Evaluation of oxidative stress and antioxidant status: Correlation with the severity of sepsis

Biomarkers in sepsis

Sepsis is a life-threatening condition characterized by dysregulated host response to infection leading to organ dysfunction. Despite advances in understanding its pathology, sepsis remains a global health concern and remains a major contributor to mortality. Timely identification is crucial for improving clinical outcomes, as delayed treatment significantly impacts survival. Accordingly, biomarkers play a pivotal role in diagnosis, risk stratification, and management. This review comprehensively discusses various biomarkers in sepsis and their potential application in antimicrobial stewardship and risk assessment. Biomarkers such as white blood cell count, neutrophil to lymphocyte ratio, erythrocyte sedimentation rate, C-reactive protein, interleukin-6, presepsin, and procalcitonin have been extensively studied for their diagnostic and prognostic value as well as in guiding antimicrobial therapy. Furthermore, this review explores the role of biomarkers in risk stratification, emphasizing the importance of identifying high-risk patients who may benefit from specific therapeutic interventions. Moreover, the review discusses the emerging field of transcriptional diagnostics and metagenomic sequencing. Advances in sequencing have enabled the identification of host response signatures and microbial genomes, offering insight into disease pathology and aiding species identification. In conclusion, this review provides a comprehensive overview of the current understanding and future directions of biomarker-based approaches in sepsis diagnosis, management, and personalized therapy.

Plasma Ascorbic Acid Levels in Critically Ill Pediatric Patients

Ascorbic acid, or vitamin C, is a physiological antioxidant that has been found to be deficient in critically ill adults with sepsis and acute respiratory distress system. In adults, ascorbic acid supplementation has been shown to reduce the need for vasopressors and mechanical ventilation. This study aimed to describe the prevalence of ascorbic acid deficiency in critically ill pediatric patients. This prospective, single-centered study analyzed 34 patients aged 1 month to 18 years old with septic shock and/or acute respiratory failure requiring mechanical ventilation in a quaternary, urban, pediatric intensive care unit. Plasma ascorbic acid levels were measured by high-performance liquid chromatography within 24 hours of meeting eligibility criteria. The median level was 23.34 µM (IQR [11.45, 39.14]). Twenty-three patients had repeat samples that were collected 3 to 5 days later. The median for repeat samples was higher at 42.41 µM (IQR [13.08, 62.43]). Patients who were enterally fed had significantly higher levels than those who were not (62.4 ± 7.7 µM vs. 32.4 ± 7.1 µM; p  = 0.03). Ascorbic acid levels vary widely among critically ill children with septic shock and/or respiratory failure requiring mechanical ventilation, but one-half of our patients had deficient levels that are typically seen in scurvy. Further studies are warranted to investigate the significance of low levels as well as the impact of normalizing levels through nutritional support.

Geranylgeranylacetone mitigates sepsis-associated intestinal injury through CHIP-dependent anti-inflammation and anti-oxidative effect

Geranylgeranylacetone (GGA), an isoprenoid compound widely utilized as an antiulcer agent in Asia, confers protection against ischemia, anoxia, and oxidative stress by rapidly enhancing the expression of HSP70. Nevertheless, the impact of GGA on sepsis-associated intestinal injury remains unexplored. Thus, this study is crafted to elucidate the protective efficacy and underlying mechanisms of GGA against septic intestinal damage. Our findings revealed that GGA significantly extended the survival duration of septic mice, and mitigated lipopolysaccharide (LPS)-induced alterations in intestinal permeability and tissue damage. Furthermore, GGA effectively suppressed LPS-induced cytokine release, attenuated levels of reactive oxygen species (ROS) and malondialdehyde, and bolstered antioxidant-related parameters within the intestinal tissue of LPS-stimulated mice. Mechanistically, GGA significantly increased HSP70 expression and promoted E3 ubiquitin ligase CHIP to play the role in ubiquitination and degradation of karyopherin-α2 (KPNA2), resulting in inhibition of nuclear translocation of NF-κB and reduced NOX1, NOX2 and NOX4 expression. The inhibitory action of GGA on cytokine release and ROS generation was abolished by CHIP knockdown in IEC-6 cells treated with LPS. Simultaneously, the downregulation of CHIP reversed the suppressive role of GGA in the LPS-induced NF-κB activation and the expression of NOX1, NOX2 and NOX4 in IEC-6 cells. The effects of GGA on mitigating intestinal damage, inflammation and oxidative stress caused by LPS were eliminated in CHIP knockout mice. Our results demonstrate that the protective effect of GGA against LPS-caused intestinal injury of mice is dependent on CHIP activation, which promotes KPNA2 degradation and restrains translocation of NF-κB into nucleus, leading to suppressing LPS-induced inflammatory response and oxidative stress.

Investigation of the protective activity of baicalein on the lungs via regulation of various cellular responses in rats exposed to experimental sepsis

Backgrounds

In the present study, a cecal ligation and puncture (CLP)-induced experimental sepsis rat model was used to explore the effects of baicalein on inflammatory cytokine levels and oxidative stress as well as the possible regulatory role of nuclear factor-kappa B (NF-κB).

Methods

For that purpose, 42 Wistar albino rats were equally divided into control, sham, sepsis, B50 + S, B100 + S, S + B50, and S + B100 groups. The B50 + S and B100 + S groups received baicalein before the induction of sepsis, while the S + B50 and S + B100 groups received baicalein afterwards. Experimental sepsis in related groups is generated through ligation of cecum and a puncture in cecal wall. Serum samples were used for tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) analyses, and tissue Malondialdehyde (MDA), Superoxide dismutase (SOD), Glutathione (GSH), IL-6, and NF-κB levels were measured.

Results

Compared to the control group, there were significantly increases in the serum TNF-α, IL-6, tissue MDA, and NF-κB levels and decreases in the tissue SOD and GSH levels in the septic group (P < 0.05). Compared to the septic group, inflammation and oxidative stress were reduced in the baicalein-treated groups. Although all of the pre- and post-treatment protocols alleviated inflammation and oxidative stress to varying degrees, pre-treatment with 100 mg/kg was the most successful.

Conclusions

Findings of this study indicated that baicalein has the potential to reduce sepsis-related oxidative stress and inflammation in the lungs and that pathological outcomes could be regulated via NF-κB transcription factor activity.

Vitexin along with verapamil downregulates efflux pump P-glycoprotein in macrophages and potentiate M1 to M2 switching via TLR4-NF-κB-TNFR2 pathway in lipopolysaccharide treated mice

The lipopolysaccharide, a microbial toxin, is one of the major causative agents of sepsis. P-gp expression and its functions are altered during inflammation. LPS has been known to impair the functions of P-gp, an efflux transporter. But the effect of LPS on P-gp expression in murine peritoneal macrophages is poorly understood. Molecular docking studies reveal that vitexin is a potent substrate and verapamil a potent inhibitor of P-gp. In the present experimental study, the curative potential of vitexin as a fruit component and verapamil treated as a control inhibitor of P-gp was examined in a murine LPS sepsis model. The effects of vitexin and verapamil on P-gp expression in macrophages correlating with changes in macrophage polarization and associated functional responses during LPS induced sepsis were studied. Peritoneal macrophages of LPS (10 mg/kg body weight) challenged mice exhibited elevated levels of H2O2, superoxide, and NO in parallel with lower antioxidant activity. LPS treatment increased P-gp expression through increased TLR4/expression. However, LPS challenged mice treated with vitexin (5 mg/kg body weight) + verapamil (5 mg/kg body weight) showed higher anti-oxidant enzyme activity (SOD, CAT and GRx) resulting in reduced oxidative stress. This combination treatment also elevated TNFR2, concomitant with down-regulation of TLR4, NF-κB and P-gp expression in murine peritoneal macrophages, resulting in a switch from M1 to M2 polarisation of macrophages and reduced inflammatory responses. In conclusion, combined vitexin and verapamil treatment could be used as a promising therapy to regulate P-gp expression and protection against LPS mediated sepsis and inflammatory damages.

