Pre- and Post-harvest Factors Affecting Glucosinolate Content in Broccoli

Owing to several presumed health-promoting biological activities, increased attention is being given to natural plant chemicals, especially those frequently entering the human diet. Glucosinolates (GLs) are the main bioactive compounds found in broccoli (Brassica oleracea L. var. italica Plenck). Their regular dietary assumption has been correlated with reduced risk of various types of neoplasms (lung, colon, pancreatic, breast, bladder, and prostate cancers), some degenerative diseases, such as Alzheimer's, and decreased incidence of cardiovascular pathologies. GL's synthesis pathway and regulation mechanism have been elucidated mainly in Arabidopsis. However, nearly 56 putative genes have been identified as involved in the B. oleracea GL pathway. It is widely recognized that there are several pre-harvest (genotype, growing environment, cultural practices, ripening stage, etc.) and post-harvest (harvesting, post-harvest treatments, packaging, storage, etc.) factors that affect GL synthesis, profiles, and levels in broccoli. Understanding how these factors act and interact in driving GL accumulation in the edible parts is essential for developing new broccoli cultivars with improved health-promoting bioactivity. In this regard, any systematic and comprehensive review outlining the effects of pre- and post-harvest factors on the accumulation of GLs in broccoli is not yet available. Thus, the goal of this paper is to fill this gap by giving a synoptic overview of the most relevant and recent literature. The existence of substantial cultivar-to-cultivar variation in GL content in response to pre-harvest factors and post-harvest manipulations has been highlighted and discussed. The paper also stresses the need for adapting particular pre- and post-harvest procedures for each particular genotype in order to maintain nutritious, fresh-like quality throughout the broccoli value chain.

Co-administration of sulforaphane and doxorubicin attenuates breast cancer growth by preventing the accumulation of myeloid-derived suppressor cells

Sulforaphane (SFN) is a compound derived from cruciferous plants shown to be effective in cancer prevention and suppression. Myeloid-derived suppressor cells (MDSCs) are known to inhibit anti-tumor immunity; however, whether SFN regulates the anti-tumor activity of MDSCs in breast cancer is still unknown. In the current study, we found that SFN blocked prostaglandin E2 (PGE2) synthesis in parental and doxorubicin (DOX)-resistant breast cancer 4T1 cell lines by activating NF-E2-related factor 2 (Nrf2). Nrf2-mediated reduction of PGE2 was dependent on the enhanced expression of heme oxygenase 1 (HO-1) and glutamate-cysteine ligase (GCLC), and decreased COX-2 expression in breast cancer cells. Moreover, our study further revealed that reduced PGE2 secretion from SFN-treated 4T1 cells triggered MDSCs to switch to an immunogenic phenotype, enhancing the anti-tumor activities of CD8⁺ T cells. Co-administration of SFN and DOX was more efficacious for the treatment of breast cancer in a mouse model than either agent alone, as evidenced by the significant decrease in tumor volume, MDSC expansion, and increase in cytotoxic CD8⁺ T cells. Taken together, our data indicate that SFN reverses the immunosuppressive microenvironment and is a potent adjuvant chemotherapeutic candidate in breast cancer.

Mechanisms of diabetic cardiomyopathy and potential therapeutic strategies: preclinical and clinical evidence

The pathogenesis and clinical features of diabetic cardiomyopathy have been well-studied in the past decade, but effective approaches to prevent and treat this disease are limited. Diabetic cardiomyopathy occurs as a result of the dysregulated glucose and lipid metabolism associated with diabetes mellitus, which leads to increased oxidative stress and the activation of multiple inflammatory pathways that mediate cellular and extracellular injury, pathological cardiac remodelling, and diastolic and systolic dysfunction. Preclinical studies in animal models of diabetes have identified multiple intracellular pathways involved in the pathogenesis of diabetic cardiomyopathy and potential cardioprotective strategies to prevent and treat the disease, including antifibrotic agents, anti-inflammatory agents and antioxidants. Some of these interventions have been tested in clinical trials and have shown favourable initial results. In this Review, we discuss the mechanisms underlying the development of diabetic cardiomyopathy and heart failure in type 1 and type 2 diabetes mellitus, and we summarize the evidence from preclinical and clinical studies that might provide guidance for the development of targeted strategies. We also highlight some of the novel pharmacological therapeutic strategies for the treatment and prevention of diabetic cardiomyopathy.

Sulforaphane Inhibits MGO-AGE-Mediated Neuroinflammation by Suppressing NF-κB, MAPK, and AGE-RAGE Signaling Pathways in Microglial Cells

Advanced glycation end products (AGEs) are produced through the binding of glycated protein or lipid with sugar, and they are known to be involved in the pathogenesis of both age-dependent and independent neurological complications. Among dicarbonyl compounds, methylglyoxal (MGO), which is produced from glucose breakdown, is a key precursor of AGE formation and neurotoxicity. Several studies have shown the toxic effects of bovine serum albumin (BSA)-AGE (prepared with glucose, sucrose or fructose) both in in vitro and in vivo. In fact, MGO-derived AGEs (MGO-AGEs) are highly toxic to neurons and other cells of the central nervous system. Therefore, we aimed to investigate the role of MGO-AGEs in microglial activation, a key inflammatory event, or secondary brain damage in neuroinflammatory diseases. Interestingly, we found that sulforaphane (SFN) as a potential candidate to downregulate neuroinflammation induced by MGO-AGEs in BV2 microglial cells. SFN not only inhibited the formation of MGO-AGEs, but it did not show breaking activity on the MGO-mediated AGEs cross-links with protein, indicating that SFN could potentially trap MGO or inhibit toxic AGE damage. In addition, SFN significantly attenuated the production of neuroinflammatory mediators induced by MGO-AGEs in BV2 microglial cells. SFN also lowered the expression levels of AGE receptor (RAGE) in microglial cells, suggesting that SFN could downregulate MGO-AGE-mediated neurotoxicity at the receptor activation level. Altogether, our current study revealed that SFN might show neuropharmacological potential for downregulating MGO-AGEs-mediated neuronal complications thorough attenuating AGE formation and neuroinflammatory responses induced by MGO-AGEs in vitro.

A Metabolic Pathway for Activation of Dietary Glucosinolates by a Human Gut Symbiont

Consumption of glucosinolates, pro-drug-like metabolites abundant in Brassica vegetables, has been associated with decreased risk of certain cancers. Gut microbiota have the ability to metabolize glucosinolates, generating chemopreventive isothiocyanates. Here, we identify a genetic and biochemical basis for activation of glucosinolates to isothiocyanates by Bacteroides thetaiotaomicron, a prominent gut commensal species. Using a genome-wide transposon insertion screen, we identified an operon required for glucosinolate metabolism in B. thetaiotaomicron. Expression of BT2159-BT2156 in a non-metabolizing relative, Bacteroides fragilis, resulted in gain of glucosinolate metabolism. We show that isothiocyanate formation requires the action of BT2158 and either BT2156 or BT2157 in vitro. Monocolonization of mice with mutant BtΔ2157 showed reduced isothiocyanate production in the gastrointestinal tract. These data provide insight into the mechanisms by which a common gut bacterium processes an important dietary nutrient.

Current Landscape of NRF2 Biomarkers in Clinical Trials

The transcription factor NF-E2 p45-related factor 2 (NRF2; encoded by NFE2L2) plays a critical role in the maintenance of cellular redox and metabolic homeostasis, as well as the regulation of inflammation and cellular detoxication pathways. The contribution of the NRF2 pathway to organismal homeostasis is seen in many studies using cell lines and animal models, raising intense attention towards targeting its clinical promise. Over the last three decades, an expanding number of clinical studies have examined NRF2 inducers targeting an ever-widening range of diseases. Full understanding of the pharmacokinetic and pharmacodynamic properties of drug candidates rely partly on the identification, validation, and use of biomarkers to optimize clinical applications. This review focuses on results from clinical trials with four agents known to target NRF2 signaling in preclinical studies (dimethyl fumarate, bardoxolone methyl, oltipraz, and sulforaphane), and evaluates the successes and limitations of biomarkers focused on expression of NRF2 target genes and others, inflammation and oxidative stress biomarkers, carcinogen metabolism and adduct biomarkers in unavoidably exposed populations, and targeted and untargeted metabolomics. While no biomarkers excel at defining pharmacodynamic actions in this setting, it is clear that these four lead clinical compounds do touch the NRF2 pathway in humans.

