Nrf2 Research Articles

Ferulic acid attenuated diethylnitrosamine-provoked hepato-renal damage and malfunction by suppressing oxidative stress, abating inflammation and upregulating nuclear factor erythroid related factor-2 signaling

Background Diethylnitrosamine (DEN) is a potent environmental toxin that can reach humans through the food chain. It induces proliferative, degenerative and cancerous lesions in the liver and kidneys. Objective The principal goal of the existing research was to assess the preventive impacts of ferulic acid (FA) versus DEN- provoked hepato-renal damage and malfunction. Materials and methods Adult male rats were divided into four groups: group 1 (normal control) animals orally received saline every day for 14 weeks; group 2 (DEN) animals intraperitoneally received DEN (150 mg/kg twice a week) for 2 weeks; group 3 (DEN + FA) animals were injected intraperitoneally twice a week with DEN for 2 weeks besides to oral administration of FA (100 mg/kg/day) for 14 weeks; group 4 (FA) animals were given a similar dose of FA for a similar period. Results The results revealed that FA treatment reversed the DEN-mediated elevation in serum values of the liver enzymes activities as well as urea and creatinine levels; it also augmented the hepato-renal antioxidant system that overcame DEN-induced oxidative stress deteriorations. Moreover, FA markedly reduced the DEN-induced elevated hepato-renal levels of immuno-inflammatory markers (IL-1β and TNF-α) as well as downregulated the inflammatory mediators (Bcl-2, NF-κB, and nuclear factor erythroid related factor-2 (Nrf-2)), reflecting its protective potential. Conclusion The existing results elucidate that ferulic acid could prevent and ameliorate DEN-induced hepato-renal toxicological changes and can restore livers and kidneys’ functions; this effect could be mechanized through activation of anti-inflammatory and antioxidant systems, as well as regulation of NF-κB, Bcl2, and nuclear factor erythroid related factor-2 expression.

Interleukin-17 alleviates erastin-induced alveolar bone loss by suppressing ferroptosis via interaction between NRF2 and p-STAT3.

To investigate the relationship between interleukin-17 (IL-17), ferroptosis and osteogenic differentiation. We first analysed the changes in ferroptosis-related molecules in experimental periodontitis models. The effects of erastin, a small-molecule ferroptosis inducer, and IL-17 on alveolar bone loss and repair in animal models were then investigated. Primary mouse mandibular osteoblasts were exposed to erastin and IL-17 in vitro. Ferroptosis- and osteogenesis-related genes and proteins were detected. Further, siRNA, immunofluorescence co-localization and immunoprecipitation were used to confirm the roles of the nuclear factor erythroid-2-related factor 2 (NRF2) and phosphorylated signal transducer and activator of transcription 3 (p-STAT3), as well as their interaction. The levels of NRF2, glutathione peroxidase 4 and solute carrier family 7 member 11 were lower in the ligated tissues than in normal periodontal tissues. Alveolar bone loss in an in vivo experimental periodontitis model was aggravated by erastin and alleviated by IL-17. In vitro, IL-17 ameliorated erastin-inhibited osteogenic differentiation by reversing ferroptosis. Altered NRF2 expression correlated with changes in ferroptosis-related molecules and osteogenesis. Furthermore, the physical interaction between NRF2 and p-STAT3 was confirmed in the nucleus. In IL-17 + erastin-stimulated osteoblasts, the p-STAT3-NRF2 complex might actively participate in the downstream transcription of ferroptosis- and osteogenesis-related genes. IL-17 administration conferred resistance to erastin-induced osteoblast ferroptosis and osteogenesis. The possible mechanism may involve p-STAT3 directly interacting with NRF2.

The Protective Effect of Marsdenia tenacissima against Cisplatin-Induced Nephrotoxicity Mediated by Inhibiting Oxidative Stress, Inflammation, and Apoptosis.

