## 1 Introduction  
In recent years, there has been increased consumer interest and desire for improved skin health. Accordingly, considerable research studies into the role of food and cosmetics as natural materials that delay natural endogenous skin aging and exogenous skin aging caused by environmental factors such as ultraviolet (UV) rays and air, gave been undertaken [1]. One of the factors involved in skin aging include photoaging due to the repeated exposure to UV rays, which results in decreased moisturization of the skin, decreased elasticity, wrinkle formation, and pigmentation (e.g., erythema) [2].  
Skin tissue is composed of several layers (i.e., epidermis, dermis and subcutaneous fat), with keratinocytes and melanocytes being distribute within the epidermis. The dermis is composed of fibrous and matrix components, 90% of which is collagen present as a fibrous component [3]. In order to maintain health skin, its sufficient moisturization is vital. The skin epidermis, which acts as a physical barrier by preventing the loss of moisture in the body, upon damaged by UV rays is unable to prevent the loss of moisture, causing the skin to become dry, wrinkled, and rough [4].  
The level of moisturization in the skin is determined both by hyaluronic acid in the stratum corneum, and the activity of hyaluron synthase (HAS) which maintains the concentration of hyaluronic acid in the skin [5]. In addition, the action of reactive oxygen species (ROS), caused by continuous UV exposure, not only causes inflammatory reactions,but also promotes the activity of a matrix metalloproteinase (MMP), known as collagenase, which inhibits collagen synthesis in the dermis and promotes wrinkle formation [6; 7]. In response to these UV exposures, the body activates a defense mechanism by increasing tyrosinase activity which leads to melanin production. Melanin plays a crucial role in skin protection by removing ROS [8]. Conversely, excessive melanin production is known to cause melanoma, blemishes, spots, and freckles [9]. Therefore, the development of functional health foods and cosmetics that help in the suppression of skin aging and pigmentation due to UV rays, is mUch needed.  
Hairless mice are commonly used in skin studies. In this work, we used hairless HRM-2 mice that can synthesize melanin pigments, and are also routinely used in melanin synthesis, skin sensitivity, irritation, long-term subcutaneous absorption, and collagen synthesis experiments [10; 11].  
_Zingiber mioga_ (ZM) belongs to the family of ginger and is distributed across East Asia (i.e., Korea, China, and Japan). Recently, it has been reported that ginger extract contains phenolic acids such as pyrogallol p-hydroxy bezoic acid, _p_-coumaric acid, and ferulic acid [12]. Among these, p-coumaric acid is present in free or combined form in plants and mUshrooms such as fruits, vegetables, and grains [13]. In the ginger family, it was reported that the Zingiber officinal species contained coumaric acid [14]. However, few studies on the content or related activity of _p_-coumaric acid in ZM have been performed.  
Therefore, in this study, we evaluated the efficacy of ZM for skin moisturization and depigmentation, and wrinkle improvement in vivo, and assessed the feasibility of its utilization in the development of functional foods and cosmetics for skin health.