All herbs, roots, barks, flowers, etc. contain chemicals - these chemicals will travel through the bloodstream and do their jobs - regardless of what food is eaten.
Herbs ARE drugs and work in the same manner. It is the same as when someone takes high blood pressure medication or even Tylenol - there are no diet requirements for the medication to work.
It is always healthier on your body and especially your liver - to eat as naturally as possible. Avoid all the food additive chemicals that you can.