Interaction between inhibitors of inducible nitric oxide synthase and cyclooxygenase in adjuvant-induced arthritis in female albino rats: an isobolographic study

Cobalt-Catalyzed Vinylic C-H Addition to Formaldehyde: Synthesis of Butenolides from Acrylic Acids and HCHO

A carboxyl-assisted C-H functionalization of acrylic acids with formaldehyde to give butenolides is described. It is the first time that the addition of an inert vinylic C-H bond to formaldehyde has been achieved via cobalt-catalyzed C-H activation. The unique reactivity of the cobalt species was observed when compared with related Rh or Ir catalysts. γ-Hydroxymethylated butenolides were produced by the treatment of Na₂CO₃ after the catalytic reaction in one pot.

Attenuation of oxidative stress in arthritic rats by ethanolic extract of Albizia procera benth bark through modulation of the expression of inflammatory cytokines

ETHNOPHARMACOLOGICAL RELEVANCE

Albizia procera L. (Leguminosae) commonly known as Konda vagai in Tamil, is used for the treatment of stomach and intestinal disorders. A decoction of the bark is prescribed for rheumatism and haemorrhage. Traditionally, literature claims Albizia procera as a drug to have antirheumatic properties and hence used by Tribal for the management of chronic rheumatism. Consequently, the present study has been undertaken to illustrate the beneficial outcome of Albizia procera in adjuvant induced arthritic rat model with respect to its antioxidant and anti-inflammatory activities.

AIM OF THE STUDY

The present study is aimed to investigate the oxidative stress and the expression of inflammatory markers in arthritic rats treated with ethanolic bark extract of Albizia procera.

MATERIALS AND METHODS

Ethanolic bark extract was characterized by HPTLC analysis. Acute oral toxicity study was performed according to the OECD test guideline 423 - Acute toxic class method. The anti-inflammatory effect of ETBE (100, 200 mg/kg/day/p.o.) was evaluated in complete Freund's adjuvant induced arthritic rats using diclofenac as positive control (0.3 mg/kg/day/p. o.). Plasma levels of interleukins TNF- α, IFN-α, IL-2, IL-6, myeloperoxidase and Cathepsin D levels were measured to assess the inflammatory effect of ETBE extract of Albizia procera. Further, the effect of ETBE on superoxide dismutase (SOD), glutathione peroxidase (GPX), reduced glutathione (GSH) and lipid peroxidation (LPO) were assessed in plasma.

RESULTS

HPTLC analysis showed the presence of 0.57% w/w of biochanin-A in ETBE. ETBE did not show any toxic signs up to 2000 mg/kg body weight. It exhibited the significant anti-inflammatory and antioxidant potential and did not show mortality up to 2000 mg/kg body weight. ETBE treatment significantly reduced the levels of TNF- α, IFN-α, IL-2, IL-6 and myeloperoxidase, and increased cathepsin D levels compared to vehicle treated animals. SOD, GSH and GPX levels were significantly restored to normal levels while LPO was significantly reduced at 200 mg/kg b. wt. Treated animals. Histopathological studies showed complete cartilage regeneration and near normal joint in ETBE treated arthritic rats.

CONCLUSION

ETBE demonstrated potent anti-inflammatory activity by modulating the expression of inflammatory cytokines and restoring the antioxidant enzyme levels.

Mefenamic acid decreases inflammation but not joint lesions in experimental osteoarthritis