Calcium affects glucoraphanin metabolism in broccoli sprouts under ZnSO4 stress

CaCl₂, Ca²⁺ chelator (EGTA) and Ca²⁺ channel blocker (verapamil) were used to investigate mechanism of glucoraphanin metabolism in broccoli sprouts under ZnSO₄ stress. CaCl₂ treatment promoted sprout growth, reduced MDA (malonaldehyde) content and electrolyte leakage in sprouts under ZnSO₄ stress. The highest MDA content and electrolyte leakage were obtained in ZnSO₄ plus verapamil-treated sprouts. In addition, ZnSO₄ plus CaCl₂ treatment significantly enhanced glucoraphanin content and sulforaphane formation, while an opposite result was observed after ZnSO₄ plus EGTA treatment; which were further supported by expression of glucoraphanin biosynthetic and hydrolytic genes as well as myrosinase (MYR) and epithiospecifier protein (ESP) activities. These results indicated that exogenous and endogenous calcium promoted glucoraphanin biosynthesis and the conversion rate of glucoraphanin into sulforaphane. Verapamil treatment also stimulated glucoraphanin biosynthesis, but exerted an adverse influence on sulforaphane formation from the hydrolysis of glucoraphanin because of much higher ESP expression and ESP activity than ZnSO₄ treatment.

The interplay between oxidative stress and bioenergetic failure in neuropsychiatric illnesses: can we explain it and can we treat it?

Nitro-oxidative stress and lowered antioxidant defences play a key role in neuropsychiatric disorders such as major depression, bipolar disorder and schizophrenia. The first part of this paper details mitochondrial antioxidant mechanisms and their importance in reactive oxygen species (ROS) detoxification, including details of NO networks, the roles of H₂O₂ and the thioredoxin/peroxiredoxin system, and the relationship between mitochondrial respiration and NADPH production. The second part highlights and identifies the causes of the multiple pathological sequelae arising from self-amplifying increases in mitochondrial ROS production and bioenergetic failure. Particular attention is paid to NAD⁺ depletion as a core cause of pathology; detrimental effects of raised ROS and reactive nitrogen species on ATP and NADPH generation; detrimental effects of oxidative and nitrosative stress on the glutathione and thioredoxin systems; and the NAD⁺-induced signalling cascade, including the roles of SIRT1, SIRT3, PGC-1α, the FOXO family of transcription factors, Nrf1 and Nrf2. The third part discusses proposed therapeutic interventions aimed at mitigating such pathology, including the use of the NAD⁺ precursors nicotinamide mononucleotide and nicotinamide riboside, both of which rapidly elevate levels of NAD⁺ in the brain and periphery following oral administration; coenzyme Q₁₀ which, when given with the aim of improving mitochondrial function and reducing nitro-oxidative stress in the brain, may be administered via the use of mitoquinone, which is in essence ubiquinone with an attached triphenylphosphonium cation; and N-acetylcysteine, which is associated with improved mitochondrial function in the brain and produces significant decreases in oxidative and nitrosative stress in a dose-dependent manner.

Sulforaphane protects against skeletal muscle dysfunction in spontaneous type 2 diabetic db/db mice

AIMS

Skeletal muscle diseases have become to be the most common complication in patients with type 2 diabetic mellitus (T2DM). However, the effective therapies against skeletal muscle diseases are not yet available. Sulforaphane (SFN) is an organic isothiocyanate found in cruciferous plants. Our aim was to explore whether SFN could attenuate the skeletal muscle diseases in spontaneous type 2 diabetic db/db mice.

MATERIALS AND METHODS

The db/m and littermate db/db mice were treated with SFN or dimethyl sulfoxide. The grip strength of mice was measured by a grasping forcing machine. The electron transmission microscopy was used to perform the skeletal muscle. The western blot was used to detect the nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signal pathway related proteins, and inflammatory and apoptotic associated proteins. The mRNA levels of anti-inflammatory and anti-oxidative relative genes were detected by RT-QPCR.

KEY FINDINGS

We found that SFN could significantly increase the grip strength of the db/db mice. The lean mass and gastrocnemius mass were increased in the db/db mice after administration with SFN. Additionally, the db/db mice restored the skeletal muscle fiber organization after SFN treatment. Mechanistically, SFN could activate the Nrf2/HO-1 signal pathway, and downregulate the expression of inflammatory and apoptotic associated proteins. Furthermore, SFN could also regulate the mRNA levels of anti-inflammatory and anti-oxidative related genes.

SIGNIFICANCE

Our results demonstrated that SFN can protect against skeletal muscle diseases in db/db type 2 diabetic mice and provide a potential drug to prevent skeletal muscle dysfunction in T2DM patients.

Sesamol Increases Ucp1 Expression in White Adipose Tissues and Stimulates Energy Expenditure in High-Fat Diet-Fed Obese Mice

Sesamol found in sesame oil has been shown to ameliorate obesity by regulating lipid metabolism. However, its effects on energy expenditure and the underlying molecular mechanism have not been clearly elucidated. In this study, we show that sesamol increased the uncoupling protein 1 (Ucp1) expression in adipocytes. The administration of sesamol in high-fat diet (HFD)-fed mice prevented weight gain and improved metabolic derangements. The three-week sesamol treatment of HFD-fed mice, when the body weights were not different between the sesamol and control groups, increased energy expenditure, suggesting that an induced energy expenditure is a primary contributing factor for sesamol’s anti-obese effects. Consistently, sesamol induced the expression of energy-dissipating thermogenic genes, including Ucp1, in white adipose tissues. The microarray analysis showed that sesamol dramatically increased the Nrf2 target genes such as Hmox1 and Atf3 in adipocytes. Moreover, 76% (60/79 genes) of the sesamol-induced genes were also regulated by tert-butylhydroquinone (tBHQ), a known Nrf2 activator. We further verified that sesamol directly activated the Nrf2-mediated transcription. In addition, the Hmox1 and Ucp1 induction by sesamol was compromised in Nrf2-deleted cells, indicating the necessity of Nrf2 in the sesamol-mediated Ucp1 induction. Together, these findings demonstrate the effects of sesamol in inducing Ucp1 and in increasing energy expenditure, further highlighting the use of the Nrf2 activation in stimulating thermogenic adipocytes and in increasing energy expenditure in obesity and its related metabolic diseases.

The Potential for Reducing Lynch Syndrome Cancer Risk with Nutritional Nrf2 Activators

Lynch syndrome (LS), is an autosomal dominant disorder predisposing patients to multiple cancers, predominantly colorectal (CRC) and endometrial, and is implicated in 2-4% of all CRC cases. LS is characterized by mutations of four mismatch repair (MMR) genes which code for proteins responsible for recognizing and repairing DNA lesions occurring through multiple mechanisms including oxidative stress (OS). Increased OS can cause DNA mutations and is considered carcinogenic. Due to reduced MMR activity, LS patients have an increased risk of cancer as a result of a decreased ability to recognize and repair DNA lesions caused by OS. Due to its carcinogenic properties, reducing the level of OS may reduce the risk of cancer. Nutritional Nrf2 activators have been shown to reduce the risk of carcinogenesis in the general population through activation of the endogenous antioxidant system. Common nutritional Nrf2 activators include sulforaphane, curcumin, DATS, quercetin, resveratrol, and EGCG. Since LS patients are more susceptible to carcinogenesis caused by OS, it is hypothesized that nutritional Nrf2 activators may have the potential to reduce the risk of cancer in those with LS by modulating OS and inflammation. The purpose of this paper is to review the available evidence in support of this statement.

