Oxidative stress in sepsis. Possible production of free radicals through an erythrocyte-mediated positive feedback mechanism

Investigating the individual and combined effects of coenzyme Q10 and vitamin C on CLP-induced cardiac injury in rats

Sepsis-induced cardiac injury represents a major clinical challenge, amplifying the urgency for effective therapeutic interventions. This study aimed to delve into the individual and combined prophylactic effects of Vitamin C (Vit C) and Coenzyme Q10 (CoQ10) against inflammatory heart injury in a cecal ligation and puncture (CLP) induced polymicrobial sepsis rat model. Thirty adult female Sprague-Dawley rats were randomly divided into five groups: Control, CLP, Vitamin C, CoQ10, and Vit C + CoQ10, each consisting of six rats. Treatments were administered orally via gavage for 10 days prior to the operation. Eighteen hours post-sepsis induction, the animals were euthanized, and specimens were collected for analysis. The study examined variations in oxidative (TOS, OSI, MDA, MPO) and antioxidative markers (TAS, SOD, CAT, GSH), histopathological changes, inflammatory cytokine concentrations (TNF-α, IL-1β), nitric oxide (NO) dynamics, and cardiac indicators such as CK-MB. Impressively, the combined regimen markedly diminished oxidative stress, and antioxidative parameters reflected notable enhancements. Elevated NO levels, a central player in sepsis-driven inflammatory cascades, were effectively tempered by our intervention. Histological examinations corroborated the biochemical data, revealing diminished cardiac tissue damage in treated subjects. Furthermore, a marked suppression in pro-inflammatory cytokines was discerned, solidifying the therapeutic potential of our intervention. Interestingly, in certain evaluations, CoQ10 exhibited superior benefits over Vit C. Collectively, these findings underscore the potential therapeutic promise of Vit C and CoQ10 combination against septic cardiac injuries in rats.

Hematologic System Dysregulation in Critically Ill Septic Patients with Anemia-A Retrospective Cohort Study

Sepsis can affect various organs as well as the hematologic system. Systemic dysregulation, present in sepsis, affects particularly red blood cells (RBCs). One of the widely available RBC indices is RBC distribution width (RDW). Sepsis may also affect hemostasis, with septic patients presenting with coagulopathy or disseminated intravascular coagulation. The aim of our study was to analyze the impact of sepsis on RBC indices and coagulation parameters on admission to the intensive care unit (ICU) and their association with presence of sepsis and sepsis outcomes in anemic critically ill patients. We performed a retrospective observational study covering consecutive patients admitted to a 10-bed mixed ICU in the years 2020−2021. We found significant differences between septic and non-septic patients for the following parameters: RDW (p = 0.02), INR (p < 0.01), aPTT (p < 0.01), D-dimers (p < 0.01), fibrinogen (p = 0.02), platelets (p = 0.04). International normalized ratio was the only parameter with adequate sepsis predictive value (AUROC = 0.70; 95% CI 0.63−0.76; p < 0.01), with an optimal cut-off value of >1.21. Combination of INR with fibrinogen and a severity of disease score improved INR’s predictive value (AUROC 0.74−0.77). Combination of INR with a severity of disease score was an adequate ICU mortality predictor in septic patients (AUROC 0.70−0.75). Sepsis significantly affects RDW and most coagulation parameters. Increased INR can be used for sepsis screening, whereas combination of INR with a severity of disease score can be a predictor of short-term mortality in septic patients.

Nanotechnology-based advances in the efficient delivery of melatonin

N-[2-(5-methoxy-1H-indol-3-yl) ethyl] or simply melatonin is a biogenic amine produced by pineal gland and recently recognized various other organs. Because of a broad range of biological function melatonin is considered as a therapeutic agent with high efficacy in the treatment of multiple disorders, such as cancer, degenerative disorders and immune disease. However, since melatonin can affect receptors on the cellular membrane, in the nucleus and can act as an anti-oxidant molecule, some unwanted effects may be observed after administration. Therefore, the entrapment of melatonin in biocompatible, biodegradable and safe nano-delivery systems can prevent its degradation in circulation; decrease its toxicity with increased half-life, enhanced pharmacokinetic profile leading to improved patient compliance. Because of this, nanoparticles have been used to deliver melatonin in multiple studies, and the present article aims to cumulatively illustrate their findings.

