Metabolic effects of sulforaphane oral treatment in streptozotocin-diabetic rats

Unveiling the Nutritional Veil of Sulforaphane: With a Major Focus on Glucose Homeostasis Modulation

Abnormal glucose homeostasis is associated with metabolic syndromes including cardiovascular diseases, hypertension, type 2 diabetes mellitus, and obesity, highlighting the significance of maintaining a balanced glucose level for optimal biological function. This highlights the importance of maintaining normal glucose levels for proper biological functioning. Sulforaphane (SFN), the primary bioactive compound in broccoli from the Cruciferae or Brassicaceae family, has been shown to enhance glucose homeostasis effectively while exhibiting low cytotoxicity. This paper assesses the impact of SFN on glucose homeostasis in vitro, in vivo, and human trials, as well as the molecular mechanisms that drive its regulatory effects. New strategies have been proposed to enhance the bioavailability and targeted delivery of SFN in order to overcome inherent instability. The manuscript also covers the safety evaluations of SFN that have been documented for its production and utilization. Hence, a deeper understanding of the favorable influence and mechanism of SFN on glucose homeostasis, coupled with the fact that SFN is abundant in the human daily diet, may ultimately offer theoretical evidence to support its potential use in the food and pharmaceutical industries.

Sulforaphane Ameliorates High-Fat-Diet-Induced Metabolic Abnormalities in Young and Middle-Aged Obese Male Mice

Type 2 diabetes (T2D) is still a fast-growing health problem globally. It is evident that chronic insulin resistance (IR) and progressive loss of β-cell mass and function are key features of T2D etiology. Obesity is a leading pathogenic factor for developing IR. The aim of the present study was to determine whether sulforaphane (SFN), a natural compound derived from cruciferous vegetables, can prevent (prevention approach) or treat (treatment approach) obesity and IR in mouse models. We show that dietary intake of SFN (0.5 g/kg of HFD) for 20 weeks suppressed high-fat diet (HFD)-induced fat accumulation by 6.04% and improved insulin sensitivity by 23.66% in young male mice. Similarly, dietary provision of SFN (0.25 g/kg) significantly improved blood lipid profile, glucose tolerance, and insulin sensitivity of the middle-aged male mice while it had little effects on body composition as compared with the HFD group. In the treatment study, oral administration of SFN (40 mg/kg) induced weight loss and improved insulin sensitivity and plasma lipid profile in the diet-induced-obesity (DIO) male mice. In all three studies, the metabolic effects of SFN administration were not associated with changes in food intake. In vitro, SFN increased glucose uptake in C2C12 myotubes and increased fatty acid and pyruvate oxidation in primary human skeletal muscle cells. Our results suggest that SFN may be a naturally occurring insulin-sensitizing agent that is capable of improving the metabolic processes in HFD-induced obesity and IR and thereby may be a promising compound for T2D prevention.

A mechanistic overview of sulforaphane and its derivatives application in diabetes and its complications

Sulforaphane (SFN) is a type of phytochemical found in many cruciferous vegetables that has been shown to positively benefit the control of Type 2 Diabetes Mellitus (T2DM). The search was done from 2000 until December 2022 using PubMed, Scopus, Web of Sciences, and Google Scholar databases. We included all in vitro, in vivo, and clinical trials. Sulforaphane has been demonstrated to activate the PI3K/AKT and AMP-activated protein kinase pathways and the glucose transporter type 4 to increase insulin production and reduce insulin resistance. Interestingly, SFN possesses protective effects against diabetes complications, such as diabetic-induced hepatic damage, vascular inflammation and endothelial dysfunction, nephropathy, and neuropathy via nuclear factor erythroid 2-related factor 2 activation that leads to the translation of several anti-oxidant enzymes and regulation glycolysis, pentose phosphate pathway, fatty acid metabolism, glutamine metabolism, and glutathione metabolism. Furthermore, multiple clinical trial studies emphasized the ameliorating effects of SFN on T2DM patients. This review provides sufficient evidence for further research and development of sulforaphane as a hypoglycemic drug.

Sulforaphane: A nutraceutical against diabetes-related complications

There is an increasing interest in the use of nutraceuticals and plant-derived bioactive compounds from foods for their potential health benefits. For example, as a major active ingredient found from cruciferous vegetables like broccoli, there has been growing interest in understanding the therapeutic effects of sulforaphane against diverse metabolic complications. The past decade has seen an extensive growth in literature reporting on the potential health benefits of sulforaphane to neutralize pathological consequences of oxidative stress and inflammation, which may be essential in protecting against diabetes-related complications. In fact, preclinical evidence summarized within this review supports an active role of sulforaphane in activating nuclear factor erythroid 2-related factor 2 or effectively modulating AMP-activated protein kinase to protect against diabetic complications, including diabetic cardiomyopathy, diabetic neuropathy, diabetic nephropathy, as well as other metabolic complications involving non-alcoholic fatty liver disease and skeletal muscle insulin resistance. With clinical evidence suggesting that foods rich in sulforaphane like broccoli can improve the metabolic status and lower cardiovascular disease risk by reducing biomarkers of oxidative stress and inflammation in patients with type 2 diabetes. This information remains essential in determining the therapeutic value of sulforaphane or its potential use as a nutraceutical to manage diabetes and its related complications. Finally, this review discusses essential information on the bioavailability profile of sulforaphane, while also covering information on the pathological consequences of oxidative stress and inflammation that drive the development and progression of diabetes.

Therapeutic potential of sulforaphane in liver diseases: a review

The burden of liver diseases such as metabolic-associated fatty liver diseases and hepatocellular carcinoma has increased rapidly worldwide over the past decades. However, pharmacological therapies for these liver diseases are insufficient. Sulforaphane (SFN), an isothiocyanate that is mainly found in cruciferous vegetables, has been found to have a broad spectrum of activities like antioxidation, anti-inflammation, anti-diabetic, and anticancer effects. Recently, a growing number of studies have reported that SFN could significantly ameliorate hepatic steatosis and prevent the development of fatty liver, improve insulin sensitivity, attenuate oxidative damage and liver injury, induce apoptosis, and inhibit the proliferation of hepatoma cells through multiple signaling pathways. Moreover, many clinical studies have demonstrated that SFN is harmless to the human body and well-tolerated by individuals. This emerging evidence suggests SFN to be a promising drug candidate in the treatment of liver diseases. Nevertheless, limitations exist in the development of SFN as a hepatoprotective drug due to its special properties, including instability, water insolubility, and high inter-individual variation of bioavailability when used from broccoli sprout extracts. Herein, we comprehensively review the recent progress of SFN in the treatment of common liver diseases and the underlying mechanisms, with the aim to provide a better understanding of the therapeutic potential of SFN in liver diseases.

Endothelial dysfunction, platelet hyperactivity, hypertension, and the metabolic syndrome: molecular insights and combating strategies

Metabolic syndrome (MetS) is a multifaceted condition that increases the possibility of developing atherosclerotic cardiovascular disease. MetS includes obesity, hypertension, dyslipidemia, hyperglycemia, endothelial dysfunction, and platelet hyperactivity. There is a concerning rise in the occurrence and frequency of MetS globally. The rising incidence and severity of MetS need a proactive, multipronged strategy for identifying and treating those affected. For many MetS patients, achieving recommended goals for healthy fat intake, blood pressure control, and blood glucose management may require a combination of medicine therapy, lifestyles, nutraceuticals, and others. However, it is essential to note that lifestyle modification should be the first-line therapy for MetS. In addition, MetS requires pharmacological, nutraceutical, or other interventions. This review aimed to bring together the etiology, molecular mechanisms, and dietary strategies to combat hypertension, endothelial dysfunction, and platelet dysfunction in individuals with MetS.

Sulforaphane exhibits potent renoprotective effects in preclinical models of kidney diseases: A systematic review and meta-analysis

AIMS

Sulforaphane (SFN), a naturally occurring isothiocyanate found in cruciferous vegetables, has received extensive attention as a natural activator of the Nrf2/Keap1 cytoprotective pathway. In this review, a meta-analysis and systematic review of the renoprotective effects of SFN were performed in various preclinical models of kidney diseases.

MAIN METHODS

The primary outcome was the impact of SFN on renal function biomarkers (uremia, creatininemia, proteinuria or creatinine clearance) and secondary outcomes were kidney lesion histological indices/kidney injury molecular biomarkers. The effects of SFN were evaluated according to the standardized mean differences (SMDs). A random-effects model was applied to estimate the overall summary effect.

