Exploring the bioaccessibility of polyphenols and glucosinolates from Brassicaceae microgreens by combining metabolomics profiling and computational chemometrics

Microgreens constitute natural-based foods with health-promoting properties mediated by the accumulation of glucosinolates (GLs) and phenolic compounds (PCs), although their bioaccessibility may limit their nutritional potential. This work subjected eight Brassicaceae microgreens to in vitro gastrointestinal digestion and large intestine fermentation before the metabolomics profiling of PCs and GLs. The application of multivariate statistics effectively discriminated among species and their interaction with in vitro digestion phases. The flavonoids associated with arugula and the aliphatic GLs related to red cabbage and cauliflower were identified as discriminant markers among microgreen species. The multi-omics integration along in vitro digestion and fermentation predicted bioaccessible markers, featuring potential candidates that may eventually be responsible for these functional foods' nutritional properties. This combined analytical and computational framework provided a promising platform to predict the nutritional metabolome-wide outcome of functional food consumption, as in the case of microgreens.

Raw material-dependent changes in bacterial and compositional profiles are involved in insufficient pH decrease in natural lactic fermentation of Brassica rapa leaves

Sunki is an unsalted lactic fermented pickle made from red turnip leaves in the Kiso district, Japan. Accidental insufficient decrease in pH during sunki fermentation seriously reduces the product quality. To obtain insights into how the insufficient decrease occurs, we comprehensively analyzed differences in the microbiological and chemical properties of sunki made from three different turnip harvests and found a significant difference in their final pH. Microbiota and metabolome analyses revealed that the insufficient pH decrease showed strong relationships with the chemical composition (low lactic acid and high ammonia levels) and bacterial community structure (low Lactobacillus and high Limosilactobacillus). In vitro sunki fermentation experiments demonstrated that accumulated ammonia was associated with a decrease in glutamine and an increase in glutamic acid. Limosilactobacillus reuteri, a species of lactic acid bacteria possessing heterolactic metabolism, was suggested to be mainly responsible for insufficient decrease in pH related to accumulated ammonia during sunki fermentation.

Lactational transfer of sulforaphane-N-acetylcysteine in vivo and in human breast milk

Sulforaphane (SFN) is a bioactive phytonutrient found in cruciferous vegetables. There is a lack of detailed information on the lactational transfer of SFN and SFN metabolites, and potential pharmacological effects on breastfeeding infants. We carried out two maternal supplementation studies in a mouse model, wherein lactating dams received either vehicle, 300 or 600 ppm SFN from postnatal day (PND) 1 to 5, or in a second experiment, vehicle or 600 ppm SFN from PND 1 to 14. The parent compound was only detectable in milk and plasma from dams receiving 600 ppm SFN for five days. The predominant metabolite SFN-N-acetylcysteine (SFN-NAC) was readily detected in milk from dams receiving 300 and 600 ppm SFN for five days or 600 ppm for 14 days. Maternal SFN-NAC plasma levels were elevated in both 600 ppm groups. Maternal hepatic and pulmonary expression of NRF2-related genes, Nqo1, Gsta2, Gstm1, and Gstp1, were significantly increased, generally following a dose-response; however, offspring induction varied. PND5 neonates in the 600-ppm group exhibited significantly elevated expression of Nqo1, Gsta2, and Gstp1 in liver, and Gstm1 and Gstp1 in lung. Findings support maternal dietary supplementation with SFN induces NRF2-related gene expression in neonates via lactational transfer of SFN-NAC. However, NQO1 enzyme activity was not significantly elevated, highlighting the need to optimize dosing strategy. Additionally, in a pilot investigation of lactating women consuming a typical diet, without any purified SFN supplementation, 7 out of 8 breast milk samples showed SFN-NAC above the limit of quantification (LOQ). Notably, the one sample below the LOQ was collected from the only participant who reported no consumption of cruciferous vegetables in the past 24 h. The parent compound was not detected in any of the human breast milk samples. Overall, these data indicate lactational transfer of SFN-NAC at dietary relevant levels. Future studies are needed to evaluate pharmacokinetics and pharmacodynamics of lactational transfer for potential preventive or therapeutic effects in breastfeeding children.

Sustainable treatment and nutrient recovery from leafy waste through vermicomposting

The present investigation was carried out to evaluate the vermicomposting potential of two cruciferous vegetables' residual biomasses under laboratory conditions. Cabbage and cauliflower residual biomasses were spiked with 60% cow dung and vermicomposted for 90 days. The results showed a decrease in pH (5.3-9.8%), Total Organic Carbon (36.7-42.8%); increase in Electrical Conductivity (33-99.4%) and ash content (144.7-187.8%) after vermicomposting. Significant reduction in C:N ratio (49.5-76.4%) and C:P ratio (62.8-66.04%), increase in Total Kjeldahl Nitrogen (49.3-85.3%), Total Available Phosphorus (68.2-98.1%), Total Potassium (91.8-120.3%) were observed. FT-IR spectra of the vermicomposts had lesser band heights and peak intensities than raw materials. This evidenced decomposition of organic compounds and vermicompost stability. Germination Index values was calculated to determine the phytotoxicity level. Earthworms' growth and prolificacy was evaluated in terms of biomass gain, cocoons production and worm growth rate. Finally, it was inferred that cruciferous vegetables' biomass can be used for vermicomposting. The cauliflower residual biomass has shown better decomposition efficiency than cabbage residual biomass.

