Aim: The present study was designed to investigate the effect of ellagic acid hydroxypropyl-β-cyclodextrin inclusion complex (EAHβCD) in adjuvant-induced arthritis in rats.

Methods: Adjuvant arthritis (AA) was induced by single subplanter injection of 0.1 ml Freund's complete adjuvant (FCA) into foot pads of left hind paw of Wistar rats. Thirty six healthy male rats were randomly divided into six groups with six rats each. From day 0 after FCA injection, EAHβCD group (10 mg/kg and 20 mg/kg), ellagic acid group (10 mg/kg) and standard diclofenac group (5mg/kg) were administered by oral gavage for 28 consecutive days. The disease progression was examined by analysis of arthritis score, paw oedema volume, body weight, joint diameter, index of thymus and spleen, locomotor function, hyperalgesia and histological changes in joints. Further serum levels of nitric oxide (NO), glutathione (GSH), superoxide dismutase (SOD), IL-6 and TNF-α were evaluated.

Results: Subplanter injection of FCA significantly (P < 0.001) increase in arthritis score, paw volume and joint diameter, while daily oral administration of EAHβCD (10 mg/kg and 20 mg/kg) significantly (P < 0.001) attenuated the disease progression and associated hyperalgesia. The macroscopic and histopathological evaluation of knee joints were also improved in EAHβCD and diclofenac treated AA rats. The serum levels of oxidative stress markers (NO, GSH and SOD) and cytokines (TNF-α and IL-6) were restore in treatment groups. 

Conclusion: The present study provides evidences of anti-arthritic potential of EAHβCD, which is mediated by attenuation of hyperalgesia, oxidative stress and pro-inflammatory cytokines (TNF-α and IL-6) in FCA-induced arthritic rats.