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.