Therapeutic effects of extracts from Radix Toddaliae Asiaticae on collagen-induced arthritis in Balb/c mice

Aim of the study

Radix Toddaliae Asiaticae (RTA), also named “Sanbaibang”, is the dry root bark of Toddalia asiatica (L.) Lam. and has long been used as a traditional ethnic Chinese medicine for its considerable activity to alleviate pain and inflammation for patients suffering from rheumatism. It contains coumarin, alkaloids, triterpenes and volatile oils. Information regarding the anti-arthritis activity of RTA in vivo or in vitro is limited yet. In the present study, the aim is to investigate the therapeutic potential and underlying mechanisms of the ethyl alcohol extract (EtOH) and ethyl acetate fraction (EtOAc) from RTA on collagen II-induced arthritis (CIA) in mice.

Materials and methods

CIA animal model was performed by subcutaneous injection of type II bovine collagen (CII) on the 1st day and the 14th day of the experiment. Ethyl alcohol extract (542.8, 271.4, 135.7 mg/kg), ethyl acetate fraction (260.8, 130.4, 65.2 mg/kg) was orally administrated from the second antigen immunization for 3 weeks. Progression of edema of paws and knee joints was measured using a vernier caliper every 3 days from the 10th day after the first injection to the end of the experiment. The spleen index was measured and the knee joint changes were observed by pathological sections. ELISA was used to measure cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6) and interleukin-10 (IL-10) in mice serum according to the manufacturer’s instructions.

Results

Administration of ethyl alcohol extract and ethyl acetate fraction remarkably reduced paws and joints swelling and decreased the spleen indexes. Histopathological examination demonstrated that RTA effectively protected bone and cartilage of knee joint from erosion, lesion and deformation versus those from the control group. Besides, the concentration of cytokines like TNF-α, IL-1β, IL-6 were significantly lower than the ones from the control group respectively, while cytokine like IL-10 was remarkably higher compare with the control group.

Conclusion

In this present study, it is demonstrated that administration of RTA has potential and therapeutic effect on CIA. The data suggests that RTA could have a contributory ethno-pharmacological role in improved management of RA patients.