The interrelation of glutathione reductase, catalase, glutathione peroxidase, superoxide dismutase, and glucose-6-phosphate in the pathogenesis of rheumatoid arthritis

Antioxidant and anti-inflammatory potentials of Ammodaucus leucotrichus Coss. & Durieu seeds' extracts: In vitro and in vivo studies

ETHNOPHARMACOLOGICAL RELEVANCE

Ammodaucus leucotrichus Coss. & Durieu (Apiaceae) is traditionally used in southern Algeria as a remedy against a wide range of disease due to its health-promoting properties.

AIM OF THE STUDY

To investigate anti-oxidant and anti-inflammatory potentials of plant methanolic extract and its fractions in vitro and in vivo.

MATERIALS AND METHODS

Anti-radical activity was assessed in vitro using ABTS•+, superoxide anion (O2•-) and nitric oxide radical (•NO). Lipid peroxidation inhibition was also investigated in the linoleic acid system. Enzyme inhibition assay was performed against α-amylase and α-glucosidase. The anti-inflammatory effect of extracts was screened in vitro through thermal induction of human serum albumin, and in vivo on a skin acute inflammation model induced by λ-carrageenan paw injection, xylene and croton oil topical application. Analgesic effect was evaluated by acetic acid-induced writhing test.

RESULTS

The highest contents of polyphenols and flavonoids was recorded by the crude extract (77.14 ± 0.01 μg GAE/mg E and 19.59 ± 0.08 μg QE/mg E, respectively). Among the extracts, ethyl acetate extract showed a promising anti-radical activity of ABTS•+, O2•- and •NO, in addition to a remarkable inhibition activity of the tested enzymes. Meanwhile, all extracts effectively protected linoleic acid against lipid peroxidation and human serum albumin structure in thermal condition even at low concentration (0.31 mg/ml). Oral administration of 200 mg/kg of crude extract successfully inhibited acetic acid induced nociception and reduced edema formation induced by xylene and carrageenan. However, a dose-dependent manner was observed to decrease ear edema by a microscopic examination in croton oil induced acute inflammation. Nitrite and malondialdehyde levels together with catalase activity were modulated in the presence of plant-derived bioactive compounds.

CONCLUSIONS

This study showed that Ammodaucus leucotrichus is potentially rich source of anti-oxidant and anti-inflammatory bioactive compounds.

Association between secondhand smoke exposure and rheumatoid arthritis in US never-smoking adults: a cross-sectional study from NHANES

While smoking is widely acknowledged as a risk factor for rheumatoid arthritis (RA), the connection between secondhand smoke (SHS) exposure and RA in never-smoking adults remains limited and inconsistent. This study aims to explore and quantify this association using serum cotinine levels. We conducted a cross-sectional study with 14,940 adults who self-report as never smokers, using National Health and Nutrition Examination Survey data from 1999 to 2018. Based on previous literature, SHS exposure was categorized into four groups according to serum cotinine levels. Compared to individuals in the unexposed group (serum cotinine < 0.05 ng/mL), the adjusted odds ratio (OR) for RA was 1.37 (95% CI 1.14-1.64, p = 0.001) in the low exposure group (serum cotinine at 0.05 to 0.99 ng/mL) after adjusting for covariates. However, no significant association was found in the moderate exposure group (serum cotinine at 1 to 10 ng/mL) or the heavy exposure group (serum cotinine ≥ 10 ng/mL). Furthermore, we detected a non-linear, positively saturated correlation between the cotinine levels after log2 transformation and RA, with a turning point at approximately - 2.756 ng/mL (OR = 1.163, 95% CI 1.073-1.261, p = 0.0002). The stability of the results was confirmed by subgroup analysis.

The efficacy of curcumin supplementation on serum total antioxidant capacity, malondialdehyde, and disease activity in women with rheumatoid arthritis: A randomized, double-blind, placebo-controlled clinical trial

Oxidative stress plays a crucial role in the physiopathology of rheumatoid arthritis (RA), which is associated with impaired antioxidant defenses. This study aimed to investigate the effects of curcumin supplementation on serum levels of total antioxidant capacity (TAC), malondialdehyde (MDA), and disease activity in women with RA. In this clinical trial, 48 women with RA were treated with one capsule of curcumin (500 mg daily) or placebo for 8 weeks. Anthropometric measurements and fasting blood samples were collected at baseline and end of the study. Finally, we assessed the Disease Activity Score in 28 joints (DAS-28), dietary intake, and physical activity levels. While curcumin supplementation for 8 weeks significantly increased the serum levels of TAC (p < 0.05), it decreased tender joint counts, swollen joint counts, visual analog scale (VAS) for pain, and DAS-28 compared to the placebo at the end of the study (p < 0.001 for all). MDA levels significantly decreased in the curcumin group (p < 0.05). However, changes in MDA concentration were not significant between groups at the end of the trial (p = 0.145). Curcumin supplementation had a beneficial effect on increasing the serum levels of TAC and decreased DAS-28 in women with RA.

Association between oxidative balance score and rheumatoid arthritis in female: a cross-sectional study

OBJECTIVE

Although oxidative stress is a recognized factor of inflammation, the correlation between oxidative balance score (OBS), a biomarker indicating the balance of oxidation and antioxidant, and rheumatoid arthritis (RA), an immune system disease that tends to occur in women, remains unexplored. Hence, the aim of this study was to investigate the potential association between OBS and RA in women.

METHODS

Observational surveys were performed by employing information extracted from the National Health and Nutrition Examination Survey (NHANES) for the period 2007-2018. Various statistical techniques were employed to investigate the association between OBS and RA, encompassing multivariable logistic regression analysis, subgroup analyses, smooth curve fitting, and threshold effect analysis.

RESULTS

The study included 8219 female participants, including 597 patients with RA. The results showed that higher Total OBS (TOBS) significantly correlated with lower RA prevalence in the entirely modified model [odd ratio (OR) = 0.968; 95% confidence interval (CI) = 0.952 to 0.984; P = 0.0001]. Dietary OBS (DOBS) and lifestyle OBS (LOBS) also negatively correlated with RA. This association was remarkably consistent across TOBS subgroups by age, race, education level, family poverty-to-income ratio (PIR), hypertension and diabetes. Smooth curve fitting and threshold effect analysis also revealed the linear relationship between OBS and RA.

CONCLUSIONS

Overall, OBS was negatively associated with RA in female. This study suggested that an antioxidant diet and lifestyle may be promising measures to prevent RA in female.

Reactive X (where X = O, N, S, C, Cl, Br, and I) species nanomedicine

Reactive oxygen, nitrogen, sulfur, carbonyl, chlorine, bromine, and iodine species (RXS, where X = O, N, S, C, Cl, Br, and I) have important roles in various normal physiological processes and act as essential regulators of cell metabolism; their inherent biological activities govern cell signaling, immune balance, and tissue homeostasis. However, an imbalance between RXS production and consumption will induce the occurrence and development of various diseases. Due to the considerable progress of nanomedicine, a variety of nanosystems that can regulate RXS has been rationally designed and engineered for restoring RXS balance to halt the pathological processes of different diseases. The invention of radical-regulating nanomaterials creates the possibility of intriguing projects for disease treatment and promotes advances in nanomedicine. In this comprehensive review, we summarize, discuss, and highlight very-recent advances in RXS-based nanomedicine for versatile disease treatments. This review particularly focuses on the types and pathological effects of these reactive species and explores the biological effects of RXS-based nanomaterials, accompanied by a discussion and the outlook of the challenges faced and future clinical translations of RXS nanomedicines.

Metabolomic and proteomic analyses of primary Sjogren's syndrome

The pathogenesis of primary Sjogren's syndrome (pSS) has not been fully elucidated. We explored differentially expressed proteins and metabolic pathways in pSS using proteomics and metabolomics. 456 named proteins in total were identified, among which 50 were significantly changed in the pSS. Altered proteins were significantly associated with signaling pathways such as antigen processing and presentation, human immunodeficiency virus 1 infection, and FC gamma R-mediated phagocytosis. Meanwhile, 12 proteins, such as SH3BGRL3, TPM4, and CA1, can be used as potential clinical molecular markers. Moreover, 128 metabolites were significantly expressed in the pSS group. A total of 96 pathways were significantly enriched including central carbon metabolism in cancer, taurine and hypotaurine metabolism, and ABC transporters. Notably, both proteomics and metabolomics enriched glycolysis/gluconeogenesis metabolism, pentose phosphate pathway, and glutathione metabolism pathways. In this study, the progression mechanism of pSS was analyzed and novel biomarkers were identified by proteomics and metabolomics.

