Novel therapies for rheumatoid arthritis

Amelioration of Rheumatoid Arthritis by Anacardium occidentale via Inhibition of Collagenase and Lysosomal Enzymes

Anacardium occidentale (cashew) has been used in the traditional system of medicine for curing many inflammatory disorders. The present study investigates the antiarthritic effects of cashew leaves extract using the rat model of FCA-induced rheumatoid arthritis. Arthritic rats were treated with 100 and 200 mg/kg b.w. ethanolic extract of cashew leaves. Animals were sacrificed at day 23, and before sacrificing the animals, gross pathological changes were observed. Histopathology of ankle joint was evaluated with hematoxylin and eosin staining, whereas the serum levels of C-reactive protein (CRP) were evaluated by the agglutination method. Inflammatory cells and other hematological parameters were assessed by employing an automated hemocytometer and chemistry analyzer. Rheumatoid factor (Rf) and lysosomal enzymes levels were determined in blood. Results indicated that A. occidentale significantly decreased the CPR levels, macroscopic arthritic score, and rheumatoid factor as compared to the diseased group. Histopathological evaluation showed significant attenuation in bone erosion, joint inflammation, and pannus formation by plant extract. Treatment with A. occidentale significantly suppressed the levels of acid phosphatase, β-galactosidase, β-glucuronidase, N-acetylglucosaminidase, and collagenase. Moreover, A. occidentale significantly raised the HB levels and RBCs counts which were found depleted in the diseased group. The raised counts of total leukocytes, platelets, neutrophils, lymphocytes, and monocytes were also significantly decreased by treatment with plant extract. Comparative analysis showed that higher dose of A. occidentale demonstrated superior amelioration of rheumatoid arthritis as compared to low dose. In conclusion, A. occidentale possesses significant antiarthritic potential, which may be attributed to the suppression of lysosomal enzymes and collagenase levels.

Advances in research on animal models of rheumatoid arthritis

At present, rheumatoid arthritis (RA) is considered a type of autoimmune disease. Its pathology is not certain, and effective drugs with less toxicity have not been established. The establishment and application of animal models are effective methods for RA research, especially using animal models similar to humans. Arthritis is more heterogeneous, and this is an important starting point when discussing animal models for arthritis. Animal models are instrumental in understanding the etiology and pathogenetic mechanisms of RA. Appropriate animal models should be selected according to experiments because they have different traits. Various methods have been applied to induce arthritis in animal experimental models, which have provided important insights into the etiopathogenetic mechanisms of human RA. This review was written to give a broad introduction of the current stage of RA model and hope to offer beneficial help for RA-related research.

Natural killer cells and their role in rheumatoid arthritis: friend or foe?

Rheumatoid arthritis (RA) is a long-term disease that leads to inflammation of the joints and surrounding tissues. Natural killer (NK) cells are an important part of the innate immune system and are responsible for the first line of defense against pathogens during the initial immune challenge before the adaptive immune system eventually eliminates the infectious burden. NK cells have the capacity to damage normal cells or through interaction with other cells such as dendritic cells, macrophages, and T cells cause autoimmune diseases, such as RA. NK cells isolated from the joints of patients with RA suggest that they may play a role in this disease. However, the involvement of NK cells in RA pathology is not fully elucidated. Both protective and detrimental roles of NK cells in RA have recently been reported. A better understanding of NK cells' role in RA might help to develop new therapeutic strategies for treatment of the RA or other autoimmune diseases. We have decided in this paper to focus on the NK cell biology, and attempt to bring the interested readership of this Journal up to date on the NK cell, specifically its possible relation to RA.

Anti-inflammatory effect of Sanshuibaihu decoction may be associated with nuclear factor-kappa B and p38 MAPK alpha in collagen-induced arthritis in rat

Sanshuibaihu decoction (SSBH) is an anti-arthritic Chinese herbal formula which has been used in the treatment of rheumatoid arthritis (RA) for many years. We herein aimed to confirm its anti-arthritic effect and explore the potential mechanism of action on collagen-induced arthritis (CIA) in rats. CIA was induced by immunizing 50 female Wistar rats with bovine type II collagen. 13 days following the immunization rats with CIA were treated with SSBH (50mg/kg), leflunomide (LEF) (10mg/kg) and physiological saline for 30 days, and rats without CIA were left untreated. After the treatment, paw edema was obviously improved in SSBH-treated rats, with the significant difference of arthritis score (F=6.032, P=0.006) observed between the three treated groups. In pathological observation, SSBH-treated rats showed a significant improvement of inflammatory infiltration, synovial hyperplasia, cartilage and bone destruction and joint fusion. After the treatment of SSBH, radiological score of knee (t=11.504, P=0.000) and ankle joints (t=9.250, P=0.000) was decreased significantly. In situ hybridization on joint tissue section indicated only slight synovial hyperblastosis and expression of NF-kappaB in SSBH-treated rats. Image analysis indicated a significant difference of means of integrated optical density (MIOD) (F=3.956, P=0.040) and means of stained area (MSA) (F=3.867, P=0.032) of NF-kappaB between the three treated groups. MIOD and MSA of SSBH-treated group were significantly lower vs control. Enzyme linked immunosorbent assay (ELISA) showed a significant difference (F=10.167, P=0.000) of the amount of p-p38 MAPKalpha in the three treated groups. The detected amount of p-p38 MAPKalpha in SSBH-treated group was significantly lower vs control. These results show SSBH has an inhibiting effect on CIA, which may be associated with NF-kappaB and p38 MAPKalpha.