Cisplatin (Cis) is considered to be one of the most effective drugs for killing cancer cells and remains a first-line chemotherapeutic agent. However, Cis's multiple toxicities (especially nephrotoxicity) have limited its clinical use. Marsdenia tenacissima (Roxb.) Wight et Arn. (MT), a traditional Chinese medicine (TCM) employed extensively in China, not only enhances the antitumor effect in combination with Cis, but is also used for its detoxifying effect, as it reduces the toxic side effects of chemotherapy drugs. The aim of this study was to explore the therapeutic effect of MT on Cis-induced nephrotoxicity, along with its underlying mechanisms. In this study, liquid-mass spectrometry was performed to identify the complex composition of the extracts of MT. In addition, we measured the renal function, antioxidant enzymes, and inflammatory cytokines in mice with Cis-induced nephrotoxicity and conducted renal histology evaluations to assess renal injury. The expressions of the proteins related to antioxidant, anti-inflammatory, and apoptotic markers in renal tissues was detected by Western blotting (WB). MT treatment improved the renal function, decreased the mRNA expression of the inflammatory factors, and increased the antioxidant enzyme activity in mice. A better renal histology was observed after MT treatment. Further, MT inhibited the expression of the phospho-NFκB p65 protein/NFκB p65 protein (p-p65)/p65, phospho-inhibitor of nuclear factor kappa B kinase beta subunit/inhibitor of nuclear factor kappa B kinase beta subunit (p-IKKβ/IKKβ), Bcl-2-associated X (Bax), and Cleaved Caspase 3/Caspase 3 proteins, while the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Recombinant NADH Dehydrogenase, Quinone 1 (NQO1), and B-cell lymphoma-2 (Bcl-2) was increased. The present study showed that MT ameliorated renal injury, which mainly occurs through the regulation of the Nrf2 pathway, the NF-κB pathway, and the suppression of renal tissue apoptosis. It also suggests that MT can be used as an adjuvant to mitigate the nephrotoxicity of Cis chemotherapy.

Resveratrol alleviates fumonisin-induced intestinal cytotoxicity by modulating apoptosis, tight junction, and inflammation in IPEC-J2 porcine intestinal epithelial cells.

Fumonisins are common contaminants in the global food and environment, pose a variety of health risks to humans and animals. However, the method of mitigating fumonisin toxicity is still unclear. Resveratrol is a natural compound with antioxidant and anti-inflammatory properties. In this study, the protective effect of resveratrol against fumonisin-induced intestinal toxicity was investigated by the porcine intestinal epithelial cell line (IPEC-J2). The cells were treated with 0-40 μM fumonisin for 24 or 48 h with or without the 24 h resveratrol (15 μM) pretreatment. The data showed that resveratrol could alleviate the fumonisin B1 (FB1)-induced decrease in cell viability and amplify in membrane permeability. At the same time, it could reduce the accumulation of intracellular reactive oxygen species and increase the expression ranges of Nrf2 and downstream genes (SOD1 and NQO-1), thereby counteracting FB1-induced apoptosis. Furthermore, resveratrol was able to reduce the expression levels of inflammatory factors (TNF-α, IL-1β, and IL-6), increase the expression levels of tight junction proteins (Claudin-1, Occludin, and ZO-1), and the integrity of the IPEC-J2 monolayer. Our data also showed that resveratrol could attenuate the toxicity of the co-occurrence of three fumonisins. It is implied that resveratrol represents a promising protective approach for fumonisin, even other mycotoxins in the future. This provided a new strategy for further blocking and controlling the toxicity of fumonisin, subsequently avoiding adverse effects on the human and animal health.

Cytoprotective–Antioxidant Effect of Brunfelsia grandiflora Extract on Neuron-like Cells

Brunfelsia grandiflora is a South American solanaceae widely used since long ago for its recognized medicinal properties. We have recently reported its chemical composition, showing a relevant number of bioactive compounds with antioxidant capacity, and proved the cytoprotective and antioxidative stress potential of B. grandiflora in cultured endothelial cells. Since B. grandiflora extracts have shown effects on the central nervous system, the present study was designed to show the potential cytoprotective capacity and the antioxidative stress potential of phenolic extracts from the plant on cultured neuron-like cells, as a model to reduce the presentation or effects of chronic diseases of the nervous system. To this end, we studied its reactive oxygen species (ROS)-reducing capacity, its antioxidant defense mechanisms, and some molecular markers involved in redox balance and apoptosis. The results show that cell survival and most changes in biomarkers related to oxidative status, ROS, reduced glutathione, glutathione peroxidase and reductase, malondialdehyde, and caspase 3/7 activity, and molecular expression of cell death-related genes (BAX, BNIP3, and APAF1), NFκB, SOD, and NRF2 (genes from oxidative stress—antioxidants) induced by oxidative stress were prevented by either co- or pretreatment of neuron-like cells with B. grandiflora extracts (25–200 µg/mL). The results demonstrate the chemoprotective potential of the plant and support its medicinal use.

Antioxidant effect of lactic acid bacteria in human bronchial epithelial cells exposed to cigarette smoke.

