Assessment of lipid peroxidation and antioxidant status in rheumatoid arthritis and osteoarthritis patients

Protective potential of Bacillus subtilis (NMCC-path-14) against extraarticular manifestations during acute and sub-acute phase of arthritis using mice model

Extra-articular manifestations (EAM), which are associated with rheumatoid arthritis (RA), affect the quality of life of patients and are one of the critical causes of early mortality. This study was aimed at investigating whether Bacillus subtilis NMCC-path-14 (1 × 108 CFU/animal/day) could serve as a valuable therapeutic agent in managing EAM using complete Freund's adjuvant (CFA) induced arthritis during acute and sub-acute phases. Arthritis was induced using intra-dermal administration of CFA in the right hind paw of mice on day 1. Dexamethasone (Dexa) (5 mg/kg/day/animal) was used as a standard treatment. Animals in Dexa and Bacillus subtilis concurrent treatment (BS-CT) received treatments on day 1. The Bacillus subtilis pre-treatment (BS-PT) group received a probiotic dose 7 days before arthritis induction. Parameters like body weight, relative organ weight, colon length, hematology, serum biochemistry, antioxidant capacity, and histopathology of liver, kidney, spleen, colon, stress-related behavioral changes, and cortisol levels were evaluated on days 7 (acute) and 14 (sub-acute). Dexa failed to manage the EAM in arthritic mice and instead exacerbated them. On the other hand, B. subtilis NMCC-path-14 significantly declined EAM with no notable side effects, highlighting its safety and effectiveness. The current data show that B. subtilis NMCC-path-14 may be an alternative option for arthritis treatment that can reduce systemic symptoms associated with arthritis. More studies are required to comprehend the underlying mechanisms of mitigating the EAM by B. subtilis NMCC-path-14.

In vivo evaluation of efficacy and safety of Coagulansin-A in treating arthritis

The current study aimed to determine the safety and efficacy of Coag-A through in vivo analysis in CFA induced mice model. Treatment of CFA induced arthritis in mice with Coagulansin-A (10 mg/kg i.p. daily for 28 days), a withanolide obtained from Withania coagulans, as well as standard drug treatment with Dexamethasone (5 mg/kg i.p) was provided. The effect of Coag-A on body weight, relative organ weight, hematology, serum biochemistry, survival rate, oxidative stress markers, and antioxidant enzymes was evaluated. The liver and kidney histopathology were also assessed to ascertain its safety profile. Treatment of arthritic mice with Coag-A considerably improved body weight, relative organ weight of liver, kidney, and spleen, ameliorated hematology and serum biochemistry, and increased survival and antioxidant potential. Coag-A was found to be safer with fewer adverse effects showing hepato-protective, nephroprotective, and anti-inflammatory effect. It also significantly (p < 0.001) improved histopathology of CFA-induced mice when compared with Dexa. In conclusion, compared to dexamethasone, Coag-A has demonstrated a greater therapeutic benefit and fewer side effects in the treatment of arthritis against the CFA-induced model.

Effects of Selenium Supplementation on the Indices of Disease Activity, Inflammation and Oxidative Stress in Patients with Rheumatoid Arthritis: a Randomized Clinical Trial

The aim of study was to evaluate the effect of selenium supplementation on disease activity, inflammation, and oxidative stress in patients with rheumatoid arthritis (RA). This study was a randomized double-blind placebo-controlled trial on 59 patients with RA. Participants were randomly divided to receive 200 μg/day of selenium or a placebo for 12 weeks. The disease activity score (DAS.CRP and DAS.ESR), erythrocyte sedimentation rate (ESR), serum levels of C-reactive protein (CRP), fasting blood glucose, lipids, antibodies to cyclic citrullinated protein (anti-CCP), nitric oxide, glutathione, and total antioxidant capacity were assessed. The mean of DAS.CRP and DAS.ESR decreased significantly within both study groups after the intervention. However, the between-group comparisons revealed no significant differences. The CRP levels decreased significantly in the selenium group, and this decrease was near the significance level compared to the placebo (P = 0.05). However, after adjusting for baseline values, the observed difference between groups did not remain significant. In addition, the values of ESR and anti-CCP decreased significantly within the selenium group. Although, between-group comparison did not statistically significant, the change in ESR and anti-CCP in the selenium group was small clinically relevant compared to the placebo [the effect size (95% CI) for ESR: 0.38 (- 0.14, 0.89), and for anti-CCP: 0.32 (- 0.2, 0.83)]. Our study showed that selenium caused a small clinically relevant improvement in some RA biomarkers such as ESR and anti-CCP. Future studies that evaluate the effects of novel forms of supplements such as selenium nanoparticles on the clinical symptoms and biomarkers of RA are suggested. Trial Registration: At www.irct.ir as IRCT20190924044869N1 on 2020-06-14.

