Potential Anti-Inflammatory Effects of Ethanol Extract of <i>Caryota urens</i> Lour Fruits on Freund's Complete Adjuvant-Induced Rheumatoid Arthritis in Mice

Abstract

Caryota urens L. is a widely cultivated plant often employed in traditional medicine for the treatment of various conditions such as  arthritis, gastritis, skin disorders, blisters, and pain relief. Despite its common use, the anti-inflammatory effect of C. urens fruit extract  remains unproven and undocumented in scientific literature. This study assessed the anti-inflammatory effects of ethanol extract of C.  urensfruit and provide scientific evidence for the anti-arthritis herbal remedy. A rheumatoid arthritis model was induced by injecting  complete Freund's adjuvant (0.1 mL) into the right hind paw of mice, and three doses of ethanol extract of C. urens fruit (100, 200, and 300 mg/kg body weight) were administered for treatment. The severity of arthritis was evaluated through joint circumference and arthritis  scores, as well as hematological and biochemical parameters (red blood cells, white blood cells, erythrocyte sedimentation rate, alkaline  phosphate, C-reactive protein, and rheumatoid factor). The inflammatory and anti-inflammatory cytokines (TNF-α, INF-γ, IL-1β, IL-6, and  IL-10) and histological changes in the joints were also examined. The results demonstrated a significant reduction in paw volume and  arthritis scores with all three doses of the extract. Furthermore, the C. urens fruit extract exhibited the ability to modulate the interplay of  inflammatory cytokines and mitigate the histological alterations induced by Freund's adjuvant. The effectiveness of the high dose (300  mg/kg body weight) was comparable to the Mobic (0.2 mg/kg body weight). In conclusion, this study elucidates the potential of C. urens  fruit extract in arthritis treatment, providing a scientific justification for it traditional use as a remedy for arthritis management.