KEY FINDINGS

Twenty-five articles (out of 209 studies) were selected from the literature. SFN administration significantly increased creatinine clearance (SMD +1.88 95 % CI: [1.09; 2.68], P < 0.0001, I² = 0 %) and decreased the plasma creatinine (SMD -1.24, [-1.59; -0.88], P < 0.0001, I² = 36.0 %) and urea (SMD -3.22 [-4.42, -2.01], P < 0.0001, I² = 72.4 %) levels. SFN administration (median dose: 2.5 mg/kg, median duration: 3 weeks) significantly decreased urinary protein excretion (SMD -2.20 [-2.68; -1.73], P < 0.0001, I² = 34.1 %). It further improved two kidney lesion histological indices namely kidney fibrosis (SMD -3.08 [-4.53; -1.63], P < 0.0001, I² = 73.7 %) and glomerulosclerosis (SMD -2.24 [-2.96; -1.53], P < 0.0001, I² = 9.7 %) and decreased kidney injury molecular biomarkers (SMD -1.51 [-2.00; -1.02], P < 0.0001, I² = 0 %).

SIGNIFICANCE

These findings provide new insights concerning preclinical strategies for treating kidney disease or kidney failure with SFN supplements and should stimulate interest in clinical evaluations of SFN in patients with kidney disease.

Sulforaphane: A review of its therapeutic potentials, advances in its nanodelivery, recent patents, and clinical trials

Traditionally, herbal supplements have shown an exceptional potential of desirability for the prevention of diseases and their treatment. Sulforaphane (SFN), an organosulfur compound belongs to the isothiocyanate (ITC) group and is mainly found naturally in cruciferous vegetables. Several studies have now revealed that SFN possesses broad spectrum of activities and has shown extraordinary potential as antioxidant, antitumor, anti-angiogenic, and anti-inflammatory agent. In addition, SFN is proven to be less toxic, non-oxidizable, and its administration to individuals is well tolerated, making it an effective natural dietary supplement for clinical trials. SFN has shown its ability to be a promising future drug molecule for the management of various diseases mainly due to its potent antioxidant properties. In recent times, several newer drug delivery systems were designed and developed for this potential molecule in order to enhance its bioavailability, stability, and to reduce its side effects. This review focuses to cover numerous data supporting the wide range of pharmacological activities of SFN, its drug-related issues, and approaches to improve its physicochemical and biological properties, including solubility, stability, and bioavailability. Recent patents and the ongoing clinical trials on SFN are also summarized.

Sulforaphane response on aluminum-induced oxidative stress, alterations in sperm characterization and testicular histomorphometry in Wistar rats

Background

The exposure of male individual to environmental toxicant is regarded as a channel that results in reduced sperm counts and infertility.

Objective

This study investigated the ameliorative response of Sulforaphane (SFN) on Aluminum trichloride (AlCl3) induced testicular toxicity in adult male Wistar rats.

Materials and Methods

A total of 32 adult male Wistar rats (180-200 gm between 8-10 wk) were divided into four groups (n = 8/each). Group A) received distilled water orally as placebo; Group B) received 100 mg/kgbw AlCl3 only orally; Group C) received 100 mg/kgbw AlCl3 and 100 mg/kgbw SFN orally; and Group D) received 100 mg/kgbw SFN only orally. After 28 days of experiment, animals underwent cervical dislocation, blood serum was obtained for analysis, and testes were harvested for biochemical assays, histology, hormonal profile, and sperm characterization.

Results

The sperm parameters showed a significant difference within the AlCl3 only group compared with the control and SFN only groups (p = 0.02). However, AlCl3 and SFN co-treatment showed improvement in the motility, viability, and sperm count compared with the AlCl3 only group (p = 0.02). Furthermore, there was a significant decline in the levels of hormones profile and antioxidant status in AlCl3 only group compared to the control and SFN only (p = 0.02). The testicular histoarchitecture of the AlCl3 only group showed shrinkage of seminiferous tubules, spermatogenesis disruption, and empty lumen compared to the control and SFN only groups.

Conclusion

The present study revealed the ameliorative response of SFN on AlCl3-induced testicular toxicity on serum hormone profiles, antioxidant status, lipid peroxidation, and histomorphometric analysis through oxidative stress.

Sulforaphane improves voiding function via the preserving mitochondrial function in diabetic rats

BACKGROUND

Hyperglycemia evoked oxidative stress contributing to diabetes (DM)-induced voiding dysfunction. We explored whether antioxidant sulforaphane,a NF-E2-related nuclear factor erythroid-2 (Nrf-2) activator, may ameliorate DM-induced bladder dysfunction.

METHODS

DM was induced by streptozotocin and sulforaphanewas administered before DM induction.Bladder reactive oxygen species (ROS) were determined by an ultrasensitive chemiluminescence analyzer. Mitochondrial function index mitochondrial Bax and cytosolic cytochrome c, antioxidant defense Nrf-2/HO-1, endoplasmic reticulum stress marker ATF-6/CHOP, and caspase 3/PARP were evaluated by Western blot.

