Cruciferous Vegetables, Genetic Polymorphisms in Glutathione S-Transferases M1 and T1, and Prostate Cancer Risk

Unveiling the Effects of Cruciferous Vegetable Intake on Different Cancers: A Systematic Review and Dose-Response Meta-analysis

CONTEXT

Epidemiological studies indicated that cruciferous vegetable intake is associated with positive health outcomes. However, the role of cruciferous vegetables may have differential impacts on various cancers.

OBJECTIVE

This meta-analysis aims to review recent epidemiological studies on the link between cruciferous vegetables and various cancers. It seeks to identify the optimal intake dose and timing of cruciferous vegetables influencing their association with cancer risk.

DATA SOURCES

Studies on cruciferous vegetables and cancer were searched in PubMed, NCBI, Web of Science, and Elsevier databases from 1978 to June 2023.

DATA EXTRACTION

Extracted data from 226 relevant case-control and cohort studies were expressed by standardized mean difference and 95% CI, followed by the subgroup analysis to eliminate heterogeneity.

RESULTS

Intake of cruciferous vegetables can prevent cancers, with an odds ratio of 0.77 and risk ratio (RR) of 0.96. The intake levels of cruciferous vegetables associated with the risk of colorectal cancer, lung cancer, upper gastrointestinal cancer, gynecological cancer (ovarian cancer and endometrial cancer), bladder cancer, renal cancer, and prostate cancer were found to be 5.41 servings/week, 5.41 servings/week, 5.5 servings/week, 7.4 servings/week, 5.5 servings/week, 4.85 servings/week, and 3 servings/week, respectively. In a cohort followed for 2 to 15 years, limited consumption of cruciferous vegetables was correlated with a higher cancer RR. In the Asian population, cruciferous vegetables had a significant relationship with lung cancer, head and neck squamous cell carcinoma, and esophageal cancer. Conversely, cruciferous vegetables are predominantly associated with colorectal, renal, gynecological, and prostate cancer in the American population.

CONCLUSION

This study highlights the complex link between cruciferous vegetables and cancer, influenced by factors such as cancer type, region, intake level, and follow-up duration.

Broccoli Consumption and Risk of Cancer: An Updated Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND

The scientific literature has reported an inverse association between broccoli consumption and the risk of suffering from several types of cancer; however, the results were not entirely consistent across studies. A systematic review and meta-analysis of observational studies were conducted to determine the association between broccoli consumption and cancer risk with the aim of clarifying the beneficial biological effects of broccoli consumption on cancer.

METHODS

PubMed/MEDLINE, Web of Science, Scopus, Cochrane Library (CENTRAL), and Epistemonikos databases were searched to identify all published papers that evaluate the impact of broccoli consumption on the risk of cancer. Citation chasing of included studies was conducted as a complementary search strategy. The risk of bias in individual studies was assessed using the Newcastle-Ottawa Scale. A random-effects model meta-analysis was employed to quantitatively synthesize results, with the I2 index used to assess heterogeneity.

RESULTS

Twenty-three case-control studies (n = 12,929 cases and 18,363 controls; n = 31,292 individuals) and 12 cohort studies (n = 699,482 individuals) were included in the meta-analysis. The results suggest an inverse association between broccoli consumption and the risk of cancer both in case-control studies (OR: 0.64, 95% CI from 0.58 to 0.70, p < 0.001; Q = 35.97, p = 0.072, I2 = 30.49%-moderate heterogeneity; τ2 = 0.016) and cohort studies (RR: 0.89, 95% CI from 0.82 to 0.96, p = 0.003; Q = 13.51, p = 0.333, I2 = 11.21%-low heterogeneity; τ2 = 0.002). Subgroup analysis suggested a potential benefit of broccoli consumption in site-specific cancers only in case-control studies.

CONCLUSIONS

In summary, the findings indicate that individuals suffering from some type of cancer consumed less broccoli, suggesting a protective biological effect of broccoli on cancer. More studies, especially cohort studies, are necessary to clarify the possible beneficial effect of broccoli on several types of cancer.

The efficacy of natural bioactive compounds against prostate cancer: Molecular targets and synergistic activities

Globally, prostate cancer (PCa) is regarded as a challenging health issue, and the number of PCa patients continues to rise despite the availability of effective treatments in recent decades. The current therapy with chemotherapeutic drugs has been largely ineffective due to multidrug resistance and the conventional treatment has restricted drug accessibility to malignant tissues, necessitating a higher dosage resulting in increased cytotoxicity. Plant-derived bioactive compounds have recently attracted a great deal of attention in the field of PCa treatment due to their potent effects on several molecular targets and synergistic effects with anti-PCa drugs. This review emphasizes the molecular mechanism of phytochemicals on PCa cells, the synergistic effects of compound-drug interactions, and stem cell targeting for PCa treatment. Some potential compounds, such as curcumin, phenethyl-isothiocyanate, fisetin, baicalein, berberine, lutein, and many others, exert an anti-PCa effect via inhibiting proliferation, metastasis, cell cycle progression, and normal apoptosis pathways. In addition, multiple studies have demonstrated that the isolated natural compounds: d-limonene, paeonol, lanreotide, artesunate, and bicalutamide have potential synergistic effects. Further, a significant number of natural compounds effectively target PCa stem cells. However, further high-quality studies are needed to firmly establish the clinical efficacy of these phytochemicals against PCa.

Hydrogen sulfide and sulfaceutic or sulfanutraceutic agents: Classification, differences and relevance in preclinical and clinical studies

Hydrogen sulfide (H2S) has been extensively studied as a signal molecule in the body for the past 30 years. Researchers have conducted studies using both natural and synthetic sources of H2S, known as H2S donors, which have different characteristics in terms of how they release H2S. These donors can be inorganic salts or have various organic structures. In recent years, certain types of sulfur compounds found naturally in foods have been characterized as H2S donors and explored for their potential health benefits. These compounds are referred to as "sulfanutraceuticals," a term that combines "nutrition" and "pharmaceutical". It is used to describe products derived from food sources that offer additional health advantages. By introducing the terms "sulfaceuticals" and "sulfanutraceuticals," we categorize sulfur-containing substances based on their origin and their use in both preclinical and clinical research, as well as in dietary supplements.