Determination of Total Phenolic Content, Analysis of Bioactive Compound Components, and Antioxidant Activity of Ethyl Acetate Seri (Muntingia calabura L.) Leaves from North Sumatera Province, Indonesia

BACKGROUND: Seri (Muntingia calabura L.) leaves are a plant that is often found and have not been used in various treatments even though it is reported to have various groups of bioactive compounds such as phenolic, flavonoids, tannins, saponins, steroids, and triterpenoids. AIM: This study aimed to determine the total phenolic content, antioxidant activity and identify the content of potential bioactive compounds contained in the ethyl acetate fraction from M. calabura leaves. METHODS: M. calabura L. leaves fraction was carried out by maceration method using ethanol followed by partition starting with n-hexane, chloroform, and finally ethyl acetate as solvent. The ethyl acetate fraction was continued for phytochemical screening for the content of bioactive compounds using standard reagents, determination of total phenol content by colorimetric method, determination of antioxidant activity using the DPPH method, and analysis of bioactive compounds using gas chromatography–mass spectroscopy. RESULTS: The results showed that the ethyl acetate fraction of M. calabura leaves was positive for phenolic content which was indicated by the formation of a turquoise color after 5% FeCl3 reagent was added (in ethanol), phenolic content was 0.0727 mg GAE/g dry fraction, indicating antioxidant activity (IC50) amounted to 54.437 including strong categories as antioxidants and the results of GC–MS analysis obtained various kinds of compounds and it is suspected that compounds that provide potential as antioxidants are phytol. CONCLUSION: The bioactive compound of ethyl acetate fraction of seri (M. calabura) leaves contained phenolic components and has strong antioxidant activity.

Anagliptin prevents lipopolysaccharide (LPS)- induced inflammation and activation of macrophages

Sepsis is a multiple organ dysfunction syndrome (MODS) induced by infection, which significantly threatens public health. The overactivation of inflammatory reactions and oxidative stress participate in the pathogenesis of sepsis. Anagliptin, a novel anti-diabetic agent widely applied for the treatment of type II diabetes, has been recently claimed to possess anti-inflammatory properties. Here, the protective effects of anagliptin on lipopolysaccharide (LPS)- stimulated macrophages will be checked to explore the possible pharmacological property of anagliptin on sepsis. The state of oxidative stress was dramatically activated by LPS, accompanied by the upregulation of toll-like receptor 4 (TLR4) and high mobility group box-1 (HMGB-1), as well as the elevated expression of inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO). After treatment with anagliptin, the state of oxidative stress in macrophages was alleviated, with the downregulation of TLR4, HMGB-1, iNOS, and the declined release of NO. The excessive secretion of inflammatory factors, activation of the NF-κB pathway, and promoted expression level of receptor-interacting protein 1 (RIP1) were observed in LPS- stimulated macrophages, all of which were greatly reversed by the introduction of anagliptin. Lastly, the protective properties of anagliptin on LPS- treated macrophages, including the inhibitory effects on inflammation and the NF-κB pathway, were dramatically abolished by the overexpression of RIP1 in macrophages. Collectively, anagliptin prevented LPS-induced inflammation and activation of P338D1 macrophages by repressing the expression level of RIP1.

Red Cell Distribution Width as a Predictor of Mortality in Patients With Clinical Sepsis: Experience From a Single Rural Center in Central India

Introduction:

Early diagnosis of sepsis and its severity is essential for appropriate treatment to improve patient survival, especially in resource-limited settings. The aim of the present study was to study the role of red blood cell distribution (RDW) as a biomarker for the early detection of severe sepsis defined clinically and also in the prediction of mortality from sepsis.

Methods:

The cross-sectional study included a total of 175 subjects who met the inclusion criteria for the diagnosis of severe sepsis. After a thorough clinical examination, blood samples were taken from all patients within 3 hours of presenting the disease. The RDW values and other investigations were studied on the day of admission compared to other severity markers with the mortality index of 30 days.

