In vitro radical scavenging and in vivo antiarthritic effects of Spondias mombin (L.) stem bark

Rheumatoid arthritis (RA) is a systemic autoimmune disorder that affects about 1% of the population globally. Numerous conventional medications are available for the management of RA. However, their usage is limited due to the associated side effects. Spondias mombin is a member of the Anacardiaceae family known for its anti-arthritic effects. This study aimed to evaluate the anti-arthritic activity of S. mombin (L.) stem bark in RA. Radical scavenging activity was determined using DPPH assay. The anti-inflammatory effect was determined using protease inhibition and formaldehyde-induced arthritis models. S. mombin aqueous fraction (SMAF) exhibited a significant (p<0.0001) radical scavenging effect (IC50 of 57.87 µg/mL) over the S. mombin methanol extract (SMME) and S. mombin chloroform fraction (SMCF) when compared to the sham control. SMAF at 500 µg/mL significantly (p<0.05) inhibited (56.89 ± 2.02%) the effect of protease when compared to the sham control. SMME significantly (p<0.001) reduced inflammation in rat paws when compared to the control with peak effects seen at the dose of 50 mg/kg body weight. The result of the study has revealed that the stem bark has radical scavenging and anti-inflammatory effects.