Lithothamnion muelleri treatment ameliorates inflammatory and hypernociceptive responses in antigen-induced arthritis in mice.

Rheumatoid Arthritis (RA) is a chronic disease characterized by persistent inflammation and pain. Alternative therapies to reduce these symptoms are needed. Marine algae are valuable sources of diverse bioactive compounds. Lithothamnion muelleri (Hapalidiaceae) is a marine algae with anti-inflammatory, antitumor, and immunomodulatory properties. Here, we investigated the potential anti-inflammatory and analgesic activities of L. muelleri in a murine model of antigen-induced arthritis (AIA) in mice. Our results demonstrate that treatment with L. muelleri prevented inflammation and hypernociception in arthritic mice. Mechanistically, the crude extract and the polysaccharide-rich fractions of L. muelleri may act impairing the production of the chemokines CXCL1 and CXCL2, and consequently inhibit neutrophil influx to the knee joint by dampening the adhesion step of leukocyte recruitment in the knee microvessels. Altogether our results suggest that treatment with L.muelleri has a potential therapeutic application in arthritis treatment.

Selective targeted delivery of the TNF-alpha receptor p75 and uteroglobin to the vasculature of inflamed tissues: a preliminary report.

BACKGROUND: Ligand-targeted approaches have proven successful in improving the therapeutic index of a number of drugs. We hypothesized that the specific targeting of TNF-alpha antagonists to inflamed tissues could increase drug efficacy and reduce side effects. RESULTS: Using uteroglobin (UG), a potent anti-inflammatory protein, as a scaffold, we prepared a bispecific tetravalent molecule consisting of the extracellular ligand-binding portion of the human TNF-alpha receptor P75 (TNFRII) and the scFv L19. L19 binds to the ED-B containing fibronectin isoform (B-FN), which is expressed only during angiogenesis processes and during tissue remodeling. B-FN has also been demonstrated in the pannus in rheumatoid arthritis. L19-UG-TNFRII is a stable, soluble homodimeric protein that maintains the activities of both moieties: the immuno-reactivity of L19 and the capability of TNFRII to inhibit TNF-alpha. In vivo bio-distribution studies demonstrated that the molecule selectively accumulated on B-FN containing tissues, showing a very fast clearance from the blood but a very long residence time on B-FN containing tissues. Despite the very fast clearance from the blood, this fusion protein was able to significantly improve the severe symptomatology of arthritis in collagen antibody-induced arthritis (CAIA) mouse model. CONCLUSIONS: The recombinant protein described here, able to selectively deliver the TNF-alpha antagonist TNFRII to inflamed tissues, could yield important contributions for the therapy of degenerative inflammatory diseases.

Joint preventive effects of swimming and Shenlian extract on rat atherosclerosis.

This work is to investigate the joint effect of extract from Shenlian (SL, the Chinese abbreviation for Radix Salviae miltiorrhizae and Andrographis paniculata) and swimming on atherosclerosis prevention and treatment. Atherosclerotic rat model was established by combining low shear stress by partial ligation of common carotid artery with afterwards feeding of a hyperlipotic diet. Sprague-Dawley rats after partial ligation of common carotid artery were allotted to a 3 × 3 factorial design with three levels of swimming (0, 1, and 2 hr per day) and three levels of SL extract (0, 2.56, and 5.12 g/kg once daily p.o.) for a total of 9 treatment groups. Then, the feeding of the hyperlipotic diet and the intervention of swimming and SL started at the same time, and lasted for 8 weeks. By the end, blood samples were collected to determine blood viscosity, hematocrit, blood lipids, MCP-1, NF-κB and NO levels. The common carotid arteries of the rats were harvested to investigate pathological changes. The animal model showed early sign of atherosclerosis according to the pathological findings. Joint effects of SL extract and swimming on preventing atherosclerosis appeared significantly: The combination of 1 hour swimming with 2.56 g/kg SL extract showed to be effective for lowering hematocrit, blood viscosity (at 10 s(-1) and 200 s(-1)) and low-density-lipoprotein (p < 0.001). Combined treatment of 2.56 g/kg SL extract with 2 hr swimming led to a synergistic decrease in serum level of MCP-1. As a single factor, SL extract (2.56 g/kg) alone could decrease serum levels of NF-κB significantly (p = 0.003). Swimming alone could decrease cholesterol, triacylglycerols level and increase high-density-lipoprotein. The study demonstrates the combined therapy of oral SL extract with swimming on inhibiting inflammatory factors, improving hemorheological parameters and lipoproteins in rat model of atherosclerosis. It highlights the promising effects of the drugs and shear stress of blood flow, the biomechenopharmacological means, for prevention of atherosclerosis.

