FOXC2 Alleviates Myocardial Ischemia-Reperfusion Injury in Rats through Regulating Nrf2/HO-1 Signaling Pathway

OBJECTIVE

Myocardial ischemia-reperfusion injury (MIRI) is the leading cause of death in patients with cardiovascular disease. The purpose of this study is to investigate the effect and mechanism of forkhead box C2 (FOXC2) on MIRI in rats.

METHODS

We made ischemia-reperfusion (I/R) models for rats by performing I/R surgery. After 3 hours, 3 days, and 7 days of reperfusion, we detected the structure and function of rat myocardium by 2, 3, 5-triphenyl tetrazolium chloride staining, echocardiography, lactate dehydrogenase kit, and haematoxylin-eosin staining. The change of FOXC2 expression in myocardial tissue was also detected. Then, we increased the expression of FOXC2 in rats by adenovirus transfection to clarify the effect of FOXC2 on changes of oxidative stress and inflammation of rat myocardium. In addition, we detected the effect of FOXC2 overexpression plasmid on the function of H9c2 cells in vitro. The expression changes of Nrf2/HO-1 in myocardial cells were also detected to clarify the mechanism of action of FOXC2.

RESULTS

The expression of FOXC2 in I/R rats was significantly lower than that in the sham group. After overexpressing FOXC2 in I/R rats, we found that the expression of SOD1/2 of rat myocardium and inflammatory factors in the serum were significantly reduced. Overexpression of FOXC2 also increased the viability and antioxidant capacity of H9c2 cells. In addition, FOXC2 was found to increase the activity of the Nrf2/HO-1 signaling pathway in myocardial cells, and the inhibition of Nrf2/HO-1 signaling pathway attenuated the protective effect of FOXC2 on myocardial cells.

CONCLUSIONS

MIRI in rats was accompanied by low expression of FOXC2 in myocardial tissue. Overexpression of FOXC2 reduces the level of inflammation and oxidative stress in myocardial tissue by promoting the Nrf2/HO-1 signaling pathway, thereby alleviating MIRI.

Olmesartan niosomes ameliorates the Indomethacin-induced gastric ulcer in rats: Insights on MAPK and Nrf2/HO-1 signaling pathway

AIMS

Gastric ulcer is a continuous worldwide threat that inquires protective agents. Olmesartan (OLM) has potent anti-oxidant and anti-inflammatory characters, yet having limited bioavailability. We targeted the gastro-protective potential and probable mechanism of OLM and its niosomal form against indomethacin (IND) induced-gastric ulcer in rats.

MAIN METHODS

we prepared OLM niosomes (OLM-NIO) with different surfactant: cholesterol molar ratios. We evaluated particle size, zeta-potential, polydispersity, and entrapment efficiency. In-vitro release study, Fourier transform infrared spectroscopy, differential scanning calorimetry, and transmission electron microscopy were performed for selected niosomes. In-vivo, we used oral Omeprazole (30 mg/kg), OLM or OLM-NIO (10 mg/kg) for 3 days before IND (25 mg/kg) ingestion. We assessed gastric lesions, oxidative and inflammatory markers.

KEY FINDINGS

OLM-NIO prepared with span 60:cholesterol ratio (1:1) showed high entrapment efficiency 93 ± 2%, small particle size 159.3 ± 6.8 nm, low polydispersity 0.229 ± 0.009, and high zeta-potential -35.3 ± 1.2 mV, with sustained release mechanism by release data. In-vivo macroscopical and histological results showed gastro-protective effects of OLM pretreatment, which improved oxidative stress parameters and enhanced the gastric mucosal cyclooxygenase-1 (COX-1) and prostaglandin E2 (PGE2) contents. OLM pretreatment suppressed interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) contents and translocation of p38 mitogen-activated protein kinase (p38-MAPK). Besides, OLM substantially promoted the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) protective pathway. OLM-NIO furtherly improved all previous outcomes.

SIGNIFICANCE

We explored OLM anti-ulcerative effects, implicating oxidative stress and inflammation improvement, mediated by the Nrf2/HO-1 signaling pathway and p38-MAPK translocation. Meanwhile, the more bioavailable OLM-NIO achieved better gastro-protective effects compared to conventional OLM form.

Integrating network pharmacology and experimental evidence to decipher the cardioprotective mechanism of Yiqihuoxue decoction in rats after myocardial infarction

ETHNOPHARMACOLOGICAL RELEVANCE

"Qi deficiency and blood stasis" syndrome is one of the most common syndromes treated with Traditional Chinese Medicine among ischemic heart disease (IHD) patients in clinic. As a Chinese herbal formula with the function of tonifying Qi and activating blood, Yiqihuoxue Decoction (YQHX) has been frequently proven to be effective in the clinical treatment of IHD.

AIM OF THE STUDY

The cardioprotective mechanisms of YQHX in treating ischemic heart disease were investigated, with emphasis on the key targets and pathways.

MATERIALS AND METHODS

In the present study, the potential targets of compounds identified in YQHX were predicted using PharmMapper, Symmap, and STITCH databases, and a "herb-compound-target" network was constructed using Cytoscape. Subsequently, the GO and KEGG functional enrichment analyses were analyzed using the DAVID database. Furthermore, a protein-protein interaction network was constructed using STRING to obtain the key target information. Besides, we used a myocardial ischemia rat model to investigate the cardioprotective effects of YQHX. Transmission electron microscopy and Western blotting were used to observe apoptotic bodies and confirm protein expressions of key candidate targets, respectively.

RESULTS

Network pharmacology showed that a total of 141 potential targets were obtained from these databases. The functional analysis results revealed that the targets of YQHX were largely associated with apoptosis, and the PI3K-AKT and MAPK pathways might represent key functional pathways. The hub genes of network include ALB, TP53, AKT1, TNF, VEGFA, EGFR, MAPK1, CASP3, JUN, FN1, MMP9, and MAPK8. In vivo, YQHX significantly improved cardiac function and suppressed apoptosis in ischemic rat myocardium. Furthermore, YQHX could significantly upregulate Nrf2 and HO-1 expression, and inhibit JNK phosphorylation.

CONCLUSIONS

Based on network pharmacology and experimental evidence, this study proves that the cardioprotective effects and mechanisms of YQHX depend on multi-component, multi-target, and multi-pathway. In particular, YQHX exerts anti-apoptotic effects potentially by regulating the Nrf2/HO-1 and JNK-MAPK pathways.

Maackiain Protects the Kidneys of Type 2 Diabetic Rats via Modulating the Nrf2/HO-1 and TLR4/NF-κB/Caspase-3 Pathways

BACKGROUND

Type 2 diabetes (T2D) is aglobal health burden that accounts for about 90% of all cases of diabetes. Injury to the kidneys is aserious complication of type 2 diabetes. Maackiain, apterocarpan extracted from roots of Sophora flavescens, has been traditionally used for various disease conditions. However, nothing is known about its possible potential effect on HFD/STZ-T2D-induced nephrotoxicity.

METHODS

In this study, T2D rat model is created by high-fat diet (HFD) for 2 weeks with injection of asingle dose of streptozotocin (35mg/kg body weight). T2D rats were orally administered with maackiain (10 and 20mg/kg body weight) for 7 weeks.

RESULTS

Maackiain suppressed T2D-induced alterations in metabolic parameters, lipid profile and kidney functionality markers. By administering 10 and 20mg/kg maackiain to T2D rats, it was able to reduce lipid peroxidation while improving antioxidant levels (SOD, CAT, and GSH). Furthermore, the present study demonstrated the molecular mechanisms through which maackiain attenuated T2D-induced oxidative stress (mRNA: Nrf2, Nqo-1, Ho-1, Gclc and Gpx-1; protein: NRF2, NQO-1, HO-1 and NOX-4), inflammation (mRNA: Tlr, Myd88, IκBα, Mcp-1, Tgf-β, col4, Icam1, Vcam1 and E-selectin; Protein: TLR4, MYD88, NF-κB, IκBα, MCP-1; levels: TNF-α and MCP-1) and apoptosis (mRNA: Bcl-2, Bax, Bad, Apaf-1, Caspase-9 and Caspase-3; protein: Bcl-2, Bax, Caspase-3 and Caspase-9) mediated renal injury. Additionally, significant improvement in kidney architecture was observed after treatment of diabetic rats with 10 or 20mg/kg maackiain.

CONCLUSION

Maackiain protects the kidney by decreasing oxidative stress, inflammation, and apoptosis to preserve normal renal function in type 2 diabetes.

Phenethyl isothiocyanate attenuates diabetic nephropathy via modulation of glycative/oxidative/inflammatory signaling in diabetic rats

Diabetic nephropathy (DN) is a diabetic complication characterized by disruption of renal microvasculature, reactive oxygen species accumulation and increased inflammation, all of which contribute to renal injury. Phenethyl isothiocyanate (PEITC) is a naturally occurring isothiocyanate well known for its antioxidant and anti-inflammatory effects, yet its reno-preventive effects against DN has not been investigated. The current study looked into the in vivo reno-protective effects of PEITC in STZ-induced DN in rats. PEITC (3, 10 and 30 mg/kg) was administered orally for 8 weeks post DM establishment. PEITC treatment significantly improved kidney and liver functions, renal histopathological features, tissue fibrosis, macrophage infiltration and blood glucose levels compared to DN control. Mechanistically, PEITC treatment alleviated DN-induced renal damage via modulating glycation and oxidative stresses and inflammatory response. As such, PEITC activated glyoxalase 1 (GLO1) that induced a retraction in renal tissue expression of advanced glycation end products (AGEs) and its receptor (RAGE). PEITC activated nuclear erythroid 2-related factor 2 (Nrf2) and increased expression of its downstream targets, hemeoxygenase-1 (HO-1) and gamma glutamate-cysteine (γ-GCS). Additionally, PEITC treatment decreased the expression of Nrf2 repressor protein, keap1. The anti-inflammatory effect of PEITC was driven, at least in part, via reducing the NLRP3 inflammasome activation as indicated by down regulation of NLRP3, TXNIP, capsase-1 and IL-1β, TNF-alpha and IL-6. In conclusion; PEITC attenuated DN progression in a dose dependent manner mainly via interruption of AGE/RAGE and NLPR3/TXNIP/NrF2 crosstalk.

Geraniol isolated from lemon grass to mitigate doxorubicin-induced cardiotoxicity through Nrf2 and NF-κB signaling

BACKGROUND

Geraniol, a natural monoterpene, is a component of many plant essential oils. It contains many medicinal and pharmacological properties. Doxorubicin is an anticancer drug; however, its clinical usage is limited due to its cumulative and dose-dependent cardiotoxicity. This study investigates geraniol as a protective agent against doxorubicin-induced cardiotoxicity and explores possible underlying mechanisms of action.

METHODS

Male Sprague-Dawley rats were allocated into five groups. Groups 1 and 2 were administered saline and geraniol 200 mg/kg/day/orally, respectively, for 15 days. Group 3 was administered intraperitoneal doxorubicin (5 mg/kg/IP on the 5th, 10th and 15th days to achieve a cumulative dose of 15 mg/kg) to induce cardiotoxicity. The fourth and fifth groups were treated with either geraniol 100 mg/kg or 200 mg/kg orally and doxorubicin to equal the doxorubicin dose administered to Group 3.