Cruciferous vegetable and isothiocyanate intake and multiple health outcomes

Isothiocyanates, bioactive phytochemicals of cruciferous vegetables, have chemopreventative efficacy. To clarify evidence of associations between cruciferous vegetable and isothiocyanate intake and various health outcomes, we conducted an umbrella review of meta-analyses and systematic reviews in humans. A total of 413 articles were identified, and 57 articles with 24 health outcomes were included. Consumption of cruciferous vegetables was associated with a reduced risk of all-cause mortality, cancers, and depression. Dose-response analyses revealed that a per 100 g/d increment was associated with a 10% decrease in the risk of all-cause mortality. Warfarin resistance caused by vitamin K-rich broccoli was reported. Caution was warranted for those allergies/hypersensitivities to the Brassica genus. The intake of cruciferous vegetables is generally safe and beneficial in humans. However the quality of the majority (68%) of evidence was low.

Dietary supplementation with sulforaphane ameliorates skin aging through activation of the Keap1-Nrf2 pathway

Visible impairments in skin appearance, as well as a subtle decline in its functionality at the molecular level, are hallmarks of skin aging. Activation of the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-pathway, which is important in controlling inflammation and oxidative stress that occur during aging, can be triggered by sulforaphane (SFN), an isothiocyanate found in plants from the Brassicaceae family. This study aimed to assess the effects of SFN intake on age-related skin alterations. Male C57BL6 young (2 months) and old (21 months) mice were treated for 3 months with SFN diet (442.5 mg per kg) or control diet. The antioxidant capacities of the skin were increased in old SFN-treated animals as measured by mRNA levels of Nrf2 (P<.001) and its target genes NQO1 (P<.001) and HO1 (P<.01). Protein expression for Nrf2 was also increased in old SFN fed animals (P<.01), but not the protein expression of NQO1 or HO1. Additionally, ROS and MMP9 protein levels were significantly decreased (P<.05) in old SFN fed animals. Histopathological analysis confirmed that there was no difference in epidermal thickness in old, when compared to young, SFN treated animals, while the dermal layer thickness was lower in old vs. young, treated animals (P<.05). Moreover, collagen deposition was improved with SFN treatment in young (P<.05) and structurally significantly improved in the old mice (P<.001). SFN dietary supplementation therefore ameliorates skin aging through activation of the Nrf2-pathway.

Metabolomic evaluation of different starter culture effects on water-soluble and volatile compound profiles in nozawana pickle fermentation

Metabolomic characterization of a lactic-fermented pickle of nozawana (Brassica rapa L. var. hakabura) was conducted to evaluate the effects of different starter culture strains on the chemical profiles. We compared the profiles of water-soluble and volatile compounds obtained by non-targeted nuclear magnetic resonance and solid-phase microextraction gas chromatography/mass spectrometry analyses. Principal component analyses indicated that the fermented samples differed significantly in terms of the levels of various compounds, including taste- and aroma-active components, such as water-soluble residual sugars, organic acids, mannitol, ethanol, dihydroxyacetone, ornithine, γ-aminobutyric acid, choline, volatile isothiocyanates, 3,4-epithiobutyl cyanide, 2,3-butanedione, acetoin, ethyl acetate, dimethyl trisulfide, and S-methyl thioacetate. Fermentation with a Latilactobacillus curvatus culture was associated with a unique metabolite profile characterized by higher levels of isothiocyanates and hexanoic acid and lower levels of lactic acid, acetic acid, acetoin, and 2,3-butanedione. These variations in the chemical profile might be associated with different qualities in fermented nozawana pickle products.

Consumption of cruciferous vegetables and the risk of bladder cancer in a prospective US cohort: data from the NIH-AARP diet and health study

BACKGROUND

Abundant pre-clinical data suggest that consumption of cruciferous vegetables might protect against bladder cancer. While small-scale clinical evidence supports this hypothesis, population-level data is lacking. We tested the hypothesis that consumption of cruciferous vegetables is associated with a lower risk of bladder cancer in a large population-based study.

METHODS

We investigated the association between dietary consumption of cruciferous vegetables and the risk of bladder cancer in the NIH-American Association of Retired Persons (AARP) Diet and Health Study. Diet at baseline was collected with self-administered food-frequency questionnaires. Bladder cancer diagnoses were identified through linkage with state cancer registries. Hazard ratio (HR) and 95% confidence intervals (CI) were estimated with Cox proportional hazards models.

RESULTS

Our analysis included 515,628 individuals. Higher intake of cruciferous vegetables, both overall and when stratified by variety (broccoli vs. brussels sprouts vs. cauliflower), were not associated with bladder cancer risk for men or women. A history of smoking did not affect the results.

CONCLUSIONS

Our study shows no association between dietary consumption of cruciferous vegetables and incident bladder cancer.

Post-Diagnostic Dietary and Lifestyle Factors and Prostate Cancer Recurrence, Progression, and Mortality

PURPOSE OF REVIEW

This study aimed to summarize evidence published between 1999 and June 2020 examining diet and lifestyle after prostate cancer (PC) diagnosis in relation to risk of biochemical recurrence, PC progression, and PC-specific mortality.

RECENT FINDINGS

Secondary prevention is an important research area in cancer survivorship. A growing number of studies have reported associations between post-diagnostic modifiable behaviors and risk of PC outcomes. Evidence on modifiable lifestyle factors and PC remains limited. Where multiple studies exist, findings are often mixed. However, studies consistently suggest that smoking and consumption of whole milk/high-fat dairy are associated with higher risk of PC recurrence and mortality. In addition, physical activity and ½ to 1 glass of red wine/day have been associated with lower risk of recurrence and PC-specific mortality. Greater inclusion of racially/ethnically diverse groups in future research is necessary to understand these relationships in populations most impacted by adverse PC outcomes.