Free Radicals, Mitochondrial Dysfunction and Sepsis-induced Organ Dysfunction: A Mechanistic Insight

Sepsis is a complex clinical condition and a leading cause of death worldwide. During Sepsis, there is a derailment in the host response to infection, which can progress to severe sepsis and multiple organ dysfunction or failure, which leads to death. Free radicals, including reactive oxygen species (ROS) generated predominantly in mitochondria, are one of the key players in impairing normal organ function in sepsis. ROS contributing to oxidative stress has been reported to be the main culprit in the injury of the lung, heart, liver, kidney, gastrointestinal, and other organs. Here in the present review, we describe the generation, and essential properties of various types of ROS, their effect on macromolecules, and their role in mitochondrial dysfunction. Furthermore, the mechanism involved in the ROS-mediated pathogenesis of sepsis-induced organ dysfunction has also been discussed.

A comprehensive insight into the molecular and cellular mechanisms of action of resveratrol on complications of sepsis a systematic review

Sepsis and septic shock are still one of the most important medical challenges. Sepsis is an extreme and uncontrolled response of the innate immune system to invading pathogenesis. Resveratrol (3,5,4'-trihydroxytrans-stilbene), is a phenolic and non-flavonoid compound naturally produced by some plants and fruits. The object of the current study is to systematically review the impacts of resveratrol and its mechanisms of function in the management of sepsis and its related complications. The guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements were applied to perform the study (PROSPERO: CRD42021289357). We searched Embase, Web of Science, Google Scholar, Science Direct, PubMed, ProQuest, and Scopus databases up to January 2023 by using the relevant keywords. Study criteria were met by 72 out of 1415 articles screened. The results of this systematic review depict that resveratrol can reduces the complications of sepsis by affecting inflammatory pathways, oxidative stress, and modulating immune responses. Future human randomized clinical trials are necessary due to the promising therapeutic effects of resveratrol on sepsis complications and the lack of clinical trials in this regard.

Oxidative stress and DNA damage in critically ill patients with sepsis

The aim of our study was to assess the oxidative stress and inflammatory status in critically ill patients with sepsis as well as their relationship with the level of DNA damage. The study also evaluated the influence of all analyzed parameters on the outcome of the patients. The study included 27 critically ill patients with sepsis and 20 healthy subjects. Comet Assay was used for the measurement of the level of DNA damage, expressed as genetic damage index (GDI). Both oxidative stress parameters and the antioxidant parameters were obtained spectrophotometrically. The standard laboratory methods and the appropriate autoanalyzers were performed for determination the parameters of inflammation. A higher level of oxidative stress and more pronounced inflammation were found in the patients with sepsis compared to healthy subjects. The activity of the antioxidant enzymes was statistically declined in patients with sepsis, so that the most notable differences between two groups of participants were found for the activity of superoxide dismutase (SOD) (p = 0.004). Comet assay indicated that patients with sepsis had significantly higher GDI compared to healthy subjects (p < 0.001), which positively correlated with the concentration of superoxide anion radical (О₂^-) (r = 0.497, p = 0.010), and nitrites (NО₂^-) (r = 0.473, p = 0.015), as well with the concentration of C reactive protein (CRP) (r = 0.460, p = 0.041). Regression analysis confirmed that patients' age (p = 0.033), the level of О₂^- (p = 0.007), CRP concentration (p = 0.029) and GDI (p = 0.001) increased the risk of lethal outcome in critically ill patients with sepsis. In conclusion, critically ill patients with sepsis have a higher degree of oxidative stress and inflammation which contribute to a higher level of DNA damage. Consequently, above mentioned parameters, including patients' age, adversely affect the outcome of critically ill patients with sepsis.

Effect of Sulforaphane on cardiac injury induced by sepsis in a mouse model: Role of toll-like receptor 4

As sepsis is associated with a 50% increase in mortality, sepsis-induced cardiomyopathy has become a critical topic. A multidisciplinary approach is required for the diagnosis and treatment of septic cardiomyopathy. This study looked at Sulforaphane, a natural product that aims to evaluate cardiac function after sepsis, and its likely mechanism of action. Twenty-four adult male Swiss albino mice were randomly divided into 4 equal groups (n=6): sham, CLP, vehicle Sulforaphane (the same amount of DMSO injected IP one hour before the CLP), and Sulforaphane group (one hour before the CLP, a 5mg/kg dose of Sulforaphane was injected). Cardiac tissue levels of toll-like receptor 4 (TLR-4), pro-inflammatory mediators, anti-inflammatory markers, oxidative stress markers, apoptosis markers, and serum cardiac damage biomarkers were assessed using ELISA. Statistical analyses, including t-tests and ANOVA tests, were performed with a significance level of 0.05 for normally distributed data. Compared to the sham group, the sepsis group had significantly elevated levels of TLR-4, IL-6, TNF-α, MIF, F2-isoprostane, caspase-3, cTn-I, and CK-MB (p<0.05). In contrast, the Sulforaphane pre-treated group demonstrated significantly lower levels of these markers (p<0.05). Additionally, Bcl-2 levels were significantly reduced (p<0.05) in the Sulforaphane group. Sulforaphane administration also significantly attenuated cardiac tissue injury (p<0.05). The findings suggest that Sulforaphane can decrease heart damage in male mice during CLP-induced polymicrobial sepsis by suppressing TLR-4/NF-kB downstream signal transduction pathways.

Generalized precursor prediction boosts identification rates and accuracy in mass spectrometry based proteomics

Data independent acquisition mass spectrometry (DIA-MS) has recently emerged as an important method for the identification of blood-based biomarkers. However, the large search space required to identify novel biomarkers from the plasma proteome can introduce a high rate of false positives that compromise the accuracy of false discovery rates (FDR) using existing validation methods. We developed a generalized precursor scoring (GPS) method trained on 2.75 million precursors that can confidently control FDR while increasing the number of identified proteins in DIA-MS independent of the search space. We demonstrate how GPS can generalize to new data, increase protein identification rates, and increase the overall quantitative accuracy. Finally, we apply GPS to the identification of blood-based biomarkers and identify a panel of proteins that are highly accurate in discriminating between subphenotypes of septic acute kidney injury from undepleted plasma to showcase the utility of GPS in discovery DIA-MS proteomics.

Liver proteomic analysis reveals the key proteins involved in host immune response to sepsis

Background

Sepsis is a serious infection-induced response in the host, which can result in life-threatening organ dysfunction. It is of great importance to unravel the relationship between sepsis and host immune response and its mechanisms of action. Liver is one of the most vulnerable organs in sepsis, however, the specific pathogenesis of septic liver injury has not been well understood at the protein level.

Methods

A total of 12 healthy Sprague-Dawley (SD) male rats aged from 6 to 8 weeks were adaptively housed in individual cages in the specific pathogen free animal room. These lab rats were grouped into two groups: treatment (N = 9) and control (N = 3) groups; only three mice from the treatment group survived and were used for subsequent experiments. A TMT-based proteomic analysis for liver tissue was performed in the septic rat model.

Results

A total of 37,012 unique peptides were identified, and then 6,166 proteins were determined, among which 5,701 were quantifiable. Compared to the healthy control group, the septic rat group exhibited 162 upregulated and 103 downregulated differentially expressed proteins (DEPs). The upregulated and downregulated DEPs were the most significantly enriched into the complement and coagulation cascades and metabolic pathways. Protein-protein interaction (PPI) analysis further revealed that the upregulated and downregulated DEPs each clustered in a PPI network. Several highly connected upregulated and downregulated DEPs were also enriched into the complement and coagulation cascades pathways and metabolic pathways, respectively. The parallel reaction monitoring (PRM) results of the selected DEPs were consistent with the results of the TMT analysis, supporting the proteomic data.

Conclusion

Our findings highlight the roles of complement and coagulation cascades and metabolic pathways that may play vital roles in the host immune response. The DEPs may serve as clinically potential treatment targets for septic liver injury.

Effects of luteolin on sepsis: A comprehensive systematic review

BACKGROUND

Sepsis and septic shock are the main causes of mortality and complications in intensive care units all over the world. Luteolin is thought to have a significant role as a free radical scavenger, an anti-inflammatory agent, and an immune system modulator. The object of this review is to conduct a systematic review of the effects of luteolin and its mechanisms of action in the treatment of sepsis and its complications.

METHOD

The investigation was carried out in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines (PROSPERO: CRD42022321023). We searched Embase, Web of Science, Google Scholar, Science Direct, PubMed, ProQuest, and Scopus databases up to  January 2023 by using the relevant keywords.

RESULTS

Out of 1,395 records screened, 33 articles met the study criteria. In the collected papers, the main reported findings are that luteolin can affect inflammation-initiating pathways such as toll-like receptors and high mobility group box-1 and reduces the expression of genes that produce inflammatory cytokines, such as the Nod receptor protein-3, and nuclear factor kappa-light chain-enhancer of activated B cells. Luteolin also reduces the overactivity of macrophages, neutrophil extracellular traps and lymphocytes by regulating the immune response.

