Inhibition of P-glycoprotein by orange juice components, polymethoxyflavones in adriamycin-resistant human myelogenous leukemia (K562/ADM) cells - Ikegawa,T.; Ushigome,F.; Koyabu,N.; Morimoto,S.; Shoyama,Y.; Naito,M.; Tsuruo,T.; Ohtani,H.; Sawada,Y. (Cancer Letters, 2000)