Papaya: Papain, better known as papaya proteinase, is an enzyme found in this fruit that helps in skin exfoliation. The process of regeneration of new cells occurs when you go for a papaya treatment. Procedure: Take a ripe papaya and juice it. Apply the mixture on the pigmented area and leave it for 10 minutes. Once you find the mask dry, wash the skin. Repeat this process for a month to achieve positive results.