Oxidative changes in the blood and serum albumin differentiate rats with monoarthritis and polyarthritis

Effects of resveratrol on rheumatic symptoms and hepatic metabolism of arthritic rats

OBJECTIVES

Resveratrol has been studied as a potential agent for treating rheumatic conditions; however, this compound suppresses glucose synthesis and glycogen catabolism when infused in perfused livers of both arthritic and healthy rats. This study investigated the effects of oral administration of resveratrol on inflammation and liver metabolism in rats with arthritis induced by Freund's adjuvant, which serves as rheumatoid arthritis model.

METHODS

Holtzman rats, both healthy and exhibiting arthritic symptoms, were orally treated with resveratrol at doses varying from 25 to 500 mg/kg for a 5-day period preceding arthritis induction, followed by an additional 20-day period thereafter. Paw edema, arthritic score and hepatic myeloperoxidase activity were assessed to evaluate inflammation. Glycogen catabolism and gluconeogenesis from lactate were respectively evaluated in perfused livers from fed and fasted rats.

RESULTS

Resveratrol decreased the liver myeloperoxidase activity at doses above 100 mg/kg, and decreased the paw edema and delayed the arthritic score at doses above 250 mg/kg. The hepatic gluconeogenesis was decreased in arthritic rats and resveratrol did not improve it. However, resveratrol did not negatively modify the gluconeogenesis in livers of healthy and arthritic rats. Glycogen catabolism was in part and slightly modified by resveratrol in the liver of arthritic and healthy rats.

CONCLUSIONS

It is improbable that resveratrol negatively affects the liver metabolism, especially considering that gluconeogenesis is highly fragile to changes in cellular architecture. The findings suggest that resveratrol could serve as alternative for treating rheumatoid arthritis. Nevertheless, prudence is advised regarding its transient effects on liver metabolism.

A comprehensive survey of warfarin-induced hepatic toxicity using histopathological, biomarker, and molecular evaluation

Warfarin finds human application as anticoagulant therapy. Warfarin usage can cause liver damage and hemorrhage. Besides functioning as anticoagulant and causing continuous bleeding of pests, the mechanism of toxicity of warfarin is unknown. In this study, Wild female and male rats were administrated orally with warfarin for 18 days at 9, 18, 27.5, and 55 mg/kg, respectively. Hepatoxicity was determined by assessing, LD50, leukocyte counts, immunochemistry, histopathology, serum proteins, Western blotting, especially of markers of liver injury, such as AST, ALT & ALP, and markers of antioxidant and oxidative stress markers. Warfarin treatment decreased Nrf2 levels while it increased caspase 3, CYP2C9, COLL1A1. It caused cellular damage and fibrosis of liver. The plasma levels of markers of liver injury, AST, ALT, ALP, bilirubin and transferrin were increased. The plasma levels of albumin, IgG and antitrypsin were decreased. Warfarin treatment decreased RBC and total lymphocyte count while increasing selectively neutrophils. Warfarin exposure caused increased oxidative stress; increased LPO and decreased GSH, SOD, CAT and NO production. Oral exposure of rats with Warfarin leads to increased oxidative stress resulting into liver damage via CYP2C9 mediated by Nrf2 depletion.

A Novel Hydroxyapatite/Vitamin B12 Nanoformula for Treatment of Bone Damage: Preparation, Characterization, and Anti-Arthritic, Anti-Inflammatory, and Antioxidant Activities in Chemically Induced Arthritic Rats

The usage of nanomaterials for rheumatoid arthritis (RA) treatment can improve bioavailability and enable selective targeting. The current study prepares and evaluates the in vivo biological effects of a novel hydroxyapatite/vitamin B₁₂ nanoformula in Complete Freund's adjuvant-induced arthritis in rats. The synthesized nanoformula was characterized using XRD, FTIR, BET analysis, HERTEM, SEM, particle size, and zeta potential. We synthesized pure HAP NPs with 71.01% loading weight percentages of Vit B12 and 49 mg/g loading capacity. Loading of vitamin B₁₂ on hydroxyapatite was modeled by Monte Carlo simulation. Anti-arthritic, anti-inflammatory, and antioxidant effects of the prepared nanoformula were assessed. Treated arthritic rats showed lower levels of RF and CRP, IL-1β, TNF-α, IL-17, and ADAMTS-5, but higher IL-4 and TIMP-3 levels. In addition, the prepared nanoformula increased GSH content and GST antioxidant activity while decreasing LPO levels. Furthermore, it reduced the expression of TGF-β mRNA. Histopathological examinations revealed an improvement in joint injuries through the reduction of inflammatory cell infiltration, cartilage deterioration, and bone damage caused by Complete Freund's adjuvant. These findings indicate that the anti-arthritic, antioxidant, and anti-inflammatory properties of the prepared nanoformula could be useful for the development of new anti-arthritic treatments.

