Evaluation of oxidative stress and inflammation in long term Brucella melitensis infection

Neurobrucellosis (Brucella ceti) in striped dolphins (Stenella coeruleoalba): Immunohistochemical studies on immune response and neuroinflammation

Neurobrucellosis is a shared condition of cetaceans and humans. However, the pathogenesis and immune response in cetacean neurobrucellosis has not been extensively studied. In this multicentric investigation, 21 striped dolphin (Stenella coeruleoalba) neurobrucellosis (Brucella ceti) cases diagnosed over a 10-year period (2012-2022) were retrospectively evaluated. For each case, morphological changes were assessed by evaluating 21 histological parameters. Furthermore, the immunohistochemical expression of Brucella antigen, glial fibrillary acid protein (GFAP), and a selection of inflammatory cell (IBA-1, CD3, and CD20) and cytokine (tumor necrosis factor-alpha [TNF-α], interferon-gamma [IFN-γ], interleukin [IL]-1β, IL-2, and IL-6) markers were investigated. Inflammation of the leptomeninges, ependyma, and/or choroid plexus was lymphohistiocytic, containing macrophages/microglia (IBA-1+), T-cells (CD3+), and B-cells (CD20+) in equal proportion. B-cells occasionally formed tertiary follicles. GFAP expression showed astrocytosis in most cases. Expression of TNF-α, IFN-γ, and IL-2 indicated an intense proinflammatory response, stimulating both macrophages and T-cells. Our results showed that the inflammation and neuroinflammation in neurobrucellosis of striped dolphins mimic human neurobrucellosis and in vitro and in vivo studies in laboratory animals. Cetacean disease surveillance can be exploited to expand the knowledge of the pathogenesis and immunology of infectious diseases, particularly brucellosis, under a One Health approach.

Investigation of serum ischemic-modified albumin, galectin-3, paraoxonase-1, and myeloperoxidase activity levels in patients with acute brucellosis

OBJECTIVES

Infection remains current as an important discussion topic in the etiological factors of atherosclerosis. Ischemic-modified albumin (IMA), galectin-3 (gal-3), paraoxonase-1 (PON-1), and myeloperoxidase (MPO) are biomolecules that play an important role in the pathogenesis of atherosclerosis. Our aim is to investigate serum IMA, gal-3, PON-1, and MPO activity in acute brucellosis infection.

MATERIALS AND METHODS

Forty patients with acute brucellosis and 40 healthy individuals were included in the study. Serum IMA, gal-3, PON-1, and MPO activity were analyzed by the ELISA method.

RESULTS

In acute brucellosis infection, serum gal-3, IMA, and MPO activities were found to be significantly increased compared to the control group, and PON-1 activity was found to be significantly decreased compared to the control group (p < 0.001). There was a positive correlation between serum IMA, and MPO activity (r = 0.707 p = 0.000) and a negative correlation (r = -0.943, p = 0.000) between PON-1 activity. There was a positive correlation between serum gal-3 and MPO activity (r = 0.683, p = 0.000) and IMA level (r = 0.927, p = 0.000) and a negative correlation between PON-1 activity (r = -0.951, p = 0.000).Conclusion, it was found that serum gal-3, IMA levels and MPO activity increased, while PON-1 activity decreased. These results showed that the oxidant-anti-oxidant balance is impaired in acute brucellosis infection. In addition, these results indicate that brucella infection may be increase the risk of atherosclerosis. Further studies are needed to support our findings.

The Effects of Probiotics Supplementation on Clinical Status and Biomarkers of Oxidative Damage and Inflammation in Children with Brucellosis: A Randomized, Double-Blind, and Placebo-Controlled Trial

Background

Increased levels of inflammatory cytokines and oxidative damage may play crucial roles in the pathogenesis of brucellosis. The purpose of this trial was to evaluate the impact of probiotics administration on clinical status and biomarkers of oxidative damage and inflammation in pediatric patients diagnosed with brucellosis.

