Effect of Bromfenac on Reducing Neuroinflammation in an Ischemia-Reperfusion Glaucoma Model.

In the context of glaucoma, intraocular pressure (IOP) and age are recognized as the primary factors contributing to its onset and progression. However, significant reductions in IOP fail to completely halt its advancement. An emerging body of literature highlights the role of neuroinflammation in glaucoma. This study aimed to explore Bromfenac's anti-inflammatory properties in mitigating neuroinflammation associated with glaucoma using an ischemia-reperfusion (IR) glaucoma model. Bromfenac's impact on microglia and astrocytes under pressure was assessed via Western blotting and an enzyme-linked immunosorbent assay. Immunohistochemical staining was used to evaluate glial activation and changes in inflammatory marker expression in the IR model. Bromfenac led to the downregulation of inflammatory markers, which were elevated in the conditions of elevated pressure, and necroptosis markers were downregulated in astrocytes. In the IR model, elevated levels of GFAP and Iba-1 indicated glial activation. Following Bromfenac administration, levels of iNOS, COX-2, and PGE2-R were reduced, suggesting a decrease in neuroinflammation. Furthermore, Bromfenac administration in the IR model resulted in the improved survival of retinal ganglion cells (RGCs) and preservation of retinal function, as demonstrated by immunohistochemical staining and electroretinography. In summary, Bromfenac proved effective in diminishing neuroinflammation and resulted in enhanced RGC survival.

Crosstalk among Oxidative Stress, Autophagy, and Apoptosis in the Protective Effects of Ginsenoside Rb1 on Brain Microvascular Endothelial Cells: A Mixed Computational and Experimental Study.

OBJECTIVE: Brain microvascular endothelial cells (BMECs) were found to shift from their usually inactive state to an active state in ischemic stroke (IS) and cause neuronal damage. Ginsenoside Rb1 (GRb1), a component derived from medicinal plants, is known for its pharmacological benefits in IS, but its protective effects on BMECs have yet to be explored. This study aimed to investigate the potential protective effects of GRb1 on BMECs. METHODS: An in vitro oxygen-glucose deprivation/reperfusion (OGD/R) model was established to mimic ischemia-reperfusion (I/R) injury. Bulk RNA-sequencing data were analyzed by using the Human Autophagy Database and various bioinformatic tools, including gene set enrichment analysis (GSEA), Gene Ontology (GO) classification and enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, protein-protein interaction network analysis, and molecular docking. Experimental validation was also performed to ensure the reliability of our findings. RESULTS: Rb1 had a protective effect on BMECs subjected to OGD/R injury. Specifically, GRb1 was found to modulate the interplay between oxidative stress, apoptosis, and autophagy in BMECs. Key targets such as sequestosome 1 (SQSTM1/p62), autophagy related 5 (ATG5), and hypoxia-inducible factor 1-alpha (HIF-1α) were identified, highlighting their potential roles in mediating the protective effects of GRb1 against IS-induced damage. CONCLUSION: GRbl protects BMECs against OGD/R injury by influencing oxidative stress, apoptosis, and autophagy. The identification of SQSTM1/p62, ATG5, and HIF-1α as promising targets further supports the potential of GRb1 as a therapeutic agent for IS, providing a foundation for future research into its mechanisms and applications in IS treatment.

Short-Term Preconditioning with Insulin and Glucose Efficiently Protected the Kidney Against Ischemia-Reperfusion Injury via the P-AKT-Bax-Caspase-3 Signaling Pathway in Mice.

Objective: Insulin attaches insulin receptor to activate the PI3-kinase/Akt signaling to maintain glucose homeostasis and inhibit apoptosis. This study determined whether preconditioning with insulin and glucose protects the kidney against ischemia-reperfusion injury (IRI). Methods: Kidney IRI was performed in C57BL/6 mice by clamping the renal vessels for 30 min, followed by reperfusion for 24 h. A total subcutaneous 0.1 unit of insulin along with 10% glucose in drinking water was treated on the mice for 24 h before kidney IRI. The kidney function and injuries were investigated through the determination of BUN and Cr in blood plasma, as well as the apoptosis and the expression of P-AKT, BAX, and caspase-3 in the kidneys. The role of P-AKT in insulin-treated IRI kidneys was tested using an AKT inhibitor. The effects of the preconditional duration of insulin and glucose on IRI kidneys were investigated by expanding the treatment duration to 1, 3, and 6 days. Results: Preconditioning with insulin and glucose protected the kidney against IRI as manifested by a decrease in creatinine and BUN and a reduction of kidney tubular injury. The protection effect was mediated by P-AKT-BAX-caspase-3 signaling pathway resulting in suppression of apoptotic cell death. An AKT inhibitor partially reversed the protective effects of preconditional insulin. The preconditional duration for 1, 3, and 6 days had no differences in improving kidney functions and pathology. Conclusion: A short-term preconditioning with insulin and glucose protected the kidney from IRI through the activation of p-AKT and subsequent reduction of BAX-caspase-3-induced apoptosis. The short-term precondition provides a practicable strategy for protecting the kidney against predictable IRI, such as kidney transplant and major surgical operations with high risk of hypotension.