RESULTS

DM increased Keap1 and reduced Nrf-2 expression, associated with increase of bladder ROS, mitochondrial Bax translocation, cytosolic cytochrome c release, ATF-6/CHOP, caspase-3/PARP in bladders which resulted in voiding dysfunction by increased intercontraction intervals and micturition duration. However, sulforaphanesignificantly increased nuclear Nrf-2/HO-1axis expression, decreased bladder ROS amount, mitochondrial Bax translocation, cytochrome c release, ATF-6/CHOP and caspase 3/PARP/apoptosis, thereby improved the voiding function by the shortened intercontraction intervals and micturition duration.

CONCLUSION

We suggest that sulforaphanevia activating Nrf-2/HO-1 signaling preserved mitochondrial function and suppressed DM-induced ROS, endoplasmic reticulum stress, apoptosis and voiding dysfunction.

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.

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.

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.

Concerted redox modulation by sulforaphane alleviates diabetes and cardiometabolic syndrome

Diabetes and cardiometabolic disorders such as hypertension and obesity are major risk factors for the development of cardiovascular disease, with a wealth of evidence suggesting that oxidative stress is linked to the initiation and pathogenesis of these disease processes. With yearly increases in the global incidence of cardiovascular diseases (CVD) and diabetes, numerous studies have focused on characterizing whether upregulating antioxidant defenses through exogenous antioxidants (e.g. vitamin E, vitamin C) or activation of endogenous defenses (e.g. the Nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant defense pathway) may be of benefit. The dietary isothiocyanate sulforaphane (SFN) is currently the subject of several clinical trials for a variety of disease states, including the evaluation of its therapeutic potential to ameliorate diabetic and cardiometabolic complications. SFN is a well characterized and potent Nrf2 inducer, however recent studies suggest its protective actions may be in part mediated by its modulation of various pro-inflammatory (e.g. Nuclear factor-kappa B (NFκB)) and metabolic (e.g. Peroxisome Proliferator-Activator Receptor Gamma (PPARγ)) signaling pathways. The focus of this review is to provide a detailed analysis of the known mechanisms by which SFN modulates Nrf2, NFκB and PPARγ signaling and crosstalk and to provide a critical evaluation of the evidence linking these transcriptional pathways with diabetic and cardiometabolic complications and SFN mediated cytoprotection. To allow comparison between rodent and human studies, we discuss the published bioavailability of SFN metabolites achieved in rodents and man in the context of Nrf2, NFκB and PPARγ signaling. Furthermore, we provide an update on the functional outcomes and implicated signaling pathways reported in recent clinical trials with SFN in Type 2 diabetic patients.

Sulforaphane ameliorates glucose intolerance in obese mice via the upregulation of the insulin signaling pathway

Sulforaphane (SFN) is a dietary component with multiple bioactivities; however, its role in obesity-related metabolic derangement remains unclear.

The Sulforaphane and pyridoxamine supplementation normalize endothelial dysfunction associated with type 2 diabetes

In this study we investigate pyridoxamine (PM) and/or sulforaphane (SFN) as therapeutic interventions to determine whether activators of NFE2-related factor 2 (Nrf2) can be used in addition with inhibitors of advanced glycation end products (AGE) formation to attenuate oxidative stress and improve endothelial dysfunction in type 2 diabetes. Goto-kakizaki (GK) rats, an animal model of non-obese type 2 diabetes, were treated with or without PM and/or SFN during 8 weeks and compared with age-matched Wistar rats. At the end of the treatment, nitric oxide (NO)-dependent and independent vasorelaxation in isolated aorta and mesenteric arteries were evaluated. Metabolic profile, NO bioavailability and vascular oxidative stress, AGE and Nrf2 levels were also assessed. Diabetic GK rats presented significantly lower levels of Nrf2 and concomitantly exhibited higher levels of oxidative stress and endothelial dysfunction. PM and SFN as monotherapy were capable of significantly improving endothelial dysfunction in aorta and mesenteric arteries decreasing vascular oxidative damage, AGE and HbA1c levels. Furthermore, SFN + PM proved more effective reducing systemic free fatty acids levels, normalizing endothelial function, NO bioavailability and glycation in GK rats. Activators of Nrf2 can be used therapeutically in association with inhibitors of AGE and cross-linking formation to normalize endothelial dysfunction in type 2 diabetes.

