- Aryl hydrocarbon receptor-mediated induction of microsomal drug-metabolizing enzyme activity by indirubin and indigo. Sugihara, K., Kitamura, S., Yamada, T., Okayama, T., Ohta, S., Yamashita, K., Yasuda, M., Fujii-Kuriyama, Y., Saeki, K., Matsui, S., Matsuda, T. Biochem. Biophys. Res. Commun. (2004)