significantly reduce the content of beneficial sulfur compounds. Additionally, there is an urgent need to carry out more epidemiological studies to reveal the benefits of several natural compounds in cancer prevention and therapy.

Sulforaphane-enriched extracts from glucoraphanin-rich broccoli exert antimicrobial activity against gut pathogens in vitro and innovative cooking methods increase in vivo intestinal delivery of sulforaphane

Purpose

Studies on broccoli (Brassica oleracea var. italica) indicate beneficial effects against a range of chronic diseases, commonly attributed to their bioactive phytochemicals. Sulforaphane, the bioactive form of glucoraphanin, is formed by the action of the indigenous enzyme myrosinase. This study explored the role that digestion and cooking practices play in bioactivity and bioavailability, especially the rarely considered dose delivered to the colon.

Methods

The antimicrobial activity of sulforaphane extracts from raw, cooked broccoli and cooked broccoli plus mustard seeds (as a source myrosinase) was assessed. The persistence of broccoli phytochemicals in the upper gastrointestinal tract was analysed in the ileal fluid of 11 ileostomates fed, in a cross-over design, broccoli soup prepared with and without mustard seeds.

Results

The raw broccoli had no antimicrobial activity, except against Bacillus cereus, but cooked broccoli (with and without mustard seeds) showed considerable antimicrobial activity against various tested pathogens. The recovery of sulforaphane in ileal fluids post soup consumption was < 1% but the addition of mustard seeds increased colon-available sulforaphane sixfold. However, when sulforaphane was extracted from the ileal fluid with the highest sulforaphane content and tested against Escherichia coli K12, no inhibitory effects were observed. Analysis of glucosinolates composition in ileal fluids revealed noticeable inter-individual differences, with six “responding” participants showing increases in glucosinolates after broccoli soup consumption.

Conclusions

Sulforaphane-rich broccoli extracts caused potent antimicrobial effects in vitro, and the consumption of sulforaphane-enriched broccoli soup may inhibit bacterial growth in the stomach and upper small intestine, but not in the terminal ileum or the colon.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02322-0) contains supplementary material, which is available to authorized users.

Sulforaphane promotes chlamydial infection by suppressing mitochondrial protein oxidation and activation of complement C3

Sulforaphane (SFN), a phytochemical found in broccoli and other cruciferous vegetables, is a potent antioxidant and anti-inflammatory agent with reported effects in cancer chemoprevention and suppression of infection with intracellular pathogens. Here we report on the impact of SFN on infection with Chlamydia trachomatis (Ct), a common sexually transmitted pathogen responsible for 131 million new cases annually worldwide. Astoundingly, we find that SFN as well as broccoli sprouts extract (BSE) promote Ct infection of human host cells. Both the number and size of Ct inclusions were increased when host cells were pretreated with SFN or BSE. The initial investigations presented here point to both the antioxidant and thiol alkylating properties of SFN as regulators of Ct infection. SFN decreased mitochondrial protein sulfenylation and promoted Ct development, which were both reversed by treatment with mitochondria-targeted paraquat (MitoPQ). Inhibition of the complement component 3 (complement C3) by SFN was also identified as a mechanism by which SFN promotes Ct infections. Mass spectrometry analysis found alkylation of cysteine 1010 (Cys1010) in complement C3 by SFN. The studies reported here raise awareness of the Ct infection promoting activity of SFN, and also identify potential mechanisms underlying this activity.

Various modes of action of dietary phytochemicals, sulforaphane and phenethyl isothiocyanate, on pathogenic bacteria

Isothiocyanates (ITCs) derived from cruciferous plants reveal antibacterial activity, although detailed mechanism is not fully elucidated. Recently it has been reported that ITCs induce the stringent response in Escherichia coli strains. The aim of this work was to determine whether two isothiocyanates, sulforaphane (SFN) and phenethyl isothiocyanate (PEITC), similarly as in E. coli induce stringent response in Bacillus subtilis, model Gram(+) bacterium, and test their potency against a panel of clinical isolates belonging to Gram(+) or Gram(-) groups. Minimal inhibitory concentrations were determined as well as effect of ITCs on membranes integrity, synthesis of DNA, RNA and stringent response alarmones was assessed. SFN and PEITC are effective against B. subtilis and bacterial isolates, namely E. coli, K. pneumonia, S. aureus, S. epidermidis and E. faecalis. Interestingly, in B. subtilis and E. faecalis the inhibition of growth and nucleic acids synthesis is independent of ppGpp accumulation. In bacteria, which do not induce the stringent response in the presence of ITCs, membrane integrity disruption is observed. Thus, ITCs are effective against different pathogenic bacteria and act by at least two mechanisms depending on bacteria species.