Sulforaphane and bladder cancer: a potential novel antitumor compound

Bladder cancer (BC) is a common form of urinary tract tumor, and its incidence is increasing annually. Unfortunately, an increasing number of newly diagnosed BC patients are found to have advanced or metastatic BC. Although current treatment options for BC are diverse and standardized, it is still challenging to achieve ideal curative results. However, Sulforaphane, an isothiocyanate present in cruciferous plants, has emerged as a promising anticancer agent that has shown significant efficacy against various cancers, including bladder cancer. Recent studies have demonstrated that Sulforaphane not only induces apoptosis and cell cycle arrest in BC cells, but also inhibits the growth, invasion, and metastasis of BC cells. Additionally, it can inhibit BC gluconeogenesis and demonstrate definite effects when combined with chemotherapeutic drugs/carcinogens. Sulforaphane has also been found to exert anticancer activity and inhibit bladder cancer stem cells by mediating multiple pathways in BC, including phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK), nuclear factor kappa-B (NF-κB), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), zonula occludens-1 (ZO-1)/beta-catenin (β-Catenin), miR-124/cytokines interleukin-6 receptor (IL-6R)/transcription 3 (STAT3). This article provides a comprehensive review of the current evidence and molecular mechanisms of Sulforaphane against BC. Furthermore, we explore the effects of Sulforaphane on potential risk factors for BC, such as bladder outlet obstruction, and investigate the possible targets of Sulforaphane against BC using network pharmacological analysis. This review is expected to provide a new theoretical basis for future research and the development of new drugs to treat BC.

The protective role of sulforaphane and Homer1a in retinal ischemia-reperfusion injury: Unraveling the neuroprotective interplay

AIMS

Retinal ischemia/reperfusion (I/R) injury is a common pathological basis for various ophthalmic diseases. This study aimed to investigate the potential of sulforaphane (SFN) and Homer1a in regulating cell apoptosis induced by retinal I/R injury and to explore the underlying regulatory mechanism between them.

MATERIALS AND METHODS

In in vivo experiments, C57BL/6J mice and Homer1flox/-/Homer1a+/-/Nestin-Cre+/- mice were used to construct retinal I/R injury models. In vitro experiments utilized the oxygen-glucose deprivation-reperfusion (OGD/R) injury model with primary retinal ganglion cells (RGCs). The effects of Homer1a and SFN on cell apoptosis were observed through pathological analyses, flow cytometry, and visual electrophysiological assessments.

KEY FINDINGS

We discovered that after OGD/R injury, apoptosis of RGCs and intracellular Ca2+ activity significantly increased. However, these changes were reversed upon the addition of SFN, and similar observations were reproduced in in vivo studies. Furthermore, both in vivo and in vitro studies confirmed the upregulation of Homer1a after I/R, which could be further enhanced by the administration of SFN. Moreover, upregulation of Homer1a resulted in a reduction in cell apoptosis and pro-apoptotic proteins, while downregulation of Homer1a had the opposite effect. Flash visual evoked potential, oscillatory potentials, and escape latency measurements in mice supported these findings. Furthermore, the addition of SFN strengthened the neuroprotective effects in the OGD/R + H+ group but weakened them in Homer1flox/-/Homer1a+/-/Nestin-Cre+/- mice.

SIGNIFICANCE

These results indicate that Homer1a plays a significant role in the therapeutic potential of sulforaphane for retinal I/R injury, thereby providing a theoretical basis for clinical treatment.

The beneficial effect of sulforaphane on platelet responsiveness during caloric load: a single-intake, double-blind, placebo-controlled, crossover trial in healthy participants

Background and aims

As our understanding of platelet activation in response to infections and/or inflammatory conditions is growing, it is becoming clearer that safe, yet efficacious, platelet-targeted phytochemicals could improve public health beyond the field of cardiovascular diseases. The phytonutrient sulforaphane shows promise for clinical use due to its effect on inflammatory pathways, favorable pharmacokinetic profile, and high bioavailability. The potential of sulforaphane to improve platelet functionality in impaired metabolic processes has however hardly been studied in humans. This study investigated the effects of broccoli sprout consumption, as a source of sulforaphane, on urinary 11-dehydro-thromboxane B₂ (TXB₂), a stable thromboxane metabolite used to monitor eicosanoid biosynthesis and response to antithrombotic therapy, in healthy participants exposed to caloric overload.

Methods

In this double-blind, placebo-controlled, crossover trial 12 healthy participants were administered 16g of broccoli sprouts, or pea sprouts (placebo) followed by the standardized high-caloric drink PhenFlex given to challenge healthy homeostasis. Urine samples were collected during the study visits and analyzed for 11-dehydro-TXB₂, sulforaphane and its metabolites. Genotyping was performed using Illumina GSA v3.0 DTCBooster.

Results

Administration of broccoli sprouts before the caloric load reduced urinary 11-dehydro-TXB₂ levels by 50% (p = 0.018). The amount of sulforaphane excreted in the urine during the study visits correlated negatively with 11-dehydro-TXB₂ (r_s = -0.377, p = 0.025). Participants carrying the polymorphic variant NAD(P)H dehydrogenase quinone 1 (NQO1*2) showed decreased excretion of sulforaphane (p = 0.035).

Conclusion

Sulforaphane was shown to be effective in targeting platelet responsiveness after a single intake. Our results indicate an inverse causal relationship between sulforaphane and 11-dehydro-TXB₂, which is unaffected by the concomitant intake of the metabolic challenge. 11-Dehydro-TXB₂ shows promise as a non-invasive, sensitive, and suitable biomarker to investigate the effects of phytonutrients on platelet aggregation within hours.

Clinical trial registration

[https://clinicaltrials.gov/], identifier [NCT05146804].

Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity

For decades, various plants have been studied as sources of biologically active compounds. Compounds with anticancer and antimicrobial properties are the most frequently desired. Cruciferous plants, including Brussels sprouts, broccoli, and wasabi, have a special role in the research studies. Studies have shown that consumption of these plants reduce the risk of lung, breast, and prostate cancers. The high chemopreventive and anticancer potential of cruciferous plants results from the presence of a large amount of glucosinolates, which, under the influence of myrosinase, undergo an enzymatic transformation to biologically active isothiocyanates (ITCs). Natural isothiocyanates, such as benzyl isothiocyanate, phenethyl isothiocyanate, or the best-tested sulforaphane, possess anticancer activity at all stages of the carcinogenesis process, show antibacterial activity, and are used in organic synthesis. Methods of synthesis of sulforaphane, as well as its natural or synthetic bifunctional analogues with sulfinyl, sulfanyl, sulfonyl, phosphonate, phosphinate, phosphine oxide, carbonyl, ester, carboxamide, ether, or additional isothiocyanate functional groups, and with the unbranched alkyl chain containing 2-6 carbon atoms, are discussed in this review. The biological activity of these compounds are also reported. In the first section, glucosinolates, isothiocyanates, and mercapturic acids (their metabolites) are briefly characterized. Additionally, the most studied anticancer and antibacterial mechanisms of ITC actions are discussed.

