The Effect Of Laminarin Polysaccharide On Skin Collagen In Intrinsic Aging Mice

Objective: To study the Anti-aging effect of Laminarin polysaccharide(LP) on skin collagen in the intrinsic aging mice.Method:To set up the aging animal model, eight weeks-old mice were prepared with dorsal hair shaved and randomly divided into normal control group, aging model group, Laminaria polysaccharide low does group(LP-L), LP middle dose group(LP- M), LP high dose group(LP- H) and Vitamin E positive control group(Vit.E). They were respectively coated with drugs once each morning and afternoon. 12 months later,exposed dorsal skins of the mice were collected, except for the mice in control group (Exposed dorsal skins of the mice were collected after 1 monthe later).1. The skins were respectively detected thickness of dermis through HE stain and hydroxyproline (Hyp) by chemical colorimetry;2. The skins were respectively detected the mRNA expressions of MMP-1 and TIMP-1 by real-time fluorescent quantization PCR;3. The skins were respectively detected the protein expressions of MMP-1 and TIMP-1 by Western Blot;4. The skins were respectively detected the contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) by chemical colorimetry;5. The skins were respectively detected the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxide (GSH-Px) by chemical colorimetry.Results:1. Compared to control group, thickness of dermis and hydroxypro-line (Hyp) were markedly decreased (P<0.05) in the model group. Comp-ared to model group, LP-M, LP-H, VitE could signifycantly increase the thickness of dermis(P<0.05) and skin Hyp content(P<0.05).2. Compared to control group, the mRNA expression of MMP-1 was markedly increased (P<0.01) while the mRNA expression of TIMP-lwas markedly decreased (P<0.01) in the model group .Compared to model group, LP-M, LP-H, VitE could signifycantly increase the mRNA expression of TIMP-1(P<0.05), but decrease the mRNA expression of MMP-1(P<0.05).3. Compared to control group, the protein expression of MMP-1 was markedly increased (P<0.01) while the protein expression of TIMP-lwas markedly decreased (P<0.01) in the model group. Compared to model group, LP-M, LP-H, VitE could signifycantly increase the protein expression of TIMP-1(P< 0.05),but decrease the protein expression of MMP-1(P<0.05).4. Compared to control group, the skin contents of MDA, H2O2 were markedly increased in the model group (P<0.05). Compared to model group, LP-M, LP-H and VitE could signifycantly decrease the skin contents of MDA, H2O2 (P<0.05).5. Compared to control group, the activities of SOD, CAT, GSH-Px were markedly decreased in the model group(P<0.05). Compared to model group, LP-M, LP-H and VitE could signifycantly increase the of SOD, CAT,GSH-Px (P<0.05).Conclusion: LP can prolong the ageing process through regulating the content of collagen. The mechanism of LP was related with its adjusting the activity of matrix metalloproteinase by decreasing the oxygen radical.