Oxidative stress stimulated by angiotensin II (Ang II) plays an important role in the progression of inflammation and cardiovascular disease. In this work, polythiophene modified with dihydropyridine groups (PTDHP) realized the control of oxidative stress induced by Angiotensin II stimulation in living cells, by inhibiting the activity of NADPH oxidase via DHP groups. Upon light irradiation, the PcDHP could sensitize surrounding oxygen molecules to generate reactive oxygen species (ROS). The generated ROS oxidized the pendant DHP of polythiophene into pyridine group, which inactivated the control ability of DHP to oxidative stress in living cells. Thus, PTDHP can not only control the intracellular oxidative stress effectively and suppress ROS to some degree in dark, but also regulate its anti-oxidative effect under light irradiation. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.