Papaya contains a natural enzyme known as papain that has antibacterial and wound-healing abilities. The enzyme also aids in removing dead, damaged skin. To use papaya as a skin toner, mash a few pieces of ripe papaya and apply it as a facial mask. Keep it on for about 15 minutes and then wash it off with lukewarm water. Regular application of papaya juice helps reduce freckles or brown spots due to sun exposure. For extra skin lightening effect, add a slice of lemon to the papaya juice.