Genetic Biomarkers of Metabolic Detoxification for Personalized Lifestyle Medicine

Metabolic detoxification (detox)—or biotransformation—is a physiological function that removes toxic substances from our body. Genetic variability and dietary factors may affect the function of detox enzymes, thus impacting the body’s sensitivity to toxic substances of endogenous and exogenous origin. From a genetic perspective, most of the current knowledge relies on observational studies in humans or experimental models in vivo and in vitro, with very limited proof of causality and clinical value. This review provides health practitioners with a list of single nucleotide polymorphisms (SNPs) located within genes involved in Phase I and Phase II detoxification reactions, for which evidence of clinical utility does exist. We have selected these SNPs based on their association with interindividual variability of detox metabolism in response to certain nutrients in the context of human clinical trials. In order to facilitate clinical interpretation and usage of these SNPs, we provide, for each of them, a strength of evidence score based on recent guidelines for genotype-based dietary advice. We also present the association of these SNPs with functional biomarkers of detox metabolism in a pragmatic clinical trial, the LIFEHOUSE study.

Angioprevention of Urologic Cancers by Plant-Derived Foods

The number of cancer cases worldwide keeps growing unstoppably, despite the undeniable advances achieved by basic research and clinical practice. Urologic tumors, including some as prevalent as prostate, bladder or kidney tumors, are no exceptions to this rule. Moreover, the fact that many of these tumors are detected in early stages lengthens the duration of their treatment, with a significant increase in health care costs. In this scenario, prevention offers the most cost-effective long-term strategy for the global control of these diseases. Although specialized diets are not the only way to decrease the chances to develop cancer, epidemiological evidence support the role of certain plant-derived foods in the prevention of urologic cancer. In many cases, these plants are rich in antiangiogenic phytochemicals, which could be responsible for their protective or angiopreventive properties. Angiogenesis inhibition may contribute to slow down the progression of the tumor at very different stages and, for this reason, angiopreventive strategies could be implemented at different levels of chemoprevention, depending on the targeted population. In this review, epidemiological evidence supporting the role of certain plant-derived foods in urologic cancer prevention are presented, with particular emphasis on their content in bioactive phytochemicals that could be used in the angioprevention of cancer.

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.

An Overview of Registered Clinical Trials on Glucosinolates and Human Health: The Current Situation

Epidemiological studies suggest a potential role of glucosinolates (GSLs) and isothiocyanates on human health. However, evidence from intervention studies, due to heterogeneity in features of study design, duration, participants, food or food components administered, and outcomes analyzed, is still insufficient. The current review aims to provide an overview of the trials on GSLs and GSL-rich foods registered over the last 20 years with the intention to summarize the main topics and results, but also the existing gaps that still need to be covered. Studies were collected by using ClinicalTrials.gov and the International Standard Randomized Controlled Trial Number (ISRCTN) registry. A total of 87 registered trials were identified with which most of them were performed by using extracts or pure compounds (n = 60) while few were conducted with GSL-rich foods (n = 27). In detail, sulforaphane was the most investigated compound, while broccoli was the most frequent food tested in the trials. The majority of the studies assessed the health effects of GSLs focusing on outcomes related to cancer and cognitive function, even if the current findings are not univocal. Emerging topics also included the study of GSLs and gut microbiota interaction and impact on skin health. Further attention was also drawn to the bioavailability of GSLs and/or derivatives from foods, extracts, and single compounds by also considering the contribution of the different genetic polymorphisms. In conclusion, although considerable efforts have been made to study GSLs and GSL-rich foods, further studies are necessary to provide evidence-based research and to corroborate the findings obtained. The interindividual response due to genetic polymorphisms should be further investigated in order to explore the contribution to the overall beneficial effect.

Sulforaphane: A Broccoli Bioactive Phytocompound with Cancer Preventive Potential

Simple Summary

As of the past decade, phytochemicals have become a major target of interest in cancer chemopreventive and chemotherapeutic research. Sulforaphane (SFN) is a metabolite of the phytochemical glucoraphanin, which is found in high abundance in cruciferous vegetables, such as broccoli, watercress, Brussels sprouts, and cabbage. In both distant and recent research, SFN has been shown to have a multitude of anticancer effects, increasing the need for a comprehensive review of the literature. In this review, we critically evaluate SFN as an anticancer agent and its mechanisms of action based on an impressive number of in vitro, in vivo, and clinical studies.

Abstract

There is substantial and promising evidence on the health benefits of consuming broccoli and other cruciferous vegetables. The most important compound in broccoli, glucoraphanin, is metabolized to SFN by the thioglucosidase enzyme myrosinase. SFN is the major mediator of the health benefits that have been recognized for broccoli consumption. SFN represents a phytochemical of high interest as it may be useful in preventing the occurrence and/or mitigating the progression of cancer. Although several prior publications provide an excellent overview of the effect of SFN in cancer, these reports represent narrative reviews that focused mainly on SFN’s source, biosynthesis, and mechanisms of action in modulating specific pathways involved in cancer without a comprehensive review of SFN’s role or value for prevention of various human malignancies. This review evaluates the most recent state of knowledge concerning SFN’s efficacy in preventing or reversing a variety of neoplasms. In this work, we have analyzed published reports based on in vitro, in vivo, and clinical studies to determine SFN’s potential as a chemopreventive agent. Furthermore, we have discussed the current limitations and challenges associated with SFN research and suggested future research directions before broccoli-derived products, especially SFN, can be used for human cancer prevention and intervention.

Sulforaphane as a potential remedy against cancer: Comprehensive mechanistic review

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

MicroRNA mediated therapeutic effects of natural agents in prostate cancer

BACKGROUND

Several natural products, extensively studied for their anticancer activities, have been found to play an efficient role in preventing prostate cancer (PCa). Recently many natural agents have been reported to modulate microRNAs (miRNAs), that are involved in cancer cell growth. The microRNAs are endogenous small noncoding ribonucleic acid molecules that regulate various biological processes through an elegant mechanism of post-transcriptional control of gene expression. Besides being involved in cancer initiation, progression, angiogenesis, inflammation, they have been reported to be responsible for chemoresistance, and radioresistance of tumors. The dysregulated miRNA expression has been associated with many cancers including PCa. Over the past several years, it has been found that natural agents are good regulators of miRNAs and have a role in PCa also. Understanding the molecular mechanisms involving miRNAs by natural agents could result in developing useful strategies to combat this deadly disease.

METHODS

In order to collect research articles, the PubMed search engine was used with keywords 'prostate cancer' and 'natural agents' and 2007 papers were retrieved, further refinement with keywords 'phytochemical' and 'prostate cancer' showed 503 papers. Data was collected from research articles, published from 2010 to 2021. From these, research articles showing miRNA-mediated mechanisms were selected.

RESULTS

In this review, we have summarized the information available on the modulation of miRNAs by natural agents, their derivatives, and various combinatorial strategies with chemo/radiation therapy for the mitigation of PCa.

CONCLUSIONS

Based on the current review of literature, it has been found that the use of natural agents is a novel approach for altering miRNA expression strongly associated with PCa development, recurrence and resistance.