The protective effect of green tea on diabetes-induced hepato-renal pathological changes: a histological and biochemical study

We investigated the protective effect of green tea on diabetic hepato-renal complications. Thirty male Wistar rats were randomly divided into five equal groups: normal control, diabetic control, glibenclamide-treated, green tea-treated, and combined therapy-treated groups; ethical approval number "BERC-014-01-20." After eight weeks, animals were sacrificed by CO₂ euthanasia method, liver and kidney tissues were processed and stained for pathological changes, and blood samples were collected for biochemical analysis. Diabetic rats showed multiple hepato-renal morphological and apoptotic changes associated with significantly increased some biochemical parameters, while serum albumin and HDL decreased significantly compared to normal control (p < .05). Monotherapy can induce significant improvements in pathological and biochemical changes but has not been able to achieve normal patterns. In conclusion, green tea alone has a poor hypoglycaemic effect but can reduce diabetic complications, whereas glibenclamide cannot prevent diabetic complications. The addition of green tea to oral hypoglycaemic therapy has shown a potent synergistic effect.

Resveratrol biotransformation and actions on the liver metabolism of healthy and arthritic rats

AIMS

To investigate the effects of resveratrol on glycogen catabolism and gluconeogenesis in perfused livers of healthy and arthritic rats. The actions of resveratrol-3-O-glucuronide (R3G) and the biotransformation of resveratrol into R3G was further evaluated in the livers.

MAIN METHODS

arthritis was induced with Freund's adjuvant. Resveratrol at concentrations of 10, 25, 50, 100 and 200 μM and 200 μM R3G were introduced in perfused livers. Resveratrol and metabolites were measured in the outflowing perfusate. Respiration of isolated mitochondria and activity of gluconeogenic enzymes were also evaluated in the livers.

KEY FINDINGS

resveratrol inhibited glycogen catabolism when infused at concentrations above 50 μM and gluconeogenesis even at 10 μM in both healthy and arthritic rat livers, but more sensitive in these latter. Resveratrol above 100 μM inhibited ADP-stimulated respiration and the activities of NADH- and succinate-oxidases in mitochondria, which were partially responsible for gluconeogenesis inhibition. Pyruvate carboxylase activity was inhibited by 25 μM resveratrol and should inhibit gluconeogenesis already at low concentrations. Resveratrol was significantly metabolized to R3G in healthy rat livers, however, R3G formation was lower in arthritic rat livers. The latter must be in part a consequence of a lower glucose disposal for glucuronidation. When compared to resveratrol, R3G inhibited gluconeogenesis in a lower extension and glycogen catabolism in a higher extension.

SIGNIFICANCE

the effects of resveratrol and R3G tended to be transitory and existed only when the resveratrol is present in the organ, however, they should be considered because significant serum concentrations of both are found after oral ingestion of resveratrol.

Concerted regulation of OPG/RANKL/ NF‑κB/MMP-13 trajectories contribute to ameliorative capability of prodigiosin and/or low dose γ-radiation against adjuvant- induced arthritis in rats

BACKGROUND

Prodigiosin (PDG) is a microbial red dye with antioxidant and anti-inflammatory properties, although its effect on rheumatoid arthritis (RA) remains uncertain. Also, multiple doses of low dose γ- radiation (LDR) have been observed to be as a successful intervention for RA. Thus, the purpose of this study was to investigate the ameliorative potential of PDG and/or LDR on adjuvant-induced arthritis (AIA) in rats.

METHODS

The anti-inflammatory and anti-arthritic effects of PDG and/or LDR were examined in vitro and in vivo, respectively. In the AIA model, the arthritic indexes, paw swelling degrees, body weight gain, and histopathological assessment in AIA rats were assayed. The impact of PDG (200 µg/kg; p.o) and/or LDR (0.5 Gy) on the levels of pro- and anti-inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-18, IL-17A, and IL-10) as well as the regulation of osteoprotegrin (OPG)/ receptor activator of nuclear factor κB ligand (RANKL)/ nuclear factor-κB (NF-κB)/MMP-13 pathways was determined. Methotrexate (MTX; 0.05 mg/kg; twice/week, i.p) was administered concurrently as a standard anti-arthritic drug.

RESULTS

PDG and/or LDR markedly diminished the arthritic indexes, paw edema, weigh loss in AIA rats, alleviated the pathological alterations in joints, reduced the levels of pro-inflammatory cytokines IL-1β, TNF-α, IL-6, IL-18, IL-17A, and RANKL in serum and synovial tissues, while increasing anti-inflammatory cytokines IL-10 and OPG levels. Moreover, PDG and/or LDR down-regulated the expression of RANKL, NF-κBp65, MMP13, caspase-3, and decreased the RANKL/OPG ratio, whereas OPG and collagen II were enhanced in synovial tissues.

