ABSTRACT
Phytocosmetics with efficacy for skin care are globally becoming increasingly popular items for women to keep their skin healthy and to maintain and improve its beauty. Skin care efficacy is roughly classified into three characteristics – moisturizing, reducing pigmented spots and reducing wrinkles. Knowledge about the causative mechanisms and factors involved in the impairment of the skin in the view of those three characteristics is being discovered by active dermatological studies. The discovery of such knowledge and factors requires the establishment of new methods to assess substances and factors that might achieve effective skin care. Thus, to understand the concepts of each type of assessment, understanding the causative mechanisms and factors involved is essential. Basically, most skin problems are triggered by excess reactive oxygen species (ROS), induced with age or by external stimuli, and therefore the regulation of ROS levels is an effective way to achieve skin care efficacies. Here, we first introduce current knowledge of the causative mechanisms and factors involved in skin problems focusing on the involvement of ROS, and then we introduce the corresponding methods to assess each problem. The authors hope that this will be of help in designing appropriate assessment methods.