Quantum Sensing for Real-Time Monitoring of Drug Efficacy in Synovial Fluid from Arthritis Patients

Diamond-based T1 relaxometry is a new technique that allows nanoscale magnetic resonance measurements. Here we present its first application in patient samples. More specifically, we demonstrate that relaxometry can determine the free radical load in samples from arthritis patients. We found that we can clearly differentiate between osteoarthritis and rheumatoid arthritis patients in both the synovial fluid itself and cells derived from it. Furthermore, we tested how synovial fluid and its cells respond to piroxicam, a common nonsteroidal anti-inflammatory drug (NSAID). It is known that this drug leads to a reduction in reactive oxygen species production in fibroblast-like synoviocytes (FLS). Here, we investigated the formation of free radicals specifically. While FLS from osteoarthritis patients showed a drastic decrease in the free radical load, cells from rheumatoid arthritis retained a similar radical load after treatment. This offers a possible explanation for why piroxicam is more beneficial for patients with osteoarthritis than those with rheumatoid arthritis.

The Influence of Diet and Physical Activity on Oxidative Stress in Romanian Females with Osteoarthritis

Osteoarthritis (OA) is the most prevalent chronic joint disease, increases in prevalence with age, and affects most individuals over 65. The present study aimed to assess the oxidative status in relation to diet and physical activity in patients with OA. We used a cross-sectional study applied to 98 females with OA. Blood samples were collected to determine oxidative stress markers: malonyl dialdehyde (MDA), reduced glutathione (GSH), oxidized glutathione (GSSG), and GSH/GSSG. Diet was estimated with a standardized food frequency questionnaire. We used the International Physical Activity Questionnaire (IPAQ) to assess the females’ physical activity. Multiple regression analyses were executed to determine the association between the oxidative markers and the intake of vegetables and fruit. The study showed that most patients were overweight or obese (88.8%). The level of physical activity was above the recommended level for adults, mainly based on household activities. The intake of vegetables and fruit was low. The MDA marker was inversely, statistically significantly associated with the consumption of vegetables (p < 0.05). Public health policies must address modifiable risk factors to reduce energy intake and obesity and increase the intake of vegetables and fruit. Higher consumption of vegetables and fruit may provide natural antioxidants that can balance oxidative compounds.

Therapeutic Potential of Standardized Extract of Melilotus indicus (L.) All. and Its Phytochemicals against Skin Cancer in Animal Model: In Vitro, In Vivo, and In Silico Studies

Melilotus indicus (L.) All. is known to have anti-inflammatory and anticancer properties. The present study explored the in vivo skin carcinogenesis attenuating potential of ethanolic extract of M. indicus (L.) All. (Miet) in a 7,12-dimethylbenz[a]anthracene (DMBA)-induced skin cancer model. The ethanolic extract of the plant was prepared by a maceration method. HPLC analysis indicated the presence of quercetin in abundance and also various other phytoconstituents. DPPH radical scavenging assay results showed moderate antioxidant potential (IC50 = 93.55 ± 5.59 μg/mL). A topical acute skin irritation study showed the nonirritant nature of Miet. Data for the skin carcinogenic model showed marked improvement in skin architecture in Miet and its primary phytochemicals (quercetin and coumarin) treated groups. Miet 50% showed comparable effects with 5-fluorouracil. Significant (p < 0.05) anticancerous effects were seen in coumarin-quercetin combination-treated animals than in single agent (coumarin and quercetin alone)-treated animals. Chorioallantoic membrane (CAM) assay results showed the antiangiogenic potential of Miet. Treatment with Miet significantly down-regulated the serum levels of CEA (carcinoembryonic antigen) and TNF-α (Tumor necrosis factor-α). Data for the docking study indicated the binding potential of quercetin and coumarin with TNF-α, EGFR, VEGF, and BCL2 proteins. Thus, it is concluded that Miet has skin cancer attenuating potential that is proposed to be due to the synergistic actions of its bioactive molecules. Further studies to explore the effects of Miet and its bioactive molecules as an adjuvant therapy with low dose anticancer drugs are warranted, which may lead to a new area of research.