Isothiocyanates: An Overview of Their Antimicrobial Activity against Human Infections

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

Biosynthesis and bioactivity of glucosinolates and their production in plant in vitro cultures

Glucosinolates are biologically active compounds which are involved in plant defense reaction. The use of plant in vitro cultures and genetic engineering is a promising strategy for their sustainable production. Glucosinolates are a class of secondary metabolites found mainly in Brassicaceae, which contain nitrogen and sulfur in their structures. Glucosinolates are divided into three groups depending on the amino acid from which they are biosynthesized. Aliphatic glucosinolates are generally derived from leucine, valine, methionine, isoleucine and alanine while indole and aromatic glucosinolates are derived from tryptophan and phenylalanine or tyrosine, respectively. These compounds are hydrolyzed by the enzyme myrosinase when plants are stressed by biotic and abiotic factors, obtaining different degradation products. Glucosinolates and their hydrolysis products play an important role in plant defense responses against different types of stresses. In addition, these compounds have beneficial effect on human health because they are strong antioxidants and they have potent cardiovascular, antidiabetic, antimicrobial and antitumoral activities. Due to all the properties described above, the demand for glucosinolates and their hydrolysis products has enormously increased, and therefore, new strategies that allow the production of these compounds to be improved are needed. The use of plant in vitro cultures is emerging as a biotechnological strategy to obtain glucosinolates and their derivatives. This work is focused on the biosynthesis of glucosinolates and the bioactivity of these compounds in plants. In addition, a detailed study on the strategies used to increase the production of several glucosinolates, in particular those synthesized in Brassicaceae, using in vitro plant cultures has been made. Special attention has been paid for increasing the production of glucosinolates and their derivatives using metabolic engineering.

Functional foods and their role in cancer prevention and health promotion: a comprehensive review

Following cardiovascular disease, cancer is the second leading cause of death in most affluent countries. The 13.3 million new cases of cancer in 2010 were predicted to cost US$ 290 billion, but the total costs were expected to increases to US$ 458 billion in the year 2030 on basis of World Economic Forum in 2011. More than half of all cancer cases and deaths worldwide are consider being preventable. From its inception, the disease control priorities series has focused attention on delivering efficacious health interventions that can result in dramatic reductions in mortality and disability at relatively modest cost. The approach has been multidisciplinary, and the recommendations have been evidence-based, scalable, and adaptable in multiple settings. Better and more equitable health care is the shared responsibility of governments and international agencies, public and private sectors, and societies and individuals, and all of these partners have been involved in the development of the series. Functional foods are foods and food components that supply health benefits beyond basic nutrition. It's-believed these functional foods do more than simply provide nutrients because they help to maintaining health and thereby reducing the risk of disease. There are some reported evidences showing association between functional foods and cancer. For example, S-ally cysteine of garlic and lycopene from tomatoes in combination form suppressed the development of chemically induced gastric cancer by modulation of apoptosis-associated proteins (reduced Bcl-2/Bax ratio and up-regulation of Bim and caspases 8 and 3) at considerably lower intakes than when these substances were given in isolation. Similarly, vitamin D3 with genistein in combination form precipitated a growth inhibition of prostate cancer cells at much lower concentration than when these substances were provided individually. There are very few studies conducted worldwide to see the effects of functional foods on health or cancer or related states. This review, presents the complex patterns of cancer incidence and death around the world and evidence on effective and cost-effective ways to control cancers. The evaluation of cancer will indicate where cancer treatment is ineffective and wasteful, and offer alternative cancer care packages that are cost-effective and suited to low-resource settings. In the present paper, cancer prevention by functional foods is reviewed and the possible mechanisms of action are described.

Role of Sulforaphane in Protection of Gastrointestinal Tract Against H. pylori and NSAID-Induced Oxidative Stress

BACKGROUND

Sulforaphane (SFN), a phytochemical found in abundance in broccoli sprouts, potently induces a variety of antioxidant enzymes, and thereby protects cells from injury induced by various kinds of oxidative stresses. It has been suggested that both H. pylori infection and intake of non-steroidal anti-inflammatory drugs (NSAIDs) induce chronic oxidative stress in gastrointestinal (GI) mucosa, thereby causing mucosal injury in the GI tract. Therefore, it would be a reasonable assumption that SFN protects GI mucosa against oxidative injury induced by H. pylori or NSAIDs.

METHODS

We examined the effects of SFN on H. pylori viability in vitro, levels of gastritis in H.pylori-infected mice in vivo, and in H.pylori-infected human subjects. We also examined the effects of SFN on NSAID-induced small intestinal injury in mice.

