Although we did not examine behavioral improvements or attempt to quantify brain damage reduction by tryptanthrin in our MCAO model, the study provides evidence tryptanthrin might control the function of microglia through Nrf2/HO-1 and NF-κB signaling, which suggests tryptanthrin could alleviate neuropathology of neuroinflammatory disease such as stroke. Here, HMOX1 is linked to Stroke.