RESULTS

Treatment with geraniol significantly ameliorated cardiac damage and restored serum cardiac injury marker levels in doxorubicin treated animals. Geraniol upregulated Nrf2 and HO-1 expression, elevated total antioxidant capacity, decreased the nuclear accumulation of kappa-light-chain enhancer of activated B cells (NF-κB), decreased the phosphorylation and degradation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα), suppressed tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin-18 (IL-18) levels, and restored the levels of Bax and caspase-3 and 9 in heart tissue.

CONCLUSION

Geraniol may function as a potential activator of nuclear factor erythroid 2-related factor 2 (Nrf2), which subsequently improves Nrf2-dependent antioxidative signaling, diminishes apoptosis and subdues the inflammatory response. The downstream result is protection of the heart from doxorubicin-induced cardiotoxicity.

Discovery of Novel Acetamide-Based Heme Oxygenase-1 Inhibitors with Potent In Vitro Antiproliferative Activity

Heme oxygenase-1 (HO-1) promotes heme catabolism exercising cytoprotective roles in normal and cancer cells. Herein, we report the design, synthesis, molecular modeling, and biological evaluation of novel HO-1 inhibitors. Specifically, an amide linker in the central spacer and an imidazole were fixed, and the hydrophobic moiety required by the pharmacophore was largely modified. In many tumors, overexpression of HO-1 correlates with poor prognosis and chemoresistance, suggesting the inhibition of HO-1 as a possible antitumor strategy. Accordingly, compounds 7i and 7l-p emerged for their potency against HO-1 and were investigated for their anticancer activity against prostate (DU145), lung (A549), and glioblastoma (U87MG, A172) cancer cells. The selected compounds showed the best activity toward U87MG cells. Compound 7l was further investigated for its in-cell enzymatic HO-1 activity, expression levels, and effects on cell invasion and vascular endothelial growth factor (VEGF) extracellular release. The obtained data suggest that 7l can reduce cell invasivity acting through modulation of HO-1 expression.

Resistance exercise affects catheter-related thrombosis in rats through miR-92a-3p, oxidative stress and the MAPK/NF-κB pathway

BACKGROUND

MiR-92a-3p and oxidative stress are associated with catheter-related thrombosis (CRT). As a kind of physical intervention, resistance exercise can effectively promote blood circulation. In this study, we investigated the roles of miR-92a-3p, oxidative stress and the P38 mitogen-activated protein kinase/nuclear factor-κB (MAPK/NF-κB) pathway in CRT during resistance exercise.

METHODS

The rat CRT model was used for resistance exercise intervention. Moreover, pathological changes from the right jugular vein to the right auricle were observed under an electron microscope. In addition, reactive oxygen species (ROS) production, malondialdehyde (MDA) activity and heme oxygenase (HO-1) level in rat serum were detected via ELISA. The expression levels of miR-92A-3p and HO-1 in the vascular tissues of the rats were determined via real-time quantitative PCR. Additionally, the expression levels of HO-1, NF-κB P65, p38MAPK and IκBa in the venous tissues of the rats were analysed by Western blot analysis.

RESULTS

The pathological results showed that the thrombosis incidence rate in the CRT + RE group was lower than that in the CRT group. In the CRT group, the expression levels of ROS and MDA, which are markers related to oxidative stress in serum, significantly increased whilst the expression of HO-1 decreased. In the venous tissue, the expression of miR-92a-3p increased, the level of HO-1 decreased, the levels of p38MAPK and NF-κB p65 significantly increased but that of P-IκBa and IκBa significantly decreased. In the CRT + RE group, after administering the resistance exercise intervention, ROS production and MDA activity in serum significantly decreased, the expression level of HO-1 increased and the expression level of miR-92a-3p in the venous tissues significantly decreased and was negatively correlated with that of HO-1. The levels of p38MAPK and NF-κB p65 significantly decreased but that of P- IκBa and IκBa significantly increased.

CONCLUSION

Resistance exercise intervention downregulated miR-92a-3p expression, repaired oxidative stress injury and prevented CRT formation.

Ashwagandha (Withania somnifera) root extract attenuates hepatic and cognitive deficits in thioacetamide-induced rat model of hepatic encephalopathy via induction of Nrf2/HO-1 and mitigation of NF-κB/MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Ashwagandha (ASH) is one of the medicinal plants used in traditional Indian, Ayurvedic, and Unani medicines for their broad range of pharmacological activities including, tonic, aphrodisiac, energy stimulant, and counteracting chronic fatigue. Besides, it is used in the treatment of nervous exhaustion, memory-related conditions, insomnia, as well as improving learning ability and memory capacity. ASH is preclinically proven to be efficient in hepatoprotection and improving cognitive impairment, however, its beneficial effects against hepatic encephalopathy (HE) is still unclear. Therefore, this study aimed at investigating the protective effects of ASH root extract against thioacetamide (TAA)-induced HE and delineate the underlying behavioral and pharmacological mechanisms.

MATERIALS AND METHODS

ASH metabolites were identified using UPLC-HRMS. Rats were pretreated with ASH (200 and 400 mg/kg) for 29 days and administrated TAA (i.p, 350 mg/kg) in a single dose. Then, behavioral (open field test, Y-maze, modified elevated plus maze and novel object recognition test), and biochemical (ammonia and hepatic toxicity indices) assessments, as well as oxidative stress markers (MDA and GSH) were evaluated. The hepatic and brain levels of glutamine synthetase (GS), nuclear factor erythroid 2-related factor 2 (Nrf2), heme-oxygenase (HO)-1, inducible nitric oxide synthase (iNOS) were detected by enzyme-linked immunosorbent assay (ELISA). The mRNA expressions of p38/ERK½ were determined using real-time polymerase chain reaction (PCR). Moreover, histopathological investigations and immunohistochemical (NF-κB and TNF-α immunohistochemical expressions) examinations were performed.

RESULTS

Metabolite profiling of ASH revealed more than 45 identified metabolites including phenolic acids, flavonoids and steroidal lactone triterpenoids. Compared to the TAA-intoxicated group, ASH improved the locomotor and cognitive deficits, serum hepatotoxicity indices and ammonia levels, as well as brain and hepatic histopathological alterations. ASH reduced hepatic and brain levels of MDA, GS, and iNOS, and increased their GSH, Nrf2, and HO-1 levels. Also, ASH downregulated p38 and ERK½ mRNA expressions, and NF-κB and TNF-α immunohistochemical expressions in brain and hepatic tissues.

CONCLUSIONS

Our results provided insights into the promising hepato- and neuroprotective effects of ASH, with superiority to 400 mg/kg ASH, to ameliorate HE with its sequential hyperammonemia and liver/brain injuries. This could be attributed to the recorded increase in the spontaneous alternation % and recognition index, antioxidant and anti-inflammatory activities, as well as upregulation of Nrf2 and downregualtion of MAPK signaling pathways.

Antioxidant mechanism exploration of the tripeptide Val-Asn-Pro generated from Jiuzao and its potential application in baijiu

Val-Asn-Pro (VNP) was identified from the raw material of baijiu distillation (Jiupei) and exhibit antioxidant activity in vitro. In this study, residue after baijiu distillation (Jiuzao) was used to seek the antioxidant peptide VNP with the methods reported inthe previous study. Its potential antioxidant mechanism in vivo was further assessed. Gene and protein expressions of Nrf2/Keap1-p38MAPK/PI3K-MafK signaling pathway and downstream enzymes (i.e., CAT, GPX1, SOD1, and HO-1) in AAPH-induced oxidative stress Sprague-Dawley (SD) rats were investigated. Influence of VNP on baijiu characteristics was also investigated. Based on the results, VNP was identified with a content of 5.25 mg/g Jiuzao. VNP significantly mitigated excess oxidative stress via activation of Nrf2/Keap1-p38MAPK/PI3K-MafK signaling pathway and activated downstream antioxidant enzymes. Furthermore, VNP showed unconspicuous influence on the flavor and taste of baijiu when added into baijiu and the content remained stable during storage. These results indicated that VNP is a potent antioxidant component isolated from Jiuzao that can be used in baijiu to enhance its antioxidant effect without affecting the main flavor and taste. The utilization of these functional components can also increase the added value of Jiuzao.

HMGB1-TIM3-HO1: A New Pathway of Inflammation in Skin of SARS-CoV-2 Patients? A Retrospective Pilot Study

The SARS-CoV-2 pandemic has completely disrupted the health systems of the entire planet. From the earliest months, it became increasingly clear that in addition to affecting the upper airways and lungs, there were other organs that could be affected. Among these, the skin became a real "sentinel signal" to be able to even suspect COVID-19. Background: this study deals with a little-explored issue for now: the study of skin immunopathology in SARS-CoV-2 positive subjects ascertained using the most reliable methods available. Methods: we used skin biopsy samples from SARS-CoV-2 positive and negative patients, studying morphology (Hematoxylin-Eosin), T lymphocyte population (CD4 and CD8), three markers such as HMGB-1, TIM-3 and HO-1 by immunohistochemistry. Results: although the presence of the CD4 and CD8 T population did not differ statistically significantly, we found greater activation and release of HMGB-1 in skin samples from SARS-CoV-2 positive patients, greater immunolabeling for TIM-3 at the level of CD4 and CD8 and a reduced expression of Heme oxygenase 1. Conclusions: these results support the possibility that there is immune deregulation in SARS-CoV-2 positive patients who develop skin manifestations of various kinds.

Arbutin attenuates ethanol-induced acute hepatic injury by the modulation of oxidative stress and Nrf-2/HO-1 signaling pathway

Alcoholic liver disease (ALD) is a pervasive ailment due to the excessive consumption of alcohol and there is no operative drug for its treatment. The current exploration was intended to examine the hepatoprotective efficacy of arbutin against ethanol-provoked liver injury in rats via the modulation of the Nrf-2/HO-1 signaling cascade. Wistar rats were challenged with the 3 g/kg/day (40% v/v) of ethanol for 4 weeks to provoke the ALD and concomitantly supplemented with 40 mg/kg of arbutin. The liver function markers enzymes, inflammatory cytokines, and oxidative stress markers levels were scrutinized by using the respective assay kits. The mRNA expression of Nrf-2/HO-1 signaling proteins was studied by reverse-transcription polymerase chain reaction. The histological alterations of liver tissues were examined. HepG2 cells were used for the in vitro studies. The levels of oxidative stress markers and liver marker enzymes were examined by using kits. Reactive oxygen species (ROS) and apoptotic cell death was detected by using fluorescent staining. There were no major differences in the body weight and liver weight of experimental animals. Arbutin treatment appreciably reduced the liver marker enzymes, upregulated superoxide dismutase, glutathione peroxidase, total antioxidant capacity, and the hydroxyl scavenging ability, and diminished the tumor necrosis factor-α and interleukin-6 levels in the serum of ethanol provoked animals. Arbutin triggered Nrf-2/HO-1 signaling cascade liver tissues of ethanol-provoked animals. Histological findings proved the preventing effects of arbutin. Arbutin did not demonstrate toxicity to the HepG2 cells. It reduced the aspartate aminotransferase and alanine aminotransferase, ROS, apoptotic cell death, lipid peroxidation and improved the antioxidants' levels in the ethanol-challenged HepG2 cells. In conclusion, our findings unveiled the hepatoprotective efficacy of arbutin against ethanol-provoked liver injury in rats. It could be a promising agent to treat alcoholic liver disease in the future.

