Sulforaphane enriched transcriptome of lung mitochondrial energy metabolism and provided pulmonary injury protection via Nrf2 in mice.

Nrf2 is essential to antioxidant response element (ARE)-mediated host defense. Sulforaphane (SFN) is a phytochemical antioxidant known to affect multiple cellular targets including Nrf2-ARE pathway in chemoprevention. However, the role of SFN in non-malignant airway disorders remain unclear. To test if pre-activation of Nrf2-ARE signaling protects lungs from oxidant-induced acute injury, wild-type (Nrf2+/+) and Nrf2-deficient (Nrf2-/-) mice were given SFN orally or as standardized broccoli sprout extract diet (SBE) before hyperoxia or air exposure. Hyperoxia-induced pulmonary injury and oxidation indices were significantly reduced by SFN or SBE in Nrf2+/+ mice but not in Nrf2-/- mice. SFN upregulated a large cluster of basal lung genes that are involved in mitochondrial oxidative phosphorylation, energy metabolism, and cardiovascular protection only in Nrf2+/+ mice. Bioinformatic analysis elucidated ARE-like motifs on these genes. Transcript abundance of the mitochondrial machinery genes remained significantly higher after hyperoxia exposure in SFN-treated Nrf2+/+ mice than in SFN-treated Nrf2-/- mice. Nuclear factor-κB was suggested to be a central molecule in transcriptome networks affected by SFN. Minor improvement of hyperoxia-caused lung histopathology and neutrophilia by SFN in Nrf2-/- mice implies Nrf2-independent or alternate effector mechanisms. In conclusion, SFN is suggested to be as a preventive intervention in a preclinical model of acute lung injury by linking mitochondria and Nrf2. Administration of SFN alleviated acute lung injury-like pathogenesis in a Nrf2-dependent manner. Potential AREs in the SFN-inducible transcriptome for mitochondria bioenergetics provided a new insight into the downstream mechanisms of Nrf2-mediated pulmonary protection.

Sulforaphane from Broccoli Reduces Symptoms of Autism: A Follow-up Case Series from a Randomized Double-blind Study.

INTRODUCTION: Autism spectrum disorder (ASD) affects 1 in 68 children, is characterized by impaired social interaction and communication as well as restricted or repetitive behaviors, and varies widely with respect to its causes and presentations. There are no validated pharmacologic treatments for the core symptoms of ASD. The social, medical, and economic burdens of ASD on families and caregivers are profound. We recently showed in a small clinical trial that sulforaphane (SF) from broccoli sprouts could significantly reduce the behavioral symptoms of ASD. METHODS: After we completed the intervention phase of the original trial (2011-2013), many caregivers used over-the-counter dietary SF supplements in order to attempt to maintain improvements similar to those noted during the intervention. We periodically followed the progress of study participants through the summer of 2016. RESULTS: Families of 16 of the 26 subjects who received SF as part of the original study responded to requests for further information. Of these subjects, 6 did not continue taking SF supplements after the study. Nine of the 16 subjects are still taking an SF supplement and a 10th planned to. We present the edited testimonials of their caregivers in this case series. CONCLUSIONS: Many parents and caregivers articulated the positive effects of SF, both during the intervention phase and in the ensuing 3 years reported herein. These observations may contribute to understanding ASD and to treatments that may alleviate some of its symptoms. Diet- and supplement-based therapies deserve careful consideration for their potential to provide vital clinical as well as biochemical information about ASD.

Transcription factors NRF2 and HSF1 have opposing functions in autophagy.

Autophagy plays a critical role in the maintenance of cellular homeostasis by degrading proteins, lipids and organelles. Autophagy is activated in response to stress, but its regulation in the context of other stress response pathways, such as those mediated by heat shock factor 1 (HSF1) and nuclear factor-erythroid 2 p45-related factor 2 (NRF2), is not well understood. We found that the Michael acceptor bis(2-hydoxybenzylidene)acetone (HBB2), a dual activator of NRF2 and HSF1, protects against the development of UV irradiation-mediated cutaneous squamous cell carcinoma in mice. We further show that HBB2 is an inducer of autophagy. In cells, HBB2 increases the levels of the autophagy-cargo protein p62/sequestosome 1, and the lipidated form of microtubule-associated protein light chain 3 isoform B. Activation of autophagy by HBB2 is impaired in NRF2-deficient cells, which have reduced autophagic flux and low basal and induced levels of p62. Conversely, HSF1-deficient cells have increased autophagic flux under both basal as well as HBB2-induced conditions, accompanied by increased p62 levels. Our findings suggest that NRF2 and HSF1 have opposing roles during autophagy, and illustrate the existence of tight mechanistic links between the cellular stress responses.