Dexmedetomidine's Effects on the Livers and Kidneys of Rats with Pancreatic Ischemia-Reperfusion Injury.

Objective: Pancreatic surgeries inherently cause ischemia-reperfusion (IR) injury, affecting not only the pancreas but also distant organs. This study was conducted to explore the potential use of dexmedetomidine, a sedative with antiapoptotic, anti-inflammatory, and antioxidant properties, in mitigating the impacts of pancreatic IR on kidney and liver tissues. Methods: A total of 24 rats were randomly divided into four groups: control (C), dexmedetomidine (D), ischemia reperfusion (IR), and dexmedetomidine ischemia reperfusion (D-IR). Pancreatic ischemia was induced in the IR and D-IR groups. Dexmedetomidine was administered intraperitoneally to the D and D-IR groups. Liver and kidney tissue samples were subjected to microscopic examinations after hematoxylin and eosin staining. The levels of thiobarbituric acid reactive substances (TBARS), aryllesterase (AES), catalase (CAT), and glutathione S-transferase (GST) enzyme activity were assessed in liver and kidney tissues. The serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine were measured. Results: A comparison of the groups revealed that the IR group exhibited significantly elevated TBARS (p < 0.0001), AES (p = 0.004), and CAT enzyme activity (p < 0.0001) levels in the liver and kidney compared to groups C and D. Group D-IR demonstrated notably reduced histopathological damage (p < 0.05) and low TBARS (p < 0.0001), AES (p = 0.004), and CAT enzyme activity (p < 0.0001) in the liver and kidney as well as low AST and ALT activity levels (p < 0.0001) in the serum compared to the IR group. Conclusion: The preemptive administration of dexmedetomidine before pancreatic IR provides significant protection to kidney and liver tissues, as evidenced by the histopathological and biochemical parameters in this study. The findings underscored the potential therapeutic role of dexmedetomidine in mitigating the multiorgan damage associated with pancreatic surgeries.

Anti-oxidative and anti-inflammatory effects of Ginkgo biloba extract (EGb761) on hindlimb skeletal muscle ischemia-reperfusion injury in rats.

In posterior spine surgery, retractors exert pressure on paraspinal muscles, elevating intramuscular pressure and compromising blood flow, potentially causing muscle injury during ischemia-reperfusion. Ginkgo biloba extract (EGb 761), known for its antioxidant and free radical scavenging properties and its role in treating cerebrovascular diseases, is investigated for its protective effects against muscle ischemia-reperfusion injury in vitro and in vivo. Animals were randomly divided into the control group, receiving normal saline, and experimental groups, receiving varying doses of EGb761 (25/50/100/200 mg/kg). A 2-h hind limb tourniquet-induced ischemia was followed by reperfusion. Blood samples collected pre-ischemia and 24 h post-reperfusion, along with muscle tissue samples after 24 h, demonstrated that EGb761 at 1000 µg/mL effectively inhibited IL-6 and TNF-α secretion in RAW 264.7 cells without cytotoxicity. EGb761 significantly reduced nitric oxide (NO) and malondialdehyde (MDA) levels, myeloperoxidase (MPO) activity, and increased glutathione (GSH) levels compared to the control after 24 h. Muscle tissue sections revealed more severe damage in the control group, indicating EGb761's potential in mitigating inflammatory responses and oxidative stress during ischemia-reperfusion injury, effectively protecting against muscle damage.

Gallic acid pretreatment mitigates parathyroid ischemia-reperfusion injury through signaling pathway modulation.

