Autophagy in skin: basis for developing proactive cosmetic ingredients
Development of healthy cosmetic ingredients requires a proper definition of “healthy” and biological activity of the cosmetic ingredients can be one of the criteria. Compared with the “biologically inert ingredients without any harmful effects on skin”, proactive ingredients can actively improve skin health. During the last decade, autophagy, originally identified as a cellular recycling or salvage system of cytoplasmic materials via the lysosome, have emerged as an “innate cellular protection” system for healthy and beautiful skin. From the intracellular anti-oxidant system to cellular senescence, diverse important roles of autophagy have been identified in skin. Considering the fundamental roles of autophagy in skin homeostasis, autophagy stimulation can be one of the most fundamental ways to improve skin health and autophagy activator is a good example of proactive healthy ingredient. In this article, brief history of autophagy research in skin and its application for healthy ingredient development will be discussed.
HEALTHY COSMETICS AND SKIN HOMEOSTASIS
Recently, “sustainable, green and healthy cosmetics” become one of the most popular keywords in cosmetic industry. While the healthy cosmetics generally encompasses healthy manufacturing process, healthy products for environments and animals, “cosmetics that help to make healthy skin” can be the basic concept. In this perspective, healthy cosmetics can be described as either being harmless (or non-active) to skin or having significant biological activities on skin. In classical perspective, cosmetic ingredients with significant biological activities can be also described as “cosmeceuticals” (1). Hinted from the recent trends in health care field shifting from reactive to proactive care, bio-active ingredients might be similarly classified into either reactive or proactive ones; while the former is explained as alleviating or attenuating unhealthy skin conditions, including skin dryness, wrinkles, or pigmentation, the latter is defined as reinforcing and fortifying sk ... ...