A low glycemic diet protects disease-prone Nrf2-deficient mice against age-related macular degeneration

Age-related macular degeneration (AMD) is a major blinding disease, affecting over 14% of the elderly. Risk for AMD is related to age, diet, environment, and genetics. Dietary modulation of AMD risk is a promising treatment modality, but requires appropriate animal models to demonstrate advantages of diet. Mice lacking the antioxidant transcription factor Nrf2 (Nfe2l2) develop age-related retinopathy relevant to human AMD. Here we evaluated the effect of consuming high glycemic (HG) or low glycemic (LG) diets until 18-months of age on development of features relevant to AMD in Nrf2-null mice. Nrf2-null mice that consumed HG diets developed atrophic AMD, characterized by photoreceptor degeneration, retinal pigment epithelium (RPE) atrophy and pigmentary abnormalities, basal laminar deposits, and loss of the choriocapillaris. In contrast, Nrf2-null-mice that consumed LG diets did not develop retinal disease phenotypes. Consumption of HG diets was associated with accumulation of advanced glycation end-products in the RPE and systemically, whereas consumption of the LG diet was associated with increased levels of anti-glycative and anti-oxidative detoxification machinery. Together our data indicate that the Nrf2-null HG mouse is a good model for atrophic AMD studies and that the LG diet can activate protective pathways to prevent AMD, even in a genetically predisposed animal.

Use of elicitation in the cultivation of Bimi® for food and ingredients

BACKGROUND

Cruciferous foods rich in health-promoting metabolites are of particular interest to consumers as well as being a good source of bioactives-enriched ingredients. Several elicitors have been used to stimulate the biosynthesis and accumulation of secondary metabolites in foods; however, little is known about the response of new hybrid varieties, such as Bimi®, under field-crop production conditions. Therefore, this study was designed to evaluate the effect of salicylic acid (200 μmol L^-1 , SA), methyl jasmonate (100 μmol L^-1 , MeJA), and their combination on Bimi plant organs (inflorescences and aerial vegetative tissues - stems and leaves). For this, the composition of the glucosinolates present in the tissues was evaluated. Also, aqueous extracts of the plant material, obtained with different times of extraction with boiling water, were studied.

RESULTS

The results indicate that the combined treatment (SA + MeJA) significantly increased the content of glucosinolates in the inflorescences and that MeJA was the most effective elicitor in leaves. Regarding the aqueous extracts, the greatest amount of glucosinolates was extracted at 30 min - except for the leaves elicited with MeJA, for which 15 min was optimal.

CONCLUSION

The elicitation in the field enriched leaves in glucobrassicin (GB), 4-methoxyglucobrassicin (MGB), and neoglucobrassicin (NGB) and stems and inflorescences in glucoraphanin, 4-hydroxyglucobrassicin, GB, MGB, and NGB. In this way, this enhanced vegetable material favored the presence of bioactives in the extracts, which is of great interest regarding enriched foods and ingredients with added value obtained from them. © 2019 Society of Chemical Industry.

Impact of Antioxidant Natural Compounds on the Thyroid Gland and Implication of the Keap1/Nrf2 Signaling Pathway

BACKGROUND

Natural compounds with potential antioxidant properties have been used in the form of food supplements or extracts with the intent to prevent or treat various diseases. Many of these compounds can activate the cytoprotective Nrf2 pathway. Besides, some of them are known to impact the thyroid gland, often with potential side-effects, but in other instances, with potential utility in the treatment of thyroid disorders.

OBJECTIVE

In view of recent data regarding the multiple roles of Nrf2 in the thyroid, this review summarizes the current bibliography on natural compounds that can have an effect on thyroid gland physiology and pathophysiology, and it discusses the potential implication of the Nrf2 system in the respective mechanisms.

METHODS & RESULTS

Literature searches for articles from 1950 to 2018 were performed in PubMed and Google Scholar using relevant keywords about phytochemicals, Nrf2 and thyroid. Natural substances were categorized into phenolic compounds, sulfur-containing compounds, quinones, terpenoids, or under the general category of plant extracts. For individual compounds in each category, respective data were summarized, as derived from in vitro (cell lines), preclinical (animal models) and clinical studies. The main emerging themes were as follows: phenolic compounds often showed potential to affect the production of thyroid hormones; sulfur-containing compounds impacted the pathogenesis of goiter and the proliferation of thyroid cancer cells; while quinones and terpenoids modified Nrf2 signaling in thyroid cell lines.

CONCLUSION

Natural compounds that modify the activity of the Nrf2 pathway should be evaluated carefully, not only for their potential to be used as therapeutic agents for thyroid disorders, but also for their thyroidal safety when used for the prevention and treatment of non-thyroidal diseases.

Biomimetics - Nature's roadmap to insights and solutions for burden of lifestyle diseases

There are over 8 million species in this world that live in widely varying environments, from hot thermal fissures to cold arctic settings. These species have evolved over millions of years and vary markedly in how they have adapted to their environments. In the last decades, studies of how species have succeeded in surviving in different environments and with different resources have been recognized to provide not only insights into disease but also novel means for developing treatments. Here, we provide an overview of two related and overlapping approaches (biomimetics and zoobiquity), which are turning to the natural world for insights to better understand, treat and prevent human 'burden of lifestyle' pathologies from heart disease and cancer to degeneration and premature ageing. We suggest that expanding biomedical investigation beyond its decades old conventional practices to new approaches based on a broad awareness of the diversity of animal life and comparative physiology can accelerate innovations in health care under the motto 'Nature knows best'.

Nrf2 in early vascular ageing: Calcification, senescence and therapy

Under normal physiological conditions, free radical generation and antioxidant defences are balanced, and reactive oxygen species (ROS) usually act as secondary messengers in a plethora of biological processes. However, when this balance is impaired, oxidative stress develops due to imbalanced redox homeostasis resulting in cellular damage. Oxidative stress is now recognized as a trigger of cellular senescence, which is associated with multiple chronic 'burden of lifestyle' diseases, including atherosclerosis, type-2 diabetes, chronic kidney disease and vascular calcification; all of which possess signs of early vascular ageing. Nuclear factor erythroid 2-related factor 2 (Nrf2), termed the master regulator of antioxidant responses, is a transcription factor found to be frequently dysregulated in conditions characterized by oxidative stress and inflammation. Recent evidence suggests that activation of Nrf2 may be beneficial in protecting against vascular senescence and calcification. Both natural and synthetic Nrf2 agonists have been introduced as promising drug classes in different phases of clinical trials. However, overexpression of the Nrf2 pathway has also been linked to tumorigenesis, which highlights the requirement for further understanding of pathways involving Nrf2 activity, especially in the context of cellular senescence and vascular calcification. Therefore, comprehensive translational pre-clinical and clinical studies addressing the targeting capabilities of Nrf2 agonists are urgently required. The present review discusses the impact of Nrf2 in senescence and calcification in early vascular ageing, with focus on the potential clinical implications of Nrf2 agonists and non-pharmacological Nrf2 therapeutics.

Recent progress in the development of small molecule Nrf2 activators: a patent review (2017-present)

Introduction: The transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2) is the first line of defense against a plethora of environmental or endogenous deviations in redox metabolism, proteostasis, inflammation, etc. Therefore, pharmacological activation of Nrf2 is a potential therapeutic approach for several diseases related to oxidative stress and inflammation, such as cancer, cardiovascular, and neurodegenerative diseases.Areas covered: The authors first describe the biological function of Nrf2 and the molecular regulatory mechanism of Keap1-Nrf2-ARE ((Kelch-like ECH-Associating protein 1)-Nrf2-(antioxidant response element)). Then, they review recent progress of covalent activators and non-covalent Keap1-Nrf2 protein-protein interaction (PPI) inhibitors from patents and publications in 2017-present, consisting of new chemical molecules, structure optimization of reported activators and progress in preclinical or clinical trials.Expert opinion: Despite significant achievements in the development of Nrf2 activators, the selectivity is the primary consideration. Due to reacting with redox-sensitive cysteines in proteins except for Keap1, electrophilic activators often exhibit off-target effects. For Keap1-Nrf2 PPI inhibitors, how to enhance in vivo efficacy and/or penetrate blood-brain barrier (BBB) to reach central nervous system (CNS) is also challenging. Fragment-based drug discovery (FBDD), carboxylic acid bioisosteric replacement and prodrug approach might be used to circumvent this challenge. Moreover, the possibility of cancer risk caused by Nrf2 activation needs to be considered carefully.