Nutritional potential of an edible terrestrial orchid Eulophia nuda LINDL and validation of its traditional claim in arthritis

ETHNO PHARMACOLOGICAL RELEVANCE

Eulophia nuda, locally known as "Amarkand" is an edible orchid, traditionally used as food and ethnomedicine in arthritis, as a blood purifier, vermifuge, in bronchitis, scrofulous glands etc. AIM: The present study focuses on the proximate-nutrient analysis, metabolic profiling of bioactive phenolic acids (PA's) and validation of anti-arthritic activity in E. nuda.

MATERIALS

The proximate, nutrition and element (macro-micro) content were evaluated as per standard protocols. The anti-arthritic activity was evaluated via different Invitro models and bioactive phenolics were quantified through calibrated HPLC-UV (PDA) method, as per ICH guidelines.

RESULTS

The species contains a considerable amount of proximate i.e. ash, fiber, crude alkaloid, total phenolics, and flavonoid. It is a rich source of macro-micro nutrients, carbohydrates and energy, at par with conventional cereals and super-foods like finger millet, foxtail millet etc. It also contains seven PA's viz. gallic acid, protocatechuic acid, caffeic acid, syringic acid, vanillin acid, ferulic acid and quercetin. The PA's content varies from 4.00 to 83.50 μg/ml. The anti-arthritic potential of the plant extract based on several in-vitro-models showed a promising inhibitory effect on inflammation and uric acid synthesis.

CONCLUSION

The study scientifically validates the traditional claims of this traditional orchid as food and ethnomedicine. The species can be commercially explored as a supplement to combat nutritional deficiency among rural communities.

Quercetin-loaded chitosan nanoparticles ameliorate adjuvant-induced arthritis in rats by regulating anti-oxidant enzymes and downregulating pro- and inflammatory cytokines

Rheumatoid arthritis (RA) is an inflammatory condition and associated with the symmetrical synovitis of the joints and cause joint pain. The use of anti-rheumatic drugs is associated with many adverse effects. Quercetin, an important polyphenolic flavonoid, possess anti-inflammatory and anti-rheumatic effects. Quercetin use is limited due to poor absorption and bioavailability. Nanomedicines are used for the targeted drug delivery, hence it reduces the adverse effects of the drug. Based upon these factors, quercetin-loaded chitosan nanoparticles (Q-NPs) were prepared by solvent evaporation method, characterized and their better anti-rheumatic effect with mechanistic insights was validated in Freund's complete adjuvant (FCA)-induced arthritic rats along with safety studies. The animals were divided into five groups, each containing 5 animals. Group I was normal control, group II was arthritic control, while groups III, IV and V were administered with quercetin (15 mg/Kg) and Q-NPs (10 and 20 mg/Kg), respectively. The reduction in ankle diameter, serum oxidative stress markers as well as pro- and inflammatory cytokines, e.g., tumor necrosis factor (TNFα), interleukin (IL-6) were determined. The prepared Q-NPs showed hydrodynamic size of 83.9 nm, polydispersity index of 0.687, entrapment efficiency 90.5% as well as no interaction between quercetin and chitosan in Fourier transform infrared spectroscopy (FTIR). A significant reduction (p < 0.001) in ankle diameter was observed after administration of high-dose Q-NPs (4.32 ± 0.14 cm to 5.13 ± 0.62 cm). There was also reduction (p < 0.001) in levels of TNFα and IL-6 following high-dose Q-NPs (72.56 ± 2.30 and 308.19 ± 11.5 pg). The effect on biochemical tests, hematological parameters and oxidative stress parameters was also found to be significant. Histopathological changes of kidney, liver and ankle also confirmed the anti-rheumatic effect of high-dose Q-NPs. The study concludes that administration of Q-NPs (20 mg/Kg) may be used for the treatment of FCA-induced RA in rats.

Decreased Na+/K+ pump activity in the erythrocyte membrane due to malondialdehyde in rheumatoid arthritis: an in vivo and in silico study

Apart from demonstrating the interaction behavior of malondialdehyde (MDA) with Na⁺/K⁺-ATPase using in silico, the current study aims to investigate the effect of rheumatoid arthritis-related oxidative stress on Na⁺/K⁺-ATPase activity that is present in the erythrocyte cell membrane, which is rich in proteins vulnerable to damage from MDA and other free radicals. The target population of this study consists of 28 rheumatoid arthritis patients and 20 healthy volunteers whose MDA levels and Na⁺/K⁺-ATPase activity were determined. It was shown that MDA levels of rheumatoid arthritis patients increased (p < 0.001) and their Na⁺/K⁺-ATPase activity noticeably decreased when compared to those of healthy individuals. Also, according to this in silico modeling, MDA decreased Na⁺/K⁺-ATPase activity in line with the correlation analyses. Consequently, while elevated levels of MDA in the rheumatoid arthritis group were suggestive of oxidative stress, a decreased Na⁺/K⁺-ATPase-activity led us to speculate that the cellular membrane had sustained injury. Therefore, our results could be useful in explaining how MDA affects Na⁺/K⁺-ATPase activity in the interior of a specific molecular pathway.

Interplay of Environmental, Individual and Genetic Factors in Rheumatoid Arthritis Provocation

In this review, we explore systemization of knowledge about the triggering effects of non-genetic factors in pathogenic mechanisms that contribute to the development of rheumatoid arthritis (RA). Possible mechanisms involving environmental and individual factors in RA pathogenesis were analyzed, namely, infections, mental stress, sleep deprivation ecology, age, perinatal and gender factors, eating habits, obesity and smoking. The non-genetic factors modulate basic processes in the body with the impact of these factors being non-specific, but these common challenges may be decisive for advancement of the disease in the predisposed body at risk for RA. The provocation of this particular disease is associated with the presence of congenital loci minoris resistentia. The more frequent non-genetic factors form tangles of interdependent relationships and, thereby, several interdependent external factors hit one vulnerable basic process at once, either provoking or reinforcing each other. Understanding the specific mechanisms by which environmental and individual factors impact an individual under RA risk in the preclinical stages can contribute to early disease diagnosis and, if the factor is modifiable, might be useful for the prevention or delay of its development.

Does propolis have any effect on rheumatoid arthritis? A review study

Rheumatoid arthritis (RA) is a chronic autoimmune disease in which inflammation and oxidative stress play a key role in its pathophysiology. Complementary therapies along with medications may be effective in the control of RA. Propolis is a natural substance extracted from beehives, which have confirmed anti-inflammatory and antioxidant effects. The present study aimed to review the possible effects of propolis on inflammation, oxidative stress, and lipid profile in patients with RA. English articles in online databases such as PubMed‑Medline, AMED, Google Scholar, EMBASE, Scopus, and Web of Science databases were searched. Pieces of evidence show that supplementation with propolis may have therapeutic effects on RA patients. Due to increased inflammation and oxidative stress in the affected joints of RA patients, propolis could inhibit the inflammatory cascades by inhibiting the nuclear factor kappa B pathway and reducing reactive oxygen species, malondialdehyde, and interleukin-17 by increasing some antioxidants. Therefore, inflammation and pain reduce, helping improve and control RA in patients. Further investigations are required with larger sample sizes and different doses of propolis to demonstrate the definite effects of propolis on various aspects of RA.