Thyroid surgery often results in ischemia-reperfusion injury (IRI) to the parathyroid glands, yet the mechanisms underlying this and how to ameliorate IRI remain incompletely explored. Our study identifies a polyphenolic herbal extract-gallic acid (GA)-with antioxidative properties against IRI. Through flow cytometry and CCK8 assays, we investigate the protective effects of GA pretreatment on a parathyroid IRI model and decode its potential mechanisms via RNA-seq and bioinformatics analysis. Results reveal increased apoptosis, pronounced G1 phase arrest, and significantly reduced cell proliferation in the hypoxia/reoxygenation group compared to the hypoxia group, which GA pretreatment mitigates. RNA-seq and bioinformatics analysis indicate GA's modulation of various signaling pathways, including IL-17, AMPK, MAPK, transient receptor potential channels, cAMP, and Rap1. In summary, GA pretreatment demonstrates potential in protecting parathyroid cells from IRI by influencing various genes and signaling pathways. These findings offer a promising therapeutic strategy for hypoparathyroidism treatment.

Icariin improves oxidative stress injury during ischemic stroke via inhibiting mPTP opening.

BACKGROUND: Ischemic stroke presents a significant threat to human health due to its high disability rate and mortality. Currently, the clinical treatment drug, rt-PA, has a narrow therapeutic window and carries a high risk of bleeding. There is an urgent need to find new effective therapeutic drugs for ischemic stroke. Icariin (ICA), a key ingredient in the traditional Chinese medicine Epimedium, undergoes metabolism in vivo to produce Icaritin (ICT). While ICA has been reported to inhibit neuronal apoptosis after cerebral ischemia-reperfusion (I/R), yet its underlying mechanism remains unclear. METHODS: PC-12 cells were treated with 200 µM H2O2 for 8 h to establish a vitro model of oxidative damage. After administration of ICT, cell viability was detected by Thiazolyl blue tetrazolium Bromide (MTT) assay, reactive oxygen species (ROS) and apoptosis level, mPTP status and mitochondrial membrane potential (MMP) were detected by flow cytometry and immunofluorescence. Apoptosis and mitochondrial permeability transition pore (mPTP) related proteins were assessed by Western blotting. Middle cerebral artery occlusion (MCAO) model was used to establish I/R injury in vivo. After the treatment of ICA, the neurological function was scored by ZeaLonga socres; the infarct volume was observed by 2,3,5-Triphenyltetrazolium chloride (TTC) staining; HE and Nissl staining were used to detect the pathological state of the ischemic cortex; the expression changes of mPTP and apoptosis related proteins were detected by Western blotting. RESULTS: In vitro: ICT effectively improved H2O2-induced oxidative injury through decreasing the ROS level, inhibiting mPTP opening and apoptosis. In addition, the protective effects of ICT were not enhanced when it was co-treated with mPTP inhibitor Cyclosporin A (CsA), but reversed when combined with mPTP activator Lonidamine (LND). In vivo: Rats after MCAO shown cortical infarct volume of 32-40%, severe neurological impairment, while mPTP opening and apoptosis were obviously increased. Those damage caused was improved by the administration of ICA and CsA. CONCLUSIONS: ICA improves cerebral ischemia-reperfusion injury by inhibiting mPTP opening, making it a potential candidate drug for the treatment of ischemic stroke.

TLR4 inhibitors through inhibiting (MYD88-TRIF) pathway, protect against experimentally-induced intestinal (I/R) injury.

Intestinal ischemia/reperfusion (I/R) injury is a serious condition that causes intestinal dysfunction and can be fatal. Previous research has shown that toll-like receptor 4 (TLR4) inhibitors have a protective effect against this injury. This study aimed to investigate the protective effects of TLR4 inhibitors, specifically cyclobenzaprine, ketotifen, amitriptyline, and naltrexone, in rats with intestinal (I/R) injury. Albino rats were divided into seven groups: vehicle control, sham-operated, I/R injury, I/R-cyclobenzaprine (10 mg/kg body weight), I/R-ketotifen (1 mg/kg body weight), I/R-amitriptyline (10 mg/kg body weight), and I/R-naltrexone (4 mg/kg body weight) groups. Anesthetized rats (urethane 1.8 g/kg) underwent 30 min of intestinal ischemia by occluding the superior mesenteric artery (SMA), followed by 2 h of reperfusion. Intestinal tissue samples were collected to measure various parameters, including malondialdehyde (MDA), nitric oxide synthase (NO), myeloperoxidase (MPO), superoxide dismutase (SOD), TLR4, intercellular adhesion molecule-1 (ICAM-1), nuclear factor kappa bp65 (NF-ĸBP65), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α), macrophages CD68, myeloid differentiation factor 88 (MYD88), and toll interleukin receptor-domain-containing adaptor-inducing interferon ß (TRIF). The use of TLR4 inhibitors significantly reduced MDA, MPO, and NO levels, while increasing SOD activity. Furthermore, it significantly decreased TLR4, ICAM-1, TNF-α, MCP-1, MYD88, and TRIF levels. These drugs also showed partial restoration of normal cellular structure with reduced inflammation. Additionally, there was a decrease in NF-ĸBP65 and macrophages CD68 staining compared to rats in the I/R groups. This study focuses on how TLR4 inhibitors enhance intestinal function and protect against intestinal (I/R) injury by influencing macrophages CD86 through (MYD88-TRIF) pathway, as well as their effects on oxidation and inflammation.