Correction: Lack of Effect of Oral Sulforaphane Administration on Nrf2 Expression in COPD: A Randomized, Double-Blind, Placebo Controlled Trial.

[This corrects the article DOI: 10.1371/journal.pone.0163716.].

Stabilized sulforaphane for clinical use: Phytochemical delivery efficiency.

SCOPE: The isothiocyanate sulforaphane (SF) from broccoli is one of the most potent known inducers of the cytoprotective phase 2 response. Its role in a host of biochemical pathways makes it a major component of plant-based protective strategies for enhancing healthspan. Many nutritional supplements are now marketed that purport to contain SF, which in plants exists as a stable precursor, a thioglucoside hydroxysulfate. However, SF in pure form must be stabilized for use in supplements. METHODS AND RESULTS: We evaluated the stability and bioavailability of two stabilized SF preparations-an α-cyclodextrin inclusion (SF-αCD), and an SF-rich, commercial nutritional supplement. SF-αCD area-under-the-curve peak serum concentrations occurred at 2 h, but six of ten volunteers complained of mild stomach upset. After topical application it was not effective in upregulating cytoprotective enzymes in the skin of SKH1 mice whereas pure SF was effective in doing so. Both of these "stabilized" SF preparations were as potent as pure SF in inducing the cytoprotective response in cultured cells, and they were more stable and as bioavailable. CONCLUSION: Our studies of a stabilized phytochemical component of foods should encourage further examination of similar products for their utility in chronic disease prevention and therapy.

Lack of Effect of Oral Sulforaphane Administration on Nrf2 Expression in COPD: A Randomized, Double-Blind, Placebo Controlled Trial.

BACKGROUND: COPD patients have high pulmonary and systemic oxidative stress that correlates with severity of disease. Sulforaphane has been shown to induce expression of antioxidant genes via activation of a transcription factor, nuclear factor erythroid-2 related factor 2 (Nrf2). METHODS: This parallel, placebo-controlled, phase 2, randomized trial was conducted at three US academic medical centers. Patients who met GOLD criteria for COPD and were able to tolerate bronchoscopies were randomly assigned (1:1:1) to receive placebo, 25 µmoles, or 150 µmoles sulforaphane daily by mouth for four weeks. The primary outcomes were changes in Nrf2 target gene expression (NQ01, HO1, AKR1C1 and AKR1C3) in alveolar macrophages and bronchial epithelial cells. Secondary outcomes included measures of oxidative stress and airway inflammation, and pulmonary function tests. RESULTS: Between July 2011 and May 2013, 89 patients were enrolled and randomized. Sulforaphane was absorbed in the patients as evident from their plasma metabolite levels. Changes in Nrf2 target gene expression relative to baseline ranged from 0.79 to 1.45 and there was no consistent pattern among the three groups; the changes were not statistically significantly different from baseline. Changes in measures of inflammation and pulmonary function tests were not different among the groups. Sulforaphane was well tolerated at both dose levels. CONCLUSION: Sulforaphane administered for four weeks at doses of 25 µmoles and 150 µmoles to patients with COPD did not stimulate the expression of Nrf2 target genes or have an effect on levels of other anti-oxidants or markers of inflammation. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01335971.

Biomarker-Guided Strategy for Treatment of Autism Spectrum Disorder (ASD).