MicroRNAs as novel targets of sulforaphane in cancer therapy: The beginning of a new tale?

Effective management and treatment of cancer depend on developing novel antitumor drugs with the capability of targeting various molecular pathways. Identification and subsequent targeting of these pathways are of importance in cancer therapy. MicroRNAs (miRNAs) are small noncoding RNA molecules responsible for post-transcriptional regulation of genes. Notably, miRNAs participate in a number of biological processes such as proliferation, apoptosis, differentiation, and cell cycle regulation. So, any impairment in the expression and function of miRNAs is associated with development of disorders, particularly cancer. Naturally occurring nutraceutical compounds have attracted much attention due to their great antitumor activity. Among them, sulforaphane isolated from Brassica oleracea (broccoli) is of interest due to its therapeutic and biological activities such as antidiabetic, antioxidant, anti-inflammatory, hepatoprotection, and cardiprotection. Sulforaphane has demonstrated great antitumor activity and is able to significantly inhibit proliferation, viability, migration, malignancy, and epithelial-to-mesenchymal transition of cancer cells. These antitumor effects have widely been investigated, and it appears that there is a need for a precise review to demonstrate the molecular pathway that sulforaphane follows to exert its antitumor activity. At the present review, we focus on the modulatory impact of sulforaphane on miRNAs and exhibit that how various miRNAs in different cancers are regulated by sulforaphane.

Organic Isothiocyanates as Hydrogen Sulfide Donors

Significance: Hydrogen sulfide (H₂S), the "new entry" in the series of endogenous gasotransmitters, plays a fundamental role in regulating the biological functions of various organs and systems. Consequently, the lack of adequate levels of H₂S may represent the etiopathogenetic factor of multiple pathological alterations. In these diseases, the use of H₂S donors represents a precious and innovative opportunity. Recent Advances: Natural isothiocyanates (ITCs), sulfur compounds typical of some botanical species, have long been investigated because of their intriguing pharmacological profile. Recently, the ITC moiety has been proposed as a new H₂S-donor chemotype (with a l-cysteine-mediated reaction). Based on this recent discovery, we can clearly observe that almost all the effects of natural ITCs can be explained by the H₂S release. Consistently, the ITC function was also used as an original H₂S-releasing moiety for the design of synthetic H₂S donors and original "pharmacological hybrids." Very recently, the chemical mechanism of H₂S release, resulting from the reaction between l-cysteine and some ITCs, has been elucidated. Critical Issues: Available literature gives convincing demonstration that H₂S is the real player in ITC pharmacology. Further, countless studies have been carried out on natural ITCs, but this versatile moiety has been used only rarely for the design of synthetic H₂S donors with optimal drug-like properties. Future Directions: The development of more ITC-based synthetic H₂S donors with optimal drug-like properties and selectivity toward specific tissues/pathologies seem to represent a stimulating and indispensable prospect of future experimental activities.

Sulforaphane attenuates hexavalent chromium-induced cardiotoxicity via the activation of the Sesn2/AMPK/Nrf2 signaling pathway

Hexavalent chromium (Cr(vi)), the most toxic valence state of chromium, is widely present in industrial effluents and wastes. Sulforaphane (SFN), rich in Brassica genus plants, bears multiple biological activity. Wistar rats were used to explore the protective role of SFN against the cardiotoxicity of chronic potassium dichromate (K2Cr2O7) exposure and reveal the potential molecular mechanism. The data showed that SFN alleviated hematological variations, oxidative stress, heart dysfunction and structure disorder, and cardiomyocyte apoptosis induced by K2Cr2O7. Moreover, SFN reduced p53, cleaved caspase-3, Bcl2-associated X protein, nuclear factor kappa-B, and interleukin-1β levels, and increased Sesn2, nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1, NAD(P)H quinone oxidoreductase-1, and phosphorylated adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) levels. This study demonstrates that SFN ameliorates Cr(vi)-induced cardiotoxicity via activation of the Sesn2/AMPK/Nrf2 signaling pathway. SFN may be a protector against Cr(vi)-induced heart injury and a novel therapy for chronic Cr(vi) exposure.

STAT3 dictates β-cell apoptosis by modulating PTEN in streptozocin-induced hyperglycemia

Insufficient pancreatic β-cell mass or insulin-producing β-cells are implicated in all forms of diabetes mellitus. However, the molecular mechanisms underlying β-cell destruction are complex and not fully defined. Here we observed that activation of STAT3 is intensely and specifically inhibited in β-cells under hyperglycemic conditions. By knocking out STAT3 specifically in mouse β-cells, we found that the loss of STAT3 sensitized mice to three low doses of STZ stimulation resulting in hyperglycemia. Mechanistically, accumulating PTEN, induced by STAT3 deficiency, directly represses phosphorylation of AKT, which negatively modulates transcription factor activation, dysregulates β-cell function, positively promotes apoptotic signaling, and finally induces β-cell apoptosis. Notably, the defective secretion of insulin and β-cells apoptosis was completely rescued by PTEN ablation in STAT3-null islets or PTEN inhibitor bpv(phen) treatment. Thus our data suggest that STAT3 is a vital modulator of β-cell survival and function, highlighting a critical role for STAT3 in the negative regulation of PTEN-AKT signaling pathway associated with β-cell dysfunction and apoptosis.

Amelioration of Hyperglycemia-Induced Nephropathy by 3,3'-Diindolylmethane in Diabetic Mice

Type 1 diabetes mellitus (insulin-dependent diabetes) is characterized by hyperglycemia caused by an insulin deficiency. Diabetic nephropathy is a major complication of hyperglycemia. 3,3′-diindolylmethane (DIM)-a natural compound produced from indole-3-carbinol, found in cruciferous vegetables-enhances glucose uptake by increasing the activation of the insulin signaling pathway in 3T3-L1 adipocytes. In this study, we investigated whether DIM could improve insulin-dependent diabetes and nephropathy in streptozotocin (STZ)-induced diabetic mice. In mice, STZ induced hyperglycemia, hunger, thirst, and abnormally increased kidney weight and serum creatinine, which is a renal functional parameter. DIM decreased STZ-increased high blood glucose levels and food and water intake in diabetic mice. DIM also improved diabetic nephropathy by inhibiting the expression of PKC-α, the marker of albuminuria, and TGF-β1, an indicator of renal hypertrophy, in diabetic mice. Our findings suggest that DIM may ameliorate hyperglycemia and diabetic nephropathy through the inhibition of PKC-α and TGF-β1 signaling.

Sulforaphane protects from myocardial ischemia-reperfusion damage through the balanced activation of Nrf2/AhR

The activation of the transcription factor Nrf2 and the consequent increment in the antioxidant response might be a powerful strategy to contend against reperfusion damage. In this study we compared the effectiveness between sulforaphane (SFN), a well known activator of Nrf2 and the mechanical maneuver of post-conditioning (PostC) to confer cardioprotection in an in vivo cardiac ischemia-reperfusion model. We also evaluated if additional mechanisms, besides Nrf2 activation contribute to cardioprotection. Our results showed that SFN exerts an enhanced protective response as compared to PostC. Bot, strategies preserved cardiac function, decreased infarct size, oxidative stress and inflammation, through common protective pathways; however, the aryl hydrocarbon receptor (AhR) also participated in the protection conferred by SFN. Our data suggest that SFN-mediated cardioprotection involves transient Nrf2 activation, followed by phase I enzymes upregulation at the end of reperfusion, as a long-term protection mechanism.