Chronic lung diseases are a major and increasing global health problem, commonly caused by cigarette smoke. We aimed to explore the antioxidant effects of lactic acid bacteria (LAB) against cigarette smoke in bronchial epithelial cells. The antioxidant effects of 21 heat-killed (HK) LAB strains were tested in cigarette smoke stimulated BEAS-2B cells and 3-D bronchospheres organoids. We showed that HK Lactiplantibacillus plantarum BGPKM22 possesses antioxidant activity against cigarette smoke, resistance to hydrogen peroxide, and free radical neutralizing activity. We demonstrated that HK BGPKM22 inhibited cigarette smoke induced expression of the Aryl hydrocarbon receptor (AhR) and Nuclear factor erythroid 2 related factor 2 (Nrf2) genes. The cell-free supernatant (SN) of BGPKM22 fully confirmed the effects of HK BGPKM22. For the first time, we revealed that HK and SN of L. plantarum BGPKM22 possess antioxidant activity and modulate AhR and Nrf2 gene expression in bronchial epithelial cells exposed to cigarette smoke.

Dimethyl fumarate modulates the dystrophic disease program following short-term treatment.

New medicines are urgently required to treat the fatal neuromuscular disease, Duchenne muscular dystrophy (DMD). Dimethyl fumarate (DMF) is a potent immunomodulatory small molecule nuclear erythroid 2-related factor 2 (Nrf2) activator with current clinical utility in the treatment of multiple sclerosis and psoriasis that could be effective for DMD and rapidly translatable. Here, we tested two weeks of daily 100mg/kg DMF versus 5mg/kg standard care prednisone (PRED) treatment in juvenile mdx mice with early symptomatic DMD. Both drugs modulated seed genes driving the DMD disease program and improved force production in fast-twitch muscle. However, only DMF showed pro-mitochondrial effects, protected contracting muscles from fatigue, improved histopathology and augmented clinically compatible muscle function tests. DMF may be a more selective modulator of the DMD disease program than PRED warranting follow-up longitudinal studies to evaluate disease modifying impact.

Biogenic Selenium Nanoparticles Synthesized with Alginate Oligosaccharides Alleviate Heat Stress-Induced Oxidative Damage to Organs in Broilers through Activating Nrf2-Mediated Anti-Oxidation and Anti-Ferroptosis Pathways.

Selenium (Se) is an essential trace element for maintaining health due to its ideal antioxidant properties. We previously prepared a new type of biogenic selenium nanoparticles based on alginate oligosaccharides (SeNPs-AOS), and this study aimed to investigate the protective effects of SeNPs-AOS (Se particle size = 80 nm, Se content = 8%) on organ health in broilers challenged with HS. A total of 192 21-day-old Arbor Acres broilers were randomly divided into four groups according to a 2 × 2 experimental design, including a thermoneutral zone group (TN, raised under 23 ± 1.5 °C); TN + SeNPs-AOS group (TN group supplemented 5 mg/kg SeNPS-AOS); HS group (HS, raised under 33 ± 2 °C for 10 h/day); and HS + SeNPs-AOS group (HS group supplemented 5 mg/kg SeNPS-AOS). There were six replicates in each group (eight broilers per replicate). The results showed that SeNPs-AOS improved the splenic histomorphology, enhanced the activity of catalase (CAT) and glutathione peroxidase (GSH-Px) of the spleen, as well as upregulating the splenic mRNA expression of antioxidant-related genes in broilers under HS. In addition, SeNPs-AOS reversed the pathological changes in bursa caused by HS increased the activity of GST, GSH-Px, and CAT and upregulated the mRNA expression of Nrf2 and antioxidant-related genes in the bursa of heat-stressed broilers. In addition, dietary SeNPs-AOS improved the hepatic damage, increased the activity of GSH-Px in the liver, and upregulated the mRNA expression of antioxidant-related genes while downregulating the Keap1 gene expression of the liver in broilers during HS. Moreover, dietary SeNPs-AOS upregulated the anti-ferroptosis-related genes expression of liver in broilers under HS. In conclusion, dietary SeNPs-AOS could relieve HS-induced oxidative damage to the spleen, bursa of Fabricius and liver in broilers by upregulating the Nrf2-mediated antioxidant gene expression and SeNPs-AOS could also upregulate the expression of hepatic Nrf2-related anti-ferroptosis genes in heat-stressed broilers. These findings are beneficial for the development of new nano-antioxidants in broilers.