Intake of total cruciferous vegetable and its contents of glucosinolates and isothiocyanates, glutathione S-transferases polymorphisms and breast cancer risk: a case-control study in China

Cruciferous vegetables contain high levels of glucosinolates (GSL) and isothiocyanates (ITC). ITC are known to induce glutathione S-transferases (GST) and thus exert their anticarcinogenic effects. This study explored the combined effects of cruciferous vegetable, GSL and ITC intake and GST polymorphisms on breast cancer risk. A total of 737 breast cancer cases and 756 controls were recruited into this case-control study. OR and 95 % CI were assessed by multivariable logistic regression. Higher cruciferous vegetable, GSL and ITC intakes were inversely associated with breast cancer risk, with adjusted OR of 0·48 (95 % CI 0·35, 0·65), 0·54 (95 % CI 0·40, 0·74) and 0·62 (95 % CI 0·45, 0·84), respectively. Compared with women carrying the GSTP1 rs1695 wild AA genotype and high cruciferous vegetable, GSL or ITC intake, carriers of the AA genotype with low cruciferous vegetable, GSL and ITC intake had greater risk of breast cancer, with adjusted OR of 1·43 (95 % CI 1·01, 1·87), 1·34 (95 % CI 1·02, 1·75) and 1·37 (95 % CI 1·05, 1·80), respectively. Persons with the GSTM1-null genotype and lower intake of cruciferous vegetables, GSL and ITC had higher risk of breast cancer than those with the GSTM1-present genotype and higher intake, with OR of 1·42 (95 % CI 1·04, 1·95), 1·43 (95 % CI 1·05, 1·96) and 1·45 (95 % CI 1·06, 1·98), respectively. Among women possessing the GSTT1-present genotype, low intake of cruciferous vegetables, GSL or ITC was associated with higher risk of breast cancer. But these interactions were non-significant. This study indicated that there were no significant interactions between cruciferous vegetable, GSL or ITC intake and GST polymorphisms on breast cancer risk.

Cruciferous vegetable intake is inversely associated with extensive abdominal aortic calcification in elderly women: a cross-sectional study

We have previously shown that higher intake of cruciferous vegetables is inversely associated with carotid artery intima-media thickness. To further test the hypothesis that an increased consumption of cruciferous vegetables is associated with reduced indicators of structural vascular disease in other areas of the vascular tree, we aimed to investigate the cross-sectional association between cruciferous vegetable intake and extensive calcification in the abdominal aorta. Dietary intake was assessed, using a FFQ, in 684 older women from the Calcium Intake Fracture Outcome Study. Cruciferous vegetables included cabbage, Brussels sprouts, cauliflower and broccoli. Abdominal aortic calcification (AAC) was scored using the Kauppila AAC24 scale on dual-energy X-ray absorptiometry lateral spine images and was categorised as ‘not extensive’ (0–5) or ‘extensive’ (≥6). Mean age was 74·9 (sd 2·6) years, median cruciferous vegetable intake was 28·2 (interquartile range 15·0–44·7) g/d and 128/684 (18·7 %) women had extensive AAC scores. Those with higher intakes of cruciferous vegetables (>44·6 g/d) were associated with a 46 % lower odds of having extensive AAC in comparison with those with lower intakes (<15·0 g/d) after adjustment for lifestyle, dietary and CVD risk factors (OR_{Q4 v. Q1} 0·54, 95 % CI 0·30, 0·97, P = 0·036). Total vegetable intake and each of the other vegetable types were not related to extensive AAC (P > 0·05 for all). This study strengthens the hypothesis that higher intake of cruciferous vegetables may protect against vascular calcification.

A randomised controlled crossover trial investigating the short-term effects of different types of vegetables on vascular and metabolic function in middle-aged and older adults with mildly elevated blood pressure: the VEgetableS for vaScular hEaLth (VESSEL) study protocol

Background

A diet rich in fruits and vegetables is recommended for cardiovascular health. However, the majority of Australians do not consume the recommended number of vegetable servings each day. Furthermore, intakes of vegetables considered to have the greatest cardiovascular benefit are often very low. Results from prospective observational studies indicate that a higher consumption of cruciferous vegetables (e.g. broccoli, cabbage, cauliflower) is associated with lower cardiovascular disease risk. This may be due to the presence of specific nutrients and bioactive compounds found almost exclusively, or at relatively high levels, in cruciferous vegetables. Therefore, the aim of this randomised controlled crossover trial is to determine whether regular consumption of cruciferous vegetables results in short-term improvement in measures related to cardiovascular disease risk, including ambulatory blood pressure, arterial stiffness, glycaemic control, and circulating biomarkers of oxidative stress and inflammation.

Methods

Twenty-five participants (50–75 years) with mildly elevated blood pressure (systolic blood pressure 120–160 mmHg) will complete two 2-week intervention periods in random order, separated by a 2-week washout period. During the intervention period, participants will consume 4 servings (~ 300 g) of cruciferous vegetables per day as a soup (~ 500–600 mL/day). The ‘control’ soup will consist of other commonly consumed vegetables (potato, sweet potato, carrot, pumpkin). Both soups will be approximately matched for energy, protein, fat, and carbohydrate content. All measurements will be performed at the beginning and end of each intervention period.

Discussion

The findings of this study will provide evidence regarding the potential cardiometabolic health benefits of cruciferous vegetables, which may contribute to the revision of dietary and clinical guidelines.

Trial registration

The trial was registered with the Australian New Zealand Clinical Trial Registry on 19th September 2019 (ACTRN12619001294145).