Polyphenols Targeting MAPK Mediated Oxidative Stress and Inflammation in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, autoimmune disorder, predominantly symmetric, which causes joint inflammation, cartilage degeneration and bone erosion, resulting in deformity and the loss of physical function. Although the management of RA has steadily improved, the pathophysiological mechanism is incompletely elucidated, and therapeutic options are still limited. Due to shortcomings in the efficacy or safety profiles of conventional RA therapies, therapeutic alternatives have been considered. Therefore, natural extracts containing polyphenolic compounds can become promising adjuvant agents for RA global management, due to their antioxidant, anti-inflammatory and apoptotic properties. Polyphenols can regulate intracellular signaling pathways in RA and can generate different immune responses through some key factors (i.e., MAPK, interleukins (ILs 1 and 6), tumor necrosis factor (TNF), nuclear factor light k chain promoter of activated receptor (NF-κB), and c-Jun N-terminal kinases (JNK)). The critical function of the Toll like-receptor (TLR)-dependent mitogen-activating protein kinase (MAPK) signaling pathway in mediating the pathogenic characteristics of RA has been briefly discussed. Oxidative stress can trigger a change in transcription factors, which leads to the different expression of some genes involved in the inflammatory process. This review aims to provide a comprehensive perspective on the efficacy of polyphenols in mitigating RA by inhibiting signaling pathways, suggesting future research perspectives in order to validate their use.

Biochemical Evaluation of the Effects of Hydroxyurea in Vitro on Red Blood Cells

Hydroxyurea (HU) is a low-cost, low-toxicity drug that is often used in diseases, such as sickle cell anemia and different types of cancer. Its effects on the red blood cells (RBC) are still not fully understood. The in vitro effects of HU were evaluated on the biochemical parameters of the RBC from healthy individuals that were treated with 0.6 mM or 0.8 mM HU for 30 min and 1 h. After 30 min, there was a significant increase in almost all of the parameters analyzed in the two concentrations of HU, except for the pyruvate kinase (PK) activity. A treatment with 0.8 mM HU for 1 h resulted in a reduction of the levels of lipid peroxidation, Fe³⁺, and in the activities of some of the enzymes, such as glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), and PK. After the incubation for 1 h, the levels of H₂O₂, lipid peroxidation, reduced glutathione (GSH), enzymatic activity (hexokinase, G6PD, and superoxide dismutase (SOD) were reduced with the treatment of 0.8 mM HU when compared with 0.6 mM. The results have suggested that a treatment with HU at a concentration of 0.8 mM seemed to be more efficient in protecting against the free radicals, as well as in treating diseases, such as sickle cell anemia. HU appears to preferentially stimulate the pentose pathway over the glycolytic pathway. Although this study was carried out with the RBC from healthy individuals, the changes described in this study may help to elucidate the mechanisms of action of HU when administered for therapeutic purposes.

Peroxisome proliferator-activated receptor-δ-mediated upregulation of catalase helps to reduce ultraviolet B-induced cellular injury in dermal fibroblasts

BACKGROUND

Previous studies suggested that the nuclear receptor peroxisome proliferator-activated receptor (PPAR)-δ plays an essential role in cellular responses against oxidative stress.

OBJECTIVE

To investigate how PPAR-δ elicits cellular responses against oxidative stress in primary human dermal fibroblasts (HDFs) exposed to ultraviolet B (UVB).

METHODS

The present study was undertaken in HDFs by performing real-time polymerase chain reaction, gene silencing, cytotoxicity and reporter gene assay, analyses for catalase and reactive oxygen species, and immunoblot analyses.

RESULTS

The PPAR-δ activator GW501516 upregulated expression of catalase and this upregulation was attenuated by PPAR-δ-targeting siRNA. GW501516-activated PPAR-δ induced catalase promoter activity through a direct repeat 1 response element. Mutation of this response element completely abrogated transcriptional activation, indicating that this site is a novel type of PPAR-δ response element. In addition, GW501516-activated PPAR-δ counteracted the reductions in activity and expression of catalase induced by UVB irradiation. These recovery effects were significantly attenuated in the presence of PPAR-δ-targeting siRNA or the specific PPAR-δ antagonist GSK0660. GW501516-activated PPAR-δ also protected HDFs from cellular damage triggered by UVB irradiation, and this PPAR-δ-mediated reduction of cellular damage was reversed by the catalase inhibitor or catalase-targeting siRNA. These effects of catalase blockade were positively correlated with accumulation of reactive oxygen species in HDFs exposed to UVB. Furthermore, GW501516-activated PPAR-δ targeted peroxisomal hydrogen peroxide through catalase in UVB-irradiated HDFs.

CONCLUSION

The gene encoding catalase is a target of PPAR-δ, and this novel catalase-mediated pathway plays a critical role in the cellular response elicited by PPAR-δ against oxidative stress.

Role of oxidative stress in pathophysiology of rheumatoid arthritis: insights into NRF2-KEAP1 signalling

Rheumatoid arthritis is one of the most prevalent, chronic, inflammatory disorders involving multiple articular and extra-articular complications. Immune deregulation owing to a combinatorial network of cells, inflammatory components, degrading enzymes, angiogenetic factors, exhibiting pleiotropy, synergy, or redundancy, is a critical hallmark for synovial inflammatory milieu reasoning clinical heterogeneity and variability of the disease. As a prototype of autoimmune disease, the pathophysiology of rheumatoid arthritis has been linked to oxidative stress. However, the exact mechanism for these potential driving factors contributing to disease inception and perpetuation is yet elusive. Nuclear factor erythroid 2-related factor 2 - Kelch ECH associating protein 1 (Nrf2-Keap1) pathway, controlled via multifactorial regulation, functions as a ubiquitous, evolutionarily conserved intracellular defense mechanism. Nrf2-Keap1 signalling maintains homeostatic responses against a plethora of environmental or endogenous deviations in cellular growth, death, redox metabolism, inflammation, bone remodelling, detoxification, etc. Administration of antioxidants as an add-on pharmacotherapy along with conventional drugs has been elucidated as a better measure for disease management. Some of the most promising natural and synthetic redox-based therapeutic compounds function as either scavengers of reactive species, or inhibitors of their sources, or activators of an endogenous antioxidant system (Nrf2-Keap1). The present review focuses on the binomial "rheumatoid arthritis-oxidative stress", bringing insights into their pathophysiological interrelationships and Nrf2 signalling, as well as the implications of potential diagnostic oxidative stress biomarkers and therapeutic interventions directed for disease management in patients with rheumatoid arthritis.Highlights:RA has complex etiopathogenesis, evolving from multiple endogenous and exogenous factors with oxidative stress as a critical pathogenic signature.Oxidative damage and damaged compounds could serve as potent biomarkers for disease diagnosis, therapeutic response, and prognosis.One of the supreme cytoprotective signalling cascades, the Nrf2-Keap1 pathway has been known to elicit a protective effect against RA and various other autoimmune, inflammatory, degenerative disorders.Inclusion of natural and synthetic antioxidants has been encouraged by various studies for additional therapy to conventional drugs for better management of the disease.

Prevalence Trend and Disparities in Rheumatoid Arthritis among US Adults, 2005-2018

Rheumatoid arthritis (RA) trends among US adults and disparities in RA patients in recent years have not been well described. We aimed to examine the trend of RA prevalence and disparities among US adults. Data from the National Health and Nutrition Examination Survey (NHANES) of the years 2005–2018 were analyzed to examine the self-reported RA prevalence trend. Age-adjusted RA prevalence stratified by race/ethnicity and socioeconomic status (SES), as well as associated linear trends, were calculated for both genders. The multivariable adjustment was used to evaluate the association between race, SES, and RA. During 2005–2018, there was no significant linear trend in the age-adjusted self-reported RA prevalence among men and women, but significant differences among people from different races, educational levels, and family poverty income ratio (PIR) groups were observed. The RA rate difference was significant for both genders and between Non-Hispanic Caucasians and Non-Hispanic African Americans (both p-value ≤ 0.001). Both men and women with a higher educational level and a higher PIR had a lower age-adjusted RA rate. Age-adjusted RA prevalence fluctuated for both men and women during 2005–2018. Non-Hispanic African Americans and people with low SES had significantly higher age-adjusted RA prevalence and RA risk.

