Chronological aging and photoaging affect appearance, causing wrinkles, pigmentation, texture changes, and loss of elasticity in the skin. Phragmites communis is a tall perennial herb used for its high nutritional value and for medicinal purposes, such as relief from fever and vomiting and facilitation of diuresis. In this study, we investigated the effects of ethanol extract of P. communis rhizome (PCE) on skin aging. The total flavonoid and total phenolic content in PCE were 2.92 ± 0.007 ㎍ of quercetin equivalents (QE) and 231.8 ± 0.001 ㎍ of gallic acid equivalents (GAE) per 100 ㎎ of dried extract (n = 3). The half-maximal inhibitory concentration (IC50) values of PCE for 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and hydrogen peroxide scavenging activities were 0.96 and 0.97 ㎎/mL, respectively. PCE showed inhibitory effects on tyrosinase when L-tyrosine (IC50 = 1.25 ㎎/mL) and L-3,4-dihydroxyphenylalanine (IC50 = 0.92 ㎎/mL) were used as substrates. PCE treatment up to 200 ㎍/mL for 24 h did not cause any significant cytotoxicity in B16F10 melanocytes, human dermal fibroblasts (HDFs), and HaCaT keratinocytes. In B16F10 melanocytes, PCE (25 and 50 ㎍ /mL) inhibited melanin production and cellular tyrosinase activity after challenge with α-melanocyte-stimulating hormone (α-MSH; p < 0.05). In HDFs, PCE suppressed the mRNA expression of matrix metalloproteinase-1 (MMP-1) and reduced the activity of elastase (p < 0.05). In addition, ultraviolet B (UVB)-mediated downregulation of hyaluronic acid synthase-2 gene expression in HaCaT keratinocytes was also effectively suppressed by PCE treatment. Overall, our results showed that PCE has potential anti-skin aging activity associated with the suppression of hyperpigmentation, wrinkle formation, and reduction in dryness. PCE is a promising candidate for the development of an anti-skin aging cosmetic ingredient.

Abstract
Introduction
Materials and Methods
    Chemicals
    Preparation of P. communis Trinius root extract
    Determination of total phenolic content and total flavonoidcontent
    Determination of DPPH radical scavenging activity
    Determination of hydrogen peroxide scavenging activity
    Cell culture
    Cell viability
    Measurement of melanin production in B16F10 melanocytes
    Measurement of tyrosinase inhibitory activity
    Measurement of cellular elastase activity
    UVB irradiation
    Quantitative RT-PCR (qRT-PCR) analysis of MMP-1 andHAS-2 mRNA expression
    Statistical analysis
Results
    Total phenolic content and total flavonoid content
    Radical scavenging activity of PCE
    Inhibitory effect of PCE on tyrosinase activity in vitro
    Effect of PCE on the viability of B16F10 melanocytes,HDFs, and HaCaT keratinocytes
    Inhibitory effect of PCE on melanin production in B16F10melanocytes
    Inhibitory effect of PCE on cellular tyrosinase activitystimulated by α-MSH in B16F10 melanocytes
    Suppressive effect of PCE on the mRNA expression ofMMP-1 in HDFs
    Suppressive effect of PCE on elastase activity in HDFs
    Effect of PCE on the mRNA expression of HAS-2
Discussion
References

• Chang Woo Ha(College of Health Sciences, Kangwon National University)
• Sung Hyeok Kim(College of Health Sciences, Kangwon National University)
• Sung Ryul Lee(Department of Convergence Biomedical Science, Cardiovascular and Metabolic Disease Center, College of Medicine, Inje University)
• Sohee Jang(College of Health Sciences, Kangwon National University)
• Seung Namkoong(College of Health Sciences, Kangwon National University)
• Sungsil Hong(College of Health Sciences, Kangwon National University)
• Hyosun Lim(Korea Research Institute Bio Science Co., Ltd.)
• Youn Kyu Kim(Korea Research Institute Bio Science Co., Ltd.)
• Eun-Hwa Sohn(College of Health Sciences, Kangwon National University/Department of Bio-Health Convergence, Kangwon National University) Corresponding author