Discovery of a crystalline sulforaphane analog with good solid-state stability and engagement of the Nrf2 pathway in vitro and in vivo

Microorganisms-An Effective Tool to Intensify the Utilization of Sulforaphane

Sulforaphane (SFN) was generated by the hydrolysis of glucoraphanin under the action of myrosinase. However, due to the instability of SFN, the bioavailability of SFN was limited. Meanwhile, the gut flora obtained the ability to synthesize myrosinase and glucoraphanin, which could be converted into SFN in the intestine. However, the ability of microorganisms to synthesize myrosinase in the gut was limited. Therefore, microorganisms with myrosinase synthesis ability need to be supplemented. With the development of research, microorganisms with high levels of myrosinase synthesis could be obtained by artificial selection and gene modification. Researchers found the SFN production rate of the transformed microorganisms could be significantly improved. However, despite applying transformation technology and regulating nutrients to microorganisms, it still could not provide the best efficiency during generating SFN and could not accomplish colonization in the intestine. Due to the great effect of microencapsulation on improving the colonization ability of microorganisms, microencapsulation is currently an important way to deliver microorganisms into the gut. This article mainly analyzed the possibility of obtaining SFN-producing microorganisms through gene modification and delivering them to the gut via microencapsulation to improve the utilization rate of SFN. It could provide a theoretical basis for expanding the application scope of SFN.

Application of ARE-reporter systems in drug discovery and safety assessment

The human body is continuously exposed to xenobiotics and internal or external oxidants. The health risk assessment of exogenous chemicals remains a complex and challenging issue. Alternative toxicological test methods have become an essential strategy for health risk assessment. As a core regulator of constitutive and inducible expression of antioxidant response element (ARE)-dependent genes, nuclear factor erythroid 2-related factor 2 (Nrf2) plays a critical role in maintaining cellular redox homeostasis. Consistent with the properties of Nrf2-mediated antioxidant response, Nrf2-ARE activity is a direct indicator of oxidative stress and thus has been used to identify and characterize oxidative stressors and redox modulators. To screen and distinguish chemicals or environmental insults that affect the cellular antioxidant activity and/or induce oxidative stress, various in vitro cell models expressing distinct ARE reporters with high-throughput and high-content properties have been developed. These ARE-reporter systems are currently widely applied in drug discovery and safety assessment. In the present review, we provide an overview of the basic structures and applications of various ARE-reporter systems employed for discovering Nrf2-ARE modulators and characterizing oxidative stressors.

Clinical Research Progress of Small Molecule Compounds Targeting Nrf2 for Treating Inflammation-Related Diseases

Studies have found that inflammation is a symptom of various diseases, such as coronavirus disease 2019 (COVID-19) and rheumatoid arthritis (RA); it is also the source of other diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), lupus erythematosus (LE), and liver damage. Nrf2 (nuclear factor erythroid 2-related factor 2) is an important multifunctional transcription factor in cells and plays a central regulatory role in cellular defense mechanisms. In recent years, several studies have found a strong association between the activation of Nrf2 and the fight against inflammation-related diseases. A number of small molecule compounds targeting Nrf2 have entered clinical research. This article reviews the research status of small molecule compounds that are in clinical trials for the treatment of COVID-19, rheumatoid arthritis, Alzheimer's disease, Parkinson's disease, lupus erythematosus, and liver injury.

Sulforaphane and Its Bifunctional Analogs: Synthesis and Biological Activity

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

Leukocyte Function in COPD: Clinical Relevance and Potential for Drug Therapy

Chronic obstructive pulmonary disease (COPD) is a progressive lung condition affecting 10% of the global population over 45 years. Currently, there are no disease-modifying treatments, with current therapies treating only the symptoms of the disease. COPD is an inflammatory disease, with a high infiltration of leukocytes being found within the lung of COPD patients. These leukocytes, if not kept in check, damage the lung, leading to the pathophysiology associated with the disease. In this review, we focus on the main leukocytes found within the COPD lung, describing how the release of chemokines from the damaged epithelial lining recruits these cells into the lung. Once present, these cells become active and may be driven towards a more pro-inflammatory phenotype. These cells release their own subtypes of inflammatory mediators, growth factors and proteases which can all lead to airway remodeling, mucus hypersecretion and emphysema. Finally, we describe some of the current therapies and potential new targets that could be utilized to target aberrant leukocyte function in the COPD lung. Here, we focus on old therapies such as statins and corticosteroids, but also look at the emerging field of biologics describing those which have been tested in COPD already and potential new monoclonal antibodies which are under review.

