ACE and Hypertension: Overactivation of brain angiotensin-converting enzyme (ACE)–angiotensin II (Ang II)–angiotensin II type 1 receptor (AT1R) axis has been found to play a important role in the development and maintenance of hypertension and then elevated oxidative stress in brain and increased the activity of sympathetic nervous system (Veerasingham and Raizada, 2003).