Dimethyl Fumarate Attenuates Methotrexate Hepatotoxicity in Mice Via the Nrf2/HO-1/Anti-Apoptotic Signaling Pathway

Background: Methotrexate (MTX), a folate antagonist used to treat cancer and inflammatory diseases, is known to generate reactive oxygen species. Objectives: The research investigates the impact of dimethyl fumarate (DMF), a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, on an MTX-induced mouse hepatotoxicity model. Methods: Forty-two mice were divided into 6 groups: Control, MTX, DMF 120, and 3 groups of MTX co-treated with DMF 30, 60, and 120 mg/kg. Dimethyl fumarate was gavaged once daily for 10 days. On the fifth day, the animals received MTX 20 mg/kg intraperitoneally. On the eleventh day, the animals were sacrificed, and serum and liver samples were collected to assess the level of oxidative/anti-oxidative and apoptotic/anti-apoptotic markers. Results: Dimethyl fumarate prevented the increase of liver function enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) induced by MTX (P < 0.001). It prevented the increase in AST and ALT levels, indicating liver recovery (P < 0.001). Furthermore, DMF restored antioxidant markers superoxide dismutase, catalase, glutathione peroxidase, and total thiol while reducing the level of thiobarbituric acid reactive substances (P < 0.001). Dimethyl fumarate also downregulated hepatic mRNA expression of caspase 3 and upregulated Bcl-2, heme oxygenase 1, and Nrf2 genes in MTX co-treated DMF groups. Conclusions: Dimethyl fumarate alleviates oxidative stress and apoptosis, which may be achieved by the Nrf2/HO-1 pathway. Therefore, DMF may be clinically effective in preventing or treating MTX-induced hepatotoxicity.

Circulating microRNAs as novel biomarkers for measuring the potency of ginger extract against cyclophosphamide toxicity in rat renal tissues: molecular and histopathological study.

This study aims to explore underlying molecular variations in the expression of miRNAs in kidney tissues of ginger-treated and non-treated cyclophosphamide (CP)-intoxicated rats. A total of 40 adult male Wistar rats were randomly divided into four groups of 10 each: Group I (control: received normal food and water), Group II (received ginger at a dose of 300 mg/kg), Group III (received CP 75 mg/kg, i.p.), and Group IV (received the same dose of CP and ginger extract). Rats received a single injection of 75 mg/kg CP on days 3, 4, 5, 19, 20, and 21. In CP-intoxicated rats, the treatment with ginger extract at a dose of 300 mg/kg was received by oral gavage starting seven days before CP and continuing throughout the duration of the experiment for four weeks. Molecular variations in the expression of miRNAs, apoptotic genes, histological kidney damage, and abnormal kidney function in control, ginger, and CP-intoxicated rats were identified by using real-time RT-PCR Analysis, immunohistochemical, and colorimetric assays. In addition, HPLC analysis and liquid chromatography spectrophotometry analysis using Diphenyl-1-picrylhydrazyl (DPPH) radical, and Β-Carotene-linoleic acid reagents were applied respectively for in-vitro screening of phytoconstituents and antioxidant activity for ginger extract. The kidney tissues of CP-intoxicated rats displayed an increase in lipid peroxidation marker malonaldehyde (MDA), DNA damage, and fibrosis markers like hyaluronic acid (HA) and hydroxyproline Hypx) with a decrease in the superoxide dismutase (SOD) and total antioxidant capacity (TAC). In addition, molecular expressions of mRNA fibrotic genes such as collagen, type 1, alpha 1 (COL1A1), and α-smooth muscle actin (αSMA). Molecular expressions of levels of B-cell lymphoma 2 (BCl-2) mRNA gene were down-regulated, and the expression of mRNA apoptotic; BCL2 associated X gene (Bax), caspase-3, Bax/BCl-2 ratio genes were significantly up-regulated respectively. Moreover, cellular oxidative genes, erythroid 2-related factor (Nrf2), and heme oxygenase-1 (HO-1) were down-regulated, respectively. The miR-155-5p, miR-34a-5p, miR-21-5p significantly increased while the miR-193b-3p, miR-455-3p, and miR-342-3p significantly decreased. Ginger also increased the expression of Nrf2, HO-1, and BCl-2 genes in the kidneys of rats induced with CP. In addition, active phytoconstituents, particularly 6]]-shogaol and 6]]-gingerol, were significantly identified in ginger extract using HPLC analysis. Antioxidant activity of these active metabolites were shown to be higher against in vitro free radicals (DPPH and Β-Carotene-linoleic acid), suggesting the potential antioxidant and antiapoptotic properties of ginger against CP-toxicity. Treatment with ginger in rats induced with CP resulted in significant improvement in the expression of certain molecular miRNAs. The kidney tissues of these rats showed a marked decrease in the expression of miR-155-5p, miR-34a-5p, and miR-21-5p, while the levels of miR-193b-3p, miR-455-3p, and miR-342-3p were observed to increase significantly. In conclusion, ginger can protect rats from CP-induced nephrotoxicity.