Crosstalk between ferroptosis and necroptosis in cerebral ischemia/reperfusion injury and Naotaifang formula exerts neuroprotective effect via HSP90-GCN2-ATF4 pathway.

BACKGROUND: Cerebral ischemia/reperfusion injury (CIRI) is a sequence of pathophysiological processes after blood recanalization in the patients with ischemic stroke, and has become the hinder for the rehabilitation. Naotaifang formula (NTF) has exhibited the clinical effectiveness for this disease. However, its action effects and molecular mechanisms against CIRI are not fully elucidated. PURPOSE: The research was to clarify the crosstalk between ferroptosis and necroptosis in CIRI, and uncover the mechanism underlying the neuroprotection of NTF. METHODS: This study established MCAO/R rat models with various reperfusion times. Western blot, transmission electron microscope, laser speckle imaging, immunofluorescence, immunohistochemistry and pathological staining were conducted to detect and analyze the obtained results. Subsequently, various NTF doses were used to intervene in MCAO/R rats, and biology experiments, such as western blot, Evans blue, immunofluorescence and immunohistochemistry, were used to analyze the efficacy of NTF doses. The effect of NTF was further clarified through in vitro experiments. Eventually, HT22 cells that suffered OGD/R were subjected to pre-treatment with plasmids overexpressing HSP90, MLKL, and GPX4 to indicate the interaction among ferroptosis and necroptosis. RESULTS: There was a gradual increase in the Zea Longa score and cerebral infarction volume following CIRI with prolonged reperfusion. Furthermore, the expression of factors associated with pro-ferroptosis and pro-necroptosis was upregulated in the cortex and hippocampus. NTF alleviated ferroptosis and necroptosis in a dose-dependent manner, downregulated HSP90 levels, reduced blood-brain barrier permeability, and thus protected nerve cells from CIRI. The results in vitro research aligned with those of the in vivo research. HSP90 and MLKL overexpression promoted necroptosis and ferroptosis while activating the GCN2-ATF4 pathway. GPX4 overexpression had no effect on necroptosis or the associated signaling pathway. The administration of NTF alone, as well as its combination with the overexpression of HSP90, MLKL, or GPX4 plasmids, decreased the expression levels of factors associated with pro-ferroptosis and pro-necroptosis and reduced the protein levels of the HSP90-GCN2-ATF4 pathway. Moreover, the regulatory effects of the NTF alone group on GSH, ferrous iron, and GCN2 were more significant compared with those of the HSP90 overexpression combination group. CONCLUSION: Ferroptosis and necroptosis were gradually aggravated following CIRI with prolonged reperfusion. MLKL overexpression may promote ferroptosis and necroptosis, while GPX4 overexpression may have little effect on necroptosis. HSP90 overexpression accelerated both forms of cell death via the HSP90-GCN2-ATF4 pathway. NTF alleviated ferroptosis and necroptosis to attenuate CIRI by regulating the HSP90-GCN2-ATF4 pathway. Our research provided evidence for the potential of drug development by targeting HSP90, MLKL, and GPX4 to protect against ischemic stroke.

Etomidate alleviates ovarian ischemia-reperfusion injury in rats.

BACKGROUND: This study investigates the protective effects of etomidate against oxidative damage in an experimental model of ovarian ischemia-reperfusion injury. METHODS: A total of 24 female rats were randomized into three groups. Group 1 served as the control. Group 2 underwent an ovarian torsion/detorsion procedure. Group 3 underwent similar procedures as Group 2; additionally, 4 mg/kg of etomidate was administered intraperitoneally 30 minutes before ovarian detorsion. Blood samples were analyzed for lipid peroxidation, pro-inflammatory cytokine levels, and antioxidant enzyme activity RESULTS: Biochemical analysis of blood samples revealed reductions in pro-inflammatory cytokines, including interleukin-1 Beta (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), in Group 3 compared to Group 2 (p=0.005, p=0.016, and p<0.001, respectively). Additionally, a decrease in malondialdehyde (MDA) levels was observed in Group 3 compared to Group 2 (p<0.001). In contrast, activities of antioxidant enzymes, including superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), were significantly increased in Group 3 compared to Group 2 (p=0.031 and p=0.001, respectively). Furthermore, Group 3 demonstrated notable reductions in histopathological scores for follicular degeneration, vascular occlusion, bleeding, and inflammation compared to Group 2 (p<0.001, p<0.001, p<0.001, and p=0.001, respectively). CONCLUSION: Etomidate alleviates ischemia-reperfusion injury in a rat ovarian torsion-detorsion model by improving both histopathological and biochemical outcomes.