Redox Status in Women with Rheumathoid Arthritis

The aim of this study was to assess oxidative status and to set baseline characteristics for female population with established rheumatoid arthritis. Total of 42 patients with rheumatoid arthritis and 48 age- and sex-matched controls were included in the study. Clinical examination was performed and assessed disease activity. Peripheral blood samples were used for all the assays. The markers of oxidative stress were assessed, including plasma levels of index of lipid peroxidation – thiobarbituric acid reactive substances, hydrogen peroxide, superoxide anion radical, nitrites and activity of superoxide dismutase, catalase and reduced glutathione levels as anti-oxidant parameters. In the patients group, levels of hydrogen peroxide and index of lipid peroxidation were higher than in controls. Patients with rheumatoid arthritis had decreased su-peroxide dismutase and catalase activity compared to healthy subjects. Interestingly, controls had higher levels of nitrites compared to patients. Patients showed a marked increase in reactive oxygen species formation and lipid peroxidation as well as decrease in the activity of antioxidant defense system leading to oxidative stress which may contribute to tissue and cartilage damage and hence to the chronicity of the disease.

Suppressive effects of Streptococcus thermophilus KLDS 3.1003 on some foodborne pathogens revealed through in vitro, in vivo and genomic insights

Foodborne diseases (FBDs) remain a persistent global challenge and recent research efforts suggest that lactic acid bacteria (LAB) strains can contribute towards their prevention and treatment. This study investigates the genetic properties of Streptococcus thermophilus KLDS 3.1003 as a potential probiotic and health-promoting LAB strain as well as its in vitro and in vivo activities against two foodborne pathogens. In vitro, its antimicrobial activities and tolerance levels in simulated bile salts and acids were determined. The cytotoxic effects of the LAB strain in RAW264.7 cells were also evaluated. For in vivo evaluation, 24 BALB/c mice were orally administered control and trial diets for 14 days. Genomic analyses of this strain's bacteriocin configuration, stress response system and multidrug resistance genes were annotated to validate in vitro and in vivo results. In vitro antimicrobial results show that the cells and CFS of S. thermophilus KLDS 3.1003 could inhibit both pathogens with the former being more effective (P < 0.05). In addition, its cell-free supernatant (CFS) could inhibit the growth of both pathogens, with catalase treatment having the highest effect against it. More so, after 3 h of incubation, survivability levels of S. thermophilus KLDS 3.1003 were significantly high (P < 0.05). LPS-induced RAW264.7 cell activities were also significantly reduced by 108-109 CFU mL-1 of S. thermophilus KLDS. In vivo, significant weight losses were inhibited in the TSTEC group compared to the TSTSA group (P < 0.05). Moreover, pathogen-disrupted blood biochemical parameters like HDL, LDL, TP, TG, AST, ALT and some minerals were restored in the respective prevention groups (TSTEC and TSTSA). Genomic analyses showed that S. thermophilus KLDS 3.1003 has bacteriocin-coding peptides, which accounts for its antimicrobial abilities in vitro and in vivo. S. thermophilus KLDS 3.1003 is also endowed with intact genes for acid tolerance, salt-resistance, cold and heat shock responses and antioxidant activities, which are required to promote activities against the selected foodborne pathogens. This study showed that S. thermophilus KLDS 3.1003 has the genomic capacity to inhibit foodborne pathogens' growth in vitro and in vivo, thus qualifying it as a potential probiotic, antimicrobial and bio-therapeutic candidate.

Hydrogen-Peroxide Synthesis and LDL-Uptake Controls Immunosuppressive Properties in Monocyte-Derived Dendritic Cells

BACKGROUND AND AIMS

Induction of myeloid-derived suppressor cells (MDSC) is a critical step in immune cell evasion by different cancer types, including liver cancer. In the liver, hepatic stromal cells orchestrate induction of MDSCs, employing a mechanism dependent on hydrogen peroxide (H2O2) depletion. However, the effects on monocyte-derived dendritic cells (moDCs) are unknown.

METHODS

Monocytes from healthy donors were differentiated to moDCs in the presence of extracellular enzymatic H2O2-depletion (hereinafter CAT-DCs), and studied phenotypically and functionally. To elucidate the underlying molecular mechanisms, we analyzed H2O2- and LDL-metabolism as they are interconnected in monocyte-driven phagocytosis.

RESULTS

CAT-DCs were of an immature DC phenotype, particularly characterized by impaired expression of the costimulatory molecules CD80/86. Moreover, CAT-DCs were able to suppress T-cells using indoleamine 2,3-dioxygenase (IDO), and induced IL10/IL17-secreting T-cells-a subtype reported to exert immunosuppression in acute myeloid leukemia. CAT-DCs also displayed significantly increased NADPH-oxidase-driven H2O2-production, enhancing low-density lipoprotein (LDL)-uptake. Blocking LDL-uptake restored maturation, and attenuated the immunosuppressive properties of CAT-DCs.

DISCUSSION

Here, we report a novel axis between H2O2- and LDL-metabolism controlling tolerogenic properties in moDCs. Given that moDCs are pivotal in tumor-rejection, and lipid-accumulation is associated with tumor-immune-escape, LDL-metabolism appears to play an important role in tumor-immunology.

The Influence of Menopause and Inflammation on Redox Status and Bone Mineral Density in Patients with Rheumatoid Arthritis

Although oxidative stress is considered to be one of the key pathogenic factors in rheumatoid arthritis (RA), there is insufficient knowledge regarding the impact of menopause on redox status in this population. Thus, this study is aimed at assessing the influence of menopause within healthy women and within RA patients as well as the impact of RA in premenopausal and postmenopausal women on redox status, with special reference to bone mineral density (BMD). A total of 90 women were included in the study, 42 with RA and 48 age-matched healthy controls. They were divided into subgroups according to the presence of menopause. Following oxidative stress parameters were measured spectrophotometrically: index of lipid peroxidation (measured as TBARS), nitrites (NO2 -), superoxide anion radical (O2 -), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). BMD was assessed by using a dual-energy X-ray absorptiometry scanner. Comorbidities and drug history were recorded. The levels of H2O2 and TBARS were elevated in patients with RA, while NO2 - and O2 - increased in healthy women, both in premenopausal and postmenopausal groups. SOD activity decreased in postmenopausal RA patients. BMD was reduced in postmenopausal RA women. There was a correlation between NO2 - and O2 - with Health Assessment Questionnaire (HAQ) index in RA patients. Given that postmenopausal state was associated with elevated oxidative stress within healthy women and that menopausal state did not affect redox homeostasis within RA patients, but the redox homeostasis was altered in both RA groups compared to healthy women, it can be presumed that impaired redox status in RA occurred due to presence of the disease, irrespective of age. Moreover, menopause attenuates BMD reduction in women with RA. These results may indicate the need for therapeutic use of antioxidants in the form of supplements in women with RA, regardless of age.

Insights in the Role of Lipids, Oxidative Stress and Inflammation in Rheumatoid Arthritis Unveiled by New Trends in Lipidomic Investigations

Rheumatoid arthritis (RA) is a highly debilitating chronic inflammatory autoimmune disease most prevalent in women. The true etiology of this disease is complex, multifactorial, and is yet to be completely elucidated. However, oxidative stress and lipid peroxidation are associated with the development and pathogenesis of RA. In this case, oxidative damage biomarkers have been found to be significantly higher in RA patients, associated with the oxidation of biomolecules and the stimulation of inflammatory responses. Lipid peroxidation is one of the major consequences of oxidative stress, with the formation of deleterious lipid hydroperoxides and electrophilic reactive lipid species. Additionally, changes in the lipoprotein profile seem to be common in RA, contributing to cardiovascular diseases and a chronic inflammatory environment. Nevertheless, changes in the lipid profile at a molecular level in RA are still poorly understood. Therefore, the goal of this review was to gather all the information regarding lipid alterations in RA analyzed by mass spectrometry. Studies on the variation of lipid profile in RA using lipidomics showed that fatty acid and phospholipid metabolisms, especially in phosphatidylcholine and phosphatidylethanolamine, are affected in this disease. These promising results could lead to the discovery of new diagnostic lipid biomarkers for early diagnosis of RA and targets for personalized medicine.