Fecal Microbiota Transplantation in Mice Exerts a Protective Effect Against Doxorubicin-Induced Cardiac Toxicity by Regulating Nrf2-Mediated Cardiac Mitochondrial Fission and Fusion.

Aims: The relationship between the gut microbiota and cardiovascular system has been increasingly clarified. Fecal microbiota transplantation (FMT), used to improve gut microbiota, has been applied clinically for disease treatment and has great potential in combating doxorubicin (DOX)-induced cardiotoxicity. However, the application of FMT in the cardiovascular field and its molecular mechanisms are poorly understood. Results: During DOX-induced stress, FMT alters the gut microbiota and serum metabolites, leading to a reduction in cardiac injury. Correlation analysis indicated a close association between serum metabolite indole-3-propionic acid (IPA) and cardiac function. FMT and IPA achieve this by facilitating the translocation of Nfe2l2 (Nrf2) from the cytoplasm to the nucleus, thereby activating the expression of antioxidant molecules, reducing reactive oxygen species production, and inhibiting excessive mitochondrial fission. Consequently, mitochondrial function is preserved, leading to the mitigation of cardiac injury under DOX-induced stress. Innovation: FMT has the ability to modify the composition of the gut microbiota, providing not only protection to the intestinal mucosa but also influencing the generation of serum metabolites and regulating the Nrf2 gene to modulate the balance of cardiac mitochondrial fission and fusion. This study comprehensively demonstrates the efficacy of FMT in countering DOX-induced myocardial damage and elucidates the pathways linking the microbiota and the heart. Conclusion: FMT alters the gut microbiota and serum metabolites of recipient mice, promoting nuclear translocation of Nrf2 and subsequent activation of downstream antioxidant molecule expression, while inhibiting excessive mitochondrial fission to preserve cardiac integrity. Correlation analysis highlights IPA as a key contributor among differentially regulated metabolites.

Research progress of chlorogenic acid in improving inflammatory diseases.

Long-term inflammation will develop into chronic inflammation and become inflammatory diseases. Antibiotics are commonly used in clinical practice to treat inflammatory diseases. But patients are prone to drug resistance. So we need to find new treatment. Chlorogenic acid is an organic compound extracted from honeysuckle and other plants. Its anti-inflammatory activity is strong, and it has a significant anti-inflammatory effect on inflammatory diseases in various systems. It has been shown that chlorogenic acid can regulate inflammation-related signaling pathways, such as nuclear factor κB (NF-κB) canonical signaling pathway, NF-κB atypical signaling pathway, nuclear factor-erythroid 2-related factor 2 (Nrf2) canonical signaling pathway, and Nrf2 atypical signaling pathway, etc. It can up-regulate the expression of anti-inflammatory cytokines such as interleukin (IL)-4, IL-10, IL-13 and down-regulate the expression of pro-inflammatory cytokine such as IL-1β, IL-6, and IL-8. Although chlorogenic acid has a strong anti-inflammatory effect, but clinical trials and application still face many difficulties. In the future, the anti-inflammatory molecular mechanism of chlorogenic acid should be further studied to explore its clinical application value and improve new ideas for the treatment of inflammatory diseases.

Ethanol Extract of Rosa rugosa Ameliorates Acetaminophen-Induced Liver Injury via Upregulating Sirt1 and Subsequent Potentiation of LKB1/AMPK/Nrf2 Cascade in Hepatocytes