The role of geraniol on hepatic ischemia-reperfusion injury model in rats.

BACKGROUND: Hepatic ischemia/reperfusion (I/R) injury is a significant clinical condition that can arise during liver resections, trauma, and shock. Geraniol, an isoterpene molecule commonly found in nature, possesses antioxidant and hepatoprotective properties. This study investigates the impact of geraniol on hepatic damage by inducing experimental liver I/R injury in rats. METHODS: Twenty-eight male Wistar Albino rats weighing 350-400 g were utilized for this study. The rats were divided into four groups: control group, I/R group, 50 mg/kg geraniol+I/R group, and 100 mg/kg geraniol+I/R group. Ischemia times were set at 15 minutes with reperfusion times at 20 minutes. Ischemia commenced 15 minutes after geraniol administration. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactic acid were measured, along with superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity levels in liver tissues. Liver tissues were also examined histopathologically. RESULTS: It was observed that intraperitoneal administration of 50 mg/kg and 100 mg/kg geraniol significantly reduced AST, lactic acid, and tumor necrosis factor-alpha (TNF-α) levels. The serum ALT level decreased significantly in the 50 mg/kg group, whereas no significant decrease was found in the 100 mg/kg group. SOD and GPx enzyme activities were shown to increase significantly in the 100 mg/kg group. Although there was an increase in these enzyme levels in the 50 mg/kg group, it was not statistically significant. Similarly, CAT enzyme activity increased in both the 50 mg/kg and 100 mg/kg groups, but the increase was not significant. The Suzuki score significantly decreased in both the 50 mg/kg and 100 mg/kg groups. CONCLUSION: The study demonstrates that geraniol reduced hepatic damage both biochemically and histopathologically and increased antioxidant defense enzymes. These findings suggest that geraniol could be used to prevent hepatic I/R injury, provided it is corroborated by large-scale and comprehensive studies.

Notoginseng leaf triterpenes promotes angiogenesis by activating the Nrf2 pathway and AMPK/SIRT1-mediated PGC-1/ERα axis in ischemic stroke.

Notoginseng leaf triterpenes (PNGL), derived from the dried stems and leaves of P. notoginseng, is a phytoestrogen that exerts many neuroprotective effects in vivo and in vitro of ischemic stroke. However, its impact on neurological restoration specifically in relation to angiogenesis following ischemic stroke remains unexplored. The aim of this study was to assess the effects of PNGL on angiogenesis subsequent to ischemic stroke. Male Sprague-Dawley rats were utilized in this study and were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). Post-ischemia, PNGL were administered through intraperitoneal (i.p.) injection. The high-performance liquid chromatography (HPLC) fingerprinting, triphenyltetrazolium chloride (TTC) staining, immunofluorescent staining, network pharmacology and western blot analyses were assessed to determine the therapeutical effect and molecular mechanisms of PNGL on cerebral ischemia/reperfusion injury. Our findings demonstrate that PNGL effectively reduced infarct volume, enhanced cerebral blood flow, and induced angiogenesis in rats subjected to MCAO/R. Notably, PNGL also facilitated neuronal proliferation and migration in HUMECs in vitro. The proangiogenic effects of PNGL were found to be linked to the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and the AMPK/SIRT1-mediated PGC-1/ERα axis, as well as the activation of neurological function. Our study provides evidence that PNGL hold promise as an active ingredient of inducing proangiogenic effects, potentially through the activation of the Nrf2 pathway and the AMPK/SIRT1-mediated PGC-1/ERα axis. These findings contribute to the understanding of novel mechanisms involved in the restoration of neurological function following PNGL treatment for ischemic stroke.

Investigating the Pharmacological Mechanisms of Total Flavonoids from Eucommia ulmoides Oliver Leaves for Ischemic Stroke Protection.

