Sulforaphane reduces intracellular survival of Staphylococcus aureus in macrophages through inhibition of JNK and p38 MAPK‑induced inflammation

Protective role of sulforaphane in lipid metabolism-related diseases

Sulforaphane (SFN) is a phytochemical bioactive substance commonly found in cruciferous plants, such as broccoli and mustard. It has been reported to possess antibacterial, anti-inflammatory, anti-oxidant, anti-cancer and autophagy regulating properties. Recent studies have revealed that SFN regulates fat metabolism both in vivo and in vitro through various mechanisms, including alleviating endoplasmic reticulum stress, inhibiting inflammatory response and improving mitochondrial dysfunction, involving Nrf2/ARE, NF-κB, NLRP3 inflammasome, HDAC8-PGC1α axis and other signaling pathways. By curbing complications associated with abnormal fat metabolic diseases, SFN exhibits therapeutic effects on conditions like obesity, fatty liver disease, atherosclerosis, type 2 diabetes, etc., with minimal side effects. Therefore, it holds promise as a potential alternative treatment for lipid metabolism-related diseases. Although its extraction method has been matured, the thermal instability and preservation difficulties of SFN limit its clinical promotion. More effective and low-cost methods to improve the stability and production of SFN remain to be further studied. This paper reviews the physiological and biological activities of SFN, and summarizes the protective effects and molecular mechanisms of SFN in diseases related to abnormal lipid metabolism. Additionally, it proposes potential challenges, possible solutions and future research directions in the clinical application of SFN.

Sulforaphane Is Not Only a Food Supplement: It Diminishes the Intracellular Survival and Colonization of Salmonella enterica

Sulforaphane is a main bioactive component in several edible cruciferous vegetables. It acquires several benefits to health in addition to its considered antibacterial and antivirulence activities. Herein, we aimed at evaluating the antivirulence activity of sulforaphane against the worldwide clinically important enteric pathogen Salmonella enterica serovar Typhimurium. The influence of sulforaphane on bacterial adhesion, invasion, biofilm formation, and intracellular replication was assayed. Additionally, the effect of sulforaphane on the type III secretion system (TTSS) in S. enterica was quantified. The outcome of the combination with different antibiotics was assessed, and an in vivo protection assay was conducted to assess the influence on S. enterica pathogenesis. The results showed the significant antibiofilm activity of sulforaphane at subinhibitory effect in addition to its significant reduction in bacterial invasion and intracellular replication inside the host cells. The in vivo findings emphasized the decreased capacity of S. enterica to induce pathogenesis in the presence of sulforaphane. Our finding attributed these antivirulence activities to the interference of sulforaphane with TTSS-type II and the downregulation of its encoding genes. In a nutshell, the edible cruciferous vegetable bioactive sulforaphane is a safe adjunct therapy that can be administrated alongside traditional antibiotics for treating clinically significant enteric pathogens as S. enterica.

Synergistic Inhibition of Breast Carcinoma Cell Proliferation by Quercetin and Sulforaphane via Activation of the ERK/MAPK Pathway

In the contemporary era of drug discovery, herbal treatments have demonstrated an unparalleled ability to produce anticancer drugs. An important part of the therapy of cancer is the use of plants and their by-products via analogues, which alter the tumor microenvironment and several signaling pathways. The objective of the current investigation was to conclude the rate at which the herbal medications quercetin (QT) and sulforaphane (SFN) repressed the growth of breast carcinoma cells in MDA-MB-231 by preventing the ERK/MAPK signaling systems. The cells were assessed for several studies after being subjected to different concentrations (0-70 µM) of QT and SFN (QT + SFN) for duration of 24 h. We investigated the combination that QT + SFN generated cytotoxicity using the MTT assay. The DCFH-DA staining technique was utilized to assess ROS. The protein spectra of survival of cells, cell cycle progression, and apoptosis were evaluated employing flow cytometry and western blotting. The consequences illustrated that the relative cytotoxicity of QT and SFN was roughly 28.74 μM and 39.87 μM for MDA-MB-231 cells, respectively. Following the 24-h incubation period, MDA-MB-231 cells exhibit considerable cytotoxicity when QT and SFN are combined, with IC50 values of 19.48 μM. Moreover, MCF-7 and MDA-MB-231 cells treated with QT and SFN concurrently showed substantial production of ROS and increased apoptotic signals. Consequently, because QT + SFN inhibit the production of ERK/MAPK/JNK/p38-based control of proliferation and cell cycle-regulating proteins, it has been considered a chemotherapeutic medication. To determine the extent to which the co-treatment induces apoptosis, more in vivo study will be required before they can be used commercially.

