Repercussions of adjuvant-induced arthritis on body composition, soleus muscle, and heart muscle of rats

Orchiectomy but not adjuvant-induced arthritis induces structural modifications in rat aortas

Purpose: This study aimed to verify whether Adjuvant-Induced Arthritis (AIA) and/or Orchiectomy (ORX) modify the expression of the Nox1, Nox2 and Nox4 isoforms, the endothelial function or the structure of rat aortas. Methods: Sixty-three Wistar rats were distributed into four groups: 1) Control; 2) ORX; 3) AIA; 4) Orchiectomy plus to Arthritis-induction (ORX/AIA). Thus, 21 days after the onset of AIA (by intradermal injection of Mycobacterium tuberculosis), the presence of Nox1, Nox2 and Nox4, the acetylcholine (ACh)-induced relaxation and the media layer thickness were assessed in the aorta taken from these animals. Results: The Nox1, Nox2 and Nox4 were immunostained in intima, media and adventitia layers of aortas taken from all studied groups and AIA apparently increased this immunostaining. These modifications of Nox1, Nox2 or Nox4 expression, however, were not confirmed by Western blotting. In addition, neither AIA nor ORX changed the endothelial function, but ORX increased the media layer thickness in the studied aortas. Conclusion: The present study showed weak clues of increased expression of Nox1, Nox2 and Nox4 as a result of AIA, as well as of Nox1 reduction caused by ORX. In addition, the endothelial function was not modified in the aortas of these animals by both AIA and/or ORX. On the other hand, ORX increased significantly the aorta media layer thickness in the studied animals, which was apparently mitigated by AIA.

Evaluating the anti-arthritic potential of walnut (Juglans regia L.) in FCA induced Sprague Dawley rats

Rheumatoid arthritis (RA) is an autoimmune progressive disease, associated with many pathophysiological consequences. Owing to the adverse effects and higher costs of pharmaceuticals, people are now looking for complementary and alternative remedies. In this milieu, the present study was designed to explore the therapeutic potential of walnuts against FCA-induced arthritis in rat models. Purposely, 50 Sprague Dawley rats were housed in a well-ventilated animal room and separated into 5 groups of 10 rats each. The rats were categorized as G₀ (negative control), G₁ (positive control, i.e., FCA induced untreated arthritic rats), G₂ (arthritic rats treated with MTX), G₃ (arthritic rats treated with walnut feed), and G₄ (arthritic rats treated with walnut extract), with an efficacy trial lasting for 42 days. The physical analysis explicated that paw swelling was significantly improved by 10%-12.8% in treatment groups after the intervention when compared with positive control. Moreover, biochemical analyses revealed significantly lower levels of ESR, CRP, and RF in rats treated with walnut-based interventions when compared to positive control. ESR values were decreased by 62.4% and 69.92% in G₃ and G₄ , whereas CRP levels were improved by 56.20% and 77.78% in G₃ and G₄ when compared with G₁ . Likewise, RF values decreased in G₂ , G₃ , and G₄ by 64.71%, 55.88%, and 69.24%, respectively when compared to G₁ . The histological examination demonstrated the potential role of walnut-based interventions in reducing the severity of disease by decreasing cell infiltration, bone erosion, and paw inflammation. Meanwhile, the gene expression analysis revealed that walnut-based interventions protected the paw joints from damage by downregulating the RANKL-OPG pathway. Conclusively, walnut feed and extract may serve as potent anti-arthritic interventions with no side effects. PRACTICAL APPLICATIONS: Plant-based therapeutics are effective in the prevention and management of various chronic diseases. The current research explored the anti-arthritic potential of walnuts. Walnut feed and extract effectively reduced the serum arthritic biomarkers as well as downregulated the genes involved in bone destruction. Thus, the inclusion of dietary ingredients having therapeutic potential such as walnuts may be synchronized in clinical practices to ameliorate arthritis.

Animal models to study pathogenesis and treatments of cardiac disorders in rheumatoid arthritis: Advances and challenges for clinical translation

Although cardiac diseases such as acute myocardial infarction, heart failure and arrhythmias are the leading cause of cardiovascular complications in rheumatoid arthritis (RA), their pathogenesis is far from being understood and optimal therapeutic options to treat specifically these disorders in RA are lacking. Preclinical studies on animal models of arthritis can help to decipher the complex link between arthritis and the heart, and to identify critical pathways and novel therapeutic targets. This review presented the available data on cardiac disorders in animal models of RA, as well as the current knowledge on pathophysiology and pharmacology of these disorders. Future directions for translational studies in a cardiorheumatic perspective are proposed.