Fumaric acid per se and in combination with methotrexate arrests inflammation via moderating inflammatory and oxidative stress biomarkers in arthritic rats.

Objective: Fumaric acid is a dicarboxylic acid that belongs to the phenolic class enriched in fruits and vegetables that are traditionally used for the treatment of various ailments. The research was planned to find out the anti-inflammatory and anti-arthritic activities of fumaric acid using in-vitro and in-vivo assays. Moreover, safety study was also done.

Materials and methods: The 0.1 ml complete Freund's adjuvant was injected in left hind paw in all Wistar rats except normal rats at day 1 to induced arthritis. The treatment with fumaric acid at 10, 20, 40, and fumaric acid 40 mg/kg together with methotrexate (MTX) was administered to immunized rats at 8th day via oral gavage and continued till 28th day though, MTX was administered as standard control.

Results: The fumaric acid notably (p < 0.0001) lessened the paw edema and arthritic scoring, reinstated body and immune organ weight, and oxidation status in treated rats. Fumaric acid notably restored altered C-reactive protein, rheumatoid factor, liver function tests, ESR, WBCs, RBCs and Hb levels in treated rats. The fumaric acid in combination noticeably (p < 0.01-0.0001) suppressed the expression of TNF- α, IL-6, IL-1β, NF-kβ, and COX-2, and over expressed IL-4, and IL-10 in contrast to other treated groups. Fumaric acid had presented a dose-dependent antioxidant, anti-inflammatory and anti-arthritic activities while notable activity exhibited by fumaric acid in combination with MTX. The fumaric acid exhibited non-significant clinical signs of toxicity and mortality in acute toxicity study. The LD50 was more than 2000 mg/kg.

Conclusion: Fumaric acid in combination can be used as disease-modifying anti-rheumatic drug but it will need extensive pre-clinical and clinical studies.