Acetaminophen (APAP)-induced liver injury is a common hepatic disease resulting from drug abuse. Few targeted treatments are available clinically nowadays. The flower bud of Rosa rugosa has a wide range of biological activities. However, it is unclear whether it alleviates liver injury caused by APAP. Here, we prepared an ethanol extract of Rosa rugosa (ERS) and analyzed its chemical profile. Furthermore, we revealed that ERS significantly ameliorated APAP-induced apoptosis and ferroptosis in AML-12 hepatocytes and dampened APAP-mediated cytotoxicity. In AML-12 cells, ERS elevated Sirt1 expression, boosted the LKB1/AMPK/Nrf2 axis, and thereby crippled APAP-induced intracellular oxidative stress. Both EX527 and NAM, which are chemically unrelated inhibitors of Sirt1, blocked ERS-induced activation of LKB1/AMPK/Nrf2 signaling. The protection of ERS against APAP-triggered toxicity in AML-12 cells was subsequently abolished. As expression of LKB1 was knocked down, ERS still upregulated Sirt1 but failed to activate AMPK/Nrf2 cascade or suppress cytotoxicity provoked by APAP. Results of in vivo experiments showed that ERS attenuated APAP-caused hepatocyte apoptosis and ferroptosis and improved liver injury and inflammation. Consistently, ERS boosted Sirt1 expression, increased phosphorylations of LKB1 and AMPK, and promoted Nrf2 nuclear translocation in the livers of APAP-intoxicated mice. Hepatic transcriptions of HO-1 and GCLC, which are downstream antioxidant genes of Nrf2, were also significantly increased in response to ERS. Our results collectively indicated that ERS effectively attenuates APAP-induced liver injury by activating LKB1/AMPK/Nrf2 cascade. Upregulated expression of Sirt1 plays a crucial role in ERS-mediated activation of LKB1.

Plant & its Bioactive Components Uses in Cardio-Potential Diseases: A Sectional Study for Different Herbs

Thirty percent of all deaths that occur each year can be attributed to heart disease, stroke, and other forms of cardiovascular disease. The World Health Organisation (WHO) predicts that by the year 2030, the annual death toll from cardiovascular diseases will have increased to 22.2 million, up from the present annual total of 17.9 million. Mortality rates tend to go up in populations as they get older. The chance of dying from cardiovascular disease is significantly higher for females (51%) than it is for males (42%). The majority of people treat and prevent cardiovascular disease by using plant-based medications (also known as phytochemicals), either in addition to or in instead of pharmaceuticals that are readily available on the market. In this study, the efficacy of treating cardiovascular illness is evaluated using 92 different plants, including 15 terrestrial plants. A number of different medicinal herbs, including Daucus carota, Nerium oleander, Amaranthus Viridis, Ginkgo biloba, Terminalia arjuna, Picrorhiza kurroa, Salvia miltiorrhiza, Tinospora cordifolia, Mucuna pruriens, Hydrocotyle asiatica, Bombax ceiba, and Andrographis paniculate, are utilised to treat cardiovascular disease. There are a variety of active phytochemicals found in these plants, some of which include flavonoids, polyphenols, plant sterols, plant sulphur compounds, and terpenoids. Flavonoids, in general, are known to increase vasodilation by inhibiting the oxidation of low-density lipoprotein (LDL). Plant sterols reduce the amount of cholesterol in the blood, which in turn protects against cardiovascular disease. Plant sulphur compounds protect against cardiovascular disease in addition to their role in the activation of nuclear factor-erythroid factor 2-related factor 2 (Nrf2) and the inhibition of cholesterol formation. The incidence of cardiovascular disease can be reduced by increasing the synthesis of ATP in mitochondria, and terpenoids can diminish atherosclerotic lesion in the aortic valve. Even though several physiologically active compounds with acknowledged biological functions have been found in a wide variety of plants, the prevalence of cardiovascular disease continues to rise, making it imperative that effective CVD prevention and treatment strategies be developed. More research is required to understand both the mechanism and the individual phytochemicals in plants that treat CVD.
 GRAPHICAL ABSTRACT 

Discovery and Anti-Inflammatory Activity of a Cyanobacterial Fatty Acid Targeting the Keap1/Nrf2 Pathway.

The monounsaturated fatty acid 7(E)-9-keto-hexadec-7-enoic acid (1) and three structurally related analogues with different oxidation states and degrees of unsaturation (2-4) were discovered from a marine benthic cyanobacterial mat collected from Delta Shoal, Florida Keys. Their structures were elucidated using NMR spectroscopy and mass spectrometry. The structure of 1 contained an α,β-unsaturated carbonyl system, a key motif required for the activation of the Keap1/Nrf2-ARE pathway that is involved in the activation of antioxidant and phase II detoxification enzymes. Compounds 1-4 were screened in ARE-luciferase reporter gene assay using stably transfected HEK293 cells, and only 1 significantly induced Nrf2 activity at 32 and 10 µM, whereas 2-4 were inactive. As there is crosstalk between inflammation and oxidative stress, subsequent biological studies were focused on 1 to investigate its anti-inflammatory potential. Compound 1 induced Nqo1, a well-known target gene of Nrf2, and suppressed iNos transcript levels, which translated into reduced levels of nitric oxide in LPS-activated mouse macrophage RAW264.7 cells, a more relevant model for inflammation. RNA sequencing was performed to capture the effects of 1 on a global level and identified additional canonical pathways and upstream regulators involved in inflammation and immune response, particularly those related to multiple sclerosis. A targeted survey of marine cyanobacterial samples from other geographic locations, including Guam, suggested the widespread occurrence of 1. Furthermore, the previous isolation of 1 from marine diatoms and green algae implied a potentially important ecological role across marine algal eukaryotes and prokaryotes. The previous isolation from sea lettuce raises the possibility of dietary intervention to attenuate inflammation and related disease progression.