Metabolic syndrome: pathophysiology, management, and modulation by natural compounds

Metabolic syndrome (MetS) represents a cluster of metabolic abnormalities that include hypertension, central obesity, insulin resistance, and atherogenic dyslipidemia, and is strongly associated with an increased risk for developing diabetes and atherosclerotic and nonatherosclerotic cardiovascular disease (CVD). The pathogenesis of MetS involves both genetic and acquired factors that contribute to the final pathway of inflammation that leads to CVD. MetS has gained significant importance recently due to the exponential increase in obesity worldwide. Early diagnosis is important in order to employ lifestyle and risk factor modification. Here, we review the epidemiology and pathogenesis of MetS, the role of inflammation in MetS, and summarize existing natural therapies for MetS.

Sulforaphane ameliorates the insulin responsiveness and the lipid profile but does not alter the antioxidant response in diabetic rats

Diabetes is one of the most prevalent chronic non-communicable diseases and is characterized by hyperglycemia and increased oxidative stress. These two alterations are also responsible for the main diabetic complications: cardiovascular disease, retinopathy, nephropathy and peripheral neuropathy. Diabetes progression is governed by pancreatic β-cell failure, and recent studies showed that sulforaphane (SFN) might be able to prevent this change, preserving insulin production. Consequently, our goal was to test the effects of SFN on metabolic parameters related to diabetic complications and antioxidant defenses (superoxide dismutase, catalase and sulfhydryl groups) in the pancreas, liver and kidney of non-diabetic and diabetic rats. Male Wistar rats were treated with water or 0.5 mg kg(-1) SFN i.p. for 21 days after diabetes induction. In diabetic animals treated with SFN, the serum levels of total cholesterol, non-HDL cholesterol and triacylglycerols were similar to those of non-diabetic animals, and the insulin responsiveness was higher than that of the diabetic animals that did not receive the compound. No effect of SFN on the superoxide dismutase and catalase activity or sulfhydryl groups was observed in the pancreas, liver or kidney of the treated animals. We conclude that SFN ameliorates some features of clinical diabetic complications particularly the lipid profile and insulin responsiveness, but it does not modulate the antioxidant response induced by superoxide dismutase, catalase and sulfhydryl groups in the evaluated organs.

Protective role of sulphoraphane against vascular complications in diabetes

Context Diabetes is a global health challenge. Although large prospective clinical trials have shown that intensive control of blood glucose or blood pressure reduces the risk for development and progression of vascular complications in diabetes, a substantial number of diabetic patients still experience renal failure and cardiovascular events, which could account for disabilities and high mortality rate in these subjects. Objective Sulphoraphane is a naturally occurring isothiocyanate found in widely consumed cruciferous vegetables, such as broccoli, cabbage and Brussels sprouts, and an inducer of phase II antioxidant and detoxification enzymes with anticancer properties. We reviewed here the protective role of sulphoraphane against diabetic vascular complications. Methods In this review, literature searches were undertaken in Medline and in CrossRef. Non-English language articles were excluded. Keywords [sulphoraphane and (diabetes, diabetic nephropathy, diabetic retinopathy, diabetic neuropathy, diabetic complications, vascular, cardiomyocytes, heart or glycation)] have been used to select the articles. Results There is accumulating evidence that sulphoraphane exerts beneficial effects on vascular damage in both cell culture and diabetic animal models via antioxidative properties. Furthermore, we have recently found that sulphoraphane inhibits in vitro formation of advanced glycation end products (AGEs), suppresses the AGE-induced inflammatory reactions in rat aorta by reducing receptor for AGEs (RAGE) expression and decreases serum levels of AGEs in humans. Conclusion These findings suggest that blockade of oxidative stress and/or the AGE-RAGE axis by sulphoraphane may be a novel therapeutic strategy for preventing vascular complications in diabetes.

LPS-induced expression of CD14 in the TRIF pathway is epigenetically regulated by sulforaphane in porcine pulmonary alveolar macrophages