Sulforaphane: Its "Coming of Age" as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease

A growing awareness of the mechanisms by which phytochemicals can influence upstream endogenous cellular defence processes has led to intensified research into their potential relevance in the prevention and treatment of disease. Pharmaceutical medicine has historically looked to plants as sources of the starting materials for drug development; however, the focus of nutraceutical medicine is to retain the plant bioactive in as close to its native state as possible. As a consequence, the potency of a nutraceutical concentrate or an extract may be lower than required for significant gene expression. The molecular structure of bioactive phytochemicals to a large extent determines the molecule's bioavailability. Polyphenols are abundant in dietary phytochemicals, and extensive in vitro research has established many of the signalling mechanisms involved in favourably modulating human biochemical pathways. Such pathways are associated with core processes such as redox modulation and immune modulation for infection control and for downregulating the synthesis of inflammatory cytokines. Although the relationship between oxidative stress and chronic disease continues to be affirmed, direct-acting antioxidants such as vitamins A, C, and E, beta-carotene, and others have not yielded the expected preventive or therapeutic responses, even though several large meta-analyses have sought to evaluate the potential benefit of such supplements. Because polyphenols exhibit poor bioavailability, few of their impressive in vitro findings have been replicated in vivo. SFN, an aliphatic isothiocyanate, emerges as a phytochemical with comparatively high bioavailability. A number of clinical trials have demonstrated its ability to produce favourable outcomes in conditions for which there are few satisfactory pharmaceutical solutions, foreshadowing the potential for SFN as a clinically relevant nutraceutical. Although myrosinase-inert broccoli sprout extracts are widely available, there now exist myrosinase-active broccoli sprout supplements that yield sufficient SFN to match the doses used in clinical trials.

Broccoli or Sulforaphane: Is It the Source or Dose That Matters?

There is robust epidemiological evidence for the beneficial effects of broccoli consumption on health, many of them clearly mediated by the isothiocyanate sulforaphane. Present in the plant as its precursor, glucoraphanin, sulforaphane is formed through the actions of myrosinase, a β-thioglucosidase present in either the plant tissue or the mammalian microbiome. Since first isolated from broccoli and demonstrated to have cancer chemoprotective properties in rats in the early 1990s, over 3000 publications have described its efficacy in rodent disease models, underlying mechanisms of action or, to date, over 50 clinical trials examining pharmacokinetics, pharmacodynamics and disease mitigation. This review evaluates the current state of knowledge regarding the relationships between formulation (e.g., plants, sprouts, beverages, supplements), bioavailability and efficacy, and the doses of glucoraphanin and/or sulforaphane that have been used in pre-clinical and clinical studies. We pay special attention to the challenges for better integration of animal model and clinical studies, particularly with regard to selection of dose and route of administration. More effort is required to elucidate underlying mechanisms of action and to develop and validate biomarkers of pharmacodynamic action in humans. A sobering lesson is that changes in approach will be required to implement a public health paradigm for dispensing benefit across all spectrums of the global population.

Minimizing Hyperglycemia-Induced Vascular Endothelial Dysfunction by Inhibiting Endothelial Sodium-Glucose Cotransporter 2 and Attenuating Oxidative Stress: Implications for Treating Individuals With Type 2 Diabetes

This overview deals with mechanisms whereby hyperglycemia-induced oxidative stress compromises vascular endothelial function and provides a background for a recently published study illustrating the beneficial impact of endothelial sodium-glucose cotransporter 2 (SGLT2) inhibitors in attenuating hyperglycemia-induced vascular dysfunction in vitro. The data provide new insight that can possibly lead to improved drug therapy for people with type 2 diabetes. The working hypotheses that underpinned the experiments performed are provided, along with the findings of the study. For the causes of hyperglycemia-induced vascular endothelial dysfunction, the findings point to the key roles of: 1) functional endothelial SGLT2; 2) oxidative stress-induced signalling pathways including mammalian sarcoma virus kinase, the EGF receptor-kinase and protein kinase C; and 3) mitochondrial dysfunction triggered by hyperglycemia was mitigated by an SGLT2 inhibitor in the hyperglycemic mouse aorta vascular organ cultures. The overview sums up the approaches implicated by the study that can potentially counteract the detrimental impact of hyperglycemia on vascular function in people with diabetes, including the clinical use of SGLT2 inhibitors for those with type 2 diabetes already being treated, for example, with metformin, along with dietary supplementation with broccoli-derived sulforaphane and tetrahydrobiopterin. The caveats associated with the study for extending the findings from mice to humans are summarized, pointing to the need to validate the work using vascular tissues from humans. Suggestions for future clinical studies are made, including the assessment of the impact of the therapeutic strategies proposed on measurements of blood flow in subjects with diabetes.

Broccoli sprouts juice prevents lens protein aggregation in streptozotocin-induced diabetic rat

AIM

To investigate the effect of broccoli sprouts juice in preventing lens protein aggregation in diabetic rat model.

METHODS

Totally 25 male Wistar rats were divided into negative control group, diabetic group without juice treatment as positive control and diabetic group given broccoli sprouts juice 0.25, 0.5 and 1 g/d for 28d. Diabetic rat model was obtained by administering a single dose streptozotocin 65 mg/kg intraperitoneal. At the end of the study, all rats were examined for fasting blood sugar level (FBS), visual cataract score using slit lamp biomicroscope and lens αB-crystallin expression using Western blot method. Statistical analysis was performed using one way ANOVA with post hoc test, correlation test, and simple linear regression.

RESULTS

Positive control group had the highest cataract score and lens aggregated αB-crystallin expression. Broccoli sprout juice dose of 1 g/d group had the mildest cataract score, as well as the expression of lens aggregated αB-crystallin compared to treatments groups 1 and 2, opposite to lens native αB-crystallin expression. The broccoli sprout juice groups gave a significant decrease in cataract score, and also in lens aggregated αB-crystallin expression in diabetic rat models (P<0.05).

CONCLUSION

Broccoli sprout juice has a significant effect in preventing lens protein aggregation in diabetic rat model. The higher dose gives better visual cataract scores, lower lens aggregated αB-crystallin expression and higher lens native αB-crystallin expression.

A Bibliometric Review of the Keap1/Nrf2 Pathway and its Related Antioxidant Compounds

Nrf2 is a master transcriptional regulator of antioxidant and cytoprotective pathways. Currently in its third decade, research on Nrf2 has expanded to encompass not only basic but also clinical studies. In the present bibliometric review, we employed the VOSviewer tool to describe the existing Nrf2 literature landscape. As of July 2019, 11,931 papers on Nrf2 were listed in the “Web of Science” database, with more than 1000 new papers published each year. As expected, terms related to oxidative stress and antioxidant molecules occur very often in the Nrf2 literature throughout the years. Interestingly, there is also a gradual increase in the occurrence of terms related to diseases or to natural compounds, the most prominent being sulforaphane, curcumin, and resveratrol that modulate the Nrf2 pathway. Going beyond molecular biology/biochemistry and related fields, Nrf2 research has begun to spread into more clinical areas like endocrinology/metabolism, cardiology, and nephrology, likely reflecting an increased interest in clinical applications of Nrf2 pathway activators. China has become the most prolific producer of Nrf2 papers the last five years followed by the USA and Japan, a reverse pattern compared to the past. In conclusion, Nrf2 is the subject of a globally active research field that keeps growing and extends from bench to bedside.

Eruca sativa Meal against Diabetic Neuropathic Pain: An H2S-Mediated Effect of Glucoerucin

The management of pain in patients affected by diabetic neuropathy still represents an unmet therapeutic need. Recent data highlighted the pain-relieving efficacy of glucosinolates deriving from Brassicaceae. The purpose of this study was to evaluate the anti-hyperalgesic efficacy of Eruca sativa defatted seed meal, along with its main glucosinolate, glucoerucin (GER), on diabetic neuropathic pain induced in mice by streptozotocin (STZ). The mechanism of action was also investigated. Hypersensitivity was assessed by paw pressure and cold plate tests after the acute administration of the compounds. Once bio-activated by myrosinase, both E. sativa defatted meal (1 g kg⁻¹ p.o.) and GER (100 µmol kg⁻¹ p.o., equimolar to meal content) showed a dose-dependent pain-relieving effect in STZ-diabetic mice, but the meal was more effective than the glucosinolate. The co-administration with H₂S scavengers abolished the pain relief mediated by both E. sativa meal and GER. Their effect was also prevented by selectively blocking Kv7 potassium channels. Repeated treatments with E. sativa meal did not induce tolerance to the anti-hypersensitive effect. In conclusion, E. sativa meal can be suggested as a new nutraceutical tool for pain relief in patients with diabetic neuropathy.