Autism spectrum disorder (ASD) is a complex, life-long neurodevelopmental disorder currently affecting an estimated 1 out of 68 among children aged 8 y in the United States. ASD has complex genetic and epigenetic features that lead to the phenotype and there is no single genetic marker for the diagnosis. Therefore, the diagnosis for ASD is phenotype- based with no validated or credible laboratory tests available. Evidence-based treatments for ASD are limited. There is no FDA approved medical therapy that addresses either core ASD symptoms or pathophysiological processes associated with ASD. We outline herein, several ASD-associated basic physiological pathways that can be regulated by the small molecule phytochemical sulforaphane, as an example of a druggable small molecule target for which much in vitro, pre-clinical, and clinical evidence already exists: (1) redox metabolism/oxidative stress, (2) mitochondrial dysfunction, (3) immune dysregulation/neuroinflammation, (4) febrile illness and the heat shock response, and (5) synaptic dysfunction. Furthermore, we identify the biomarkers that can be used to assess the functioning of these pathways as well as suggesting how these biomarkers could guide novel treatment strategies to correct these biochemical abnormalities in order to improve core and associated symptoms of ASD.

Sulforaphane Bioavailability from Glucoraphanin-Rich Broccoli: Control by Active Endogenous Myrosinase.

Glucoraphanin from broccoli and its sprouts and seeds is a water soluble and relatively inert precursor of sulforaphane, the reactive isothiocyanate that potently inhibits neoplastic cellular processes and prevents a number of disease states. Sulforaphane is difficult to deliver in an enriched and stable form for purposes of direct human consumption. We have focused upon evaluating the bioavailability of sulforaphane, either by direct administration of glucoraphanin (a glucosinolate, or ß-thioglucoside-N-hydroxysulfate), or by co-administering glucoraphanin and the enzyme myrosinase to catalyze its conversion to sulforaphane at economic, reproducible and sustainable yields. We show that following administration of glucoraphanin in a commercially prepared dietary supplement to a small number of human volunteers, the volunteers had equivalent output of sulforaphane metabolites in their urine to that which they produced when given an equimolar dose of glucoraphanin in a simple boiled and lyophilized extract of broccoli sprouts. Furthermore, when either broccoli sprouts or seeds are administered directly to subjects without prior extraction and consequent inactivation of endogenous myrosinase, regardless of the delivery matrix or dose, the sulforaphane in those preparations is 3- to 4-fold more bioavailable than sulforaphane from glucoraphanin delivered without active plant myrosinase. These data expand upon earlier reports of inter- and intra-individual variability, when glucoraphanin was delivered in either teas, juices, or gelatin capsules, and they confirm that a variety of delivery matrices may be equally suitable for glucoraphanin supplementation (e.g. fruit juices, water, or various types of capsules and tablets).

Sulforaphane improves the bronchoprotective response in asthmatics through Nrf2-mediated gene pathways.

BACKGROUND: It is widely recognized that deep inspiration (DI), either before methacholine (MCh) challenge (Bronchoprotection, BP) or after MCh challenge (Bronchodilation, BD) protects against this challenge in healthy individuals, but not in asthmatics. Sulforaphane, a dietary antioxidant and antiinflammatory phytochemical derived from broccoli, may affect the pulmonary bronchoconstrictor responses to MCh and the responses to DI in asthmatic patients. METHODS: Forty-five moderate asthmatics were administered sulforaphane (100 µmol daily for 14 days), BP, BD, lung volumes by body-plethsmography, and airway morphology by computed tomography (CT) were measured pre- and post sulforaphane consumption. RESULTS: Sulforaphane ameliorated the bronchoconstrictor effects of MCh on FEV1 significantly (on average by 21 %; p = 0.01) in 60 % of these asthmatics. Interestingly, in 20 % of the asthmatics, sulforaphane aggravated the bronchoconstrictor effects of MCh and in a similar number was without effect, documenting the great heterogeneity of the responsiveness of these individuals to sulforaphane. Moreover, in individuals in whom the FEV1 response to MCh challenge decreased after sulforaphane administration, i.e., sulforaphane was protective, the activities of Nrf2-regulated antioxidant and anti-inflammatory genes decreased. In contrast, individuals in whom sulforaphane treatment enhanced the FEV1 response to MCh, had increased expression of the activities of these genes. High resolution CT scans disclosed that in asthmatics sulforaphane treatment resulted in a significant reduction in specific airway resistance and also increased small airway luminal area and airway trapping modestly but significantly. CONCLUSION: These findings suggest the potential value of blocking the bronchoconstrictor hyperresponsiveness in some types of asthmatics by phytochemicals such as sulforaphane.

