SIRT3 and brain injury: Our observation that honokiol protection against oxidant-induced AEC mtDNA damage occurs in a SIRT3-dependent manner concurs with prior studies showing that honokiol’s protective effects are dependent upon SIRT3 in ameliorating murine bleomycin-induced pulmonary fibrosis [37], doxorubicin-induced cardiomyopathy [49], diabetes-induced myocardial dysfunction [51], and radiation-induced brain injury [52].