Therapeutic effects of Caragana pruinosa Kom. roots extract on type II collagen-induced arthritis in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Caragana pruinosa Kom. is a deciduous shrub belonging to the genus of Caragana (Leguminosae), and Caragana plants exhibit a wide range of interesting pharmacological properties including anti-inflammatory, analgesic, and anti-arthritis activity, etc.

AIM OF THE STUDY: This study was aimed to investigate the anti-arthritic effect of 80% EtOH extract from the roots of C. pruinosa (ERCP) on arthritis and explore the potential pharmacological mechanism.

MATERIALS AND METHODS: After collagen induced arthritis (CIA) were established in rats, the animals were orally administered with ERCP (130, 260 and 520mg/kg) for 30 days. During the treatment, the rats' body weights, arthritis indices and paw volumes were measured every 5 days. Subsequently, rats' blood samples were collected to determine TNF-α, IL-1β, IL-6, IL-10, and C-reactive protein (CRP) contents in serum. Then, rats were sacrificed and the hind paws and knee joints were collected for histopathological examination.

RESULTS: Our results indicated that ERCP significantly suppressed the inflammatory reactions and destructions in joints and synovial tissues. ERCP inhibited the paw swelling and arthritis index in CIA rats. Additionally, it decreased the levels of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and CRP, whereas increased that of IL-10.

CONCLUSION: Our results suggested ERCP has significant anti-arthritic effect on CIA rats, and the pharmacological mechanisms are related to the down-regulation of TNF-α, IL-1β, IL-6 and CRP and the up-regulation of IL-10.