Cardiovascular Drugs and Osteoarthritis: Effects of Targeting Ion Channels

Osteoarthritis (OA) and cardiovascular diseases (CVD) share many similar features, including similar risk factors and molecular mechanisms. A great number of cardiovascular drugs act via different ion channels and change ion balance, thus modulating cell metabolism, osmotic responses, turnover of cartilage extracellular matrix and inflammation. These drugs are consumed by patients with CVD for many years; however, information about their effects on the joint tissues has not been fully clarified. Nevertheless, it is becoming increasingly likely that different cardiovascular drugs may have an impact on articular tissues in OA. Here, we discuss the potential effects of direct and indirect ion channel modulating drugs, including inhibitors of voltage gated calcium and sodium channels, hyperpolarization-activated cyclic nucleotide-gated channels, β-adrenoreceptor inhibitors and angiotensin-aldosterone system affecting drugs. The aim of this review was to summarize the information about activities of cardiovascular drugs on cartilage and subchondral bone and to discuss their possible consequences on the progression of OA, focusing on the modulation of ion channels in chondrocytes and other joint cells, pain control and regulation of inflammation. The implication of cardiovascular drug consumption in aetiopathogenesis of OA should be considered when prescribing ion channel modulators, particularly in long-term therapy protocols.

Cissus quadrangularis (veldt grape) attenuates disease progression and anatomical changes in mono sodium iodoacetate (MIA)-induced knee osteoarthritis in the rat model

The Cissus quadrangularis (CQ) stem has interesting nutritional and pharmacological properties to promote the health of the skeletal system. It is a well-recognized plant in the conventional system of medicine in India for treating bone and joint-associated complications. This study focuses on identifying the active constituents from the stem and root extracts of CQ and validating its anti-osteoarthritic activity by the in vivo model. Notable levels of phenolics and flavonoids were found in the ethanol extracts of both CQ stem (CQSE) and root (CQRE), among other solvent fractions. UPLC-MS/MS analysis of these selective extracts resulted in different classes of active compounds from both positive and negative ionization modes. By analyzing their mass spectra and fragmentation pattern, 25 active compounds were identified. The CQSE and CQRE extracts, along with the standard drug (naproxen), were further tested in mono-sodium iodoacetate-induced experimental OA animals. The modulatory effects of the test extracts were assessed by haematology, synovial and cartilage marker profiling, radiology and histopathological analysis. The in vivo findings from the biochemical and physiological studies have led to the conclusion that the CQSE extract is a good choice for the management of OA. The results were substantially better than CQ root extract and naproxen drug-treated groups. Thus, CQS has bioactive constituents, which could facilitate recovery from joint tissue damage, cellular metabolism and associated risk factors attributable to dysfunctions in OA incidence and progression.

Associations between Coenzyme Q10 Status, Oxidative Stress, and Muscle Strength and Endurance in Patients with Osteoarthritis

Osteoarthritis (OA) causes oxidative stress. Coenzyme Q10 is an antioxidant that participates in energy production in the human body. The purpose of this study was to investigate the relationships among coenzyme Q10 status, oxidative stress, antioxidant capacity, and muscle function in patients with OA. This case-control study recruited 100 patients with OA and 100 without OA. The coenzyme Q10 status, oxidative stress, antioxidant capacity, muscle mass (by dual-energy X-ray absorptiometry), muscle strength (hand-grip and leg-back strength), and muscle endurance (dumbbell curls, gait speed, chair-stand test, and short physical performance battery) were measured. The results showed that both OA and elderly subjects had a low coenzyme Q10 status (<0.5 μM). Oxidative stress was significantly negatively correlated with muscle function (protein carbonyl, p < 0.05). Coenzyme Q10 level was positively associated with antioxidant capacity, muscle mass, muscle strength and muscle endurance in patients with OA (p < 0.05). Since OA is an age-related disease, coenzyme Q10 may be consumed by oxidative stress and thereby affect muscle function. Raising coenzyme Q10 in patients with OA could be suggested, which may benefit their antioxidant capacity and muscle function.

Pharmacodynamics of malondialdehyde as indirect oxidative stress marker after arrested-heart cardiopulmonary bypass surgery

BACKGROUND

An unavoidable consequence of cardiac surgery is oxidative stress and resulting peroxidation of biological molecules, in particular unsaturated lipids. The detection of peroxidation metabolites in biological environments is difficult due to their large variety, small concentration, and high reactivity. One of the most studied lipid peroxidation products is malondialdehyde and as such an important marker of oxidative stress. The aim of this study was to monitor the perioperative serum concentration of malondialdehyde as an oxidative stress marker in patients undergoing arrested-heart cardiopulmonary bypass surgery.

