Blood lymphocyte subsets in rats with adjuvant arthritis

Combinatory Effects of Bone Marrow-Derived Mesenchymal Stem Cells and Indomethacin on Adjuvant-Induced Arthritis in Wistar Rats: Roles of IL-1β, IL-4, Nrf-2, and Oxidative Stress

Rheumatoid arthritis (RA) is a disorder triggered by autoimmune reactions and related with chronic inflammation and severe disability. Bone Marrow-derived Mesenchymal Stem Cells (BM-MSCs) have shown a hopeful immunomodulatory effect towards repairing cartilage and restoring joint function. Additionally, indomethacin (IMC), a nonsteroidal compound, has been considered as a potent therapeutic agent that exhibits significant antipyretic properties and analgesic effects. The target of the current research is to assess the antiarthritic efficacy of BM-MSCs (10⁶ cells/rat at 1, 6, 12 and 18 days) and IMC (2 mg/kg body weight/day for 3 weeks) either alone or concurrently administered against complete Freund's adjuvant-induced arthritic rats. Changes in paw volume, body weight, gross lesions, and antioxidant defense system, as well as oxidative stress, were assessed. The Th1 cytokine (IL-1β) serum level and Th2 cytokine (IL-4) and Nrf-2 ankle joint expression were detected. In comparison to normal rats, it was found that the CFA-induced arthritic rats exhibited significant leukocytosis and increase in paw volume, LPO level, RF, and IL-1β serum levels. In parallel, arthritic rats that received BM-MSCs and/or IMC efficiently exhibited decrease in paw edema, leukocytosis, and enhancement in the antioxidant enzymatic levels of SOD, GPx, GST, and GSH in serum besides upregulation of Nrf-2 and anti-inflammatory IL-4 expression levels in the ankle articular joint. Likewise, these analyses were more evidenced by the histopathological sections and histological score. The data also revealed that the combined administration of BM-MSC and IMC was more potent in suppressing inflammation and enhancing the anti-inflammatory pathway than each agent alone. Thus, it can be concluded that the combined therapy with BM-MSC and IMC may be used as a promising therapeutic choice after assessing their efficacy and safety in human beings with RA, and the antiarthritic effects may be mediated via modulatory effects on Th1/Th2 cytokines, ozidative stress, and Nrf-2.

In vivo anti-arthritic effect and repeated dose toxicity of standardized methanolic extracts of Buddleja cordata Kunth (Scrophulariaceae) wild plant leaves and cell culture

ETHNOPHARMACOLOGICAL RELEVANCE

Buddleja cordata Humb. Bonpl. & Kunth, known by the population as Tepozán blanco, is a shrub plant used in traditional herbal medicine in Mexico for the treatment of tumors, cancer, sores, skin burns, rheumatic pains and diseases related to inflammatory processes such as arthritis; authors adjudicate this etno-medicinal effect to the presence of secondary metabolites in the plant such as verbascoside, however due to its low concentration in recent years biotechnological tools are applied as cell culture to biosynthesize these pharmacological active metabolites in greater quantities.

AIM OF THE STUDY

Evaluate the possible toxic effect after a daily administration of MeOH extracts from wild plant leaves (Bc-Wp), and cell culture (Bc-Cc) of B. cordata for 28 days, and after their anti-edematous and antioxidant activities in vivo, as well their effect on the cytokines profile during experimental arthritis induced by complete Freund's adjuvant.

MATERIALS AND METHODS

Both extracts were evaluated in CD1 male mice first in a toxicity test of repeated dose administrations (1 g/kg) for 28 days, after which pharmacological activity of both extracts was measure during experimental induced arthritis where three doses were tested, at the end of the study edema formation, body weight gain and antioxidant activity were measure in edema and ganglionic tissues. Finally, dose that exerted the best protective effect (250 mg/kg) was evaluated to quantify its effect over ganglionic tissue concentration of lymphocytes T CD4⁺, and cytokines (IL-1β, TNF-α and IL-10), as well histological analysis in arthritic mice.