Genomic and in vitro properties of the dairy Streptococcus thermophilus SMQ-301 strain against selected pathogens

Cumulative studies have suggested that probiotic bacterial strains could be an effective alternative in inhibiting conditions caused by foodborne and vaginal pathogens. The use of genomic techniques is becoming highly useful in understanding the potential of these beneficial microorganisms. This study presents some genomic and in vitro properties of the Streptococcus thermophilus SMQ-301 strain against foodborne and vaginal pathogens (Staphylococcus aureus, Escherichia coli, and Gardnerella vaginalis) to validate its use in dairy food formulations. Genomic analyses include bacteriocin production, stress response systems, antioxidant capability, and RAST-based functional annotation. In vitro investigations focused on the antimicrobial effects of the S. thermophilus SMQ-301 cell-free solution (CFS) against the selected pathogens after enzymatic actions and pH treatments, assessment of cytotoxic effects using murine RAW264.7 cells, and assessment of organic acid production levels using supplementary carbon sources. The results show that the S. thermophilus SMQ-301 genome possesses essential pathways for stress management, antioxidant activities, and bacteriocin production. For the first time, the bacteriocin-producing peptides of S. thermophilus SMQ-301 are reported, which gives an insight into its inhibitory potential. In vitro, the CFS of S. thermophilus SMQ-301 had significant (P < 0.05) antimicrobial effects on the selected pathogens, with S. aureus ATCC25923 being the most resistant. All antimicrobial activities of the CFS against the selected pathogens were eliminated at pH 6.5 and 7.0. S. thermophilus SMQ-301 CFS yielded the highest lactic (25.58 ± 0.24 mg mL-1) and acetic (5.53 ± 0.12 mg mL-1) acid production levels, with 1% fructooligosaccharide (P < 0.05). The S. thermophilus SMQ-301 strain also lowered murine RAW264.7 cell activities from 101.77% (control) to 80.16% (T5 - RAW264.7 cells + 1 × 109 CFU mL-1 cells) (P < 0.05). This study showed that although the S. thermophilus SMQ-301 strain had excellent genomic characteristics, the in vitro effects varied markedly against all three pathogens. In all, the S. thermophilus SMQ-301 strain has promising applications as a potential probiotic in the food and allied industries.

Evaluation of oxidative and an­tioxidant status in dairy calves before and after weaning

Weaning is a stressful step in calf rearing which can lead to oxidative stress. The purpose of the present study was to investigate oxidative stress and antioxidant status in calves pre and post weaning. A total of 22 clinically healthy female Holstein calves at the same age were selected and their blood samples were examined to measure the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) in red blood cells and serum malondialdehyde (MDA) concentration. Sampling was performed in 4 consecutive stages: 7 days pre-weaning, the day of weaning, 24 and 72 hours after it. The results indicated that the activity of SOD and GPx enzymes increased significantly on the weaning day compared to the previous week. CAT activity increased 24 and 72 hours after weaning and its increase was significant 72 hours after weaning compared to the day of weaning. An increase was observed in MDA level on the day of weaning compared to a week before, and the trend was towards increase after the weaning. Weaning stress leads to disturbances of oxidative system balance and causes oxidative damage in calves. This imbalance can be probably resolved by improving the antioxidant system and supplementing antioxidants such as vitamins E and C against free radicals produced during weaning.

In Vivo Effects of Nonselective, Partially Selective, and Selective Non Steroidal Anti-Inflammatory Drugs on Lipid Peroxidation and Antioxidant Enzymes in Patients with Rheumatoid Arthritis: A Clinical Study

Background

The relationship between oxidative stress, decreased antioxidant status, and rheumatoid arthritis (RA) has been widely investigated. To date, few clinical studies have assessed the role of conventional nonsteroidal anti-inflammatory drugs (NSAIDs) in the modulation of oxidative stress in patients with RA.

Aim

The aim of this study was to compare the effects of nonselective, partially selective, and selective cyclooxygenase (COX) inhibitors on markers of oxidative stress in patients with RA.

Materials and Methods

Thirty RA patients were enrolled in this open label, prospective study for 12 weeks and randomly assigned to either group receiving diclofenac 100 mg, meloxicam 15 mg, or celecoxib 200 mg daily (n = 10 in each group). Patients were evaluated for superoxide dismutase (SOD) and serum malondialdehyde (MDA) as oxidative markers at the baseline and at the end of 12 weeks. Various parameters for efficacy were also assessed.

Results

The baseline values of the SOD enzyme were significantly lower and MDA values were significantly elevated in patients randomized to the three treatment groups as compared to the control group (P < 0.05). MDA level was significantly decreased in patients across all the treatment groups (P < 0.05) after 12 weeks. There was an improvement in mean SOD enzyme levels at the end of 12 weeks; the difference for SOD was significant as compared to the baseline in the meloxicam group only (P < 0.05) but not in diclofenac- and celecoxib-treated patients. Significant improvement was observed in all the treatment groups as regards patient assessment of pain visual analog scale, tender and swollen joint count, and patient global assessment.

Conclusions

Diclofenac, meloxicam, and celecoxib carry antioxidant effects to a variable extent. NSAID possesses additional mechanism independent of COX inhibition which modulates oxidative stress.

Smoking cessation intervention for reducing disease activity in chronic autoimmune inflammatory joint diseases

BACKGROUND

Chronic inflammatory joint diseases (IJDs) affect 1% to 2% of the population in developed countries. IJDs include rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), and other forms of spondyloarthritis (SpA). Tobacco smoking is considered a significant environmental risk factor for developing IJDs. There are indications that smoking exacerbates the symptoms and worsens disease outcomes.

OBJECTIVES

The objective of this review was to investigate the evidence for effects of smoking cessation interventions on smoking cessation and disease activity in smokers with IJD.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library; PubMed/MEDLINE; Embase; PsycINFO; the Cumulative Index to Nursing and Allied Health Literature (CINAHL); and three trials registers to October 2018.

SELECTION CRITERIA

We included randomised controlled trials testing any form of smoking cessation intervention for adult daily smokers with a diagnosis of IJD, and measuring smoking cessation at least six months after baseline.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included two studies with 57 smokers with a diagnosis of rheumatoid arthritis (RA). We identified no studies including other IJDs. One pilot study compared a smoking cessation intervention specifically for people with RA with a less intensive, generic smoking cessation intervention. People included in the study had a mean age of 56.5 years and a disease duration of 7.7 years (mean). The second study tested effects of an eight-week cognitive-behavioural patient education intervention on cardiovascular disease (CVD) risk for people with RA and compared this with information on CVD risk only. The intervention encouraged participants to address multiple behaviours impacting CVD risk, including smoking cessation, but did not target smoking cessation alone. People included in the study had a mean age of 62.2 years (intervention group) and 60.8 years (control group), and disease duration of 11.6 years (intervention group) and 14.1 years (control group). It was not appropriate to perform a meta-analysis of abstinence data from the two studies due to clinical heterogeneity between interventions. Neither of the studies individually provided evidence to show benefit of the interventions tested. Only one study reported on adverse effects. These effects were non-serious, and numbers were comparable between trial arms. Neither of the studies assessed or reported disease activity or any of the predefined secondary outcomes. We assessed the overall certainty of evidence as very low due to indirectness, imprecision, and high risk of detection bias based on GRADE.

AUTHORS' CONCLUSIONS

We found very little research investigating the efficacy of smoking cessation intervention specifically in people with IJD. Included studies are limited by imprecision, risk of bias, and indirectness. Neither of the included studies investigated whether smoking cessation intervention reduced disease activity among people with IJD. High-quality, adequately powered studies are warranted. In particular, researchers should ensure that they measure disease markers and quality of life, in addition to long-term smoking cessation.

Thiol/Disulfide homeostasis in patients with rheumatoid arthritis

BACKGROUND

Oxidative stress may play an important role in rheumatoid arthritis (RA) etiopathogenesis. The thiol group is a very strong antioxidant. In this study, we aimed to investigate the presence of oxidative stress in patients with RA by evaluating thiol/disulfide homeostasis.

MATERIAL AND METHODS

A total of 50 female RA patients and 50 healthy female controls were included in this study. Thiol and disulfide values were calculated utilizing novel methods.

RESULTS

Native thiol (p < 0.001) and total thiol (p < 0.001) levels of RA patients were significantly lower compared to values in the control group. However, the disulfide (p < 0.001) levels of RA patients were strongly higher than in healthy individuals. A negative correlation was found between thiol and disease activity score-28 among the patients, whereas a positive correlation was found between disulfide and disease activity score-28 among the patients.