Scopolin isolated from Erycibe obtusifolia Benth stems suppresses adjuvant-induced rat arthritis by inhibiting inflammation and angiogenesis.

Despite scopolin is a main coumarin constituent in the stems of Erycibe obtusifolia Benth, a herb drug that has long been utilized in traditional Chinese medicine for the treatment of rheumatoid arthritis, little information is available about the pharmacological activities of this compound. The present study was performed to investigate the anti-rheumatic effects of scopolin in adjuvant-induced arthritis (AIA) in rats, and explore the underlying mechanisms of action in views of anti-inflammatory and anti-angiogenic properties in the synovial tissues. Scopolin (50, 100 mg/kg), injected intraperitoneally for 10 days from the onset of secondary response, significantly inhibited both inoculated and non-inoculated paw swelling as well as articular index scores in AIA. Meanwhile, the mean body weight of rats treated with scopolin was higher than that of model group. Rats treated with high dose of scopolin (100 mg/kg) preserved a nearly normal histological architecture of the joints and showed a significant reduction of the new blood vessels in the synovial tissues. Additionally, scopolin could reduce IL-6, VEGF and FGF-2 expressions in rat synovial tissues. In conclusion, scopolin can reduce the clinical symptoms of rat AIA by inhibiting inflammation and angiogenesis, and this compound may be a potent agent for angiogenesis related diseases and can serve as a structural base for screening more potent synthetic analogs.

Mechanisms of the vasorelaxant effect of Danshen (Salvia miltiorrhiza) in rat knee joints.

The aim of this study is to investigate the mechanisms of the vasorelaxant effect of the crude extract of Salvia miltiorrhiza (family: Labiatae), also known as "Danshen", in rat knee joints. Changes in blood flow of rat knee joints were measured in vivo by a laser Doppler perfusion imager. Topical administration of Danshen onto the exposed knee joint blood vessels produced dose-dependent increases in blood flow. Treatment of the rat knee joint with 2x 1 nmol of atropine, 2x 0.1 nmol of propranolol, or 2x 0.1 nmol of a mixture of pyrilamine plus cimitedine produced no change on the vasodilator response to Danshen. However, significant inhibition of the Danshen-induced vasodilator response was observed in knee joints treated with 2x 100 nmol of N(G)-nitro-L-arginine methyl ester (L-NAME), 2x 100 nmol of flurbiprofen, 2x 10 nmol of the calcitnonin gene-related peptide (CGRP) receptor antagonist CGRP(8-37), and also in knee joints but had been denervated by capsaicin treatment or by surgery. Intravenous administration of low doses of Danshen (2.5 and 6 mg/kg) did not affect the systemic blood pressure but significantly increased knee joint blood flow, whereas, high doses of Danshen (167 and 381 mg/kg) produced hypotension with concurrent decreases in knee joint blood flow. These findings indicate that the knee joint blood vessels are more sensitive to the relaxant effect of Danshen compared to blood vessels in the general circulation. The vasorelaxant effect of Danshen was found to be partly mediated by CGRP released from sensory nerves, and nitric oxide and prostaglandins also played a part. However, there is no evidence to support a role for muscarinic receptors, adrenoceptors, or histamine receptors.

Diagnostic usefulness of synovial vascular morphology in chronic arthritis. A systematic survey of 100 cases.