CONCLUSION

Most studies revealed luteolin's positive benefits on sepsis through several pathways. Luteolin showed the capacity to reduce inflammation and oxidative stress, control immunological response, and prevent organ damage (in vivo studies) during sepsis. Large-scale in vivo experiments are necessary to elucidate its potential impacts on sepsis.

High Concentration Hydrogen Mitigates Sepsis-Induced Acute Lung Injury in Mice by Alleviating Mitochondrial Fission and Dysfunction

Background: Multiple organ failure (MOF) is the main cause of early death in septic shock. Lungs are among the organs that are affected in MOF, resulting in acute lung injury. A large number of inflammatory factors and stress injury in sepsis can lead to alterations in mitochondrial dynamics. Numerous studies have confirmed that hydrogen can alleviate sepsis in the animal model. The purpose of this experiment was to explore the therapeutic effect of high concentration (67%) hydrogen on acute lung injury in septic mice and its mechanism. Methods: The moderate and severe septic models were prepared by cecal ligation and puncture. Hydrogen with different concentrations was inhaled for one hour at 1 h and 6 h after the corresponding surgery. The arterial blood gas of mice during hydrogen inhalation was monitored in real time, and the 7-day survival rate of mice with sepsis was recorded. The pathological changes of lung tissues and functions of livers and kidneys were measured. The changes of oxidation products, antioxidant enzymes and pro-inflammatory cytokines in lungs and serums were detected. Mitochondrial function was measured. Results: The inhalation of 2% or 67% hydrogen improves the 7-day survival rate and reduces acute lung injury as well as liver and kidney injury in sepsis. The therapeutic effect of 67% hydrogen inhalation on sepsis was related to increasing antioxidant enzyme activity, reducing oxidation products and pro-inflammatory cytokines in lungs and serums. Compared with the Sham group, mitochondrial dysfunction was alleviated in hydrogen groups. Conclusions: Hydrogen inhalation by high or low concentration can both significantly improve sepsis; however, a high concentration demonstrates a better protective effect. High concentration hydrogen inhalation can significantly improve the mitochondrial dynamic balance and reduce the lung injury in septic mice.

Novel Hybrid Indole-Based Caffeic Acid Amide Derivatives as Potent Free Radical Scavenging Agents: Rational Design, Synthesis, Spectroscopic Characterization, In Silico and In Vitro Investigations

Antioxidant small molecules can prevent or delay the oxidative damage caused by free radicals. Herein, a structure-based hybridization of two natural antioxidants (caffeic acid and melatonin) afforded a novel hybrid series of indole-based amide analogues which was synthesized with potential antioxidant properties. A multiple-step scheme of in vitro radical scavenging assays was carried out to evaluate the antioxidant activity of the synthesized compounds. The results of the DPPH assay demonstrated that the indole-based caffeic acid amides are more active free radical scavenging agents than their benzamide analogues. Compared to Trolox, a water-soluble analogue of vitamin E, compounds 3a, 3f, 3h, 3j, and 3m were found to have excellent DPPH radical scavenging activities with IC₅₀ values of 95.81 ± 1.01, 136.8 ± 1.04, 86.77 ± 1.03, 50.98 ± 1.05, and 67.64 ± 1.02 µM. Three compounds out of five (3f, 3j, and 3m) showed a higher capacity to neutralize the radical cation ABTS^•+ more than Trolox with IC₅₀ values of 14.48 ± 0.68, 19.49 ± 0.54, and 14.92 ± 0.30 µM, respectively. Compound 3j presented the highest antioxidant activity with a FRAP value of 4774.37 ± 137.20 μM Trolox eq/mM sample. In a similar way to the FRAP assay, the best antioxidant activity against the peroxyl radicals was demonstrated by compound 3j (10,714.21 ± 817.76 μM Trolox eq/mM sample). Taken together, compound 3j was validated as a lead hybrid molecule that could be optimized to maximize its antioxidant potency for the treatment of oxidative stress-related diseases.

A cross-sectional study to correlate antioxidant enzymes, oxidative stress and inflammation with prevalence of hypertension

AIMS

Hypertension a multifactorial consequence of environmental factors, life style and genetics is the well-recognized risk factor contributing to coronary heart diseases. The antioxidant imbalance, excessive reactive oxygen species (ROS) leads to oxidative stress which is pivotal in progression of hypertension. The present study aims to understand the complex interaction between oxidative stress, inflammation and antioxidant system which is crucial to maintain cellular homeostasis which further can exaggerate hypertension pathophysiology.

MATERIALS AND METHODS

The metabolic profile of hypertensive and normotensive subjects from Malwa region, Punjab was compared by estimating lipid profile, cardiac, hepatic and renal markers. The oxidative stress markers (protein carbonyls and lipid peroxidation), inflammatory markers (Nitric oxide, Myeloperoxidase and advanced oxygen protein products), and antioxidant enzymes (Superoxide Dismutase, Catalase, and Total Antioxidant Capacity) were analyzed.

KEY FINDINGS

It is observed that the metabolic markers are altered in hypertensive subjects which further these subjects showed increased oxidative, inflammatory profile and compromised antioxidant status when compared with normotensive subjects. Co-relation analysis validated the involvement of inflammation and oxidative stress in impaired endothelial function and vital organ damage.

SIGNIFICANCE OF STUDY

These markers may act as early indicators of hypertension which usually do not show any physical symptoms, thus can be diagnosed and treated at the earliest. The current study suggests that disturbed homeostasis, a consequence of altered interaction between antioxidant system and inflammatory events raises the oxidative stress levels which eventually leads to hypertension and associated complications. These indicators can serve as early indicators of future chronic complications of hypertension.

Thiol-Disulfide Homeostasis in Neonatal Patients with Urinary Tract Infection

OBJECTIVE

Urinary tract infection (UTI) is a disease that can cause significant complications in the neonatal period. The thiol-disulfide homeostasis is one of the important antioxidant defense mechanisms. The purpose of this study is to show the relationship between UTI and thiol-disulfide homeostasis in newborns.

STUDY DESIGN

In this prospective study, 40 newborns with UTI and 40 healthy controls were included. Thiol-disulfide tests (disulfide, native thiol, and total thiol levels) and septic screening tests were performed before and after antibiotherapy in UTI group. The control group was selected from healthy newborns who applied to the outpatient clinic.

RESULTS

The C-reactive protein and interleukin-6 levels were higher, while native thiol and native thiol/total thiol ratio were significantly lower in pretreatment group compared with posttreatment and control group. Also, the levels of disulfide, ischemia modified albumin, disulfide/native thiol ratio, and disulfide/total thiol ratio were higher in pretreatment group compared with posttreatment group.

CONCLUSION

The thiol-disulfide homeostasis is an important indicator of oxidative stress during infections. It is valuable to be detected with small amounts of serum in newborns. These molecules can be used to support the diagnosis of UTI in the newborn. Further studies are needed to define the role of thiol-disulfide homeostasis in the UTI of newborn.

KEY POINTS

· The thiol-disulfide homeostasis can be an important indicator of oxidative stress during infections such as UTI.. · The thiol-disulfide homeostasis of newborn is valuable to be detected with small amounts of serum in neonatal period.. · Laboratory tests such as white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are not significantly different in UTIs..

Unravelling the Differential Host Immuno-Inflammatory Responses to Staphylococcus aureus and Escherichia coli Infections in Sepsis

Previous reports from our lab have documented dysregulated host inflammatory reactions in response to bacterial infections in sepsis. Both Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB) play a significant role in the development and progression of sepsis by releasing several virulence factors. During sepsis, host cells produce a range of inflammatory responses including inducible nitric oxide synthase (iNOS) expression, nitrite generation, neutrophil extracellular traps (NETs) release, and pro-inflammatory cytokines production. The current study was conducted to discern the differences in host inflammatory reactions in response to both Escherichia coli and Staphylococcus aureus along with the organ dysfunction parameters in patients of sepsis. We examined 60 ICU sepsis patients identified based on the Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA II) scores. Pathogen identification was carried out using culture-based methods and gene-specific primers by real-time polymerase chain reaction (RT-PCR). Samples of blood from healthy volunteers were spiked with E. coli (GNB) and S. aureus (GPB). The incidence of NETs formation, iNOS expression, total nitrite content, and pro-inflammatory cytokine level was estimated. Prevalence of E. coli, A. baumannii (both GNB), S. aureus, and Enterococcus faecalis (both GPB) was found in sepsis patients. Augmented levels of inflammatory mediators including iNOS expression, total nitrite, the incidence of NETs, and proinflammatory cytokines, during spiking, were found in response to S. aureus infections in comparison with E. coli infections. These inflammatory mediators were found to be positively correlated with organ dysfunction in both GN and GP infections in sepsis patients. Augmented host inflammatory response was generated in S. aureus infections as compared with E. coli.

