Sikokianin C

Sikokianin C is a natural biflavonoid compound isolated from the medicinal herb Stellera chamaejasme. It functions as a selective, competitive inhibitor of cystathionine β-synthase (CBS), an enzyme involved in the transsulfuration pathway and linked to cancer cell proliferation and migration, particularly in colon cancer. Sikokianin C significantly inhibits the proliferation and induces apoptosis of human colon cancer cells (e.g., HT29) in vitro, and reduces tumor growth in mouse xenograft models. Its mechanism involves binding to the substrate channel of CBS, with five key residues identified for this interaction. Unlike the commonly used CBS inhibitor AOAA, sikokianin C does not inhibit cystathionine γ-lyase (CSE), making it a more selective tool for studying CBS-related pathways. It also demonstrates antimalarial activity against chloroquine-resistant Plasmodium falciparum[1][2][7].