Alzheimer's disease (AD) occurs when neurons in the memory and cognition regions of the brain are accompanied by an accumulation of the long amyloid beta-proteins of the 39 to 43 amino acids derived from the amyloid precursor protein (APP) by cleavage with beta- and gamma-secretase. An increased production of Abeta-42 by mutation of PS2 genes promotes caspase expression and is associated with the Cox-2 found in the brain of AD patients. To address this question in vivo, we expressed the human mutant PS2 (hPS2m) (N141I) as well as wild PS2 (hPS2w) as a control in transgenic (Tg) mice under control of the neuron-specific enolase (NSE) promoter. Water maze tests were used to demonstrate the behavioral defect; dot blot, Western blot, and immunohistochemical analyses were performed on the brain with the hPS2, Abeta-42, caspase-3, and Cox-2 antibody. We concluded that 1) Tg mice showed a behavioral dysfunction in the water maze test, 2) levels of hPS2, Abeta-42, caspase-3, and Cox-2 expression were modulated in the brains of both Tg mice, 3) dense staining with antibody to hPS2, Abeta-42, caspase-3, and Cox-2 was visible in the brains of Tg mice compared with age-matched control mice, and 4) distinguishable AD phenotypes between hPS2w- and hPS2m-Tg mice did not appear. These results suggest that an elevation of Abeta-42 by overexpression of hPS2 and mutation of hPS2m might induce the behavioral deficit and caspase-3 and Cox-2 induction, which could be useful in the therapeutic testing of compounds to have considerable clinical effects.

No abstract

In oriental medicine, Liriope platyphylla (LP) has long been regarded as a curative herb useful for the treatment of diabetes, asthma, and neurodegenerative disorders. The principal objective of this study was to assess the effects of steaming time and frequency for manufactured Red LP (RLP) on insulin secretion ability and insulin receptor signaling pathway. To achieve our goal, several types of LPs manufactured under different conditions were applied to INS cells and streptozotocin (STZ)-induced diabetic ICR mice, after which alterations in insulin concentrations were detected in the culture supernatants and sera. The optimal concentration for the investigation of insulin secretion ability was found to be 50 ug/mL of LP. At this concentration, maximum insulin secretion was observed in the INS cells treated with LP extract steamed for 3 h (3-SLP) with two repeated steps (3 h steaming and 24 h air-dried) carried out 9 times (9-SALP); no significant changes in viability were detected in any of the treated cells. Additionally, the expression and phosphorylation levels of most components in the insulin receptor signaling pathway were increased significantly in the majority of cells treated with steaming-processed LP as compared to the cells treated with LP prepared without steaming. With regard to glucose transporter (GLUT) expression, alterations of steaming time induced similar responses on the expression levels of GLUT-2 and GLUT-3. However, differences in steaming frequency were also shown to induce dose-dependent responses in the expression level of GLUT-2 only; no significant differences in GLUT-3 expression were detected under these conditions. Furthermore, these responses observed in vitro were similarly detected in STZ-induced diabetic mice. 24-SLP and 9-SALP treatment applied for 14 days induced the down-regulation of glucose concentration and upregulation of insulin concentration. Therefore, these results indicated that the steaming processed LP may contribute to the relief of diabetes symptoms and should be regarded as an excellent candidate for a diabetes treatment.

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.