The role of micronutrients in thyroid dysfunction

Thyroid hormones are essential for normal growth and development in children. Nutritional factors are closely related to thyroid dysfunction due to deviation from normal physiology of the gland. Iodine, a main constituent of thyroid hormones (T3 and T4), deficiency is one of the commonest causes of hypothyroidism in children and adults, worldwide. Other micronutrients, such as Cruciferous vegetables, Pearl Millet, Soy products and Cassava, were also attributed to cause thyroid dysfunction. Environmental factors, namely, contamination of water with goitrogens could also contribute to the aetiology of goitre in some endemic areas. Dietary advice and avoidance of excessive use of goitrogens in diet are part of guidance on nutritional safety that needs to be established, especially in the areas of endemicity.

The potential use of l-sulforaphane for the treatment of chronic inflammatory diseases: A review of the clinical evidence

According to the World Health Organisation, 70% of all deaths globally can be attributed to chronic inflammatory diseases such as rheumatoid arthritis, inflammatory bowel disease, respiratory conditions, cardiovascular diseases, diabetes and cancer. Chronic inflammation has a significant impact on the quality of life of affected individuals with an increased risk of developing other chronic inflammatory diseases. Given the limitations of current pharmaceuticals, there is an intense research interest in identifying novel dietary interventions that can regulate and alleviate inflammation. A diet rich in cruciferous vegetables has been extensively studied for its immediate and long-term health benefits, particularly in the context of cardiovascular disease and cancer. Cruciferous vegetables contain the precursor glucoraphanin, which is hydrolysed upon consumption to form l-sulforaphane (LSF), the primary active compound that mediates potential cardio-protective and anti-carcinogenic effects. LSF has been shown to have beneficial effects in vitro and in animal studies through its classical antioxidant and anti-inflammatory properties, and more recently its chromatin modifying effects. This review discusses the clinical evidence to date in relation to the use of LSF in the context of chronic inflammatory diseases as well as provide key mechanistic insights for these effects.

Feasibility Outcomes of a Pilot Randomized Clinical Trial to Increase Cruciferous and Green Leafy Vegetable Intake in Posttreatment Head and Neck Cancer Survivors

BACKGROUND

Higher intakes of cruciferous vegetables (CVs) and green leafy vegetables (GLVs) in observational studies are associated with improvements in survival and cancer-related biomarkers in patients diagnosed with head and neck cancer (HNC). These results have yet to be corroborated in a randomized clinical trial (RCT).

OBJECTIVE

Determine the feasibility of implementing a 12-week RCT to increase CV and GLV intake in posttreatment HNC survivors.

DESIGN AND PARTICIPANTS

This was a two-arm RCT conducted among 24 posttreatment HNC survivors. Survivors were recruited from a southeastern, National Cancer Institute-designated Comprehensive Cancer Center between January 2015 and September 2016.

INTERVENTION

There were two groups: (1) an experimental group (n=12) receiving weekly 15- to 30-minute telephone dietary counseling from a registered dietitian nutritionist stressing 2.5 cups per week CVs and 3.5 cups per week GLVs, and (2) an attention control group (n=12) receiving weekly 15- to 30-minute telephone dietary counseling from a registered dietitian nutritionist focusing on general healthy eating for cancer survivors. Participants completed a baseline survey, three 24-hour dietary recalls, phlebotomy, and anthropometric measures prior to randomization and at the end of the 12-week study period. The experimental group also completed weekly vegetable record recalls.

MAIN OUTCOME MEASURES

Primary outcomes included feasibility, recruitment, retention, adherence, and safety. Secondary outcomes included inflammatory markers and carotenoids.

STATISTICAL ANALYSES PERFORMED

Descriptive statistics were generated for demographic, epidemiological, and clinical variables as well as the primary feasibility outcomes. Between- and within-group comparisons of mean serum cytokine and carotenoid levels were performed using appropriate statistical tests depending on their respective distributions for the purpose of generating preliminary effect sizes.

RESULTS

Overall, 350 incident HNC cases were screened for eligibility, and 98 were eligible for study participation. Reasons for ineligibility and exclusion included deceased (n=93); wrong or inactive telephone numbers, or unable to be reached, or lost to follow-up (n=93); not meeting inclusion criteria (n=39); and too ill to participate (n=27). Of the 98 eligible HNC cases, 24 agreed to participate, for an enrollment rate of 25%. The most common reason for nonparticipation was distance (n=48), as participants were asked to report for two on-site assignments. The retention rate was 96%. Mean intervention adherence rates for weekly goals were 67% CV, 74% GLV, and 71% overall. Completion rate of weekly counseling calls was 90%. The experimental group reported an overall mean increase of 5.5 cups GLV and 3.5 cups CV per week from baseline intake, respectively. No significant between- or within-arm differences were observed for inflammatory markers or carotenoids.

CONCLUSION

A posttreatment intervention aimed at increasing CV and GLV intake in HNC survivors is feasible. A larger RCT is needed to assess the efficacy of this intervention on disease outcomes.

Broccoli consumption affects the human gastrointestinal microbiota

The human gastrointestinal microbiota is increasingly linked to health outcomes; however, our understanding of how specific foods alter the microbiota is limited. Cruciferous vegetables such as broccoli are a good source of dietary fiber and phytonutrients, including glucosinolates, which can be metabolized by gastrointestinal microbes. This study aimed to determine the impact of broccoli consumption on the gastrointestinal microbiota of healthy adults. A controlled feeding, randomized, crossover study consisting of two 18-day treatment periods separated by a 24-day washout was conducted in healthy adults (n=18). Participants were fed at weight maintenance with the intervention period diet including 200 g of cooked broccoli and 20 g of raw daikon radish per day. Fecal samples were collected at baseline and at the end of each treatment period for microbial analysis. Beta diversity analysis indicated that bacterial communities were impacted by treatment (P=.03). Broccoli consumption decreased the relative abundance of Firmicutes by 9% compared to control (P=.05), increased the relative abundance of Bacteroidetes by 10% compared to control (P=.03) and increased Bacteroides by 8% relative to control (P=.02). Furthermore, the effects were strongest among participants with body mass index <26 kg/m², and within this group, there were associations between bacterial relative abundance and glucosinolate metabolites. Functional prediction revealed that broccoli consumption increased the pathways involved in the functions of the endocrine system (P=.05), transport and catabolism (P=.04), and energy metabolism (P=.01). These results reveal that broccoli consumption affects the composition and function of the human gastrointestinal microbiota.