Sulforaphane as a promising anti-caries agents: inhibitory effects on Streptococcus mutans and caries control in a rat model

Dental caries has been one of the most prevalent diseases globally over the last few decades, threatening human oral and general health. The most critical aspect in caries control is to inhibit the dominant cariogenic bacteria Streptococcus mutans (S. mutans). Sulforaphane (SFN), a compound found in a wide range of cruciferous plants, has demonstrated bacteriostatic activities against various pathogenic bacteria. The objective of the present study was to investigate the effects of SFN on S. mutans though both in vitro and in vivo experiment. The minimum inhibitory concentration (MIC) against S. mutans was determined at 256 μg/mL. The growth of S. mutans and the biofilm formation were inhibited by SFN in a dose-dependent manner through suppressing the synthesis of extracellular polysaccharide (EPS) and acid production, as well as decreasing the acid tolerance. Meanwhile, SFN significantly weakened the cariogenic properties of S. mutans at sub-inhibitory concentrations, which were further illustrated by quantitative real-time PCR (qRT-PCR). Moreover, SFN were found to inhibit quorum sensing (QS) by downregulate comCDE system in S. mutans. Further investigation using a rat caries model displayed a prominent caries control in the SFN-treated group with no observed toxicity. The notable results demonstrated in this study highlight the potential of SFN as a natural substitute for current anti-caries agents, while also providing valuable insights into the potential applications of SFN in caries control.

Bioactive sulforaphane from cruciferous vegetables: advances in biosynthesis, metabolism, bioavailability, delivery, health benefits, and applications

Chronic inflammation-induced diseases (CID) are the dominant cause of death worldwide, contributing to over half of all global deaths. Sulforaphane (SFN) derived from cruciferous vegetables has been extensively studied for its multiple functional benefits in alleviating CID. This work comprehensively reviewed the biosynthesis, metabolism, bioavailability, delivery, health benefits, and applications of SFN and its potential mechanisms against CID (e.g., cancer, obesity, type 2 diabetes, et al.), and neurological disorders based on a decade of research. SFN exerts its biological functions through the hydrolysis of glucosinolates by gut microbiota, and exhibits rapid metabolism and excretion characteristics via metabolization of mercapturic acid pathway. Microencapsulation is an important way to improve the stability and targeted delivery of SFN. The health benefits of SNF against CID are attributed to the multiple regulatory mechanisms including modulating oxidative stress, inflammation, apoptosis, immune response, and intestinal homeostasis. The clinical applications of SFN and related formulations show promising potential; however, further exploration is required regarding the sources, dosages, toxicity profiles, and stability of SFN. Together, SFN is a natural product with great potential for development and application, which is crucial for the development of functional food and pharmaceutical industries.

Investigating Sulforaphane's anti-virulence and anti-quorum sensing properties against Pseudomonas aeruginosa

Background

P. aeruginosa, a significant bacterium, can cause severe illness and resistance to antibiotics. Quorum sensing (QS) systems regulate virulence factors production. Targeting QS could reduce bacteria pathogenicity and prevent antibiotic resistance. Cruciferous vegetables contain sulforaphane, known for its anti-inflammatory, antioxidant, anticancer, and antimicrobial properties.