OBJECTIVES: To assess the diagnostic usefulness of the systematic analysis of synovial vascular morphology in various inflammatory, early, and longstanding arthropathies, and to examine the validity of the vascular patterns in predicting the evolution of a group of patients with undifferentiated arthritis (UA). METHODS: One hundred patients who underwent rheumatologic arthroscopy of a symptomatic joint (85 knees, 11 wrists, 3 elbows, 1 metacarpophalangeal joint) were evaluated. The same observer, blinded to patient diagnosis, analyzed the video recordings of the arthroscopies. Vascular morphology was classified into 3 patterns: straight, tortuous, and mixed. RESULTS: Eighty-one patients had inflammatory arthritis: 35 rheumatoid arthritis (RA), 16 psoriatic arthritis (PsA), 13 spondyloarthropathies (SpA), and 17 UA. Forty-nine percent of patients with RA had a straight pattern, 28% a mixed, and 23% a tortuous one. The sensitivity rate of the straight pattern for RA was 77% and the specificity rate was 70%. Seventy-six percent of RA patients with a straight pattern were rheumatoid factor positive (RF+) against 25% of RA patients with a tortuous pattern. The odds ratio for RA associated to straight compared with tortuous pattern was 57.3 (95% confidence interval, 6.6 to 499.5; P <.001). Patients with PsA and SpA shared the same pattern and were analyzed as 1 group. Ninety-three percent of patients with PsA/SpA had a tortuous pattern, 4% a straight pattern, and 3% a mixed pattern. The sensitivity rate of the tortuous pattern for PsA/SpA was 61% and the specificity rate was 95%. During 2 years of follow-up, 6 of 17 patients with UA were definitely diagnosed: 4 RA (2 RF+ and straight pattern; 2 with a tortuous pattern, 1 with RF+ and HLA-B27+); 1 SpA and 1 PsA, both with a tortuous pattern. No differences in vascular patterns were observed according to disease duration. Our results indicate that vascular patterns are not modified by disease modifying antirheumatic drug (DMARD) treatment. The other 19 patients had osteoarthritis (n = 8) and calcium pyrophosphate dihydrate crystal deposition disease (n = 11) and their predominant vascular pattern was tortuous-like. CONCLUSIONS: Arthroscopic assessment of synovial vascular changes in chronic arthritis may be of diagnostic and pathogenetic interest, although differences between published studies suggest a need for consensus in evaluating vascular patterns. A straight pattern is strongly associated with RF + RA whereas a tortuous pattern is generally associated with PsA or SpA; these associations are independent of disease duration. The vascular pattern likely does not change qualitatively with DMARD therapy. The application of this technique to the diagnosis or prognosis of patients with UA may be a complementary tool for the treatment of these patients, but larger, prospective studies are necessary to confirm this hypothesis.

Decreased response of rat knee joint blood vessels to phenylephrine in chronic inflammation: involvement of nitric oxide.

The effect of chronic inflammation induced by Freund's Complete Adjuvant (FCA) on rat articular blood vessels and knee joint diameter was investigated. Blood flow changes in response to phenylephrine (an 1-adrenoceptor agonist) in FCA-treated and contralateral knee joints were studied over a 40 day period, using the laser Doppler flowmetery (LDF) technique. Unilateral injection of FCA (0.2 ml) increased the injected knee diameter on all days examined post-injection (P < 0.001) and its maximum increase (53 +/- 2 %) was reached on day 3. After this, the diameter decreased gradually but did not return to its initial value. In control animals, topical application of 10-13-10- 7 mol phenylephrine onto the exposed joint capsule decreased blood flow dose dependently (11. 1 +/- 4.4 to 58.2 +/- 4.5 %, respectively, P < 0.001). Unilateral injection with FCA attenuated the phenylephrine response in both ipsilateral and contralateral knees compared with the response of control animals (5.2 +/- 1.6 to 48.3 +/- 6.1 % and 1.9 +/- 2.2 to 45. 3 +/- 5.6 %, respectively, P < 0.05). The reduction persisted for 3 weeks after FCA injection (ipsilateral for 21 days; contralateral for 30 days, P < 0.001). Subsequently the response returned towards normal. To avoid the influence of 2-adrenoceptors, yohimbine (an 2-adrenoceptor antagonist) was injected (0.5 mg kg-1, I.P.) 30 min before phenylephrine application. Yohimbine blocked the vasoconstrictor effect of 10-10-10-7 mol clonidine (an 2-adrenoceptor agonist, topical application) by 44-67.7 % inhibition, respectively (P < 0.001). Prazosin (an 1-adrenoceptor antagonist, 0.1 mg kg-1, I.P.) blocked the vasoconstrictor effect of phenylephrine (10-10-10-7 mol, topical application) effectively (42 to 69.8 % inhibition, respectively, P < 0.001). To assess the role of nitric oxide (NO) on the observed responses, N G-nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) was applied topically (0.2 micromol) 5 min before phenylephrine application. L-NAME application at 7 and 14 days after FCA injection potentiated the vasoconstrictor response in the FCA-treated knee (P < 0.001) but had no significant effect on the contralateral knee. Blood pressure monitoring during phenylephrine, clonidine and L-NAME administration indicated that topical application of the drugs had no significant effect on the systemic blood pressure. These findings indicate that the vasoconstrictor response to phenylephrine was decreased in chronic inflammation and increased NO production could be involved.

