Rhapontigenin is an apoptosis-inducing agent, and also a potent and selective cytochrome P450 1A1 inhibitor with IC50 value of 0.4 μM [1][2].

Human cytochrome P450 (P450) 1A1 is an aryl hydrocarbon hydroxylase which involved in the metabolic activation of procarcinogens of the polycyclic aromatic hydrocarbons. P450 1A1 is mainly expressed in human lung, placenta, and lymphocytes. Selective inhibitors of P450 1A1 may be good chemopreventive agent candidates for cancer [2].

Rhapontigenin is an apoptosis-inducing agent and a cytochrome P450 1A1 inhibitor. Rhapontigenin inhibited recombinant human cytochrome P450 (P450) 1A1 with IC50 value of 0.4 μM. Rhapontigenin showed 400-fold and 23-fold selectivity for P450 1A1 over P450 1A2 and P450 1B1, respectively. Rhapontigenin showed competitive inhibition of P450 1A1 with Ki value of 0.21 μM [1]. Rhapontigenin is a natural analog of resveratrol, a potential cancer chemopreventive agent. In the HL60 cell line, Rhapontigenin inhibited cell proliferation with IC50 value of 48 μM [2]. In Hep G2 hepatoma cells, Rhapontigenin exhibited concentration-dependent anti-cancer activity with IC50 value of 115 μg/mL [3].

References:
[1].  Chun YJ, Ryu SY, Jeong TC, et al. Mechanism-based inhibition of human cytochrome P450 1A1 by rhapontigenin. Drug Metab Dispos. 2001 Apr;29(4 Pt 1):389-93.
[2].  Roberti M1, Pizzirani D, Simoni D, et al. Synthesis and biological evaluation of resveratrol and analogues as apoptosis-inducing agents. J Med Chem. 2003 Jul 31;46(16):3546-54.
[3].  Roupe KA1, Helms GL, Halls SC, et al. Preparative enzymatic synthesis and HPLC analysis of rhapontigenin: applications to metabolism, pharmacokinetics and anti-cancer studies. J Pharm Pharm Sci. 2005 Aug 22;8(3):374-86.