κ Opioid Receptor Agonist Inhibits Myocardial Injury in Heart Failure Rats through Activating Nrf2/HO-1 Pathway and Regulating Ca2+-SERCA2a

OBJECTIVES

We aimed to observe the protective effect of κ opioid receptor (κ-OR) agonist on myocardial injury in heart failure (HF) rats and its effect on Ca2+-SERCA2a and to explore the regulatory mechanism with the Nrf2/HO-1 signaling pathway.

METHODS

50 Sprague-Dawley rats were randomly divided into the following groups: the sham operation group (sham group), HF model group (HF group), HF+κ-OR agonist U50488 group (HU group), HF+U50488H+novel calmodulin-dependent protein kinase II (CaMKII) agonist (oleic acid) (HUO group), and HF+U50488H+Nrf2 inhibitor (HUM group). The HF rat's model was established through surgical ligation of the left anterior descending coronary artery and the exhausting swimming exercise. After that, rat's cardiac function was monitored by echocardiography. HE and MASSON staining was used to detect the myocardial injury, and TUNEL staining was used to detect the myocardial apoptosis. ELISA was performed to detect the biomarkers of oxidative stress. Moreover, the distribution of reactive oxygen species (ROS) and Nrf2 was detected under immunofluorescence. The expression of sarco/endoplasmic reticulum calcium (Ca2+) ATPase (SERCA) 2a, calmodulin, endoplasmic reticulum stress- (ERS-) related proteins, and Nrf2/HO-1 signaling pathway-related proteins were detected by Western Blotting.

RESULTS

κ-OR agonist U50488H can significantly enhance rat's cardiac function, reduce the injury and apoptosis of myocardial cells, and alleviate endoplasmic reticulum stress injury in HF rats via upregulating the SERCA2a expression and inhibiting the Ca2+ influx. Furthermore, U50488H could also inhibit the phosphorylation of CaMKII and cAMP-response element binding protein (CREB). Additionally, administration of CaMKII-specific agonist could partially block the therapeutic effect of κ-OR agonist on the myocardium of HF rats. Interestingly, the antagonist of Nrf2 could also significantly reverse the therapeutic effect of κ-OR agonist. Therefore, these results suggested that the effect of U50488H on HF rats is dependent on regulating CaMKII phosphorylation and activating the Nrf2/HO-1 pathway.

CONCLUSION

κ-OR agonists U50488H can improve ERS in cardiomyocytes and relieve myocardial injury in HF rats through activating the Nrf2/HO-1 pathway and regulating Ca2+-SERCA2a to inhibit Ca2+ influx.

Protective effects and mechanisms of high-dose vitamin C on sepsis-associated cognitive impairment in rats

Sepsis survivors present long-term cognitive deficits. The present study was to investigate the effect of early administration of high-dose vitamin C on cognitive function in septic rats and explore its possible cerebral protective mechanism. Rat sepsis models were established by cecal ligation and puncture (CLP). Ten days after surgery, the Morris water maze test was performed to evaluate the behavior and cognitive function. Histopathologic changes in the hippocampus were evaluated by nissl staining. The inflammatory cytokines, activities of antioxidant enzymes (superoxide dismutase or SOD) and oxidative products (malondialdehyde or MDA) in the serum and hippocampus were tested 24 h after surgery. The activity of matrix metalloproteinase-9 (MMP-9) and expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1(HO-1) in the hippocampus were measured 24 h after surgery. Compared with the sham group in the Morris water maze test, the escape latency of sepsis rats was significantly (P = 0.001) prolonged in the navigation test, whereas the frequency to cross the platform and the time spent in the target quadrant were significantly (P = 0.003) reduced. High-dose vitamin C significantly decreased the escape latency (P = 0.01), but increased the time spent in the target quadrant (P = 0.04) and the frequency to cross the platform (P = 0.19). In the CLP+ saline group, the pyramidal neurons were reduced and distributed sparsely and disorderly, the levels of inflammatory cytokines of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 in the serum and hippocampus were significantly increased (P = 0.000), the blood brain barrier (BBB) permeability in the hippocampus was significantly (P = 0.000) increased, the activities of SOD in the serum and hippocampus were significantly (P = 0.000 and P = 0.03, respectively) diminished while the levels of MDA in the serum and hippocampus were significantly (P = 0.007) increased. High-dose vitamin C mitigated hippocampus histopathologic changes, reduced systemic inflammation and neuroinflammation, attenuated BBB disruption, inhibited oxidative stress in brain tissue, and up-regulated the expression of nuclear and total Nrf2 and HO-1. High-dose vitamin C significantly (P < 0.05) decreased the levels of tumor necrosis factor- (TNF)-α, interleukin-6 (IL-6), MDA in the serum and hippocampus, and the activity of MMP-9 in the hippocampus, but significantly (P < 0.05) increased the levels of SOD, the anti-inflammatory cytokine (IL-10) in the serum and hippocampus, and nuclear and total Nrf2, and HO-1 in the hippocampus. In conclusion, high-dose vitamin C can improve cognition impairment in septic rats, and the possible protective mechanism may be related to inhibition of inflammatory factors, alleviation of oxidative stress, and activation of the Nrf2/HO-1 pathway.

Activation of the Nrf2/HO-1 signaling pathway by dimethyl fumarate ameliorates complete Freund's adjuvant-induced arthritis in rats

The nuclear factor erythroid 2-related factor (Nrf2) signaling pathway has recently emerged as a novel therapeutic target in treating various diseases. Therefore, the present study aimed to assess the protective role of the Nrf2 activator, dimethyl fumarate (DMF) in the complete Freund's adjuvant (CFA)- induced arthritis model. DMF (25, 50, and 100 mg/kg) and dexamethasone (2 mg/kg) were orally administered for 14 days. Pain-related tests, paw volume, and arthritic scores were measured weekly. Serum TNF-α, IL-1β, cyclic citrullinated peptide (CCP), C-reactive protein (CRP), and rheumatoid factor (RF) levels were estimated. Nitrite, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), catalase (CAT), and myeloperoxidase (MPO) levels were also evaluated. NF-κB, Nrf2, HO-1, and COX-2 levels were estimated in the joint tissue. DMF treatment exerted anti-arthritic activity by enhancing the nociceptive threshold, improving arthritis scores, and reducing paw edema. Also, DMF suppressed changes in oxidative stress markers and inflammatory mediators and enhanced Nrf2 and HO-1 levels in CFA-injected rats. These findings indicate that the anti-arthritic activity of DMF may be mediated by the activation of the Nrf2/HO-1 pathway, which reduced oxidative damage and inflammation.

α7-nAChRs-mediated therapeutic angiogenesis accounts for the advantageous effect of low nicotine doses against myocardial infarction in rats

Angiogenesis accelerates tissue regeneration in a variety of ischemic conditions including myocardial infarction (MI). Here we tested the hypothesis that angiogenesis induced by α7-nicotinic acetylcholine receptors (α7-nAChRs) mitigates histopathological, electrocardiographic, and molecular consequences of MI in rats. These profiles were evaluated in the isoprenaline (85 mg/kg/day i. p. For 2 days) MI rat model treated with or without nicotine or PHA-543613 (PHA, selective α7-nAChR agonist). Isoprenaline-insulted rats showed (i) ECG signs of MI such as significant ST-segment elevations and prolonged QT-intervals, (ii) deteriorated left ventricular histopathological scoring and elevated inflammatory cell infiltration, (iii) reduced immunohistochemical expression of cardiac CD34, a surrogate marker of capillary density, (iv) decreased cardiac expression of iNOS and α7-nAChRs, and (v) adaptive increases in cardiac HO-1 expression and plasma angiogenic markers such as vascular endothelial growth factor (VEGF) and nitric oxide (NO). These effects of isoprenaline, except cardiac iNOS and α7-nAChRs downregulation, were ameliorated in rats treated with a low dose (20 μg/kg/day s. c. For 16 days) of nicotine or PHA. We also show that concurrent α7-nAChR blockade by methyllycaconitine (MLA, 40 μg/kg/day, for 16 days) reversed the ECG, histopathological, and capillary density effects of nicotine, thereby reinforcing the advantageous cardioprotective and anti-ischemic roles of α7-nAChRs in this setting. The observed results showed promising effects on isoprenaline induced myocardial damage. In conclusion, the activation of α7-nAChRs by doses of nicotine or PHA in the microgram scale promotes neovascularization and offers a promising therapeutic strategy for MI. CATEGORY: Cardiovascular Pharmacology.

Sevoflurane protects the liver from ischemia-reperfusion injury by regulating Nrf2/HO-1 pathway

We aimed to investigate the role and mechanism of sevoflurane (SEV) preconditioning in liver ischemia-reperfusion (I/R) injury. In vivo, rats were randomly divided into Sham group, I/R rat model group, I/R + SEV group and SEV group. In vitro, hypoxia-reoxygenation (H/R) cell model were established. Hematoxylin-Eosin (H&E) and TUNEL assay were used to evaluate the degree of tissue damage and detect apoptosis in rats, respectively. HO-1, nuclear Nrf2 and cytosolic Nrf2 expressions were detected by immunohistochemical staining, Western blot analysis and quantitative real-time PCR (qRT-PCR), respectively. Contents of Lactate dehydrogenase (LDH), malondialdehyde (MDA), and reactive oxygen species (ROS) were determined by corresponding kits. Inflammatory factor levels, cell viability, apoptosis were detected by enzyme-linked immunosorbent assay (ELISA), MTT assay, and flow cytometry, respectively.In the I/R group, liver damage was severe, apoptosis-positive cells were increased, HO-1 and nuclear Nrf2 expressions were increased, and cytosolic Nrf2 expression was decreased. After SEV pretreatment, the degree of liver injury and apoptosis in rats were significantly reduced, HO-1 and nuclear Nrf2 expressions were increased significantly, and cytosolic Nrf2 expression was decreased. 4% SEV had the best mitigating effect on H/R-induced liver cell damage, as evidenced by reduced contents of LDH and MDA, decreased inflammatory factors, a lowered apoptosis rate, inhibited ROS production, effectively promoted Nrf2 nucleation, and activated Nrf/HO-1 pathway. ML385 pretreatment significantly inhibited the effect of SEV on hepatocytes.Sevoflurane protects the liver from ischemia-reperfusion injury by regulating the Nrf2/HO-1 pathway.

Neuropathological and Cognitive Effects Induced by CuO-NPs in Rats and Trials for Prevention Using Pomegranate Juice

Copper oxide nanoparticles (CuO-NPs) are extensively utilized in several industries and in pharmaceutical production. This excess exposure elevates the concern about its expected poisonous impacts on humans and animals. Pomegranate juice (PJ) is a natural source of polyphenols and exhibits potent antioxidant activities. Our experiment intended to explore the neurobehavioral and toxicopathological impacts of CuO-NPs and to explain the mechanistic role of PJ to reduce their toxicity. Thirty Wistar albino rats received the subsequent materials through oral gavage, every day for 28d: (1) normal saline, (2) 3 mL/kg bwt PJ, (3) 6 mL/kg bwt PJ, (4) 300 mg/kg bwt CuO-NPs, (5) CuO-NPs + 3 mL/kg bwt PJ, (6) CuO-NPs + 6 mL/kg bwt PJ. Continuous exposure to CuO-NPs caused a significant elevation of MDA levels and reduction of total antioxidant capacity associated with remarkable pathological alterations in all brain regions including cerebrum, hippocampus and cerebellum. Progressive decline of memory along with cognitive and psychiatric disturbances were observed in rats exposed to CuO-NPs not in PJ co-treated rats. Continuous exposure to CuO-NPs caused over expression of the immunohistochemical markers of caspase-3, iNOS and GFAP altogether with DAN fragmentation and down-regulation of HO-1 and Nrf2 gene in the whole brain tissues. Conversely, rats co-treated with PJ showed dose dependent improvements in the entire toxicological, behavioral, and pathological parameters. We showed that PJ had the ability to reduce the oxidative stress damage via up-regulation of HO-1 and Nrf2 genes in the brain. So that PJ had the ability to protect the brain and DNA from further damage.