The Interplay of Oxidative Stress and ROS Scavenging: Antioxidants as a Therapeutic Potential in Sepsis

Oxidative stress resulting from the disproportion of oxidants and antioxidants contributes to both physiological and pathological conditions in sepsis. To combat this, the antioxidant defense system comes into the picture, which contributes to limiting the amount of reactive oxygen species (ROS) leading to the reduction of oxidative stress. However, a strong relationship has been found between scavengers of ROS and antioxidants in preclinical in vitro and in vivo models. ROS is widely believed to cause human pathology most specifically in sepsis, where a small increase in ROS levels activates signaling pathways to initiate biological processes. An inclusive understanding of the effects of ROS scavenging in cellular antioxidant signaling is essentially lacking in sepsis. This review compiles the mechanisms of ROS scavenging as well as oxidative damage in sepsis, as well as antioxidants as a potent therapeutic. Direct interaction between ROS and cellular pathways greatly affects sepsis, but such interaction does not provide the explanation behind diverse biological outcomes. Animal models of sepsis and a number of clinical trials with septic patients exploring the efficiency of antioxidants in sepsis are reviewed. In line with this, both enzymatic and non-enzymatic antioxidants were effective, and results from recent studies are promising. The usage of these potent antioxidants in sepsis patients would greatly impact the field of medicine.

Proinflammatory cytokines levels in sepsis and healthy volunteers, and tumor necrosis factor-alpha associated sepsis mortality: A systematic review and meta-analysis

BACKGROUND

Sepsis is a global health challenge associated with significant morbidity and mortality. Detrimental sepsis effects are attributed to excessive inflammation or a "cytokine storm." However, anti-inflammation therapies have failed to lower sepsis mortality. We aim to characterize levels of key inflammatory cytokines in patients with sepsis and compare levels with those in healthy individuals and relate tumor necrosis factor (TNF) α levels to patient characteristics and outcomes.

METHODS

We performed a systematic review and meta-analysis. Medline, Embase, Cochrane Library, and Web of Science Core Collection databases were searched between 1985 and May 2020. Analysis was restricted to studies in English. We included randomized controlled trials (RCTs), controlled trials, cohort studies, case series, and cross-sectional studies that reported mean levels of cytokines in the circulation thought to be relevant for sepsis pathogenesis. We also evaluated concentrations of these cytokines in healthy individuals. The Quality in Prognosis Studies tool was used to assess the methodological quality of included studies. We extracted summary data from published reports. Data analyses were performed using a random-effects model to estimate pooled odds ratios (OR) with 95% confidence intervals for cytokine levels and mortality. This systematic review is registered in PROSPERO (CRD42020179800).

FINDINGS

We identified 3654 records, and 104 studies were included with a total of 3250 participants. The pooled estimated mean TNFα concentration in sepsis patients was 58.4 pg/ml (95% Confidence Interval or CI 39.8-85.8 pg/ml), and in healthy individuals was 5.5 pg/ml (95% CI 3.8-8.0 pg/ml). Pooled estimate means for IL-1β and IFN-γ in sepsis patients were 21.8 pg/ml and 63.3 pg/ml, respectively. Elevated TNFα concentrations associated with increased 28-day sepsis mortality (p = 0.001). In subgroup analyses, we did not detect an association between TNFα levels and sepsis source, sepsis severity, or sequential organ failure assessment (SOFA) score. A TNF-α cutoff level ≥14.7 pg/ml separated sepsis patients from healthy individuals with a sensitivity of 82.6%, a specificity of 91.7%, and a likelihood ratio of 9.9.

INTERPRETATION

Sepsis mean TNFα concentration is increased approximately 10-fold compared to mean concentration in healthy individuals, and TNFα associated with sepsis mortality but not sepsis severity. The concept that elevated cytokines cause sepsis should be revisited in the context of these data.

FUNDING

None.

Comparison enteral superoxide dismutase 1 IU and 5 IU from Cucumis melo L.C extract combined with gliadin as an antioxidant and anti-inflammatory in LPS-Induced sepsis model rats

Sepsis is a major cause of death in intensive care units whose development is supported by an imbalance of oxidative stress and antioxidant. Superoxide dismutase (SOD) is a primer endogen antioxidant that prevents reactive oxygen species (ROS). Extensive studies on animals and humans have examined Cucumis melo L.C, a cantaloupe rich in SOD, and its combination with gliadin. The studies aimed to determine the effect of enteral administration of Cucumis melo L.C. gliadin (CME-gliadin) 28 days before inducing sepsis in rats. This experimental study aimed to compare four groups of male Wistar rats, including negative and positive control rats and those supplemented with SOD CME-gliadin 1 IU/day and SOD CME-gliadin 5 IU/day. All rats were given the same standard, except the supplementation for 28 days. Sepsis was induced by intraperitoneal injection of LPS 10 mg/kg. Enteral administration of SOD – gliadin extract of CME-gliadin for 28 days was used as antioxidant prophylaxis against oxidative stress due to sepsis. The results showed that enteral administration of CME-gliadin of 1 IU/day and 5 IU/day significantly increased SOD levels based on examination after 14 and 28 days. Also, it significantly decreased MDA (p < 0.001), TNF-α (p < 0.001), and lactate levels in rats induced by sepsis. However, the increase in lactate levels was above >1.64 mmol/l, indicating a high mortality rate. There was no significant difference in SOD, MDA, TNF-α, and Lactate levels between SOD 1 IU and SOD 5 IU. This descriptive data show that SOD 5 IU has a better result in MDA, TNF-α, and Lactate levels than SOD 1 IU.

Changes in Biomarkers of Redox Status in Saliva of Pigs after an Experimental Sepsis Induction

Saliva from pigs is gaining attention as an easy sample to obtain, being a source of biomarkers that can provide information on animal health and welfare. This study aimed to evaluate the changes that can occur in salivary biomarkers of the redox status of pigs with an experimentally induced sepsis. For that, the cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of saliva (FRAS), Trolox equivalent antioxidant capacity (TEAC), advanced oxidation protein products (AOPP), ferrous oxidation-xylenol orange (FOX), peroxide activity (POX-Act), and reactive oxygen-derived compounds (d-ROMs) were measured in the saliva of pigs with experimentally induced sepsis by endotoxin lipopolysaccharide (LPS), non-septic inflammation induced by turpentine, and in healthy individuals before and after 3 h, 6 h, 24 h, and 48 h. AOPP, POX-Act, and d-ROMs in the sepsis group were higher than in the control from 3 h to 24 h after the inoculation. CUPRAC, FRAS, and TEAC were higher in sepsis than the control group at 24 h. These changes were of higher magnitude than those that occurred in the turpentine group. In conclusion, our findings reveal that sepsis produces changes in salivary biomarkers of redox status, which opens the possibility of using them as potential biomarkers in this species.

Maackiain protects against sepsis via activating AMPK/Nrf2/HO-1 pathway

Sepsis is a life-threatening medical condition caused by infection-triggered aberrant immune responses, leading to host tissue and organ injury. Despite advances in medical interventions, the mortality rate for septic shock remains high. Recent studies highlight the role of oxidative stress in the occurrence and development of sepsis, providing a potential therapeutic target for preventing sepsis-associated organ injury. In this study, we showed that Maackiain, a natural compound isolated from Sophora flavescens, exerted a protective role in a cecal ligation and puncture (CLP)-induced murine model of sepsis. Maackiain treatment reduced organ injury, and mitigated systematic inflammation and oxidative stress in septic mice. Maackiain also reduced the levels of inflammatory cytokines and reactive oxygen species (ROS) in RAW264.7 macrophage cells stimulated with lipopolysaccharide (LPS). We further demonstrated that Maackiain initiated activation of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in RAW264.7 cells in an AMP-activated protein kinase (AMPK)-dependent way. Moreover, inhibition of AMPK/Nrf2 axis abrogated the anti-inflammatory and anti-oxidant effects of Maackiain both in vitro and in vivo. Collectively, our study indicates that Maackiain treatment inhibits inflammatory response and oxidative stress via activation of AMPK/Nrf2/HO-1 pathway, thus exerting a protective effect against sepsis, providing an alternative option for sepsis prevention.

