hellebrigenin

Hellebrigenin is a **cardiac steroid (bufadienolide)** isolated from various natural sources, notably toad skin (e.g., Bufo gargarizans, Bufo bufo) and plants such as Helleborus, Kalanchoe, and Urginea[4][3]. Structurally, it is a steroid lactone and is functionally related to bufanolides[4][6]. Hellebrigenin exhibits multiple bioactivities, including induction of apoptosis and autophagy, and potent antineoplastic activity in vitro against several cancer cell lines[1][3][4]. Its mechanism of action involves the inhibition of Na+/K+-ATPase, resulting in DNA damage, cell cycle arrest (mainly G2/M phase or G0/G1 phase depending on cell type), mitochondrial membrane potential disruption, and activation of both intrinsic (mitochondrial) and extrinsic (death receptor-mediated) apoptotic pathways through upregulation of Fas, DR5, Bax and Bak, and downregulation of Bcl-2 and Bcl-xL[1][3][6]. Upstream, hellebrigenin inhibits MAPK pathway signaling (ERK, p38, JNK phosphorylation) and suppresses XIAP, promoting caspase-dependent cell death[1].

Other names

hellebrigeninbufotalidin5-beta-BUFA-20,22-DIENOLIDE3-beta,5,14-TRIHYDROXY-19-OXO