title: Polysaccharide Extracted from Laminaria japonica Delays Intrinsic Skin Aging in Mice.
abstract: This study aimed to determine the effect of topically applied Laminaria polysaccharide (LP) on skin aging. We applied ointment containing LP (10, 25, and 50 μg/g) or vitamin E (10 μg/g) to the dorsal skin of aging mice for 12 months and young control mice for 4 weeks. Electron microscopy analysis of skin samples revealed that LP increased dermal thickness and skin collagen content. Tissue inhibitor of metalloprotease- (TIMP-) 1 expression was upregulated while that of matrix metalloproteinase- (MMP-) 1 was downregulated in skin tissue of LP-treated as compared to untreated aging mice. Additionally, phosphorylation of c-Jun N-terminal kinase (JNK) and p38 was higher in aging skin than in young skin, while LP treatment suppressed phospho-JNK expression. LP application also enhanced the expression of antioxidative enzymes in skin tissue, causing a decrease in malondialdehyde levels and increases in superoxide dismutase, catalase, and glutathione peroxidase levels relative to those in untreated aging mice. These results indicate that LP inhibits MMP-1 expression by preventing oxidative stress and JNK phosphorylation, thereby delaying skin collagen breakdown during aging.
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China; Center of Translational Medicine, Guangxi Medical University, Nanning 530021, China.
authors.forename: Longyuan
authors.initials: L
authors.lastname: Hu
authors.affiliation: First Clinical Medical College, Guangzhou Medical University, Guangzhou 511436, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Tan
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Yang
authors.affiliation: Eighth Affiliated Hospital, Guangxi Medical University, Guigang 530007, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Tan
authors.affiliation: Center of Translational Medicine, Guangxi Medical University, Nanning 530021, China.
authors.forename: Xiaozhen
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Manhang
authors.initials: M
authors.lastname: You
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Qin
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Liangzhao
authors.initials: L
authors.lastname: Huang
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Manqiu
authors.initials: M
authors.lastname: Mo
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Huifen
authors.initials: H
authors.lastname: Wei
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China; Center of Translational Medicine, Guangxi Medical University, Nanning 530021, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Physiology, Guangxi Medical University, Nanning 530021, China; Center of Translational Medicine, Guangxi Medical University, Nanning 530021, China.
authors.forename: Jiyong
authors.initials: J
authors.lastname: Tan