4 ', 6'-ДИМЕТОКСИ-2'-ГИДРОКСИХАЛКОН

Flavokawain B is a natural chalcone first isolated from extracts of kava roots. It induces apoptosis in androgen receptor-negative, hormone-refractory prostate cancer cell lines (IC₅₀s = 32, 48, 6.2, and 3.9 μM for LAPC4, LNCaP, PC-3, and DU145 cells, respectively, treated for 48 hours), with increased expression of the proapoptotic protein Bim. Flavokawain B increases Bim expression and inhibits growth of DU145 xenografts in mice. It also increases Bim expression, promotes apoptosis, and induces cell cycle arrest in uterine leiomyosarcoma cells. However, flavokawain B is hepatotoxic, triggering oxidative stress, inhibiting NF-κB signaling, and activating MAPK pathways, culminating in HepG2 and L-02 cell death (LD₅₀s = 15 and 32 μM, respectively).

Flavokavain B is a secondary metabolite of the kava plant (Piper methysticum Forst. f., Piperaceae, which has anticancer properties and demonstrated oral efficacy in murine cancer models. ?Futhermore, it also has suspected roles in rare cases of kava-induced hepatotoxicity. In addition, it is a potential candidate for the development of novel antifungal phytotherapic products.