Antioxidant System and Endoplasmic Reticulum Stress in Cataracts.

The primary underlying contributor for cataract, a leading cause of vision impairment and blindness worldwide, is oxidative stress. Oxidative stress triggers protein damage, cell apoptosis, and subsequent cataract formation. The nuclear factor-erythroid 2-related factor 2 (Nrf2) serves as a principal redox transcriptional factor in the lens, offering a line of defense against oxidative stress. In response to oxidative challenges, Nrf2 dissociates from its inhibitor, Kelch-like ECH-associated protein 1 (Keap1), moves to the nucleus, and binds to the antioxidant response element (ARE) to activate the Nrf2-dependent antioxidant system. In parallel, oxidative stress also induces endoplasmic reticulum stress (ERS). Reactive oxygen species (ROS), generated during oxidative stress, can directly damage proteins, causing them to misfold. Initially, the unfolded protein response (UPR) activates to mitigate excessive misfolded proteins. Yet, under persistent or severe stress, the failure to rectify protein misfolding leads to an accumulation of these aberrant proteins, pushing the UPR towards an apoptotic pathway, further contributing to cataractogenesis. Importantly, there is a dynamic interaction between the Nrf2 antioxidant system and the ERS/UPR mechanism in the lens. This interplay, where ERS/UPR can modulate Nrf2 expression and vice versa, holds potential therapeutic implications for cataract prevention and treatment. This review explores the intricate crosstalk between these systems, aiming to illuminate strategies for future advancements in cataract prevention and intervention. The Nrf2-dependent antioxidant system communicates and cross-talks with the ERS/UPR pathway. Both mechanisms are proposed to play pivotal roles in the onset of cataract formation.

SLC38A5 Modulates Ferroptosis to Overcome Gemcitabine Resistance in Pancreatic Cancer.

Pancreatic cancer is characterized by a poor prognosis, with its five-year survival rate lower than that of any other cancer type. Gemcitabine, a standard treatment for pancreatic cancer, often has poor outcomes for patients as a result of chemoresistance. Therefore, novel therapeutic targets must be identified to overcome gemcitabine resistance. Here, we found that SLC38A5, a glutamine transporter, is more highly overexpressed in gemcitabine-resistant patients than in gemcitabine-sensitive patients. Furthermore, the deletion of SLC38A5 decreased the proliferation and migration of gemcitabine-resistant PDAC cells. We also found that the inhibition of SLC38A5 triggered the ferroptosis signaling pathway via RNA sequencing. Also, silencing SLC38A5 induced mitochondrial dysfunction and reduced glutamine uptake and glutathione (GSH) levels, and downregulated the expressions of GSH-related genes NRF2 and GPX4. The blockade of glutamine uptake negatively modulated the mTOR-SREBP1-SCD1 signaling pathway. Therefore, suppression of SLC38A5 triggers ferroptosis via two pathways that regulate lipid ROS levels. Similarly, we observed that knockdown of SLC38A5 restored gemcitabine sensitivity by hindering tumor growth and metastasis in the orthotopic mouse model. Altogether, our results demonstrate that SLC38A5 could be a novel target to overcome gemcitabine resistance in PDAC therapy.

Macrophage specific restoration of the Nrf2 gene in whole-body knockout mice ameliorates steatohepatitis induced by lipopolysaccharide from Porphyromonas gingivalis through enhanced hepatic clearance.

