Reduction of oxidative stress in adjuvant arthritis. Comparison of efficacy of two pyridoindoles: stobadine dipalmitate and SMe1.2HCl.

The aim of this study was to evaluate the therapeutic potential of oxidative stress (OS) reduction by using pyridoindole (PI) antioxidants in adjuvant arthritis (AA). The substances tested were stobadine dipalmitate (STB) and SMe1. AA was used as animal model. The experiments included healthy animals, control arthritic animals and arthritic animals with administration of PI in the oral daily dose of 15 mg/kg b.m during 28 experimental days. The rats were sacrificed on day 28. Clinical and biochemical parameters were determined. The effect of PI administration was evaluated on the basis of the following parameters: (a) arthritis (volume of hind paws - HPW, change of animal body mass - CBM), (b) OS (chemiluminescence of whole blood - CWB, levels of thiobarbituric acid reacting substance - TBARS and of HNE- and MDA-protein adducts in plasma and activity of gamma-glutamyltransferase (GGT) in hind paw joint homogenates). The PI studied significantly increased the CBM of animals and corrected the HPW. STB also significantly decreased the activity of GGT in joint homogenates. SMe1 was more effective in decreasing plasmatic TBARS levels, but STB was more effective in reducing plasmatic HNE- and MDA-protein adducts. The assay for HNE- and MDA-adducts in plasma as a function of time was applied for the first time in AA. STB markedly decreased spontaneous and PMA-stimulated CWB and reduced neutrophil count. In summary, STB was more effective than SMe1 in reducing OS in AA. Our results showed that the reduction of OS in arthritis also corrected the clinical manifestations of the disease.

Alterations in adipocyte glucose transporter GLUT4 and circulating adiponectin and visfatin in rat adjuvant induced arthritis.

UNLABELLED: Rheumatoid arthritis in humans brings about impaired insulin sensitivity and glucose tolerance. Since adipose tissue plays a role in glucose homeostasis, we evaluated the size of adipocytes, the amount of glucose transporter type 4 (GLUT4) in adipocyte plasma membranes, and circulating insulin, glucose, and adipokines affecting glucose metabolism, resistin, adiponectin and visfatin during experimental adjuvant arthritis (AA) in male Lewis rats. AA was induced by a single injection of complete Freund's adjuvans. Adipocyte diameter was assessed microscopically, GLUT4 was measured by Western blotting. Plasma insulin, adiponectin, visfatin were quantitated by RIA, and resistin by ELISA. Arthritic rats showed cachexia, reduced adipocyte size, and downregulated membrane GLUT4 (4065 +/- 962 vs. 9911 +/- 680 arb. units of optic density, p < 0.01), reduced plasma adiponectin (1.956 +/- 0.10 vs. 3.16 +/- 0.22 microg/ml, p < 0.001), and enhanced visfatin (1.84 +/- 1.05 vs. 1.24 +/- 0.1 ng/ml, p < 0.01). Plasma glucose and insulin were unaltered, as were the resistin levels. CONCLUSION: AA induced cachexia results in reduction of adipocyte size, and paradoxically also in downregulation of GLUT4 in adipocyte membranes. This is supposed to be functionally related to the reduced adiponectin levels. The upregulated visfatin in rat arthritis is a novel finding, and it confirms its role in autoimmunity across the species.

Treatment of rat adjuvant arthritis with flavonoid (Detralex), methotrexate, and their combination.

In both adjuvant arthritis and rheumatoid arthritis, edema and inflammation appear in synovial joints. Edema or effusion reflects an imbalance in lymph dynamics. Purified micronized flavonoid fraction is mainly used in the treatment of chronic venous insufficiency. This compound improves lymphatic drainage with a significant increase in lymphatic flow and lymphatic pulsality. It is suggested that the beneficial effect of purified micronized flavonoid fraction may be involved in the treatment of adjuvant arthritis in rats. In this study treatment of adjuvant arthritis in rats with Detralex, methotrexate, and their combination were evaluated. Groups of rats with adjuvant arthritis were treated with methotrexate (0.6 mg/kg/week), Detralex (20 mg/kg/day), and their combination for 50 days from adjuvant application. Hind paw swelling, arthrogram scores, serum albumin level, serum nitrite/nitrate concentrations, and whole-body mineral density were evaluated as markers of inflammation and destructive changes associated with arthritis. Long-term prophylactic treatment with low-dose methotrexate significantly inhibited the markers of both inflammation and arthritis. Detralex administered alone slightly decreased both the hind paw swelling and the arthritic score. Other inflammatory and arthritic markers were not significantly influenced. However, Detralex combined with methotrexate markedly potentiated the beneficial effects of methotrexate, which resulted in a more significant reduction in hind paw swelling, arthritic scores, and serum concentrations of nitrite/nitrate. Interestingly, the arthritis-induced decrease of bone mineral density in AA rats was significantly lower only in the group treated with the combination of Detralex and methotrexate. Our results indicate that Detralex increased the therapeutic efficacy of methotrexate basal treatment in AA. We suggest that this may be related to the beneficial effect of Detralex on microcirculation, especially on venules and lymphatic vessels.