Methods

This randomized, double-blind, and placebo-controlled trial was performed by recruiting 40 patients, 8–15 years of age, who had been diagnosed with brucellosis. Study participants were randomly allocated into two groups to receive either probiotics supplement or placebo (n = 20 each group) for 8 weeks. Blood samples were collected at the onset and after 8 weeks of intervention to quantify biochemical parameters. Clinical status was examined by a pediatric infectious disease specialist.

Results

Following 8-week intervention, probiotics supplementation substantially improved total antioxidant capacity (P < 0.001) and malondialdehyde (P=0.002). Furthermore, the difference between probiotics group and placebo group for the duration of fever (P=0.02) and musculoskeletal pain (P=0.001) was statistically significant, though probiotics administration had no significant effects on high-sensitivity C-reactive protein, total glutathione, and other clinical outcomes compared with placebo.

Conclusion

Overall, probiotics intake had beneficial impact on clinical status and body antioxidative defense system in pediatric patients with brucellosis.

Evaluation of antioxidants, nitrosative, and oxidative stress before & after acute brucellosis treatment in North of Iran

BACKGROUND

In vivo studies of antioxidants, nitrosative, and oxidative processes in Brucella infection have not been comprehensive. This research looked at these critical concerns before and after treating individuals with acute brucellosis.

METHODS

A total of 50 individuals with acute brucellosis were studied before and after treatment in Babol, Iran. Superoxide dismutase (SOD) activity, plasma total antioxidant capacity (TAC), catalase (CAT) activity, protein carbonyl, oxidative stress markers like malondialdehyde (MDA), and nitrosative stress markers such as nitrite oxide metabolites (NO3, NO2) were all assessed.

RESULTS

The individuals were 44.15 ± 13.5 years old on average. Before therapy, protein carbonyl and plasma MDA were 0.887 ± 0.12 and 0.725 ± 0.33, respectively, and after treatment, they were 0.697 ± 0.17 and 0.467 ± 0.48 (p < 0.05). After treatment, the average TAC level was greater (870.1 ± 88.64 mol/l vs. 670.13 ± 133.96 mol/l) (p < 0.001). Before and after therapy, CAT activity was significantly different (8.53 ± 2.70 vs. 6.94 ± 2.84, p < 0.001). In addition, SOD activity was 41.79 ± 9.79 before treatment and 28.95 ± 8.11 after treatment (p < 0.001). The difference in plasma nitrite oxide levels before and after therapy was substantial (50.89 ± 17.74 vs. 28.68 ± 15.97, p < 0.001).

CONCLUSION

The findings revealed that in acute brucellosis, nitrosative and oxidative stress, as well as antioxidant depletion, were all elevated. The addition of appropriate natural antioxidants to therapy regimens may improve their effectiveness.

Mapping of oxidative stress in immune response induced by polymer gel based Brucella melitensis vaccine in mice

Brucella melitensis is an obligate intracellular parasite causing worldwide zoonoses. It has been implicated that oxidative stress induced due to bacterial invasion lead to the niche of Brucella in organs like spleen and lymph nodes. The present study was aimed at evaluating the erythrocytic and tissue specific oxidative stress responses induced by intranasal inoculation of killed Brucella whole cell protein antigen in conjunction with a polymer gel adjuvant for offering protection against live virulent Brucella. The results clearly implicate that both the glutathione mediated nonenzymic antioxidant defense system and catalase play a critical role in intracellular antioxidant defense in vaccinated animals along with maintaining an excellent milieu for inducing an active immune potential. At the same time, the antioxidant defenses in all the vital tissues, viz. liver, kidney, lung and spleen of vaccinated mice were almost at par with the adjuvant inoculated animals. Thus, it may be said that intranasal immunization with polymer gel based Brucella vaccine induces an oxidative stress with negligible signs of inflammatory pathophysiology in all the vital organs and supports the development of significant level of immunogenicity against Brucella challenge.