The aim of this study was to explore how the total flavonoids from Eucommia ulmoides leaves (EULs) regulate ischemia-induced nerve damage, as well as the protective effects mediated by oxidative stress. The cell survival rate was significantly improved compared to the ischemic group (p < 0.05) after treatment with the total flavonoids of EULs. The levels of reactive oxygen species (ROS), lactate dehydrogenase (LDH), and malondialdehyde (MDA) decreased, while catalase (CAT) and glutathione (GSH) increased, indicating that the total flavonoids of EULs can significantly alleviate neurological damage caused by ischemic stroke by inhibiting oxidative stress (p < 0.01). The mRNA expression level of VEGF increased (p < 0.01), which was consistent with the protein expression results. Meanwhile, the protein expression of ERK and CCND1 increased (p < 0.01), suggesting that the total flavonoids of EULs could protect PC12 cells from ischemic injury via VEGF-related pathways. MCAO rat models indicated that the total flavonoids of EULs could reduce brain ischemia-reperfusion injury. In conclusion, this study demonstrates the potential mechanisms of the total flavonoids of EULs in treating ischemic stroke and their potential therapeutic effects in reducing ischemic injury, which provides useful information for ischemic stroke drug discovery.

High-dose sinomenine attenuates ischemia/reperfusion-induced hepatic inflammation and oxidative stress in rats with diabetes mellitus.

INTRODUCTION: Ischemia-reperfusion (I/R) injury, resulting from blood flow interruption and its subsequent restoration, is a prevalent complication in liver surgery. The liver, as a crucial organ for carbohydrate and lipid metabolism, exhibits decreased tolerance to hepatic I/R in patients with diabetes mellitus (DM), resulting in a significant increase in hepatic dysfunction following surgery. This may be attributed to elevated oxidative stress and inflammation. Our prior research established sinomenine's (SIN) protective role against hepatic I/R injury. Nevertheless, the impact of SIN on hepatic I/R injury in DM rats remains unexplored. OBJECTIVE AND METHODS: This study aimed to investigate the therapeutic potential of SIN in hepatic I/R injury in DM rats and elucidate its mechanism. Diabetic and hepatic I/R injury models were established in rats through high-fat/sugar diet, streptozotocin injection, and hepatic blood flow occlusion. Liver function, oxidative stress, inflammatory reaction, histopathology, and Nrf-2/HO-1 signaling pathway were evaluated by using UV spectrophotometry, biochemical assays, enzyme-linked immunosorbent assay, hematoxylin-eosin staining, and Western blot analysis. RESULTS: High-dose SIN (300 mg/kg) significantly attenuated hepatic I/R injury in DM rats, reducing serum activities of ALT and AST, decreasing the AST/ALT ratio, enhancing tissue contents of SOD and GSH-Px, suppressing the levels of TNF-α and IL-6, improving the liver histopathology, and activating Nrf-2/HO-1 signaling by promoting Nrf-2 trans-location from cytoplasm to nucleus. Low-dose SIN (100 mg/kg) was ineffective. CONCLUSIONS: This study demonstrates that high-dose sinomenine's mitigates hepatic I/R-induced inflammation and oxidative stress in diabetes mellitus (DM) rats via Nrf-2/HO-1 activation, suggesting its potential as a preventive strategy for hepatic I/R injury in DM patients.

Inhibition of the protective effects of preconditioning in ischemia-reperfusion injury by chronic methadone: the role of pAkt and pSTAT3.

Cardiac ischemic preconditioning (Pre) reduces cardiac ischemia-reperfusion injury (IRI) by stimulating opioid receptors. Chronic use of opioids can alter the signaling pathways. We investigated the effects of chronic methadone use on IRI and Pre. The experiments were performed on isolated hearts of male Wistar rats in four groups: IRI, Methadone + IRI (M-IRI), Pre + IRI (Pre-IRI), Methadone + Pre + IRI (M-Pre-IRI). The infarct size (IS) in the Pre-IRI group was smaller than the IRI group (26.8% vs. 47.8%, P < 0.05). In the M-IRI and M-Pre-IRI groups, the infarct size was similar to the IRI group. Akt (Ak strain transforming) phosphorylation in the Pre-IRI, M-IRI, and M-Pre-IRI groups was significantly higher than in the IRI group (0.56 ± 0.15, 0.63 ± 0.20, and 0.93 ± 0.18 vs 0.28 ± 0.17 respectively). STAT3 (signal transducer and activator of transcription 3) phosphorylation in the Pre-IRI and M-Pre-IRI groups (1.38 ± 0.14 and 1.46 ± 0.33) was significantly higher than the IRI and M-IRI groups (0.99 ± 0.1 and 0.98 ± 0.2). Thus, chronic use of methadone not only has no protective effect against IRI but also destroys the protective effects of ischemic preconditioning. This may be due to the hyperactivation of Akt and changes in signaling pathways.