RESULTS

Our data from the H. pylori infection study clearly demonstrated that SFN inhibited H. pylori viability both in vitro and in vivo, and mitigated H. pylori-induced gastritis in mice and humans. Similarly, our study on NSAID-induced small intestinal injury showed that SFN not only mitigated aspirin-induced injury of small intestinal epithelial cells in vitro, but also ameliorated indomethacin-induced small intestinal injury in mice in vivo.

CONCLUSIONS

These data strongly suggest that SFN contributes to the protection of GI mucosa against oxidative injury induced by H. pylori or NSAIDs.

Sulforaphane Prevents Testicular Damage in Kunming Mice Exposed to Cadmium via Activation of Nrf2/ARE Signaling Pathways

Sulforaphane (SFN) is a natural and highly effective antioxidant. Studies suggest that SFN protects cells and tissues against cadmium (Cd) toxicity. This study investigated the protective effect of SFN against oxidative damage in the testes of Kunming mice exposed to cadmium, and explored the possible molecular mechanisms involved. Cadmium greatly reduced the serum testosterone levels in mice, reduced sperm motility, total sperm count, and increased the sperm deformity rate. Cadmium also reduces superoxide dismutase (T-SOD) and glutathione (GSH) levels and increases malondialdehyde (MDA) concentrations. SFN intervention improved sperm quality, serum testosterone, and antioxidant levels. Both mRNA and protein expression of mouse testicular nuclear factor-erythroid 2-related factor 2 (Nrf2) was reduced in cadmium-treated group. Furthermore, the downstream genes of Nrf2, glutathione peroxidase (GSH-Px), γ-glutamyl cysteine synthetase (γ-GCS), heme oxygenase-1 (HO-1), and NAD(P)H:quinone oxidoreductase-1 (NQO1) were also decreased in cadmium-treated group. SFN intervention increases the expression of these genes. Sulforaphane prevents cadmium-induced testicular damage, probably via activation of Nrf2/ARE signaling.

Bioavailability of Glucosinolates and Their Breakdown Products: Impact of Processing

Glucosinolates are a large group of plant secondary metabolites with nutritional effects, and are mainly found in cruciferous plants. After ingestion, glucosinolates could be partially absorbed in their intact form through the gastrointestinal mucosa. However, the largest fraction is metabolized in the gut lumen. When cruciferous are consumed without processing, myrosinase enzyme present in these plants hydrolyzes the glucosinolates in the proximal part of the gastrointestinal tract to various metabolites, such as isothiocyanates, nitriles, oxazolidine-2-thiones, and indole-3-carbinols. When cruciferous are cooked before consumption, myrosinase is inactivated and glucosinolates transit to the colon where they are hydrolyzed by the intestinal microbiota. Numerous factors, such as storage time, temperature, and atmosphere packaging, along with inactivation processes of myrosinase are influencing the bioavailability of glucosinolates and their breakdown products. This review paper summarizes the assimilation, absorption, and elimination of these molecules, as well as the impact of processing on their bioavailability.

Dietary amelioration of Helicobacter infection

We review herein the basis for using dietary components to treat and/or prevent Helicobacter pylori infection, with emphasis on (a) work reported in the last decade, (b) dietary components for which there is mechanism-based plausibility, and (c) components for which clinical results on H pylori amelioration are available. There is evidence that a diet-based treatment may reduce the levels and/or the virulence of H pylori colonization without completely eradicating the organism in treated individuals. This concept was endorsed a decade ago by the participants in a small international consensus conference held in Honolulu, Hawaii, USA, and interest in such a diet-based approach has increased dramatically since then. This approach is attractive in terms of cost, treatment, tolerability, and cultural acceptability. This review, therefore, highlights specific foods, food components, and food products, grouped as follows: bee products (eg, honey and propolis); probiotics; dairy products; vegetables; fruits; oils; essential oils; and herbs, spices, and other plants. A discussion of the small number of clinical studies that are available is supplemented by supportive in vitro and animal studies. This very large body of in vitro and preclinical evidence must now be followed up with rationally designed, unambiguous human trials.

A comparative study of broccoli sprouts powder and standard triple therapy on cardiovascular risk factors following H.pylori eradication: a randomized clinical trial in patients with type 2 diabetes

Background

In this clinical trial we compared the effects of broccoli sprouts powder, as an alternative and complementary treatment, to those of standard triple therapy, as a common medical treatment, on cardiovascular risk factors following the H.pylori eradication in patients with type 2 diabetes.

Methods

Eighty-six type 2 diabetic patients with positive H.pylori stool antigen test (HpSAg) were randomized to receive one of the three following regimens: STT) Standard triple therapy (omeprazole 20 mg, clarithromycin 500 mg, amoxicillin 1000 mg, twice a day for 14 days), BSP) 6 g/d broccoli sprouts powder for 28 days, and combination of these as STT + BSP. After 4 weeks of treatment, H.pylori eradication rates were assessed by HpSAg. Anthropometric measures, blood pressure, serum lipids and lipoproteins as well as serum high sensitive- C reactive protein were also assessed at baseline and at the second examination.

