Atopic dermatitis is an well-known skin disease showing inflammatory, chronically relapsing, noncontagious and pruritic symptoms. The aims of this study were to investigate the effects of Liriope platyphylla (LP) on atopic dermatitis of NC/Nga mice. To achieve this, NC/Nga mice were treated with four different conditions including vehicle, phthalic anhydride (PA), PA+5% LP and PA+10% LP, and the changes of immune-related factors were detected after 2 weeks. The pathological phenotypes of atopic dermatitis such as erythema, ear thickness, edema, scab and discharge were significantly decreased in PA+10% LP cotreated groups compare to PA treated group. Also, the weight of lymph node and thymus in immune organs were gradually decreased in LP treated groups, while the weight of spleen was slightly increased in same group. Furthermore, toluidine blue staining analysis, a method used to specifically identify the mast cell, showed that the decrease of master cell infiltration into the dermis were statistically observed in PA+5% LP and PA+10% LP5% cotreated groups. Especially, the decrease of IgE concentration was detected only PA+10% LP cotreated group, although this level was maintained in PA+5% LP cotreated group. Therefore, these results suggested that the water extracts of LP may contribute the relieve of atopic dermatitis symptoms and be considered as an excellent candidate for a atopic dermatitis-therapeutic drug.

Abstract. The insulin signaling pathway, involving protein kinase B (PKB) and mitogen-activated protein kinase (MAPK), mediates the biological response to insulin and several growth factors and cytokines. To investigate the correlation between glucose transporter (Glut) biosynthesis and the insulin signaling pathway activated by novel compounds of Liriope platyphylla (LP9M80-H), alterations in Glut and key protein expression in the insulin signaling pathway were analyzed in the liver and brain of ICR mice treated with LP9M80-H. An in vitro assay showed that the highest level of insulin concentration was observed in the LP9M80-H-treated group, followed by the LP-H, LP-M, LP-E, and LP9M80-C-treated groups. Therefore, LP9M80-H was selected for use in studying the detailed mechanism of the insulin signaling pathway in animal systems. In an in vivo experiment, LP9M80-H induced a significant increase in glucose levels and a decrease of insulin concentration in the blood of mice, while their body weight remained constant over 5 days. The expression level of Glut-3 was down-regulated in the liver, or maintained at the same level in the brain of LP9MH80-H-treated mice. These changes corresponded to the phosphorylation of the p38 protein rather than to ERK and JNK in the MAPK signaling pathway. In addition, the expression level of Glut-1 increased significantly after LP9MH80-H treatment of both insulin target tissues in mice. Western blot analysis showed that Akt in the PI3-K pathway mainly participated in Glut-1 biosynthesis. Thus, these results suggest the possibility that the LP9M80-H-induced regulation of Glut-1 and Glut-3 biosynthesis may be mediated by the Akt and p38 MAPK signaling of the insulin signaling pathway in the liver and brain of mice.

Liriope platyphylla has been used in oriental medicine as an effective medical plant to improve symptoms of cough, sputum production, neurodegenerative disorders, obesity and diabetes for long time. In order to investigate the effects of novel extracts on nerve growth factors (NGF)-stimulated neuritic outgrowth, the alteration of NGF expression and NGF receptor signaling pathway were detected in neuroblastoma cells and C57BL/6 mice. Of a total of 13 novel extracts, 4 extracts (LP-E, LP-M, LP-M50, LP2E17PJ) showed high viability on MTT assay. Also, all of these extracts induced NGF secretion and NGF mRNA expression in neuroblastoma cells. However, the NGF-induced neuritic outgrowth from PC12 cells was only stimulated by LP-E, LP-M and LP-M50. Furthermore, we selected LP-M as a best candidate, based on method and amounts of extraction, in order to verify its effect in mice. C57BL/6 mice were treated with 50 mg/kg of LP-M for 2 weeks and the effects on NGF regulation were analyzed with various methods. The expression of NGF mRNA was significantly increased in LP-M treated mice compared to vehicle treated mice. Also, the signaling pathway of p75 NTR was inhibited in the cortex by LP-M treatment, with no change in the hippocampus of brain. However, the signaling pathway of TrkA was dramatically activated in only hippocampus via LP-M treatment. Therefore, these results suggest that the novel four extracts of L. platyphylla may contribute to the regulation of NGF expression and secretion in neuronal cells. LP-M was especially considered to be an excellent candidate for a neurodegenerative disease-therapeutic drug.

Ultraviolet (UV) irradiation is an environmental factor that causes skin aging, and is also a major factor leading to cumulative alterations of skin structure, function and appearance. To investigate the effects of Selenium (Sel) on UV-induced skin aging, hairless mice were treated for 4 weeks with UV irradiation and topical application of Sel. Then, the effects of Sel were measured in the skin of these mice via histological analysis and Western blotting. According to the results of wrinkle formation analysis, the topical application of Sel induced a reduction in wrinkling formation in the damaged skin of the UV-irradiated mice. Additionally, our histological analysis demonstrated that the skin thickness in the Sel-treated group was less than in the UV-irradiated group. Furthermore, in an effort to investigate the mechanisms underlying the effects of Sel, the expression levels of matrix-metalloproteinase (MMP) and MAPK protein were assessed in both groups. The application of Sel induced a reduction in MMP-1 expression levels to the levels observed in the non-irradiated group. However, the expression level of MMP-9 was increased slightly in the Sel application group as compared with the vehicle application group. Additionally, the levels of ERK phosphorylation were increased by the application of Sel, but the levels of JNK and p38 were not altered by Sel treatment. These results suggest the possibility that Sel should be considered as a skin aging-protective and therapeutic drug candidate, which functions via the regulation of MMP expression levels.