Result:

The RDW value was significantly higher in patients with severe sepsis and in non-survivor patients than in survivors (P < .0001). There was a strong correlation between the SOFA score and RDW in predicting the disease outcome with the Pearson correlation coefficient of r = .46. The area under the receiver operating characteristic curve was found to be 0.852 at a CI of 95% (0.796-0.909) with RDW 17.15, sensitivity was 88.6% and specificity was 63.5%. There was a positive correlation with Pearson’s correlation coefficient of r = .46 between RDW and the SOFA score.

Conclusions:

RDW can be used as a potential marker for the early detection of severe sepsis and in the prediction of the outcome. Large multicenter prospective studies can confirm the utility of this routinely available marker for patients with sepsis.

Erythrocyte degradation, metabolism, secretion, and communication with immune cells in the blood during sepsis: A review

Sepsis is a health issue that affects millions of people worldwide. It was assumed that erythrocytes were affected by sepsis. However, in recent years, a number of studies have shown that erythrocytes affect sepsis as well. When a pathogen invades the human body, it infects the blood and organs, causing infection and sepsis-related symptoms. Pathogens change the internal environment, increasing the levels of reactive oxygen species, influencing erythrocyte morphology, and causing erythrocyte death, i.e., eryptosis. Characteristics of eryptosis include cell shrinkage, membrane blebbing, and surface exposure of phosphatidylserine (PS). Eryptotic erythrocytes increase immune cell proliferation, and through PS, attract macrophages that remove the infected erythrocytes. Erythrocyte-degraded hemoglobin derivatives and heme deteriorate infection; however, they could also be metabolized to a series of derivatives. The result that erythrocytes play an anti-infection role during sepsis provides new perspectives for treatment. This review focuses on erythrocytes during pathogenic infection and sepsis.

Selenocompounds and Sepsis: Redox Bypass Hypothesis for Early Diagnosis and Treatment: Part A-Early Acute Phase of Sepsis: An Extraordinary Redox Situation (Leukocyte/Endothelium Interaction Leading to Endothelial Damage)

Significance: Sepsis is a health disaster. In sepsis, an initial, beneficial local immune response against infection evolves rapidly into a generalized, dysregulated response or a state of chaos, leading to multiple organ failure. Use of life-sustaining supportive therapies creates an unnatural condition, enabling the complex cascades of the sepsis response to develop in patients who would otherwise die. Multiple attempts to control sepsis at an early stage have been unsuccessful. Recent Advances: Major events in early sepsis include activation and binding of leukocytes and endothelial cells in the microcirculation, damage of the endothelial surface layer (ESL), and a decrease in the plasma concentration of the antioxidant enzyme, selenoprotein-P. These events induce an increase in intracellular redox potential and lymphocyte apoptosis, whereas apoptosis is delayed in monocytes and neutrophils. They also induce endothelial mitochondrial and cell damage. Critical Issues: Neutrophil production increases dramatically, and aggressive immature forms are released. Leukocyte cross talk with other leukocytes and with damaged endothelial cells amplifies the inflammatory response. The release of large quantities of reactive oxygen, halogen, and nitrogen species as a result of the leukocyte respiratory burst, endothelial mitochondrial damage, and ischemia/reperfusion processes, along with the marked decrease in selenoprotein-P concentrations, leads to peroxynitrite damage of the ESL, reducing flow and damaging the endothelial barrier. Future Directions: Endothelial barrier damage by activated leukocytes is a time-sensitive event in sepsis, occurring within hours and representing the first step toward organ failure and death. Reducing or stopping this event is necessary before irreversible damage occurs.