Food-Derived Pharmacological Modulators of the Nrf2/ARE Pathway: Their Role in the Treatment of Diseases

Oxidative stress, which refers to unbalanced accumulation of reactive oxygen species (ROS) levels in cells, has been linked to acute and chronic diseases. Nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway plays a vital role in regulating cytoprotective genes and enzymes in response to oxidative stress. Therefore, pharmacological regulation of Nrf2/ARE pathway is an effective method to treat several diseases that are mainly characterized by oxidative stress and inflammation. Natural products that counteract oxidative stress by modulating Nrf2 have contributed significantly to disease treatment. In this review, we focus on bioactive compounds derived from food that are Nrf2/ARE pathway regulators and describe the molecular mechanisms for regulating Nrf2 to exert favorable effects in experimental models of diseases.

Oxidative and Nitrosative Stress in the Pathogenesis of Obstructive Lung Diseases of Increasing Severity

The imbalance between increased oxidative agents and antioxidant defence mechanisms is central in the pathogenesis of obstructive lung diseases such as asthma and COPD. In these patients, there are increased levels of reactive oxygen species. Superoxide anions (O₂ -), Hydrogen Peroxide (H₂O₂) and hydroxyl radicals (•OH) are critical for the formation of further cytotoxic radicals in the bronchi and lung parenchyma. Chronic inflammation, partly induced by oxidative stress, can further increase the oxidant burden through activated phagocytic cells (neutrophils, eosinophils, macrophages), particularly in severer disease states. Antioxidants and anti-inflammatory genes are, in fact, frequently downregulated in diseased patients. Nrf2, which activates the Antioxidant Response Element (ARE) leading to upregulation of GPx, thiol metabolism-associated detoxifying enzymes (GSTs) and stressresponse genes (HO-1) are all downregulated in animal models and patients with asthma and COPD. An exaggerated production of Nitric Oxide (NO) in the presence of oxidative stress can promote the formation of oxidizing reactive nitrogen species, such as peroxynitrite (ONO₂ -), leading to nitration and DNA damage, inhibition of mitochondrial respiration, protein dysfunction, and cell damage in the biological systems. Protein nitration also occurs by activation of myeloperoxidase and H₂O₂, promoting oxidation of nitrite (NO₂ -). There is increased nitrotyrosine and myeloperoxidase in the bronchi of COPD patients, particularly in severe disease. The decreased peroxynitrite inhibitory activity found in induced sputum of COPD patients correlates with pulmonary function. Markers of protein nitration - 3- nitrotyrosine, 3-bromotyrosine, and 3-chlorotyrosine - are increased in the bronchoalveolar lavage of severe asthmatics. Targeting the oxidative, nitrosative stress and associated lung inflammation through the use of either denitration mechanisms or new drug delivery strategies for antioxidant administration could improve the treatment of these chronic disabling obstructive lung diseases.

Epigenetic repression of miR-17 contributed to di(2-ethylhexyl) phthalate-triggered insulin resistance by targeting Keap1-Nrf2/miR-200a axis in skeletal muscle

Rationale: Skeletal muscle insulin resistance is detectable before type 2 diabetes is diagnosed. Exposure to di(2-ethylhexyl) phthalate (DEHP), a typical environmental endocrine-disrupting chemical, is a novel risk factor for insulin resistance and type 2 diabetes. This study aimed to explore insulin signaling regulatory pathway in skeletal muscle of the DEHP-induced insulin-resistant mice and to investigate potential therapeutic strategies for treating insulin resistance. Methods: C57BL/6J male mice were exposed to 2 mg/kg/day DEHP for 15 weeks. Whole-body glucose homeostasis, oxidative stress and deregulated miRNA-mediated molecular transduction in skeletal muscle were examined. microRNA (miRNA) interventions based on lentiviruses and adeno-associated viruses 9 (AAV9) were performed. Results: Dnmt3a-dependent promoter methylation and lncRNA Malat1-related sponge functions cooperatively downregulated miR-17 in DEHP-exposed skeletal muscle cells. DEHP suppressed miR-17 to disrupt the Keap1-Nrf2 redox system and to activate oxidative stress-responsive Txnip in skeletal muscle. Oxidative stress upregulated miR-200a, which directly targets the 3'UTR of Insr and Irs1, leading to hindered insulin signaling and impaired insulin-dependent glucose uptake in skeletal muscle, ultimately promoting the development of insulin resistance. AAV9-induced overexpression of miR-17 and lentivirus-mediated silencing of miR-200a in skeletal muscle ameliorated whole-body insulin resistance in DEHP-exposed mice. Conclusions: The miR-17/Keap1-Nrf2/miR-200a axis contributed to DEHP-induced insulin resistance. miR-17 is a positive regulator, whereas miR-200a is a negative regulator of insulin signaling in skeletal muscle, and both miRNAs have the potential to become therapeutic targets for preventing and treating insulin resistance or type 2 diabetes.