Nrf2 Activation Protects against Solar-Simulated Ultraviolet Radiation in Mice and Humans.

The transcription factor Nrf2 determines the ability to adapt and survive under conditions of electrophilic, oxidative, and inflammatory stress by regulating the expression of elaborate networks comprising nearly 500 genes encoding proteins with versatile cytoprotective functions. In mice, disruption of Nrf2 increases susceptibility to carcinogens and accelerates disease pathogenesis. Paradoxically, Nrf2 is upregulated in established human tumors, but whether this upregulation drives carcinogenesis is not known. Here we show that the incidence, multiplicity, and burden of solar-simulated UV radiation-mediated cutaneous tumors that form in SKH-1 hairless mice in which Nrf2 is genetically constitutively activated are lower than those that arise in their wild-type counterparts. Pharmacologic Nrf2 activation by topical biweekly applications of small (40 nmol) quantities of the potent bis(cyano enone) inducer TBE-31 has a similar protective effect against solar-simulated UV radiation in animals receiving long-term treatment with the immunosuppressive agent azathioprine. Genetic or pharmacologic Nrf2 activation lowers the expression of the pro-inflammatory factors IL6 and IL1ß, and COX2 after acute exposure of mice to UV radiation. In healthy human subjects, topical applications of extracts delivering the Nrf2 activator sulforaphane reduced the degree of solar-simulated UV radiation-induced skin erythema, a quantifiable surrogate endpoint for cutaneous damage and skin cancer risk. Collectively, these data show that Nrf2 is not a driver for tumorigenesis even upon exposure to a very potent and complete carcinogen and strongly suggest that the frequent activation of Nrf2 in established human tumors is a marker of metabolic adaptation.

Sulforaphane treatment of autism spectrum disorder (ASD).

Autism spectrum disorder (ASD), characterized by both impaired communication and social interaction, and by stereotypic behavior, affects about 1 in 68, predominantly males. The medico-economic burdens of ASD are enormous, and no recognized treatment targets the core features of ASD. In a placebo-controlled, double-blind, randomized trial, young men (aged 13-27) with moderate to severe ASD received the phytochemical sulforaphane (n = 29)--derived from broccoli sprout extracts--or indistinguishable placebo (n = 15). The effects on behavior of daily oral doses of sulforaphane (50-150 µmol) for 18 wk, followed by 4 wk without treatment, were quantified by three widely accepted behavioral measures completed by parents/caregivers and physicians: the Aberrant Behavior Checklist (ABC), Social Responsiveness Scale (SRS), and Clinical Global Impression Improvement Scale (CGI-I). Initial scores for ABC and SRS were closely matched for participants assigned to placebo and sulforaphane. After 18 wk, participants receiving placebo experienced minimal change (<3.3%), whereas those receiving sulforaphane showed substantial declines (improvement of behavior): 34% for ABC (P < 0.001, comparing treatments) and 17% for SRS scores (P = 0.017). On CGI-I, a significantly greater number of participants receiving sulforaphane had improvement in social interaction, abnormal behavior, and verbal communication (P = 0.015-0.007). Upon discontinuation of sulforaphane, total scores on all scales rose toward pretreatment levels. Dietary sulforaphane, of recognized low toxicity, was selected for its capacity to reverse abnormalities that have been associated with ASD, including oxidative stress and lower antioxidant capacity, depressed glutathione synthesis, reduced mitochondrial function and oxidative phosphorylation, increased lipid peroxidation, and neuroinflammmation.

Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in China.

