Homoeopathic drug dilutions of Thuja occidentalis attenuate complete Freund's adjuvant-induced arthritis in Wistar rats

Context: Thuja occidentalis is prescribed in Homoeopathy in treating rheumatoid arthritis. We speculated the anti-arthritic mechanism of Homoeopathic dilutions of Thuja occidentalis against the complete Freund's adjuvant (CFA)-induced arthritis in rats. Materials and Methods: Arthritis was induced ( n = 28) by subplantar injection of 0.1 ml CFA in the right hind paw of rats. The oral dose of crude Thuja occidentalis was 30 mg/kg/b. i. d and that of Homoeopathic dilutions was 0.1 ml/b. i. d. Orally administered diclofenac at 5 mg/kg/day served as a standard. The treatments continued for 24 days. The severity of arthritis was determined weekly as rise in paw volume, mechanical allodynia and changes in body weight. On the 25 th day, X-ray imaging of the arthritic paws was recorded, and the biopsy samples extracted from the paws were subjected to the estimation of pro-inflammatory cytokines and histological evaluations. Results: Thuja occidentalis Homoeopathic dilutions and its crude form protected rats against the CFA-induced arthritic lesions. The mother tincture, 6cH, 30cH and 200cH dilutions of Thuja occidentalis significantly reduced the CFA-induced rise in paw volume, reduced the mechanical allodynia and also reduced the levels of interleukin (IL) IL-1, IL-6 and tumour necrosis factor alpha in paw tissue. CFA-induced articular changes, oedema, cellular infiltrations and cartilage damage were reduced by Thuja occidentalis dilutions. The radiological images indicated that Thuja occidentalis treatment reduced the CFA-induced joint swelling, bone erosion and joint space narrowing. Conclusion: Our findings substantiate the anti-arthritic effects of Thuja occidentalis Homoeopathic dilutions against CFA-induced arthritis and indicate that Homoeopathic dilutions of Thuja occidentalis, particularly 6cH dilution, exert more potent anti-arthritic effects than its crude form.