Effect of auranofin on plasma fibronectin, C reactive protein, and albumin levels in arthritic rats

The effects of orally administered Bacillus coagulans and inulin on prevention and progression of rheumatoid arthritis in rats

BACKGROUND

Probiotics have been considered as an approach to addressing the consequences of different inflammatory disorders. The spore-forming probiotic strain Bacillus coagulans has demonstrated anti-inflammatory and immune-modulating effects in both animals and humans. The prebiotic inulin also potentially affects the immune system as a result of the change in the composition or fermentation profile of the gastrointestinal microbiota.

OBJECTIVE

In the present study, an in vivo model was conducted to investigate the possible influences of probiotic B. coagulans and prebiotic inulin, both in combination and/or separately, on the downregulation of immune responses and the progression of rheumatoid arthritis (RA), using arthritis-induced rat model.

DESIGN

Forty-eight healthy male Wistar rats were randomly categorized into six experimental groups as follows: 1) control: normal healthy rats fed with standard diet, 2) disease control (RA): arthritis-induced rats fed with standard diet, 3) prebiotic (PRE): RA+ 5% w/w long-chain inulin, 4) probiotic (PRO): RA+ 10(9) spores/day B. coagulans by orogastric gavage, 5) synbiotic (SYN): RA+ 5% w/w long-chain inulin and 10(9) spores/day B. coagulans, and 6) treatment control: (INDO): RA+ 3 mg/kg/day indomethacin by orogastric gavage. Feeding with the listed diets started on day 0 and continued to the end of study. On day 14, rats were injected with complete Freund's adjuvant (CFA) to induce arthritis. Arthritis activity was evaluated by the biochemical parameters and paw thickness. Biochemical assay for fibrinogen (Fn), serum amyloid A (SAA), and TNF-α and alpha-1-acid glycoprotein (α1AGp) was performed on day 21, 28, and 35 (7, 14 and 21 days post RA induction), respectively.

RESULTS

Pretreatment with PRE, PRO, and SYN diets significantly inhibits SAA and Fn production in arthritic rats (P < 0.001). A significant decrease in the production of pro-inflammatory cytokines, such as TNF-α, was seen in the PRE, PRO, and SYN groups (P < 0.001), which was similar to the anti-inflammatory effect of indomethacin. Furthermore, no significant anti-inflammatory effects were observed following different treatments using α1 AGp as an RA indicator. Pretreatment with all supplied diets significantly inhibited the development of paw swelling induced by CFA (P < 0.001).

CONCLUSION

The results of this study indicate that the oral intake of probiotic B. coagulans and prebiotic inulin can improve the biochemical and clinical parameters of induced RA in rat.

Pharmacological studies of diacerein in animal models of inflammation, arthritis and bone resorption

Diacerein has proved to be effective in the treatment of osteoarthritis. We investigated the effects of diacerein in animal models of carrageenin-, zymosan-, or dextran-induced paw edema and adjuvant-induced arthritis and in ovariectomized rats. In acute inflammatory models, unlike classical nonsteroidal anti-inflammatory drugs such as naproxen and ibuprofen, diacerein inhibited the rat paw edema induced by various agents. In the adjuvant-induced arthritic rats, diacerein at 100 mg/kg/day significantly suppressed the paw edema and the increase in serum mucoprotein. Addition of 3 mg/kg/day naproxen to each diacerein (3, 10, 30 mg/kg/day) dose resulted in significantly greater anti-inflammatory activity than with naproxen alone. In the ovariectomized rats, diacerein (10, 100 mg/kg/day) also significantly prevented bone loss and reduced the serum alkaline phosphatase and decreased the excretion of urinary hydroxyproline. In addition, rhein (10, 30 microM) inhibited calcium release from mouse calvaria induced by interleukin-1 beta, prostaglandin E(2) and parathyroid hormone 1-34 human fragment. These findings indicate that diacerein is a novel anti-inflammatory drug with pharmacological properties different from those of classical nonsteroidal anti-inflammatory drugs and support the clinical investigation of the use of combination therapy with diacerein and nonsteroidal anti-inflammatory drugs in patients with not only osteoarthritis but also rheumatoid arthritis.

Freund's complete adjuvant induces ornithine decarboxylase activity in the central nervous system of male rats and triggers the release of pituitary hormones

In male rats, inoculation of Freund's complete adjuvant (FCA, 0.5 mg/rat of Mycobacterium butyricum in paraffin oil) induced high levels of ornithine decarboxylase (ODC) in the hypothalamus and pituitary gland (285% and 245% of controls, respectively, within 12 h to 2 days). ODC activity also was altered in the cerebellum and left neocortex, but not in the right neocortex. This activity reflected a dynamic equilibrium which is influenced by ODC synthesis, degradation, activation, etc. The circadian rhythms of pituitary ODC activity and plasma prolactin level, 3-4 days after FCA, showed that enhancement of enzymatic activity during the dark phase correlated with a marked release of prolactin (Prl). During this early period after FCA, changes in plasma levels of other pituitary hormones were not significant or were less important. Pretreatment with bromocriptine microcapsules inhibited both basal and FCA-induced pituitary ODC activity, as well as Prl secretion. Further, significant increases in plasma luteinizing hormone and adrenocorticotropic hormone were noted from days 4 and 8, respectively, and onwards. Finally, a phase of reduced corticosterone secretion occurred during the latency period. This study shows that FCA influences central nervous system pathways and supports the idea that endogenous Prl is involved in some early events which lead to the development of adjuvant arthritis.

Differential effects of anti-arthritic agents on subnormal plasma iron levels in adjuvant arthritic rats

Nonsteroidal anti-inflammatory drugs (NSAID's) and other antirheumatic compounds such as disease modifying antirheumatic drugs (DMARD's), immunosuppressives and glucocorticoids were tested to determine if daily medication for two weeks could elevate subnormal levels of plasma iron in adjuvant-arthritic (AA) rats. Aspirin, indomethacin, ibuprofen and phenylbutazone were chosen as representative carboxylic acids and pyrazole NSAID's. Although NSAID's at all doses significantly reduced noninjected paw swelling, no NSAID significantly enhanced subnormal plasma iron levels in AA rats. In contrast, the standard DMARD's auranofin and gold sodium thiomalate, as well as the glucocorticoid, dexamethasone and the immunosuppressives, methotrexate and cyclosporin-A all significantly restored plasma iron levels 28 to 100 percent. Plasma iron depression, a parameter of the acute phase response probably under regulation by pro-inflammatory cytokines, is not reversed by NSAID treatment. This appears to be a useful method for distinguishing NSAID's from other anti-arthritic compounds.