Comparison of Protein Carbonyl (PCO), Paraoxonase-1 (PON1) and C-Reactive Protein (CRP) as Diagnostic and Prognostic Markers of Septic Inflammation in Dogs

Reliable diagnostic and prognostic markers of sepsis are lacking, but essential in veterinary medicine. We aimed to assess the accuracy of C-Reactive Protein (CRP), protein carbonyls (PCO) and paraoxonase-1 (PON1) in differentiating dogs with sepsis from those with sterile inflammation and healthy ones, and predict the outcome in septic dogs. These analytes were retrospectively evaluated at admission in 92 dogs classified into healthy, septic and polytraumatized. Groups were compared using the Kruskal–Wallis test, followed by a Mann–Whitney U test to assess differences between survivors and non-survivors. Correlation between analytes was assessed using the Spearman’s test, and their discriminating power was assessed through a Receiver Operating Characteristic (ROC) curve. PON1 and CRP were, respectively, significantly lower and higher in dogs with sepsis compared with polytraumatized and clinically healthy dogs (p < 0.001 for both the analytes), and also in dogs with trauma compared with healthy dogs (p = 0.011 and p = 0.017, respectively). PCO were significantly increased in septic (p < 0.001) and polytraumatized (p < 0.005) as compared with healthy dogs. PON1 and CRP were, respectively, significantly lower and higher in dogs that died compared with survivors (p < 0.001 for both analytes). Ultimately, evaluation of CRP and PON1 at admission seems a reliable support to diagnose sepsis and predict outcomes.

Cardiovascular Responses During Sepsis

Sepsis is the life-threatening organ dysfunction arising from a dysregulated host response to infection. Although the specific mechanisms leading to organ dysfunction are still debated, impaired tissue oxygenation appears to play a major role, and concomitant hemodynamic alterations are invariably present. The hemodynamic phenotype of affected individuals is highly variable for reasons that have been partially elucidated. Indeed, each patient's circulatory condition is shaped by the complex interplay between the medical history, the volemic status, the interval from disease onset, the pathogen, the site of infection, and the attempted resuscitation. Moreover, the same hemodynamic pattern can be generated by different combinations of various pathophysiological processes, so the presence of a given hemodynamic pattern cannot be directly related to a unique cluster of alterations. Research based on endotoxin administration to healthy volunteers and animal models compensate, to an extent, for the scarcity of clinical studies on the evolution of sepsis hemodynamics. Their results, however, cannot be directly extrapolated to the clinical setting, due to fundamental differences between the septic patient, the healthy volunteer, and the experimental model. Numerous microcirculatory derangements might exist in the septic host, even in the presence of a preserved macrocirculation. This dissociation between the macro- and the microcirculation might account for the limited success of therapeutic interventions targeting typical hemodynamic parameters, such as arterial and cardiac filling pressures, and cardiac output. Finally, physiological studies point to an early contribution of cardiac dysfunction to the septic phenotype, however, our defective diagnostic tools preclude its clinical recognition. © 2021 American Physiological Society. Compr Physiol 11:1605-1652, 2021.

Immune activation during Paenibacillus brain infection in African infants with frequent cytomegalovirus co-infection

Inflammation during neonatal brain infections leads to significant secondary sequelae such as hydrocephalus, which often follows neonatal sepsis in the developing world. In 100 African hydrocephalic infants we identified the biological pathways that account for this response. The dominant bacterial pathogen was a Paenibacillus species, with frequent cytomegalovirus co-infection. A proteogenomic strategy was employed to confirm host immune response to Paenibacillus and to define the interplay within the host immune response network. Immune activation emphasized neuroinflammation, oxidative stress reaction, and extracellular matrix organization. The innate immune system response included neutrophil activity, signaling via IL-4, IL-12, IL-13, interferon, and Jak/STAT pathways. Platelet-activating factors and factors involved with microbe recognition such as Class I MHC antigen-presenting complex were also increased. Evidence suggests that dysregulated neuroinflammation propagates inflammatory hydrocephalus, and these pathways are potential targets for adjunctive treatments to reduce the hazards of neuroinflammation and risk of hydrocephalus following neonatal sepsis.

