- Involvement of reactive oxygen species, but not mitochondrial permeability transition in the apoptotic induction of human SK-Hep-1 hepatoma cells by shikonin. Chen, C.H., Chern, C.L., Lin, C.C., Lu, F.J., Shih, M.K., Hsieh, P.Y., Liu, T.Z. Planta Med. (2003)