How to auto unpublish a node after edit and later published by admin?
Here's how you can do this:


Create a rule on node update event.
Add Condition where user role is not "Administrator/Moderator". (This will make sure that the content doesn't get unpublish when admin is updating it.)
If required, Add condition where content is of type "Article".
Add Action "Unpublish content" under node section and save.
Add another action "Send Mail" under System. Add required details to send email and save.


Above steps will unpublish content and notify site admin using email. After which site admin can navigate to "Admin => Content", review the content and approve. If you need to provide a custom/different UI, you can create a list using views and VBO module and allow site admin to Approve Content.