Methotrexate treatment ameliorated testicular suppression and anorexia related leptin reduction in rats with adjuvant arthritis.

Methotrexate (MTX) has been frequently used in the treatment of rheumatoid arthritis (RA). However, its action on arthritis associated male hypogonadism, or anorexia related low leptin production has not yet been studied. The well-established model of human RA is rat adjuvant-induced arthritis (AA). In the present series we aimed at the evaluation of the effects of MTX on AA induced inflammatory parameters, testosterone suppression, and anorexia associated lowered leptin release. AA was induced in male Lewis rats by intradermal injection of heat killed Mycobacterium butyricum in incomplete Freund's adjuvant in the base of the tail. Arthritic rats were treated with two doses of MTX: 0.3 and 0.5 mg/kg twice a week orally for the period of 28 days. The evaluated parameters were body mass, hind-paw swelling, arthrogram scores, serum albumin, total testosterone and leptin on days 14, 21 and 28 of AA. MTX treatment ameliorated all parameters studied dose dependently. Higher dose of MTX induced a significant reduction in the hind-paw swelling, arthritic score, and an increase in serum albumin in all examined time intervals of AA. This dose also significantly improved the suppressed testosterone and leptin levels found in arthritic rats. Prophylactic MTX treatment of rats with AA improved all inflammatory and arthritic parameters studied indicating its clear anti-inflammatory effects. The significant improvement of testosterone and leptin shows beneficial effects of MTX on reproduction and anorexia related leptin reduction during chronic AA.

Effects of purified micronized flavonoid fraction (Detralex) on prophylactic treatment of adjuvant arthritis with methotrexate in rats.

BACKGROUND: In both adjuvant arthritis and rheumatoid arthritis, edema and inflammation appear in synovial joints. Edema or effusion reflects an imbalance in lymph dynamics. Purified micronized flavonoid fraction is mainly used in the treatment of chronic venous insufficiency. This compound improves lymphatic drainage with a signicant increase in lymphatic flow and lymphatic pulsality. It is suggested that the beneficial effect of purified micronized flavonoid fraction may be involved in the treatment of adjuvant arthritis in rats. OBJECTIVES: To evaluate the effect of Detralex on methotrexate prophylactic treatment of adjuvant arthritis in rats. METHODS: Groups of rats with adjuvant arthritis were treated with methotrexate (0.6 mg/kg/week), Detralex (20 mg/kg/day) and their combination for 50 days from adjuvant application. Hind paw swelling, arthrogram scores, serum albumin level, serum nitrite/nitrate concentrations and whole body mineral density were evaluated as markers of inflammation and destructive changes associated with arthritis. RESULTS: Long-term prophylactic treatment with low dose methotrexate significantly inhibited the markers of both inflammation and arthritis. Detralex administered alone slightly decreased both the hind paw swelling and the arthritic score. Other inflammatory and arthritic markers were not significantly influenced. However, Detralex combined with methotrexate markedly potentiated the beneficial effects of methotrexate, which resulted in a more significant reduction in hind paw swelling, arthritic scores, and serum concentrations of nitrite/nitrate. Interestingly, the arthritis-induced decrease of BMD in AA rats was significantly lower only in the group treated with the combination of Detralex+methotrexate. CONCLUSION: Detralex increased the therapeutic efficacy of methotrexate basal treatment in AA. We suggest that this may be related to the beneficial effect of Detralex on microcirculation, especially on venules and lymphatic vessels.

Combination treatment of rat adjuvant-induced arthritis with methotrexate, probiotic bacteria Enterococcus faecium, and selenium.

