The present invention provides an inhibitor of NF-.kappa.B, guggulsterone
and its analogs. Guggulsterone suppresses NF-.kappa.B activation induced
by TNF, phorbol ester, okadaic acid, cigarette smoke, H.sub.2O.sub.2 and
IL-1.beta., as well as constitutive NF-.kappa.B activation expressed in
most tumor cells. One mechanism by which guggulsterone inhibits
activation of NF-.kappa.B is through suppression of I.kappa.B.alpha.
phosphorylation and I.kappa.B.alpha. degradation. NF-.kappa.B-dependent
gene transcription is modulated by guggulsterone and its analogs. In
particular, induction by TNF, TNFR1, TRADD, TRAF2, NIK and IKK, is
modulated by guggulsterone and its analogs. In addition, guggulsterone
decreased the expression of genes involved in anti-apoptosis (IAP1, XIAP,
Bfl-1/A1, bcl-2, cFLIP, survivin), proliferation (cyclin D1, c-myc) and
metastasis (MMP-9, COX2 and VEGF).