Duchesnea indica Extract Ameliorates LPS-Induced Septic Shock in Mice

Objective

Duchesnea indica has been reported for its anti-inflammatory properties. However, its efficacy in sepsis has yet to be reported. In this study, we studied the ability of Duchesnea indica extract (DIE) to rescue mice from septic shock and sepsis.

Methods

In vitro studies included the measurement of secreted nitric oxide, cell viability, gene and protein expression via real-time polymerase chain reaction and western blot, and confocal microscopy in RAW 264.7 cells. In vivo studies include a model of septic shock and sepsis in BALB/c mice induced by a lethal and sub-lethal dose of lipopolysaccharide (LPS).

Results

DIE suppressed the expression of proinflammatory cytokines induced by LPS and prevented the translocation of NFκB into the nucleus of RAW 264.7 cells. It also prevented reactive oxygen species damage induced by LPS in murine bone marrow-derived macrophages. Models of sepsis and septic shock were established in BALB/c mice and DIE-rescued mice from septic shock. DIE also reversed the increase in tumor necrosis factor-α and nitrite levels in the serum of mice induced with sepsis. DIE also prevented the translocation of NFκB from the cytosol into the nucleus in murine lungs. Histopathological damage induced by sepsis was reversed in the testis, liver, and lungs of mice.

Conclusion

In conclusion, DIE is a suitable candidate for development as a therapeutic agent for sepsis.

Urine Hydrogen Peroxide Levels and Their Relation to Outcome in Patients with Sepsis, Septic Shock, and Major Burn Injury

Hydrogen peroxide (H2O2) and oxidative stress have been suggested as possible instigators of both the systemic inflammatory response and the increased vascular permeability associated with sepsis and septic shock. We measured H2O2 concentrations in the urine of 82 patients with severe infections, such as sepsis, septic shock, and infections not fulfilling sepsis-3 criteria, in patients with major burn injury with associated systemic inflammation, and healthy subjects. The mean concentrations of H2O2 were found to be lower in patients with severe infections compared to burn injury patients and healthy subjects. Patients with acute kidney injury (AKI), vs. those without AKI, in all diagnostic groups displayed higher concentrations of urine H2O2 (p < 0.001). Likewise, urine concentrations of H2O2 were higher in non-survivors as compared to survivors (p < 0.001) at day 28 in all diagnostic groups, as well as in patients with severe infections and burn injury (p < 0.001 for both). In this cohort, increased H2O2 in urine is thus associated with mortality in patients with sepsis and septic shock as well as in patients with burn injury.

Oxidant/Antioxidant Status Is Impaired in Sepsis and Is Related to Anti-Apoptotic, Inflammatory, and Innate Immunity Alterations

Oxidative stress is considered pivotal in the pathophysiology of sepsis. Oxidants modulate heat shock proteins (Hsp), interleukins (IL), and cell death pathways, including apoptosis. This multicenter prospective observational study was designed to ascertain whether an oxidant/antioxidant imbalance is an independent sepsis discriminator and mortality predictor in intensive care unit (ICU) patients with sepsis (n = 145), compared to non-infectious critically ill patients (n = 112) and healthy individuals (n = 89). Serum total oxidative status (TOS) and total antioxidant capacity (TAC) were measured by photometric testing. IL-6, -8, -10, -27, Hsp72/90 (ELISA), and selected antioxidant biomolecules (Ζn, glutathione) were correlated with apoptotic mediators (caspase-3, capsase-9) and the central anti-apoptotic survivin protein (ELISA, real-time PCR). A wide scattering of TOS, TAC, and TOS/TAC in all three groups was demonstrated. Septic patients had an elevated TOS/TAC, compared to non-infectious critically ill patients and healthy individuals (p = 0.001). TOS/TAC was associated with severity scores, procalcitonin, IL-6, -10, -27, IFN-γ, Hsp72, Hsp90, survivin protein, and survivin isoforms -2B, -ΔΕx3, -WT (p < 0.001). In a propensity probability (age-sex-adjusted) logistic regression model, only sepsis was independently associated with TOS/TAC (Exp(B) 25.4, p < 0.001). The AUC_TOS/TAC (0.96 (95% CI = 0.93–0.99)) was higher than AUC_TAC (z = 20, p < 0.001) or AUC_TOS (z = 3.1, p = 0.002) in distinguishing sepsis. TOS/TAC, TOS, survivin isoforms -WT and -2B, Hsp90, IL-6, survivin protein, and repressed TAC were strong predictors of mortality (p < 0.01). Oxidant/antioxidant status is impaired in septic compared to critically ill patients with trauma or surgery and is related to anti-apoptotic, inflammatory, and innate immunity alterations. The unpredicted TOS/TAC imbalance might be related to undefined phenotypes in patients and healthy individuals.

The Effect of Superoxide Dismutase on Inhibition of Acute Kidney Injury Induced by Sepsis Based on Kidney Tissue Histology and Murine Sepsis Score

Sepsis is one of the leading causes contributing to the incidence of acute kidney injury (AKI). Oxidative stress can be used as the main approach against sepsis-induced AKI. One of the primary antioxidants that plays a role in warding off oxidative stress is superoxide dismutase (SOD). This research aimed to observe the effect of antioxidant SOD in inhibiting sepsis in AKI based on kidney tissue histopathology. The research method was an experimental laboratory with a post-test-only control group design. Twenty-five adult male rats aged 12–16 weeks, weighing between 200 and 250 g, were randomly divided into five groups: Group I, as a positive control, where rats were injected with lipopolysaccharides (LPS); Group II, as a negative control; Group III, as treatment 1, where rats were injected with LPS and administered orally with SOD (Glisodin®) 250 IU daily; Group IV, as treatment 2, where rats were injected with LPS and administered orally with SOD (Glisodin®) 500 IU daily; and Group V, as treatment 2, where rats were injected with LPS and administered orally with SOD (Glisodin®) 1000 IU daily. Rats were administered with SOD (Glisodin®) by oral gavage with a flexible feeding tube for 16 weeks, given once daily in the morning, and then injected with LPS of 10 mg/kg body weight. Glisodin SOD had a significant effect on murine sepsis score (MSS). MSS influenced the tubular injury score linearly. We conclude that the optimal dose of SOD at 1000 IU for inhibiting sepsis-induced AKI incidence is compared to SOD at a dose of 250 and 500 IU. The antioxidant effect of SOD can prevent sepsis-induced AKI with oxidative stress events.

Isolation, identification, and activity evaluation of antioxidant components from Inula viscosa: A bioguided approach

Oxidative stress is linked to several invasive diseases which causes significant clinical and economic impact, therefore, there is a need to develop new antioxidants. The natural products could play an important role in overcoming the current need. In the present work, the antioxidant bioassay-guided fractionation of the ethanolic extract of Inula viscosa leaves (Asteraceae) was performed using DPPH and ABTS assays affording three known compounds, which were successfully characterized as ilicic acid (1), taxifolin (2) and quercetin (3) based on 1D, 2D NMR. Compounds 2 and 3 were identified as the most active, displaying similar or higher potency against ABTS (value 41.27 for quercetin and 142.58 for taxifolin) and similar activity against DPPH (value 41.27 for quercetin and 142.58 for taxifolin) than the well-known reference, ascorbic acid (value 65.36 for quercetin and 58.43 for taxifolin) but less potency than the standard gallic acid. The discussion of SAR of the antioxidant potential revealed that the type of natural product is crucial for the activity and the substitution pattern on the flavonoid skeleton modulate the antioxidant profile. Our findings show that I. viscosa leaves may be a natural source of antioxidants and once again the role of flavonoids health benefits is more strongly endorsed.

