Isolation, structure modification, and anti-rheumatoid arthritis activity of isopimarane-type diterpenoids from Orthosiphon aristatus.

Orthosiphon aristatus is a well-known folkloric medicine and herb for Guangdong soup for the treatment of rheumatism in China. Eight isopimarane-type and migrated pimarane-type diterpenoids (1-8), including a new one with a rarely occurring α,ß-unsaturated diketone C-ring, were isolated from O. aristatus. Their structures were determined by spectroscopic methods and quantum chemical calculations. Furthermore, the most abundant compound, orthosiphol K, was structurally modified by modern synthetic techniques to give seven new derivatives (9-15). The anti-rheumatoid arthritis activity of these diterpenoids were evaluated on a TNF-α induced MH7A human rheumatoid fibroblast-like synoviocyte model. Compound 10 showed the most potent activity among these compounds. Based on their inhibitory effects on the release levels of IL-1ß, the preliminary structure-activity relationships were concluded. Furthermore, western blot analysis revealed that 10 could increase the expression of IκBα and decrease the expression of NF-κB p65, and the expression levels of COX-2 and NLRP3 proteins were consequently down-regulated.

Efficacy and safety of the modified Zhiwang decoction combined with methotrexate in early rheumatoid arthritis: study protocol for a randomised controlled trial.

INTRODUCTION: Rheumatoid arthritis (RA) is a progressive inflammatory autoimmune disease characterised by chronic systemic inflammation, which can cause swelling, stiffening and destruction of articular cartilage and bone. Early diagnosis and treatment of RA can improve outcomes and slow the progression of joint damage. Preliminary exploratory research had hinted an expected effect of modified Zhiwang decoction (MZWD) in treating early RA. However, few randomised clinical trials have evaluated the effectiveness of MZWD in early RA. Therefore, a parallel-group randomised controlled trial was designed to evaluate the efficacy and safety of MZWD combined with methotrexate (MTX) on early RA. METHODS AND ANALYSIS: This is a prospective, parallel-group, single-centre randomised controlled clinical study. A total of 150 patients will be randomly assigned to either the treatment (n=75) or control group (n=75). The treatment group will receive MZWD and MTX, and the control group will receive MTX for 12 weeks. The primary outcome of this study is Disease Activity Score-28, and the secondary outcomes are Fatigue Scale-14, Visual Analogue Scale pain scores and traditional Chinese medicine symptom scores. Safety outcomes, including adverse events and results of ECG and laboratory tests, will be monitored. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Clinical Research Ethics Committee of the China-Japan Friendship Hospital (no. 2022-KY-124) on 8 July 2022. The findings will be disseminated in peer-reviewed publications. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT05508815).