Results

Seventy-seven participants completed the study [STT (n = 28), BSP (n = 25), STT + BSP (n = 24)]. The H.pylori eradication rates were 89.3%, 56.0% and 91.7% in STT, BSP and STT + BSP groups, respectively. After the treatment, both systolic and diastolic blood pressure significantly decreased in STT + BSP group (P < 0.05). Serum triglycerides and TG/HDL-C ratio increased in STT patients group (<0.05). Serum hs-CRP levels significantly decreased in the patients who were treated with BSP per se (3.0 ± 2.5 at baseline vs. 2.3 ± 2.1 after the treatment, P < 0.05).

Conclusion

Compared to standard triple therapy, BSP regimen in addition to considerable effects on H.pylori eradication had also favorable properties on cardiovascular risk factors following the H.pylori eradication.

Exploring alternative treatments for Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a successful pathogen that can persist in the stomach of an infected person for their entire life. It provokes chronic gastric inflammation that leads to the development of serious gastric diseases such as peptic ulcers, gastric cancer and Mucosa associated lymphoid tissue lymphoma. It is known that these ailments can be avoided if the infection by the bacteria can be prevented or eradicated. Currently, numerous antibiotic-based therapies are available. However, these therapies have several inherent problems, including the appearance of resistance to the antibiotics used and associated adverse effects, the risk of re-infection and the high cost of antibiotic therapy. The delay in developing a vaccine to prevent or eradicate the infection has furthered research into new therapeutic approaches. This review summarises the most relevant recent studies on vaccine development and new treatments using natural resources such as plants, probiotics and nutraceuticals. In addition, novel alternatives based on microorganisms, peptides, polysaccharides, and intragastric violet light irradiation are presented. Alternative therapies have not been effective in eradicating the bacteria but have been shown to maintain low bacterial levels. Nevertheless, some of them are useful in preventing the adverse effects of antibiotics, modulating the immune response, gastroprotection, and the general promotion of health. Therefore, those agents can be used as adjuvants of allopathic anti-H. pylori eradication therapy.

Towards understanding the low prevalence of Helicobacter pylori in Malays: genetic variants among Helicobacter pylori-negative ethnic Malays in the north-eastern region of Peninsular Malaysia and Han Chinese and South Indians

OBJECTIVES

To identify gene polymorphisms that differ between Malays, Han Chinese and South Indians, and to identify candidate genes for the investigation of their role in protecting Malays from Helicobacter pylori (H. pylori) infection.

METHODS

Malay participants born and residing in Kelantan with a documented absence of H. pylori infection were studied. Venous blood was used for genotyping using the Affymetrix 50K Xba I kit. CEL files from 141 Han Chinese and 76 South Indians were analyzed to compare their allele frequency with that of the Malays using fixation index (FST ) calculation. The single nucleotide polymorphisms (SNPs) with the highest allele frequency (outliers) were then examined for their functional characteristics using F-SNP software and the Entrez Gene database.

RESULTS

In all, 37 Malays were enrolled in the study; of whom 7 were excluded for low genotyping call rates. The average FST estimated from the genome-wide data were 0.038 (Malays in Kelantan vs the South Indians), 0.015 (Malays in Kelantan vs Han Chinese) and 0.066 (Han Chinese vs South Indians), respectively. The outlier gene variants present in Malays with functional characteristics were C7orf10 (FST  0.29988), TSTD2 (FST  0.43278), SMG7 (FST  0.29877) and XPA (FST  0.43393 and 0.43644).

CONCLUSION

Genetic variants possibly related to protection against H. pylori infection in ethnic Malays from the north-eastern region of Peninsular Malaysia were identified for testing in subsequent trials among infected and uninfected Malays.

Sulforaphane regulates self-renewal of pancreatic cancer stem cells through the modulation of Sonic hedgehog-GLI pathway