Divergent Sepsis Pathophysiology in Older Adults

Significance: Both incidence and mortality rates of sepsis significantly increase with advanced age, and the majority of sepsis patients are late middle-aged or older. With the proportion of older adults rapidly increasing in developed countries, age-dependent sepsis vulnerability is an urgent medical issue. Due to an increasing life expectancy, postsepsis complications and health care costs are expected to increase as well. Recent Advances: Older patients suffer from higher sepsis incidence and mortality rates, likely resulting from frequent comorbidities, increased coagulation, dysgylcemia, and altered immune responses. Critical Issues: Despite a large number of ongoing clinical and basic research studies, there is currently no effective therapeutic strategy targeting older patients with severe sepsis. The disparity between clinical and basic studies is a problem, and this is largely due to the use of animal models lacking clinical relevance. Although the majority of sepsis cases occur in older adults, most laboratory animals used for sepsis research are very young. Further, despite the wide use of combination fluid and antibiotic treatment in intensive care unit (ICU) patients, most animal research does not include such treatment. Future Directions: Because sepsis is a systemic disease with multiple organ dysfunction, combined therapy approaches, not those targeting single pathways or single organs, are essential. As for preclinical research, it is critical to confirm new findings using aged animal models with clinically relevant ICU-like medical treatments. Antioxid. Redox Signal. 35, 1358-1375.

The Therapeutic Value of Hydralazine in Reducing Inflammatory Response, Oxidative Stress, and Mortality in Animal Sepsis: Involvement of the PI3K/AKT Pathway

ABSTRACT

Sepsis is an amplified systemic immune-inflammatory response produced by a microorganism, which involves activation of inflammatory cytokine signaling pathways and oxidative stress. A variety of studies have shown that hydralazine (HDZ) has potent antioxidant and anti-inflammatory proprieties. Therefore, we hypothesize that HDZ can improve the clinical outcome of sepsis. Thus, this work aimed to evaluate therapeutic value of HDZ in reducing inflammatory response, oxidative stress, and mortality in animal sepsis, and to investigate its possible mechanism of action. Sepsis was induced by the cecal ligation and puncture (CLP) method in Wistar rats. After surgery, the animals were randomly divided into three groups: sham, sepsis, and sepsis + HDZ (1 mg/kg, s.c.). All groups were monitored for 48 h to assess survival rate, and clinical, hemodynamic, biochemical, and cellular parameters. After euthanasia, blood, spleen, liver, and kidneys were collected for analysis. Blood serum cytokines, tissue myeloperoxidase (MPO) activity, and oxidative stress parameters were assessed. Involvement of the PI3K/Akt pathway was also investigated. Sepsis was successfully induced by the CLP technique. HDZ treatment increased the survival rate (from 50% to 90%), improved glycemia control, reduced the clinical severity sepsis and mean arterial pressure; and prevented increased MPO activity, TNF-α, IL-1β, IL-10 levels, and oxidative damage markers. Additionally, HDZ significantly prevented the increase of Akt activation in the liver and kidney. HDZ largely mitigated the effects of sepsis by suppressing inflammatory and antioxidant responses via the PI3K/Akt pathway. These findings provide evidence that HDZ can be a new therapeutic alternative for treating sepsis.

Neutrophil extracellular traps and organ dysfunction in sepsis

Sepsis is a clinical syndrome resulting from infection followed by inflammation and is one of the significant causes of mortality worldwide. The underlying reason is the host's uncontrolled inflammatory response due to an infection led to multiple organ dysfunction/failure. Neutrophils, an innate immune cell, are forerunners to reach the site of infection/inflammation for clearing the infection and resolute the inflammation during sepsis. A relatively new neutrophil effector function, neutrophil extracellular traps (NETs), have been demonstrated to kill the pathogens by releasing DNA decorated with histone and granular proteins. A growing number of pieces of shreds of evidence suggest that unregulated incidence of NETs have a significant influence on the pathogenesis of sepsis-induced multiple organ damage, including arterial hypotension, hypoxemia, coagulopathy, renal, neurological, and hepatic dysfunction. Thus, excessive production and improper resolution of NETs are of significant therapeutic value in combating sepsis-induced multiple organ failure. The purpose of this review is intended to highlight the role of NETs in sepsis-induced organ failure. Furthermore, the current status of therapeutic strategies to intersect the harmful effects of NETs to restore organ functions is discussed.

Aprepitant: an antiemetic drug, contributes to the prevention of acute lung injury with its anti-inflammatory and antioxidant properties

OBJECTIVES

We investigated, the effects of aprepitant (APRE) on the lung tissues of rats with an experimental polymicrobial sepsis model (CLP: cecal ligation and puncture) biochemically, molecularly and histopathologically.

METHODS

A total of 40 rats were divided into 5 groups with 8 animals in each group. Group 1 (SHAM), control group; Group 2 (CLP), cecal ligation and puncture; Group 3 (CLP + APRE10), rats were administered CLP + 10 mg/kg aprepitant; Group 4 (CLP + APRE20), rats were administered CLP + 20 mg/kg aprepitant; and Group 5 (CLP + APRE40), rats were administered CLP + 40 mg/kg aprepitant. A polymicrobial sepsis model was induced with CLP. After 16 h, lung tissues were taken for examination. Tumour necrosis factor α (TNF-α) and nuclear factor-kappa b (NFK-b) messenger ribonucleic acid (mRNA) expressions were analysed by real-time PCR (RT-PCR), biochemically antioxidant parameters such as superoxide dismutase (SOD) and glutathione (GSH) and oxidant parameters such as malondialdehyde (MDA) and lung damage histopathologically.

KEY FINDINGS AND CONCLUSIONS

The GSH level and SOD activity increased while the MDA level and the expressions of TNF-α and NFK-b were reduced in the groups treated with APRE, especially in the CLP + APRE40 group. The histopathology results supported the molecular and biochemical results.

Albumin Oxidation Status in Sepsis Patients Treated With Albumin or Crystalloids

Inflammation and oxidative stress characterize sepsis and determine its severity. In this study, we investigated the relationship between albumin oxidation and sepsis severity in a selected cohort of patients from the Albumin Italian Outcome Study (ALBIOS). A retrospective analysis was conducted on the oxidation forms of human albumin [human mercapto-albumin (HMA), human non-mercapto-albumin form 1 (HNA1) and human non-mercapto-albumin form 2 (HNA2)] in 60 patients with severe sepsis or septic shock and 21 healthy controls. The sepsis patients were randomized (1:1) to treatment with 20% albumin and crystalloid solution or crystalloid solution alone. The albumin oxidation forms were measured at day 1 and day 7. To assess the albumin oxidation forms as a function of oxidative stress, the 60 sepsis patients, regardless of the treatment, were grouped based on baseline sequential organ failure assessment (SOFA) score as surrogate marker of oxidative stress. At day 1, septic patients had significantly lower levels of HMA and higher levels of HNA1 and HNA2 than healthy controls. HMA and HNA1 concentrations were similar in patients treated with albumin or crystalloids at day 1, while HNA2 concentration was significantly greater in albumin-treated patients (p < 0.001). On day 7, HMA was significantly higher in albumin-treated patients, while HNA2 significantly increased only in the crystalloids-treated group, reaching values comparable with the albumin group. When pooling the septic patients regardless of treatment, albumin oxidation was similar across all SOFA groups at day 1, but at day 7 HMA was lower at higher SOFA scores. Mortality rate was independently associated with albumin oxidation levels measured at day 7 (HMA log-rank = 0.027 and HNA2 log-rank = 0.002), irrespective of treatment group. In adjusted regression analyses for 90-day mortality, this effect remained significant for HMA and HNA2. Our data suggest that the oxidation status of albumin is modified according to the time of exposure to oxidative stress (differences between day 1 and day 7). After 7 days of treatment, lower SOFA scores correlate with higher albumin antioxidant capacity. The trend toward a positive effect of albumin treatment, while not statistically significant, warrants further investigation.

Hyperbaric oxygen treatment impacts oxidative stress markers in patients with necrotizing soft-tissue infection

Necrotizing soft-tissue infection (NSTI) is a rare, severe, and fast-progressing bacterial infection associated with a high risk of developing sepsis or septic shock. Increasing evidence indicates that oxidative stress is crucial in the development and progression of sepsis, but its role in NSTI specifically has not been investigated. Some patients with NSTI receive hyperbaric oxygen (HBO₂) treatment as the restoration of oxidative stress balance is considered an important mechanism of action, which HBO₂ facilitates. However, a gap in knowledge exists regarding the effect of HBO₂ treatment on oxidative stress in patients with NSTI. In the present observational study, we aimed to investigate HBO₂ treatment effects on known markers of oxidative stress in patients with NSTI. We measured plasma myeloperoxidase (MPO), superoxide dismutase (SOD), heme oxygenase-1 (HO-1) and nitrite+nitrate in 80 patients with NSTI immediately before and after their first HBO₂ treatment, and on the following day. We found that HBO₂ treatment was associated with a significant increase in MPO and SOD by a median of 3.4 and 8.8 ng/mL, respectively. Moreover, we observed an HBO₂ treatment-associated increase in HO-1 in patients presenting with septic shock (n=39) by a median of 301.3 pg/mL. All markers were significantly higher in patients presenting with septic shock compared to patients without shock, and all markers correlated with disease severity. High baseline SOD was associated with 90-day mortality. In conclusion, HBO₂ treatment was associated with an increase in MPO and SOD in patients with NSTI, and oxidative stress was more pronounced in patients with septic shock.

