Effects of Apocynin on Liver Ischemia-Reperfusion Injury in Rats

Modulatory effects of quercetin on histological changes, biochemical and oxidative stress of rat placenta induced by inhalation exposure to crude oil vapor

The inhalation exposure to crude oil vapor (COV) has been shown to have adverse effects on the placenta and fetal development. The modulatory effects of quercetin (QUE) as a natural phenolic compound with antioxidant properties are promising for the protection of placental structure. This study aimed to investigate the modulatory role of QUE in mitigating histopathological damage, oxidative stress, and biochemical alteration in the placenta of COV-exposed pregnant rats. Forty-eight pregnant rats were divided into eight groups (days 15 and 20) as follows: 1-2) Control groups, 3-4) COV groups, 5-6) COV+QUE groups, and 7-8) QUE-treated groups (50 mg/kg). The inhalation method was used to expose pregnant rats to COV, and QUE was administered orally. On the 15th and 20th days of gestation, placental tissue was analyzed using PAS and H&E staining and immunohistochemistry. The expression of the caspase-3 gene and oxidative stress biomarkers including TAC, CAT, MDA, GPx, and SOD were investigated in the placental tissue. The COV significantly decreased the weight, diameter, and thickness of the placenta as well as the thickness of the junctional zone and labyrinth and the number of trophoblast giant cells in 15- and 20-day-old placentas (P<0.05). Also, COV significantly increased placental expression of caspase-3 and the oxidative stress biomarkers (P<0.05). The administration of QUE along with exposure to COV reduced morphometric and histological alteration, oxidative stress, and caspase-3 expression (P<0.05). Our findings indicated that QUE in COV-exposed pregnant rats can prevent placental histopathological alternations by increasing the activity of the antioxidant system.

The Effects of Apocynin on Monosodium Glutamate Induced Liver Damage of Rats

Monosodium glutamate (MSG) is found in refined foods. Apocynin (APO) is a selective NADPH oxidase (NOX) inhibitor. The aim of this experimental study was to investigate possible effects of MSG and the curative effects of APO in rats. Twenty-eight male Sprague-Dawley rats were randomly divided into four groups (Normal control, APO, MSG and MSG + APO, n:7 for each group). The MSG and MSG + APO groups received 120 mg/kg MSG solution orally for 28 consecutive days. The APO and MSG + APO groups received 25 mg/kg APO solution orally for 5 days until the end of the experiment. At the end of the experiment, all rats were sacrificed and liver tissue and blood samples were taken for histological, ultrastructural, and biochemical analyses. In the MSG group, vacuolization and loss in glycogen content in the hepatocytes, leukocyte infiltration and fibrosis in the liver parenchyme and portal triads, were observed. Terminal deoxynucleotidyl transferase dUTP (TUNEL)-positivity and NADPH oxidase (NOX)-2-positivity were higher in the MSG group compared with the other experimental groups. The concentrations of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin, malondialdehyde (MDA), and myeloperoxidase (MPO) were higher, whereas albumin, glutathione (GSH), and superoxide (SOD) levels were lower in the MSG group. All these data has been reversed in MSG + APO group. The histological and biochemical criteria indicated the prominent ameliorating effect of APO on MSG -induced liver injury.

Does apocynin increase liver regeneration in the partial hepatectomy model?

BACKGROUND

Hepayocyte loss may develop secondary to liver surgery and at this point liver regeneration plays a significant act in terms of liver reserve. The purpose of this research was to investigate the efficacy of apocynin on liver regeneration and preservation after partial hepatectomy in rats.

METHODS

A total of 32 rats, have been divided into 4 groups (n: 8) for hepatectomy model. Inflammatory and antiinflammatory parameters were measured from blood and liver tissue samples. In addition, the effects of apocynin were examined immunohistochemically and histopathologically from liver tissue.

