Celastrol is a pentacyclic triterpenoid isolated from the root extracts of Tripterygium wilfordii, a perrennial creeping plant indigenous to large area in Southern China. Celastrol possess antioxidant and anti-inflammatory and anticancer action. In the mouse model of rheumatoid arthritis it reduced inflammatory swelling, suppressed humoral and skin response and reduced pathological progression of joint. Celastrol demonstrated efficacy in transgenic mouse model of amyotrophic lateral sclerosis. Anticancer activity of celastrol was shown in xenograft models of prostate cancer. Celastrol suppresses food intake, blocks reduction of energy expenditure, and leads to up to 45% weight loss in hyperleptinemic diet-induced obese (DIO) mice by increasing leptin sensitivity. Celastrol acts by interfering with the activity of Hsp90, IKK-beta and proteasome S26 subunit.