Sulforaphane as a Promising Natural Molecule for Cancer Prevention and Treatment

Tumorigenicity-inhibiting compounds have been identified in our daily diet. For example, isothiocyanates (ITCs) found in cruciferous vegetables were reported to have potent cancer-prevention activities. The best characterized ITC is sulforaphane (SF). SF can simultaneously modulate multiple cellular targets involved in carcinogenesis, including (1) modulating carcinogen-metabolizing enzymes and blocking the action of mutagens; (2) inhibition of cell proliferation and induction of apoptosis; and (3) inhibition of neo-angiogenesis and metastasis. SF targets cancer stem cells through modulation of nuclear factor kappa B (NF-κB), Sonic hedgehog (SHH), epithelial-mesenchymal transition, and Wnt/β-catenin pathways. Conventional chemotherapy/SF combination was tested in several studies and resulted in favorable outcomes. With its favorable toxicological profile, SF is a promising agent in cancer prevention and/or therapy. In this article, we discuss the human metabolism of SF and its effects on cancer prevention, treatment, and targeting cancer stem cells, as well as providing a brief review of recent human clinical trials on SF.

Effects of in vivo treatment of mice with sulforaphane on repair of DNA pyridyloxylbutylation

The phytochemical sulforaphane (SF) has gained interest for its apparent association with reduced cancer risk and other cytoprotective properties, at least some of which are attributed to activation of the transcription factor Nrf2. Repair of bulky DNA adducts is important for mitigating carcinogenesis from exogenous DNA damaging agents, but it is unknown whether in vivo treatment with SF affects adduct repair. At 12 h following a single oral dose of 100 mg/kg SF, an almost doubling in activity for repair of pyridyloxobutylated DNA was observed in CD-1 mouse liver nuclear extracts, but not in lung extracts. This change at 12 h in repair activity was preceded by the induction of Nrf2-regulated genes but not accompanied by changes in levels of the specific nucleotide excision repair (NER) proteins XPC, XPA, XPB and p53 or in binding of hepatic XPC, XPA and XPB to damaged DNA. SF also did not significantly alter histone deacetylase activity as measured by acetylated histone H3 levels, or stimulate formation of γ-H2A.X, a marker of DNA damage. A significant reduction in oxidative DNA damage, as measured by 8-OHdG (a biomarker of oxidative DNA damage), was observed only in DNA from the lungs of SF-treated mice 3 h post-dosing. These results suggest that the ability of SF to increase bulky adduct repair activity is organ-selective and is consistent with activation of the Nrf2 signaling pathway.

Breast Cancer Prevention-Is there a Future for Sulforaphane and Its Analogs?

Breast cancer is the most prevalent type of cancer among women worldwide. There are several recommended methods of breast cancer prevention, including chemoprevention. There are several approved drugs used to prevent breast cancer occurrence or recurrence and metastasizing. There are also a number of new substances undergoing clinical trials and at the stage of initial study. Studies suggest that dietary factors play a crucial role in breast cancer etiology. Epidemiological studies indicate that in particular vegetables from the Brassicaceae family are a rich source of chemopreventive substances, with sulforaphane (SFN) being one of the most widely studied and characterized. This review discusses potential applicability of SFN in breast cancer chemoprevention. A comprehensive review of the literature on the impact of SFN on molecular signalling pathways in breast cancer and breast untransformed cells is presented. The presented results of in vitro and in vivo studies show that this molecule has a potential to act as a preventive molecule either to prevent disease development or recurrence and metastasizing, and as a compound protecting normal cells against the toxic effects of cytostatics. Finally, the still scanty attempts to develop an improved analog are also presented and discussed.

The Role of Lysosome-associated Membrane Protein 2 in Prostate Cancer Chemopreventive Mechanisms of Sulforaphane

Prostate cancer chemoprevention by sulforaphane, which is a metabolic by-product of glucoraphanin found in broccoli, in preclinical models is associated with induction of both apoptosis and autophagy. However, the molecular mechanism underlying sulforaphane-mediated autophagy, which is protective against apoptotic cell death by this phytochemical, is still poorly understood. This study demonstrates a role for lysosome-associated membrane protein 2 (LAMP2) in sulforaphane-mediated autophagy and apoptosis. Western blotting revealed dose-dependent induction of LAMP2 protein after treatment with sulforaphane as well as its naturally occurring analogs in PC-3 and 22Rv1 human prostate cancer cell lines that was confirmed by microscopy (sulforaphane). The mRNA level of LAMP2 was also increased upon treatment with sulforaphane in both cell lines. Sulforaphane-mediated increase in the level of autophagy marker microtubule-associated protein light-chain 3B was augmented by RNAi of LAMP2 in PC-3 and 22Rv1 cells. Apoptosis induction by sulforaphane treatment was also increased significantly by knockdown of the LAMP2 protein in PC-3 and 22Rv1 cells. Augmentation of sulforaphane-mediated apoptosis by RNAi of LAMP2 was accompanied by induction and activation of proapoptotic protein Bak. Oral administration of sulforaphane to TRAMP mice also resulted in induction of LAMP2 protein expression. Targeted microarray in sulforaphane-treated PC-3 cells revealed induction of many autophagy-related genes (e.g., HSP90AA1, NRF2, etc) and their expression positively correlated with that of LAMP2 in prostate cancer The Cancer Genome Atlas. In conclusion, this study reveals that induction of LAMP2 by sulforaphane inhibits its ability to induce apoptotic cell death at least in human prostate cancer cells.

Can Nrf2 Modulate the Development of Intestinal Fibrosis and Cancer in Inflammatory Bowel Disease?

One of the main mechanisms carried out by the cells to counteract several forms of stress is the activation of the nuclear factor erythroid 2-related factor (Nrf2) signaling. Nrf2 signaling controls the expression of many genes through the binding of a specific cis-acting element known as the antioxidant response element (ARE). Activation of Nrf2/ARE signaling can mitigate several pathologic mechanisms associated with an autoimmune response, digestive and metabolic disorders, as well as respiratory, cardiovascular, and neurodegenerative diseases. Indeed, several studies have demonstrated that Nrf2 pathway plays a key role in inflammation and in cancer development in many organs, including the intestine. Nrf2 appears to be involved in inflammatory bowel disease (IBD), an immune-mediated chronic and disabling disease, with a high risk of developing intestinal fibrotic strictures and cancer. Currently, drugs able to increase cytoprotective Nrf2 function are in clinical trials or already being used in clinical practice to reduce the progression of some degenerative conditions. The role of Nrf2 in cancer development and progression is controversial, and drugs able to inhibit abnormal levels of Nrf2 are also under investigation. The goal of this review is to analyze and discuss Nrf2-dependent signals in the initiation and progression of intestinal fibrosis and cancers occurring in IBD.