CONCLUSION

We found that the thiol-disulfide rate deteriorated in RA patients, with the proportion of disulfide increasing. There is a strong correlation between the decrease in thiol levels, increase in disulfide levels and the disease activity scores.

The association of CAT-262C/T polymorphism with catalase activity and treatment response in juvenile idiopathic arthritis

Oxidative stress is believed to be of great importance for both the etiology and the persistence of juvenile idiopathic arthritis (JIA). The aim of this study was to investigate the association of -262C/T polymorphism of the catalase (CAT) gene with JIA, as well as to evaluate whether this polymorphism can influence plasma CAT activity and outcome in JIA patients treated with etanercept. A total of 154 subjects (60 JIA patients and 94 healthy volunteers) were screened for CAT-262C/T gene polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Plasma CAT activity was determined using the spectrophotometric method according to Goth, prior to and 12 months after anti-TNF (etanercept) therapy. Clinical outcome was assessed using the JIA ACR (American College of Rheumatology) response criteria. The genotype and allele frequency distributions of CAT-262C/T polymorphism in the patients were significantly different from those of the controls (p = 0.014, p = 0.006). The TT genotype (polymorphic homozygous) was associated with a 4.36-fold higher likelihood of having JIA (95% CI 1.545-12.323, p = 0.005) as compared to the CC genotype (wild-type). At month 12 of treatment, JIA patients, carriers of the CC genotype, showed significantly higher plasma CAT activity (p = 0.004) and achieved the JIA ACR 70 response more often (p = 0.003) than the patients, carriers of the CT/TT genotype. This is the first study implying the possible association of CAT-262C/T polymorphism with JIA. The results suggest the potential protective effect of the CC genotype, with regard to CAT activity and treatment outcome.

Influence of eugenol on oxidative stress biomarkers in the liver of carrageenan-induced arthritis rats

Background Eugenol is the foremost constituent of clove oil and widely distributed in many plants. It possesses many pharmaceutical applications, including antioxidant, anti-inflammatory, and anti-tumorigenic properties, among others. This study evaluates the influence of eugenol on oxidative stress biomarkers in the liver of carrageenan-induced arthritis (CIA) rats. Methods Sixty albino rats were randomly divided into 10 (n=6) groups. Group I is the control group that received saline solution orally. Groups II and VII rats received 2.5 mg/kg of eugenol orally (EUG-2.5). Rats in groups III/VIII and IV/IX received 5 and 10 mg/kg of eugenol orally (EUG-5 and EUG-10), respectively. Groups V and X received 0.2 mg/kg of dexamethasone (DEX-0.2) orally. Groups VI to X were injected with 1% carrageenan intra-articularly. Behavioral studies were conducted after 21 days of treatment. Thereafter, the animals were sacrificed, and the livers were isolated and used for biochemical analysis. Results Reduced body weight in arthritic rats was recorded compared to normal controls. Reduced tibiofemoral joint edema and increased spontaneous movement were observed in CIA rats with decreased superoxide dismutase, catalase, reduced glutathione (GSH), glutathione peroxidase, and GSH S-transferase activities compared with the normal control group. Increased endogenous enzyme activities and decreased elevated lipid peroxidation were also observed after eugenol treatment. Conclusion Eugenol ameliorates carrageenan-induced oxidative stress in the liver of arthritic rats.

Role of hydrotherapy in the amelioration of oxidant-antioxidant status in rheumatoid arthritis patients

AIM

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease. Reactive oxygen species (ROS) are involved in the pathophysiology of RA. Moderate intensity exercises have been reported to have anti-oxidant and anti-inflammatory effects. The aim of this study was to evaluate the effect of hydrotherapy on oxidant-antioxidant status in RA patients.

METHODS

Forty RA patients and 30 age- and sex-matched healthy controls were included in this study. RA patients were subdivided into two groups: the first group (n = 20) received treatment with conventional RA drugs, while the second group (n = 20) received hydrotherapy along with the conventional drugs for a period of 12 weeks. Disease Activity Score of 28 joints (DAS-28), ROS level, protein oxidation, lipid peroxidation, DNA damage and the activities of antioxidant enzymes were evaluated before and after 12 weeks of treatment.

RESULTS

RA patients showed a significant change in the oxidative stress biomarkers (ROS, P < 0.01; ferric reducing antioxidant potential, P < 0.001; malondialdehyde, P < 0.01; protein carbonyl, P < 0.001; tail length, P < 0.05) and decrease in the activities of anti-oxidant enzymes (superoxide dismutase [SOD], P < 0.01; glutathione peroxidase [GPx], P < 0.001). Conventional drug treatment has not produced any significant change in these parameters. However, cotreatment of drugs with hydrotherapy has decreased protein, lipid and DNA oxidation by increasing the activities of antioxidant enzymes (SOD and GPx).

CONCLUSION

Our results indicate that hydrotherapy along with drugs has reduced the severity of disease (DAS-28) by ameliorating the oxidant-antioxidant status in RA patients. Thus, in addition to conventional drugs, RA patients should be advised to have hydrotherapy (moderate intensity exercise) in their treatment regimen.

Smoking-induced aggravation of experimental arthritis is dependent of aryl hydrocarbon receptor activation in Th17 cells

BACKGROUND

Epidemiologic studies have highlighted the association of environmental factors with the development and progression of autoimmune and chronic inflammatory diseases. Among the environmental factors, smoking has been associated with increased susceptibility and poor prognosis in rheumatoid arthritis (RA). However, the immune and molecular mechanism of smoking-induced arthritis aggravation remains unclear. The transcription factor aryl hydrocarbon receptor (AHR) regulates the generation of Th17 cells, CD4 T cells linked the development of autoimmune diseases. AHR is activated by organic compounds including polycyclic aromatic hydrocarbons (PAHs), which are environmental pollutants that are also present in cigarette smoke. In this study, we investigated the role of AHR activation in the aggravation of experiment arthritis induced by exposure to cigarette smoke.

METHODS

Mice were exposed to cigarette smoke during the developmental phase of antigen-induced arthritis and collagen-induced arthritis to evaluate the effects of smoking on disease development. Aggravation of articular inflammation was assessed by measuring neutrophil migration to the joints, increase in articular hyperalgesia and changes in the frequencies of Th17 cells. In vitro studies were performed to evaluate the direct effects of cigarette smoke and PAH on Th17 differentiation. We also used mice genetically deficient for AHR (Ahr KO) and IL-17Ra (Il17ra KO) to determine the in vivo mechanism of smoking-induced arthritis aggravation.

RESULTS

We found that smoking induces arthritis aggravation and increase in the frequencies of Th17 cells. The absence of IL-17 signaling (Il17ra KO) conferred protection to smoking-induced arthritis aggravation. Moreover, in vitro experiments showed that cigarette smoke can directly increase Th17 differentiation of T cells by inducing AHR activation. Indeed, Ahr KO mice were protected from cigarette smoke-induced arthritis aggravation and did not display increase in TH17 frequencies, suggesting that AHR activation is an important mechanism for cigarette smoke effects on arthritis. Finally, we demonstrate that PAHs are also able to induce arthritis aggravation.

CONCLUSIONS

Our data demonstrate that the disease-exacerbating effects of cigarette smoking are AHR dependent and environmental pollutants with AHR agonist activity can induce arthritis aggravation by directly enhancing Th17 cell development.

Quercetin attenuates zymosan-induced arthritis in mice

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by articular lesions, recruitment of inflammatory cells and increased levels of pro-inflammatory cytokine. The intra-articular administration of zymosan is an experimental model that promotes inflammatory parameters resembling RA. Therefore, this model was used to investigate the efficacy of quercetin as a treatment of articular inflammation. Treatment with quercetin dose-dependently reduced zymosan-induced hyperalgesia, articular edema and the recruitment of neutrophils to the knee joint cavity. Histological analysis confirmed that quercetin inhibited zymosan-induced arthritis. The treatment with quercetin also inhibited zymosan-induced depletion of reduced glutathione (GSH) levels, TNFα and IL-1β production, and gp91^phox, prepro-endothelin-1 (preproET-1), and cyclooxygenase-2 mRNA expression. These molecular effects of quercetin were related to the inhibition of the nuclear factor kappa-B and induction of Nuclear factor erythroid 2- related factor (Nrf2)/home oxygenase (HO-1) pathway. Thus, quercetin exerted anti-inflammatory, analgesic and antioxidant effects in experimental arthritis, suggesting quercetin is a possible candidate for arthritis treatment.