[A nested case-control study of cruciferous vegetables intake, urinary isothiocyanates level and lung cancer risk among men in urban Shanghai]

Objective: To investigate the association between consumption of cruciferous vegetables (CV), level of urinary isothiocyanates (ITC) and the risk of lung cancer among man in urban Shanghai. Methods: A nested case-control study was conducted within the Shanghai Men's Health Study. Using incidence density sampling with a 2∶1 control to case selection ratio, 885 controls were selected to match 443 lung cancer cases diagnosed prior December 31, 2010. A food-frequency questionnaire was administered to estimate CV consumption. The high performance liquid chromatography method was applied to measure urinary ITC level. The CV intake and urinary ITC level were divided into quartiles according to distribution of control group. The lowest quartile was as a reference group. Conditional logistic regression model was used to analyze the relationship between CV intake, urinary ITC level and the risk of lung cancer. Results: The cruciferous vegetables intake median (P(25), P(75)) in cases and controls were 80.05 (46.89, 129.04) and 97.68 (55.25, 151.72) g/d (Z=-3.93, P<0.001). The urinary ITC level were 1.256 (0.474, 3.836) and 1.244 (0.484, 3.004) μmol/g Cr (Z=-0.39, P=0.697). After adjusting for potential confounding factors such as age, education level, smoking and alcohol consumption, for urinary ITC level, the OR(95%CI) for the highest quartile(≥3.004 μmol/g Cr) was 1.25 (0.87-1.80) compared with the lowest quartile(<0.484 μmol/g). For CV intake, the OR(95%CI) for the highest quartile(≥151.71 g/d) was 0.66 (0.43-1.02) compared with the lowest quartile(<55.25 g/d). Conclusion: No association was found between the CV intake, urinary ITC level and lung cancer risk in men.

Apoptosis as a Mechanism of the Cancer Chemopreventive Activity of Glucosinolates: a Review

Cruciferous vegetables are a rich source of glucosinolates that have established anti-carcinogenic activity. Naturally-occurring glucosinolates and their derivative isothiocyanates (ITCs), generated as a result of their enzymatic degradation catalysed by myrosinase, have been linked to low cancer incidence in epidemiological studies, and in animal models isothiocyanates suppressed chemically-induced tumorigenesis. The prospective effect of isothiocyanates as anti-carcinogenic agent has been much explored as cytotoxic against wide array of cancer cell lines and being explored for the development of new anticancer drugs. However, the mechanisms of isothiocyanates in inducing apoptosis against tumor cell lines are still largely disregarded. A number of mechanisms are believed to be involved in the glucosinolate-induced suppression of carcinogenesis, including the induction of apoptosis, biotransformation of xenobiotic metabolism, oxidative stress, alteration of caspase activity, angiogenesis, histone deacytylation and cell cycle arrest. The molecular mechanisms through which isothiocyanates stimulate apoptosis in cancer cell lines have not so far been clearly defined. This review summarizes the underlying mechanisms through which isothiocyanates modify the apoptotic pathway leading to cell death.

Cruciferous vegetable intake and mortality in middle-aged adults: A prospective cohort study

BACKGROUND & AIMS

Cruciferous vegetables contain isothiocyanates, which effectively reduce inflammation and oxidative stress related to chronic diseases, inhibit the bioactivation of procarcinogens, and enhance the excretion of carcinogens. However, at present, no large cohort studies have investigated the effect of cruciferous vegetable on mortality. We aimed to examine the association between cruciferous vegetable intake and all-cause mortality, namely cancer, heart disease, cerebrovascular disease, and injuries, in a large cohort study conducted between 1990 and 1993, in Japan.

METHODS

The analysis included 88,184 participants (age: 45-74 years) with no history of cancer, myocardial infarction, and stroke. Participants were tracked for a median of 16.9 years, during which 15,349 deaths were occurred. The association between cruciferous vegetable intake and risk of all-cause and cause-specific mortality was determined by Cox proportional hazard regression analysis to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs), after adjustment for potential confounding factors.

RESULTS

An inverse association was found between cruciferous vegetable intake and total mortality in both gender. HRs (95% CI) for all-cause mortality in the highest compared to the lowest quintile were 0.86 (0.80, 0.93) for men (P = 0.0002 for trend) and 0.89 (0.81, 0.98) for women (P = 0.03 for trend). Cruciferous vegetable intake was associated with lower cancer mortality in men, as well as with heart disease-, cerebrovascular disease-, and injury-related mortality in women.

CONCLUSIONS

This prospective study suggests that a higher cruciferous vegetables intake is associated with reduced risk of all-cause mortality.

Dietary intake of soy and cruciferous vegetables and treatment-related symptoms in Chinese-American and non-Hispanic White breast cancer survivors

PURPOSE

This project was undertaken to examine the association between dietary intake of soy or cruciferous vegetables and breast cancer treatment-related symptoms among Chinese-American (CA) and Non-Hispanic White (NHW) breast cancer survivors.