The Glucosinolates: A Sulphur Glucoside Family of Mustard Anti-Tumour and Antimicrobial Phytochemicals of Potential Therapeutic Application

This study reviewed aspects of the biology of two members of the glucosinolate family, namely sinigrin and glucoraphanin and their anti-tumour and antimicrobial properties. Sinigrin and glucoraphanin are converted by the β-sulphoglucosidase myrosinase or the gut microbiota into their bioactive forms, allyl isothiocyanate (AITC) and sulphoraphanin (SFN) which constitute part of a sophisticated defence system plants developed over several hundred million years of evolution to protect them from parasitic attack from aphids, ticks, bacteria or nematodes. Delivery of these components from consumption of cruciferous vegetables rich in the glucosinolates also delivers many other members of the glucosinolate family so the dietary AITCs and SFN do not act in isolation. In vitro experiments with purified AITC and SFN have demonstrated their therapeutic utility as antimicrobials against a range of clinically important bacteria and fungi. AITC and SFN are as potent as Vancomycin in the treatment of bacteria listed by the World Health Organisation as antibiotic-resistant “priority pathogens” and also act as anti-cancer agents through the induction of phase II antioxidant enzymes which inactivate potential carcinogens. Glucosinolates may be useful in the treatment of biofilms formed on medical implants and catheters by problematic pathogenic bacteria such as Pseudomonas aeruginosa and Staphylococcus aureus and are potent antimicrobials against a range of clinically important bacteria and fungi. The glucosinolates have also been applied in the prevention of bacterial and fungal spoilage of food products in advanced atmospheric packaging technology which improves the shelf-life of these products.

Epidemiology of Prostate Cancer

Prostate cancer is the second most frequent cancer diagnosis made in men and the fifth leading cause of death worldwide. Prostate cancer may be asymptomatic at the early stage and often has an indolent course that may require only active surveillance. Based on GLOBOCAN 2018 estimates, 1,276,106 new cases of prostate cancer were reported worldwide in 2018, with higher prevalence in the developed countries. Differences in the incidence rates worldwide reflect differences in the use of diagnostic testing. Prostate cancer incidence and mortality rates are strongly related to the age with the highest incidence being seen in elderly men (> 65 years of age). African-American men have the highest incidence rates and more aggressive type of prostate cancer compared to White men. There is no evidence yet on how to prevent prostate cancer; however, it is possible to lower the risk by limiting high-fat foods, increasing the intake of vegetables and fruits and performing more exercise. Screening is highly recommended at age 45 for men with familial history and African-American men. Up-to-date statistics on prostate cancer occurrence and outcomes along with a better understanding of the etiology and causative risk factors are essential for the primary prevention of this disease.

Transcriptional changes in prostate of men on active surveillance after a 12-mo glucoraphanin-rich broccoli intervention-results from the Effect of Sulforaphane on prostate CAncer PrEvention (ESCAPE) randomized controlled trial

BACKGROUND

Epidemiological evidence suggests that consumption of cruciferous vegetables is associated with reduced risk of prostate cancer progression, largely attributed to the biological activity of glucosinolate degradation products, such as sulforaphane derived from glucoraphanin. Because there are few therapeutic interventions for men on active surveillance for prostate cancer to reduce the risk of cancer progression, dietary approaches are an appealing option for patients.

OBJECTIVE

We evaluated whether consumption of a glucoraphanin-rich broccoli soup for 1 y leads to changes in gene expression in prostate tissue of men with localized prostate cancer.

METHODS

Forty-nine men on active surveillance completed a 3-arm parallel randomized double-blinded intervention study for 12 mo and underwent transperineal template biopsy procedures and dietary assessment at the start and end of the study. Patients received a weekly 300 mL portion of soup made from a standard broccoli (control) or from 1 of 2 experimental broccoli genotypes with enhanced concentrations of glucoraphanin, delivering 3 and 7 times that of the control, respectively. Gene expression in tissues from each patient obtained before and after the dietary intervention was quantified by RNA sequencing followed by gene set enrichment analyses.

RESULTS

In the control arm, there were several hundred changes in gene expression in nonneoplastic tissue during the 12 mo. These were associated with an increase in expression of potentially oncogenic pathways including inflammation processes and epithelial-mesenchymal transition. Changes in gene expression and associated oncogenic pathways were attenuated in men on the glucoraphanin-rich broccoli soup in a dose-dependent manner. Although the study was not powered to assess clinical progression, an inverse association between consumption of cruciferous vegetables and cancer progression was observed.

CONCLUSION

Consuming glucoraphanin-rich broccoli soup affected gene expression in the prostate of men on active surveillance, consistent with a reduction in the risk of cancer progression. This trial was registered at clinicaltrials.gov as NCT01950143.

Integrated Utilization of Red Radish for the Efficient Production of High-Purity Procyanidin Dimers

Red radish was extracted by methanol to obtain crude radish procyanidin extracts. The purity of procyanidin (PP) and procyanidin dimers (PD) of crude radish procyanidin extracts under different ratios of methanol to radish was optimized to achieve the best extraction performance. Then the crude radish procyanidin extracts was, respectively, processed six macroporous resins separation to separate radish procyanidin oligomers (RPO) and polymers (RPP). Depolymerization of radish procyanidin polymers (RPP) into oligomers was then conducted. N-Acetylneuraminate lyase (NAL) was first used as the enzyme to depolymerize RPP. The depolymerization yield (DY) under different depolymerized conditions was also investigated. Results showed the DY of RPP would achieve 53.24 ± 0.35% at the best conditions. Then the high-purity procyanidin dimers was prepared by depolymerized procyanidin oligomers and PRO. Additionally, the chemical structure of the preparative radish procyanidin dimers was elucidated by high-resolution mass spectrometry and one- and two-dimensional NMR.

Effects of long-term consumption of broccoli sprouts on inflammatory markers in overweight subjects

BACKGROUND & AIMS

Broccoli sprouts represent an interesting choice of healthy food product as they are rich in glucosinolates and their cognate bioactive metabolites, isothiocyanates able to counteract the negative effects of diverse pathologies. As obesity is linked to an inflammatory component, the aim of the study was to evaluate the anti-inflammatory action of broccoli sprouts in overweight adult subjects.

METHODS

An in vivo controlled study was performed in 40 healthy overweight subjects (ClinicalTrials.gov ID NCT 03390855). Treatment phase consisted on the consumption of broccoli sprouts (30 g/day) during 10 weeks and the follow-up phase of 10 weeks of normal diet without consumption of these broccoli sprouts. Anthropometric parameters as body fat mass, body weight, and BMI were determined. Inflammation status was assessed by measuring levels of TNF-α, IL-6, IL-1β and C-reactive protein.

RESULTS

IL-6 levels significantly decreased (mean values from 4.76 pg/mL to 2.11 pg/mL with 70 days of broccoli consumption, p < 0.001) and during control phase the inflammatory levels were maintained at low grade (mean values from 1.20 pg/mL to 2.66 pg/mL, p < 0.001). C-reactive protein significantly decreased as well.