Rare and common genetic variations in the Keap1/Nrf2 antioxidant response pathway impact thyroglobulin gene expression and circulating levels, respectively

Nuclear factor, erythroid 2-like 2 (Nrf2) is a transcription factor that has been gaining attention in the field of pharmacology and especially in the chemoprevention of diseases such as cancer, metabolic and neurodegenerative diseases, etc. This is because natural compounds such as sulforaphane, which is found in broccoli sprout extracts, can activate Nrf2. The repertoire of the roles of Nrf2 is ever increasing; besides its traditional antioxidant and cytoprotective effects, Nrf2 can have other functions as a transcription factor. We have recently shown that Nrf2 directly regulates the expression of thyroglobulin (Tg), which is the most abundant thyroidal protein and the precursor of thyroid hormones. Two functional binding sites for Nrf2 (antioxidant response elements, AREs) were identified in the regulatory region of the TG gene. Interestingly, we then observed that one of these AREs harbors a rare single-nucleotide polymorphism (SNP). Also recently, we performed the first genome-wide association study (GWAS) for common SNPs that impact the circulating levels of Tg. Based on these investigations, we were triggered (i) to investigate whether common SNPs in the Nrf2 pathway correlate with circulating Tg levels; and (ii) to examine whether the rare SNP in one of the TG regulatory AREs may affect gene expression. To address the first question, we analyzed GWAS data from a general population and its two subpopulations, one with thyroid disease and/or abnormal thyroid function tests and the other without, in which circulating Tg levels had been measured. Statistically significant associations with Tg levels were observed in the genes encoding Nrf2 and Keap1, including, notably, a known functional SNP in the promoter of the gene encoding Nrf2. Regarding the rare SNP (rs778940395) in the proximal ARE of the TG enhancer, luciferase reporter gene expression studies in PCCL3 rat thyroid follicular cells showed that this SNP abrogated the basal and sulforaphane- or TSH-induced luciferase activity, behaving as a complete loss-of-function mutation. Thus, both rare and common genetic variation in the Keap1/Nrf2 pathway can impact TG expression and Tg circulating levels, respectively.

Targeting PLIN2/PLIN5-PPARγ: Sulforaphane Disturbs the Maturation of Lipid Droplets

SCOPE

The effects of sulforaphane (SFN) on the maturation of lipid droplets (LDs)-the storage units for free fatty acids and sterols as triacylglycerides (TAG) and cholesterol esters (CE)-are far from being understood, despite the fact that SFN is known to be beneficial for ameliorating lipid metabolism disorders.

METHODS AND RESULTS

High-fat-intake models are established in both HHL-5 hepatocytes and rodents. The numbers and sizes of LDs are decreased by SFN. The accumulation of lipid core components (TAG & CE) is reduced and the expression of their key synthetases, acyl-coenzyme A: diacylglycerol acyltransferases 2 (DGAT2) and acyl-coenzyme A: cholesterol acyltransferases 1 (ACAT1), is also inhibited. Moreover, SFN decreases LD-associated protein PLIN2 and PLIN5 expression, but not that of PLIN1 and PLIN3, both in vivo and in vitro. Furthermore, over-expression of peroxisome proliferator-activated receptor gamma (PPARγ) induces the accumulation of TAG and the up-regulation of PLIN2 and PLIN5, which are not reversed by SFN. These results suggest that PPARγ may be a target of SFN in lipid metabolism.

CONCLUSION

SFN disturbs LD maturation by inhibiting the formation of the neutral lipid core and decreases PLIN2 and PLIN5 via down-regulation of PPARγ.

Connectivity Mapping: Methods and Applications

Connectivity mapping resources consist of signatures representing changes in cellular state following systematic small-molecule, disease, gene, or other form of perturbations. Such resources enable the characterization of signatures from novel perturbations based on similarity; provide a global view of the space of many themed perturbations; and allow the ability to predict cellular, tissue, and organismal phenotypes for perturbagens. A signature search engine enables hypothesis generation by finding connections between query signatures and the database of signatures. This framework has been used to identify connections between small molecules and their targets, to discover cell-specific responses to perturbations and ways to reverse disease expression states with small molecules, and to predict small-molecule mimickers for existing drugs. This review provides a historical perspective and the current state of connectivity mapping resources with a focus on both methodology and community implementations.

Activators and Inhibitors of NRF2: A Review of Their Potential for Clinical Development

The transcription factor NRF2 (nuclear factor erythroid 2-related factor 2) triggers the first line of homeostatic responses against a plethora of environmental or endogenous deviations in redox metabolism, proteostasis, inflammation, etc. Therefore, pharmacological activation of NRF2 is a promising therapeutic approach for several chronic diseases that are underlined by oxidative stress and inflammation, such as neurodegenerative, cardiovascular, and metabolic diseases. A particular case is cancer, where NRF2 confers a survival advantage to constituted tumors, and therefore, NRF2 inhibition is desired. This review describes the electrophilic and nonelectrophilic NRF2 activators with clinical projection in various chronic diseases. We also analyze the status of NRF2 inhibitors, which at this time provide proof of concept for blocking NRF2 activity in cancer therapy.

Looking beyond PGC-1α: emerging regulators of exercise-induced skeletal muscle mitochondrial biogenesis and their activation by dietary compounds

Despite its widespread acceptance as the "master regulator" of mitochondrial biogenesis (i.e., the expansion of the mitochondrial reticulum), peroxisome proliferator-activated receptor (PPAR) gamma coactivator-1 alpha (PGC-1α) appears to be dispensable for the training-induced augmentation of skeletal muscle mitochondrial content and respiratory function. In fact, a number of regulatory proteins have emerged as important players in skeletal muscle mitochondrial biogenesis and many of these proteins share key attributes with PGC-1α. In an effort to move past the simplistic notion of a "master regulator" of mitochondrial biogenesis, we highlight the regulatory mechanisms by which nuclear factor erythroid 2-related factor 2 (Nrf2), estrogen-related receptor gamma (ERRγ), PPARβ, and leucine-rich pentatricopeptide repeat-containing protein (LRP130) may contribute to the control of skeletal muscle mitochondrial biogenesis. We also present evidence supporting/refuting the ability of sulforaphane, quercetin, and epicatechin to promote skeletal muscle mitochondrial biogenesis and their potential to augment mitochondrial training adaptations. Targeted activation of specific pathways by these compounds may allow for greater mechanistic insight into the molecular pathways controlling mitochondrial biogenesis in human skeletal muscle. Dietary activation of mitochondrial biogenesis may also be useful in clinical populations with basal reductions in mitochondrial protein content, enzyme activities, and/or respiratory function as well as individuals who exhibit a blunted skeletal muscle responsiveness to contractile activity. Novelty The existence of redundant pathways leading to mitochondrial biogenesis refutes the simplistic notion of a "master regulator" of mitochondrial biogenesis. Dietary activation of specific pathways may provide greater mechanistic insight into the exercise-induced mitochondrial biogenesis in human skeletal muscle.

Sulforaphane Prevents Hepatic Insulin Resistance by Blocking Serine Palmitoyltransferase 3-Mediated Ceramide Biosynthesis

Sulforaphane (SFA), a naturally active isothiocyanate compound from cruciferous vegetables used in clinical trials for cancer treatment, was found to possess potency to alleviate insulin resistance. But its underlying molecular mechanisms are still incompletely understood. In this study, we assessed whether SFA could improve insulin sensitivity and glucose homeostasis both in vitro and in vivo by regulating ceramide production. The effects of SFA on glucose metabolism and expression levels of key proteins in the hepatic insulin signaling pathway were evaluated in insulin-resistant human hepatic carcinoma HepG2 cells. The results showed that SFA dose-dependently increased glucose uptake and intracellular glycogen content by regulating the insulin receptor substrate 1 (IRS-1)/protein kinase B (Akt) signaling pathway in insulin-resistant HepG2 cells. SFA also reduced ceramide contents and downregulated transcription of ceramide-related genes. In addition, knockdown of serine palmitoyltransferase 3 (SPTLC3) in HepG2 cells prevented ceramide accumulation and alleviated insulin resistance. Moreover, SFA treatment improved glucose tolerance and insulin sensitivity, inhibited SPTLC3 expression and hepatic ceramide production and reduced hepatic triglyceride content in vivo. We conclude that SFA recovers glucose homeostasis and improves insulin sensitivity by blocking ceramide biosynthesis through modulating SPTLC3, indicating that SFA may be a potential candidate for prevention and amelioration of hepatic insulin resistance via a ceramide-dependent mechanism.