Lipopolysaccharide (LPS) derived from Porphyromonas gingivalis (P.g.), which causes periodontal disease, contributes to the development of non-alcoholic steatohepatitis (NASH). We investigated the role of Nrf2, an antioxidative stress sensor, in macrophages in the development of NASH induced by LPS from P.g. We generated macrophage-specific Nrf2 gene rescue mice (Nrf2-mRes), which express Nrf2 only in macrophages, using the cre/loxp system. Wild-type (WT) mice, whole body Nrf2-knockout (Nrf2-KO) mice, and Nrf2-mRes mice were fed a high-fat diet for 18 weeks, and LPS from P.g. was administered intraperitoneally for the last 6 weeks. Nrf2-KO mice developed severe steatohepatitis with liver inflammation and fibrosis compared with WT mice, and steatohepatitis was ameliorated in Nrf2-mRes mice. The mRNA expressions of Toll-like receptor (Tlr)-2, which activates inflammatory signaling pathways after LPS binding, and α-smooth muscle actin (αSma), which promotes hepatic fibrosis, were reduced in Nrf2-mRes mice compared with Nrf2-KO mice. The protein levels of LPS-binding protein in livers were increased in Nrf2-KO mice compared with WT mice; however, the levels were reduced in Nrf2-mRes mice despite similar numbers of F4/80 positive cells, which reflect macrophage/Kupffer cell infiltration into the livers. Nrf2 in macrophages ameliorates NASH through the increased hepatic clearance of LPS.

Hydrogen sulfide inhibits gene expression associated with aortic valve degeneration by inducing NRF2-related pro-autophagy effect in human aortic valve interstitial cells.

Aortic valve stenosis (AS) is the most common valvular heart disease but there are currently no effective medical treatments that can delay disease progression due to a lack of knowledge of the precise pathophysiology. The expression of sulfide: quinone oxidoreductase (SQOR) and nuclear factor erythroid 2-related factor 2 (NRF2) was decreased in the aortic valve of AS patients. However, the role of SQOR and NRF2 in the pathophysiology of AS has not been found. We investigated the effects of hydrogen sulfide (H2S)-releasing compounds on diseased aortic valve interstitial cells (AVICs) to explain the cellular mechanism of SQOR and elucidate the medical value of H2S for AS treatment. Sodium hydrosulfide (NaHS) treatment increased the expression of SQOR and NRF2 gene and consequently induced the NRF2 target genes, such as NAD(P)H quinone dehydrogenase 1 and cystathionine γ-lyase. In addition, NaHS dose-dependently decreased the expression level of fibrosis and inflammation-related genes (MMP9, TNF-α, IL6) and calcification-related genes (ALP, osteocalcin, RUNX2, COL1A1) in human AVICs. Furthermore, NaHS activated the AMPK-mTOR pathway and inhibited the PI3K-AKT pathway, resulting in a pro-autophagy effect in human AVICs. An NRF2 inhibitor, brusatol, attenuated NaHS-induced AMPK activation and decreased the autophagy markers Beclin-1 and LC3AB, suggesting that the mechanism of action of H2S is related to NRF2. In conclusion, H2S decreased gene expression levels related to aortic valve degeneration and activated AMPK-mTOR-mediated pro-autophagy function associated with NRF2 in human AVICs. Therefore, H2S could be a potential therapeutic target for the development of AS treatment.

Combination of Cysteine and Glutathione Prevents Ethanol-Induced Hangover and Liver Damage by Modulation of Nrf2 Signaling in HepG2 Cells and Mice.

Excessive alcohol consumption increases oxidative stress, leading to alcoholic liver disease. In this study, the protective effects of a mixture of cysteine and glutathione against ethanol-induced hangover and liver damage were evaluated in mice and HepG2 cells. Ethanol (2 mL/kg) was orally administered to the mice 30 min before receiving the test compounds (200 mg/kg), and the behavioral and oxidative stress-related biochemical parameters altered by ethanol were analyzed. Acute ethanol administration increased anxiety behavior and decreased balance coordination in mice (p < 0.001); however, a mixture of cysteine and glutathione (MIX) in a 3:1 ratio improved alcohol-induced behavior more effectively than the individual compounds (p < 0.001). The MIX group showed higher ethanol-metabolizing enzyme activity than the control group (p < 0.001) and significantly suppressed the elevation of serum alcohol (p < 0.01) and acetaldehyde (p < 0.001) levels after 1 h of ethanol administration. In HepG2 cells, 2.5 mM MIX accelerated ethanol metabolism and reduced cytochrome P450 2E1 mRNA expression (p < 0.001). MIX also increased the expression of antioxidant enzymes through the upregulation of nuclear erythroid 2-related factor 2 (Nrf2) signaling and consequently suppressed the overproduction of reactive oxygen species and malondialdehyde (p < 0.001). Collectively, MIX alleviates the hangover symptoms and attenuates the alcohol-induced oxidative stress by regulating the Nrf2 pathway.