Mefenamic acid is a non-steroidal anti-inflammatory drug able to control the symptoms of osteoarthritis (OA), but its effects on protection of cartilage and bone are still unclear. This study aimed to investigate whether the control of inflammation by mefenamic acid translates into decreased joint lesions in experimental OA in rats. OA was induced by injecting 1 mg of monosodium iodoacetate (MIA) into the joints of rats. The animals were treated with mefenamic acid (50 mg/kg, daily, oral gavage) either pre-MIA injection (preventive) or post-MIA injection (therapeutic). Joint swelling and hyperalgesia were evaluated at baseline and 1, 3, 14 and 28 days after induction of OA. Intra-articular lavage and kinetics of cell migration into the synovium were measured 3 and 28 days after OA induction. Histopathological analysis, Osteoarthritis Research Society International (OARSI) score, total synovium cells count, cartilage area and levels of proteoglycans in joints were also evaluated. Mefenamic acid prevented joint oedema and hyperalgesia induced by MIA in the acute phase (3 days) of the disease. In the chronic phase (28 days), preventive and therapeutic regimens decreased the number of mononuclear cells in the joint cavity. In contrast, thickening of the synovium, bone resorption, loss of cartilage and levels of proteoglycans were unaffected by mefenamic acid when it was administered either preventively or therapeutically. Thus, mefenamic acid had anti-inflammatory effects but did not reduce the progression of OA lesions, thereby indicating that it is only effective for symptomatic control of OA.

Effect of new polyherbal formulations DF1911, DF2112 and DF2813 on CFA induced inflammation in rat model

BACKGROUND

Aim of the present study was to evaluate anti-inflammatory activity of newly developed polyherbal formulations DF1911, DF2112 and DF2813. These newly developed formulations are modifications of Dashamoola, a well known Ayurvedic formulation, along with addition of new plants.

METHODS

Complete Freund's adjuvant (CFA) induced inflammation in rat was used as an experimental model. Effects of the treatment in rats were monitored by physiological and biochemical parameters, histopathology and through gene expression studies.

RESULTS

Diclofenac sodium showed maximum percentage inhibition (56.8 ± 3.5%) of paw edema followed by Dashamoola Kwatha (19.9 ± 1.8%). Among test formulations treated groups, DF1911 at 250 mg/kg bw (48.2 ± 5.4%, p < 0.001) and DF2112 at 250 mg/kg bw (49.9 ± 3.5%, p < 0.001) showed significant and maximum increase in percentage inhibition of paw edema as compared to Dashamoola Kwatha. Hematological alterations in CFA rats were normalized after treatment with test formulations. Results of serum markers and histopathological observations also supported the activity of formulations. Increased MDA levels in liver tissue of CFA injected animals significantly (p < 0.05) decreased by Diclofenac sodium and test formulation treated groups. DF1911, DF2112 and DF2813 showed down-regulation of IL1-β (~6.4-fold, ~5.2-fold and ~7.6-fold), IL-6 (~1.1-fold, ~1.6-fold and ~1.9-fold), TNF-α (~2.0-fold, ~4.6-fold and ~3.5-fold), and iNOS (~1.2-fold, ~1.8-fold and ~1.1-fold) in inflamed paw tissue compared to negative control group, respectively.

CONCLUSIONS

The anti-inflammatory effects of DF1911 and DF2112 in rats were significantly higher than the Dashamoola Kwatha and are comparable to Diclofenac sodium.

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.

Simvastatin reduces leucocyte- and platelet-endothelial cell interaction in murine antigen-induced arthritis in vivo

OBJECTIVES

The use of statins in the prevention and treatment of cardiovascular diseases is well established. Their use as anti-inflammatory and immunomodulatory agents in the treatment of rheumatoid arthritis (RA) has also been investigated, with several clinical and experimental studies indicating an anti-inflammatory effect of statins for RA, but other studies showing no effect or even the opposite. The current study was designed to examine the effect of simvastatin in an in vivo murine model of arthritis using intravital microscopy.

METHOD

We assigned four groups (n = 7, female C57Bl6 mice), two with and two without antigen-induced arthritis (AiA), from which one of the non-AiA groups and one of the AiA groups were treated with simvastatin 40 mg/kg i.p. daily for 14 consecutive days after induction of arthritis. Platelet- and leucocyte-endothelial cell interaction was assessed by measurement of rolling and adherent fluorescence-labelled platelets and leucocytes, functional capillary density (FCD) was evaluated, and knee joint diameter was determined as a clinical parameter.

RESULTS

In arthritic mice treated with simvastatin, a significant reduction in platelet- and leucocyte-endothelial cell interaction was observed in comparison to arthritic mice treated with vehicle. In addition, a significant reduction in FCD was seen in arthritic mice treated with simvastatin, along with a reduction in knee joint swelling of the AiA mice.