RESULTS

In liver tissue samples, a significant difference has been found in glutathione peroxidase, total nitrite, catalase, oxidative stress index, total antioxidant and total oxidant status between sham and hepatectomy groups. A significant difference has been achieved between hepatectomy and posthepatectomy-Apocynin in terms of glutathione peroxidase and oxidative stress index. Total antioxidant status, oxidative stress index, and total oxidant status were significantly different only between the sham and the hepatectomy groups. Statistical differences were found between sham and hepatectomy groups and between hepatectomy and pre+post-hepatectomy-Apocynin groups in terms of serum glutathione, malondialdehyde, total nitrite, and L-Arginine. There were significant differences between the sham and hepatectomy groups, between hepatectomy and posthepatectomy-apocynin groups, between posthepatctomy-apocynin and pre+posthepatectomy-apocynin groups in terms of sinusoidal dilatation, intracytoplasmic vacuolization and glycogen loss (p < 0.001), in all histopathologic parameters except sinusoidal dilatation (p < 0.05). However, significant Ki-67 increases have been elaborated in hepatectomy, posthepatectomy-apocynin, and pre+posthepatectomy-apocynin groups compared to sham group (p < 0.001), in pre+posthepatectomy apocynin group compared to hepatectomy and posthepatectomy-apocynin groups (p < 0.001).

DISCUSSION

Histopathology, immunohistochemistry, and biochemistry results of this study revealed that apocynin has a protective effect on enhancing liver regeneration in partial hepatectomy cases in rats.

A review on experimental surgical models and anesthetic protocols of heart failure in rats

Heart failure (HF) is a serious health and economic burden worldwide, and its prevalence is continuously increasing. Current medications effectively moderate the progression of symptoms, and there is a need for novel preventative and reparative treatments. The development of novel HF treatments requires the testing of potential therapeutic procedures in appropriate animal models of HF. During the past decades, murine models have been extensively used in fundamental and translational research studies to better understand the pathophysiological mechanisms of HF and develop more effective methods to prevent and control congestive HF. Proper surgical approaches and anesthetic protocols are the first steps in creating these models, and each successful approach requires a proper anesthetic protocol that maintains good recovery and high survival rates after surgery. However, each protocol may have shortcomings that limit the study's outcomes. In addition, the ethical regulations of animal welfare in certain countries prohibit the use of specific anesthetic agents, which are widely used to establish animal models. This review summarizes the most common and recent surgical models of HF and the anesthetic protocols used in rat models. We will highlight the surgical approach of each model, the use of anesthesia, and the limitations of the model in the study of the pathophysiology and therapeutic basis of common cardiovascular diseases.

NADPH Oxidase-Mediated Testicular Oxidative Imbalance Regulates the TXNIP/NLRP3 Inflammasome Axis Activation after Ischemia Reperfusion Injury

Oxidative stress, inflammation and germ cell death are the main characteristics of testicular ischemia reperfusion injury (tIRI), which is considered as the underlying mechanism for testicular torsion and detorsion. The study aimed to examine the effect of tIRI-activated NADPH oxidase (NOX) on the expression of the NLRP3 inflammasome pathway components. Three groups of male Sprague-Dawley rats (n = 12 each) were studied: sham, unilateral tIRI only and tIRI treated with apocynin, a NOX-specific inhibitor. The tIRI rat model was subjected to 1 h of ischemia followed by 4 h of reperfusion. H&E staining, real time PCR, biochemical assays, and Western blot were utilized to evaluate spermatogenic damage, gene expression, oxidative stress markers, and NLRP3 pathway components, respectively. As a result of tIRI, decreased total antioxidant capacity and suppressed activities of superoxide dismutase and catalase were associated with spermatogenic arrest. The components of the NLRP3 inflammasome pathway (TXNIP, NLRP3, ASC, caspase-1, GSDMD, MMP-9) were upregulated transcriptionally and post-transcriptionally during tIRI. In parallel, tissue inflammation was demonstrated by a marked increase in the concentrations of myeloperoxidase, IL-1β, and IL-18. Apocynin treatment prevented testicular oxidative stress and inflammation. Thus, NOX inhibition by apocynin prevented ROS accumulation, proinflammatory cytokine overexpression and NLRP3 inflammasome activation during tIRI.

Therapeutic effects of apocynin on ovarian ischemia-reperfusion induced lung injury

Ovarian ischemia-reperfusion (I-R) injury may damage remote organs, including the lungs. We investigated whether apocynin, a NADPH oxidase inhibitor, might protect against ovarian I-R induced apoptosis in the lungs of rats. Bilateral ovarian I-R was induced for 3 h, then apocynin was applied at two concentrations. Lung tissue was evaluated using spectrophotometric and immunohistochemical methods. We found that I-R increased total oxidant status (TOS), oxidative stress index (OSI) and myeloperoxidase (MPO) levels, and immunostaining of nuclear factor kappa-B (NF-κB), light chain 3B (LC3B), interleukin 1-beta (IL-1β), caspase-3 and tumor necrosis factor-alpha (TNF-α), but decreased superoxide dismutase (SOD) values. Apocynin application to I-R injured rats enhanced recovery of lung tissue oxidants and improved both histology and frequency of apoptosis.