Aim

We aimed to examine the inhibitory influences of sulforaphane, at a sub-inhibitory concentration (¼ minimum inhibitory concentration, MIC), on virulence and QS in P. aeruginosa.

Materials and methods

The sulforaphane's anti-virulence actions at sub-inhibitory concentrations were explored in vitro and in vivo. A sub-MIC concentration of sulforaphane was combined with anti-pseudomonal drugs, and the results of this combination were assessed. The virtual affinity of sulforaphane for the receptors of QS was studied, and its effect on the expression of QS genes was quantified.

Results

Sulforaphane significantly decreased the biofilm formation, motility, ability to withstand oxidative stress, and the synthesis of virulence extracellular enzymes such as proteases, hemolysins, and elastase, as well as other virulence factors like pyocyanin. In addition, sulforaphane lessened the severity of P. aeruginosa infection in mice. Sulforaphane reduced the antipseudomonal antibiotics' MICs when used together, resulting in synergistic effects. The observed anti-virulence impacts were attributed to the ability of sulforaphane to inhibit QS via suppressing the QS genes' expression.

Conclusion

Sulforaphane shows promise as a potent anti-virulence and anti-QS agent that can be used alongside conventional antimicrobials to manage severe infections effectively. Furthermore, this study paves the way for further investigation of sulforaphane and similar structures as pharmacophores for anti-QS candidates.

Network pharmacology and experimental verification of the mechanism of licochalcone A against Staphylococcus aureus pneumonia

Staphylococcus aureus strains cause the majority of pneumonia cases and are resistant to various antibiotics. Given this background, it is very important to discover novel host-targeted therapies. Licochalcone A (LAA), a natural plant product, has various biological activities, but its primary targets in S. aureus pneumonia remain unclear. Therefore, the purpose of this study was to identify its molecular target against S. aureus pneumonia. Network pharmacology analysis, histological assessment, enzyme-linked immunosorbent assays, and Western blotting were used to confirm the pharmacological effects. Network pharmacology revealed 33 potential targets of LAA and S. aureus pneumonia. Enrichment analysis revealed that these potential genes were enriched in the Toll-like receptor and NOD-like receptor signaling pathways. The results were further verified by experiments in which LAA alleviated histopathological changes, inflammatory infiltrating cells and inflammatory cytokines (TNF, IL-6, and IL-1β) in the serum and bronchoalveolar lavage fluid in vivo. Moreover, LAA treatment effectively reduced the expression levels of NF-κB, p-JNK, p-p38, NLRP3, ASC, caspase 1, IL-1β, and IL-18 in lung tissue. The in vitro experimental results were consistent with the in vivo results. Thus, our findings demonstrated that LAA exerts anti-infective effects on S. aureus-induced lung injury via suppression of the Toll-like receptor and NOD-like receptor signaling pathways, which provides a theoretical basis for understanding the function of LAA against S. aureus pneumonia and implies its potential clinical application.

Sulforaphane Attenuates AOM/DSS-Induced Colorectal Tumorigenesis in Mice via Inhibition of Intestinal Inflammation

Sulforaphane (SFN) is a compound derived from cruciferous plants. It has received considerable attention in recent years due to its effectiveness in cancer prevention and anti-inflammatory properties. The purpose of this study was to evaluate the antitumor potential of sulforaphane on colitis-associated carcinogenesis (CAC) through the establishment of a mouse model with AOM/DSS. First, AOM/DSS and DSS-induced model were established and administered SFN for 10 wk, and then the severity of colitis-associated colon cancer was examined macroscopically and histologically. Subsequently, immune cells and cytokines in the tumor microenvironment (TME) were quantified. Finally, the influence of sulforaphane was also investigated using different colon cell lines. We found that sulforaphane treatment decreased tumor volume, myeloid-derived suppressor cells (MDSC) expansion, the expression of the proinflammatory cytokine IL-1β, and the level of IL-10 in serum. Also, it enhanced the antitumor activities of CD8+ T cells and significantly reduced tumorigenesis as induced by AOM/DSS. SFN also attenuated intestinal inflammation in DSS-induced chronic colitis by reshaping the inflammatory microenvironment. This work demonstrates that sulforaphane suppresses carcinogenesis-associated intestinal inflammation and prevents AOM/DSS-induced intestinal tumorigenesis and progression.