CONCLUSIONS

Treatment of AiA mice with simvastatin showed significant reductions in platelet- and leucocyte-endothelial cell interactions, in FCD, and in the swelling of the knee joint. These results support the hypothesis of the anti-inflammatory effects of statins in the treatment of RA.

Evaluation of anti-inflammatory potential of the multidrug herbomineral formulation in male Wistar rats against rheumatoid arthritis

Background:

Immunological and inflammatory mechanisms, which may play a role in a number of disorders like rheumatoid arthritis (RA). Ancient ayurvedic physicians had developed certain dietary and therapeutic measures to arrest or prevent these disorders.

Objective:

Rheuma off gold (RG) is a herbomineral formulation recommended by ayurvedic medical practitioners for treatment of RA. This study was carried out to lend scientific evidence to the efficacy claim for RG in the management of RA in folklore medicine.

Materials and Methods:

Arthritis was induced by complete Freund's adjuvant. Treatment with formulation 100 mg/kg and dexamethasone 2 mg/kg was given to rats intragastrically once a day from day 1 to day 21 and after which estimation of physical, biochemical, and hematological parameters were carried out.

Results:

Treatment of formulation to adjuvant induced arthritic animal showed statistically significant (P < 0.05) improvement in physical parameters like arthritic index, paw edema, paw thickness as well as reduction of inflammatory markers like C-reactive protein, serum rheumatoid factor, erythrocyte sedimentation rate. The treatment also produced statistically significant (P < 0.05) increase in hemoglobin percent and improvement in splenomegaly and thymus index. In the histopathological examination, ameliorative effect of formulation was observed in hyperplasia of synovium, pannus formation, and destruction of the joint space.

Conclusion:

The results obtained in experiments indicated that the formulation significantly inhibited the adjuvant-induced arthritis which was comparable to dexamethasone and had preferable anti-inflammatory effect without significant side effect. Thus, the formulation may be a potential preventive or therapeutic candidate for the treatment of chronic inflammation and arthritis.

Synergistic depression of NMDA receptor-mediated transmission by ketamine, ketoprofen and L-NAME combinations in neonatal rat spinal cords in vitro

BACKGROUND AND PURPOSE

Spinal N-methyl-D-aspartate (NMDA) receptor/cyclooxygenase (COX) and nitric oxide synthase (NOS) pathways play a major role in nociceptive processing, and influencing them simultaneously may induce synergistic analgesia. This study determined the spinal antinociceptive interactions between ketamine (NMDA receptor channel blocker), ketoprofen (COX inhibitor) and L-NAME (NOS inhibitor) combinations.

EXPERIMENTAL APPROACH

Using an in vitro neonatal rat spinal cord preparation, two A-fibre-mediated reflexes, the monosynaptic reflex (MSR) and the low-intensity excitatory postsynaptic potential (epsp), and one C-fibre-mediated reflex, the high-intensity epsp, were evoked electrically. The effect of drugs and drug combinations on these reflexes was assessed and the type of interaction determined by isobolographic analysis.

KEY RESULTS

Infusion of ketamine alone decreased all three reflexes. That of ketoprofen decreased both the low and the high-intensity epsp only. Infusion of L-NAME alone produced no significant effects. Co-infusion of fixed ratios of IC(40) fractions of both (ketamine+ketoprofen) and (ketamine+L-NAME) were synergistic for depressing the low and the high-intensity epsps. The interaction was sub-additive for both combinations on the MSR. The only significant effect for the (ketoprofen+L-NAME) combination was synergism on the high-intensity epsp.

CONCLUSIONS AND IMPLICATIONS

All three combinations synergistically depressed nociceptive spinal transmission, and both ketamine and ketoprofen and ketamine and L-NAME combinations did so with potentially decreased motor side effects. If such combination profiles also occur in vivo, the present findings raise the possibility of ultimate therapeutic exploitation of increased analgesia with fewer side effects.