Isoflurane upregulates microRNA-9-3p to protect rats from hepatic ischemia-reperfusion injury through inhibiting fibronectin type III domain containing 3B

Isoflurane has been studied in ischemia-reperfusion injury, while the regulatory mechanism by which isoflurane regulates microRNA(miR)-9-3p in hepatic ischemia/reperfusion injury (HIRI) via targeting fibronectin type III domain containing 3B (FNDC3B) remains seldom investigated. This study aims to determine the role of miR-9-3p in HIRI progression under the treatment of isoflurane. Rat HIRI models were established and treated with isoflurane. MiR-9-3p was altered to assess its role in inflammation, oxidative stress, transaminases, pathology, and hepatocyte apoptosis in HIRI rat liver tissues. Expression of miR-9-3p and FNDC3B in rat liver tissues was determined, and the targeting relationship between miR-9-3p and FNDC3B was confirmed using bioinformatic prediction and dual luciferase reporter gene assay. MiR-9-3p was downregulated, whereas FNDC3B was upregulated in HIRI rat liver tissues. Isoflurane treatment upregulated miR-9-3p and attenuated pathological changes, inflammation, oxidative stress, transaminases, and hepatocyte apoptosis in HIRI rat liver tissues. MiR-9-3p upregulation further strengthened the effect of isoflurane on HIRI, while miR-9-3p downregulation suppressed the therapeutic role of isoflurane. FNDC3B was confirmed as a target gene of miR-9-3p. Isoflurane upregulates miR-9-3p to protect rats from HIRI by inhibiting FNDC3VB. Our research may provide novel targets for HIRI treatment.

The Protective Effect of Traditional Chinese Medicine on Liver Ischemia-Reperfusion Injury

Liver ischemia-reperfusion (I/R) injury occurs during transplantation and major hepatic surgery, which may lead to postoperative liver dysfunction. More and more traditional Chinese medicines (TCMs) have been used to treat liver ischemia-reperfusion injury. The purpose of this review is to evaluate the different protective effects of TCMs in the treatment of liver ischemia-reperfusion injury and to summarize its possible mechanisms. The results indicate that TCMs attenuate liver I/R injury via multiple mechanisms, including antioxidation stress, anti-inflammatory response, antiapoptosis, and inhibiting endoplasmic reticulum stress. However, the in-depth mechanism of the protective effects of these traditional Chinese medicines still remains unknown.

Anti-apoptotic effect of silymarin-loaded chitosan nanoparticles on hippocampal caspase-3 and Bcl-2 expression following cerebral ischemia/reperfusion injury

BACKGROUND

Cerebral ischemia/reperfusion (I/R) causes memory and learning impairments and apoptosis in the hippocampus. The aim of present study aimed to investigate the anti-apoptotic effects of silymarin-loaded chitosan nanoparticles (SM-CS-NPs) on the expression of Bcl-2 and Caspase-3 genes in hippocampal neurons after I/R injury.

MATERIAL AND METHODS

SM and SM-CS-NPs were orally administered (15 mg/kg) for 14 days, and then cerebral I/R injury was induced by the bilateral common carotid artery occlusion (BCCAO). One day after I/R induction, memory and learning impairments and various biochemical estimations were assessed.

RESULTS

Our results indicated that SM-CS-NPs improved I/R-induced memory and learning impairments and oxidative damage in the hippocampal region. The qRT-PCR analysis indicated that SM-CS-NPs pretreatment inhibited I/R-induced neuronal apoptosis by increasing the expression of Bcl-2 and decreasing the expression of Caspase-3 in the hippocampus.

CONCLUSION

These findings suggest that SM-CS-NPs exert neuroprotective effects, and the neuroprotection is likely to be associated with the regulation of Bcl-2 and Caspase-3, leading to inhibition of apoptotic cell death in hippocampal neurons.