METHODS

This observational study was performed on 40 patients scheduled for on-pump arrested-heart open-heart surgery. Blood samples for the analysis of serum malondialdehyde were obtained preoperatively and intraoperatively immediately after the aortic clamp was removed. Afterwards, samples were obtained 12, 24, 48 and 72 h postoperatively. A gas chromatography-mass spectrometry analytical method was used to detect serum concentrations of malondialdehyde.

RESULTS

A significant increase in serum malondialdehyde concentration was detected at the time of aortic declamping. The malondialdehyde serum concentration continued to increase and peaked 12 h postoperatively. Afterwards it started to decline, but remained significantly higher compared to preoperative values both at 24 and 48 h postoperatively.

CONCLUSION

In contrast to some previous studies, our results demonstrate that in this patient population, the malondialdehyde levels do not peak at the end of the surgery, but continue to rise a few hours after surgery. Our findings indicate that in this patient population, oxidative stress with consequent lipid peroxidation is maintained and is even attenuated in the early postoperative period. This study was registered with the ISRCTN Registry under the trial registration number ISRCTN98572043.

General, 21-Day Postoperative Rehabilitation Program Has Beneficial Effect on Oxidative Stress Markers in Patients after Total Hip or Knee Replacement

Imbalance in prooxidant-antioxidant equilibrium plays an important role in the progression of osteoarthritis (OA). Postoperative rehabilitation significantly improves the functional activity of patients with OA. We aimed to assess the effect of the general 21-day postoperative rehabilitation on the oxidative stress markers in patients after total hip arthroplasty or knee replacement. Patients (n =41) started individually designed postoperative rehabilitation ca. 90 days after endoprosthesis implantation. We used the six-minute walk test (6MWT) to quantify the changes in their exercise capacity. We analyzed the oxidative stress markers: total antioxidant capacity (TAC), total superoxide dismutase (SOD), Cu-Zn-superoxide dismutase (CuZnSOD) and ceruloplasmin (Cp) activity, malondialdehyde (MDA) and lipofuscin (LPS) concentration in patients serum to asses changes in the oxidative stress intensity. We found that after 21-days postoperative rehabilitation program: the average distance walked by patients increased by 69 m; TAC increased by 0.20 ± 0.14 mmol/l; both SOD isoforms activities increased by 1.6 (±1.7) and 1.72 (±1.5) NU/ml, respectively; but Cp activity decreased by 1.8 (0.7-3.7) mg/dl. Also, we observed lower concentrations of lipid peroxidation markers: by 19.6 ± 24.4 μmol/l for MDA and by 0.4 ± 0.5 RF for LPS. A 21-day postoperative rehabilitation program effectively reduces oxidative processes, which helps the patients after total hip or knee replacement in a successful recovery.

Evaluation of plasma trace elements and oxidant/antioxidant status in Boerboel dogs with hip dysplasia

Changes in plasma concentrations of trace elements and oxidants/antioxidants were evaluated in twenty healthy Boerboels of both sexes and median age of 2 years. Antero-posterior and flexed lateral radiographs of the hip were obtained using digital x-ray machine and hip grading was done according to Fédération Cynologique Internationale (FCI) system. Blood was collected from the cephalic vein for determination of plasma concentrations of manganese (Mn), magnesium (Mg), copper (Cu), cobalt (Co), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPX) and Vitamin E. Correlation between the parameters was done using Pearson’s correlation. Eleven (11/20) of the Boerboel dogs had hip dysplasia (HD), comprising five (5/9) males and six (6/11) females. Plasma Mn, Cu and Co were insignificantly higher in Boerboels with normal hips than those with HD. MDA concentration was significantly (p<0.05) lower in Boerboels with normal hips (0.75 ± 0.84 µmol/L) than in dogs with HD (1.77 ± 0.78 µmol/L), while SOD was significantly (p<0.05) higher in Boerboels with normal hips (0.65 ± 0.22 U/ml) than with HD (0.32 ± 0.16 U/ml). It was concluded that there were differences in plasma oxidants/antioxidants between Boerboel dogs with normal hips and those with hip dysplasia suggesting their role in the pathogenesis of canine hip dysplasia

Effect of Boron on the Repair of Osteochondral Defect and Oxidative Stress in Rats: an Experimental Study