Sulforaphane (SFN), a component of dietary cruciferous vegetables has been characterized for its anti-proliferative properties. We have recently demonstrated that pancreatic CSCs display activation of sonic hedgehog pathway which are fundamental drivers of stem cell renewal, and SFN inhibits the self-renewal of pancreatic CSCs in vitro. Consistent with these observations, we sought to determine the chemopreventive potential of SFN in an in vivo setting. We show here for the first time that sulforaphane treatment resulted in a significant reduction in the tumor growth of orthotopically implanted primary pancreatic CSCs isolated from human pancreatic tumors into the pancreas of NOD/SCID/IL2Rgamma mice, which is mediated through the modulation of Sonic hedgehog-GLI signaling. Hedgehog pathway blockade by SFN at a dose of 20 mg/kg resulted in a 45 % reduction in growth of pancreatic cancer tumors and reduced expression of Shh pathway components, Smo, Gli 1, and Gli 2 in mouse tissues. Further, SFN inhibited the expression of pluripotency maintaining transcription factors Nanog and Oct-4 and angiogenic markers VEGF and PDGFRα which are downstream targets of Gli transcription. Furthermore, SFN treatment resulted in a significant reduction in EMT markers Zeb-1, which correlated with increase in E-Cadherin expression suggesting the blockade of signaling involved in early metastasis. Interestingly, SFN downregulated the expression of Bcl-2 and XIAP to induce apoptosis. These data demonstrate that, at a tolerable dose, inhibition of Shh pathway by SFN results in marked reduction in EMT, metastatic, angiogenic markers with significant inhibition in tumor growth in mice. Since aberrant Shh signaling occurs in pancreatic tumorigenesis, therapeutics that target Shh pathway may improve the outcomes of patients with pancreatic cancer by targeting CSCs, thus suggesting the use of sulforaphane to further improve preventive and therapeutic approaches in patients with this devastating disease.

Enhanced in vitro biological activity of synthetic 2-(2-pyridyl) ethyl isothiocyanate compared to natural 4-(methylsulfinyl) butyl isothiocyanate

Dietary isothiocyanates (ITC) derived from cruciferous vegetables have been shown to have numerous biological effects consistent with chemoprotective activity. In this study we synthesized a novel ITC, 2-(2-pyridyl) ethyl ITC (PY-ITC), and assessed its chemopreventive ability in comparison to sulforaphane (SF), the ITC derived from broccoli. PY-ITC suppressed cancerous cell growth and proliferation at lower concentrations than SF and was more potent at inducing p21 protein. Through the use of whole genome arrays we demonstrate that prostate cells exposed to PY-ITC or SF have similar biological response, albeit PY-ITC alters a greater number of genes, and to a greater extent. In the presence of a phosphatidylinositol-3-kinase (PI3K) inhibitor PY-ITC had a more pronounced effect on gene expression, emphasizing the important role of PI3K/AKT signaling in mediating the chemopreventive effects of ITCs. These results highlight the importance of the ITC side chain in bioactivity.

Engineering glucosinolates in plants: current knowledge and potential uses

Glucosinolates (GSL) and their derivatives are well known for the characteristic roles they play in plant defense as signaling molecules and as bioactive compounds for human health. More than 130 GSLs have been reported so far, and most of them belong to the Brassicaceae family. Several enzymes and transcription factors involved in the GSL biosynthesis have been studied in the model plant, Arabidopsis, and in a few other Brassica crop species. Recent studies in GSL research have defined the regulation, distribution, and degradation of GSL biosynthetic pathways; however, the underlying mechanism behind transportation of GSLs in plants is still largely unknown. This review highlights the recent advances in the metabolic engineering of GSLs in plants and discusses their potential applications.

Organ-specific exposure and response to sulforaphane, a key chemopreventive ingredient in broccoli: implications for cancer prevention

Naturally occurring sulforaphane (SF) has been extensively studied for cancer prevention. However, little is known as to which organs may be most affected by this agent, which impedes its further development. In the present study, SF was administered to rats orally either in a single dose or once daily for 7 d. Tissue distribution of SF was measured by a HPLC-based method. Glutathione S-transferase (GST) and NAD(P)H:quinone oxidoreductase 1 (NQO1), two well-known cytoprotective phase 2 enzymes, were measured using biochemical assays to assess tissue response to SF. SF was delivered to different organs in vastly different concentrations. Tissue uptake of SF was the greatest in the stomach, declining rapidly in the descending gastro-intestinal tract. SF was rapidly eliminated through urinary excretion, and urinary concentrations of SF equivalents were 2-4 orders of magnitude higher than those of plasma. Indeed, tissue uptake level of SF in the bladder was second only to that in the stomach. Tissue levels of SF in the colon, prostate and several other organs were very low, compared to those in the bladder and stomach. Moreover, induction levels of GST and NQO1 varied by 3- to 6-fold among the organs of SF-treated rats, though not strictly correlated with tissue exposure to SF. Thus, there is profound organ specificity in tissue exposure and response to dietary SF, suggesting that the potential chemopreventive benefit of dietary SF may differ significantly among organs. These findings may provide a basis for prioritising organs for further chemopreventive study of SF.