Metabolic and Epigenetic Action Mechanisms of Antidiabetic Medicinal Plants

Diabetes is a predominant metabolic disease nowadays due to the off-beam lifestyle of diet and reduced physical activity. Complications of the illness include the gene-environment interactions and the downstream genetic and epigenetic consequences, e.g., cardiovascular diseases, tumor progression, retinopathy, nephropathy, neuropathy, polydipsia, polyphagia, polyuria, and weight loss. This review sheds the light on the mechanistic insights of antidiabetic medicinal plants in targeting key organs and tissues involved in regulating blood glucose homeostasis including the pancreas, liver, muscles, adipose tissues, and glucose absorption in the intestine. Diabetes is also involved in modulating major epigenetic pathways such as DNA methylation and histone modification. In this respect, we will discuss the phytochemicals as current and future epigenetic drugs in the treatment of diabetes. In addition, several proteins are common targets for the treatment of diabetes. Some phytochemicals are expected to directly interact with these targets. We lastly uncover modeling studies that predict such plausible interactions. In conclusion, this review article presents the mechanistic insight of phytochemicals in the treatment of diabetes by combining both the cellular systems biology and molecular modeling.

Progerin accumulation in nucleus pulposus cells impairs mitochondrial function and induces intervertebral disc degeneration and therapeutic effects of sulforaphane

Progerin, a truncated unprocessed lamin A protein, causes tissue aging and degeneration. In this study we explored the role of progerin in the pathogenesis of intervertebral disc degeneration (IDD). We also examined the effect of sulforaphane (SFN) on progerin accumulation and mitochondrial dysfunction in IDD.

Methods: The role of progerin in IDD was explored using human nucleus pulposus (NP) tissues, rat NP cells, and Lmna G609G knock-in mice. Immunostaining, X-ray imaging, and Western blotting were performed to assess the phenotypes of intervertebral discs. Alterations in senescence and apoptosis were evaluated by SA-β-galactosidase, immunofluorescence, flow cytometry, and TUNEL assays. Mitochondrial function was investigated by JC-1 staining, transmission electron microscopy, and determination of the level of ATP and the activities of mitochondrial enzymes.

Results: The progerin level was elevated in degenerated human NP tissues. Lmna G609G/G609G mice displayed IDD, as evidenced by increased matrix metalloproteinase-13 expression and decreased collagen II and aggrecan expression and disc height. Furthermore, progerin overexpression in rat NP cells induced mitochondrial dysfunction (decreased ATP synthesis, mitochondrial membrane potential, and activities of mitochondrial complex enzymes), morphologic abnormalities, and disrupted mitochondrial dynamic (abnormal expression of proteins involved in fission and fusion), resulting in apoptosis and senescence. SFN ameliorated the progerin-induced aging defects and mitochondrial dysfunction in NP cells and IDD in Lmna G609G/G609G mice.

Conclusions: Progerin is involved in the pathogenesis of IDD. Also, SFN alleviates progerin‑induced IDD, which is associated with amelioration of aging defects and mitochondrial dysfunction. Thus, SFN shows promise for the treatment of IDD.

Potential Applications of NRF2 Inhibitors in Cancer Therapy

The NRF2/KEAP1 pathway represents one of the most important cell defense mechanisms against exogenous or endogenous stressors. Indeed, by increasing the expression of several cytoprotective genes, the transcription factor NRF2 can shelter cells and tissues from multiple sources of damage including xenobiotic, electrophilic, metabolic, and oxidative stress. Importantly, the aberrant activation or accumulation of NRF2, a common event in many tumors, confers a selective advantage to cancer cells and is associated to malignant progression, therapy resistance, and poor prognosis. Hence, in the last years, NRF2 has emerged as a promising target in cancer treatment and many efforts have been made to identify therapeutic strategies aimed at disrupting its prooncogenic role. By summarizing the results from past and recent studies, in this review, we provide an overview concerning the NRF2/KEAP1 pathway, its biological impact in solid and hematologic malignancies, and the molecular mechanisms causing NRF2 hyperactivation in cancer cells. Finally, we also describe some of the most promising therapeutic approaches that have been successfully employed to counteract NRF2 activity in tumors, with a particular emphasis on the development of natural compounds and the adoption of drug repurposing strategies.

Current Status and Challenges of NRF2 as a Potential Therapeutic Target for Diabetic Cardiomyopathy

Diabetic cardiomyopathy is one of the main causes of heart failure and death in patients with diabetes mellitus. Reactive oxygen species produced excessively in diabetes mellitus cause necrosis, apoptosis, ferroptosis, inflammation, and fibrosis of the myocardium as well as impair the cardiac structure and function. It is increasingly clear that oxidative stress is a principal cause of diabetic cardiomyopathy. The transcription factor nuclear factor-erythroid 2 p45-related factor 2 (NRF2) activates the transcription of more than 200 genes in the human genome. Most of the proteins translated from these genes possess anti-oxidant, anti-inflammatory, anti-apoptotic, anti-ferroptotic, and anti-fibrotic actions. There is a growing body of evidence indicating that NRF2 and its target genes are crucial in preventing high glucose-induced oxidative damage in diabetic cardiomyopathy. Recently, many natural and synthetic activators of NRF2 are shown to possess promising therapeutic effects on diabetic cardiomyopathy in animal models of diabetic cardiomyopathy. Targeting NRF2 signaling by pharmacological entities is a potential approach to ameliorating diabetic cardiomyopathy. However, the persistent high expression of NRF2 in cancer tissues also protects the growth of cancer cells. This "dark side" of NRF2 increases the challenges of using NRF2 activators to treat diabetic cardiomyopathy. In addition, some NRF2 activators were found to have off-target effects. In this review, we summarize the current status and challenges of NRF2 as a potential therapeutic target for diabetic cardiomyopathy.

Therapeutic targeting of the NRF2 and KEAP1 partnership in chronic diseases

The transcription factor NF-E2 p45-related factor 2 (NRF2; encoded by NFE2L2) and its principal negative regulator, the E3 ligase adaptor Kelch-like ECH-associated protein 1 (KEAP1), are critical in the maintenance of redox, metabolic and protein homeostasis, as well as the regulation of inflammation. Thus, NRF2 activation provides cytoprotection against numerous pathologies including chronic diseases of the lung and liver; autoimmune, neurodegenerative and metabolic disorders; and cancer initiation. One NRF2 activator has received clinical approval and several electrophilic modifiers of the cysteine-based sensor KEAP1 and inhibitors of its interaction with NRF2 are now in clinical development. However, challenges regarding target specificity, pharmacodynamic properties, efficacy and safety remain.

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.

Sorting out the Value of Cruciferous Sprouts as Sources of Bioactive Compounds for Nutrition and Health

Edible sprouts with germinating seeds of a few days of age are naturally rich in nutrients and other bioactive compounds. Among them, the cruciferous (Brassicaceae) sprouts stand out due to their high contents of glucosinolates (GLSs) and phenolic compounds. In order to obtain sprouts enriched in these phytochemicals, elicitation is being increasing used as a sustainable practice. Besides, the evidence regarding the bioavailability and the biological activity of these compounds after their dietary intake has also attracted growing interest in recent years, supporting the intake of the natural food instead of enriched ingredients or extracts. Also, there is a growing interest regarding their uses, consumption, and applications for health and wellbeing, in different industrial sectors. In this context, the present review aims to compile and update the available knowledge on the fundamental aspects of production, enrichment in composition, and the benefits upon consumption of diverse edible cruciferous sprouts, which are sources of phenolic compounds and glucosinolates, as well as the evidence on their biological actions in diverse pathophysiological situations and the molecular pathways involved.