CONCLUSIONS

This study represents an advance in intervention studies as the broccoli sprouts were included in a daily dietary pattern in quantities that reflect a real consumption. Further studies are necessary to elucidate the role of this healthy rich and nutritious food product, but these promising results support the current evidence on the healthy properties of Brassica varieties.

Design, Synthesis, and Evaluation of ω-(Isothiocyanato)alkylphosphinates and Phosphine Oxides as Antiproliferative Agents

A series of 21 novel, structurally diverse ω-(isothiocyanato)alkylphosphinates and phosphine oxides (ITCs) were designed and synthesized in moderate to good yields. The synthesized compounds were evaluated for in vitro antiproliferative activity using LoVo and LoVo/DX cancer cell lines. The biological activity of the synthesized compounds was higher than that of natural isothiocyanates such as benzyl isothiocyanate or sulforaphane. The antiproliferative activity of selected ITCs was also tested on selected cancer cell lines: A549, MESSA and MESSA/DX-5, HL60 and HL60MX2, BALB/3T3, and 4T1. These compounds were assessed for their mechanism of action as inducers of cell-cycle arrest and apoptosis. Ethyl (6-isothiocyanatohexyl)(phenyl)phosphinate (71) was tested in vivo on the 4T1 cell line and demonstrated moderate antitumor activity, similar to that benzyl isothiocyanate and cyclophosphamide.

Nrf2 targeting by sulforaphane: A potential therapy for cancer treatment

In the past decades, extensive studies have reported the potential chemopreventive activity of sulforaphane, an isothiocyanate derived from glucoraphanin, occurring in large amounts in Brassica genus plants. Sulforaphane was found to be active against several forms of cancer. A growing body of data shows that sulforaphane acts against cancer at different levels, from development to progression, through pleiotropic effects. In this review, we discuss the available experimental and clinical data on the potential therapeutic role of sulforaphane against cancer. Its effects range from the protection of cells from DNA damage to the modulation of the cell cycle via pro-apoptotic, anti-angiogenesis and anti-metastasis activities. At molecular level, sulforaphane modulates cellular homeostasis via the activation of the transcription factor Nrf2. Although data from clinical studies are limited, sulforaphane remains a good candidate in the adjuvant therapy based on natural molecules against several types of cancer.

Metabolic Profiling and Antioxidant Assay of Metabolites from Three Radish Cultivars (Raphanus sativus)

A total of 13 anthocyanins and 33 metabolites; including organic acids, phenolic acids, amino acids, organic compounds, sugar acids, sugar alcohols, and sugars, were profiled in three radish cultivars by using high-performance liquid chromatography (HPLC) and gas chromatography time-of-flight mass spectrometry (GC-TOFMS)-based metabolite profiling. Total phenolics and flavonoids and their in vitro antioxidant activities were assessed. Pelargonidins were found to be the major anthocyanin in the cultivars studied. The cultivar Man Tang Hong showed the highest level of anthocyanins (1.89 ± 0.07 mg/g), phenolics (0.0664 ± 0.0033 mg/g) and flavonoids (0.0096 ± 0.0004 mg/g). Here; the variation of secondary metabolites in the radishes is described, as well as their association with primary metabolites. The low-molecular-weight hydrophilic metabolite profiles were subjected to principal component analysis (PCA), hierarchical clustering analysis (HCA), Pearson’s correlation analysis. PCA fully distinguished the three radish cultivars tested. The polar metabolites were strongly correlated between metabolites that participate in the TCA cycle. The chemometrics results revealed that TCA cycle intermediates and free phenolic acids as well as anthocyanins were higher in the cultivar Man Tang Hong than in the others. Furthermore; superoxide radical scavenging activities and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging were investigated to elucidate the antioxidant activity of secondary metabolites in the cultivars. Man Tang Hong showed the highest superoxide radical scavenging activity (68.87%) at 1000 μg/mL, and DPPH activity (20.78%), followed by Seo Ho and then Hong Feng No. 1. The results demonstrate that GC-TOFMS-based metabolite profiling, integrated with chemometrics, is an applicable method for distinguishing phenotypic variation and determining biochemical reactions connecting primary and secondary metabolism. Therefore; this study might provide information on the relationship between primary and secondary metabolites and a synergistic antioxidant ability derived from the secondary metabolites in the radish cultivars.

GSTT1 Null Genotype Significantly Increases the Susceptibility to Urinary System Cancer: Evidences from 63,876 Subjects

GSTT1 gene plays an important role in detoxification and clearance of reactive oxygen species(ROS). A null variant in this gene has been demonstrated to confer cancer susceptibility. Although many studies have demonstrated the association between GSTT1 null polymorphism and urinary system cancer susceptibility, several publications reported opposite conclusions. For better understanding the effects of this polymorphism on the risk of urinary system cancer, a updated meta-analysis was performed with a total of 26,666 cases and 37,210 controls extracted from 117 studies, by following the latest meta-analysis guidelines (PRISMA). The results suggested that the GSTT1 null genotype was significantly associated with an increased risk of urinary system cancer (OR=1.13, 95%CI=1.05-1.22). Furthermore, stratified analyses by the type of cancer, ethnicity, source of control and quality score presented a significantly increased risk associated with GSTT1 null genotype in bladder and prostate cancer subgroup, Caucasians and Indians subgroup, population-based(PB) subgroup, medium quality and low quality subgroup. Overall, our meta-analysis suggested that GSTT1 null genotype is a potential cancer susceptibility variant. Well-designed and large-cohort studies are needed to confirm the association between GSTT1 null genotype and urinary system cancer risk.

GSTM1 Gene Polymorphism is Implicated in Increased Susceptibility to Prostate Cancer in Caucasians and Asians

Published reports on the relationship between GSTM1 gene polymorphisms and prostate cancer risk are heterogeneous in their conclusions, and the significance of these polymorphisms is still debated. This meta-analysis was performed to attempt to combine comparable studies, thereby increasing sample size and statistical significance in order to obtain a better evaluation of the association between GSTM1 polymorphisms and prostate cancer risk. The association investigations were identified from PubMed, Cochrane Library, and China Biological Medicine Database on March 1, 2014. Forty-three reports were recruited into this meta-analysis that contained data from 6741 patients and 9053 controls. There was a marked association between the GSTM1 null genotype and prostate cancer risk in the overall population (odds ratio = 1.39, 95% confidence interval: 1.21-1.60, P <00001), caucasians (odds ratio = 1.48, 95% confidence interval: 1.23-1.79, P <0001) and Asians (odds ratio = 1.62, 95% confidence interval: 1.16-2.27, P = .005). However, the GSTM1 null genotype was not associated with prostate cancer risk in Africans (odds ratio = 0.77, 95% confidence interval: 0.53-1.13, P = 0.19) and African Americans (odds ratio = 1.00, 95% confidence interval: 0.69-1.45, P = 0.99). In conclusion, GSTM1 null genotype was a risk factor to predict the prostate cancer risk in the overall population, Caucasians, and Asians. Although compelling, limitations inherent to meta-analysis, study design of the individual studies, and most importantly, possible gene-gene and gene-environment interactions, as well as the potential involvement of glutathione S-transferases in multiple cellular processes make drawing definite conclusions difficult.