Sulforaphane and bladder cancer: a potential novel antitumor compound

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

Effect of Sulforaphane on cardiac injury induced by sepsis in a mouse model: Role of toll-like receptor 4

As sepsis is associated with a 50% increase in mortality, sepsis-induced cardiomyopathy has become a critical topic. A multidisciplinary approach is required for the diagnosis and treatment of septic cardiomyopathy. This study looked at Sulforaphane, a natural product that aims to evaluate cardiac function after sepsis, and its likely mechanism of action. Twenty-four adult male Swiss albino mice were randomly divided into 4 equal groups (n=6): sham, CLP, vehicle Sulforaphane (the same amount of DMSO injected IP one hour before the CLP), and Sulforaphane group (one hour before the CLP, a 5mg/kg dose of Sulforaphane was injected). Cardiac tissue levels of toll-like receptor 4 (TLR-4), pro-inflammatory mediators, anti-inflammatory markers, oxidative stress markers, apoptosis markers, and serum cardiac damage biomarkers were assessed using ELISA. Statistical analyses, including t-tests and ANOVA tests, were performed with a significance level of 0.05 for normally distributed data. Compared to the sham group, the sepsis group had significantly elevated levels of TLR-4, IL-6, TNF-α, MIF, F2-isoprostane, caspase-3, cTn-I, and CK-MB (p<0.05). In contrast, the Sulforaphane pre-treated group demonstrated significantly lower levels of these markers (p<0.05). Additionally, Bcl-2 levels were significantly reduced (p<0.05) in the Sulforaphane group. Sulforaphane administration also significantly attenuated cardiac tissue injury (p<0.05). The findings suggest that Sulforaphane can decrease heart damage in male mice during CLP-induced polymicrobial sepsis by suppressing TLR-4/NF-kB downstream signal transduction pathways.

Dynamic changes in human THP-1-derived M1-to-M2 macrophage polarization during Thelazia callipaeda MIF induction

Macrophages are innate immune cells with essential roles in the immune response during helminth infection. Particularly, the direction of macrophage polarization could contribute to pathogen trapping and killing as well as tissue repair and the resolution of type 2 inflammation. This study establishes that the recombinant protein of Thelazia callipaeda macrophage migration inhibitory factor (T.cp-MIF) induces THP-1-derived macrophages to undergo M1 to M2 type dynamic polarization, using the methods of flow cytometry, real-time quantitative PCR, differential transcriptomic analysis and western blot. Interestingly, there was an increase in protein and mRNA expression of M1-type proteins and cytokines after the use of PI3K inhibitors, suggesting that the polarization state tends to favor the M1 type after M2 type inhibition. In conclusion, the dynamic polarization mechanism of T.cp-MIF-induced human THP-1-derived macrophages from M1 to M2 type is related to the binding of TLR4. It can first affect the M1 type polarization of macrophages by activating its downstream NF-κB pathway. Activation of the PI3K/Akt pathway and inhibition of NF-κB phosphorylation affects the M2 type polarization of macrophages.