Catalase and its mysteries

Catalase is one of the firsts in every realm of biological sciences. At the same time it also has a number of unusual features. It has one of the highest turnover numbers of all enzymes. It is essential for neutralizing the noxious hydrogen peroxide both in the nature and the various industries such as dairy, textile and pharmaceutics. It also has the merit of being one of the first protein crystals to be isolated. Ironically its three-dimensional structure was discerned some forty years later. However through the times this senile enzyme has continued to intrigue the scientists by surprising facts and phenomena, such as peculiar interweaving of subunits and remarkable thermal stability. It is also known for suicide inactivation by its own substrate. Catalase is known to be implicated in various medical scenarios and its levels have served as a marker in that capacity. It has even been incorporated into several pharmaceuticals. This review strives to clarify these perspectives. It also draws attention to the biophysical contributions offered by thermodynamics and kinetics in these discoveries. The ultimate aim of this review, however, is to state that the venerable catalase will continue to bewilder us with its mysteries well into the twenty-first century.

Smoking and susceptibility to rheumatoid arthritis in a Swedish population-based case-control study

Smoking is one of the most established risk factors for rheumatoid arthritis (RA). The aim of this study was to estimate how age at smoking debut, smoking cessation, duration, intensity, and cumulative dose of smoking influence the risk of developing anti-citrullinated peptide antibodies (ACPA) positive and ACPA negative RA. The present report is based on a Swedish population-based, case–control study with incident cases of RA (3655 cases, 5883 matched controls). Using logistic regression models, subjects with different smoking habits were compared regarding risk of developing the two variants of RA, by calculating odds ratios (OR) with 95% confidence intervals (CI). Smoking increased the risk of developing both ACPA positive (OR 1.9, 95% CI 1.7–2.1) and ACPA negative RA (OR 1.3, 95% CI 1.2–1.5). For both subsets of RA, there seemed to be a threshold (~ 2.5 pack years for ACPA positive RA and ~ 5 pack years for ACPA negative RA) below which no association between smoking and RA occurred. A dose–response association was observed between cumulative dose of smoking and risk of developing ACPA positive RA (p value for trend < 0.0001). Duration of smoking had a higher influence on the association between smoking and RA than did intensity of smoking. For both subsets of RA, the detrimental effect of smoking decreased after smoking cessation. Twenty years after smoking cessation, there was no longer an association between smoking and risk of ACPA negative RA, whereas the association between smoking and ACPA positive RA risk persisted and was dependent on the cumulative dose of smoking. Smoking increases the risk of both subsets of RA with a more pronounced influence on the risk of ACPA positive RA. Preventive measures in order to reduce smoking are essential and may result in a decline in RA incidence.

Relationship Between Smoking and Structural Damage, Autoimmune Antibodies, and Disability in Rheumatoid Arthritis Patients

Objectives

This study aims to investigate the relationship between smoking and structural damage, autoimmune antibodies, and disability in rheumatoid arthritis (RA) patients.

Patients and methods

This cross-sectional study included 165 RA patients (36 males, 129 females; mean age 52.4±12.8 years; range 21 to 82 years). Disease duration, age at disease onset, smoking habits, rheumatoid factor (RF), and anti-cyclic citrullinated peptide levels were recorded. Morning stiffness, pain with visual analog scale, Health Assessment Questionnaire Scores And Disease Activity Score 28 were calculated. Patients' standard hand radiographs were evaluated.

Results

Patients were divided into three groups according to their smoking habits. Ninety-nine patients (60%) were never smokers, 45 patients (27.3%) were long-term smokers and 21 patients (12.7%) were new smokers. Three groups were compared for disease activity. Disease activity score 28 scores were 3.2±1.2, 3.2±1.3, and 3.2±1.4, respectively (p>0.05). The erosion score (2.6±5.8, 7.1±10.9, and 11.1±19.2, respectively) and joint space narrowing score (9.9±7.3, 18.6±14.9, and 17.3±12.3, respectively) according to modified Sharp method were significantly lower in never smokers group than other groups (p<0.05). RF titrations were 55.2±58.9, 60.5±63.1, and 84.9±71.5, respectively, and levels of long-term smokers group were significantly higher than the other groups (p<0.05). Joint space narrowing score was 16.2±11.9 and 6.4±10.4 in RF (+) and RF (-) patients, respectively (p<0.05). There was no significant relationship between anti-cyclic citrullinated peptide levels and others parameters.

Conclusion

Although smoking is known as a poor prognostic factor in RA, there was no correlation between disease activity and smoking in our study. However, less radiographic damage was found in never smokers. Smoking does not appear to correlate with RA disease activity but it may be effective in the long-term joint damage.

Management and Risk Reduction of Rheumatoid Arthritis in Individuals with Obstructive Sleep Apnea: A Nationwide Population-Based Study in Taiwan

STUDY OBJECTIVES

To explore associations between obstructive sleep apnea (OSA) and autoimmune diseases and evaluate whether OSA management reduces the incidence of autoimmune diseases.

METHODS

This was a retrospective cohort study using nationwide database research. The data was from 105,846 adult patients in whom OSA was diagnosed and recorded in the Taiwan National Health Insurance Research Database between 2002 and 2011 were the patients were analyzed retrospectively. Patients with antecedent autoimmune diseases were excluded. A comparison cohort of 423,384 participants without OSA served as age- and sex-matched controls. Multivariable Cox regression analysis was performed on both cohorts to compute risk of autoimmune diseases during follow-up. Time-dependent OSA treatment effect was analyzed among patients with OSA. There were no interventions.

RESULTS

Among patients with OSA, overall risk for incident autoimmune diseases was significantly higher than that in controls (adjusted hazard ratio [HR] = 1.95, 95% confidence interval [CI] = 1.66-2.27). Risk for individual autoimmune diseases, including rheumatoid arthritis (RA), Sjögren syndrome (SS), and Behçet disease, was significantly higher in patients with OSA than in controls (HRs [95% CI]: RA 1.33 [1.03-1.72, SS 3.45 [2.67-4.45] and Behçet disease 5.33 [2.45-12.66]). Increased risk for systemic lupus erythematosus (HR 1.00 [0.54-1.84]) and systemic sclerosis (HR 1.43 [0.51-3.96]) did not reach statistical significance. Patients with OSA receiving treatment had an overall reduced risk of RA and other autoimmune diseases (time-dependent HRs [95% CI]: 0.22 [0.05-0.94] and 0.51 [0.28-0.92], respectively).

CONCLUSIONS

Patients with OSA are associated with higher risk for developing RA, SS, and Behçet disease. OSA management is associated with reduced risk of RA.

Influence of Periodontal Clinical Status on Salivary Levels of Glutathione Reductase

BACKGROUND

Inadequate antioxidant balance may play a role in the excessive tissue breakdown in periodontitis. Because aggressive periodontitis (AgP) not only differs from chronic periodontitis (CP) in terms of clinical manifestations, this study investigates whether the salivary levels of glutathione reductase (GR) may be linked with periodontal status.

METHODS

Saliva samples from patients with CP (n = 121), patients with AgP (n = 18), and healthy controls (n = 69) were collected. Periodontal status was assessed by criteria based on probing depth, clinical attachment level, and extent and severity of periodontal breakdown. GR salivary levels were analyzed by spectrophotometry. The association among GR concentration and CP or AgP was analyzed individually and adjusted for confounding using multivariate binary logistic regression models.

RESULTS

GR levels not only differed significantly between the two periodontitis groups, being significantly greater in patients with AgP, but also were significantly greater than those observed in healthy controls. Synchronously, positive significant correlations between salivary GR concentration and clinical parameters were observed. After binary logistic regression analysis, both GR salivary levels ≥15.38 and ≥24.20 mU/mL were associated independently with CP and AgP, respectively. A significant interaction effect was also detected between increased GR salivary concentration and aging in the CP group.