Impaired Thiol-Disulfide Balance in Acute Brucellosis

The objective of this study was to examine a novel profile: thiol-disulfide homeostasis in acute brucellosis. The study included 90 patients with acute brucellosis, and 27 healthy controls. Thiol-disulfide profile tests were analyzed by a recently developed method, and ceruloplasmin levels were determined. Native thiol levels were 256.72 ± 48.20 μmol/L in the acute brucellosis group and 461.13 ± 45.37 μmol/L in the healthy group, and total thiol levels were 298.58 ± 51.78 μmol/L in the acute brucellosis group and 504.83 ± 51.05 μmol/L in the healthy group (p < 0.001, for both). The disulfide/native thiol ratios and disulfide/total thiol ratios were significantly higher, and native thiol/total thiol ratios were significantly lower in patients with acute brucellosis than in the healthy controls (p < 0.001, for all ratios). There were either positive or negative relationships between ceruloplasmin levels and thiol-disulfide parameters. The thiol-disulfide homeostasis was impaired in acute brucellosis. The strong associations between thiol-disulfide parameters and a positive acute-phase reactant reflected the disruption of the balance between the antioxidant and oxidant systems. Since thiol groups act as anti-inflammatory mediators, the alteration in the thiol-disulfide homeostasis may be involved in brucellosis.

TNF-α -238, -308, -863 polymorphisms, and brucellosis infection

BACKGROUND

Brucella abortus is an intracellular bacterium that affects humans and domestic animals. Tumor necrosis factor-alpha (TNF-α) has been shown as a key player in the induction of cell-mediated resistance against Brucella infection. We aimed to evaluate the possible influence of the TNF-α promoter polymorphisms (-308 G/A, -238 G/A, and -863 C/A) on the susceptibility of human brucellosis.

METHODOLOGY

A total of 153 patients with active brucellosis and 128 healthy individuals were recruited. All subjects were genotyped for the polymorphisms in the TNF-α gene by Allele-Specific polymerase chain reaction analysis.

RESULTS

Our results showed that the TNF-α -308 GG genotype was significantly more frequently present in controls than in brucellosis patients (91% vs. 75%), thus was a protective factor against developing brucellosis (OR=0.313, p=0.001). In contrast, the -308 GA genotype (OR=3.026, p=0.002) and minor allele (A) (OR=3.058, p=0.001) as well as AAG haplotype (OR=4.014, p=0.001) conferred an increased risk of brucellosis. However, the -238 G/A and -863 C/A polymorphisms were not associated with the risk of brucellosis at both allelic and genotypic levels (p>0.05).

CONCLUSION

Our study revealed that the TNF-α -308 A allele or GA heterozygosity or AAG haplotype were associated with an increased risk of brucellosis in our population.

Serum paraoxonase activity, total thiols levels, and oxidative status in patients with acute brucellosis

It is well known that paraoxonase-1 (PON1) activity may decrease during the course of infection and inflammation. The aim of this study was to investigate serum PON1 activity, oxidative status, and thiols levels in patients with acute brucellosis. In addition, we investigated the PON1 phenotype in patients with acute brucellosis. Thirty patients with acute brucellosis and 35 healthy controls were enrolled. Serum paraoxonase and arylesterase activities, thiols levels, lipid hydroperoxide levels, total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined. Serum basal and salt-stimulated paraoxonase-arylesterase activities, TAC levels and thiols levels were significantly lower in patients with acute brucellosis than controls (for all, p < 0.05), while LOOH levels, TOS levels, and OSI values were significantly higher (for all, p < 0.05). We concluded that oxidative stress is increased, while serum PON1 activity is decreased in patients with acute brucellosis. These results indicate that lower PON1 activity is associated with oxidant-antioxidant imbalance.

Serum myeloperoxidase activity and oxidative stress in patients with acute brucellosis

OBJECTIVES

The role of infection in the pathogenesis of atherosclerosis has been increasingly discussed. Previous studies have suggested that increased myeloperoxidase activity plays an important role in the pathogenesis of atherosclerosis. The aim of this study was to investigate the serum myeloperoxidase activity and catalase activity along with lipid hydroperoxide (LOOH) levels in patients with acute brucellosis.

