J Rheumatol. 2001 Oct; 28(10): 2160-7.

A phase I study of ethyl acetate extract of the chinese antirheumatic herb Tripterygium wilfordii hook F in rheumatoid arthritis.

Tao X, Cush JJ, Garret M, Lipsky PE.

Harold C. Simmons Arthritis Center, The University of Texas Southwestern Medical Center at Dallas, USA.

OBJECTIVE: To explore the efficacy and safety of ethyl acetate (EA) extracts of the Chinese herbal remedy Tripterygium wilfordii Hook F (TWHF) for treatment of patients with a variety of inflammatory and autoimmune diseases including rheumatoid arthritis (RA). METHODS: The roots of TWHF were extracted sequentially by ethyl alcohol and ethyl acetate and the content of the extract documented. An open label, dose escalation Phase I study was performed in 1993 in 13 patients with established RA. Clinical manifestations and laboratory findings were examined before and every 4 weeks after starting treatment with the EA extract. RESULTS: Three patients withdrew from the trial during the first 16 weeks of the dose escalation. These patients received a maximum dosage of 180 mg/day. There were no adverse effects or disease improvement observed in these patients. Nine of the remaining 10 patients tolerated the EA extract up to a dosage of 570 mg/day. There were no withdrawals related to adverse events in the trial except for one patient who developed diastolic hypertension at a dose of 180 mg/day of EA extract. Six of 10 patients treated with 180 mg/day of EA extract showed disease improvement. Eight of the 9 patients who received EA extract at doses > 360 mg/day experienced improvement in both clinical manifestations and laboratory findings. One patient met American College of Rheumatology criteria for remission. CONCLUSION: The EA extract of TWHF at dosages up to 570 mg/day appeared to be safe, and doses > 360 mg/day were associated with clinical benefit in patients with RA.