Stimulatory effect of dietary red ginseng on epidermal hydration and ceramide levels in ultraviolet-irradiated hairless mice.

Ultraviolet (UV) irradiation induces skin dryness, largely by disruption of the epidermal barrier. In a search for dietary and plant compounds that would protect against skin dryness, we investigated the dietary effect of red ginseng (the steamed root of Panax ginseng C.A. Meyer) on epidermal levels of hydration and ceramides, the most important lipids for maintaining the epidermal barrier, in UV-irradiated mice. Albino hairless mice were fed either control diets (group UV [UV-irradiated control]) or diets with 0.5% (group H0.5) or 1% (group H1.0) red ginseng extract for 5 weeks in parallel with UV irradiation. A normal control group (group C) was fed a control diet without UV irradiation for 5 weeks. Skin dryness in group UV, as assessed by epidermal levels of hydration and ceramides, was significantly lower than those in group C. With no differences in food intake and weight gains among groups, epidermal levels of hydration and ceramides in group H0.5 were similar to those in group C. In addition, protein expression of serine palmitoyltransferase (SPT), a key enzyme involved in de novo ceramide synthesis, was increased in group H0.5. However, epidermal levels of hydration and ceramides in group H1.0 did not differ from those in group UV, in which ceramidase, an enzyme involved in ceramide degradation, was highly expressed. In conclusion, we demonstrate that dietary supplementation of 0.5% red ginseng protects skin from UV-induced dryness with an accumulation of ceramides due to elevated expression of SPT protein.

Effects of red ginseng extract on UVB irradiation-induced skin aging in hairless mice.

UNLABELLED: Panax ginseng C.A. Meyer, Korean herb medicine, has been widely used in China and Japan for fatigue and enhancement of resistance to many diseases. AIM OF THE STUDY: This study is aimed to assess the effects of Korean red ginseng extract on UVB irradiation induced skin aging in hairless mice. MATERIALS AND METHODS: Red ginseng extracts prepared with ethanol were used in this study. To standardize Korean red ginseng, it was analyzed by HPLC. And inhibitory effects of red ginseng extract on UVB irradiation-induced skin aging in hairless mice were determined by the measurement of wrinkle, expression of type I procollagen and MMP-1 and immunohistology. RESULTS: Based on the HPLC quantitative analysis, ginsenoside Rb1 content in Korean red ginseng was 43.5mg/g of extract. In the result of body weight gain and food efficiency rate, body weights of all groups were increased during experimental periods. In the wrinkle measurement and image analysis of skin replicas, the results showed that the dietary supply containing red ginseng extract significantly inhibited wrinkle formation caused by chronic UVB irradiation. In the changes of expression of procollagen type I and MMP-1 in the skin of UV irradiated hairless mice fed dietary supplement containing 2.5% red ginseng extract, level of mRNA of procollagen type I was decreased. But protein level of that was increased. And in terms of MMP-1, either mRNA or protein levels of MMP-1 were significantly decreased. These results showed anti-wrinkle effect of Korean red ginseng involved the inhibition of collagen degradation rather than increased collagen synthesis. CONCLUSION: It is shown that Korean red ginseng may be functional food candidate for skin photoaging.