DESIGN AND METHODS

Thirty-two patients with brucellosis and 33 healthy controls were enrolled. Serum myeloperoxidase activity, catalase activity and LOOH levels were determined.

RESULTS

Serum myeloperoxidase activity and LOOH levels were significantly higher in patients with brucellosis than controls (p<0.05, p<0.001), while catalase activity were significantly lower (p<0.001). LOOH levels were found to be significantly positively correlated with MPO activity (r=0.297, p=0.016) in patients.

CONCLUSIONS

These results indicate that increased myeloperoxidase activity and decreased catalase activity is associated with increased oxidative stress, which may have a role in atherosclerotic processes in brucellosis patients.

Evaluation of oxidative status in patients with Fasciola hepatica infection

BACKGROUND

F. hepatica infection is rare and mostly subclinical. Migration of juvenile forms of F. hepatica into the host's liver is accompanied by an inflammatory reaction followed by fibrosis and cirrhosis.

OBJECTIVE

The aim of this study was to evaluate oxidative status by using a novel automated method in patients with Fasciola hepatica.

METHODS

Twenty two patients with a diagnosis of F. hepatica and 26 healthy volunteers were enrolled in the study. Their Total antioxidant capacity status (TAC), total oxidant status (TOS) and catalase were measured in them and oxidative stress index (OSI) was calculated. These measurements were also taken for the control group and the values were compared.

RESULTS

Plasma levels of total TOS and OSI were significantly increased in patients as compared with healthy controls (P<0.001, P<0.001, P=0.001, P=0.008) respectively. In contrast, TAC level was significantly lower in patients as compared with controls (p<0.05). There was no significant difference between the catalase results of the two groups (p>0.05).

CONCLUSION

Total oxidative status and OSI were increased and total antioxidative status capacity was decreased in patients with F. hepatica infection. A high oxidative stress occurs during F. hepatica infection, which may cause severe damage in both the liver.

The effects of increased cAMP content on inflammation, oxidative stress and PDE4 transcripts during Brucella melitensis infection

Cyclic AMP (cAMP) is a key intracellular second messenger which at increased levels has been shown to have anti-inflammatory and tissue-protective effects. Its concentration is determined by the activities of both adenylate cyclase (AC) and the phosphodiesterase (PDE) enzymes. The aim of this study was to compare the effects of increased cAMP and glucocorticoid dexamethasone administration on B. melitensis-induced lipid peroxidation, Brucella suppressed antioxidant enzyme activities and PDE4 transcripts in rats. Intracellular cyclic AMP level was elevated by two different approaches; activation of AC and inhibition of PDE activities. Rats were inoculated with B. melitensis for seven days then a single dose of nonselective PDE inhibitor 3-isobutyl-1-methylxanthine (IBMX), the adenylate cyclase activator forskolin and dexamethasone were administrated to each infected group, and animals were challenged for 48 h. Brucella-induced lipid peroxidation was significantly reduced by the cAMP elevating agents as well as dexamethasone administration in plasma, liver and spleen. The antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities were significantly decreased by the pathogen. Whilst suppressed GSH-Px activity was reversed by cAMP elevating agents, SOD activity was not restored. Superoxide generating enzyme xanthine oxidase activity was not altered at the end of the infection period. Brucella infection increased plasma IL-12 level and this effect was also suppressed by the cAMP elevating agents, whereas TNF-alpha, IFN-gamma and IL-10 levels were unchanged. Intracellular cAMP levels are entirely hydrolyzed by cAMP-specific PDE 4 isozymes (PDE4s) in inflammatory and immunocompetent cells. Brucella reduced mRNA transcript levels for PDE4A by 40%, though PDE4B and 4D transcriptions were being unaffected in spleen. It was concluded that B. melitensis infection decreased activity of the antioxidant defence system, induced lipid peroxidation and suppressed PDE4A transcription. Administration of cAMP elevating agents exhibited similar affect with dexamethasone on lipid peroxidation, IL-12 production and antioxidant enzyme activities in Brucella infection.