CONCLUSION

PDG and/or LDR exhibited obvious anti-RA activity on AIA.

Strenuous swimming raises blood non-enzymatic antioxidant capacity in rats

The non-enzymatic antioxidant system protects blood components from oxidative damage and/or injury. Herein, plasma non-enzymatic antioxidant capacity after acute strenuous swimming exercise (Exe) and exercise until exhaustion (Exh) was measured in rats. The experiments were carried out in never exposed (Nex) and pre-exposed (Pex) groups. The Nex group did not undergo any previous training before the acute strenuous swimming test and the Pex group was submitted to daily swimming for 10 min in the first week and 15 min per day in the second week before testing. Plasma glucose, lactate, and pyruvate were measured and plasma total protein sulfhydryl groups (thiol), trolox equivalent antioxidant capacity (TEAC), ferric reducing ability of plasma (FRAP), and total radical-trapping antioxidant parameter (TRAP) levels were evaluated. There were marked increases in plasma lactate concentrations (Nex-Control 1.31±0.20 vs NexExe 4.16±0.39 vs NexExh 7.19±0.67) and in thiol (Nex-Control 271.9±5.6 vs NexExh 314.7±5.7), TEAC (Nex-Control 786.4±60.2 vs NexExh 1027.7±58.2), FRAP (Nex-Control 309.2±17.7 vs NexExh 413.4±24.3), and TRAP (Nex-Control 0.50±0.15 vs NexExh 2.6±0.32) levels after acute swimming and/or exhaustion. Also, there were increased plasma lactate concentrations (Pex-Control 1.39±0.15 vs PexExe 5.22±0.91 vs PexExh 10.07±0.49), thiol (Pex-Control 252.9±8.2 vs PexExh 284.6±6.7), FRAP (Pex-Control 296.5±15.4 vs PexExh 445.7±45.6), and TRAP (Pex-Control 1.8±0.1 vs PexExh 4.6±0.2) levels after acute swimming and/or exhaustion. Lactate showed the highest percent of elevation in the Nex and Pex groups. In conclusion, plasma lactate may contribute to plasma antioxidant defenses, and the TRAP assay is the most sensitive assay for assessing plasma non-antioxidant capacity after strenuous exercise.

Alpha-tocopherol-loaded polycaprolactone nanoparticles improve the inflammation and systemic oxidative stress of arthritic rats

Background and aim

The present study investigated the effects of orally administered α-tocopherol-loaded polycaprolactone nanoparticles on the articular inflammation and systemic oxidative status of middle-aged Holtzman rats with Freund's adjuvant-induced polyarthritis, a model for rheumatoid arthritis. Intraperitoneally administered free α-tocopherol provided the reference for comparison.

Experimental procedure

Two protocols of treatment were followed: intraperitoneal administration of free α-tocopherol (100 mg/kg i.p.) or oral administration of free and nanoencapsulated α-tocopherol (100 mg/kg p.o.). Animals were treated during 18 days after arthritis induction.

Results

Free (i.p.) and encapsulated α-tocopherol decreased the hind paws edema, the leukocytes infiltration into femorotibial joints and the mRNA expression of pro-inflammatory cytokines in the tibial anterior muscle of arthritic rats, but the encapsulated compound was more effective. Free (i.p.) and encapsulated α-tocopherol decreased the high levels of reactive oxygen species in the brain and liver, but only the encapsulated compound decreased the levels of protein carbonyl groups in these organs. Both free (i.p.) and encapsulated α-tocopherol increased the α-tocopherol levels and the ratio of reduced to oxidized glutathione in these organs.

Conclusion

Both intraperitoneally administered free α-tocopherol and orally administered encapsulated α-tocopherol effectively improved inflammation and systemic oxidative stress in middle-aged arthritic rats. However, the encapsulated form should be preferred because the oral administration route does not be linked to the evident discomfort that is caused in general by injectable medicaments. Consequently, α-tocopherol-loaded polycaprolactone nanoparticles may be a promising adjuvant to the most current approaches aiming at rheumatoid arthritis therapy.

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Oxidative stress is systemically increased in rats with adjuvant-induced arthritis.

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Arthritic rats were orally treated with α-tocopherol-loaded polycaprolactone nanoparticles.

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Treatment decreased the paw edema and articular inflammation of arthritic rats.

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Treatment improved the oxidative stress in the liver and brain arthritic rats.

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The content of α-tocopherol was increased in the brain and liver of treated rats.