METHODS

This cross-sectional study included 192 CA and 173 NHW female breast cancer survivors (stages 0-III, diagnosed between 2006 and 2012) recruited from two California cancer registries, who had completed primary treatment. Patient-reported data on treatment-related symptoms and potential covariates were collected via telephone interviews. Dietary data were ascertained by mailed questionnaires. The outcomes evaluated were menopausal symptoms (hot flashes, night sweats, vaginal dryness, vaginal discharge), joint problems, fatigue, hair thinning/loss, and memory problems. Associations between soy and cruciferous vegetables and symptoms were assessed using logistic regression. Analyses were further stratified by race/ethnicity and endocrine therapy usage (non-user, tamoxifen, aromatase inhibitors).

RESULTS

Soy food and cruciferous vegetable intake ranged from no intake to 431 and 865 g/day, respectively, and was higher in CA survivors. Higher soy food intake was associated with lower odds of menopausal symptoms (≥ 24.0 vs. 0 g/day, OR 0.51, 95% CI 0.25, 1.03), and fatigue (≥ 24.0 vs. 0 g/day, OR 0.43, 95% CI 0.22, 0.84). However, when stratified by race/ethnicity, associations were statistically significant in NHW survivors only. Compared with low intake, higher cruciferous vegetable intake was associated with lower odds of experiencing menopausal symptoms (≥ 70.8 vs. < 33.0 g/day, OR 0.50, 95% CI 0.25, 0.97) in the overall population.

CONCLUSIONS

In this population of breast cancer survivors, higher soy and cruciferous vegetable intake was associated with less treatment-related menopausal symptoms and fatigue.

Identification and analysis of a mercapturic acid conjugate of indole-3-methyl isothiocyanate in the urine of humans who consumed cruciferous vegetables

Glucobrassicin, a quantitatively significant constituent of Brassica vegetables, gives rise to indole-3-carbinol (I3C) and its dimer di-indolylmethane (DIM) when the vegetables are chewed. I3C and DIM have been extensively studied with respect to their anti-carcinogenic properties. However, the presumed intermediate isothiocyanate in their formation, indole-3-methyl isothiocyanate (IMITC), has to our knowledge never been observed, despite the fact that isothiocyanates derived from cruciferous vegetables are known to have anti-carcinogenic properties. Therefore, we investigated the formation and presence in human urine of IMITC by analyzing for its N-acetylcysteine conjugate, IMITC-NAC, in order to gain a more complete understanding of the biochemical pathways leading to formation of I3C and DIM upon consumption of vegetables rich in glucobrassicin. Standard IMITC-NAC was synthesized and its structure confirmed by NMR and MS. IMITC-NAC was identified in extracts of Brussels sprouts chopped in the presence of N-acetylcysteine. An LC-ESI-MS/MS-SRM method for analysis of IMITC-NAC, with [¹³C,¹⁵N]IMITC-NAC as internal standard, was developed and validated. Then, ten subjects (7 females) consumed a salad of Brussels sprouts and cabbage (containing 100-500μmol glucobrassicin) once daily for 3days. Urine was collected at intervals up to 24h after vegetable consumption. Levels of IMITC-NAC in the urine of these 10 subjects ranged from 0.2 to 30.2pmol/mL urine. These results provide the first evidence for the presumed intermediacy of IMITC in the formation of I3C and DIM in humans who consumed Brussels sprouts and cabbage as a source of glucobrassicin.

Relationship between Chemical Structure and Antimicrobial Activities of Isothiocyanates from Cruciferous Vegetables against Oral Pathogens

We evaluated the potentials of 10 isothiocyanates (ITCs) from cruciferous vegetables and radish root hydrolysate for inhibiting the growth of oral pathogens, with an emphasis on assessing any structure-function relationship. Structural differences in ITCs impacted their antimicrobial activities against oral pathogens differently. The indolyl ITC (indol-3-carbinol) was the most potent inhibitor of the growth of oral pathogens, followed by aromatic ITCs (benzyl ITC (BITC) and phenylethyl ITC (PEITC)) and aliphatic ITCs (erucin, iberin, and sulforaphene). Sulforaphene, which is similar in structure, but has one double bond, showed higher antimicrobial activity than sulforaphane. Erucin, which has a thiol group, showed higher antimicrobial activity than sulforaphane, which has a sulfinyl group. BITC and iberin with a short chain exhibited higher antimicrobial potential than PEITC and sulforaphane with a longer chain, respectively. ITCs have strong antimicrobial activities and may be useful in the prevention and management of dental caries.

Effect of Cruciferous Vegetable Intake on Oxidative Stress Biomarkers: Differences by Breast Cancer Status

This post hoc analysis examined cruciferous vegetable intake on urinary oxidative metabolites in postmenopausal women. Intervention participants (n = 69) received cruciferous vegetables (≥14 cups/week) during a 3-week period. First morning urine measured 8-isoprostane and 8-hydroxy-2'-deoxyguanosine. Dietary intake was estimated using 24-h recalls. When stratified by history of breast cancer, those with breast cancer had significantly lower post-intervention urinary 8-hydroxy-2'-deoxyguanosine values in the intervention arm versus. the control arm (1.1 ng/mL vs. 3.2 ng/mL, p = .01) after adjustment for baseline 8-hydroxy-2'-deoxyguanosine. This was not observed in those without breast cancer. Further work is needed to understand the role of breast cancer in these relationships.

