Skin Whitening and Green Papaya

I'm a high school junior from the Philippines. I am planning to use green papaya soap in a school project for chemistry. My group plans to study the effectivity of the green papaya (which is a common ingredient in many local skin whitening soaps) especially in regards to papain. Any information on this topic would be of great help to me and I would greatly appreciate it.

I do not have any information on the effect of papain on skin whitening.
As natural practitioners, herbalists work to keep the body in balance naturally. We believe that all natural colours of skin are perfect the way they are, and actively discourage using skin whitening products, many of which contain chemicals that cause serious health damage.