Mangiferin exert protective effects on joints of adjuvant-induced arthritis rats by regulating the MAPKs/NF-κB pathway of fibroblast-like synoviocytes

BACKGROUND

Mangiferin (MF) is a bioactive ingredient predominantly isolated from the mango tree, that has been reported to have antioxidant, anti-inflammatory, and immunomodulatory effects. This study was aimed to investigate the protective effect of MF on the joints of arthritic rats and explore the underlying mechanisms of this function.

METHODS

Adjuvant-induced arthritis (AA) rat model was established and clinical severity of AA was evaluated by arthritis index, paw edema, plasma, and synovium homogenate parameters. The severity of joint destruction was assessed by radiological and histopathological. Immunohistochemical analysis was employed to detect the protein expression of MMP-3, MMP-13 in synovium and cartilage tissues. The vitro effects of MF on proliferation, migration, apoptosis, and production of inflammatory mediators in RA- FLSs were determined by the CCK8 assay, transwell assay, flow cytometry, and real-time PCR, respectively.

RESULTS

The results demonstrated that MF treatment significantly alleviated arthritis index, paw swelling and decreased the secretion of inflammatory cytokines in plasma and synovium. Meanwhile, MF inhibited synovial inflammation, pannus formation, and bone erosion in AA rats. It also ameliorated the oxidative stress state of arthritic rats via modulating the level of MDA, SOD, CAT, GSH, NO. In addition, MF effectively attenuated the destructive behavior of RA-FLSs by inhibiting proliferation, migration, and secretion of inflammatory mediators, and promoting apoptosis. The further mechanistic analysis demonstrated that MF might exert an antiarthritic effect via inhibiting the pathway of MAPKs (ERK2 and p38) and NF-κ B.

CONCLUSION

Taken together, our results demonstrated that MF would be a promising anti-arthritic agent candidate for further research.

Low dose of quercetin-loaded pectin/casein microparticles reduces the oxidative stress in arthritic rats

AIMS

Quercetin has been investigated as an agent to treat rheumatoid arthritis. At high doses it improves inflammation and the antioxidant status of arthritic rats, but it also exerts mitochondriotoxic and pro-oxidant activities. Beneficial effects of quercetin have not been found at low doses because of its chemical instability and low bioavailability. In the hope of overcoming these problems this study investigated the effects of long-term administration of quercetin-loaded pectin/casein microparticles on the oxidative status of liver and brain of rats with adjuvant-induced arthritis.

MAIN METHODS

Particle morphology was viewed with transmission electron microscopy and the encapsulation efficiency was measured indirectly by X-ray diffraction. Quercetin microcapsules (10 mg/Kg) were orally administered to rats during 60 days. Inflammation indicators and oxidative stress markers were measured in addition to the respiratory activity and ROS production in isolated mitochondria.

KEY FINDINGS

Quercetin was efficiently encapsulated inside the polymeric matrix, forming a solid amorphous solution. The administration of quercetin microparticles to arthritic rats almost normalized protein carbonylation, lipid peroxidation, the levels of reactive oxygen species as well as the reduced glutathione content in both liver and brain. The paw edema in arthritic rats was not responsive, but the plasmatic activity of ALT and the mitochondrial respiration were not affected by quercetin, indicating absence of mitochondriotoxic or hepatotoxic actions.

SIGNIFICANCE

Quercetin-loaded pectin/casein microcapsules orally administered at a low dose improve oxidative stress of arthritic rats without a strong anti-inflammatory activity. This supports the long-term use of quercetin as an antioxidant agent to treat rheumatoid arthritis.

Protective effects of selenium on acrylamide-induced neurotoxicity and hepatotoxicity in rats

Objective(s):

Acrylamide (ACR), has wide uses in different industries. ACR induced several toxicities including neurotoxicity and hepatotoxicity. The probable protective effects of selenium on ACR-induced neurotoxicity and hepatotoxicity in rats were evaluated.

Materials and Methods:

Male Wistar rats were studied for 11 days in 8 groups: 1. Control, 2. ACR (50 mg/kg, IP), 3-5. ACR+ selenium (0.2, 0.4, 0.6 mg/kg, IP), 6. ACR+ the most effective dose of selenium (0.6 mg/kg, IP) three days after ACR administration, 7. ACR+ vitamin E (200 mg/kg IP, every other day) 8. Selenium (0.6 mg/kg IP). Finally, behavioral tests were done. The levels of malondialdehyde (MDA), glutathione (GSH), Bcl-2, Bax and caspase 3 proteins in liver and cerebral cortex tissues were measured. Also, the amount of albumin, total protein, alanine transaminase (ALT) and aspartate transaminase (AST) enzymes were determined in serum.