CONCLUSIONS

Increased GR salivary concentration may be a strong/independent prognostic indicator of the amount and extent of oxidative stress-induced periodontal damage in both CP and AgP. Likewise, saliva samples might reflect an interactive effect of GR levels associated with the aging-related cumulative characteristics of periodontal damage in CP.

Oxidative Stress Relevance in the Pathogenesis of the Rheumatoid Arthritis: A Systematic Review

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease whose pathogenic mechanisms remain to be elucidated. The oxidative stress and antioxidants play an important role in the disease process of RA. The study of oxidants and antioxidants biomarkers in RA patients could improve our understanding of disease pathogenesis; likely determining the oxidative stress levels in these patients could prove helpful in assessing disease activity and might also have prognostic implications. To date, the usefulness of oxidative stress biomarkers in RA patients is unclear and the evidence supporting them is heterogeneous. In order to resume and update the information in the status of oxidants and antioxidants and their connection as biomarkers in RA, we performed a systematic literature search in the PubMed database, including clinical trials published in the last five years using the word combination "rheumatoid arthritis oxidative stress". In conclusion, this review supports the fact that the oxidative stress is an active process in RA pathogenesis interrelated to other better known pathogenic elements. However, some controversial results preclude a definite conclusion.

Increased Reactive Oxygen Species Formation and Oxidative Stress in Rheumatoid Arthritis

Background

Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder. Highly reactive oxygen free radicals are believed to be involved in the pathogenesis of the disease. In this study, RA patients were sub-grouped depending upon the presence or absence of rheumatoid factor, disease activity score and disease duration. RA Patients (120) and healthy controls (53) were evaluated for the oxidant—antioxidant status by monitoring ROS production, biomarkers of lipid peroxidation, protein oxidation and DNA damage. The level of various enzymatic and non-enzymatic antioxidants was also monitored. Correlation analysis was also performed for analysing the association between ROS and various other parameters.

Methods

Intracellular ROS formation, lipid peroxidation (MDA level), protein oxidation (carbonyl level and thiol level) and DNA damage were detected in the blood of RA patients. Antioxidant status was evaluated by FRAP assay, DPPH reduction assay and enzymatic (SOD, catalase, GST, GR) and non-enzymatic (vitamin C and GSH) antioxidants.

Results

RA patients showed a higher ROS production, increased lipid peroxidation, protein oxidation and DNA damage. A significant decline in the ferric reducing ability, DPPH radical quenching ability and the levels of antioxidants has also been observed. Significant correlation has been found between ROS and various other parameters studied.

Conclusion

RA patients showed a marked increase in ROS formation, lipid peroxidation, protein oxidation, DNA damage and decrease in the activity of antioxidant defence system leading to oxidative stress which may contribute to tissue damage and hence to the chronicity of the disease.

Amelioration of FCA induced arthritis on topical application of curcumin in combination with emu oil

OBJECTIVE

The aim of the present study was to investigate the skin penetration potential of emu oil and the possibility of enhancing the antiarthritic potential of lipophilic bioactive curcumin, which has poor permeability through biological membranes.

METHODS

Solubility and ex vivo skin permeation studies were performed with water, corn oil, and emu oil as a vehicle using curcumin as a model drug. Carrageenan induced inflammation and Freund's complete adjuvant-induced arthritic rat models were used to evaluate enhanced antiinflammatory and antiarthritic effect of curcumin in combination of emu oil via topical route.

RESULTS

The skin permeation study resulted in the combination of emu oil with curcumin enhancing the flux 1.84 and 4.25 times through the rat skin compared to corn oil and water, respectively. Results of carrageenan induced rat paw edema model demonstrated that percentage of paw inhibition shown by curcumin-emu oil combination was 1.42-fold more compared to the total effect shown by both groups treated with curcumin aqueous suspension and emu oil per se. In Freund's complete adjuvant-induced arthritic model, the combined treatment was effective in bringing significant changes in the functional, biochemical, histopathologic, and radiologic parameters. Topical application of curcumin-emu oil combination resulted in significant reduced levels of proinflammatory mediators TNF-α, IL-1 β, and IL-6 (P < 0.05, 0.001, and 0.01, respectively) compared to arthritic animals.

CONCLUSION

Topical delivery of curcumin with emu oil holds promise as a noninvasive and efficacious intervention for the treatment of inflammatory arthritis and it assists in further development of a topical formulation of curcumin using emu oil as a vehicle.

Salivary Concentration of Oxidative Stress Biomarkers in a Group of Patients with Peri-Implantitis: A Transversal Study

PURPOSE

The purpose of this study was to know if peri-implantitis causes an increase in the total salivary concentration of oxidative stress markers.

MATERIALS AND METHODS

Seventy patients, 28 men and 42 women, 60 of them with dental implants, 30 of which had peri-implantitis and 30 were healthy. The remaining 10 were the control group: healthy subjects without implants. The average number of implants per patient was 4.70 ± 2.29 in the peri-implantitis group and 2 70 ± 2.11 in the control group. Periodontal/peri-implant variables were assessed, including bleeding index, gingival index, clinical attachment level, probing depth, presence of pockets larger than 4 and 6 mm, pain to percussion, suppuration, gingival hyperplasia or granuloma, crestal bone loss (both mesially and distally), evaluated through periapical radiography. Saliva samples from the 70 subjects were collected for measurement of malondialdehyde high performance liquid chromatography (HPLC) and myeloperoxidase (enzyme-linked immunosorbent assay analysis) concentrations.

RESULTS

Implants affected with peri-implantitis had an average follow-up of 26.40 ± 7.97 months. 4.12% of implants with peri-implantitis had a painful response to percussion. 2.06% showed suppuration; 25.77% had granuloma. The mean crestal bone loss in implants wtih peri-implantitis was 3.78 ± 1.17 mm. Total salivary malondialdehyde concentration in the peri-implantitis group (0.52 ± 0.37 μM/l) was slightly higher than that in the group with healthy implants (0.40 ± 0.16 μM/l) and also slightly higher than that in the group of healthy patients without implants (0.41 ± 0.79 μM/l), although the difference was not statistically significant, p value = .442. Myeloperoxidase concentration was slightly higher in the peri-implantitis group (12.32 ± 2.17 ng/ml) than in the group with healthy implants (11.54 ± 2.80 ng/ml) and the group of healthy patients without implants (11.86 ± 2.67 ng/ml), without statistically significant differences, p value = .584.

CONCLUSIONS

The salivary concentration of oxidative stress markers in patients with peri-implantitis and without periodontitis is not higher than that found in healthy patients.

Effect of galantamine on adjuvant-induced arthritis in rats

Stimulation of the vagus nerve suppresses cytokine production and macrophage activation, via the interaction of its neurotransmitter acetylcholine (ACh) with the α7 subunit of the nicotinic acetylcholine receptor (α7nAChR), present on neurons and inflammatory cells. The present study aimed to verify the potential anti-inflammatory effect of galantamine against experimental arthritis induced in rats. Fourteen days post adjuvant injection, Sprague-Dawley rats were treated orally with three doses of galantamine (1.25, 2.5 and 5 mg/kg) or leflunomide (10 mg/kg) for 2 weeks and arthritis progression was assessed by hind paw swelling. Additionally, serum biomarkers, viz., anti-cyclic citrullinated peptide antibodies (Anti-CCP), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and monocyte chemoattractant protein-1 (MCP-1) were measured. Radiological examination of the hind paws was also carried out to evaluate the degree of joint damage. Adjuvant arthritis led to a significant weight loss, marked swelling of the hind paw and alteration in the serum levels of anti-CCP, TNF-α, IL-10 and MCP-1. These alterations were associated with significant radiological changes of the joints. Galantamine, in a dose-dependent manner, reduced significantly all biomarkers of inflammation, with the highest dose showing the best beneficial anti-inflammatory effect that was superior in magnitude to the reference drug leflunomide in most of the studied parameters. In conclusion, these results suggest that galantamine may represent a novel, inexpensive and effective therapeutic strategy in the treatment of rheumatoid arthritis.