Natural isothiocyanates: genotoxic potential versus chemoprevention

Isothiocyanates, occurring in many dietary cruciferous vegetables, show interesting chemopreventive activities against several chronic-degenerative diseases, including cancer, cardiovascular diseases, neurodegeneration, diabetes. The electrophilic carbon residue in the isothiocyanate moiety reacts with biological nucleophiles and modification of proteins is recognized as a key mechanism underlying the biological activity of isothiocyanates. The nuclear factor-erythroid-2-related factor 2 system, which orchestrates the expression of a wide array of antioxidant genes, plays a role in the protective effect of isothiocyanates against almost all the pathological conditions reported above. Recent emerging findings suggest a further common mechanism. Chronic inflammation plays a central role in many human diseases and isothiocyanates inhibit the activity of many inflammation components, suppress cyclooxygenase 2, and irreversibly inactivate the macrophage migration inhibitory factor. Due to their electrophilic reactivity, some isothiocyanates are able to form adducts with DNA and induce gene mutations and chromosomal aberrations. DNA damage has been demonstrated to be involved in the pathogenesis of various chronic-degenerative diseases of epidemiological relevance. Thus, the genotoxicity of the isothiocyanates should be carefully considered. In addition, the dose-response relationship for genotoxic compounds does not suggest evidence of a threshold. Thus, chemicals that are genotoxic pose a greater potential risk to humans than non-genotoxic compounds. Dietary consumption levels of isothiocyanates appear to be several orders of magnitude lower than the doses used in the genotoxicity studies and thus it is highly unlikely that such toxicities would occur in humans. However, the beneficial properties of isothiocyanates stimulated an increase of dietary supplements and functional foods with highly enriched isothiocyanate concentrations on the market. Whether such concentrations may exert a potential health risk cannot be excluded with certainty and an accurate evaluation of the toxicological profile of isothiocyanates should be prompted before any major increase in their consumption be recommended or their clinical use suggested.

Phytochemical analysis and antimicrobial activity of Cardaria draba (L.) Desv. volatiles

Two different volatile isolates from the aerial parts of Cardaria draba (L.) Desv., obtained either by hydrodistillation (Extract I) or by CH(2) Cl(2) extraction subsequent to hydrolysis by exogenous myrosinase (Extract II), were characterized by GC-FID and GC/MS analyses. The main volatiles obtained by hydrodistillation, i.e., 4-(methylsulfanyl)butyl isothiocyanate (1; 28.0%) and 5-(methylsulfanyl)pentanenitrile (2; 13.8%), originated from the degradation of glucoerucin. In Extract I, also volatiles without sulfur and/or nitrogen were identified. These were mostly hexadecanoic acid (10.8%), phytol (10.2%), dibutyl phthalate (4.5%), and some other compounds in smaller percentages. Extract II contained mostly glucosinolate degradation products. They originated from glucoraphanin, viz., 4-(methylsulfinyl)butyl isothiocyanate (3; 69.2%) and 5-(methylsulfinyl)pentanenitrile (4; 4.5%), glucosinalbin, viz., 2-(4-hydroxyphenyl)acetonitrile (5; 7.2%), and glucoerysolin, viz., 4-(methylsulfonyl)butyl isothiocyanate (6; 5.0%). Moreover, the volatile samples were evaluated for their antimicrobial activity using the disc-diffusion method and determining minimum inhibitory concentrations (MIC). All volatile isolates expressed a wide range of growth inhibition activity against both Gram-positive and Gram-negative bacteria and fungi. The MIC values varied between 4 and 128 μg/ml.

Analysis and anti-Helicobacter activity of sulforaphane and related compounds present in broccoli ( Brassica oleracea L.) sprouts

A crude methanol extract prepared from fresh broccoli sprouts was extracted with hexane, chloroform, ethyl acetate, and butanol sequentially. Residual water fraction was obtained from the residual aqueous layer. The greatest inhibition zones (>5 cm) were noted for Helicobacter pylori strain by the chloroform extract, followed by the hexane extract (5.03 cm), the ethyl acetate extract (4.90 cm), the butanol extract (3.10 cm), and the crude methanol extract (2.80 cm), whereas the residual water fraction did not show any inhibition zone. Including sulforaphane, five sulforaphane-related compounds were positively identified in the chloroform extract, of which 5-methylsulfinylpentylnitrile was found in the greatest concentration (475.7 mg/kg of fresh sprouts), followed by sulforaphane (222.6 mg/kg) and 4-methylsulfinylbutylnitrile (63.0 mg/kg). Among 18 sulforaphane and related compounds synthesized (6 amines, 6 isothiocyanates, and 6 nitriles), 2 amines, 6 isothiocyanates, and 1 nitrile exhibited >5 cm inhibitory zones for H. pylori strain. The results indicate that broccoli sprouts can be an excellent food source for medicinal substances.