RESULTS

Both extracts (Bc-Wp and Bc-Cc) did not exert lethality, however body weight gain and food in-take were lower than in healthy mice administered with vehicles, also extract-treated animals showed a decrease in serum lipid concentration and only Bc-Wp extract treated animals decrease serum alkaline phosphatase after 28 daily administration compared to healthy un-treated mice. During experimental arthritis best inhibition effect over edema development was observed in those animals administered with both extracts at dose of 250 mg/kg (Bc-Wp and Bc-Cc) on day 28, compared to CFA un-treated mice. Also both extracts reduce oxidative damage over lipids and proteins at the same dose, in both ganglionic and edema tissue, as well antioxidant enzymatic response was reduced in both tissues compared to arthritic un-treated group. In ganglionic tissue of arthritic mice, CD4⁺ lymphocytes concentration was reduced by Bc-Wp and Bc-Cc treatment (250 mg/kg) respectively, as well IL-1β, and TNF-α levels. Only arthritic animals treated with Bc-Cc extract at 250 mg/kg generated a significant increase of IL-10 doubling the levels compared to CFA un-treated group. Histological analysis of popliteal ganglion showed that both extracts decrease the incidence of lytic lesions, lipid inclusions and leukocyte infiltration.

CONCLUSION

Methanolic extracts of wild Buddleja cordata and its cell cultures did not generated lethality after a daily administration for 28 days at 1 g/kg, but it was observed that both showed a lipid-lowering effect. Also at dose of 250 mg/kg both extracts exerted anti-edematous, protection against the oxidation of lipid and proteins, regulation on antioxidant enzymatic response, down-regulation on lymphocytes CD4⁺ producers of IL-1β and TNF-α, an increase in IL-10 levels, which caused a decrease in leukocyte infiltration in ganglionic tissue during experimental arthritis.

Antioxidant Effect of Spirulina (Arthrospira) maxima on Chronic Inflammation Induced by Freund's Complete Adjuvant in Rats

One of the major mechanisms in the pathogenesis of chronic inflammation is the excessive production of reactive oxygen and reactive nitrogen species, and therefore, oxidative stress. Spirulina (Arthrospira) maxima has marked antioxidant activity in vivo and in vitro, as well as anti-inflammatory activity in certain experimental models, the latter activity being mediated probably by the antioxidant activity of this cyanobacterium. In the present study, chronic inflammation was induced through injection of Freund's complete adjuvant (CFA) in rats treated daily with Spirulina (Arthrospira) maxima for 2 weeks beginning on day 14. Joint diameter, body temperature, and motor capacity were assessed each week. On days 0 and 28, total and differential leukocyte counts and serum oxidative damage were determined, the latter by assessing lipid peroxidation and protein carbonyl content. At the end of the study, oxidative damage to joints was likewise evaluated. Results show that S. maxima favors increased mobility, as well as body temperature regulation, and a number of circulating leukocytes, lymphocytes, and monocytes in specimens with CFA-induced chronic inflammation and also protects against oxidative damage in joint tissue as well as serum. In conclusion, the protection afforded by S. maxima against development of chronic inflammation is due to its antioxidant activity.

Suppression of adjuvant arthritis by hesperidin in rats and its mechanisms

The citrus flavonoid hesperidin has been reported to possess a wide range of pharmacological properties. We have investigated the preventive and therapeutic effects of hesperidin on the development of adjuvant arthritis (AA), a rat model of rheumatoid arthritis (RA). Freund's complete adjuvant was used to induce AA in rats. Secondary paw swelling, polyarthritis index and histopathological assessment of ankle joints were used to evaluate the effects of hesperidin on AA rats. Concanavalin-A-induced T-lymphocyte proliferation and interleukin (IL)-2 production by splenocytes were measured using the MTT assay. Levels of IL-1, IL-6 and tumour necrosis factor (TNF)-α secreted by peritoneal macrophages (PM) were measured by RIA. Intragastric administration of hesperidin significantly attenuated secondary paw swelling and reduced the polyarthritis index of AA rats in a dose-dependent manner. In addition, hesperidin clearly ameliorated the pathological changes in AA rats. Hesperidin also restored the suppression of T-lymphocyte proliferation and IL-2 production, and downregulated production of IL-1, IL-6 and TNF-α by PM in AA rats. Our results suggest that hesperidin improves AA by downregulating the function of over-active macrophages and by up-regulating the activities of dysfunctional T lymphocytes. Hesperidin may therefore have therapeutic value for the clinical treatment of RA. Further research is required to clarify the detailed mechanisms of the protective effects of hesperidin on AA.