Results:

ACR caused the severe motor impairment, increased MDA level and decreased GSH content, enhanced Bax/Bcl-2 ratio and caspase 3 proteins in brain and liver tissues. Besides, the level of AST was elevated while the total serum protein and albumin levels were decreased. Administration of selenium (0.6 mg/kg) (from the first day of the experiment and the third day) significantly recovered locomotor disorders, increased GSH content, and reduced MDA level. Also, selenium decreased Bax/Bcl-2 ratio and caspase 3 levels in brain and liver tissues.

Conclusion:

The oxidative stress and apoptosis pathways have important roles in neurotoxicity and hepatotoxicity of ACR. Selenium significantly reduced ACR-induced toxicity through inhibition of oxidative stress and apoptosis.

Actions of multiple doses of resveratrol on oxidative and inflammatory markers in plasma and brain of healthy and arthritic rats

The actions of resveratrol in brain and plasma of rats with adjuvant-induced arthritis were investigated. Resveratrol was administered orally during a period of 23 days. A major concern of the present work was to explore an ample range of daily doses (10-200 mg/kg). Several oxidative and inflammatory markers were measured. Important effects of resveratrol treatment were the normalization of the plasma myeloperoxidase activity (inflammatory marker), the normalization of the brain xanthine oxidase activity (reactive oxygen species source) and the near-normalization of the catalase activity in the brain (antioxidant defence). These effects presented obvious dose dependencies in the range up to 200 mg/kg. Resveratrol also reduced protein and lipid damage within the lowest dose ranges investigated, and its action as a free radical scavenger activity was enhanced in brain mitochondria of arthritic rats. Resveratrol failed in restoring the diminished albumin levels and plasma protein thiols in arthritic rats. The latter, however, were substantially increased in healthy rats at low doses (up to 50 mg/kg), a sign of antioxidant action. This increase was reversed at higher doses, a sign of pro-oxidant action. The observations agree with the notion that low doses of resveratrol might be useful as an adjuvant to the conventional antirheumatic drugs.

The Role of Oxidative Stress in Physiopathology and Pharmacological Treatment with Pro- and Antioxidant Properties in Chronic Diseases

Oxidative stress (OS) has the ability to damage different molecules and cellular structures, altering the correct function of organs and systems. OS accumulates in the body by endogenous and exogenous mechanisms. Increasing evidence points to the involvement of OS in the physiopathology of various chronic diseases that require prolonged periods of pharmacological treatment. Long-term treatments may contribute to changes in systemic OS. In this review, we discuss the involvement of OS in the pathological mechanisms of some chronic diseases, the pro- or antioxidant effects of their pharmacological treatments, and possible adjuvant antioxidant alternatives. Diseases such as high blood pressure, arteriosclerosis, and diabetes mellitus contribute to the increased risk of cardiovascular disease. Antihypertensive, lipid-lowering, and hypoglycemic treatments help reduce the risk with an additional antioxidant benefit. Treatment with methotrexate in autoimmune systemic inflammatory diseases, such as rheumatoid arthritis, has a dual role in stimulating the production of OS and producing mitochondrial dysfunction. However, it can also help indirectly decrease the systemic OS induced by inflammation. Medicaments used to treat neurodegenerative diseases tend to decrease the mechanisms related to the production of reactive oxygen species (ROS) and balance OS. On the other hand, immunosuppressive treatments used in cancer or human immunodeficiency virus infection increase the production of ROS, causing significant oxidative damage in different organs and systems without widely documented exogenous antioxidant administration alternatives.

A Pilot Study to Evaluate the Effects of Oral N-Acetyl Cysteine on Inflammatory and Oxidative Stress Biomarkers in Rheumatoid Arthritis

BACKGROUND

Rheumatoid Arthritis (RA) is a common inflammatory disease of the joints. Due to the importance of inflammation and oxidative stress in the pathogenesis of RA, drugs that have anti-oxidant and anti-inflammatory properties, such as N-acetyl Cysteine (NAC), can be used as adjunctive therapy in patients with RA.

AIMS

The aim of this study was to evaluate the effects of oral NAC on inflammatory cytokines and oxidative stress in patients with RA.

METHODS

Adjunct to standard treatment, the NAC group (23 patients) received 600 mg of NAC twice daily and the placebo group (19 patients) received identical placebo twice daily for 12 weeks. Serum levels of Total Oxidant Status (TOS), Total Antioxidant Capacity (TAC), nitric oxide (NO), Total Thiol Groups (TTG), Malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), interleukin- 6 (IL-6), C-reactive Protein (CRP), and Erythrocyte Sedimentation Rate (ESR) were measured at baseline and at the end of the study.

