The purpose of this study was to evaluate the effect of β-(1,3/1,6)-D: -glucan isolated from Pleurotus ostreatus (β-glucan-PO) on prophylactic treatment of adjuvant arthritis (AA) with methotrexate (MTX) in rats. Groups of rats with AA were treated with methotrexate (1 mg/kg/week), β-glucan-PO (1 mg/kg every second day) or their combination for the period of 28 days from adjuvant application. Body mass, hind paw swelling, arthrogram scores and a level of serum albumin were measured as markers of inflammation and arthritis. Treatment with low dose of MTX significantly inhibited the markers of both inflammation and arthritis. MTX and its combination with β-glucan-PO significantly increased body mass of arthritic rats. β-glucan-PO administered alone significantly decreased both the hind paw swelling and arthritic score. In combination with MTX, β-glucan-PO markedly potentiated the beneficial effects of MTX, which resulted in a more significant reduction of hind paw swelling and arthritic scores. The concentration of albumin in the serum of arthritic controls was significantly lower than in healthy controls. Both MTX alone and the combination treatment with MTX + β-glucan-PO significantly inhibited the decrease in serum albumin. β-Glucan-PO increased the treatment efficacy of basal treatment of AA with MTX.

Systemic sclerosis is a generalized disease characterized mainly by the accumulation of collagen in the skin and internal organs. The aim of our study was to determine the amount of collagen cross-link pyridinoline (Pyd) in a variety of fibrotic tissues (skin, fascia, endocardium, bladder) from an autopsy patient with diffuse systemic sclerosis, and to compare these with normal tissues from the same patient. Mean concentrations of Pyd in the fibrotic skin samples (66 mmol/mol collagen) were more than two-times greater than those in the uninvolved normal samples (27 mmol/mol collagen). The increase of Pyd in the endocardium, fascia, and bladder was also markedly higher (1.41 x, 1.26 x and 2.64 x higher than normal samples). The increased deposition of collagen in systemic sclerosis is accompanied by a significantly increased amount of Pyd in the collagen of fibrotic tissues.

A certain relationship was observed between the gastrointestinal system, arthritis and immune system. Patients with rheumatoid arthritis have an altered microflora composition and disturbed intestinal defensive barrier. Effect of probiotic bacteria (Colinfant; COL) with known favorable effect on intestinal microflora was determined on the methotrexate (MTX) treatment of adjuvant arthritis. Rats with adjuvant arthritis were administered methotrexate 0.5 mg/kg body mass 2-times weekly per os, COL 1 mL/kg body mass every second day per os, and a combination of MTX+COL for a period of 28 d from the immunization. Levels of serum albumin, body mass, changes in hind paw swelling, and arthrogram score were estimated in rats as variables of inflammation and destructive arthritis-associated changes. Treatment with MTX, as well as with the combination treatment with MTX+COL significantly inhibited both inflammation and destructive arthritis-associated changes. The combination treatment inhibited both the hind paw swelling and arthrogram score more remarkably than MTX alone; on the other hand, the difference between combination treatment and MTX alone was not significant. Treatment with COL alone had no effect on adjuvant arthritis in rats. Colinfant can increase the preventive effect of MTX treatment in rat adjuvant arthritis by improving its antiarthritic effects.

Abstract. 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 µg/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.

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.