Tea Polyphenols Protect the Mammary Gland of Dairy Cows by Enhancing Antioxidant Capacity and Regulating the TGF-β1/p38/JNK Pathway

Tea polyphenols (TPs) are the main active substances in tea and they have many beneficial effects, such as anti-inflammation, antioxidant, anti-cancer and metabolic regulation effects. The quality of milk is affected by mammary gland diseases and there are substantial economic losses resulting from reduced milk production as a consequence of inflammatory injury of the mammary gland. In this study, transcriptome analysis and molecular biology techniques were used to study the effects of TPs on inflammatory injury of the mammary gland. After intervention with TPs, a total of 2085 differentially expressed genes were identified, including 1189 up-regulated genes and 896 down-regulated genes. GO analysis showed that differentially expressed genes played an important role in proton transmembrane transport, oxidation-reduction reactions and inflammatory response. KEGG enrichment suggested that differential genes were concentrated in the TGF-β pathway and active oxygen metabolism process. Experiments were performed to confirm that TPs increased SOD, CAT, T-AOC and GSH-Px content along with a reduction in MDA. Meanwhile, TPs inhibited the expression of TGF-β1 and reduced the phosphorylation of p38 and JNK. The expression of inflammatory cytokines IL-1β, IL-6 and TNF-α were significantly decreased after intervention with TPs. In summary, all the data indicated that TPs protected the mammary gland by enhancing the antioxidant capacity and down-regulating the TGF-β1/p38/JNK pathway.

Immunomodulatory Effects of (R)-Sulforaphane on LPS-Activated Murine Immune Cells: Molecular Signaling Pathways and Epigenetic Changes in Histone Markers

The aim of this study was to explore the immunomodulatory effects of the natural enantiomer (R)-Sulforaphane (SFN) and the possible signaling pathways involved in an ex vivo model of LPS-stimulated murine peritoneal macrophages. Furthermore, we studied the epigenetic changes induced by (R)-SFN as well as the post-translational modifications of histone H3 (H3K9me3 and H3K18ac) in relation to the production of cytokines in murine splenocytes after LPS stimulation. (R)-SFN was able to modulate the inflammatory response and oxidative stress induced by LPS stimulation in murine peritoneal macrophages through the inhibition of reactive oxygen species (ROS), nitric oxide (NO) and cytokine (IL-1β, IL-6, IL-17, IL-18 and TNF-α) production by down-regulating the expression of pro-inflammatory enzymes (iNOS, COX-2 and mPGES-1). We also found that activation of the Nrf-2/HO-1 axis and inhibition of the JAK2/STAT-3, MAPK, canonical and non-canonical inflammasome signaling pathways could have been responsible for the immunomodulatory effects of (R)-SFN. Furthermore, (R)-SFN modulated epigenetic modifications through histone methylation (H3K9me3) and deacetylation (H3K18ac) in LPS-activated spleen cells. Collectively, our results suggest that (R)-SFN could be a promising epinutraceutical compound for the management of immunoinflammatory diseases.

Arbutin ameliorated ulcerative colitis of mice induced by dextran sodium sulfate (DSS)

Accumulating evidence has revealed the anti-inflammatory effects of arbutin against various diseases. However, the effects of arbutin are not clarified in ulcerative colitis. This study was intended to investigate the protective effects and mechanisms of arbutin on DSS-induced colitis. Hematoxylin eosin staining was performed to determine the pathological damage of intestinal tissue in mice. Inflammatory factors levels in intestinal tissue were detected by enzyme linked immunosorbent assay (ELISA) assay. TUNEL staining showed the apoptosis levels of cells. Intestinal permeability was analyzed using the application of Fluorescein isothiocyanate Dextran (FD) 4. The levels of Zona Occludens 1 (ZO-1), occluding and claudin-1, and the related proteins in MAPK/ELK1 pathway were analyzed by Western blot. DSS promotes pathological injury, the levels of pro-inflammatory factors containing tumor necrosis factor alpha (TNF-α), Interleukin- 6 (IL-6) and myeloperoxidase (MPO), and cell apoptosis in the mouse colon. Additionally, intestinal permeability was increased and the levels of tight function-related proteins were increased following DSS induction. Its effects could be greatly improved by arbutin. Arbutin exerted effects by eliciting anti-inflammatory effects and maintaining normal intestinal mucosal barrier function, the action mechanism of which could be associated with MAPK/ELK1 pathway.

