Triptolide immunosuppressive activity

Triptolide, isolated from the herb Tripterygium wilfordii Hook F, has anti-inflammatory and immunosuppressive activities, and... 

In the past 20 years hundreds of Chinese traditional and herbal medicines with immunomodulating functions have been screened, and their active components studied. Through these studies, six diterpene lactone epoxide compounds, with antiinflammatory and immunosuppressive actions, were isolated from T. wilfordii. Zheng et al. [183] assayed the half-effective dose (ED50), the therapeutic index (TI) and a certain safety factor (CSF) using croton oil induced ear swelling and hemolysin-antibody formation mouse models and found that triptolide (79), tripdiolide (80), triptonide (81), tripchlorolide (92), and triptolidenol (93) possessed both antiinflammatory and immunosuppressive activities, while triptriolide (94) showed antiinflammatory action only. Fig. (28). The results of the TI and CSF of both activities clearly demonstrated that the antiinflammatory and immunosuppressive compounds in T. wilfordii are pluralistic and the differences in these compounds can be used as a base for the evaluation and selection of them. 

Other activities of triptolide and of T. ivilfordii extracts are discussed in a recent review these include immunosuppressive and anti-inflammatory effects as well as antiproliferative effects. The potential as well as the chemical complexity of triptolide have led to several synthetic approaches to the compound but current supplies are still provided by isolation from T. wilfordii. Some investigations of plant tissue culture production methods have been carried out " but this approach is not yet practical on a large scale, so compound supply could be an issue in the event that PG490-88 or a related compound is approved for clinical use. Triptolide is thus a versatile lead compound and it will be interesting to find out if its diverse activities lead to clinical benefits to cancer patients. 

The above mentioned data suggest that triptolide has a suppressive effect on cellular immune function. The suppressive mechanism may be related to the suppression of Th cells and IL-2 secretion activity and the induction of Ts cells. Triptolide is one of the main immunosuppressive components of T. wilfordii and, although its mechanism of action remains to be further elucidated, represents a novel class of drugs with potential a clinical utility [188]. 

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