Pulmonary alveolar macrophages (AMs) are important in defense against bacterial lung inflammation. Cluster of differentiation 14 (CD14) is involved in recognizing bacterial lipopolysaccharide (LPS) through MyD88-dependent and TRIF pathways of innate immunity. Sulforaphane (SFN) shows anti-inflammatory activity and suppresses DNA methylation. To identify CD14 epigenetic changes by SFN in the LPS-induced TRIF pathway, an AMs model was investigated in vitro. CD14 gene expression was induced by 5 µg/ml LPS at the time point of 12 h and suppressed by 5 µM SFN. After 12 h of LPS stimulation, gene expression was significantly up-regulated, including TRIF, TRAF6, NF-κB, TRAF3, IRF7, TNF-α, IL-1β, IL-6, and IFN-β. LPS-induced TRAM, TRIF, RIPK1, TRAF3, TNF-α, IL-1β and IFN-β were suppressed by 5 µM SFN. Similarly, DNMT3a expression was increased by LPS but significantly down-regulated by 5 µM SFN. It showed positive correlation of CD14 gene body methylation with in LPS-stimulated AMs, and this methylation status was inhibited by SFN. This study suggests that SFN suppresses CD14 activation in bacterial inflammation through epigenetic regulation of CD14 gene body methylation associated with DNMT3a. The results provide insights into SFN-mediated epigenetic down-regulation of CD14 in LPS-induced TRIF pathway inflammation and may lead to new methods for controlling LPS-induced inflammation in pigs.

Broccoli sprout extract prevents diabetic cardiomyopathy via Nrf2 activation in db/db T2DM mice

To develop a clinic-relevant protocol for systemic up-regulation of NFE2-related factor 2 (Nrf2) to prevent diabetic cardiomyopathy (DCM), male db/db and age-matched wild-type (WT) mice were given sulforaphane (SFN, an Nrf2 activator) and its natural source, broccoli sprout extract (BSE) by gavage every other day for 3 months, with four groups: vehicle (0.1 ml/10 g), BSE-low dose (estimated SFN availability at 0.5 mg/kg), BSE-high dose (estimated SFN availability at 1.0 mg/kg), and SFN (0.5 mg/kg). Cardiac function and pathological changes (hypertrophy, fibrosis, inflammation and oxidative damage) were assessed by echocardiography and histopathological examination along with Western blot and real-time PCR, respectively. Both BSE and SFN significantly prevented diabetes-induced cardiac dysfunction, hypertrophy and fibrosis. Mechanistically, BSE, like SFN, significantly up-regulated Nrf2 transcriptional activity, evidenced by the increased Nrf2 nuclear accumulation and its downstream gene expression. This resulted in a significant prevention of cardiac oxidative damage and inflammation. For all these preventive effects, BSE at high dose provided a similar effect as did SFN. These results indicated that BSE at high dose prevents DCM in a manner congruent with SFN treatment. Therefore, it suggests that BSE could potentially be used as a natural and safe treatment against DCM via Nrf2 activation.

Effect of a trans fatty acid-enriched diet on biochemical and inflammatory parameters in Wistar rats

PURPOSE

Recent data regarding trans fatty acids (TFAs) have implicated these lipids as particularly deleterious to human health, causing systemic inflammation, endothelial dysfunction and possibly inflammation in the central nervous system (CNS). We aimed to clarify the impact of partially hydrogenated soybean oil (PHSO) with different TFA concentrations on cerebrospinal fluid (CSF), serum and hepatic parameters in adult Wistar rats.

METHODS

Wistar rats (n = 15/group) were fed either a normolipidic diet or a hyperlipidic diet for 90 days. The normolipidic and hyperlipidic diets had the same ingredients except for fat compositions, concentrations and calories. We used lard in the cis fatty acid group and PHSO in the trans fatty acid group. The intervention groups were as follows: (1) low lard (LL), (2) high lard (HL), (3) low partially hydrogenated soybean oil (LPHSO) and (4) high partially hydrogenated soybean oil (HPHSO). Body weight, lipid profiles and the inflammatory responses in the CSF, serum and liver tissue were analyzed.

RESULTS

Surprisingly, with the PHSO diet we observed a worse metabolic response that was associated with oxidative stress in hepatic tissue as well as impaired serum and CSF fluid parameters at both PHSO concentrations. In many analyses, there were no significant differences between the LPHSO and HPHSO diets.

CONCLUSIONS

Dietary supplementation with PHSO impaired inflammatory parameters in CSF and blood, induced insulin resistance, altered lipid profiles and caused hepatic damage. Overall, these findings suggest that fat composition is more important than the quantity of fat consumed in terms of cis and trans fatty acid diets.