Local hemodynamics, permeability, and oxygen metabolism during acute inflammation of innervated or denervated isolated equine joints.

OBJECTIVES: To determine oxygen metabolism, permeability, and blood flow in isolated joints in response to interleukin 1beta (IL-1beta) and contribution of innervation. SAMPLE POPULATION: One metacarpophalangeal (MCP) joint of 24 adult horses. PROCEDURE: The MCP joint was isolated for 6 hours in a pump-perfused, auto-oxygenated, innervated or denervated preparation. Isolated joints were assigned to the following 4 groups: control, control-denervated, inflamed, and inflamed-denervated, and inflammation was induced by intra-articular injection of IL-1beta. Circuit arterial and venous pressures, flows, and blood gas tensions, synovial fluid production, and intra-articular pressure were measured. Total vascular resistance; oxygen delivery, consumption, and extraction ratio (ER); and permeability surface area product were calculated. Synovial membrane blood flow was determined at 0, 60, and 330 minutes. Synovial membrane wet-to-dry ratio was obtained, and permeability to macromolecules was determined by intra-articular injection of Evans blue albumin and fluorescein isothiocyanate-conjugated dextran. RESULTS: Oxygen delivery and synovial membrane blood flow progressively increased but were not different among groups. Oxygen consumption and ER significantly increased in inflamed joints, as did intraarticular pressure and synovial fluid production. Inflamed joints had greater wet-to-dry ratio. Albumin permeability significantly increased in the villous synovial membrane of the inflamed groups, and dextran permeability was increased in the innervated groups, with a trend toward increased permeability in inflamed groups. CONCLUSION: Inflammation significantly increased oxygen demand, which was initially met by increased ER. Permeability to small molecules was increased with inflammation; innervation increased permeability to large molecules. Use of an isolated joint model enabled documentation of the physiologic responses of the joint to acute inflammation.

Physiological characterization of mBSA antigen induced arthritis in the rat. II. Joint blood flow, glucose metabolism, and cell proliferation.

OBJECTIVE: Based on the hypothesis that blood flow in the inflamed joint is inadequate to maintain aerobic glycolysis, we sought to estimate the correlation between blood flow, glucose metabolism, and cellular proliferation rate in the arthritic joint. METHODS: Experiments were performed on rats with antigen induced arthritis (AIA). Regional blood flows (RBF) were measured with the microsphere technique, glucose metabolism by determination of [14C]2-deoxy-D-glucose (2-DG) uptake, and the proliferative response as the incorporation of [3H]-thymidine. RESULTS: In periarticular soft tissue of the arthritic knee the only significant change in the weight related RBF was an approximate 70% rise on Day 14 after arthritis onset. The RBF was lowest on Day 3 and the time course for the changes was inversely related to intensity of vascular inflammation. Weight related 2-DG uptake was more elevated than the RBF and peaked on Day 3. [3H]-thymidine incorporation in the soft tissue was only markedly enhanced on Day 3. Neither 2-DG nor [3H]-thymidine uptake was affected by treatment with methotrexate or indomethacin. In epiphyseal bone RBF was reduced on the first day of arthritis, but steadily increased thereafter. CONCLUSION: In AIA an intense vascular leakiness negatively affects the synovial blood. There is a marked enhancement of glucose metabolism, but only a minor part of this increase seems to be induced by increased cellular proliferation.