Protective effects of myrrh essential oil on isoproterenol-induced myocardial infarction in rats through antioxidant, anti-inflammatory, Nrf2/HO-1 and apoptotic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Myrrh, a traditional remedy, is the stem resinous exudate of Commiphora molmol Engler (Burseraceae). The aromatic yellowish-brown oleoresin has a long history in folk and traditional medicine, in Saudi Arabia and the Arab world. Severe universal concern attributable to the high mortality is Myocardial Infarction (MI). Acute administration of Isoproterenol (ISO) is an established animal model to induce myocardial injury.

OBJECTIVE

The existing animal study was outlined to inspect the actions of Myrrh essential oil on cardiac functional, antioxidant status, apoptotic and inflammatory deviations in isoproterenol induced MI.

MATERIALS AND METHODS

Normal and Myrrh control animals were administered normal saline and Myrrh essential oil for thirty days orally, respectively. On the 29th and 30th day, the animals were injected by saline (s.c.). In the ISO control, the animals were administered saline orally for 30 days and then confronted with ISO (85 mg/kg s.c.) on 29th and 30th days. In the Myrrh Groups (IV and V), the animals were treated with Myrrh essential oil (50 and 100 mg/k) respectively for 30 days and injected with ISO (85 mg/kg, s.c.) on 29th and 30th days.

RESULTS

Animals experienced MI displayed functional blood pressure deviations, intensification in the heart to body weight ratio, myocytes indicative markers (CK-MB, CPK, LDH, cTnT, cTnI), lipid peroxidation (MDA), protein expression of Nrf2 and HO-1, apoptotic markers (Caspase 3,9), and inflammatory indicators. Conversely, animals pre-treated with Myrrh revealed obliteration of those elevations triggered by ISO induction, diminished elevated biochemical values and improved heart function.

CONCLUSION

Myrrh abstain effective cardio-protective action in MI model through improving the oxidative condition with myocytes and abolishing apoptotic as well as inflammatory responses.

Leaf powder supplementation of Senna alexandrina ameliorates oxidative stress, inflammation, and hepatic steatosis in high-fat diet-fed obese rats

Obesity is an enduring medical issue that has raised concerns around the world. Natural plant extracts have shown therapeutic potential in preventing oxidative stress and inflammation related to obesity complications. In this study, Senna alexandrina Mill. leaves were utilized to treat high-fat diet-related metabolic disorders and non-alcoholic fatty liver diseases. Plasma biochemical assays were conducted to determine the lipid profiles and oxidative stress parameters, and the gene expression of antioxidant enzymes and inflammatory mediators was measured. Histological stained livers of high-fat diet-fed rats were observed. S. alexandrina leaf powder supplementation prevented the increase in cholesterol and triglyceride levels in high-fat diet-fed rats. Moreover, S. alexandrina leaves also reduced lipid peroxidation and nitric oxide production in these rats. Prevention of oxidative stress by S. alexandrina leaf supplementation in high-fat diet-fed rats is regulated by enhancing the antioxidant enzyme activity, followed by the restoration of corresponding gene expressions, such as NRF-2, HO-1, SOD, and CAT. Histological staining provides further evidence that S. alexandrina leaf supplementation prevents inflammatory cell infiltration, lipid droplet deposition, and fibrosis in the liver of high-fat diet-fed rats. Furthermore, this investigation revealed that S. alexandrina leaf supplementation controlled non-alcoholic fatty liver disease by modulating the expression of fat metabolizing enzymes in high-fat diet-fed rats. Therefore, S. alexandrina leaf supplementation inhibits fatty liver inflammation and fibrosis, suggesting its usefulness in treating non-alcoholic steatohepatitis. Thus, this natural leaf extract has potential in treatment of obesity related liver dysfunction.

Neuroprotection of Heme Oxygenase-2 in Mice AfterIntracerebral Hemorrhage

There are few effective preventive or therapeutic strategies to mitigate the effects of catastrophic intracerebral hemorrhage (ICH) in humans. Heme oxygenase is the rate-limiting enzyme in heme metabolism; heme oxygenase-2 (HO-2) is a constitutively expressed heme oxygenase. We explored the involvement of HO-2 in a collagenase-induced mouse model of ICH in C57BL/6 wild-type and HO-2 knockout mice. We assessed oxidative stress injury, blood-brain barrier permeability, neuronal damage, late-stage angiogenesis, and hematoma clearance using immunofluorescence, Western blot, MRI, and special staining methods. Our results show that HO-2 reduces brain injury volume and brain edema, alleviates cytotoxic injury, affects vascular function in the early stage of ICH, and improves hematoma absorbance and angiogenesis in the late stage of ICH in this model. Thus, we found that HO-2 has a protective effect on brain injury after ICH.

LC-MS characterized methanolic extract of zanthoxylum armatum possess anti-breast cancer activity through Nrf2-Keap1 pathway: An in-silico, in-vitro and in-vivo evaluation

ETHNOPHARMACOLOGICAL RELEVANCE

Zanthoxylum armatum DC (Rutaceae) containing flavonoids, alkaloids, coumarins, lignans, amides and terpenoid is well-known for its curative properties against various ailments including cancer. In the current research, phytochemicals present in the methanolic extract of Zanthoxylum armatum bark (MeZb) were characterized by LC-MS/MS analysis and chemotherapeutic potential of this extract was determined on DMBA-induced female Sprague Dawley rats.

MATERIALS AND METHODS

A simple and fast high-performance liquid chromatography-mass spectroscopy (LC-MS/MS) of MeZb was established followed by in-vitro antioxidant assays. This was followed by in-silico docking analysis as well as cytotoxicity assessment. Successively in-vivo study of MeZb was performed in DMBA-induced Sprague Dawley rats possessing breast cancer along with detailed molecular biology studies involving immunofluorescence, RT-qPCR and Western blot analysis.

RESULTS

LC-MS/MS investigation revealed the presence of compounds belonging to flavonoid, alkaloid and glycoside groups. MeZb revealed potential antioxidant activity in in-vitro antioxidant assays and strong binding energy of identified compounds was seen from the in-silico study with both HO1 and Keap1 receptor. Furthermore, the antioxidant action of MeZb was proven from the in-vivo analysis of antioxidant marker enzymes (lipid peroxidation, enzymic and non-enzymic antioxidants). This study also revealed upregulation of protective Nrf-2 following downregulation of Keap1 after MeZb treatment with respect to untreated cancerous rats.

CONCLUSION

These results exhibited anti-breast-cancer potential of MeZb through Nrf2-Keap1 pathway which may be due to the flavonoids, alkaloids and glycosides present in it.

Astilbin Protects Against Carbon Tetrachloride-Induced Liver Fibrosis in Rats

BACKGROUND

Hepatic fibrosis is an inflammatory liver disease, and there is no effective therapy at present. Astilbin is a bioactive ingredient found in many medicinal and food plants, with antioxidative, anti-inflammatory, and antitumor properties.

OBJECTIVES

This study aimed to investigate the protective effect and related molecular mechanism of astilbin against carbon tetrachloride (CCl4)-induced liver fibrosis in rats.

METHODS

Liver fibrosis was induced by injection of CCl4 in male Sprague-Dawley rats, and those rats were then treated with astilbin at different concentrations. Pathological changes, collagen production, inflammatory cytokine, and oxidative stress were evaluated to evaluate the effects of astilbin on CCl4-induced hepatic fibrosis. Real-time PCR and western blot were performed to detect the mRNA and protein expression of indicated genes.

RESULTS

We discovered that CCl4 caused significant fibrosis damage in rat liver, and astilbin dose-dependently improved the liver functions and fibrosis degree. Astilbin treatment significantly decreased collagen production, inflammatory response, and oxidative stress in vivo. Mechanically, administration of astilbin obviously elevated the hepatic levels of Nrf2 and its downstream components, including NAD(P)H:quinone oxidoreductase 1 (Nqo1), heme oxygenase (HO-1), glutamate-cysteine ligase catalytic subunit, and glutamate cysteine ligase modifier.

CONCLUSIONS

Taken together, these findings demonstrate that astilbin could protect against CCL4 induced-liver fibrosis in rats.

Hydrolyzed camel whey protein alleviated heat stress-induced hepatocyte damage by activated Nrf2/HO-1 signaling pathway and inhibited NF-κB/NLRP3 axis

Liver damage is the most severe complication of heat stress (HS). Hydrolyzed camel whey protein (CWP) possesses bioactive peptides with obviously antioxidant and anti-inflammatory activities. The current study aims to investigate whether CWP that is hydrolyzed by a simulated gastrointestinal digestion process, named S-CWP, protects BRL-3A hepatocytes from HS-induced damage via antioxidant and anti-inflammatory mechanisms. BRL-3A cells were pretreated with S-CWP before being treated at 43 °C for 1 h, and the levels of the cellular oxidative stress, inflammation, apoptosis, biomarkers for liver function, the activities of several antioxidant enzymes, and the cell viability were analyzed. The expression level of pivotal proteins in correlative signaling pathways was evaluated by western blotting. We confirmed that S-CWP alleviated HS-induced hepatocytes oxidative stress by decreased reactive oxygen species (ROS), nitric oxide (NO), 8-Hydroxy-2'-deoxyguanosine (8-OHdG), lipid peroxidation (LPO), protein carbonylation (PCO), and the activities of NADPH oxidase while enhanced superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), heme oxygenase-1 (HO-1) activities, and GSH content. S-CWP suppressed HS-induced inflammatory response by reducing the phosphorylation of NF-κB p65, the expression of NLRP3, and caspase-1 and finally alleviated caspase-3-mediated apoptosis. S-CWP also alleviated HS-induced hepatocyte injury by reducing alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels and restoring Heat Shock Protein 70 (HSP70) expression. Furthermore, S-CWP treatment significantly enhanced the expression of NF-E2-related nuclear factor erythroid-2 (Nrf2) and HO-1. The antioxidant and anti-inflammatory effects of S-CWP were weakened by ML385, a specific Nrf2 inhibitor. Additionally, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, significantly reversed S-CWP-induced reduction in the phosphorylation of NF-κB p65. Thus, our results revealed that S-CWP protected against HS-induced hepatocytes damage via activating the Nrf2/HO-1 signaling pathway and inhibiting NF-κB/NLRP3 axis.

[Antagonistic effect of modified Dahuang Zhechong Granule against the apoptosis of epididymal spermatogenic cells in varicocele rats based on Nrf2/HO-1 pathways]

OBJECTIVE

To investigate the effects of modified Dahuang Zhechong Granule (DZG) on the epididymal tissue of varicocele (VC) rats and the expressions of the nuclear factor erythroid 2 (NF-E2)-related factor (Nrf2) and heme oxygenase-1 (HO-1) protein.