NEK7-Mediated Activation of NLRP3 Inflammasome Is Coordinated by Potassium Efflux/Syk/JNK Signaling During Staphylococcus aureus Infection

Staphylococcus aureus (S. aureus) is a foodborne pathogen that causes severe diseases, such as endocarditis, sepsis, and bacteremia. As an important component of innate immune system, the NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays a critical role in defense against pathogen infection. However, the cellular mechanism of NLRP3 inflammasome activation during S. aureus infection remains unknown. In the present study, we found that spleen tyrosine kinase (Syk) and c-Jun N-terminal kinase (JNK) were rapidly phosphorylated during S. aureus infection. Moreover, a Syk/JNK inhibitor and Syk/JNK siRNA not only reduced NLRP3 inflammasome-associated molecule expression at the protein and mRNA levels, apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) speck formation, and interleukin-1β (IL-1β), and IL-18 release but also rescued the decreased NIMA-related kinase 7 (NEK7) expression level following suppression of the NEK7-NLRP3 interaction in macrophages. Interestingly, Syk/JNK phosphorylation levels and NLRP3 inflammasome-associated molecule expression were decreased by blockade of K⁺ efflux. Furthermore, activation of the NLRP3 inflammasome and a lower NEK7 protein level were found in vivo upon S. aureus infection. Taken together, our data indicated that S. aureus infection induces a K⁺ efflux/Syk/JNK/NEK7-NLRP3 signaling pathway and the subsequent activation of the NLRP3 inflammasome for the release of proinflammatory cytokines. This study expands our understanding of the basic molecular mechanism regulating inflammation and provides potential value for anti-infective drug development against S. aureus infection.

Dietary Isothiocyanates, Sulforaphane and 2-Phenethyl Isothiocyanate, Effectively Impair Vibrio cholerae Virulence

Vibrio cholerae represents a constant threat to public health, causing widespread infections, especially in developing countries with a significant number of fatalities and serious complications every year. The standard treatment by oral rehydration does not eliminate the source of infection, while increasing antibiotic resistance among pathogenic V. cholerae strains makes the therapy difficult. Thus, we assessed the antibacterial potential of plant-derived phytoncides, isothiocyanates (ITC), against V. cholerae O365 strain. Sulforaphane (SFN) and 2-phenethyl isothiocyanate (PEITC) ability to inhibit bacterial growth was assessed. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values indicate that these compounds possess antibacterial activity and are also effective against cells growing in a biofilm. Tested ITC caused accumulation of stringent response alarmone, ppGpp, which indicates induction of the global stress response. It was accompanied by bacterial cytoplasm shrinkage, the inhibition of the DNA, and RNA synthesis as well as downregulation of the expression of virulence factors. Most importantly, ITC reduced the toxicity of V. cholerae in the in vitro assays (against Vero and HeLa cells) and in vivo, using Galleria mellonella larvae as an infection model. In conclusion, our data indicate that ITCs might be considered promising antibacterial agents in V. cholerae infections.

The Anti-Inflammatory Properties of Phytochemicals and Their Effects on Epigenetic Mechanisms Involved in TLR4/NF-κB-Mediated Inflammation

Innate immune response induces positive inflammatory transducers and regulators in order to attack pathogens, while simultaneously negative signaling regulators are transcribed to maintain innate immune homeostasis and to avoid persistent inflammatory immune responses. The gene expression of many of these regulators is controlled by different epigenetic modifications. The remarkable impact of epigenetic changes in inducing or suppressing inflammatory signaling is being increasingly recognized. Several studies have highlighted the interplay of histone modification, DNA methylation, and post-transcriptional miRNA-mediated modifications in inflammatory diseases, and inflammation-mediated tumorigenesis. Targeting these epigenetic alterations affords the opportunity of attenuating different inflammatory dysregulations. In this regard, many studies have identified the significant anti-inflammatory properties of distinct naturally-derived phytochemicals, and revealed their regulatory capacity. In the current review, we demonstrate the signaling cascade during the immune response and the epigenetic modifications that take place during inflammation. Moreover, we also provide an updated overview of phytochemicals that target these mechanisms in macrophages and other experimental models, and go on to illustrate the effects of these phytochemicals in regulating epigenetic mechanisms and attenuating aberrant inflammation.

