## 4 Discussion  
Due to climate change and the destruction of the ozone layer, the amount of UV radiation on the earth's surface is progressively increasing; this intensified UV radiation has raised concerns about skin health, globally [17]. UV rays reduce skin moisture, cause wrinkles, pigmentation, and the loss of skin fiber [18]. Long-term exposure to UV light can cause skin cancers such as melanoma, and the use of some drugs to treat skin cancers such as advanced melanoma can cause a variety of side effects [19]. Therefore, there is a growing interest in the development of functional health foods and cosmetics that can help prevent UV ray induced skin damage [1]. For centuries, ginger (_Zingiber officinal_ Roscoe, _Zingiberacae_) has been a crucial ingredient in East Asian markets, found in Ayurvedic and Tibb-Unani herbal medicines for the treatment of asthma, stroke, rheumatism, catarrh, nervous diseases, constipation, gingivitis,  
Figure 6: Inhibitory effects of FSH-ZM on the expressions of mRNA and proteins related to melanogenesis in skin from the back of UVB-irradiated HRM-2 hairless mice. (**A**) The expression of CREB at mRNA and protein level. (**B**) The expression of MITF at mRNA and protein level. (**C**) The expression of tyrosinase mRNA. (**D**) The expression of TRP1 mRNA. NC, normal control; C, UVB-irradiated control; PC1, positive control 1, L-ascorbic acid 200 mg/kg b.w. ; PC2, positive control 2, Arbutin 200 mg/kg b.w. ; Z100, FSH-ZM 100 mg/kg b.w. ; Z200, FSH-ZM 200 mg/kg b.w. Values are presented as mean \(\pm\) standard deviation (n = 6), and different superscript letters indicate significance at \(p<0.05\). and diabetes [20; 21; 22]. _Zingiber mioga_ (ZM), a member of the ginger family, is a perennial plant and is grown in small quantities in Jeju and the southern coast of Korea [23]. Its bud has a peculiar smell and has been used as an ingredient in spices, herbs and pickles for a long time [24]. In addition, ZM's young buds contain zingerene, zingerone, shogaol, \(\beta\)-phellanderene, aframodial, and galanal A/B, shown to be effective in the treatment of leucorrega, menstrual irregularity, odynolysis, eye inflammation, sputum, and heart disease [25; 26]. Moreover, several flavonoids (e.g., rutin, pentahydroflavone, and galangin), anthocyanin compounds (e.g., delphinidine glucoside and delphinidin), [8]-gingerol, and oleamide have been known to be present in ZM [27]. Rutin, a flavonoid present in ZM, has been shown to be effective in preserving phospholipid membranes in skin fibroblasts destroyed after UV irradiation [28]. As a result of measuring the content of \(p\)-coumaric acid, which was selected as a candidate among the active substances of ZM, 0.025 mg/g of \(p\)-coumaric acid was detected in the ZM extract, although not mUch. \(p\)-coumaric acid has been reported to have antimicrobial, antiviral, and anti-cancer activity, and is also used as a hypopigmenting agent [29; 30; 31; 32]. Vitamin C has been used in a wide variety of skin studies. Vitamin C is known to enhance collagen formation [33], remove oxidants [34], inhibit melanogenesis [35], interact with cell signaling pathways [36], inhibit winkles [37], inhibit skin surface roughness [38], and delay skin aging [39]. Also, arbutin has been studied for skin depigmentation [40]. Although there are many different studies of ZM, no animal studies have yet been conducted in skin experiments. In this study, we investigated whether ZM extracts play a role in skin moisturizing, wrinkle suppression, and skin depigmentation in vivo. Z increased the HAS2 mRNA expression, which maintains the concentration of hyaluronic acid, and elastin and fibrillin-1 mRNA expression, which maintain the skin barrier and elasticity, compared with the UVB-irradiated control group. UV irradiation of the skin has been reported to cause inflammation and inhibit hyaluronic acid synthesis [41]. In another recent skin study, we found that lamb placenta increased mRNA expression of HAS2, elastin, and fibrillin-1 in UVB-irradiated animal models [42].