The synergistic effect between the Mediterranean diet and GSTP1 or NAT2 SNPs decreases breast cancer risk in Greek-Cypriot women

PURPOSE

Xenobiotic metabolism is related to the interplay between diet and breast cancer (BC) risk. This involves detoxification enzymes, which are polymorphic and metabolise various dietary metabolites. An important characteristic of this pathway is that chemoprotective micronutrients can act not only as substrates but also as inducers for these enzymes. We investigated whether functional GSTP1 (p.Ile105Val-rs1695), NAT2 (590G>A-rs1799930) SNPs and GSTM1 and GSTT1 deletion polymorphisms could modulate the effect of the Mediterranean diet (MD) on BC risk, in Greek-Cypriot women.

METHODS

Genotyping was performed on women from the MASTOS case-control study of BC in Cyprus. A 32-item food-frequency questionnaire was used to obtain dietary intake information. A dietary pattern, which closely resembles the MD (high loadings of vegetables, fruit, legumes and fish), was previously derived with principal component analysis and was used as our dietary variable.

RESULTS

GSTT1 null genotype increased BC risk compared with the homozygous non-null GSTT1 genotype (OR 1.21, 95 % CI 1.01-1.45). Increasing adherence to the MD reduced BC risk in women with at least one GSTP1 Ile allele (OR for Ile/Ile = 0.84, 95 % CI 0.74-0.95, for Ile/Val = 0.73, 95 % CI 0.62-0.85) or one NAT2 590G allele (OR for 590 GG = 0.73, 95 % CI 0.63-0.83, for 590 GA = 0.81, 95 % CI 0.70-0.94). p interaction values were not, however, statistically significant.

CONCLUSION

The homozygous null GSTT1 genotype could be a risk allele for BC among Greek-Cypriot women. The anticarcinogenic effects of the high adherence to MD against BC risk could also be further enhanced when combined with the wild-type alleles of the detoxification GSTP1 or NAT2 SNPs.

Association between Dietary Patterns and Atopic Dermatitis in Relation to GSTM1 and GSTT1 Polymorphisms in Young Children

Previous research suggests the association of glutathione S-transferase (GST) gene polymorphisms or diet, but no interactions between these factors in atopic dermatitis (AD). We conducted a community-based case-control study including 194 AD and 244 matched non-AD preschoolers. Glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) present/null genotypes were evaluated uisng a multiplex PCR method. We measured dietary intakes by a validated food frequency questionnaire and constructed three dietary patterns such as “traditional healthy”, “animal foods”, and “sweets” diets. In stratified analyses by GST genotypes, the “traditional healthy” diet and reduced AD showed association only in the GSTM1-present group (odd ratio (OR) 0.31, 95% confidence interval (CI) 0.13–0.75). A similar pattern of the association existed in the combined GSTM1/T1 genotype that indicated the inverse association between the “traditional healthy” diet and AD in the double GSTM1/T1-present genotype group (OR 0.24, 95% CI 0.06–0.93). Results from the multiplicative test analyses showed that the “traditional healthy” diet on reduced AD was significant or borderline significant in the GSTM1-present group (OR 0.71, 95% CI 0.54–0.92 vs. GSTM1-null group) or the GSTM1/T1 double present group (OR 0.63, 95% CI 0.39–1.03 vs. GSTM1/T1 double null group). These findings demonstrate that the present type of GSTM1 may increase susceptibility to the potential effect of the “traditional healthy” diet on AD.

Dietary Sulforaphane in Cancer Chemoprevention: The Role of Epigenetic Regulation and HDAC Inhibition

SIGNIFICANCE

Sulforaphane, produced by the hydrolytic conversion of glucoraphanin after ingestion of cruciferous vegetables, particularly broccoli and broccoli sprouts, has been extensively studied due to its apparent health-promoting properties in disease and limited toxicity in normal tissue. Recent Studies: Recent identification of a sub-population of tumor cells with stem cell-like self-renewal capacity that may be responsible for relapse, metastasis, and resistance, as a potential target of the dietary compound, may be an important aspect of sulforaphane chemoprevention. Evidence also suggests that sulforaphane may target the epigenetic alterations observed in specific cancers, reversing aberrant changes in gene transcription through mechanisms of histone deacetylase inhibition, global demethylation, and microRNA modulation.

CRITICAL ISSUES

In this review, we discuss the biochemical and biological properties of sulforaphane with a particular emphasis on the anticancer properties of the dietary compound. Sulforaphane possesses the capacity to intervene in multistage carcinogenesis through the modulation and/or regulation of important cellular mechanisms. The inhibition of phase I enzymes that are responsible for the activation of pro-carcinogens, and the induction of phase II enzymes that are critical in mutagen elimination are well-characterized chemopreventive properties. Furthermore, sulforaphane mediates a number of anticancer pathways, including the activation of apoptosis, induction of cell cycle arrest, and inhibition of NFκB.

FUTURE DIRECTIONS

Further characterization of the chemopreventive properties of sulforaphane and its capacity to be selectively toxic to malignant cells are warranted to potentially establish the clinical utility of the dietary compound as an anti-cancer compound alone, and in combination with clinically relevant therapeutic and management strategies.

Interaction of sulforaphane with DNA and RNA

Sulforaphane (SFN) is an isothiocyanate found in cruciferous vegetables with anti-inflammatory, anti-oxidant and anti-cancer activities. However, the antioxidant and anticancer mechanism of sulforaphane is not well understood. In the present research, we reported binding modes, binding constants and stability of SFN-DNA and -RNA complexes by Fourier transform infrared (FTIR) and UV-Visible spectroscopic methods. Spectroscopic evidence showed DNA intercalation with some degree of groove binding. SFN binds minor and major grooves of DNA and backbone phosphate (PO2), while RNA binding is through G, U, A bases with some degree of SFN-phosphate (PO2) interaction. Overall binding constants were estimated to be K(SFN-DNA)=3.01 (± 0.035)×10(4) M(-1) and K(SFN-RNA)= 6.63 (±0.042)×10(3) M(-1). At high SFN concentration (SFN/RNA = 1/1), DNA conformation changed from B to A occurred, while RNA remained in A-family structure.