Sulforaphane Protects against Cardiovascular Disease via Nrf2 Activation

Cardiovascular disease (CVD) causes an unparalleled proportion of the global burden of disease and will remain the main cause of mortality for the near future. Oxidative stress plays a major role in the pathophysiology of cardiac disorders. Several studies have highlighted the cardinal role played by the overproduction of reactive oxygen or nitrogen species in the pathogenesis of ischemic myocardial damage and consequent cardiac dysfunction. Isothiocyanates (ITC) are sulfur-containing compounds that are broadly distributed among cruciferous vegetables. Sulforaphane (SFN) is an ITC shown to possess anticancer activities by both in vivo and epidemiological studies. Recent data have indicated that the beneficial effects of SFN in CVD are due to its antioxidant and anti-inflammatory properties. SFN activates NF-E2-related factor 2 (Nrf2), a basic leucine zipper transcription factor that serves as a defense mechanism against oxidative stress and electrophilic toxicants by inducing more than a hundred cytoprotective proteins, including antioxidants and phase II detoxifying enzymes. This review will summarize the evidence from clinical studies and animal experiments relating to the potential mechanisms by which SFN modulates Nrf2 activation and protects against CVD.

Sulforaphane Attenuates Muscle Inflammation in Dystrophin-deficient mdx Mice via NF-E2-related Factor 2 (Nrf2)-mediated Inhibition of NF-κB Signaling Pathway

Inflammation is widely distributed in patients with Duchenne muscular dystrophy and ultimately leads to progressive deterioration of muscle function with chronic muscle damage, oxidative stress, and reduced oxidative capacity. NF-E2-related factor 2 (Nrf2) plays a critical role in defending against inflammation in different tissues via activation of phase II enzyme heme oxygenase-1 and inhibition of the NF-κB signaling pathway. However, the role of Nrf2 in the inflammation of dystrophic muscle remains unknown. To determine whether Nrf2 may counteract inflammation in dystrophic muscle, we treated 4-week-old male mdx mice with the Nrf2 activator sulforaphane (SFN) by gavage (2 mg/kg of body weight/day) for 4 weeks. The experimental results demonstrated that SFN treatment increased the expression of muscle phase II enzyme heme oxygenase-1 in an Nrf2-dependent manner. Inflammation in mice was reduced by SFN treatment as indicated by decreased infiltration of immune cells and expression of the inflammatory cytokine CD45 and proinflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 in the skeletal muscles of mdx mice. In addition, SFN treatment also decreased the expression of NF-κB(p65) and phosphorylated IκB kinase-α as well as increased inhibitor of κB-α expression in mdx mice in an Nrf2-dependent manner. Collectively, these results show that SFN-induced Nrf2 can alleviate muscle inflammation in mdx mice by inhibiting the NF-κB signaling pathway.

Sulforaphane attenuation of experimental diabetic nephropathy involves GSK-3 beta/Fyn/Nrf2 signaling pathway

Sulforaphane (SFN), the bioactive component of cruciferous vegetables, is a potent indirect antioxidant. Oxidative stress and activation of glycogen synthase kinase 3beta (GSK3β) are two major contributors to the pathogenesis of diabetic nephropathy (DN). Here, we investigated whether and how SFN affected GSK3β in experimental models of DN in vivo and in vitro. SFN treatment obviously prevented the increase in urine albumin excretion, matrix expansion, transforming growth factor-β1 expression, fibronectin and type IV collagen deposition in the diabetic kidney. Simultaneously, the level of 8-oxo-deoxyguanosine, an indicator of oxidative damage, was markedly lowered in SFN-treated diabetic rats, together with a significant reduction in activity of the GSK-3β/Fyn axis and an evident activation of Nrf2 signaling. Similarly, antifibrotic effects of SFN, parallel to enhanced inhibitory Ser9-phosphorylation of GSK3β and Fyn/Nrf2 nuclear export/import, were observed in the cultured rat mesangial cells (RMC) exposed to high glucose. The salutary effects of SFN on high-glucose-stimulated RMC were abolished by overexpression of GSK3β while being rescued by lithium chloride, a well-known GSK3β inhibitor. Taken together, our findings suggested that SFN ameliorated experimental diabetic nephropathy, at least in part, via GSK3β/Fyn/Nrf2 signaling pathway.