The impact of cruciferous vegetable isothiocyanates on histone acetylation and histone phosphorylation in bladder cancer

Cruciferous vegetable intake is associated with reduced risk of bladder cancer, yet mechanisms remain unclear. Cruciferous vegetable isothiocyanates (ITCs), namely sulforaphane (SFN) and erucin (ECN), significantly inhibit histone deacetylase (HDAC) activity in human bladder cancer cells representing superficial to invasive biology (59-83% inhibition with 20μM, 48h treatment), and in bladder cancer xenografts (59±3% ECN inhibition). Individual HDACs inhibited by SFN and ECN include HDACs 1, 2, 4 and 6. Interestingly, global acetylation status of histones H3 or H4 remain unaltered. The interplay between HDAC inhibition and modest modulation of AcH3 and AcH4 status is partially explained by decreased histone acetyl transferase activity (48.8±5.3%). In contrast, a significant decrease in phosphorylation status of all isoforms of histone H1 was observed, concomitant with increased phosphatase PP1β and PP2A activity. Together, these findings suggest that ITCs modulate histone status via HDAC inhibition and phosphatase enhancement. This allows for reduced levels of histone H1 phosphorylation, a marker correlated with human bladder cancer progression. Therefore, ITC-mediated inhibition of histone H1 phosphorylation presents a novel direction of research in elucidating epidemiological relationships and supports future food-based prevention strategies.

SIGNIFICANCE

Collectively, our findings suggest that the cruciferous vegetable isothiocyanates: sulforaphane (SFN) and erucin (ECN), impact histones status in bladder cancer cells by modulating specific HDACs and HATs, and enhancing phosphatase activity, resulting in reduction of histone H1 phosphorylation. These findings are significant due to the fact that our previous work positively correlated histone H1 phosphorylation with bladder cancer carcinogenesis and progression. Therefore, we propose that SFN and ECN may inhibit bladder carcinogenesis via epigenetic modulation of gene expression associated with histone H1 phosphorylation. These efforts may elucidate biomarkers useful in epidemiologic studies related to cruciferous vegetable intake and cancer risk or provide intermediate biomarkers for food-based clinical intervention studies in high-risk cohorts.

Transfer of radiocesium from rhizosphere soil to four cruciferous vegetables in association with a Bacillus pumilus strain and root exudation

This study was carried out to assess the effect of Bacillus pumilus on the roots of four cruciferous vegetables with different root structures in regard to enhancement of ¹³⁷Cs bioavailability in contaminated rhizosphere soil. Results revealed that B. pumilus inoculation did not enhance the plant biomass of vegetables, although it increased root volume and root surface areas of all vegetables except turnip. The pH changes due to rhizosphere acidification by B. pumilus inoculation and root exudation did not affect the bioavailability of ¹³⁷Cs. However, concentrations of ¹³⁷Cs in plant tissues and soil-to-plant transfer values increased as a result of the larger root volume and root surface area of vegetables due to inoculation. Moreover, leafy vegetables, which possessed larger root volume and root surface areas, had a higher ¹³⁷Cs transfer value than root vegetables.

Consumption of citrus and cruciferous vegetables with incident type 2 diabetes mellitus based on a meta-analysis of prospective study

BACKGROUND

Observational studies and meta-analyses suggested that increased total fruits and vegetables consumption have a protective role in incidence of type 2 diabetes mellitus (T2DM). However, we still don't know whether the subtypes, such as citrus fruits and cruciferous vegetables (CV), have a preventive role.

METHODS

We systematically searched the MEDLINE and EMBASE databases up to December 31, 2014. Summary relative risks (SRRs) and 95% confidence intervals (CIs) were calculated using random-effects models.

RESULTS

Seven distinct prospective cohort studies (five articles) were identified for this study. A total of 16,544 incident cases of type 2 diabetes were ascertained among 306,723 participants with follow-up periods ranging from 4.6 to 24 years. Based on four prospective cohort studies, we found that overall, consumption of CV had a protective role in the T2DM incidence (highest vs. lowest analysis: SRR=0.84, 95% CI: 0.73 to 0.96), with evidence of significant heterogeneity (P=0.09, I(2)=54.4%). This association was independent of the main risk factors for cardiovascular disease: smoking, alcohol use, BMI, and physical activity etc. Consumption of citrus fruits did not have a protective role in the T2DM development (highest vs. lowest analysis: SRR=1.02, 95% CI: 0.96 to 1.08), with no evidence of significant heterogeneity (P=0.49, I(2)=0).

CONCLUSIONS

Higher consumption of CV, but not citrus fruits, is associated with a significantly decreased risk of type 2 diabetes. Further large prospective studies are needed to elucidate both relationships.

Associations between cruciferous vegetable intake and selected biomarkers among women scheduled for breast biopsies

OBJECTIVE

To examine the relationship between dietary cruciferous vegetable intake and selected tumour biomarkers for histone acetylation (H3K9ac, H3K18ac, HDAC3 and HDAC6), proliferation (Ki-67) and cell-cycle regulation (p21) from breast tissue.

DESIGN

The study used baseline data of women recruited to participate in a clinical trial of sulforaphane supplement. Dietary cruciferous vegetable intake was collected through a validated Arizona Cruciferous Vegetable Intake Questionnaire. Breast tissue was obtained from biopsy samples. Spearman correlations were calculated between intake of specific cruciferous vegetables and biomarkers. Tissue biomarkers were log2-transformed to obtain approximate normality. Linear regression analyses were conducted to examine associations between cruciferous vegetable intake and biomarkers adjusting for age and use of non-steroidal anti-inflammatory drugs. False discovery rate (FDR) was used to account for multiple comparisons.

SETTING

Clinical trial baseline.

SUBJECTS

Fifty-four women who had abnormal mammogram findings and were scheduled for breast biopsy.

