Anti-rheumatoid arthritis and vascular endothelial improvement by Derris scandens Roxb. Benth. in adjuvant-induced arthritis in rats

Derris scandens stem (DS), a Thai medicinal plant traditionally used to treat musculoskeletal pain, has shown some cardiovascular properties [ 1 ] [ 2 ]. However, its mechanisms and impact on cardiovascular disorders related to arthritis remain unexplored. We aimed to explore the impact of DS on endothelial dysfunction and traditional cardiovascular risk factors in a rat model of adjuvant-induced arthritis (AIA). From the onset of arthritis symptoms, DS (200 mg/kg/day, orally), methotrexate (1 mg/kg/week, subcutaneously), or their combination was administered for 21 days, with daily monitoring of body weight and arthritis scores. At the end of the treatment period, electrocardiography and blood pressure were measured in anesthetized rats. Endothelial function was evaluated in isolated pulmonary arteries (PA) and aortae through acetylcholine-induced relaxation. Plasma cytokine levels and leukocyte populations in peripheral blood and PA were measured. Direct DS-induced relaxation was also assessed in healthy rats. Results showed that direct exposure to DS induced greater relaxation in the PA (Emax=90%) than in the aorta (Emax=38%). Similar to methotrexate, DS significantly reduced arthritis severity compared to untreated AIA rats. In AIA rats, DS notably improved endothelial function in both the PA and aorta. Concurrently with the decrease in TNF-α and IL-1β plasma levels, PA-infiltrated leukocyte populations, particularly neutrophils, were reduced after DS treatment. Co-administration with methotrexate diminished these vascular benefits. In summary, DS alleviates arthritis severity and enhances endothelial function in AIA rats by reducing leukocyte populations and cytokine levels. However, caution should be taken when combining DS with methotrexate. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany