Herbal Photoprotective Formulations and their Evaluation

Photochemoprevention has become an important armamentarium in the fight against ultraviolet radiation induced damage to the skin. UV irradiation to skin results in erythema, edema, sunburn cells, hyperplasia, immunosuppression, photoaging and photocarcinogenesis. Various synthetic agents have been used as photoprotectives but they have limited use because of their potential toxicity in humans and their ability to interfere only in selected pathways of multistage process of carcinogenesis. Several botanical compounds have been shown to be antimutagenic, anticarcinogenic and nontoxic and have ability to exert striking inhibitory effects on a plethora of cellular events at various stages of carcinogenesis. Since multiple pathways are involved in photocarcinogenesis so mixture of several botanical antioxidants working through various mechanisms, in conjunction with the use of sunscreens could also be an effective approach for reducing photoaging and skin cancer in humans. The performance of sunscreen substances could be improved by modification of their chemical, physical and technological properties or by the use of novel carriers like liposomes, nanoparticles, phytosomes, transferosomes, nanospheres etc. The application of novel approaches can also improve its efficacy regarding continuous action of herbs on the human body. This review will focus on list of herbs, formulations and evaluation parameters of photoprotective herbs.