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There is a characteristic immune response to Paenibacillus brain infection

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There is a characteristic immune response to CMV brain infection

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The matching immune response validates pathogen genomic presence

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The combined results support molecular infection causality

Sepsis impairs the propagation of cortical spreading depression in rats and this effect is prevented by antioxidant extract

Sepsis is a clinical syndrome with high morbidity and mortality. It is characterized by acute inflammatory response and oxidative stress, which is implicated in cerebral dysfunction. Murici (Byrsonimacrassifolia (L.) Kunth) is a fruit rich in antioxidant compounds, which could be an alternative to prevent damage to tissues induced by sepsis . Here, we evaluated the effects of sepsis on the propagation of cortical spreading depression (CSD) and oxidative stress, and tested the action of murici antioxidant extract in prevention against the effect of sepsis. Male Wistar rats (90-210 days, n = 40) were previously supplemented, orogastrically, with murici extract (150 mg/kg/day or 300 mg/kg/day), or an equivalent volume of the vehicle solution, for fifteen days. Then the animals were subjected to experimental sepsis through cecal ligation and perforation (CLP). Subsequently, CSD recordings were obtained and brain oxidative stress was evaluated. Sepsis decelerated CSD and increased the malondialdehyde (MDA) levels in the brain cortex of the animals. In contrast, septic rats that had been previously supplemented with murici antioxidant extract in doses of 150 and 300 mg/kg/day showed an increase in CSD propagation velocity, low levels of MDA and GSH/GSSG ratio and an increase of superoxide dismutase (SOD) activity, regardless of the dose tested. Our results demonstrate that sepsis affects brain excitability and that this effect can be prevented by murici antioxidant extract. The effects of sepsis and/or murici extract on CSD may be due to the oxidative state of the brain.

Reactive Oxygen Species Interact With NLRP3 Inflammasomes and Are Involved in the Inflammation of Sepsis: From Mechanism to Treatment of Progression

Over the past 10 years, the crisis of sepsis has remained a great challenge. According to data from 2016, the sepsis-related mortality rate remains high. In addition, sepsis consumes extensive medical resources in intensive care units, and anti-inflammatory agents fail to improve sepsis-associated hyperinflammation and symptoms of immunosuppression. The specific immune mechanism of sepsis remains to be elucidated. Reactive oxygen species (ROS) are triggered by energy metabolism and respiratory dysfunction in sepsis, which not only cause oxidative damage to tissues and organelles, but also directly and indirectly promote NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. NLRP3 inflammasomes enlarge the inflammatory response and trigger apoptosis of immune cells to exacerbate sepsis progression. Inhibiting the negative effects of ROS and NLRP3 inflammasomes therefore provides the possibility of reversing the excessive inflammation during sepsis. In this review, we describe the interaction of ROS and NLRP3 inflammasomes during sepsis, provide prevention strategies, and identify fields that need further study.

Ultrastructural Changes of Blood Cells in Children with Generalized Purulent Peritonitis: A Cross-Sectional and Prospective Study

In conditions of abdominal sepsis with indications of first- or second-stage shock, blood cells undergo significant ultrastructural changes that cause impaired gas exchange, changes in reactivity, and decompensation of organs and systems functions. This paper presents a cross-sectional prospective study aimed at researching the ultrastructure of blood cells in children experiencing abdominal septic shock against the background of generalized purulent peritonitis of appendicular origin. This study was conducted with 15 children aged 6-12 who were undergoing treatment for generalized appendicular purulent peritonitis, with first- or second-stage abdominal septic shock, in emergency care. The changes in the ultrastructure of erythrocytes did not correspond to changes characteristic of eryptosis, which confirms their occurrence under the influence of such pathogenic factors as intoxication, metabolic, water-electrolyte balance, and acid-base disorders. Ultrastructural changes of granulocytes indicate their hyperactivation, which leads to the exhaustion of membrane synthetic resources, membrane destruction, ineffective expenditure of bactericidal factors on substrates that are not subject to destruction. In lymphocytes, disorganization of the nuclear membrane and intracellular membranes, uneven distribution of chromatin, the hypertrophied Golgi apparatus, and a large number of young mitochondria, lysosomes, ribosomes, vesicles manifesting the disruption of metabolism, stress and decompensation of energy supply and protein synthesis systems, have been demonstrated. In conditions of abdominal sepsis with indications of first- or second-stage shock, blood cells undergo substantial ultrastructural changes causing gas exchange disruption, changes in reactivity, as well as decompensation of organs and system functioning.