Isothiocyanates, glutathione S-transferase M1 and T1 polymorphisms and gastric cancer risk: a prospective study of men in Shanghai, China

Isothiocyanates (ITC) in cruciferous vegetables may be chemopreventive against gastric cancer development. Glutathione S-transferases (GSTs) may modify the chemopreventive effect of ITC. The relationship between urinary total ITC and risk of gastric cancer was prospectively examined. Between 1986 and 1989, 18,244 middle-aged men in Shanghai, China were enrolled in a prospective study of diet and cancer and donated baseline urine and blood samples. Urinary ITC was quantified for 307 incident cases of gastric cancer that occurred during the first 16 years of follow-up, and 911 matched control subjects. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression methods. Seropositivity for antibodies to Helicobacter pylori and homozygous deletions of GSTM1 and GSTT1 were determined. Compared to the first tertile, ORs (95% CIs) of gastric cancer for the second and third tertiles of urinary total ITC were 0.83 (0.61-1.15) and 0.66 (0.47-0.94) (p(trend) = 0.02). A stronger protective effect of ITC against gastric cancer development was seen among men with homozygous deletion of GSTM1 (third tertile versus first tertile, OR = 0.50, 95% CI = 0.27-0.93) or GSTT1 (third tertile vs. first tertile, OR = 0.47, 95% CI = 0.25-0.88), and particularly with deletions of both GSTM1 and GSTT1 (second and third tertiles vs. first tertile, OR = 0.44, 95% CI = 0.21-0.93). In this cohort of Chinese men at high risk for gastric cancer, isothiocyanates may protect against the development of gastric cancer. The protection may be stronger for individuals genetically deficient in enzymes that metabolize these chemopreventive compounds.

The antimicrobial effects of glucosinolates and their respective enzymatic hydrolysis products on bacteria isolated from the human intestinal tract

AIMS

The aim of the study was to evaluate the in vitro antibacterial activity of glucosinolates and their enzymatic hydrolysis product against bacteria isolated from the human intestinal tract.

METHODS AND RESULTS

Using a disc diffusion bioassay, different doses of intact glucosinolates and their corresponding hydrolysis products were tested. There were clear structure-activity and concentration differences with respect to the in vitro growth inhibition effects as well as differences in the sensitivities of the individual bacteria. The most effective glucosinolate hydrolysis products were the isothiocyanates; sulforaphane and benzyl isothiocyanate were the best inhibitors of growth. Indole-3-carbinol had some inhibitory effects against the Gram-positive bacteria but had no effect, even at the highest dose, against the Gram-negative bacteria. Indole-3-acetonitrile had some inhibitory activity against the Gram-negative bacteria. Glucosinolates, nitriles and amines were ineffective at all the doses used.

CONCLUSIONS

Glucosinolate hydrolysis products and specifically the isothiocyanates SFN and BITC have significant antimicrobial activity against Gram-positive and Gram-negative bacteria, and might be useful in controlling human pathogens through the diet.

SIGNIFICANCE AND IMPACT OF THE STUDY

This the first major in vitro study demonstrating the potential of these natural dietary chemicals as an alternative to, or in combination with, current antibiotic-based therapies for treating infectious diseases.

The Nrf2/ARE pathway as a potential therapeutic target in neurodegenerative disease

Nuclear factor E2-related factor 2 (Nrf2) is a transcription factor known to induce expression of a variety of cytoprotective and detoxification genes. Several of the genes commonly regulated by Nrf2 have been implicated in protection from neurodegenerative conditions. Work from several laboratories has uncovered the potential for Nrf2-mediated transcription to protect from neurodegeneration resulting from mechanisms involving oxidative stress. For this reason, Nrf2 may be considered a therapeutic target for conditions that are known to involve free radical damage. Because common mechanisms of neurodegeneration, such as mitochondrial dysfunction and build-up of reactive oxygen species, are currently being uncovered, targeting Nrf2 may be valuable in combating conditions with variable causes and etiologies. Most effectively to target this protein in neurodegenerative conditions, a description of the involvement of Nrf2 and potential for neuroprotection must come from laboratory models. Herein, we review the current literature that suggests that Nrf2 may be a valuable therapeutic target for neurodegenerative disease, as well as experiments that illustrate potential mechanisms of protection.

Broccoli flower head extract reduces mitomycin-C induced sister chromatid exchange in cultured human lymphocytes

This study is a continuation of our previous work [Murugan, S.S., Balakrishnamurthy, P., Mathew, Y.J., 2007. Antimutagenic effect of broccoli flower head by the Ames Salmonella reverse mutation assay. Phytother. Res. 21, 545-547], in search of possible antimutagenic properties in broccoli flower head extracts. In the present investigation, the effect of addition of ethanol extract of broccoli flower head on mitomycin-C (MMC) induced sister chromatid exchange (SCE) in cultured human peripheral blood lymphocytes was investigated. Broccoli flower head was extracted in ethanol using either acetone or ethanol as solvents. The extract was tested at final concentrations of 200 and 400 microg/ml culture and set for SCE assay. MMC at a concentration of 1 microg/ml and the test concentrations of broccoli flower head were added to the culture following 48 h from the initiation of culture. Enumeration of SCE in second division mitotic cells indicated that broccoli flower head extract significantly reduced MMC induced SCEs at both the concentrations tested. This observation is in line with our earlier finding and confirms to the presence of antimutagenic principles in broccoli flower head extract.