RESULTS

Mean intake of total cruciferous vegetables from all food sources was 81·7 (sd 57·3) g/d. Mean urinary total sulforaphane metabolites was 0·08 (sd 0·07) µm/mm creatinine. Total cruciferous vegetable intake was inversely associated with Ki-67 protein expression in breast ductal carcinoma in situ (DCIS) tissue (β=-0·004; se=0·001; FDR q value=0·03), but not in benign or invasive ductal carcinoma (IDC) tissue. No association was found for other biomarkers measured (HDAC3, HDAC6, H3K9, H3K18 and p21) in all tissues examined (benign, DCIS and IDC).

CONCLUSIONS

The present study sought to provide additional evidence for the potential role of sulforaphane in histone acetylation and cell proliferation. Here, we report that total cruciferous vegetable intake is associated with decreased cell proliferation in breast DCIS tissue.

Transfer of radiocesium to four cruciferous vegetables as influenced by organic amendment under different field conditions in Fukushima Prefecture

Soil-to-plant transfer of radiocesium ((137)Cs) in four cruciferous vegetables as influenced by cattle manure-based compost amendment was investigated. Komatsuna, mustard, radish and turnip were cultivated in three different (137)Cs-contaminated fields at Nihonmatsu City in Fukushima Prefecture from June to August 2012. Results revealed that organic compost amendments stimulated plant biomass production and tended to induce higher (137)Cs concentration in the cruciferous vegetables in most cases. Among the studied sites, Takanishi soil possessing low exchangeable potassium (0.10 cmolc kg(-1)) was associated with an increased concentration of (137)Cs in plants. Radiocesium transfer factor (TF) values of the vegetables ranged from 0.025 to 0.119. The increase in (137)Cs TFs was dependent on larger plant biomass production, high organic matter content, and high sand content in the studied soils. Average (137)Cs TF values for all study sites and compost treatments were higher in Komatsuna (0.072) and radish (0.059), which exhibited a higher biomass production compared to mustard and turnip. The transferability of (137)Cs to vegetables from soils was in the order Komatsuna > radish > mustard > turnip. The highest (137)Cs TF value (0.071) of all vegetables was recorded for a field where the soil had high organic matter content and a high clay proportion of 470 g kg(-1) consisting of Al-vermiculite clay mineral.

Phenethyl isothiocyanate: a comprehensive review of anti-cancer mechanisms

The epidemiological evidence suggests a strong inverse relationship between dietary intake of cruciferous vegetables and the incidence of cancer. Among other constituents of cruciferous vegetables, isothiocyanates (ITC) are the main bioactive chemicals present. Phenethyl isothiocyanate (PEITC) is present as gluconasturtiin in many cruciferous vegetables with remarkable anti-cancer effects. PEITC is known to not only prevent the initiation phase of carcinogenesis process but also to inhibit the progression of tumorigenesis. PEITC targets multiple proteins to suppress various cancer-promoting mechanisms such as cell proliferation, progression and metastasis. Pre-clinical evidence suggests that combination of PEITC with conventional anti-cancer agents is also highly effective in improving overall efficacy. Based on accumulating evidence, PEITC appears to be a promising agent for cancer therapy and is already under clinical trials for leukemia and lung cancer. This is the first review which provides a comprehensive analysis of known targets and mechanisms along with a critical evaluation of PEITC as a future anti-cancer agent.

Cruciferous vegetable intake is inversely correlated with circulating levels of proinflammatory markers in women

BACKGROUND

Higher intakes of cruciferous vegetables or their constituents have been shown to lower inflammation in animal studies. However, evidence for this anti-inflammatory effect of cruciferous vegetable consumption in humans is scarce.

OBJECTIVE/DESIGN

In this cross-sectional analysis, we evaluated associations of vegetable intake with a panel of inflammatory and oxidative stress markers among 1,005 middle-aged Chinese women. Dietary intake of foods was assessed by a food frequency questionnaire.

RESULTS

Multivariable-adjusted circulating concentrations of tumor necrosis factor-α (TNF-α), interlukin-1β (IL-1β), and IL-6 were lower among women with higher intakes of cruciferous vegetables. The differences in concentrations of inflammatory biomarkers between extreme quintiles of cruciferous vegetable intake were 12.66% for TNF-α (Ptrend=0.01), 18.18% for IL-1β (Ptrend=0.02), and 24.68% for IL-6 (Ptrend=0.02). A similar, but less apparent, inverse association was found for intakes of all vegetables combined but not for noncruciferous vegetables. Levels of the urinary oxidative stress markers F2-isoprostanes and their major metabolite, 2,3-dinor-5,6-dihydro-15-F2t-IsoP, were not associated with intakes of cruciferous vegetables or all vegetables combined.

CONCLUSIONS

This study suggests that the previously observed health benefits of cruciferous vegetable consumption may be partly associated with the anti-inflammatory effects of these vegetables.

Free radical reactions with the extract of brassica family

Using different extraction protocols, the antioxidant properties of green and red cabbage extracts were evaluated in terms of the total antioxidant capacities using the 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulphonic acid) (ABTS) radical scavenging method. The results demonstrate that the total antioxidant capacity of green and red cabbages correlated well with the total phenolics and total flavonoids content present in the extracts. The ABTS radical scavenging capacity of red cabbage was much higher than that of green cabbage extract. Using time resolved absorption kinetic spectrophotometry, free radical reactions with the extracts of green and red cabbages were established. The reactions of extracts were examined using a pulse radiolysis technique. Kinetic studies indicated that extracts may act as free radical scavengers for O2(-), OH radicals and as an antioxidant to repair free-radical damage to biologically important guanosine radical.