To do Alt + H + 8 on Mac in PowerPoint, download and install Accelerator Keys, then press Option, followed by H, then 8.
Command: Change Case Menu
This is how to do Alt + H + 8 on Mac in PowerPoint with Accelerator Keys, the native ribbon and alt key shortcut solution for Mac users who get more done with PowerPoint.
Alt + H + 8 opens the Change Case menu, which provides options to change the capitalization of selected text. Options include Sentence case, lowercase, UPPERCASE, Capitalize Each Word, and tOGGLE cASE.