METHODS

Sixty SD rats were randomly divided into six groups of an equal number: sham operation, VC model control, aescuven forte (AF) and low-, medium- and high-dose DZG. The VC model was established by ligation of the left renal vein with the Turner's method, followed by intragastrical administration of normal saline to the rats in the sham operation and VC model control groups, AF Tablets at 54 mg/kg to those in the AF group, and modified DZG at 0.6, 1.2 and 2.4 g/ml to those in the low-, medium- and high-dose DZG groups respectively, all once daily for 8 weeks. Then, all the animals were sacrificed and their left epididymides harvested for examination of semen quality, observation of local ultrastructural changes, measurement of the apoptosis of spermatogenic cells by Annexin V-FITC, and determination of the expressions of Nrf2 and HO-1 in the epididymal tissue by immunohistochemistry.

RESULTS

Evident pathological damage was observed in the left epididymal tissue of the VC model controls, with significantly reduced numbers of spermatogenic cells and sperm at all levels, partially destroyed cellular structure, and disappearance of some subcellular structures such as the lysosome, mitochondrion, endoplasmic reticulum, nucleus and cell membrane, which were all improved to some extent in the DZG and AF group. Sperm concentration and motility in the left epididymis were significantly higher in the medium- and high-dose DZG and AF groups than in the VC model controls (P < 0.05), even more significantly in the high-dose DZG than in the AF group (P < 0.05). The apoptosis rate of spermatogenic cells was markedly higher in the VC model control than in the sham operation group (P < 0.05), but lower in the medium- and high-dose DZG and AF groups than in the VC model controls (P < 0.05). Immunohistochemistry showed positive expressions of Nrf2 and HO-1 proteins, brown, scattered and with a low luminance of the cells, in the left epididymis tissue of the VC model control rats, but with a significantly higher cell luminance in the high-dose DZG and AF groups.

CONCLUSIONS

Modified Dahuang Zhechong Granule can effectively repair pathological damage to the epididymis of varicocele rats, increase the expressions of Nrf2 and HO-1 proteins, antagonize the apoptosis of spermatogenic cells and provide a favorable condition for sperm maturation.

Modulatory effect of Tagetes erecta flowers essential oils via Nrf2/HO-1/NF-κB/p65 axis mediated suppression of N-methyl-N'nitro-N-nitroguanidine (MNNG) induced gastric cancer in rats

Protective effect of Tagetes erecta flowers essential oils was investigated on oxidative stress, immune response, inflammation, and apoptosis against N-methyl-N'nitro-N-nitroguanidine (MNNG) induced gastric cancer in rats. Essential oil were extracted from Tagetes erecta flowers and analyzed using gas chromatography-mass spectrometry (GC-MS). For observing a protective effect against MNNG induced gastric cancer, we divided rats into 4 groups (group A to D) having 10 rats in each group. Performed various experiments and measured a different parameters to investigate antioxidant activity, immune response, anti-inflammatory and anti-apoptotic activity. The levels of malondialdehyde were markedly increased in the presence of N-methyl-N'nitro-N-nitroguanidine, whereas, the antioxidant activities of superoxide dismutase, and catalase were lowered in the treated rats in contrast with the control. Intervention with TEEO to gastric cancer-induced rats upregulated the redox status and the activity of the immune system to decrease cancer risk. The proinflammatory cytokines (IL-6 and TNF-α) secretions that were induced by MNNG were markedly inhibited by TEEO. Administration of TEEO also significantly reduced terminal deoxynucleotidyl transferase dUTP nick end labeling positive gastric cancer cells, expression of mRNA of caspase-3, and Bax. Whereas, the expression of Bcl-2 was increased. Additionally, downregulation of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and IκBα degradation and the nuclear factor-κB (NF-κB) p65 expression in tissues of the stomach of MNNG-induced-rats were markedly elevated due to TEEO. This suggested possession of TEEO with a protective shield against MNNG induced gastric cancer by the exertion of antioxidative stress, anti-apoptotic response, the anti-inflammatory response through Nrf2/HO-1, and NF-κB signaling pathways.

Effect of Nrf2 signaling pathway on the improvement of intestinal epithelial barrier dysfunction by hyperbaric oxygen treatment after spinal cord injury

Disruption of the intestinal epithelial barrier following spinal cord injury (SCI) seriously affect long-term quality of life. Oxidative stress-induced epithelial cells' injury contributes to the epithelial barrier dysfunction. Hyperbaric oxygen (HBO) treatment has been proved to alleviate SCI. However, it is unclear whether or not HBO treatment affects intestinal barrier function following SCI. In this study, our purpose was to explore the impact of HBO treatment on intestinal epithelial barrier function and underlying mechanisms following SCI. An SCI model was established in rats, and the rats received HBO treatment. Intestinal injury, mucosal permeability, intercellular junction proteins, and oxidative stress indicators were evaluated in our study. We found that HBO treatment significantly alleviated intestinal histological damage, reduced mucosal permeability, and markedly prevented bacterial translocation. Furthermore, HBO treatment significantly increased the expression of Claudin-1 and E-cadherin, inhibited intestinal tissue oxidative stress as demonstrated by upregulation of superoxide dismutase and glutathione, and HBO downregulated malondialdehyde. Mechanically, we demonstrated that HBO treatment ameliorated intestinal oxidative stress possibly through upregulating nuclear factor E2-related factor 2 (Nrf2) and its downstream targets, Heme oxygenase-1(HO-1), NADH-quinone oxidoreductase-1(NQO-1), and glutamate cysteine ligase catalytic subunit (GCLC). These results suggested that HBO treatment triggered antioxidative effects against intestinal epithelial barrier dysfunction by promoting Nrf2 signaling pathway after SCI.

Hormone Replacement Therapy and Aging: A Potential Therapeutic Approach for Age-Related Oxidative Stress and Cardiac Remodeling

Advanced age is an independent risk factor for cardiovascular diseases, which might be further exacerbated by estrogen deficiency. Hormone replacement therapy (HRT) decreases cardiovascular risks and events in postmenopausal women; however, its effects are not fully elucidated in older individuals. Thus, the aim of our study is to examine the impact of HRT on oxidant/antioxidant homeostasis and cardiac remodeling. In our experiment, control (fertile) and aging (~20-month-old) female Wistar rats were used. Aging rats were further divided into estrogen- (E2, 0.1 mg/kg/day per os) or raloxifene- (RAL, 1.0 mg/kg/day per os) treated subgroups. After 2 weeks of treatment, cardiac heme oxygenase (HO) activity, total glutathione (GSH) content, matrix metalloproteinase-2 (MMP-2) activity, and the concentrations of collagen type I and tissue inhibitor of metalloproteinase (TIMP-2), as well as the infarct size, were determined. The aging process significantly decreased the antioxidant HO activity and GSH content, altered the MMP-2/TIMP-2 signaling, and resulted in an excessive collagen accumulation, which culminated in cardiovascular injury. However, 2 weeks of either E2 or RAL treatment enhanced the antioxidant defense mechanisms and attenuated cardiac remodeling related to aging. Our findings clearly show that 2-week-long HRT is a potential intervention to bias successful cardiovascular aging via reducing oxidative damage and cardiovascular dysfunction.

Dimethyl fumarate protects against intestinal ischemia/reperfusion lesion: Participation of Nrf2/HO-1, GSK-3β and Wnt/β-catenin pathway

OBJECTIVE

Dimethyl fumarate (DMFU), a known Nrf2 activator, has proven its positive effect in different organs against ischemia/reperfusion (Is/Re) injury. Nevertheless, its possible impact to modulate intestinal Is/Re-induced injury has not been previously demonstrated before. Hence, this study aimed to investigate DMFU mechanistic maneuver against intestinal Is/Re.

METHODS

To accomplish this goal, Wistar rats were allocated into four groups; Sham-operated (SOP), intestinal Is/Re (1 h/6 h), and 14 days pre-treated DMFU (15 and 25 mg/kg/day, p.o).

RESULTS

The mechanistic maneuver divulged that DMFU safeguarded the intestine partly via amplifying the expression/content of Nrf2 along with enhancing its downstream, HO-1 expression/content. In addition, DMFU lessened GSK-3β expression/content accompanied by enriching β-catenin expression/content. The antioxidant action was affirmed by enhancing total antioxidant capacity, besides reducing MDA, iNOS, and its by-product, NOx. The DMFU action entailed anti-inflammatory character manifested by down-regulation of expression/content NF-κB with subsequent rebating the contents of TNF-α, IL-1β, and P-selectin, as well as MPO activity. Moreover, DMFU had anti-apoptotic nature demonstrated through enriching Bcl-2 level and diminishing that of caspase-3.

CONCLUSION

DMFU purveyed tenable novel protective mechanisms and mitigated events associated with intestinal Is/Re mischief either in the lower or the high dose partly by amending of oxidative stress and inflammation through the modulation of Nrf2/HO-1, GSK-3β, and Wnt/β-catenin pathways.

Activation of autophagy and suppression of apoptosis by dapagliflozin attenuates experimental inflammatory bowel disease in rats: Targeting AMPK/mTOR, HMGB1/RAGE and Nrf2/HO-1 pathways

Dapagliflozin, a selective sodium-glucose co-transporter 2 (SGLT2) inhibitor, has featured marked anti-inflammatory effects in murine models of myocardial infarction, renal injury, and neuroinflammation. Yet, its potential impact on the pathogenesis of inflammatory bowel diseases (IBD) has not been previously investigated. The presented study aimed to explore the prospect of dapagliflozin to mitigate 2,4,6 trinitrobenzene sulfonic acid (TNBS)-induced rat colitis model which recapitulates several features of the human IBD. The molecular mechanisms pertaining to the dynamic balance between autophagy/apoptosis and colon injury were delineated, particularly, AMPK/mTOR, HMGB1/RAGE/NF-κB and Nrf2/HO-1 pathways. The colon tissues were examined using immunoblotting, ELISA, and histopathology. Dapagliflozin (0.1, 1 and 5 mg/kg; p.o.) dose-dependently mitigated colitis severity as manifested by suppression of the disease activity scores, macroscopic damage scores, colon weight/length ratio, histopathologic perturbations, and inflammatory markers. More important, dapagliflozin enhanced colonic autophagy via upregulating Beclin 1 and downregulating p62 SQSTM1 protein expression. In this context, dapagliflozin activated the AMPK/mTOR pathway by increasing the p-AMPK/AMPK and lowering the p-mTOR/mTOR ratios, thereby, favoring autophagy. Moreover, dapagliflozin dampened the colonic apoptosis via lowering the caspase-3 activity, cleaved caspase-3 expression, and Bax/Bcl-2 ratio. Furthermore, dapagliflozin attenuated the HMGB1/RAGE/NF-κB pathway via lowering HMGB1, RAGE, and p-NF-κBp65 protein expression. Regarding oxidative stress, dapagliflozin lowered the oxidative stress markers and augmented the Nrf2/HO-1 pathway. Together, the present study reveals, for the first time, the ameliorative effect of dapagliflozin against experimental colitis via augmenting colonic autophagy and curbing apoptosis through activation of AMPK/mTOR and Nrf2/HO-1 pathways and suppression of HMGB1/RAGE/NF-κB cascade.