Review: Ischemia Reperfusion Injury-A Translational Perspective in Organ Transplantation

Thanks to the development of new, more potent and selective immunosuppressive drugs together with advances in surgical techniques, organ transplantation has emerged from an experimental surgery over fifty years ago to being the treatment of choice for many end-stage organ diseases, with over 139,000 organ transplants performed worldwide in 2019. Inherent to the transplantation procedure is the fact that the donor organ is subjected to blood flow cessation and ischemia during harvesting, which is followed by preservation and reperfusion of the organ once transplanted into the recipient. Consequently, ischemia/reperfusion induces a significant injury to the graft with activation of the immune response in the recipient and deleterious effect on the graft. The purpose of this review is to discuss and shed new light on the pathways involved in ischemia/reperfusion injury (IRI) that act at different stages during the donation process, surgery, and immediate post-transplant period. Here, we present strategies that combine various treatments targeted at different mechanistic pathways during several time points to prevent graft loss secondary to the inflammation caused by IRI.

Hepatic 31 P-magnetic resonance spectroscopy identified the impact of melatonin-pretreated mitochondria in acute liver ischaemia-reperfusion injury

Acute liver ischaemia-reperfusion injury (IRI), commonly encountered during liver resection and transplantation surgery, is strongly associated with unfavourable clinical outcome. However, a prompt and accurate diagnosis and the treatment of this entity remain formidable challenges. This study tested the hypothesis that ³¹ P-magnetic resonance spectroscopy (³¹ P-MRS) findings could provide reliable living images to accurately identify the degree of acute liver IRI and melatonin-pretreated mitochondria was an innovative treatment for protecting the liver from IRI in rat. Adult male SD rats were categorized into group 1 (sham-operated control), group 2 (IRI only) and group 3 (IRI + melatonin [ie mitochondrial donor rat received intraperitoneal administration of melatonin] pretreated mitochondria [10 mg/per rat by portal vein]). By the end of study period at 72 hours, ³¹ P-MRS showed that, as compared with group 1, the hepatic levels of ATP and NADH were significantly lower in group 2 than in groups 1 and 3, and significantly lower in group 3 than in group 1. The liver protein expressions of mitochondrial-electron-transport-chain complexes and mitochondrial integrity exhibited an identical pattern to ³¹ P-MRS finding. The protein expressions of oxidative stress, inflammatory, cellular stress signalling and mitochondrial-damaged biomarkers displayed an opposite finding of ³¹ P-MRS, whereas the protein expressions of antioxidants were significantly progressively increased from groups 1 to 3. Microscopic findings showed that the fibrotic area/liver injury score and inflammatory and DNA-damaged biomarkers exhibited an identical pattern of cellular stress signalling. Melatonin-pretreated mitochondria effectively protected liver against IRI and ³¹ P-MRS was a reliable tool for measuring the mitochondrial/ATP consumption in living animals.

Astaxanthin in Liver Health and Disease: A Potential Therapeutic Agent

Astaxanthin is a carotenoid derived from oxygen-containing non-vitamin A sources and is mainly obtained from marine organisms. Studies have demonstrated that astaxanthin is a natural antioxidant product and it is widely used in the fields of medicine, health-care products and cosmetics. Studies have shown that astaxanthin has important preventive and therapeutic effects on liver fibrosis, non-alcoholic fatty liver, liver cancer, drug and ischemia-induced liver injury, and its mechanism is related to antioxidant and anti-inflammatory activities, and the regulation of multiple signaling pathways. In this review, we discuss the latest data on astaxanthin in the prevention and treatment of liver diseases. An understanding of the structure, source and mechanism of action of astaxanthin in the body would not only provide a theoretical basis for its clinical application but could also have important significance in screening and improving related compounds for the treatment of liver diseases.

Current Knowledge about the Effect of Nutritional Status, Supplemented Nutrition Diet, and Gut Microbiota on Hepatic Ischemia-Reperfusion and Regeneration in Liver Surgery

Ischemia-reperfusion (I/R) injury is an unresolved problem in liver resection and transplantation. The preexisting nutritional status related to the gut microbial profile might contribute to primary non-function after surgery. Clinical studies evaluating artificial nutrition in liver resection are limited. The optimal nutritional regimen to support regeneration has not yet been exactly defined. However, overnutrition and specific diet factors are crucial for the nonalcoholic or nonalcoholic steatohepatitis liver diseases. Gut-derived microbial products and the activation of innate immunity system and inflammatory response, leading to exacerbation of I/R injury or impaired regeneration after resection. This review summarizes the role of starvation, supplemented nutrition diet, nutritional status, and alterations in microbiota on hepatic I/R and regeneration. We discuss the most updated effects of nutritional interventions, their ability to alter microbiota, some of the controversies, and the suitability of these interventions as potential therapeutic strategies in hepatic resection and transplantation, overall highlighting the relevance of considering the extended criteria liver grafts in the translational liver surgery.