Discovery and development of sulforaphane as a cancer chemopreventive phytochemical

Sulforaphane (SF) is a phytochemical that displays both anticarcinogenic and anticancer activity. SF modulates many cancer-related events, including susceptibility to carcinogens, cell death, cell cycle, angiogenesis, invasion and metastasis. We review its discovery and development as a cancer chemopreventive agent with the intention of encouraging further research on this important compound and facilitating the identification and development of new phytochemicals for cancer prevention.

Isothiocyanate Inhibits Restitution and Wound Repair after Injury in the Stomach: Ex Vivo and in Vitro Studies

The role of isothiocyanate (ITC) in blocking epithelial restitution after injury and in the recovery of round wounds was examined in the ex vivo guinea pig stomach and in rat gastric mucosal-1 (RGM1) cells, respectively. For this, recovery of transepithelial electrical resistance and morphology after injury or the closure of round wounds was evaluated in the presence of 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) or 4,4-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid (H2DIDS) (two ITC groups), 4-acetamido-4-isothiocyanatostilbene-2,2'-disulfonic acid (SITS) (one ITC group), or 4,4-diinitrostilbene-2,2'-disulfonic acid (DNDS) (no ITC groups). Wounded RGM1 cells were also incubated with bicarbonate-free buffer, ATP, barium, or phloretin to determine the mechanism of ITC inhibition. At 300 microM, DIDS or H2DIDS blocked restitution and wound repair by 100%, SITS blocked wound repair by 50%, and DNDS blocked wound repair by 2%. These results demonstrate the dependence of restitution and wound repair on ITC. ITC-binding purino (ATP) receptors and KATP channels were investigated as potential sites of inhibition, but they were found not to be the target of ITC in wound repair. Phloretin, blocking the monocarboxylate transporter (MCT), dose-dependently inhibited wound repair, and this result was exacerbated when the sodium bicarbonate cotransporter (NBC) was also blocked by bicarbonate-free conditions, resulting in 100% inhibition of wound repair with no reduction in viability when both transporters were blocked simultaneously. ITC potently inhibits both MCT and NBC, which may account for the inhibitory action of DIDS during restitution and wound repair. Reverse transcription-polymerase chain reaction data verified that MCT-1 is expressed in RGM1 cells. In conclusion, our results suggest that bicarbonate and monocarboxylate transport may work cooperatively to facilitate restitution of the gastric mucosa after injury.

Cruciferous vegetables and human cancer risk: epidemiologic evidence and mechanistic basis

Cruciferous vegetables are a rich source of glucosinolates and their hydrolysis products, including indoles and isothiocyanates, and high intake of cruciferous vegetables has been associated with lower risk of lung and colorectal cancer in some epidemiological studies. Glucosinolate hydrolysis products alter the metabolism or activity of sex hormones in ways that could inhibit the development of hormone-sensitive cancers, but evidence of an inverse association between cruciferous vegetable intake and breast or prostate cancer in humans is limited and inconsistent. Organizations such as the National Cancer Institute recommend the consumption of five to nine servings of fruits and vegetables daily, but separate recommendations for cruciferous vegetables have not been established. Isothiocyanates and indoles derived from the hydrolysis of glucosinolates, such as sulforaphane and indole-3-carbinol (I3C), have been implicated in a variety of anticarcinogenic mechanisms, but deleterious effects also have been reported in some experimental protocols, including tumor promotion over prolonged periods of exposure. Epidemiological studies indicate that human exposure to isothiocyanates and indoles through cruciferous vegetable consumption may decrease cancer risk, but the protective effects may be influenced by individual genetic variation (polymorphisms) in the metabolism and elimination of isothiocyanates from the body. Cooking procedures also affect the bioavailability and intake of glucosinolates and their derivatives. Supplementation with I3C or the related dimer 3,3'-diindolylmethane (DIM) alters urinary estrogen metabolite profiles in women, but the effects of I3C and DIM on breast cancer risk are not known. Small preliminary trials in humans suggest that I3C supplementation may be beneficial in treating conditions related to human papilloma virus infection, such as cervical intraepithelial neoplasia and recurrent respiratory papillomatosis, but larger randomized controlled trials are needed.