Discovery of Novel Ortho-Aminophenol Derivatives Targeting Lipid Peroxidation with Potent Antiferroptotic Activities.

The concept of ferroptosis inhibition has gained growing recognition as a promising therapeutic strategy for addressing a wide range of diseases. Here, we present the discovery of four series of ortho-aminophenol derivatives as potential ferroptosis inhibitors beginning with the endogenous substance 3-hydroxyanthranilic acid (3-HA) by employing quantum chemistry techniques, in vitro and in vivo assays. Our findings reveal that these ortho-aminophenol derivatives exhibit unique intra-H bond interactions, compelling ortho-amines to achieve enhanced alignment with the aromatic π-system, thereby expanding their activity. Notably, compounds from all four series display remarkable activity against RSL3-induced ferroptosis, showcasing an activity 100 times more than that of 3-HA. Furthermore, these compounds also demonstrate robust in vivo efficacy in protecting mice from kidney ischemia-reperfusion injury and acetaminophen-induced hepatotoxicity. In summary, we provide four distinct series of active scaffolds that significantly expand the chemical space of ferroptosis inhibitors, serving as valuable insights for future structural modifications.

Nepetoidin B Alleviates Liver Ischemia/Reperfusion Injury via Regulating MKP5 and JNK/P38 Pathway.

Background: Nepetoidin B (NB) has been reported to possess anti-inflammatory, antibacterial, and antioxidant properties. However, its effects on liver ischemia/reperfusion (I/R) injury remain unclear. Methods: In this study, a mouse liver I/R injury model and a mouse AML12 cell hypoxia reoxygenation (H/R) injury model were used to investigate the potential role of NB. Serum transaminase levels, liver necrotic area, cell viability, oxidative stress, inflammatory response, and apoptosis were evaluated to assess the effects of NB on liver I/R and cell H/R injury. Quantitative polymerase chain reaction (qPCR) and Western blotting were used to measure mRNA and protein expression levels, respectively. Molecular docking was used to predict the binding capacity of NB and mitogen-activated protein kinase phosphatase 5 (MKP5). Results: The results showed that NB significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, liver necrosis, oxidative stress, reactive oxygen species (ROS) content, inflammatory cytokine content and expression, inflammatory cell infiltration, and apoptosis after liver I/R and AML12 cells H/R injury. Additionally, NB inhibited the JUN protein amino-terminal kinase (JNK)/P38 pathway. Molecular docking results showed good binding between NB and MKP5 proteins, and Western blotting results showed that NB increased the protein expression of MKP5. MKP5 knockout (KO) significantly diminished the protective effects of NB against liver injury and its inhibitory effects on the JNK/P38 pathway. Conclusion: NB exerts hepatoprotective effects against liver I/R injury by regulating the MKP5-mediated P38/JNK signaling pathway.

Forsythoside B alleviates cerebral ischemia-reperfusion injury via inhibiting NLRP3 inflammasome mediated by SIRT1 activation.

BACKGROUND: The inflammatory response is a key factor in the pathogenesis of cerebral ischemia/reperfusion injury (CIRI), and anti-inflammatory interventions may offer a promising therapeutic strategy. Forsythoside B (FB) is a phenylethanoid glycoside isolated from Forsythiae fructus, which has been reported to have anti-inflammatory effects. However, the mechanism of the neuroprotective effect of FB on CIRI remains unclear. METHODS: Adult male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion/reperfusion (MCAO/R). FB was administered intraperitoneally for 3 days prior to MCAO/R. Cerebral infarct volume and neurological deficit score were used as indices to evaluate MCAO/R injury. The serum levels of inflammatory factors and antioxidant enzymes were measured. The activation of silent information regulator 2 homolog 1 (Sirt1) and the inhibition of the nucleotide-binding oligomerization domain-like receptor with a pyrin domain 3 (NLRP3) pathway were assessed through western blot and immunohistochemistry analysis. Furthermore, the rats were treated with Sirt1 shRNA 3 days before MCAO/R by stereotactical injection into the ipsilateral hemispheric region to assess the impact of Sirt1 knockdown on the protection of FB during MCAO/R. RESULTS: FB reduced cerebral infarct volume and neurological deficit score in MCAO/R rats. FB reduced pathological changes and cell apoptosis in the hippocampal CA1 region and cortex on the ischemic side of rats. FB inhibited the serum levels of inflammatory factors and increased the activities of antioxidant enzymes. Further study showed that FB inhibited the activation of the NLRP3 pathway and induced Sirt1 activation. CONCLUSION: FB demonstrated neuroprotective and anti-inflammatory effects by inhibiting the NLRP3 pathway through Sirt1 activation in CIRI.