Sulforaphane alleviates muscular dystrophy in mdx mice by activation of Nrf2

Sulforaphane (SFN), one of the most important isothiocyanates in the human diet, is known to have chemo-preventive and antioxidant activities in different tissues via activation of nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated induction of antioxidant/phase II enzymes, such as heme oxygenase-1 and NAD(P)H quinone oxidoreductase 1. However, its effects on muscular dystrophy remain unknown. This work was undertaken to evaluate the effects of SFN on Duchenne muscular dystrophy. Four-week-old mdx mice were treated with SFN by gavage (2 mg·kg body wt(-1)·day(-1) for 8 wk), and our results demonstrated that SFN treatment increased the expression and activity of muscle phase II enzymes NAD(P)H quinone oxidoreductase 1 and heme oxygenase-1 with a Nrf2-dependent manner. SFN significantly increased skeletal muscle mass, muscle force (∼30%), running distance (∼20%), and GSH-to-GSSG ratio (∼3.2-fold) of mdx mice and decreased the activities of plasma creatine phosphokinase (∼45%) and lactate dehydrogenase (∼40%), gastrocnemius hypertrophy (∼25%), myocardial hypertrophy (∼20%), and malondialdehyde levels (∼60%). Furthermore, SFN treatment also reduced the central nucleation (∼40%), fiber size variability, and inflammation and improved the sarcolemmal integrity of mdx mice. Collectively, these results show that SFN can improve muscle function and pathology and protect dystrophic muscle from oxidative damage in mdx mice associated with Nrf2 signaling pathway, which indicate Nrf2 may have clinical implications for the treatment of patients with muscular dystrophy.

Correlation between type 1 diabetic nephropathy and insulin resistance

AIM: To perform a quantitative test for urinary protein and different renal function indexes and explore the expression and phosphorylation of relevant proteins in the insulin signal pathway.

METHODS: Controls and cases at a ratio of 1:1 were included in this prospective randomized controlled clinical study. There were 40 patients with diabetic nephropathy (DN) and 40 normal cases with comparable age. Plasma samples were collected from the subjects to detect the protein expression of insulin receptor substrate (IRS)-2, p-IRS-2, AKT, and p-AKT by Western blot. The correlations of the quantity of urinary protein, RBF and GFR with homeostasis model assessment-insulin resistance (HOMA-IR), homeostasis model assessment-insulin sensitive index (HOMA-ISI) and homeostasis model assessment-pancreatic beta-cell function (HOMA-β%) were analyzed.

RESULTS: The ratios of p-IRS-2/IRS-2 and p-AKT/AKT decreased significantly in the DN group compared with the normal group (P < 0.05). There was a positive correlation between the quantity of urinary protein and HOMA-IR (P < 0.05) and a negative correlation between the quantity of urinary protein and HOMA-ISI (P < 0.05).

CONCLUSION: The ratios of p-IRS-2/IRS-2 and p-AKT/AKT decrease in DN patients. There exist correlations between the quantity of urinary protein and HOMA-IR and HOMA-ISI. These results indicate that the decrease of HOMA-ISI, the increase of HOMA-IR and the blockage of the insulin signal pathway may be key factors that cause DN.

Sulforaphane reduces vascular inflammation in mice and prevents TNF-α-induced monocyte adhesion to primary endothelial cells through interfering with the NF-κB pathway

Sulforaphane, a naturally occurring isothiocyanate present in cruciferous vegetables, has received wide attention for its potential to improve vascular function in vitro. However, its effect in vivo and the molecular mechanism of sulforaphane at physiological concentrations remain unclear. Here, we report that a sulforaphane concentration as low as 0.5 μM significantly inhibited tumor necrosis factor-α (TNF-α)-induced adhesion of monocytes to human umbilical vein endothelial cells, a key event in the pathogenesis of atherosclerosis both in static and under flow conditions. Such physiological concentrations of sulforaphane also significantly suppressed TNF-α-induced production of monocyte chemotactic protein-1 and adhesion molecules including soluble vascular adhesion molecule-1 and soluble E-selectin, key mediators in the regulation of enhanced endothelial cell-monocyte interaction. Furthermore, sulforaphane inhibited TNF-α-induced nuclear factor (NF)-κB transcriptional activity, Inhibitor of NF-κB alpha (IκBα) degradation and subsequent NF-κB p65 nuclear translocation in endothelial cells, suggesting that sulforaphane can inhibit inflammation by suppressing NF-κB signaling. In an animal study, sulforaphane (300 ppm) in a mouse diet significantly abolished TNF-α-increased ex vivo monocyte adhesion and circulating adhesion molecules and chemokines in C57BL/6 mice. Histology showed that sulforaphane treatment significantly prevented the eruption of endothelial lining in the intima layer of the aorta and preserved elastin fibers' delicate organization, as shown by Verhoeff-van Gieson staining. Immunohistochemistry studies showed that sulforaphane treatment also reduced vascular adhesion molecule-1 and monocyte-derived F4/80-positive macrophages in the aorta of TNF-α-treated mice. In conclusion, sulforaphane at physiological concentrations protects against TNF-α-induced vascular endothelial inflammation, in both in vitro and in vivo models. This anti-inflammatory effect of sulforaphane may be, at least in part, associated with interfering with the NF-κB pathway.