Antiproliferative activity of root extract from gentian plant (Gentiana triflora) on cultured and implanted tumor cells - Matsukawa, K; Ogata, M; Hikage, T; Minami, H; Shimotai, Y; Saitoh, Y; Yamashita, T; Ouchi, A; Tsutsumi, R; Fujioka, T; Tsutsumi, K I (Biosci Biotechnol Biochem, 2006)