SLC30A7 has anti-oxidant stress effects in high glucose-induced apoptosis via the NFE2L2/HMOX1 signal transduction pathway

AIMS

Apoptosis and oxidant stress are known to be involved in the pathogenesis of diabetic kidney disease (DKD). We have previously reported that zinc transporter 7 in SLC30 family (SLC30A7) inhibits apoptosis in rat peritoneal mesothelial cells under high glucose (HG) conditions. In the current study, we aimed to investigate whether SLC30A7 had effect for anti-oxidant stress in renal tubular epithelial cells under HG.

METHODS

SLC30A7 in HG-induced apoptosis in a normal rat kidney tubular epithelial cell line (NRK-52E cells)/kidneys of STZ-induced diabetic mice was examined and the activity of nuclear factor erythroid 2-related factor 2 (NFE2L2) was further analyzed by using real time RT-PCR, siRNA and Western blot protocols.

RESULTS

SLC30A7 was found to be up-regulated, while NFE2L2 was activated in kidneys of STZ-induced diabetic mice and HG-induced apoptosis of NRK-52E cells. Knock-down of SLC30A7 with siRNA protocol resulted in lower intracellular free zinc levels in the cells and decreased zinc distribution in the Golgi apparatus. Furthermore, knock-down of NFE2L2 down-regulated its target HMOX1 gene expression, decreased SLC30A7 activity but increased HG-induced apoptosis.

CONCLUSION

The current study provides new evidence that SLC30A7 has anti-oxidant stress effects in HG-induced apoptosis via the NFE2L2/HMOX1 signal transduction pathway.

The renoprotective effects of Heme Oxygenase-1 during contrast-induced acute kidney injury in preclinical diabetic models

OBJECTIVES

Contrast-induced acute kidney injury (CI-AKI) is an important clinical problem that can be aggravated by diabetes mellitus, a major risk factor. However, heme oxygenase-1 (HO-1), a promising therapeutic target, can exert antioxidant effects against CI-AKI. Thus, we investigated the role of HO-1 in CI-AKI in the presence of diabetes mellitus.

METHODS

Twenty-eight male Wistar rats weighing 250-300g were subjected to left uninephrectomy, and concomitantly, diabetes induced by streptozotocin (65 mg/kg). After 12 weeks, iodinated contrast (meglumine ioxithalamate, 6 mL/kg) and hemin (HO-1 inducer-10 mg/k) were administered 60 min before iodinated contrast treatment. The rats were randomly divided into four groups: control, diabetes mellitus (DM), DM iodinated contrast (DMIC), and DMIC hemin (DMICH). Kidney function, albuminuria, oxidative profile, and histology were assessed. All experimental data were subjected to statistical analyses.

RESULTS

CI-AKI in preclinical diabetic models decreased creatinine clearance and increased urinary neutrophil gelatinase-associated lipocalin (NGAL) levels and the degree of albuminuria. Additionally, the levels of oxidative and nitrosative stress metabolites (urinary peroxides, thiobarbituric acid-reactive substances, and NO) were elevated, while thiol levels in kidney tissue were reduced. Kidney histology showed tubular cell vacuolization and edema. HO-1 inducer treatment improved kidney function and reduced urinary the NGAL levels. The oxidative profile showed an increase in the endogenous thiol-based antioxidant levels. Additionally, the tubular injury score was reduced following HO-1 treatment.

CONCLUSIONS

Our findings highlight the renoprotective effects of HO-1 in CI-AKI and preclinical diabetic models. Therefore, HO-1 ameliorates kidney dysfunction, reduces oxidative stress, and prevents cell necrosis.

Immune Modulation by Inhibitors of the HO System

The heme oxygenase (HO) system involves three isoforms of this enzyme, HO-1, HO-2, and HO-3. The three of them display the same catalytic activity, oxidating the heme group to produce biliverdin, ferrous iron, and carbon monoxide (CO). HO-1 is the isoform most widely studied in proinflammatory diseases because treatments that overexpress this enzyme promote the generation of anti-inflammatory products. However, neonatal jaundice (hyperbilirubinemia) derived from HO overexpression led to the development of inhibitors, such as those based on metaloproto- and meso-porphyrins inhibitors with competitive activity. Further, non-competitive inhibitors have also been identified, such as synthetic and natural imidazole-dioxolane-based, small synthetic molecules, inhibitors of the enzyme regulation pathway, and genetic engineering using iRNA or CRISPR cas9. Despite most of the applications of the HO inhibitors being related to metabolic diseases, the beneficial effects of these molecules in immune-mediated diseases have also emerged. Different medical implications, including cancer, Alzheimer´s disease, and infections, are discussed in this article and as to how the selective inhibition of HO isoforms may contribute to the treatment of these ailments.

Therapeutic Potential of Carbon Monoxide (CO) and Hydrogen Sulfide (H2S) in Hemolytic and Hemorrhagic Vascular Disorders-Interaction between the Heme Oxygenase and H2S-Producing Systems

Over the past decades, substantial work has established that hemoglobin oxidation and heme release play a pivotal role in hemolytic/hemorrhagic disorders. Recent reports have shown that oxidized hemoglobins, globin-derived peptides, and heme trigger diverse biological responses, such as toll-like receptor 4 activation with inflammatory response, reprogramming of cellular metabolism, differentiation, stress, and even death. Here, we discuss these cellular responses with particular focus on their mechanisms that are linked to the pathological consequences of hemorrhage and hemolysis. In recent years, endogenous gasotransmitters, such as carbon monoxide (CO) and hydrogen sulfide (H₂S), have gained a lot of interest in connection with various human pathologies. Thus, many CO and H₂S-releasing molecules have been developed and applied in various human disorders, including hemolytic and hemorrhagic diseases. Here, we discuss our current understanding of oxidized hemoglobin and heme-induced cell and tissue damage with particular focus on inflammation, cellular metabolism and differentiation, and endoplasmic reticulum stress in hemolytic/hemorrhagic human diseases, and the potential beneficial role of CO and H₂S in these pathologies. More detailed mechanistic insights into the complex pathology of hemolytic/hemorrhagic diseases through heme oxygenase-1/CO as well as H₂S pathways would reveal new therapeutic approaches that can be exploited for clinical benefit.

Natural Product Heme Oxygenase Inducers as Treatment for Nonalcoholic Fatty Liver Disease

Heme oxygenase (HO) is a critical component of the defense mechanism to a wide variety of cellular stressors. HO induction affords cellular protection through the breakdown of toxic heme into metabolites, helping preserve cellular integrity. Nonalcoholic fatty liver disease (NAFLD) is a pathological condition by which the liver accumulates fat. The incidence of NAFLD has reached all-time high levels driven primarily by the obesity epidemic. NALFD can progress to nonalcoholic steatohepatitis (NASH), advancing further to liver cirrhosis or cancer. NAFLD is also a contributing factor to cardiovascular and metabolic diseases. There are currently no drugs to specifically treat NAFLD, with most treatments focused on lifestyle modifications. One emerging area for NAFLD treatment is the use of dietary supplements such as curcumin, pomegranate seed oil, milk thistle oil, cold-pressed Nigella Satvia oil, and resveratrol, among others. Recent studies have demonstrated that several of these natural dietary supplements attenuate hepatic lipid accumulation and fibrosis in NAFLD animal models. The beneficial actions of several of these compounds are associated with the induction of heme oxygenase-1 (HO-1). Thus, targeting HO-1 through dietary-supplements may be a useful therapeutic for NAFLD either alone or with lifestyle modifications.

Heme oxygenase-2 is post-translationally regulated by heme occupancy in the catalytic site

Heme oxygenase-2 (HO2) and -1 (HO1) catalyze heme degradation to biliverdin, CO, and iron, forming an essential link in the heme metabolism network. Tight regulation of the cellular levels and catalytic activities of HO1 and HO2 is important for maintaining heme homeostasis. HO1 expression is transcriptionally regulated; however, HO2 expression is constitutive. How the cellular levels and activity of HO2 are regulated remains unclear. Here, we elucidate the mechanism of post-translational regulation of cellular HO2 levels by heme. We find that, under heme-deficient conditions, HO2 is destabilized and targeted for degradation, suggesting that heme plays a direct role in HO2 regulation. HO2 has three heme binding sites: one at its catalytic site and the others at its two heme regulatory motifs (HRMs). We report that, in contrast to other HRM-containing proteins, the cellular protein level and degradation rate of HO2 are independent of heme binding to the HRMs. Rather, under heme deficiency, loss of heme binding to the catalytic site destabilizes HO2. Consistently, an HO2 catalytic site variant that is unable to bind heme exhibits a constant low protein level and an enhanced protein degradation rate compared with the WT HO2. Finally, HO2 is degraded by the lysosome through chaperone-mediated autophagy, distinct from other HRM-containing proteins and HO1, which are degraded by the proteasome. These results reveal a novel aspect of HO2 regulation and deepen our understanding of HO2's role in maintaining heme homeostasis, paving the way for future investigation into HO2's pathophysiological role in heme deficiency response.

Melatonin Suppresses Ferroptosis Induced by High Glucose via Activation of the Nrf2/HO-1 Signaling Pathway in Type 2 Diabetic Osteoporosis

Ferroptosis is recently identified, an iron- and reactive oxygen species- (ROS-) dependent form of regulated cell death. This study was designed to determine the existence of ferroptosis in the pathogenesis of type 2 diabetic osteoporosis and confirm that melatonin can inhibit the ferroptosis of osteoblasts through activating Nrf2/HO-1 signaling pathway to improve bone microstructure in vivo and in vitro. We treated MC3T3-E1 cells with different concentrations of melatonin (1, 10, or 100 μM) and exposed them to high glucose (25.5 mM) for 48 h in vitro. Our data showed that high glucose can induce osteoblast cytotoxicity and the accumulation of lipid peroxide, the mitochondria of osteoblast show the same morphology changes as the erastin treatment group, and the expression of ferroptosis-related proteins glutathione peroxidase 4 (GPX4) and cystine-glutamate antiporter (SLC7A11) is downregulated, but these effects were reversed by ferroptosis inhibitor ferrastatin-1 and iron chelator deferoxamine (DFO). Furthermore, western blot and real-time polymerase chain reaction were used to detect the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1); osteogenic capacity was evaluated by alizarin red S staining and the expression of osteoprotegerin, osteocalcin, and alkaline phosphatase; the results showed that the expression levels of these proteins in osteoblasts with 1, 10, or 100 μM melatonins were significantly higher than the high glucose group, but after using Nrf2-SiRNA interference, the therapeutic effect of melatonin was significantly inhibited. We also performed in vivo experiments in a diabetic rat model treated with two concentrations of melatonin (10, 50 mg/kg). Dynamic bone histomorphometry and micro-CT were used to observe the rat bone microstructure, and the expression of GPX4 and Nrf2 was determined by immunohistochemistry. Here, we first report that high glucose induces ferroptosis via increased ROS/lipid peroxidation/glutathione depletion in type 2 diabetic osteoporosis. More importantly, melatonin significantly reduced the level of ferroptosis and improved the osteogenic capacity of MC3T3-E1 through activating the Nrf2/HO-1 pathway in vivo and in vitro.