Catalpol Inhibits Macrophage Polarization and Prevents Postmenopausal Atherosclerosis Through Regulating Estrogen Receptor Alpha

Lacking estrogen increases the risk of atherosclerosis (AS) in postmenopausal women. Inflammation plays a vital role in the pathological process of AS, and macrophages are closely related to inflammation. Catalpol is an iridoid glucoside extracted from the fresh roots of the traditional Chinese herb Rehmanniae radix preparata. In this study, we aimed to evaluate the effects of catalpol on macrophage polarization and postmenopausal AS. In addition, we investigated whether the mechanism of catalpol was dependent on regulating the expression of estrogen receptors (ERs). In vitro, lipopolysaccharides (LPS) and interferon-γ (IFN-γ) were applied to induce M1 macrophage polarization. In vivo, the ApoE-/- mice were fed with a high-fat diet to induce AS, and ovariectomy was operated to mimic the estrogen cessation. We demonstrated catalpol inhibited M1 macrophage polarization induced by LPS and INF-γ, and eliminated lipid accumulation in postmenopausal AS mice. Catalpol not only suppressed the inflammatory response but also reduced the level of oxidative stress. Then, ERs (ERα and ERβ) inhibitors and ERα siRNA were also applied in confirming that the protective effect of catalpol was mediated by ERα, rather than ERβ. In conclusion, catalpol significantly inhibited macrophage polarization and prevented postmenopausal AS by increasing ERα expression.

Protective Effects of Idebenone against Sepsis Induced Acute Lung Damage

BACKGROUND/AIMS

Sepsis is an uncontrolled systemic infection, withcomplex pathophysiology that may result in acute lung organ damage and cause multiple organ failure. Although much research has been conducted to illuminate sepsis's complex pathophysiology, sepsis treatment protocols are limited, and sepsis remains an important cause of mortality andmorbidity in intensive care units.Various studies have shown that idebenone (IDE) possesses strong antioxidant properties, which inhibit lipid peroxidation and protect cells from oxidative damage. The present study aimed to evaluate the protective effects of IDE against lung injury in a cecal ligation and puncture (CLP)-induced sepsis rat model.

METHODS

Male albino Wistar rats were used. The animals were divided into a healthy control (no treatment), CLP, IDE control (200 mg/kg), and CLP + IDE subgroups (50 mg/kg, 100 mg/kg, and 200 mg/kg), with nine rats in each group.IDE was administered 1 h after CLP induction.To evaluate the protective effects of IDE, lung tissues were collected 16 h after sepsis for biochemical, immunohistochemical staining, and histopathological examination.

RESULTS

IDE significantly ameliorated sepsis-induced disturbances in oxidative stress-related factors, with its effects increasing in accordance with the dose.IDE also abolished histopathological changes in lung tissues associated with CLP.Furthermore, interleukin 1 beta (IL-1β)and tumor necrosis factor-alpha (TNF-α) immunopositivity markedly decreased in the septic rats following IDE treatment.

CONCLUSIONS

IDE largely mitigated the inflammatory response in sepsis-induced lung injury by decreasing free radicals and preventing lipid peroxidation. The results suggest that IDE may represent a potential novel therapeutic drug for sepsis treatment.

Functional role of iNOS-Rac2 interaction in neutrophil extracellular traps (NETs) induced cytotoxicity in sepsis

BACKGROUND

Recent reports from this lab have demonstrated a higher incidence of NETs, nitrosative, as well as oxidative stress, and have a direct correlation with the severity of sepsis and organ damage. However, the mechanistic perspective of NETs induced organ damage has not been understood at the cellular and molecular level. Interaction of inducible nitric oxide synthase (iNOS) with Rac2 in regulating reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation and its implications in microbial killing has been reported. This study was, therefore, undertaken in neutrophils of sepsis patients to investigate the functional importance of iNOS-Rac2 interaction in ROS/ RNS, peroxynitrite generation, NETs generation, and NETs mediated cell death.

METHODS

The study was conducted on 100 patients with sepsis and 50 healthy volunteers. Interaction between iNOS and Rac2 was performed using co-immunoprecipitation and co-immunolabeling assay. Free radicals involving ROS and RNS were evaluated using cytochrome c reduction assay. NETs formation was evaluated by fluorescence microscopy. The cytotoxic effect of NETs was assessed on lung carcinoma cell line (A549) using colorimetric Alamar blue assay.

RESULTS

Enhanced interaction between iNOS and Rac2 was found in sepsis neutrophils in comparison with control. This was accompanied by an increased level of superoxide (O2.-), nitric oxide (NO), and peroxynitrite (ONOO-) which were decreased in the presence of NAC, DPI, and 1400 W, signifying the role of iNOS-Rac2 interaction. Enhanced NETs release from activated sepsis neutrophils were abrogated in the presence of DPI. NETs from sepsis neutrophils exert a cytotoxic effect on lung epithelial cells (A549) in a concentration-dependent manner.

CONCLUSION

Our findings exhibit the functional role of iNOS-Rac2 interaction in ROS/RNS, peroxynitrite generation, NETs generation, and NETs mediated cell death.

Evaluating the Possibility of Translating Technological Advances in Non-Invasive Continuous Lactate Monitoring into Critical Care

Lactate is widely measured in critically ill patients as a robust indicator of patient deterioration and response to treatment. Plasma concentrations represent a balance between lactate production and clearance. Analysis has typically been performed with the aim of detecting tissue hypoxia. However, there is a diverse range of processes unrelated to increased anaerobic metabolism that result in the accumulation of lactate, complicating clinical interpretation. Further, lactate levels can change rapidly over short spaces of time, and even subtle changes can reflect a profound change in the patient's condition. Hence, there is a significant need for frequent lactate monitoring in critical care. Lactate monitoring is commonplace in sports performance monitoring, given the elevation of lactate during anaerobic exercise. The desire to continuously monitor lactate in athletes has led to the development of various technological approaches for non-invasive, continuous lactate measurements. This review aims firstly to reflect on the potential benefits of non-invasive continuous monitoring technology within the critical care setting. Secondly, we review the current devices used to measure lactate non-invasively outside of this setting and consider the challenges that must be overcome to allow for the translation of this technology into intensive care medicine. This review will be of interest to those developing continuous monitoring sensors, opening up a new field of research.

Short-term Effects of Metformin on Cardiac and Peripheral Blood Cells Following Cecal Ligation and Puncture-induced Sepsis

AIM OF THE STUDY

Sepsis has well-documented inflammatory effects on cardiovascular and blood cells. This study is designed to investigate potential anti-inflammatory effects of metformin on cardiac and blood cells 12 and 24 h following cecal ligation and puncture (CLP)-induced sepsis.

METHODS

For the purpose of this study, 36 male Wistar rats were divided into six groups: two groups underwent CLP, two groups underwent CLP and received metformin, and two groups only received sham operations. 12 h later, 18 rats (half of rats in each of the three aforementioned groups) were sacrificed and cardiac and blood cells were harvested. Subsequently, 12 h later, the rest of the rats were euthanatized. In all harvested blood and cardiac cells, oxidative stress indicators, antioxidant properties, count of blood cells, neutrophil infiltration, percentage of weight loss and pathological assessment were conducted.

RESULTS

In our experiment, metformin elevated antioxidant levels, improved function of blood cells and percentage of weight loss. Moreover, in the groups which received metformin, oxidative stress and neutrophil infiltration markers were decreased significantly. Moreover, pathological investigations of cardiac cell injury were reduced in the metformin group.

CONCLUSIONS

Our findings suggest that in CLP induced sepsis model, metformin can improve the function of blood and cardiac cells through alleviating inflammation, improvement of anti-inflammation properties, and enhancement of blood profile, and all these effects are more pronounced after 24 h in comparison with 12 h after induction of sepsis.