Broccoli sprouts are a convenient and rich source of the glucosinolate, glucoraphanin, which can generate the chemopreventive agent, sulforaphane, an inducer of glutathione S-transferases (GST) and other cytoprotective enzymes. A broccoli sprout-derived beverage providing daily doses of 600 µmol glucoraphanin and 40 µmol sulforaphane was evaluated for magnitude and duration of pharmacodynamic action in a 12-week randomized clinical trial. Two hundred and ninety-one study participants were recruited from the rural He-He Township, Qidong, in the Yangtze River delta region of China, an area characterized by exposures to substantial levels of airborne pollutants. Exposure to air pollution has been associated with lung cancer and cardiopulmonary diseases. Urinary excretion of the mercapturic acids of the pollutants, benzene, acrolein, and crotonaldehyde, were measured before and during the intervention using liquid chromatography tandem mass spectrometry. Rapid and sustained, statistically significant (P ≤ 0.01) increases in the levels of excretion of the glutathione-derived conjugates of benzene (61%), acrolein (23%), but not crotonaldehyde, were found in those receiving broccoli sprout beverage compared with placebo. Excretion of the benzene-derived mercapturic acid was higher in participants who were GSTT1-positive than in the null genotype, irrespective of study arm assignment. Measures of sulforaphane metabolites in urine indicated that bioavailability did not decline over the 12-week daily dosing period. Thus, intervention with broccoli sprouts enhances the detoxication of some airborne pollutants and may provide a frugal means to attenuate their associated long-term health risks.

Relevance of anti-inflammatory and antioxidant activities of exemestane and synergism with sulforaphane for disease prevention.

Exemestane (6-methyleneandrosta-1,4-diene-3,17-dione) is a synthetic steroidal inhibitor of the aromatase reaction that catalyzes the terminal and rate-limiting step of the biosynthesis of estrogens. It is active clinically in preventing, delaying progression of, and treating mammary cancers, many of which are estrogen receptor-positive. A striking feature of the structure of exemestane is an extended system of conjugated Michael reaction functions, which is also characteristic of inducers of a broad network of chemoprotective genes regulated by the Keap1 (Kelch-like ECA-associated protein)/Nrf2 (nuclear factor E2-related factor 2)/ARE (antioxidant response element) signaling system. These genes are largely involved in xenobiotic metabolism and antioxidative and anti-inflammatory protection, as well as the synthesis and reduction of glutathione. We show here that exemestane transcriptionally activates NAD(P)H:quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO-1), typical chemoprotective gene products, in a wide variety of mouse, rat, and human cells. It protects several cell lines against oxidative toxicity of tert-butyl hydroperoxide and 4-hydroxynonenal, against free radical damage arising from hypoxia-reoxygenation, and against UVA radiation damage. Exemestane also inhibits the inflammatory increases in inducible nitric oxide synthase (iNOS) in mouse macrophages exposed to LPS (lipopolysaccharide), thereby resembling the isothiocyanate sulforaphane derived from broccoli. Remarkably, combinations of exemestane and sulforaphane act highly synergistically, and this property is also displayed by several other phytochemicals. Thus, exemestane has a wide range of previously unrecognized protective activities, probably unrelated to aromatase inhibition. Its potential for reducing the risk, not only of breast cancer, but also of other chronic diseases that arise from inflammation, oxidative stress, and DNA-damaging electrophiles, requires exploration, particularly in view of the synergism with other phytochemicals.

Sulforaphane accelerates acetaldehyde metabolism by inducing aldehyde dehydrogenases: relevance to ethanol intolerance.

AIMS: Many East Asians are highly intolerant to even modest alcohol consumption. These individuals accumulate acetaldehyde, the primary metabolite of ethanol, because of a genetic polymorphism of aldehyde dehydrogenase (ALDH) that metabolizes acetaldehyde to nontoxic acetate. The aim of these studies is to upregulate ALDH by dietary means, thereby reducing acetaldehyde toxicity. METHODS: Sulforaphane [SF, 1-isothiocyano-4-(methylsulfinyl)butane] derived from its glucosinolate precursor contained in cruciferous vegetables and related inducers of the Keap1/Nrf2/ARE pathway were assessed for their potencies to induce ALDH in murine hepatoma Hepa1c1c7 cells. Inducer potencies for ALDH were compared with those for NQO1, a prototypical cytoprotective enzyme present downstream of the Keap1/Nrf2/ARE pathway. SF (5 or 20 µmol/day) was fed to CD-1 mice for 7 days prior to a single administration of ethanol, and then ALDH induction in organs and pharmacokinetics of acetaldehyde was examined. RESULTS: In addition to SF, other electrophiles, including many Michael reaction acceptors, induce ALDH. Potencies of these agents as inducers parallel their activities in inducing NQO1, and are also dependent on Nrf2. In mice, in vivo, feeding of SF induced tissue ALDH and dramatically increased (doubled) the rate of elimination of acetaldehyde arising from the administration of ethanol. CONCLUSION: SF and other edible phytochemicals may ameliorate the alcohol intolerance of individuals who are polymorphic with respect to ALDH.