RESULTS

Results showed that in the NAC group, the serum levels of MDA, NO, IL-6, TNF-α, ESR and CRP were significantly lower than the baseline. Also, the serum level of TAC and TTG, as antioxidant parameters, increased significantly. However, only NO, MDA and TTG showed a significant difference in the NAC group as compared to the placebo group at the end of study.

CONCLUSION

According to the results of this study, oral NAC can significantly reduce the several oxidative stress factors and inflammatory cytokines. These results need to be confirmed in larger studies while considering clinical outcomes of RA patients.

Methyl Jasmonate Reduces Inflammation and Oxidative Stress in the Brain of Arthritic Rats

Methyl jasmonate (MeJA), common in the plant kingdom, is capable of reducing articular and hepatic inflammation and oxidative stress in adjuvant-induced arthritic rats. This study investigated the actions of orally administered MeJA (75–300 mg/kg) on inflammation, oxidative stress and selected enzyme activities in the brain of Holtzman rats with adjuvant-induced arthritis. MeJA prevented the arthritis-induced increased levels of nitrites, nitrates, lipid peroxides, protein carbonyls and reactive oxygen species (ROS). It also prevented the enhanced activities of myeloperoxidase and xanthine oxidase. Conversely, the diminished catalase and superoxide dismutase activities and glutathione (GSH) levels caused by arthritis were totally or partially prevented. Furthermore, MeJA increased the activity of the mitochondrial isocitrate dehydrogenase, which helps to supply NADPH for the mitochondrial glutathione cycle, possibly contributing to the partial recovery of the GSH/oxidized glutathione (GSSG) ratio. These positive actions on the antioxidant defenses may counterbalance the effects of MeJA as enhancer of ROS production in the mitochondrial respiratory chain. A negative effect of MeJA is the detachment of hexokinase from the mitochondria, which can potentially impair glucose phosphorylation and metabolism. In overall terms, however, it can be concluded that MeJA attenuates to a considerable extent the negative effects caused by arthritis in terms of inflammation and oxidative stress.

Modulator role of infliximab and methotrexate through the transient receptor potential melastatin 2 (TRPM2) channel in neutrophils of patients with rheumatoid arthritis: a pilot study

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory disease causing symmetric polyarthritis. In this study, we aimed to investigate the effects of infliximab (INF) and methotrexate (MTX) on apoptosis, oxidative stress, and calcium signaling in the neutrophils of RA patients.

MATERIAL AND METHODS

Neutrophils were isolated from 10 patients with newly diagnosed RA and 10 healthy controls. They were divided into four groups (control, RA, RA + MTX, RA + INF) and incubated with MTX and INF. In the cell viability (MTT) test, the ideal non-toxic dose and incubation time of MTX were found to be 0.1 mM and 1 h, respectively. The neutrophils were also incubated with the TRPM2 channel blocker N-(p-amylcinnamoyl) anthranilic acid (ACA).

RESULTS

Intracellular free Ca²⁺ concentration, intracellular reactive oxygen species (ROS) production, mitochondrial depolarization, lipid peroxidation, apoptosis, and caspase 3 and caspase 9 activities were found to be significantly higher in the neutrophils of RA patients compared to controls. MTT, reduced glutathione (GSH) level, and glutathione peroxidase (GSHPx) activity were significantly lower in the neutrophils of RA patients. However, MTT, GSH and GSHPx values were detected to be significantly increased with INF and MTX therapies. The Ca²⁺ concentrations were further decreased by the ACA therapy.

CONCLUSIONS

Our results suggest that INF and MTX are useful antagonists in apoptosis and mitochondrial oxidative stress in the neutrophils of RA patients. INF and MTX decreased the Ca²⁺ concentration through inhibition of the TRPM2 channel in the neutrophils of RA patients. It may be a new pathway in the mechanisms of anti-rheumatic drugs.

A rapid method for measuring serum oxidized albumin in a rat model of proteinuria and hypertension

Oxidative stress is a risk for and cause of various disease, however, measurements of oxidative stress are either time-consuming or non-specific. Here, we established a rapid method of using high performance liquid chromatography (HPLC) to measure serum oxidized albumin in a rat model. We optimized HPLC conditions for rat oxidized albumin. To validate our method, three-week-old male Sprague-Dawley rats were uninephrectomized and treated normal diet, high salt diet or high salt diet with Tempol, a superoxide dismutase (SOD) mimetic. After 4 weeks of treatment, we analyzed serum oxidized albumin. The main findings are listed as below. (i) Our method of oxidized albumin measurement only takes 16 minutes, with an intra-day and inter-day deviation within 1% and a detection limit concentration of 6.4 mg/ml. (ii) Oxidized albumin levels were significantly higher in the high salt diet group than in the normal salt diet group, and this effect was reversed by Tempol. (iii) Oxidized albumin levels also correlated with urinary protein and 8-isoprostane levels. In conclusion, we have established a simple method for evaluating rat serum oxidized albumin using HPLC. Our method is rapid and has an advantage over conventional methods and may be useful for animal models of oxidative stress.