SARS-CoV-2 infection pathogenesis is related to oxidative stress as a response to aggression

Since the WHO declared COVID-19 a pandemic, a great effort has been made to understand this serious disease. Thousands of studies are being devoted to understanding its epidemiology, its molecular characteristics, its mechanisms, and the clinical evolution of this viral infection. However, little has been published on its pathogenesis and the host response mechanisms in the progress of the disease. Therefore, we propose a hypothesis based on strong scientific documentation, associating oxidative stress with changes found in patients with COVID-19, such as its participation in the amplification and perpetuation of the cytokine storm, coagulopathy, and cell hypoxia. Finally, we suggest a therapeutic strategy to reduce oxidative stress using antioxidants, NF-κB inhibitors, Nrf2 activators, and iron complexing agents. We believe that this hypothesis can guide new studies and therapeutic strategies on this topic.

The effects of chrysin on lipopolysaccharide-induced sepsis in rats

Chrysin (CR) is a flavone found in propolis and many plants. Lipopolysaccharide (LPS) is a component of the cell wall of gram-negative bacteria that causes sepsis. The purpose of this study was to investigate the effects of CR on LPS-induced sepsis in rats. LPS intraperitoneal and a single dose and CR were given orally for 10 days. Rats were sacrificed, blood samples were taken, liver, lung, and kidney tissues were dissected, homogenized, and histopathological analysis was carried out. When CR groups compared to sepsis group, CR significantly decreased the serum levels of aspartate transaminase (AST) and alanine aminotransferase (ALT), interleukin-1 beta (IL-1β), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and levels of malondialdehyde (MDA) in tissues. CR also increased the levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in tissues. Histopathological findings were consistent with biochemical findings. Conclusion, CR could reduce the oxidative stress markers and cytokines in sepsis. PRACTICAL APPLICATIONS: Our approach is to determine the antioxidant and anti-inflammatory effects of chrysin, known as a flavolonoid, which are found in many plants and foods such as honey and propolis. In this study, experimental sepsis model was created using LPS. According to the results of the study, CR can attribute to the ameliorating of oxidative damage in tissues (lung, liver, and kidney) and it can suppress the sepsis-associated acute tissue injury via reduction of inflammation in rats. Even, CR can be used as a pharmacological agent in inflammatory diseases caused by other sources and in many cases causing oxidation.

Hyperoxia and antioxidants during major non-cardiac surgery and risk of cardiovascular events: Protocol for a 2 × 2 factorial randomised clinical trial

BACKGROUND

Myocardial injury after non-cardiac surgery occurs in a high number of patients, resulting in increased mortality in the post-operative period. The use of high inspiratory oxygen concentrations may cause hyperoxia, which is associated with impairment of coronary blood flow. Furthermore, the surgical stress response increases reactive oxygen species, which is involved in several perioperative complications including myocardial injury and death. Avoidance of hyperoxia and substitution of reactive oxygen species scavengers may be beneficial. Our primary objective is to examine the effect of oxygen and added antioxidants for prevention of myocardial injury assessed by area under the curve for troponin measurements during the first three post-operative days.

METHODS

The VIXIE trial (VitamIn and oXygen Interventions and cardiovascular Events) is an investigator-initiated, blinded, 2 × 2 factorial multicentre clinical trial. We include 600 patients with cardiovascular risk factors undergoing major non-cardiac surgery. Participants are randomised to an inspiratory oxygen fraction of 0.80 or 0.30 during and for 2 hours after surgery and either an intravenous bolus of vitamin C and an infusion of N-acetylcysteine or matching placebo of both. The primary outcome is the area under the curve for high-sensitive cardiac troponin release during the first three post-operative days as a marker of the extent of myocardial injury. Secondary outcomes are mortality, non-fatal myocardial infarction and non-fatal serious adverse events within 30 days.

PERSPECTIVE

The current trial will provide further evidence for clinicians on optimal administration of perioperative oxygen in surgical patients with cardiovascular risks and the clinical effects of two common antioxidants.

