Celastrol is a compound found in the Thunder God Vine, Tripterygium wilfordii. It is a pentacylic triterpenoid with a structure that resembles steroid hormones. The Thunder God Vine has a long traditional use as an anti-inflammatory.
In a 2014 study, celastrol was shown to inhibit inflammatory and neuropathic pain. This effect was not seen when celastrol was administered along with SR144528, a compound that selectively blocks the CB2 receptors.