Potential of Sulforaphane as a Natural Immune System Enhancer: A Review

Brassicaceae are an outstanding source of bioactive compounds such as ascorbic acid, polyphenols, essential minerals, isothiocyanates and their precursors, glucosinolates (GSL). Recently, GSL gained great attention because of the health promoting properties of their hydrolysis products: isothiocyanates. Among them, sulforaphane (SFN) became the most attractive one owing to its remarkable health-promoting properties. SFN may prevent different types of cancer and has the ability to improve hypertensive states, to prevent type 2 diabetes–induced cardiomyopathy, and to protect against gastric ulcer. SFN may also help in schizophrenia treatment, and recently it was proposed that SFN has potential to help those who struggle with obesity. The mechanism underlying the health-promoting effect of SFN relates to its indirect action at cellular level by inducing antioxidant and Phase II detoxifying enzymes through the activation of transcription nuclear factor (erythroid-derived 2)-like (Nrf2). The effect of SFN on immune response is generating scientific interest, because of its bioavailability, which is much higher than other phytochemicals, and its capacity to induce Nrf2 target genes. Clinical trials suggest that sulforaphane produces favorable results in cases where pharmaceutical products fail. This article provides a revision about the relationship between sulforaphane and immune response in different diseases. Special attention is given to clinical trials related with immune system disorders.

Comparing the protective effects of resveratrol, curcumin and sulforaphane against LPS/IFN-γ-mediated inflammation in doxorubicin-treated macrophages

Doxorubicin (DOX) chemotherapy is associated with the release of inflammatory cytokines from macrophages. This has been suggested to be, in part, due to DOX-mediated leakage of endotoxins from gut microflora, which activate Toll-like receptor 4 (TLR4) signaling in macrophages, causing severe inflammation. However, the direct function of DOX on macrophages is still unknown. In the present study, we tested the hypothesis that DOX alone is incapable of stimulating inflammatory response in macrophages. Then, we compared the anti-inflammatory effects of curcumin (CUR), resveratrol (RES) and sulforaphane (SFN) against lipopolysaccharide/interferon-gamma (LPS/IFN-γ)-mediated inflammation in the absence or presence of DOX. For this purpose, RAW 264.7 cells were stimulated with LPS/IFN-γ (10 ng/mL/10 U/mL) in the absence or presence of DOX (0.1 µM). Our results showed that DOX alone is incapable of stimulating an inflammatory response in RAW 264.7 macrophages. Furthermore, after 24 h of incubation with LPS/IFN-γ, a significant increase in tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS) mRNA levels was observed. Similarly, nitric oxide (NO) production and TNF-α and IL-6 protein levels were significantly upregulated. Moreover, in LPS/IFN-γ-treated macrophages, the microRNAs (miRNAs) miR-146a, miR-155, and miR-21 were significantly overexpressed. Interestingly, upon testing CUR, RES, and SFN against LPS/IFN-γ-mediated inflammation, only SFN was able to significantly reverse the LPS/IFN-γ-mediated induction of iNOS, TNF-α and IL-6 and attenuate miR-146a and miR-155 levels. In conclusion, SFN, at the transcriptional and posttranscriptional levels, exhibits potent immunomodulatory action against LPS/IFN-γ-stimulated macrophages, which may indicate SFN as a potential treatment for DOX-associated inflammation.