Therapeutic effects of curcumin on sepsis and mechanisms of action: A systematic review of preclinical studies

Sepsis is a complex disease that begins with an infectious disorder and causes excessive immune responses. Curcumin is considered as an active component of turmeric that can improve the condition in sepsis due to its anti-inflammatory and antioxidant properties. PubMed, Embase, Google Scholar, Web of Science, and Scopus databases were searched. Searching was not limited to a specific publication period. Only English-language original articles, which had examined the effect of curcumin on sepsis, were included. At first, 1,098 articles were totally found, and 209 articles were selected after excluding duplicated data; 46 articles were remained due to the curcumin effects on sepsis. These included 23 in vitro studies and 23 animal studies. Our results showed that curcumin and various analogs of curcumin can have an inhibitory effect on sepsis-induced complications. Curcumin has the ability to inhibit the inflammatory, oxidative coagulation factors, and regulation of immune responses in sepsis. Despite the promising evidence of the therapeutic effects of curcumin on the sepsis complication, further studies seem necessary to investigate its effect and possible mechanisms of action in human studies.

Clinical Trial Assessment of Intermittent and Continuous Infusion Dose of N-Acetylcysteine on Redox Status of the Body in Patients with Sepsis Admitted to the ICU

PURPOSE

Conflicting results exist regarding the efficacy of N-acetyl cysteine (NAC) in sepsis treatment. A pivotal factor affecting the therapeutic potency of NAC in sepsis is timing and dosing of its infusion. We aimed to assess the effect of NAC on redox status of patients with sepsis and to compare its efficacy in intermittent and continuous infusion with the objective of developing the infusion regimen and optimizing the timing.

MATERIALS AND METHODS

A prospective, randomized clinical trial was designed to compare the antioxidative effect of NAC in intermittent infusion group (IV: 25 mg/kg bolus and then 25 mg/kg/8 hours 3 times) and continuous infusion group (IV: 25 mg/kg bolus and then 75 mg/kg over 24 hours) in 60 critically ill patients with sepsis (20 patients in each group). Blood samples were collected immediately before and after intervention for total antioxidant capacity (TAC) and malondialdehyde (MDA) assessment.

RESULTS

N-acetyl cysteine considerably increased TAC levels in both intermittent (0.68 ± 0.60; P value = .036) and continuous (0.69 ± 0.64; P value = .015) infusion groups when compared to placebo (0.61 ± 0.10); however, the difference in TAC levels between the intermittent and the continuous infusion did not reach statistical significance (P value = .942). Likewise, NAC treatment decreased MDA levels in both intermittent (19.45 ± 4.18; P value = 0.001) and continuous (22.47 ± 6.68; P value = .002) infusion groups when compared to placebo (31.76 ± 11.06), while the difference in MDA levels between the intermittent and the continuous infusion did not reach statistical significance (P value = .481).

CONCLUSION

Our data confirmed the antioxidative effect of NAC treatment in patients with sepsis, with no significant difference in intermittent and continuous infusion.

Inflammasomes: Pandora's box for sepsis

Sepsis was known to ancient Greeks since the time of great physician Hippocrates (460-377 BC) without exact information regarding its pathogenesis. With time and medical advances, it is now considered as a condition associated with organ dysfunction occurring in the presence of systemic infection as a result of dysregulation of the immune response. Still with this advancement, we are struggling for the development of target-based therapeutic approach for the management of sepsis. The advancement in understanding the immune system and its working has led to novel discoveries in the last 50 years, including different pattern recognition receptors. Inflammasomes are also part of these novel discoveries in the field of immunology which are <20 years old in terms of their first identification. They serve as important cytosolic pattern recognition receptors required for recognizing cytosolic pathogens, and their pathogen-associated molecular patterns play an important role in the pathogenesis of sepsis. The activation of both canonical and non-canonical inflammasome signaling pathways is involved in mounting a proinflammatory immune response via regulating the generation of IL-1β, IL-18, IL-33 cytokines and pyroptosis. In addition to pathogens and their pathogen-associated molecular patterns, death/damage-associated molecular patterns and other proinflammatory molecules involved in the pathogenesis of sepsis affect inflammasomes and vice versa. Thus, the present review is mainly focused on the inflammasomes, their role in the regulation of immune response associated with sepsis, and their targeting as a novel therapeutic approach.