The aim of this study was to investigate the effect of boron on the repair of osteochondral defect and also on some antioxidant and oxidant parameters of both cartilage tissue and blood. A total of 24 adult male Wistar rats weighing between 350 and 400 g were used in the study. Animals were randomly divided into control (n = 8), boron (n = 8) and hyaluronic acid (HA) groups (n = 8). Under general anesthesia, a cylindrical full-thickness osteochondral defect 1.5 mm in diameter and 2 mm in depth was formed using a drill on the anterior side of the articular surface of the femur condyle. Boron group received 0.1 ml (10 mg/kg) of boron and HA group received 0.1 ml of HA, whereas control group received 0.1 ml of physiological saline solution. All agents administered intraarticular route and once a week for four times. At the end of the third month, the animals were euthanized and blood and joint tissue malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and catalase levels were measured. Defected femoral condyles of the rats were removed for a histopathological examination. Histopathology revealed that the total cartilage repair score of the HA group was better than those detected in boron and control groups. Blood and articular cartilage GSH, SOD, and catalase levels were higher in the boron and HA groups as compared to the control group, while MDA level was lower compared to the control group. In conclusion, it was suggested that boron was not as effective as HA in the repair of osteochondral defect, but its antioxidant property was superior to HA.

Negative effects of high mechanical tensile strain stimulation on chondrocyte injury in vitro

The mechanism underlying the development of osteoarthritis induced by high tensile strain is unclear. In this study, the effects of different degrees of mechanical tensile strain stimulation on Sprague-Dawley rat chondrocytes were explored. Rat chondrocytes were subjected to mechanical tensile strain at different intensities and frequencies (control group, low tensile strain group, intermediate tensile strain group, and high tensile strain group) using a self-made in vitro tensile strain device. After applying mechanical tensile strain, chondrocytes were collected to detect the expression of collagen II, Aggrecan, matrix metalloproteinase 13 (MMP13), ADAMTS5, and uncoupling protein 2 (UCP2) by real-time quantitative PCR and western blotting as well as reactive oxygen species (ROS) by fluorescence probes. Mechanical tensile strain at different frequencies and intensities had different effects on the biological functions of chondrocytes. Compared with the control group, the expression levels of Col II and Aggrecan in the low and intermediate tensile strain groups increased significantly, while the expression of MMP13 and ADAMTS5 decreased. There were no significant differences between the low and intermediate tensile strain groups. Col II and Aggrecan levels were significantly lower in the high tensile strain group than in the control group, while MMP13 and ADAMTS5 levels were higher. There were no significant differences in ROS production between the low and intermediate tensile strain groups and the control group, but the high tensile strain group exhibited significantly increased ROS production. The expression of UCP2 was significantly lower in the high tensile strain group than in all other groups. These results showed that stimulation with different levels of mechanical tensile strain has different effects on chondrocytes. Repeated high tensile strain promoted the anabolic function of chondrocytes, increased ROS production, and decreased UCP2. These results provide a potential mechanism by which osteoarthritis is induced by high mechanical tensile strain.

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.

Metabolic syndrome and the decreased levels of uric acid by leflunomide favor redox imbalance in patients with rheumatoid arthritis

Oxidative stress plays a role in the pathophysiology of rheumatoid arthritis (RA). The aim of the present study was to verify the influence of metabolic syndrome (MetS) and disease-modifying antirheumatic drugs on nitrosative and oxidative biomarkers in patients with RA. A total of 177 patients with RA and 150 healthy volunteers participated in this study, which measured lipid hydroperoxides, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), carbonyl protein, total radical-trapping antioxidant parameter (TRAP), uric acid (UA), and C-reactive protein (CRP). NOx and the NOx/TRAP ratio were significantly increased in RA, while no significant differences in lipid hydroperoxides, AOPP, UA, and TRAP levels were found between both groups. Treatment with leflunomide was associated with increased levels of carbonyl protein, and lowered levels in TRAP and UA, while the NOx/TRAP ratio further increased. NOx and the NOx/TRAP ratio were significantly higher in women than in men, while TRAP and UA were significantly lower in women. MetS was accompanied by increased AOPP and UA levels. RA was best predicted by increased NOx/TRAP ratio, CRP, and BMI. In conclusion, our data demonstrated that NOx and NOx/TRAP are strongly associated with RA physiopathology. Our findings suggest that inhibition of iNOS may become an interesting therapeutic approach for the treatment of RA. In addition, the presence of MetS and a decrease in levels of UA by leflunomide favor redox imbalance in RA patients. More studies are needed to evaluate the impact of antioxidant capacity reduction on RA progression.