Benzoylaconine Protects Skeletal Muscle Against Ischemia-Reperfusion Injury Through Activation of IF1-Dependent AMPK/Nrf2 Axis.

Background: Aconitum carmichaelii (Fuzi) has been conventionally used to cure a variety of ailments, such as pain, cold sensations, and numbness of limb muscles (Bi Zheng) in China. Our prior investigations identified Benzoylaconine (BAC) as a bioactive alkaloid derived from Aconitum carmichaelii, with other studies also demonstrating its significant pharmacological potential. Purpose: This study aimed to explore the potential of BAC as a protective agent against skeletal muscle ischemia-reperfusion (I/R) injury and to elucidate the underlying mechanisms. Methods: In vivo models involved subjecting Sprague-Dawley rats to I/R through femoral artery ligation followed by reperfusion, while in vitro models utilized C2C12 cells subjected to hypoxia/reoxygenation (H/R). CCK-8 assay was used to assess cell viability. TUNEL staining and flow cytometric analysis were used to measure cell apoptosis. Biochemical assay was used to assess skeletal muscle injury and oxidative stress. Immunofluorescence and Western blot were performed to determine protein levels. Results: BAC effectively protected muscle tissue from I/R injury, enhancing cell viability (p<0.01), elevating SOD levels (p<0.05), and reducing CK (p<0.01), LDH (p<0.01), ROS (p<0.01), MDA (p<0.01), and apoptosis-related molecules in vivo and in vitro (p<0.05, p<0.01). Mechanistically, BAC increased the expression of IF1, phosphorylated AMPK, facilitated the translocation of nuclear Nrf2, and induced the expression of HO-1 (p<0.01). Notably, AMPK inhibitor Compound C significantly hindered the ability of BAC to ameliorate H/R-induced cell injury (p<0.05), oxidative stress(p<0.01), and apoptosis (p<0.05), as well as promote Nrf2 nuclear translocation (p<0.01). Moreover, silencing of IF1 with siRNA abolished BAC-induced activation of AMPK/Nrf2 axis (p<0.01). Conclusion: Our study provides novel evidence supporting the potential of BAC as a myocyte-protective agent against I/R injury, and we establish a previously unknown mechanism involving the activation of the IF1-dependent AMPK/Nrf2 axis in mediating the protective effects of BAC.

Enhanced effect of limb remote ischemic postconditioning combined with paeoniflorin on alleviating cerebral ischemic injury via neutrophil NADPH pathway.

BACKGROUND: Limb remote ischemic postconditioning (LRIP) and paeoniflorin (PF) both can ameliorate cerebral ischemia reperfusion (I/R) injury. At present, whether LRIP combined with PF can achieve better therapeutic effect is unknown. PURPOSE: This study explored the alleviating effect and mechanism of LRIP in combination with PF on cerebral I/R injury in rats. METHODS: Middle cerebral artery occlusion (MCAO) surgery was performed on rats except Sham group. Then PF (2.5 mg/kg, 5 mg/kg, 10 mg/kg) was administrated by intraperitoneal injection 10 min before the start of reperfusion. LRIP was operated on the left femoral artery at 0 h of reperfusion. Behavioral testing was used to assess neurological impairment, while TTC staining was used to examine infarct volume. Protein expression of MyD88, TRAF6, p38-MAPK and phosphorylation of p47phox in neutrophils from rat peripheral blood were tested by Western blot. Rat bone marrow neutrophils were extracted and incubated for 24 h with serum from rats after LRIP combined with PF. p38 MAPK inhibitor group was administrated SB203580 while the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor group was administrated Apocynin. Neutrophils were stimulated by fMLP (10 µM). Reactive oxygen species (ROS) production and protein expression of MyD88, TRAF6, p38 MAPK, and p47phox (ser 304 and ser 345) were detected. RESULTS: LRIP combined with PF (5 mg/kg) reduced cerebral infarct volume, ameliorated neurological deficit score (NDS), decreased fMLP-stimulated ROS release and downregulated the protein expression of MyD88, TRAF6, p38-MAPK and phosphorylation of p47phox (ser 304 and ser 345) in neutrophils. CONCLUSION: The protective effect of LRIP combined with PF on cerebral I/R injury was better than either alone. Taken together, we provided solid evidence to demonstrate that the combination of LRIP and PF had potential to alleviate cerebral I/R injury, which was regulated by MyD88-TRAF6-p38 MAPK pathway and neutrophil NADPH oxidase pathway.