실크 단백질 Sericin 및 Fibroin의 식이 공급이 아토피 피부염 동물 모델 NC/Nga Mice의 혈장과 표피의 유리 아미노산 함량에 미치는 영향

• Published in: Hanʼguk yongyang hakhoe chi Vol. 39; no. 6; pp. 520 - 528
• Main Authors: 김현애(Kim Hyunae), 박경호(Park Kyung-Ho), 여주홍(Yeo Joo-Hong), 이광길(Lee Kwang-Gill), 정도현(Jeong Do-Hyeon), 김성한(Kim Sung-Han), 조윤희(Cho Yunhi)
• Format: Journal Article
• Language: Korean
• Published: 한국영양학회 2006
• Subjects: NC/Nga mice; sericin; fibroin; Natural Moisturizing Factor; amino acid
• ISSN: 0367-6463; 2005-7121

Free amino acids in epidermis function as a major component of Natural Moisturizing Factor (NMF), which maintains the optimal level of water in skin even at the low humidity. In fact, the depletion of free amino acids is reported in the epidermis of atopic dermatitis, the skin condition involving dryness. As an effort searching the dietary source for improving the level of water and free amino acid in epidermis, the dietary effects of silk protein, sericin (S) and fibroin (F) on trans epidermal water loss (TEWL), and plasma and epidermal levels of free amino acids were compared in this study. Thirty of male NC/Nga mice, an animal model of atopic dermatitis, were divided into three groups: group CA as an atopic control with control diet, group S: 1% sericin diet and group F: 1% fibroin diet. Ten of male BALB/c mice were served as group C (control group) with control diet. All mice were fed on diet and water ad libitum for 10weeks. Dry skin condition was established in group CA as TEWL was increased (148.7% of group C). In parallel, epidermal level of glutamate, one of major amino acids functioning as NMF, was dramatically decreased and epidermal levels of methionine and alanine were inversely elevated. Dietary supplementation of sericin (group S) reduced TEWL at the similar level with group C and increased epidermal levels of glutamate as well as serine and glycine, the other major amino acids as NMF. Despite a marked decrease of methionine and alanine, the reduction of TEWL and epidermal levels of glutamate, serine and glycine of group F were less than of group S. Furthermore, in contrast to similar levels of other free amino acids in plasma and epidermis of group S and group C, plasma and epidermal levels of other free amino acids, specifically phenylalanine, isoleucine, cysteine and tyrosine in epidermis of group F, were significantly higher than of group C. Together, our data demonstrate that dietary supplementation of sericin is more effective at improving dry skin condition that paralleled with the normalization of free amino acids in plasma and epidermis of NC/Nga mice.