Yerba mate aqueous extract improves the oxidative and inflammatory states of rats with adjuvant-induced arthritis

Healthy and adjuvant-induced arthritic rats were treated for 23 days with daily doses of 400 and 800 mg kg⁻¹Ilex paraguariensisextract.

Quercetin, a Plant Polyphenol, Has Potential for the Prevention of Bone Destruction in Rheumatoid Arthritis

We investigated the immune-regulatory function of quercetin, in interleukin (IL)-17-produced osteoclastogenesis in rheumatoid arthritis (RA). RA fibroblasts-like synoviocytes (RA-FLS) were stimulated with IL-17, and the mRNA expression and secretion of receptor activator of nuclear factor kappa-B ligand (RANKL) were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. CD14⁺ monocytes (osteoclast precursors) were stimulated with IL-17, RANKL, with/without quercetin, and tartrate-resistant acid phosphatase activity was evaluated to assess osteoclast differentiation. Osteoclast differentiation was investigated after coculturing IL-17-stimulated RA-FLS and Th17 cells with monocytes. CD4⁺ T cells were cocultured with quercetin under Th17-inducing conditions, and their differentiation to Th17 cells and Treg cells was determined by flow cytometry analysis. We found that IL-17 stimulated RA-FLS to produce RANKL and quercetin decreased the IL-17-induced RANKL protein levels. Quercetin decreased the IL-17-produced activation of mammalian target of rapamycin, extracellular signal-regulated kinase and inhibitor of kappa B-alpha. When monocytes were stimulated with IL-17, macrophage colony-stimulating factor or RANKL, mature osteoclasts were formed, and quercetin decreased this osteoclastogenesis. When monocytes were cultured with IL-17-prestimulated RA-FLS or Th17 cells, osteoclasts were produced, and quercetin decreased this osteoclast differentiation. In Th17-differentiation conditions, quercetin suppressed Th17 cell and the production of IL-17, but quercetin did not affect Treg cells. Quercetin inhibits IL-17-stimulated RANKL production in RA-FLS and IL-17-stimulated osteoclast formation. Quercetin reduces Th17 differentiation. Quercetin could be an additional therapeutic option for bone destructive processes in RA.

Fatty acids uptake and oxidation are increased in the liver of rats with adjuvant-induced arthritis

Severe rheumatoid cachexia is associated with pronounced loss of muscle and fat mass in patients with advanced rheumatoid arthritis. This condition is associated with dyslipidemia and predisposition to cardiovascular diseases. Circulating levels of triglycerides (TG) and free fatty acids (FFA) have not yet been consistently defined in severe arthritis. Similarly, the metabolism of these lipids in the arthritic liver has not yet been clarified. Aiming at filling these gaps this study presents a characterization of the circulating lipid profile and of the fatty acids uptake and metabolism in perfused livers of rats with adjuvant-induced arthritis. The levels of TG and total cholesterol were reduced in both serum (10-20%) and liver (20-35%) of arthritic rats. The levels of circulating FFA were 40% higher in arthritic rats, possibly in consequence of cytokine-induced adipose tissue lipolysis. Hepatic uptake and oxidation of palmitic and oleic acids was higher in arthritic livers. The phenomenon results possibly from a more oxidized state of the arthritic liver. Indeed, NADPH/NADP⁺ and NADH/NAD⁺ ratios were 30% lower in arthritic livers, which additionally presented higher activities of the citric acid cycle driven by both endogenous and exogenous FFA. The lower levels of circulating and hepatic TG possibly are caused by an increased oxidation associated to a reduced synthesis of fatty acids in arthritic livers. These results reveal that the lipid hepatic metabolism in arthritic rats presents a strong catabolic tendency, a condition that should contribute to the marked cachexia described for arthritic rats and possibly for the severe rheumatoid arthritis.

Therapeutic benefits of Indole-3-Carbinol in adjuvant-induced arthritis and its protective effect against methotrexate induced-hepatic toxicity

BACKGROUND

Rheumatoid arthritis (RA) being an incapacitating disease requires early effective intervention. Considering Methotrexate (MTX)- the first line of treatment for RA- intoxicates the liver; therefore, alternative therapies with similar efficacy yet lower cytotoxicity are desired. Indole-3-Carbinol (I3C) which is found in cruciferous vegetables was examined for its possible therapeutic potentials in comparison with MTX by investigating its anti-inflammatory, anti-arthritic, anti-oxidant, and hepatoprotective potentials in adjuvant-induced arthritis (AIA) rat model.