Soy isoflavones ameliorate the cognitive dysfunction of Goto-Kakizaki rats by activating the Nrf2-HO-1 signalling pathway

Soy isoflavones (SIF) are soybean phytochemicals that are considered to be biologically active components that protect from neurodegenerative diseases. In this study, the therapeutic effect of SIF was evaluated in a diabetic Goto-Kakizaki (GK) rat model. Twenty male GK rats were randomly divided into diabetes mellitus (DM) model group and SIF+DM group (n=10 in each group). Twenty age-matched male Wistar rats were randomly divided into control group (CON group) and CON+SIF group, with 10 rats in each group. The learning and memory functions of the animals were determined by the Morris water maze (MWM) test. Hematoxylin-eosin staining (HE) was performed to examine pyramidal neuron loss in the CA1 area of the hippocampus. Markers of oxidative stress (OS) were measured to evaluate oxidative stress-mediated injury. RT-PCR and western blotting were used to analyze the expression of nuclear factorerythroid2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1) and NAD(P)H dehydrogenase quinone1 (NQO1). Treatment with SIF for 4 weeks alleviated the cognitive dysfunction of the GK rats as determined by the MWM test. Moreover, SIF treatment also reduced diabetes-related oxidative reactions. In addition, SIF enhanced the expression of Nrf2, HO-1 and NQO1, suggesting a potential antioxidation mechanism for the effect of SIF. These findings suggest that SIF can be considered candidates for inhibiting the progression of diabetes-induced cognitive dysfunction, provide novel insights into the antioxidant effect of SIF and further strengthen the link between oxidative stress and diabetes.

Chemo-preventive effect of crocin against experimentally-induced hepatocarcinogenesis via regulation of apoptotic and Nrf2 signaling pathways

The results of the current study investigated the chemo-preventive effect of crocin against hepatocarcinogenesis in rats with particular focus on the evaluation of the modulatory impact of crocin on apoptotic and nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways. Thioacetamide (TAA) (200 mg/kg, I.P.) was used for experimental induction of hepatocarcinogenesis in rats. Crocin administration significantly attenuated TAA-induced cancerous lesions with concomitant attenuation of impaired liver functions. This was associated with significant enhancement in hepatic Nrf2 and heme oxygenase-1 (HO-1) expression with parallel suppression in Keap-1 expression. Inline, crocin induced a significant improvement in hepatic oxidative status with enhanced antioxidant batteries. Crocin administration significantly suppressed the hepatic content of c-Jun N-terminal kinase (c-JNK) with significant upregulation in TNF-related apoptosis-inducing ligand (TRAIL) and caspase-8 protein expression as well as p53 gene expression; biomarkers of apoptosis. Moreover, hepatic expression of the apoptotic BAX significantly increased and the anti-apoptotic Bcl-2 significantly decreased in the liver specimen; biomarkers of intrinsic apoptosis. In conclusion; crocin attenuates experimentally induced hepato-carcinogenesis via modulation of oxidative/apoptotic signaling. Namely, crocin induced hepatic expression of Nrf2 with downstream modulation of endogenous HO-1 and Keap-1 signaling with modulation of various key players of apoptosis including; c-JNK, p53, TRAIL, caspase-8, BAX, and Bcl-2.

Astragaloside IV ameliorates preeclampsia-induced oxidative stress through the Nrf2/HO-1 pathway in a rat model

Preeclampsia (PE) can cause serious health problems for pregnant women and their infants. Astragaloside IV has been shown to exert cardioprotective, anti-inflammatory, and antioxidative effects on various disorders. We aimed to study the effects of Astragaloside IV on PE symptoms using an N^G-nitro-l-arginine methyl ester (l-NAME)-induced rat model of PE. The pregnant rats' physiological features, including blood pressure, urine protein, serum soluble fms-like tyrosine kinase-1(sFlt-1)/placental growth factor (PlGF) ratio, and weight of placenta, as well as the weight, length, and survival of pups, were documented. The expression levels of target genes were analyzed by Western blot and qRT-PCR assays. The levels of target secreted proteins were determined by ELISA. We demonstrated that the administration of Astragaloside IV might exert a multitude of beneficial effects on attenuated PE symptoms in a rat model of PE. We further revealed that the effects of Astragaloside IV on PE rats were achieved, at least partially, through elimination of oxidative stress and stimulation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. Our study indicated that Astragaloside IV may serve as a promising candidate for the development of new therapeutic methods for patients with PE.

Spatholobi Caulis dispensing granule reduces deep vein thrombus burden through antiinflammation via SIRT1 and Nrf2

BACKGROUND

Deep vein thrombosis (DVT) is a kind of blood stasis syndrome. Spatholobi Caulis (SC) has been widely used for the treatment of blood stasis syndrome in China, but the underlying mechanism remains poorly understood.

PURPOSE

The aim of present study was to investigate the anti-DVT mechanism of Spatholobi Caulis dispensing granule (SCDG).

STUDY DESIGN/METHODS

A rat model of inferior vena cava (IVC) stenosis-induced DVT and a cell model of oxygen-glucose deprivation (OGD) were performed. Rats were orally administered with SCDG solution once daily for seven consecutive days. IVC stenosis-induced DVT was operated on the sixth day. Thrombi were harvested and weighed on the seventh day. Pathological changes were observed by hematoxylin-eosin (HE) staining. Tumor necrosis factor (TNF)-α and interleukin (IL)-1β of serum were analyzed by enzyme-linked immunosorbent assay. C-reactive protein (CRP) was measured with turbidimetric immunoassay. Protein expressions in thrombosed IVCs and/or OGD-stimulated EA. hy926 cells were evaluated by western blot and/or immunofluorescence analyses.

RESULTS

SCDG dramatically decreased thrombus weight. SCDG decreased tissue factor (TF) protein expression, inflammatory cells influxes in thrombosed vein wall and serum levels of inflammatory cytokines and CRP. Further, SCDG up-regulated Sirtuin 1 (SIRT1) protein expression and down-regulated acetylated-NF-κB p65 (Ace-p65) protein expression. Moreover, SCDG up-regulated nuclear factor-erythroid 2 related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) protein expressions, and down-regulated phosphorylated-NF-κB p65 (p-p65) protein expression. In the OGD cell model, SCDG medicated serum decreased the protein expression of TF. SCDG medicated serum enhanced SIRT1 protein expression and reduced Ace-p65 nuclear protein expression. SCDG medicated serum promoted protein expressions of nuclear Nrf2 and total HO-1, and inhibited translocation of p65. Furthermore, inhibiting SIRT1 and Nrf2 reversed the protective effect of SCDG medicated serum on OGD-induced EA. hy926 cells.

CONCLUSION

SCDG may prevent DVT through antiinflammation via SIRT1 and Nrf2.

Umbelliferone Inhibits Spermatogenic Defects and Testicular Injury in Lead-Intoxicated Rats by Suppressing Oxidative Stress and Inflammation, and Improving Nrf2/HO-1 Signaling

INTRODUCTION

Lead (Pb) is an environmental toxic metal that threatens human health. Umbelliferone (UMB) is a coumarin with known medicinal and protective properties against cytotoxicity. This study explored the ameliorative effect of UMB against Pb-induced testicular toxicity in rats, focusing on steroidogenesis, oxidative stress and inflammation.

MATERIALS AND METHODS

Rats received lead acetate (50 mg/kg) and UMB (25, 50 or 100 mg/kg) via oral gavage for 4 weeks.

RESULTS

Pb-intoxicated rats exhibited testicular tissue injury and decreased serum levels of LH, FSH and testosterone. The count, viability, motility and normal morphology of the sperms were decreased accompanied with downregulated steroidogenesis markers in Pb-induced group. UMB prevented testicular injury, increased serum levels of LH, FSH and testosterone, upregulated steroidogenesis markers and improved the semen quality. In addition, UMB attenuated oxidative stress and oxidative DNA damage, downregulated the expression of pro-inflammatory mediators and Bax, boosted antioxidant defenses and Bcl-2, and upregulated Nrf2/HO-1 signaling in Pb-intoxicated rats.

CONCLUSION

UMB prevents Pb-induced testicular injury by suppressing oxidative damage, inflammation and cell death, and boosting antioxidant defenses, Nrf2/HO-1 signaling and pituitary-gonadal axis. Thus, UMB may represent a protective and cost-effective agent against Pb testicular toxicity, pending further investigations to elucidate other underlying mechanisms.

Heme Oxygenase 1 and 2 Differentially Regulate Glucose Metabolism and Adipose Tissue Mitochondrial Respiration: Implications for Metabolic Dysregulation

Heme oxygenase (HO) consists of inducible (HO-1) and constitutive (HO-2) isoforms that are encoded by Hmox1 and Hmox2 genes, respectively. As an anti-inflammatory and antioxidant molecule, HO participates in the development of metabolic diseases. Whether Hmox deficiency causes metabolic abnormalities under basal conditions remains unclear. We hypothesized that HO-1 and HO-2 differentially affect global and adipose tissue metabolism. To test this hypothesis, we determined insulin sensitivity, glucose tolerance, energy expenditure, and respiratory exchange ratio in global Hmox1^-/- and Hmox2^-/- mice. Body weight was reduced in female but not male Hmox1^-/- and Hmox2^-/- mice. Reduced insulin sensitivity and physical activity were observed in Hmox1^-/- but not Hmox2^-/- mice. Deletion of either Hmox1 or Hmox2 had no effects on glucose tolerance, energy expenditure or respiratory exchange ratio. Mitochondrial respiration was unchanged in gonadal fat pads (white adipose tissue, WAT) of Hmox1^-/- mice. Hmox2 deletion increased proton leak and glycolysis in gonadal, but not interscapular fat tissues (brown adipose tissue, BAT). Uncoupling protein and Hmox1 genes were unchanged in gonadal fat pads of Hmox2^-/- mice. Conclusively, HO-1 maintains insulin sensitivity, while HO-2 represses glycolysis and proton leak in the WAT under basal condition. This suggests that HO-1 and HO-2 differentially modulate metabolism, which may impact the metabolic syndrome.

Consumption of Anacardium Occidentale L. (Cashew Nuts) Inhibits Oxidative Stress through Modulation of the Nrf2/HO-1 and NF-kB Pathways

Ischemia/reperfusion injury is a severe disorder associated with a high mortality. Several antioxidant and pharmacological properties of cashew nuts (Anacardium occidentale L.) and its metabolites from different countries have recently been described. It is a medicinal plant with important therapeutic effects. This study aimed to verify the effect of an oral administration of cashew nuts in a rat model of ischemia/reperfusion (I/R). Adult male rats were subjected to intestinal I/R injury by clamping the superior mesenteric artery for 30 min and then allowing animals to 1 h of reperfusion. Rats subjected to I/R of the gut showed a significant increase in different biochemical markers. In particular, we evaluated lipid peroxidation, tissue myeloperoxidase activity, protein carbonyl content, reactive oxygen species generation and decreased antioxidant enzyme activities. Western blot analysis showed the activation of the NRF2 and NF-kB pathways. Increased immunoreactivity to nitrotyrosine, PARP, P-selectin, and ICAM-1 was observed in the ileum of rats subjected to I/R. Administration of cashew nuts (100 mg/kg) significantly reduced the mortality rate, the fall in arterial blood pressure, and oxidative stress and restored the antioxidant enzyme activities by a mechanism involving both NRF2 and NF-kB pathways. Cashew nuts treatments reduced cytokines plasma levels, nitrotyrosine, and PARP expression as well as adhesion molecules expressions. Additionally, cashew nuts decreased the intestinal barrier dysfunction and mucosal damage, the translocation of toxins and bacteria, which leads to systemic inflammation and associated organs injuries in particular of liver and kidney. Our study demonstrates that cashew nuts administration exerts antioxidant and pharmacological protective effects in superior mesenteric artery occlusion–reperfusion shock.