Effect of 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles on chronic inflammatory pain model in rats

Nonsteroidal antiinflammatory drugs (NSAIDs) are commonly used for treatment of arthritis. However, their long-term use has been associated with considerable morbidity, limiting their application. Thus, there remains a need to develop new drugs for the effective and safe relief of chronic inflammatory pain. In this context, the present study was designed to evaluate the antinociceptive and antiedematogenic effects of the 5-trifluoromethyl-4,5-dihydro-1H-pyrazole derivatives EPFCA3 and MPFCA4 after acute (1-1000 micromol/kg) and chronic (100 micromol/kg for 15 days) administration in rats submitted to a model of adjuvant-induced arthritis. We also analyzed some biochemical indicators of toxicity (alanine aminotransferase, aspartate aminotransferase, urea and creatinine levels) after prolonged administration of these compounds. We found that acute and chronic subcutaneuous administration of EPFCA3 and MPFCA4 produces an antinociceptive, but not antiedematogenic, effect on the arthritis animal model induced by complete Freund's adjuvant (CFA). No signs of toxicity were observed in the animals chronically treated with EPFCA3 or MPFCA4. Dipyrone (1-1000 micromol/kg) was used as the positive control and its effect was similar to that of the novel pyrazoles. The activity of tissue myeloperoxidase, the tissue TNF-alpha level and the serum haptoglobin level was increased by intraplantar CFA injection. However, chronic administration of EPFCA3, MPFCA4 or dipyrone was not able to alter the relation between these parameters and inflammation. Our results suggest that EPFCA3 and MPFCA4 are good candidates for the development of new drugs for pain treatment.

Possible stimulation of anti-tumor immunity using repeated cold stress: a hypothesis

Background

The phenomenon of hormesis, whereby small amounts of seemingly harmful or stressful agents can be beneficial for the health and lifespan of laboratory animals has been reported in literature. In particular, there is accumulating evidence that daily brief cold stress can increase both numbers and activity of peripheral cytotoxic T lymphocytes and natural killer cells, the major effectors of adaptive and innate tumor immunity, respectively. This type of regimen (for 8 days) has been shown to improve survival of mice infected with intracellular parasite Toxoplasma gondii, which would also be consistent with enhanced cell-mediated immunity.

Presentation of the hypothesis

This paper hypothesizes that brief cold-water stress repeated daily over many months could enhance anti-tumor immunity and improve survival rate of a non-lymphoid cancer. The possible mechanism of the non-specific stimulation of cellular immunity by repeated cold stress appears to involve transient activation of the sympathetic nervous system, hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axes, as described in more detail in the text. Daily moderate cold hydrotherapy is known to reduce pain and does not appear to have noticeable adverse effects on normal test subjects, although some studies have shown that it can cause transient arrhythmias in patients with heart problems and can also inhibit humoral immunity. Sudden immersion in ice-cold water can cause transient pulmonary edema and increase permeability of the blood-brain barrier, thereby increasing mortality of neurovirulent infections.

Testing the hypothesis

The proposed procedure is an adapted cold swim (5–7 minutes at 20 degrees Celsius, includes gradual adaptation) to be tested on a mouse tumor model. Mortality, tumor size, and measurements of cellular immunity (numbers and activity of peripheral CD8+ T lymphocytes and natural killer cells) of the cold-exposed group would be compared to those of control groups (warm swim and no treatment). Cold-water stress would be administered twice a day for the duration of several months.

Implications of the hypothesis

If the hypothesis is supported by empirical studies and the method is shown to be safe, this could lead to the development of an adjunctive immunotherapy for some (non-lymphoid) cancers, including those caused by viral infections.

Effect of FTY720, a novel immunosuppressant, on adjuvant- and collagen-induced arthritis in rats

The anti-arthritic effect of FTY720, 2-amino-2-[2-(4-octylphenyl)ethyl]propane-1,3-diol hydrochloride, a novel immunosuppressant which induces peripheral lymphocyte homing to peripheral lymph nodes, was compared with those of anti-rheumatic compounds, mizoribine and prednisolone in rat adjuvant-induced arthritis (AA) and collagen-induced arthritis (CIA). FTY720 at doses of 0.03-0.3 mg/kg, mizoribine at 3-30 mg/kg, and prednisolone at 1-10 mg/kg were orally administered to rats for 21 days from the day of inoculation with heat-killed Mycobacterium tuberculosis or type II collagen. Efficacy of FTY720 at 0.3 mg/kg was almost equal or higher as compared with those of mizoribine and prednisolone in both AA and CIA models. FTY720, but not mizoribine and prednisolone, decreased selectively lymphocyte counts in the peripheral blood in both models below the levels of the normal rats. Although FTY720 gave no other abnormal signs resulting in side effects, mizoribine was lethal to rats at 30 mg/kg and prednisolone inhibited body weight gain at 10 mg/kg, indicating that FTY720 has a wider margin of safety compared with these reference compounds. FTY720 also inhibited the production of anti-collagen antibody in CIA model, while neither mizoribine nor prednisolone did it. These results suggest that FTY720 is a promising compound for the treatment of arthritis with a unique profile.