Moringa Isothiocyanate Activates Nrf2: Potential Role in Diabetic Nephropathy

Moringa isothiocyanate (MIC-1) is the main active isothiocyanate found in Moringa oleifera, a plant consumed as diet and traditional herbal medicine. Compared to sulforaphane (SFN), MICs are less studied and most work have focused on its anti-inflammatory activity. The purpose of this study is to better understand the Nrf2-ARE antioxidant activity of MIC-1 and its potential in diabetic nephropathy. MIC-1 showed little toxicity from 1.25-5 μM. MIC-1 activated Nrf2-ARE at similar levels to SFN. MIC-1 also increased gene expression of downstream Nrf2 genes NQO1, HO-1, and GCLC. Protein expression of HO-1 and GCLC was elevated in MIC-1-treated cells versus control. MIC-1 suppressed pro-inflammatory cytokines in LPS-stimulated macrophages. MIC-1 reduced levels of reactive oxygen species in high glucose (HG)-treated human renal proximal tubule HK-2 cells. RNA-seq was performed to examine the transcriptome in HK-2 cells exposed to HG with or without MIC-1. Ingenuity Pathway Analysis (IPA) of RNA-seq on HK-2 cells exposed to HG identified TGFβ1 and NQO1 regulation as potentially impacted and treatment of HG-exposed HK-2 cells with MIC-1 reversed the gene expression of these two pathways. Results implicate that the transcriptional regulator TGFβ1 signaling is activated by HG and that MIC-1 can inhibit HG-stimulated TGFβ1 activation. In summary, MIC-1 activates Nrf2-ARE signaling, increases expression of Nrf2 target genes, and suppresses inflammation, while also reducing oxidative stress and possibly TGFβ1 signaling in high glucose induced renal cells. Taken together, it appears that one potential therapeutic strategy for managing DN and is currently under development in clinic is Nrf2 activation.

Broccoli sprout beverage is safe for thyroid hormonal and autoimmune status: Results of a 12-week randomized trial

Sulforaphane is a redox-active natural product present in cruciferous vegetables like broccoli. Broccoli sprout-derived products are promising agents for the prevention of oxidative stress-related diseases, but some have long been suspected of thyroidal toxicity. Recent findings also raise the possibility that long-term exposure to sulforaphane, or to other natural substances or drugs that modulate the activity of the transcription factor Nrf2 (NFE2-related factor 2) may lead to thyroid dysfunction or thyroid autoimmune disease, questioning the safety of trials with sulforaphane-containing products. Previous studies addressing possible effects of sulforaphane-related compounds from natural product extracts on the thyroid were quite short and/or inconsistent. To investigate whether long-term exposure to a beverage enriched with sulforaphane and its precursor glucoraphanin may affect thyroid function, we analyzed biochemical measures of thyroid function and thyroid autoimmunity in 45 female participants in a randomized clinical trial at baseline and after 84 days of beverage administration. Serum levels of thyroid-stimulating hormone, free thyroxine and thyroglobulin were not affected by the treatment, and neither was the thyroid autoimmunity status of participants. These results provide evidence in favor of the safety of chemoprevention strategies that target the activation of Nrf2 to protect against environmental exposures and other oxidative stress-related pathologies.

Comparison of the effects of sulforaphane and pioglitazone on insulin resistance and associated dyslipidemia, hepatosteatosis, and endothelial dysfunction in fructose-fed rats

The purpose of this work was to compare the influences of sulforaphane (SFN) to those of the standard insulin sensitizer pioglitazone (PIO) on high fructose diet (HFrD)-induced insulin resistance, dyslipidemia, hepatosteatosis, and vascular dysfunction in rats. Male Sprague Dawley rats (150-200 g) were fed on a standard diet (control) or a high fructose diet (HFrD, 60% w/w fructose) for 60 days. From day 16, two subgroups of HFrD-fed rats received either SFN (0.5 mg/kg/day, orally) or PIO (5 mg/kg/day, orally) along with HFrD until the end of the experiment. Fructose-fed rats showed significant decreases in food intake, body weight and feeding efficiency; effects that were not altered by either treatment. Data from insulin tolerance test (ITT), oral glucose tolerance test (OGTT), and HOMA-IR and HOMA-β indices demonstrated impaired insulin sensitivity and glucose utilization in HFrD-fed rats. SFN and PIO treatments significantly reduced OGTT_AUC (Glass's Delta values = 1.12 and 0.84, respectively), decreased ITT_AUC (Glass's Delta values = 1.05 and 0.71, respectively), significantly diminished HOMA-IR index (by 55.6% and 77.6%, respectively), and increased HOMA-β value (by 1.8 and 1.3 fold, respectively) compared to the HFrD rats. Moreover, SFN and PIO ameliorated hepatic oxidative stress and reduced serum levels of C-reactive protein and lactate dehydrogenase in HFrD-fed rats. Furthermore, SFN and PIO administrations improved insulin resistance-associated heaptosteatosis and enhanced vascular responsiveness to acetylcholine-induced relaxations. However, only SFN was able to enhance serum HDL-C levels in HFrD group. These finding suggests that SFN elicited insulin-sensitizing, hepatoprotective, and vasculoprotective effects in HFrD insulin-resistant rats that were comparable to those exerted by PIO.

Sulforaphane Improves Lipid Metabolism by Enhancing Mitochondrial Function and Biogenesis In Vivo and In Vitro

SCOPE

Sulforaphane (SFN) is reported to reduce the accumulation of lipids. However, the underling mechanism remains unclear. In this study, the potential of SFN to improve lipid metabolism is investigated through altering mitochondrial function and biogenesis-related mechanisms.

METHODS AND RESULTS

The abnormal lipid metabolism model was established both in HHL-5 cells and in rats by feeding a high-fat diet (HFD) for 10 weeks. The current findings suggest that SFN alleviates the swelling of mitochondria and stimulates mitochondrial biogenesis. The reduced expression of NRF1 and TFAM, were reversed by SFN. SFN increases the levels of antioxidant compounds via nuclear factor erythroid-2-related factor (Nrf2) activation. Furthermore, SFN improves multiple mitochondrial bioactivities, such as mitochondrial membrane potential, ATP, and the electron transfer chain based on PGC-1α pathway. SFN also activates lipolysis by transcriptionally upregulating adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL).

CONCLUSIONS

SFN enhances utilization of lipids via both the PGC- 1α-dependent promotion of mitochondrial biogenesis and Nrf2 dependent improvement of mitochondrial function.

Nrf2 represses the onset of type 1 diabetes in non-obese diabetic mice

The transcription factor Nrf2 (NF-E2-related factor 2) plays a critical role in oxidative stress responses. While activation of Nrf2 signaling is known to exert anti-inflammatory effects, Nrf2 function in inflammation-mediated autoimmune disorders, such as type 1 diabetes, is not well established. To address the roles of Nrf2 in protection against autoreactive T-cell-induced type 1 diabetes, we used non-obese diabetic (NOD) mice, a polygenic model of human type 1 diabetes, to generate a genetic model that allowed us to assess the contribution of Nrf2 activation to preventing and/or treating type 1 diabetes. As Keap1 negatively regulates Nrf2, we used Keap1 gene knockdown driven by either hypomorphic or knockout alleles of Keap1,which enhances Nrf2 signaling to moderate and excess levels, respectively. We found that Nrf2 activation in NOD::Keap1FA/- mice inhibited T-cell infiltration within or near the islets, ameliorated impairment of insulin secretion, and prevented development of diabetes mellitus in the NOD mice. Notably, Nrf2 activation decreased both plasma interferon-γ (IFN-γ) levels and IFN-γ-positive cell numbers in the pancreatic islets. These findings were also observed in mice with two hypomorphic Keap1 alleles (Keap1FA/FA). Both NOD::Keap1FA/- and NOD::Keap1FA/FA mice had decreased incidence of diabetes mellitus, demonstrating that the activation of Nrf2 signaling prevents the onset of type 1 diabetes mellitus in NOD mice. Thus, Nrf2 appears to be a potential target for preventing and treating type 1 diabetes.