Global and targeted metabolomics of synovial fluid discovers special osteoarthritis metabolites

To identify special metabolites in synovial fluid of osteoarthritis (OA) via a metabolomics approach. Synovial fluid of 35 participants (25 OA patients and 10 controls) was detected by GC-TOF/MS and multivariate data analysis was applied to analyze correlation among the observations. Different metabolites were screened by VIP value (VIP > 1), student t-test (p < 0.05), and fold change (fold >1.5), and verified with the standard metabolites in the synovial fluid of 24 OA patients and 11 controls by LC/MS. The classification performance of different metabolites was analyzed by receiver operating characteristic (ROC) analysis. The results showed that six different metabolites (glutamine, 1,5-anhydroglucitol, gluconic lactone, tyramine, threonine, and 8-aminocaprylic acid) were strongly associated with OA in global metabolomics. Verified results of the first three metabolites were the same as the identified results using targeted metabolomics. ROC curve analysis demonstrated that their concentrations in synovial fluid were strongly correlated to OA. In addition, the concentrations of gluconic lactone were significantly different between OA and RA. Metabolites with altered levels may be contributors to OA pathogenesis and can be used as potential diagnosis criteria for OA. Gluconic lactone may prove to be a novel criterion for differential diagnosis of OA from RA. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1973-1981, 2017.

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.

The onset of lipid peroxidation in rheumatoid arthritis: consequences and monitoring

Several epidemiological studies propose the association of rheumatoid arthritis (RA) with oxidative stress. The aim of this study was to estimate the possible onset of systemic lipid peroxidation in RA patients and its relevance for pathophysiology and monitoring of RA. Seventy-three patients with RA and 73 healthy subjects were included in the study. Lipid peroxidation was estimated by the measurement of 4-hydroxynonenal (4-HNE), 4-hydroxyhexenal, malondialdehyde, acrolein, crotonaldehyde, 4-oxononenal, and isoprostanes (8-isoPGF(2α)) levels. Cytosolic phospholipase A(2) (cPLA(2)), platelet-activating factor acetylhydrolase (PAF-AH) and glutathione peroxidase (GSH-Px) activities and vitamin E levels were also determined. In parallel, the plasma levels of phospholipid arachidonic acid (AA), linoleic acid (LA), and 4-HNE-protein adducts were monitored. Plasma of RA patients had increased vitamin E levels, but decreased GSH-Px activity and phospholipid AA and LA levels when compared to levels of the healthy subjects. The levels of aldehydes were significantly increased in the plasma of the RA patients and even more in urine. Significant increases in HNE-modified protein adducts was observed for the first time in plasma of RA patients, while the activities of PAF-AH and cPLA(2) were decreased. The 8-isoPGF(2α) levels were 9-fold higher in plasma and 3-fold higher in urine of RA patients and were related to the severity of disease. The levels of lipid peroxidation products in plasma and in urine suggest the relationship between lipid peroxidation and the development of RA. Additionally, urine 8-isoPGF(2α), plasma 4-HNE and 4-HNE-protein adducts appear to be convenient biomarkers to monitor progression of this autoimmune disease.

Anti-inflammatory and antiarthritic activity of anthraquinone derivatives in rodents

Aloe emodin is isolated compound of aloe vera which is used traditionally as an anti-inflammatory agent. In vitro pharmacokinetic data suggest that glucuronosyl or sulfated forms of aloe emodin may provide some limitations in its absorption capacity. Aloe emodin was reported to have in vitro anti-inflammatory activity due to inhibition of inducible nitric oxide (iNO) and prostaglandin E2, via its action on murine macrophages. However, present work evidenced that molecular docking of aloe emodin modulates the anti-inflammatory activity, as well as expression of COX-2 (cyclooxygenase-2) in rodent. The AEC (4,5-dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2 carboxylic acid) was synthesized using aloe emodin as starting material. The study was planned for evaluation of possible anti-inflammatory and antiarthritic activity in carrageenan rat induced paw oedema and complete Freund's adjuvant induced arthritis in rats. The AE (aloe emodin) and AEC significantly (P < 0.001) reduced carrageenan induced paw edema at 50 and 75 mg/kg. Complete Freund's adjuvant induced arthritis model showed significant (P < 0.001) decrease in injected and noninjected paw volume, arthritic score. AE and AEC showed significant effect on various biochemical, antioxidant, and hematological parameters. Diclofenac sodium 10 mg/kg showed significant (P < 0.001) inhibition in inflammation and arthritis.