Immunohistochemical study of lymphoid tissues in adjuvant arthritis (AA) by image analysis; relationship with synovial lesions

The aim of this study was to examine leucocyte populations in lymphoid organs during AA and to ascertain the relationship with lesions in synovial joints. Popliteal lymph nodes, spleen and knee synovial membranes were removed from both healthy and AA rats at intervals of 3-4 days over a 3-week period. Cryostat sections were stained with MoAbs directed against lymphocyte and macrophage subpopulations, and studied by image analysis. Throughout the arthritic period, high numbers of ED1+ and ED3+ macrophages were seen in both lymphoid compartments and intercellular adhesion molecule-1 (ICAM-1) expression also increased in some zones of lymph nodes and spleen. The percentages of CD4+ and CD8+ cells rose in the splenic zones studied but fell in the lymph node cortex. Very few natural killer (NK) cells were found in lymphoid tissues, but the number rose after AA induction. In synovia from AA rats, ED2+ macrophages proliferated but alpha/beta T cell infiltration was only occasionally observed, accompanied by ED1+ cells and ICAM-1 expression. In conclusion, synovitis developing after AA induction seems to be caused directly by macrophages and indirectly by lymphocytes placed both in popliteal lymph nodes and spleen.

Alterations of lymphocyte populations in lymph nodes but not in spleen during the latency period of adjuvant arthritis

The aim of this study was to analyze potential imbalances in lymphocyte populations from regional lymph nodes (LN) and spleen occurring before the development of the outer inflammation of adjuvant arthritis (AA). Percentages and absolute numbers of CD5+, CD4+, CD8+, Ig+, I-A+, NKR-P1+ and TCRgammadelta+ cells were determined. No differences in percentages of gammadelta T or NK cells were found either in LN or spleen, thus ruling out an important role of these minor subpopulations in these early stages of AA. While no significant lymphocyte imbalances were observed in spleen, an increase in the percentage of B lymphocytes was found in regional LN. Moreover, a high proliferation of CD8+ cells was observed when measuring absolute numbers of LN lymphocytes, thus producing an imbalance in the CD4/CD8 ratio at very early stages of the inflammatory process. These findings suggest a role for CD8+ and B lymphocytes in the latency period of AA at the LN level. Our results indicate a primary role for lymph nodes in initiating the inflammation of AA, whereas cells from the spleen probably play a secondary role.

Protection of rats from adjuvant arthritis by immunization with naked DNA encoding for mycobacterial heat shock protein 65

OBJECTIVE

To assess the feasibility of vaccination with naked DNA encoding for mycobacterial heat shock protein 65 (hsp65) in the modulation of experimental arthritis.

METHODS

Adjuvant arthritis (AA) was induced in Lewis rats preimmunized, intramuscularly, with a plasmid encoding for hsp65 (pCMV3.65). Clinical scores were recorded for 3-4 weeks, and histologic and radiologic parameters were evaluated. Cellular and antibody reactivity to hsp65 was assessed. The expression of the hsp65 gene was investigated in injected muscles.

RESULTS

The pCMV3.65-treated rats were significantly protected from disease development in comparison with the control groups. This finding correlated with the results of histologic and radiologic examinations of the involved joints. The message for hsp65 was detected in injected muscles. T cell proliferation and antibodies to this protein were found to be elevated in pCMV3.65-treated rats when compared with both the arthritic control (AA-induced) and the naive (did not receive adjuvant) animals.

CONCLUSION

We have demonstrated for the first time that naked DNA delivery is feasible in controlling experimental autoimmune disease. Although the actual mechanism of protection has not been fully elucidated, this simple and versatile approach could represent a useful tool in dissecting basic autoimmune mechanisms.