Urease from Helicobacter pylori is inactivated by sulforaphane and other isothiocyanates.

Infections by Helicobacter pylori are very common, causing gastroduodenal inflammation including peptic ulcers, and increasing the risk of gastric neoplasia. The isothiocyanate (ITC) sulforaphane [SF; 1-isothiocyanato-4-(methylsulfinyl)butane] derived from edible crucifers such as broccoli is potently bactericidal against Helicobacter, including antibiotic-resistant strains, suggesting a possible dietary therapy. Gastric H. pylori infections express high urease activity which generates ammonia, neutralizes gastric acidity, and promotes inflammation. The finding that SF inhibits (inactivates) urease (jack bean and Helicobacter) raised the issue of whether these properties might be functionally related. The rates of inactivation of urease activity depend on enzyme and SF concentrations and show first order kinetics. Treatment with SF results in time-dependent increases in the ultraviolet absorption of partially purified Helicobacter urease in the 260-320 nm region. This provides direct spectroscopic evidence for the formation of dithiocarbamates between the ITC group of SF and cysteine thiols of urease. The potencies of inactivation of Helicobacter urease by isothiocyanates structurally related to SF were surprisingly variable. Natural isothiocyanates closely related to SF, previously shown to be bactericidal (berteroin, hirsutin, phenethyl isothiocyanate, alyssin, and erucin), did not inactivate urease activity. Furthermore, SF is bactericidal against both urease positive and negative H. pylori strains. In contrast, some isothiocyanates such as benzoyl-ITC, are very potent urease inactivators, but are not bactericidal. The bactericidal effects of SF and other ITC against Helicobacter are therefore not obligatorily linked to urease inactivation, but may reduce the inflammatory component of Helicobacter infections.

Keap1-nrf2 signaling: a target for cancer prevention by sulforaphane.

Sulforaphane is a promising agent under preclinical evaluation in many models of disease prevention. This bioactive phytochemical affects many molecular targets in cellular and animal models; however, amongst the most sensitive is Keap1, a key sensor for the adaptive stress response system regulated through the transcription factor Nrf2. Keap1 is a sulfhydryl-rich protein that represses Nrf2 signaling by facilitating the polyubiquitination of Nrf2, thereby enabling its subsequent proteasomal degradation. Interaction of sulforaphane with Keap1 disrupts this function and allows for nuclear accumulation of Nrf2 and activation of its transcriptional program. Enhanced transcription of Nrf2 target genes provokes a strong cytoprotective response that enhances resistance to carcinogenesis and other diseases mediated by exposures to electrophiles and oxidants. Clinical evaluation of sulforaphane has been largely conducted by utilizing preparations of broccoli or broccoli sprouts rich in either sulforaphane or its precursor form in plants, a stable ß-thioglucose conjugate termed glucoraphanin. We have conducted a series of clinical trials in Qidong, China, a region where exposures to food- and air-borne carcinogens has been considerable, to evaluate the suitability of broccoli sprout beverages, rich in either glucoraphanin or sulforaphane or both, for their bioavailability, tolerability, and pharmacodynamic action in population-based interventions. Results from these clinical trials indicate that interventions with well characterized preparations of broccoli sprouts may enhance the detoxication of aflatoxins and air-borne toxins, which may in turn attenuate their associated health risks, including cancer, in exposed individuals.

Neuroprotective effects of sulforaphane after contusive spinal cord injury.