Effects of FM0807, a novel curcumin derivative, on lipopolysaccharide-induced inflammatory factor release via the ROS/JNK/p53 pathway in RAW264.7 cells

Purpose: Sepsis is a systemic inflammatory response caused by infection. Curcumin is known to have antioxidant and anti-inflammatory activities. FM0807, a curcumin derivative, was investigated in the present study to determine its effect on cytokines and the possible molecular mechanism. Main methods: The experiments were carried out in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Cell viability was measured by MTT assay. ELISA, Griess assays, fluorescence-based quantitative PCR, flow cytometric analysis, 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) experiments, and Western blotting were carried out to assess the potential effects of FM0807 on LPS-induced RAW 264.7 cells. Significant findings: FM0807 had no cytotoxic effects on RAW 264.7 cells. Furthermore, pretreatment with FM0807 inhibited the inflammatory factor tumor necrosis factor-α (TNF-α), interleukin (IL) 1β (IL-1β), IL-6, and inducible nitric oxide synthase (iNOS) at the protein and gene levels. FM0807 also inhibited the production of reactive oxygen species (ROS) and apoptosis. In addition, the activation of the ROS/JNK (c-jun NH₂-terminal kinase)/p53 signaling pathway was inhibited by FM0807 in RAW 264.7 cells in vitro. Conclusion: FM0807 has anti-inflammatory activity in vitro, which suggests a potential clinical application in sepsis. The anti-inflammatory activity of FM0807 may be mediated by the ROS/JNK/p53 signaling pathway.

T cells and their immunometabolism: A novel way to understanding sepsis immunopathogenesis and future therapeutics

Sepsis has always been considered as a big challenge for pharmaceutical companies in terms of discovering and designing new therapeutics. The pathogenesis of sepsis involves aberrant activation of innate immune cells (i.e. macrophages, neutrophils etc.) at early stages. However, a stage of immunosuppression is also observed during sepsis even in the patients who have recovered from it. This stage of immunosuppression is observed due to the loss of conventional (i.e. CD4⁺, CD8⁺) T cells, Th17 cells and an upregulation of regulatory T cells (Tregs). This process also impacts metabolic processes controlling immune cell metabolism called immunometabolism. The present review is focused on the T cell-mediated immune response, their immunometabolism and targeting T cell immunometabolism during sepsis as future therapeutic approach. The first part of the manuscripts describes an impact of sepsis on conventional T cells, Th17 cells and Tregs along with their impact on sepsis. The subsequent section further describes the immunometabolism of these cells (CD4⁺, CD8⁺, Th17, and Tregs) under normal conditions and during sepsis-induced immunosuppression. The article ends with the therapeutic targeting of T cell immunometabolism (both conventional T cells and Tregs) during sepsis as a future immunomodulatory approach for its management.

The Effect of Sepsis on the Erythrocyte

Sepsis induces a wide range of effects on the red blood cell (RBC). Some of the effects including altered metabolism and decreased 2,3-bisphosphoglycerate are preventable with appropriate treatment, whereas others, including decreased erythrocyte deformability and redistribution of membrane phospholipids, appear to be permanent, and factors in RBC clearance. Here, we review the effects of sepsis on the erythrocyte, including changes in RBC volume, metabolism and hemoglobin's affinity for oxygen, morphology, RBC deformability (an early indicator of sepsis), antioxidant status, intracellular Ca²⁺ homeostasis, membrane proteins, membrane phospholipid redistribution, clearance and RBC O₂-dependent adenosine triphosphate efflux (an RBC hypoxia signaling mechanism involved in microvascular autoregulation). We also consider the causes of these effects by host mediated oxidant stress and bacterial virulence factors. Additionally, we consider the altered erythrocyte microenvironment due to sepsis induced microvascular dysregulation and speculate on the possible effects of RBC autoxidation. In future, a better understanding of the mechanisms involved in sepsis induced erythrocyte pathophysiology and clearance may guide improved sepsis treatments. Evidence that small molecule antioxidants protect the erythrocyte from loss of deformability, and more importantly improve septic patient outcome suggest further research in this area is warranted. While not generally considered a critical factor in sepsis, erythrocytes (and especially a smaller subpopulation) appear to be highly susceptible to sepsis induced injury, provide an early warning signal of sepsis and are a factor in the microvascular dysfunction that has been associated with organ dysfunction.