Tripterygium Wilfordii HOOK.F. (TwHF)

Toxic, immunosuppressive medicinal plant from China, see also under three-winged fruit. Tripterygium Wilfordii HOOK.F. (TwHF) is the only plant mentioned in the AMWF guidelines for rheumatoid polyarthritis.

Studies confirm its efficacy in autoimmune diseases, including psoriasis, where it is even more effective than methotrexate (Zhang W et al. 2015). The toxicity of the drug is problematic.

In China, too, only a 50 % ethanol extract of the root is approved as "Kunming-Shanhaitang tablets" for lupus erythematosus and rheumatoid arthritis (Wiebrecht A et al. 2021).

More than 70 ingredients, diterpenoids, triterpenoids, sesquiterpenoids, β-sitosterol, dulcitol and glycosides. The most effective bioactive substance is triptolide (C20H24O6). This has strong anti-inflammatory and immunosuppressive properties (Han R et al. 2012).

Modulation of type 3 inflammatory cytokines, incl. IL-22, IL-23 and IL-17, as well as Th17 lymphocytes and γδT cells (T cells with a pronounced T cell receptor on the surface), intervention in the IFN-SOCS1 signaling pathways (a suppressor of cytokine signals inhibits the signal transmission of type I interferon (IFN) via the tyrosine kinase Tyk2 associated with the interferon alpha receptor(IFNAR1)) and IL-36α. In vitro (Ru Y, 2020) Inhibition of keratinocyte proliferation, increase in the concentration of apoptosis factors, also inhibition of human peripheral blood mononuclear cells and the generation of cytotoxic T cells. Cause: Reduction of IL-2 production or IL-2 receptor expression, influence on killer cell-mediated cytotoxicity.

The overall incidence of adverse events is 26.7 %. They mainly concern gastrointestinal symptoms, reproductive disorders, amennorrhea, increase in liver values, skin reactions, haematological changes, leukopenia, proteinuria, palpitations, headaches, increased blood sugar and hair loss.

The three-winged fruit was also used externally for arthritic complaints. In 2023, a double-blind, randomized, placebo-controlled clinical trial was conducted over 4 weeks with a three-winged fruit cream in 70 patients with rheumatoid arthritis (Jiao J et al. 2019). The success rate of a 20% improvement in the American College of Rheumatology criteria (ACR20) at week 4, but also ACR50 and the above-mentioned 28-joint Disease Activity Scores (DAS28) were assessed. 34.3 % (12/35) of the TwHF cream group and 11.4 % (4/35) of the placebo group (P = 0.015) showed a 20 % improvement after 4 weeks. A 50 % improvement was seen in 17.1 % (6/35) in the TwHF cream group versus 2.9 % (1/35) in the placebo group. Comparable improvement in DAS28 and CRP as well as the number of tender and swollen joints.

1. Han R et al. (2012) Triptolide in the treatment of psoriasis and other immune-mediated inflammatory diseases. Br J Clin Pharmacol 74:424-36. doi: 10.1111/j.1365-2125.2012.04221.x. PMID: 22348323; PMCID: PMC3477344.

2. Jiao J et al. (2019) Effect of cream, prepared with Tripterygium wilfordii Hook F and other four medicinals, on joint pain and swelling in patients with rheumatoid arthritis: a double-blinded, randomized, placebo controlled clinical trial. J Tradit Chin Med 39:89-96.

3. Ru Y et al. (2020) Role of keratinocytes and immune cells in the anti-inflammatory effects of Tripterygium wilfordii Hook. f. in a murine model of psoriasis. Phytomedicine. 77:153299. doi: 10.1016/j.phymed.2020.153299. Epub 2020 Aug 13. PMID: 32823074.

4. Wang Y et al. (2023) Tripterygium wilfordii Hook. F. and Its Extracts for Psoriasis: Efficacy and Mechanism. Drug Des Devel Ther. 20:3767-3781. doi: 10.2147/DDDT.S439534. PMID: 38144417; PMCID: PMC10749103.

5. Wiebrecht A et al. (2021) Journal of Phytotherapy 42: 213-214 DOI: 10.1055/a-1406-4868

6. Zhang W et al. (2015) Comparison of Tripterygium wilfordii Hook F with methotrexate in the treatment of active rheumatoid arthritis (TRIFRA): a randomized, controlled clinical trial. Ann Rheum Dis. 74:1078-86. doi: 10.1136/annrheumdis-2013-204807. Epub 2014 Apr 14. PMID: 24733191