Traumatic spinal cord injury (SCI) leads to oxidative stress, calcium mobilization, glutamate toxicity, the release of proinflammatory factors, and depletion of reduced glutathione (GSH) at the site of injury. Induction of the Keap1/Nrf2/ARE pathway can alleviate neurotoxicity by protecting against GSH depletion, oxidation, intracellular calcium overload, mitochondrial dysfunction, and excitotoxicity. Sulforaphane (SF), an isothiocyanate derived from broccoli, is a potent naturally-occurring inducer of the Keap1/Nrf2/ARE pathway, leading to upregulation of genes encoding cytoprotective proteins such as NAD(P)H: quinone oxidoreductase 1, and GSH-regulatory enzymes. Additionally, SF can attenuate inflammation by inhibiting the nuclear factor-κB (NF-κB) pathway, and the enzymatic activity of the proinflammatory cytokine macrophage inhibitory factor (MIF). Our study examined systemic administration of SF in a rat model of contusion SCI, in an effort to utilize its indirect antioxidant and anti-inflammatory properties to decrease secondary injury. Two doses of SF (10 or 50 mg/kg) were administered at 10 min and 72 h after contusion SCI. SF (50 mg/kg) treatment resulted in both acute and long-term beneficial effects, including upregulation of the phase 2 antioxidant response at the injury site, decreased mRNA levels of inflammatory cytokines (i.e., MMP-9) in the injured spinal cord, inactivation of urinary MIF tautomerase activity, enhanced hindlimb locomotor function, and an increased number of serotonergic axons caudal to the lesion site. These findings demonstrate that SF provides neuroprotective effects in the spinal cord after injury, and could be a candidate for therapy of SCI.

Notes from the field: "green" chemoprevention as frugal medicine.

Prevention trials of whole foods or simple extracts offer prospects for reducing an expanding global burden of cancer effectively, and in contrast to promising isolated phytochemicals or pharmaceuticals, frugally. We use the term "green" chemoprevention to differentiate a food-centered approach that is sustainable in underserved populations. It can be applied to personalized medicine just as well as a pharmaceutical approach, but only green chemoprevention can be applied in both rich and poor settings. This MiniReview discusses some of the challenges of conducting food-based trials in developing countries, with particular emphasis on moving the limited number of promising phase II trials forward as placebo-controlled randomized trials, the gold standard for prevention studies. How does one define a placebo for a food? What is the regulatory context of such a food-based product? How can such products be produced and standardized to the benefit of a larger, individual trial, and importantly, the research community at large? What are the challenges and opportunities of conducting such trials in the international setting? Finally, how does one make the science practical?

Protection of humans by plant glucosinolates: efficiency of conversion of glucosinolates to isothiocyanates by the gastrointestinal microflora.

Plant-based diets rich in crucifers are effective in preventing cancer and other chronic diseases. Crucifers contain very high concentrations of glucosinolates (GS; ß-thioglucoside-N-hydroxysulfates). Although not themselves protective, GS are converted by coexisting myrosinases to bitter isothiocyanates (ITC) which defend plants against predators. Coincidentally, ITC also induce mammalian genes that regulate defenses against oxidative stress, inflammation, and DNA-damaging electrophiles. Consequently, the efficiency of conversion of GS to ITC may be critical in controlling the health-promoting benefits of crucifers. If myrosinase is heat-inactivated by cooking, the gastrointestinal microflora converts GS to ITC, a process abolished by enteric antibiotics and bowel cleansing. When single oral doses of GS were administered as broccoli sprout extracts (BSE) to two dissimilar populations (rural Han Chinese and racially mixed Baltimoreans) patterns of excretions of urinary dithiocarbamates (DTC) were very similar. Individual conversions in both populations varied enormously, from about 1% to more than 40% of dose. In contrast, administration of ITC (largely sulforaphane)-containing BSE resulted in uniformly high (70%-90%) conversions to urinary DTC. Despite the remarkably large range of conversion efficiencies between individuals, repeated determinations within individuals were much more consistent. The rates of urinary excretion (slow or fast) were unrelated to the ultimate magnitudes (low or high) of these conversions. Although no demographic factors affecting conversion efficiency have been identified, there are clearly diurnal variations: conversion of GS to DTC was greater during the day, but conversion of ITC to DTC was more efficient at night.