Effect of Polydatin on Neurological Function and the Nrf2 Pathway during Intracerebral Hemorrhage

This study investigates the effect of polydatin on the neurological function of cerebral hemorrhage rats and on the Nrf2 pathway of the endogenous antioxidant system in tissues around cerebral hematoma. Further, the study also aims to provide solid insights for clinical diagnosis and treatment. A total of 54 SPF grade male Wistar rats were divided into three groups: the sham group, model group, and polydatin group. Various parameters such as neurological deficit score, brain water content, pathological morphology, oxidative stress index content, Nrf2, NQO1, HO-1 mRNA expression, and the expression of HO-1, Nrf2, and kelch-like epichlorohydrin-1 (Keap1) protein were observed. Compared with the sham group, the mNSS score and brain water content of rats in the model group increased significantly after dosing (P < 0.05). When compared with the model group, the mNSS score and brain water content of rats in the polydatin group decreased significantly after dosing (P < 0.05). Compared with the other group, the serum NSE content of rats in the polydatin group decreased (P < 0.05). An increase was observed in the contents of NO, SOD, MDA, GSSG, and GSH in the brain tissue of rats in the model group when compared with the sham group. Compared with the model group, the contents of NO and MDA in the brain tissue of rats in the polydatin group decreased, while the contents of SOD, GSSG, and GSH increased (P < 0.05). The relative expressions of Nrf2, NQO1, and HO-1mRNA in the brain tissue of rats in the polydatin group was relatively high compared with both groups (P < 0.05). Polydatin can improve the neurological function of ICH rats and reduce the oxidative stress response by regulating the Nrf2-ARE pathway and downstream gene expression. This study preliminarily discussed the relevant mechanism of polydatin in the treatment of ICH rats, thus providing a theoretical reference to ICH treatment.

Nrf2/HO-1 mediates the neuroprotective effects of pramipexole by attenuating oxidative damage and mitochondrial perturbation after traumatic brain injury in rats

Pramipexole (PPX), a D2-like receptor agonist, is generally used in the treatment of Parkinson's disease and restless leg syndrome. Its neuroprotective effects have been shown against various neurological disorders. Recent research work has demonstrated that PPX exerts neuroprotection through mitochondria. However, the neuromodulator-related effects of PPX against traumatic brain injury (TBI) remain unexplored. The present study, therefore, investigated the mechanism of neuroprotection by PPX against oxidative stress, mitochondrial dysfunction and neuronal damage following TBI in rats. We hypothesized that the neuroprotection by PPX in TBI-subjected rats might involve activation of the Nrf2/HO-1 (also known as Nfe2l2/Hmox1) signaling pathway. PPX was injected intraperitoneally (0.25 mg/kg body weight and 1.0 mg/kg body weight) at different time intervals post-TBI. Several neurobehavioral parameters were assessed at 48 h post-TBI, and the brain was isolated for molecular and biochemical analysis. The results demonstrated that PPX treatment significantly improved the behavioral deficits, decreased the lipid peroxidation rate, increased glutathione levels and decreased 4-hydroxynonenal levels in TBI-subjected rats. PPX also increased the activities of glutathione peroxidase and superoxide dismutase enzymes. In addition, PPX treatment inhibited mitochondrial reactive oxygen species production, restored mitochondrial membrane potential and increased ATP levels after a TBI. Further, PPX treatment reduced the Bax/Bcl2 ratio and translocation of Bax to mitochondria and cytochrome-c to the cytosol. Finally, PPX treatment greatly accelerated the translocation of Nrf2 to the nucleus and upregulated HO-1 protein expression. We conclude that the neuroprotective effects of PPX are mediated by activation of the Nrf2/HO-1 signaling pathway following TBI.This article has an associated First Person interview with the first author of the paper.

Nrf2 activation ameliorates mechanical allodynia in paclitaxel-induced neuropathic pain

Paclitaxel-induced neuropathic pain (PINP) is refractory to currently used analgesics. Previous studies show a pivotal role of oxidative stress in PINP. Because the nuclear factor erythroid-2-related factor 2 (Nrf2) has been considered as the critical regulator of endogenous antioxidant defense, we here explored whether activation of Nrf2 could attenuate PINP. A rat model of PINP was established by intraperitoneal injection of paclitaxel (2 mg/kg) every other day with a final cumulative dose of 8 mg/kg. Hind paw withdrawal thresholds (PWTs) in response to von Frey filament stimuli were used to assess mechanical allodynia. We showed that a single dose of Nrf2 activator, oltipraz (10, 50, and 100 mg/kg), dose-dependently attenuated established mechanical allodynia, whereas repeated injection of oltipraz (100 mg· kg-1· d-1, i.p. from d 14 to d 18) almost abolished the mechanical allodynia in PINP rats. The antinociceptive effect of oltipraz was blocked by pre-injection of Nrf2 inhibitor trigonelline (20 mg/kg, i.p.). Early treatment with oltipraz (100 mg· kg-1· d-1, i.p. from d 0 to d 6) failed to prevent the development of the PINP, but delayed its onset. Western blot and immunofluorescence analysis revealed that the expression levels of Nrf2 and HO-1 were significantly upregulated in the spinal cord of PINP rats. Repeated injection of oltipraz caused further elevation of the expression levels of Nrf2 and HO-1 in the spinal cord of PINP rats, which was reversed by pre-injection of trigonelline. These results demonstrate that oltipraz ameliorates PINP via activating Nrf2/HO-1-signaling pathway in the spinal cord.

β-Asarone Exerts Antioxidative Effects on H2O2-Stimulated PC12 Cells by Activating Nrf2/HO-1 Pathway

Oxidative stress-mediated neuron damage is considered an important contributor to the pathogenesis and development of neurodegenerative diseases. Although β-asarone is widely known for its neuroprotective pharmacological properties, the exact mechanism of β-asarone against oxidative stress has not been fully elucidated. The aim of the present study was to investigate underlying mechanisms of β-asarone against oxidative damage in PC12 cells. Our results demonstrated that the treatment of β-asarone significantly alleviated the reduction in cell viability and the excessive accumulation of lactate dehydrogenase (LDH), malondialdehyde (MDA) and reactive oxygen species (ROS) by increasing the activity of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH). Moreover, β-asarone pretreatment also activated nuclear factor 2 erythroid-related factor 2 (Nrf2) and its downstream target heme oxygenase-1 (HO-1), which was involved in quenching reactive oxygen to inhibit oxidative stress. Furthermore, when silenced by Nrf2 siRNA, the protective effect of β-asarone was reduced and the oxidative stress induced by H2O2 was enhanced. In conclusion, our findings revealed that β-asarone could reduce oxidative stress via activating Nrf2/HO-1 pathway in PC12 cells, highlighting the potential therapeutic role of β-asarone in neurodegenerative diseases.

Effects of rhEPO on Nrf2 and HO-1 expression in rats with acute kidney injury and its protective effects on kidney

If the kidney suddenly loses its ability to remove waste, acute kidney injury (AKI) will occur that dangerous levels of waste may accumulate, and the chemical composition of the blood may become unbalanced. AKI usually develops rapidly within a few days and is very common in hospitalized patients, especially those in urgent need of intensive care. AKI can be fatal and requires serious treatment. However, it can be reversible. The purpose of this research was to investigate the effects of recombinant human erythropoietin (rhEPO) on the expression of nuclear factor E2-related factor 2 (Nuclear factor E2, Nrf2) and Heme oxygenase (HO-1) in rats AKI and its protective effects on the kidney. For this purpose, 40 SD rats were averagely and randomly divided into 4 groups: control group, sham operation group, model group, and rhEPO group. The rhEPO group was injected with 5% glucose mixed with rhEPO to form 3000 IU/ (kg/d) rhEPO. Except for the rhEPO group, three groups were injected with 5% glucose at the same dose level as the rhEPO group respectively. Before the third administration, the renal pedicle was clamped for 60 min and then perfused for 24 hours. Changes of Serum creatinine (Scr) and Urea nitrogen (BUN) of rats in each group were detected before and after modeling. Twenty-four hours after modeling, renal tissues of rats in each group were taken, and expressions of Nrf2 and HO-1 in renal tissues were detected by qRT-PCR and Western blot methods. There were no significant differences in Scr and BUN contents in the four groups before modeling (p&gt; 0.05). There were no significant differences in Scr and BUN contents in the control group and sham operation group after modeling compared with those before modeling (p&gt; 0.05). Expressions of Nrf2 and HO-1 in the rhEPO group were higher than those in the model group, the sham operation group and the control group (p&lt; 0.05), while expressions of Nrf2 and HO-1 in model group were higher than those in sham operation group and control group (p&lt; 0.05). There were no significant differences in expressions of Nrf2 and HO-1 between the sham operation group and the control group (p&gt; 0.05). rhEPO can induce expressions of Nrf2 and HO-1 in AKI rats. RhEPO has a protective effect on the kidney, which may be related to expressions of Nrf2 and HO-1.

Shenmai Injection Upregulates Heme Oxygenase-1 to Confer Protection Against Severe Acute Pancreatitis

BACKGROUND

To explore the mechanism of Shenmai injection (SMI) on severe acute pancreatitis (SAP) through heme oxygenase-1 (HO-1) signaling.

METHODS

A total of 40 male Sprague-Dawley (SD) rats (220-260 g) were grouped into the following four categories (n = 10): SAP + SMI + Zinc protoporphyrin (ZnPP), SAP + SMI, SAP, and sham surgery groups. ZnPP is a specific inhibitor of HO-1. Four percent of sodium taurocholate (1 mL/kg) was retrogradely injected via the pancreatic duct to induce the SAP model. The SAP group rats received 1.6 mL/kg saline by intravenous injection 30 min after the induction of SAP. The SAP + SMI group rats received 1.6 mL/kg SMI by intravenous injection 30 min after the induction of SAP. The SAP + SMI + ZnPP group rats received an intravenous injection of 1.6 mL/kg SMI and intraperitoneal administration of 30 mg/kg ZnPP 30 min after the SAP induction. Twenty-four hours after the SAP induction, blood samples were collected for the measurement of amylase, lipase, creatinine, myeloperoxidase, interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and HO-1 level, while tissue specimens were harvested for the determination of HO-1, TNF-α, and IL-10 mRNA level. Meanwhile, histopathological changes in organs (pancreas, lung, and kidney) were stored.

RESULTS

The serum concentration of amylase, lipase, creatinine, and myeloperoxidase was higher in the SAP group than in the SAP + SMI group. Treatment with SMI increased HO-1 and IL-10 level and reduced TNF-α level in serum and tissues compared to the SAP group (P < 0.05). Treatment with SMI abolished the organ-damaging effects of SAP (P < 0.05). Furthermore, suppression of HO-1 expression by ZnPP canceled the aforementioned effects.

CONCLUSIONS

SMI confers protection against the SAP-induced systemic inflammatory response and multiple organs damage via HO-1 upregulation.