Acetyl- and butyrylcholinesterase inhibitory activities of sterols and phlorotannins from Ecklonia stolonifera

ABSTRACT:   As part of this study on the isolation of cholinesterase inhibitors from natural marine products, the bioactivity of the ethanolic extracts from 27 Korean seaweeds were screened using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory assays. Ecklonia stolonifera exhibited promising inhibitory properties against both AChE and BChE. Bioassay-guided fractionation of the active n -hexane and ethyl acetate (EtOAc) soluble fractions, obtained from the ethanolic extract of E. stolonifera , resulted in the isolation of the sterols; fucosterol ( 1 ) and 24-hydroperoxy 24-vinylcholesterol ( 2 ), from the n -hexane fraction and the phlorotannins; phloroglucinol ( 3 ), eckstolonol ( 4 ), eckol ( 5 ), phlorofucofuroeckol-A ( 6 ), dieckol ( 7 ), triphlorethol-A ( 8 ), 2-phloroeckol ( 9 ) and 7-phloroeckol ( 10 ), from the EtOAc fraction. Of these, compounds 2 , 9 and 10 were isolated from E. stolonifera for the first time. Compounds 4 – 7 , 9 and 10 exhibited inhibitory potential against AChE, with 50% inhibition concentration (IC₅₀) values of 42.66 ± 8.48, 20.56 ± 5.61, 4.89 ± 2.28, 17.11 ± 3.24, 38.13 ± 4.95 and 21.11 ± 4.16 μM, respectively; whereas, compounds 1 , 2 , 4 and 6 were found to be active against BChE, with IC₅₀ values of 421.72 ± 1.43, 176.46 ± 2.51, 230.27 ± 3.52 and 136.71 ± 3.33 μM, respectively. It has been suggested that the inhibition of these enzymes by the sterols and phlorotannins derived from marine brown algae could be a useful approach for the treatment of Alzheimer's disease.     

Distribution and migration of Japanese common squid, Todarodes pacificus, in the southwestern part of the East (Japan) Sea

Data on squid catches of Korean and Japan, water temperatures at depth of 100 m, and night-visible images of fishing boats collected in the East (Japan) Sea from 1970 to 1999 were analyzed to examine the distribution and migration of the Japanese common squid, Todarodes pacificus, in the southwestern part of the East (Japan) Sea. The main fishing grounds detected from squid catch in each grid (0.5° latitude × 0.5° longitude) by Korean squid fishery and night-visible images provided by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) were situated in the southwestern part of the East (Japan) Sea. The distribution and migration route was illustrated from squid catch in each grid and DMSP OLS image. In years of high catches, the fishing grounds were situated mainly between Ulleung Island and the eastern coastal waters of Korea, while in years of low catches they were situated between Ulleung Island and the Yamato Bank in the central East (Japan) Sea. The center of fishing activity began moving northward from around the Korea/Tsushima strait to the northern boundary of the Tsushima Warm Current in March, reaching into the Yamato Bank in September, and then returning to the strait by February. The northward and southward migration routes differed; the northward migration route occurred closer to the mainland coast of Korea than the southward migration route did. This work suggests T. pacificus begin their northward migration almost 2 months earlier than previously suggested.     

Exendin-4 improves resistance to Listeria monocytogenes infection in diabetic db/db mice

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b⁺ macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages.     

试论呼市地区园林植物五小害虫的发展状况和防治策略

本文在实地调查和试验研究的基础上，系统地分析了呼市地区园林植物五小害虫的发展状况，在初步查清主要危害虫种及其生物学特性基础上，提出了加强植物检疫，利用，保护天敌，加强生物防治的研究，适时采用物理防治方法，合理科学地应用化学防治法的综合防治策略，对化学杀虫剂的选择，使用浓度，施药时间和次数提出了科学有效的试验依据。     

杨树水泡型溃疡病菌生理特性的研究

 经试验杨树水泡型溃疡病菌分生孢子的萌芽不超过2小时。以2%葡萄糖溶液处理的孢子萌芽率最高为92.8%。冰箱保存14个月的分生孢子,经24小时的发芽率为73.5。     

Effects of green tea polyphenol (-)-epigallocatechin-3-gallate on newly developed high-fat/Western-style diet-induced obesity and metabolic syndrome in mice