The effects of the probiotic bacteria Enterococcus faecium (EF) and selenium were studied on methotrexate (MTX) treatment in rats with adjuvant arthritis. Arthritic rats were treated orally with the following substances: lyophilized EF (15 mg/kg/day, 5 days a week), sodium selenite pentahydrate (SSe; 0.050 mg/kg containing 0.015 mg/kg selenium, 5 days a week), MTX (0.6 mg/kg/week), and their combinations for the period of 50 days from adjuvant application. Levels of serum albumin, serum nitrite/nitrate concentrations, hind paw swelling, arthrogram scores, whole-body bone mineral density (BMD), and bone erosions were evaluated as markers of inflammation and destructive changes associated with arthritis. Long-term preventive treatment with low-dose MTX significantly inhibited the markers of both inflammation and arthritis. EF or SSe when administered singly or in combination had no significant effect on the given parameters in arthritic rats. EF, but not SSe, potentiated the beneficial effects of MTX, which resulted in a more significant reduction of hind paw swelling, arthrogram scores, and whole-body BMD decrease. EF also had a tendency to improve the effect of MTX on serum albumin and nitrite/nitrate concentrations. Our results indicate that EF may increase the preventive effect of MTX treatment in rat adjuvant arthritis by improving its anti-inflammatory and antiarthritic effects.

The effects of Enterococcus faecium and selenium on methotrexate treatment in rat adjuvant-induced arthritis.

The effects of probiotic bacteria Enterococcus faecium (EF) and selenium were studied on methotrexate (MTX) treatment in rats with adjuvant arthritis (AA). Arthritic rats were preventive treated orally with the following substances: lyophilized EF (15mg/kg/day, 5 days a week); sodium selenite pentahydrate (SSe, 0.050mg/kg containing 0.015 mg/kg selenium, 5 days a week); MTX (0.6 mg/kg/week), and their combinations for the period of 50 days from adjuvant application. Levels of serum albumin, serum nitrite/nitrate concentrations, hind paw swelling, arthrogram scores, whole body bone mineral density (BMD), and bone erosions were evaluated as markers of inflammation and destructive changes associated with arthritis. Long-term preventive treatment with low-dose MTX significantly inhibited the markers of both inflammation and arthritis. EF or SSe when administered singly or in combination had no significant effect on given parameters in arthritic rats. EF but not SSe potentiated the beneficial effects of MTX, which resulted in a more significant reduction of hind paw swelling, arthrogram scores and whole body BMD decrease. EF had a tendency to improve also the effect of MTX on serum albumin and nitrite/nitrate concentrations. Our results indicate that EF may increase the preventive effect of MTX treatment in rat AA by improving its anti-inflammatory and anti-arthritic effects.

Effect of immunostimulatory ribomunyl on the preventive treatment of rat adjuvant arthritis with cyclosporine and methotrexate.

OBJECTIVE: To study the effects of ribomunyl, an oral ribosomal immunostimulant frequently used to prevent recurrent oropharyngeal and bronchopulmonary infections in children and adults, on adjuvant arthritis as well as its effect on methotrexate and cyclosporine treatment. METHODS: Rats with adjuvant induced arthritis were preventively treated orally with the following drugs: cyclosporin A (CSA, 2.5 mg/kg/day); ribomunyl (RIB, 25 mg/kg/day, 4 days a week); methotrexate (MTX, 0.6 mg/kg/week), and the combinations CSA + RIB, MTX + RIB, CSA + MTX, CSA + MTX + RIB for the period of 50 days from adjuvant application. Levels of serum albumin, serum nitrite/nitrate concentrations, hind paw swelling, arthrograms, and bone destruction were measured in rats as variables of the inflammation and destructive arthritis associated changes. RESULTS: Preventive treatment with low doses of CSA and MTX significantly inhibited both markers of inflammation and arthritis. The combination CSA + MTX was more effective on all evaluated measures than any of its components alone. RIB alone improved arthrogram scores and decreased serum nitrite/nitrate concentrations in arthritic rats. The combination of RIB with the low dose of CSA or MTX enhanced the beneficial effects of these drugs. The best preventive effect was observed with the combination of 3 agents, CSA + MTX + RIB. CONCLUSION: Our results show ribomunyl to have the potential to improve some inflammation and arthritis associated changes in rat adjuvant arthritis and to enhance the preventive effect of MTX and CSA and their combination.