P2X7 receptor deletion attenuates oxidative stress and liver damage in sepsis

Sepsis is a severe disease characterized by an uncontrolled systemic inflammation and consequent organ dysfunction generated in response to an infection. Extracellular ATP acting through the P2X7 receptor induces the maturation and release of pro-inflammatory cytokines (i.e., IL-1β) and the production of reactive nitrogen and oxygen species that lead to oxidative tissue damage. Here, we investigated the role of the P2X7 receptor in inflammation, oxidative stress, and liver injury in sepsis. Sepsis was induced by cecal ligation and puncture (CLP) in wild-type (WT) and P2X7 knockout (P2X7-/-) mice. The oxidative stress in the liver of septic mice was assessed by 2',7'-dichlorofluorescein oxidation reaction (DCF), thiobarbituric acid-reactive substances (TBARS), and nitrite levels dosage. The status of the endogenous defense system was evaluated through catalase (CAT) and superoxide dismutase (SOD) activities. The inflammation was assessed histologically and by determining the expression of inflammatory cytokines and chemokines by RT-qPCR. We observed an increase in the reactive species and lipid peroxidation in the liver of septic WT mice, but not in the liver from P2X7-/- animals. We found an imbalance SOD/CAT ratio, also only WT septic animals. The number of inflammatory cells and the gene expression of IL-1 β, IL-6, TNF-α, IL-10, CXCL1, and CXCL2 were higher in the liver of WT septic mice in comparison to P2X7-/- septic animals. In summary, our results suggest that the P2X7 receptor might be a therapeutic target to limit oxidative stress damage and liver injury during sepsis.

Correlation of Redox Status with Procalcitonin and C-reactive Protein in Septic Patients

Based on the role of oxidative stress in the pathophysiological mechanisms of sepsis and the importance of PCT as a clinically applicable biomarker for early detection of inflammatory response initiation, we aimed this study at examining the correlation between PCT levels and oxidative stress parameters (prooxidants and antioxidants) in patients with sepsis. This study was designed as a case-series prospective clinical study which involved 103 critically ill patients and 17 healthy participants with diagnosis of sepsis/septic shock (over 18 years of age, both gender) admitted to the Intensive Care Unit (ICU) of Valjevo General Hospital in Serbia. All subjects were divided into patients who were operated on/underwent surgery before sampling and have sepsis (n = 24), patients who were operated on/underwent surgery before sampling and have septic shock (n = 25), patients who were not operated on/did not undergo surgery before sampling and have sepsis (n = 26), patients who were not operated on/did not undergo surgery before sampling and have septic shock (n = 28), and participants who are healthy (n = 17). PCT has confirmed a positive correlation with prooxidants and type of critical illness, and performing surgical intervention diminished oxidative stress in patients with septic shock. Prognosis in critically ill patients was strongly associated with PCT levels but not with nonspecifically C-reactive protein.

Lipidomic profile and candidate biomarkers in septic patients

Sepsis is a severe disease with a high mortality rate. Identification and treatment in the initial hours of the disease improve outcomes. Some biomarkers like procalcitonin and C-reactive protein are used for diagnosis and to access sepsis prognosis and they can help in clinical decision-making, but none has sufficient specificity or sensitivity to be routinely employed in clinical practice. This review seeks to evaluate lipid metabolism alterations in patients with sepsis and the possibility of using the respective metabolites as biomarkers of the disease. A search of the main electronic biomedical databases was conducted for the 20-year period ending in February 2020, focused on primary research articles on biomarkers in sepsis. The keywords included sepsis, septic shock, biomarker, metabolomic, lipidomic and lysophosphatidylcoline.

. It concludes that altered lipid profiles, along with the progress of the disease should provide new insights, enabling a better understanding of the pathogenic mechanisms and making it possible to design new early diagnosis and therapeutic procedures for sepsis.

Presepsin Levels in Experimental Sepsis and Massive Bowel Resection Models in Rats

BACKGROUND/AIM

Presepsin is a useful biomarker for diagnosing sepsis. This study aimed to investigate the relationship between oxidative stress and presepsin levels in animal models.

MATERIALS AND METHODS

Sprague-Dawley rats were used for cecal ligation and puncture (CLP) and to generate massive bowel resection (MBR) models. Trunk blood was collected for analysis of presepsin. Liver and intestinal tissue samples were taken to determine oxidative stress parameters.

RESULTS

Presepsin levels in MBR and CLP sepsis models were higher than those in control groups. Reactive oxygen and nitrogen species (RONS) and malondialdehyde levels were increased in the liver and small intestine of rats in both models, whereas glutathione levels were decreased.

CONCLUSION

Presepsin levels and RONS may be released by the same mechanism which is closely associated with the progression of sepsis and inflammation in both CLP and MBR models.

Exploring the Biomarkers of Sepsis-Associated Encephalopathy (SAE): Metabolomics Evidence from Gas Chromatography-Mass Spectrometry

Background

Sepsis-associated encephalopathy (SAE) is a transient and reversible brain dysfunction, that occurs when the source of sepsis is located outside of the central nervous system; SAE affects nearly 30% of septic patients at admission and is a risk factor for mortality. In our study, we sought to determine whether metabolite changes in plasma could be a potential biomarker for the early diagnosis and/or the prediction of the prognosis of sepsis.

Method

A total of 31 SAE patients and 28 healthy controls matched by age, gender, and body mass index (BMI) participated in our study. SAE patients were divided into four groups according to the Glasgow Coma Score (GCS). Plasma samples were collected and used to detect metabolism changes by gas chromatography-mass spectrometry (GC-MS). Analysis of variance was used to determine which metabolites significantly differed between the control and SAE groups.

Results

We identified a total of 63 metabolites that showed significant differences among the SAE and control groups. In particular, the 4 common metabolites in the four groups were 4-hydroxyphenylacetic acid; carbostyril, 3-ethyl-4,7-dimethoxy (35.8%); malic acid peak 1; and oxalic acid. The concentration of 4-hydroxyphenylacetic acid in sepsis patients decreased with a decrease of the GCS.

Conclusions

According to recent research on SAE, metabolic disturbances in tissue and cells may be the main pathophysiology of this condition. In our study, we found a correlation between the concentration of 4-hydroxyphenylacetic acid and the severity of consciousness disorders. We suggest that 4-hydroxyphenylacetic acid may be a potential biomarker for SAE and useful in predicting patient prognosis.

The Pathogenesis of Sepsis and Potential Therapeutic Targets

Sepsis is defined as “a life-threatening organ dysfunction caused by a host’s dysfunctional response to infection”. Although the treatment of sepsis has developed rapidly in the past few years, sepsis incidence and mortality in clinical treatment is still climbing. Moreover, because of the diverse manifestations of sepsis, clinicians continue to face severe challenges in the diagnosis, treatment, and management of patients with sepsis. Here, we review the recent development in our understanding regarding the cellular pathogenesis and the target of clinical diagnosis of sepsis, with the goal of enhancing the current understanding of sepsis. The present state of research on targeted therapeutic drugs is also elaborated upon to provide information for the treatment of sepsis.

Prediction of presepsin concentrations through commensurate decline in kidney function in the elderly

BACKGROUND

Presepsin is a useful biomarker to diagnose sepsis. However, the correlation between plasma presepsin concentrations and kidney function in the elderly with chronic kidney disease (CKD) remains to be elucidated. We determined whether plasma presepsin concentrations were influenced by kidney function decline in the elderly.

METHODS

One hundred seventy outpatients with CKD aged ≥65 y were enrolled. Plasma presepsin concentrations were measured using immunoassay analysis. The relationship between plasma presepsin concentration and kidney function was assessed.

RESULTS

The median age of patients of this cohort was 778 (72-85) y and the mean estimated glomerular filtration rate was 51.8 ± 28.1 ml/min/1.73 m². Plasma presepsin concentrations in those with CKD G4-G5 (362 pg/ml [273-553]) were significantly higher than in those with CKD G1-G2 (111 pg/ml [91-113]) and CKD G3 (145 pg/ml [124-205]) (p < 0.001, p < 0.001, respectively). A high correlation between plasma presepsin concentrations and kidney function was observed (R² = 0.733, p < 0.001). Even after adjusting for confounders, plasma presepsin concentrations were independently associated with kidney function.

CONCLUSIONS

Increases in plasma presepsin concentrations were exponentially correlated to kidney function decline in the elderly with CKD.