Disintegration of microtubules in Arabidopsis thaliana and bladder cancer cells by isothiocyanates

Isothiocyanates (ITCs) from biodegradation of glucosinolates comprise a group of electrophiles associated with growth-inhibitory effects in plant- and mammalian cells. The underlying modes of action of this feature are not fully understood. Clarifying this has involved mammalian cancer cells due to ITCs' chemopreventive potential. The binding of ITCs to tubulins has been reported as a mechanism by which ITCs induce cell cycle arrest and apoptosis. In the present study we demonstrate that ITCs disrupt microtubules in Arabidopsis thaliana contributing to the observed inhibited growth phenotype. We also confirmed this in rat bladder cancer cells (AY-27) suggesting that cells from plant and animals share mechanisms by which ITCs affect growth. Exposure of A. thaliana to vapor-phase of allyl ITC (AITC) inhibited growth and induced a concurrent bleaching of leaves in a dose-dependent manner. Transcriptional analysis was used to show an upregulation of heat shock-genes upon AITC-treatment. Transgenic A. thaliana expressing GFP-marked α-tubulin was employed to show a time- and dose-dependent disintegration of microtubules by AITC. Treatment of AY-27 with ITCs resulted in a time- and dose-dependent decrease of cell proliferation and G2/M-arrest. AY-27 transiently transfected to express GFP-tagged α-tubulin were treated with ITCs resulting in a loss of microtubular filaments and the subsequent formation of apoptotic bodies. In conclusion, our data demonstrate an ITC-induced mechanism leading to growth inhibition in A. thaliana and rat bladder cancer cells, and expose clues to the mechanisms underlying the physiological role of glucosinolates in vivo.

A phase II study of sulforaphane-rich broccoli sprout extracts in men with recurrent prostate cancer

INTRODUCTION

Diets high in cruciferous vegetables are associated with lower risk of incidence of prostate cancer, including aggressive forms of this disease. Human intervention studies with cruciferous vegetable-rich diets also demonstrate modulation of gene expression in important pathways in prostate cells.

PURPOSE

Sulforaphane is a constituent of these foods postulated to harbor the anti-neoplastic activity based on multiple tumor models. Our own work demonstrates that sulforaphane inhibits AR signaling in prostate cancer cells. Here, we report results from the first clinical trial of sulforaphane-rich extracts in men with prostate cancer.

METHODS

We treated 20 patients who had recurrent prostate cancer with 200 μmoles/day of sulforaphane-rich extracts for a maximum period of 20 weeks and determined the proportion of patients with ≥50% PSA declines, the primary endpoint. Only one subject experienced a ≥50% PSA decline. Thus, the primary endpoint was not achieved. Seven patients experienced smaller PSA declines (<50%). There was also a significant lengthening of the on-treatment PSA doubling time (PSADT) compared with the pre-treatment PSADT [6.1 months pre-treatment vs. 9.6 months on-treatment (p = 0.044)]. Finally, treatment with sulforaphane-rich extracts was safe with no Grade 3 adverse events.

CONCLUSIONS

Treatment with 200 μmoles/day of sulforaphane-rich extracts did not lead to ≥50% PSA declines in the majority of patients. However, because of the safety of treatment and the effects on PSADT modulation, further studies, including those with higher doses, may be warranted to clarify the role of sulforaphane as a prevention agent or treatment agent.

Sulforaphane-induced autophagy flux prevents prion protein-mediated neurotoxicity through AMPK pathway

Prion diseases are neurodegenerative and infectious disorders that involve accumulation of misfolded scrapie prion protein, and which are characterized by spongiform degeneration. Autophagy, a major homeostatic process responsible for the degradation of cytoplasmic components, has garnered attention as the potential target for neurodegenerative diseases such as prion disease. We focused on protective effects of sulforaphane found in cruciferous vegetables on prion-mediated neurotoxicity and the mechanism of sulforaphane related to autophagy. In human neuroblastoma cells, sulforaphane protected prion protein (PrP) (106-126)-mediated neurotoxicity and increased autophagy flux marker microtubule-associated protein 1 light chain 3-II protein levels, following a decrease of p62 protein level. Pharmacological and genetical inhibition of autophagy by 3MA, wortmannin and knockdown of autophagy-related 5 (ATG5) led to block the effect of sulforaphane against PrP (106-126)-induced neurotoxicity. Furthermore we demonstrated that both sulforaphane-induced autophagy and protective effect of sulforaphane against PrP (106-126)-induced neurotoxicity are dependent on the AMP-activated protein kinase (AMPK) signaling. The present results indicated that sulforaphane of cruciferous vegetables enhanced autophagy flux led to the protection effects against prion-mediated neurotoxicity, which was regulated by AMPK signaling pathways in human neuron cells. Our data also suggest that sulforaphane has a potential value as a therapeutic tool in neurodegenerative disease including prion diseases.

Antileukemic activity of sulforaphane in primary blasts from patients affected by myelo- and lympho-proliferative disorders and in hypoxic conditions

Sulforaphane is a dietary isothiocyanate found in cruciferous vegetables showing antileukemic activity. With the purpose of extending the potential clinical impact of sulforaphane in the oncological field, we investigated the antileukemic effect of sulforaphane on blasts from patients affected by different types of leukemia and, taking into account the intrinsically hypoxic nature of bone marrow, on a leukemia cell line (REH) maintained in hypoxic conditions. In particular, we tested sulforaphane on patients with chronic lymphocytic leukemia, acute myeloid leukemia, T-cell acute lymphoblastic leukemia, B-cell acute lymphoblastic leukemia, and blastic NK cell leukemia. Sulforaphane caused a dose-dependent induction of apoptosis in blasts from patients diagnosed with acute lymphoblastic or myeloid leukemia. Moreover, it was able to cause apoptosis and to inhibit proliferation in hypoxic conditions on REH cells. As to its cytotoxic mechanism, we found that sulforaphane creates an oxidative cellular environment that induces DNA damage and Bax and p53 gene activation, which in turn helps trigger apoptosis. On the whole, our results raise hopes that sulforaphane might set the stage for a novel therapeutic principle complementing our growing armature against malignancies and advocate the exploration of sulforaphane in a broader population of leukemic patients.

GSTT1 polymorphism and the risk of developing prostate cancer

A possible association between glutathione S-transferase theta 1 gene (GSTT1) polymorphism and the risk of developing prostate cancer is currently hotly debated, but evidence from various epidemiologic studies remains unclear. This investigation was performed to assess whether an association between GSTT1 polymorphism and prostate cancer risk exists by using meta-analysis to combine comparable studies, thereby increasing sample size and statistical significance, as well as to identify patterns in various studies. The association reports were identified from the PubMed database and the Cochrane Library on March 1, 2013, and data from eligible studies (from 1999-2012) were synthesized. Thirty-eight reports were included in this meta-analysis on the association of the null genotype of GSTT1 with prostate cancer risk. No solid association between the GSTT1 null genotype and prostate cancer risk could be established for the overall population (odds ratio = 1.11, 95% confidence interval: 0.97, 1.27; P = 0.13). However, the GSTT1 null genotype was distinctly associated with prostate cancer risk in Caucasians (odds ratio = 1.24, 95% confidence interval: 1.03, 1.48, P = 0.02). In conclusion, the GSTT1 null genotype is associated with prostate cancer risk in Caucasians, but not in the overall population.