The aim of this study was to investigate the effects of (-)-epigallocatechin-3-gallate (EGCG) on newly developed high-fat/Western-style diet-induced obesity and symptoms of metabolic syndrome. Male C57BL/6J mice were fed a high fat/Western-style (HFW; 60% energy as fat and lower levels of calcium, vitamin D(3), folic acid, choline bitartrate, and fiber) or HFW with EGCG (HFWE; HFW with 0.32% EGCG) diet for 17 wks. As a comparison, two other groups of mice fed a low-fat diet (LF; 10% energy as fat) and high-fat diet (HF; 60% energy as fat) were also included. The HFW group developed more body weight gain and severe symptoms of metabolic syndrome than the HF group. The EGCG treatment significantly reduced body weight gain associated with increased fecal lipids and decreased blood glucose and alanine aminotransferase (ALT) levels compared to those of the HFW group. Fatty liver incidence, liver damage, and liver triglyceride levels were also decreased by the EGCG treatment. Moreover, the EGCG treatment attenuated insulin resistance and levels of plasma cholesterol, monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP), interlukin-6 (IL-6), and granulocyte colony-stimulating factor (G-CSF). Our results demonstrate that the HFW diet produces more severe symptoms of metabolic syndrome than the HF diet and that the EGCG treatment can alleviate these symptoms and body fat accumulation. The beneficial effects of EGCG are associated with decreased lipid absorption and reduced levels of inflammatory cytokines.     

Topical tacrolimus (FK506) for the treatment of feline idiopathic facial dermatitis

A 3-year-old, neutered male Persian cat with chronic ulcerative facial dermatitis was diagnosed with feline idiopathic facial dermatitis based on signalment, clinical history and diagnostic test results, including dermatohistopathological evaluation. Initial treatment started with 4 weeks of oral antifungal/antibiotic medication for severe secondary infectious dermatitis of Malassezia and bacteria. As the lesions gradually improved, the oral medication was withdrawn, leaving only 0.1% topical FK506 (tacrolimus) ointment for the remaining lesions. Topical treatment was administered just in case any new lesions developed. The patient has been managed effectively with topical tacrolimus and no side-effects were observed during treatment. Feline idiopathic facial dermatitis is known as a difficult dermatosis to manage successfully, but our experience suggests that it may respond to topical tacrolimus.     

广州地区十字花科蔬菜花叶病的传染途径及流行规律的初步研究

广州地区十字花科蔬菜花叶病(主要病毒是芜菁花叶病毒的油菜毒系和芜菁毒系)的越夏寄主,根据11年来的观察特别是1956—1958年间的实地调查结果,主要是小白菜、菜心和西洋菜。在野生植物中曾发现过2株蔊菜和1株荠菜自然感病,说明野生植物不是本病的重要毒源。室内试验结果证明,此病的自然传染媒介为萝卜蚜、桃蚜和普通红蜘蛛。黄条跳(虫甲)、斜纹夜盗蛾和菜粉蝶都不是本病的虫媒,病株的种子不会传病,中国菟丝子也不会传递本病。在带有未腐熟的病菜残体的土里进行直播,长出来的菜苗没有发病的;但是把菜苗移植在这样的土里,会有极小量的植株感病。根据1956年7月至1958年6月,每十日田间调查一次结果:萝卜蚜是广州地区最重要的传病媒介,桃蚜每年只在3—4月间略有发生,作用不大。根据这24个月的田间发病率,萝卜蚜(有翅蚜及无翅蚜)的虫口密度和气候情况,我们认为本地区本病的发生及流行程度主要受降水量和降水天数所影响,并认为可以从降水情况来预测约30日后的病害流行程度。     

Biaxial Extensional Viscosity of Sheeted Noodle Dough

The flows encountered during the sheeting process contain a more extensional component and more stretching than simple shear. Evaluating the properties of the extensional rheological flow of wheat flour dough is essential to better understand the sheeting process and the final quality of the product. Our results show that the curves of biaxial extensional viscosity versus extensional strain rate for dough from different wheat cultivars including Dark Northern Spring (DNS), Hard Red Winter (HRW), and Western White Wheat (WW) with protein contents of 7.81–18.09% and water contents of 32–40% could be discriminated. During a lubricated compression test, the sheeted dough displayed a region of extensional thickening followed by a region of mild extensional thinning, giving rise to an s-shaped extensional stress-strain rate curve. The higher degree of extensional thinning was exhibited for the sheeted dough prepared from the flour of DNS and HRW wheat mixture with an extensional thinning index of n = 0.65–0.74; while the lower degree of extensional thinning was displayed for the DNS wheat with an extensional thinning index of n = 0.89–0.96. The data of biaxial extensional viscosity (η_Bmax) versus water content and protein content could be described by power relationships. The results suggest that biaxial extensional viscosity can be a useful modeling and process design parameter that objectively represents the rheological properties during dough sheeting.