METHODS

Arthritis was induced in Sprague Dawley rats by injection of Complete Freund's Adjuvant (CFA). Arthritic rats were treated with I3C and/or MTX. To examine the anti-inflammatory and anti-arthritic effect, the following parameters were assessed: body weight, macroscopic scoring of the hind paw, the level of the pivotal cytokines (TNF-α, IL-6) heavily involved in the pathogenesis, spleen index, and erythrocyte sedimentation rate. At a histological level, the tibiotarsal joint was stained with several specific stains. To assess the hepatoprotective and anti-oxidant effects, several oxidative stress parameters were monitored, and the liver histology was examined.

RESULTS

Both I3C and MTX attenuated the inflammation that was aggravated by arthritis by downregulating the inflammatory markers and mediators and alleviating the histopathological changes affecting the tibiotarsal joint. I3C attenuated the liver impairment that was initiated by arthritis and MTX treatment. It did so by downregulating the pro-oxidants and up-regulating the anti-oxidant defenses and by reducing the pathological changes affecting the liver.

CONCLUSION

Our results suggest that I3C is as potent as MTX as an anti-inflammatory and anti-arthritic agent. In addition, I3C does so while protecting the liver from damage as opposed to MTX.

Anti-Inflammatory and Antioxidant Actions of Methyl Jasmonate Are Associated with Metabolic Modifications in the Liver of Arthritic Rats

Methyl jasmonate (MeJA) is a fatty acid-derived cyclopentanone which shares structural similarities with prostaglandins and has been under study as a promising anti-inflammatory agent. This study investigated the actions of MeJA on systemic inflammation and oxidative status in rats with adjuvant-induced arthritis, a model for rheumatoid arthritis. MeJA (75 to 300 mg·kg⁻¹) was administrated orally during 18 days after arthritis induction with Freund's adjuvant. Articular and systemic inflammation was greatly increased in arthritic rats, likewise the oxidative stress in plasma and liver. The hepatic glucokinase activity and glycolysis were increased in arthritic rats. MeJA decreased most inflammatory parameters and abolished the increased protein carbonylation in plasma and liver, diminished the increased hepatic ROS content, and restored the hepatic GSH/GSSG ratio in arthritic rats. However, the MeJA treatment decreased the hepatic glucokinase activity and glycolysis and stimulated mitochondrial ROS production in healthy and arthritic rats. Oxygen uptake was increased by MeJA only in livers from treated arthritic rats. This action may bear relation to the increased activity of mitochondrial NADP⁺-dependent enzymes to provide reducing equivalents for the glutathione cycle. These beneficial effects, however, are associated with a decreased glucose flux through the glycolysis in the liver of arthritic and healthy rats.

Food restriction promotes damage reduction in rat models of type 2 diabetes mellitus

There are several animal models of type 2 diabetes mellitus induction but the comparison between models is scarce. Food restriction generates benefits, such as reducing oxidative stress, but there are few studies on its effects on diabetes. The objective of this study is to evaluate the differences in physiological and biochemical parameters between diabetes models and their responses to food restriction. For this, 30 male Wistar rats were distributed in 3 groups (n = 10/group): control (C); diabetes with streptozotocin and cafeteria-style diet (DE); and diabetes with streptozotocin and nicotinamide (DN), all treated for two months (pre-food restriction period). Then, the 3 groups were subdivided into 6, generating the groups CC (control), CCR (control+food restriction), DEC (diabetic+standard diet), DER (diabetic+food restriction), DNC (diabetic+standard diet) and DNR (diabetic+food restriction), treated for an additional two months (food restriction period). The food restriction (FR) used was 50% of the average daily dietary intake of group C. Throughout the treatment, physiological and biochemical parameters were evaluated. At the end of the treatment, serum biochemical parameters, oxidative stress and insulin were evaluated. Both diabetic models produced hyperglycemia, polyphagia, polydipsia, insulin resistance, high fructosamine, hepatic damage and reduced insulin, although only DE presented human diabetes-like alterations, such as dyslipidemia and neuropathy symptoms. Both DEC and DNC diabetic groups presented higher levels of protein carbonyl groups associated to lower antioxidant capacity in the plasma. FR promoted improvement of glycemia in DNR, lipid profile in DER, and insulin resistance and hepatic damage in both diabetes models. FR also reduced the protein carbonyl groups of both DER and DNR diabetic groups, but the antioxidant capacity was improved only in the plasma of DER group. It is concluded that FR is beneficial for diabetes but should be used in conjunction with other therapies.

Water soluble compounds ofRosmarinus officinalisL. improve the oxidative and inflammatory states of rats with adjuvant-induced arthritis

Water soluble compounds of rosemary leaves attenuate oxidative stress and inflammation in arthritic rats.

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.