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171.
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ABSTRACT: As part of our study of the isolation of antihypertensive agents derived from natural marine products, the bioactivity of 10 edible Korean seaweeds were screened by angiotensin converting enzyme (ACE) inhibitory and peroxynitrite assays. Among the crude extracts of selected seaweeds, including five Phaeophyta ( Ecklonia stolonifera , E. cava , Pelvetia siliquosa , Hizikia fusiforme , and Undaria pinnatifida ), four Rhodophyta ( Gigartina tenella , Gelidium amansii , Chondria crassicaulis , and Porphyra tenera ) and one Chlorophyta ( Capsosiphon fulvescens ), the ethanol extracts of E. stolonifera , E. cava , P. siliquosa , U. pinnatifida , and G. tenella exhibited significant inhibitory properties against ACE at more than 50% inhibition at a concentration of 163.93 µg/mL. Phloroglucinol 1 , eckstolonol 2 , eckol 3 , phlorofucofuroeckol A 4 , and dieckol 5 had been isolated previously, and triphlorethol-A 6 and fucosterol 7 were isolated for the first time from E. stolonifera. Also, the ACE inhibitory and peroxynitrite scavenging properties of phlorotannins 1–6 were evaluated, along with fucosterol 7 obtained from E. stolonifera . Among profound peroxynitrite scavenging compounds 1–6 , phlorotannins 3 , 4 and 5 were also determined to manifest marked inhibitory activity against ACE, with 50% inhibition concentration (IC50 ) values of 70.82 ± 0.25, 12.74 ± 0.15, and 34.25 ± 3.56 µM, respectively. 相似文献
174.
Jun-Young Bae Gun Hyun Park Jeong-Yeol Lee Okorie Eme Okorie Sungchul C. Bai 《Aquaculture International》2012,20(3):513-523
This study was conducted to investigate the effects of dietary propolis supplementation on growth performance, immune responses, disease resistance and body composition of juvenile eel, Anguilla japonica, in order to evaluate its bioavailability as a feed additive for this species. A total of 540 fish averaging 7.7?±?0.22?g (mean?±?SD) were randomly distributed into 18 tanks in groups of 30, and each tank was then randomly assigned to one of three replicates of six diets containing 0 (P0), 0.25 (P0.25), 0.5 (P0.5), 1.0 (P1), 2.0 (P2) and 4.0 (P4) % dietary propolis. At the end of 12?weeks of feeding trial, weight gain (WG), specific growth rate (SGR), feed efficiency (FE) and protein efficiency ratio (PER) of fish fed P0.5 diet were significantly higher than those of fish fed P0, P1, P2 and P4 diets (P?<?0.05). These parameters were 148.9%, 0.72% day?1, 94.4% and 2.9, respectively for fish fed P0.5 diet. Serum lysozyme activity of fish fed P0.5 (105.7 units mL?1) and P1 (106.0 units mL?1) diets were significantly higher than those of fish fed P0, P0.25, P2 and P4 diets. Mucus lysozyme activity of fish fed P1 (8.4 units 10?cm?2) diet was significantly higher than those of fish fed P0, P2 and P4 diets. Results indicated that the optimum dietary propolis supplementation levels could be 0.25?C0.5% for optimum growth and feed efficiency, and 0.5?C1% for enhanced immune responses and disease resistance in eel, A. japonica. This study may suggest that the dietary propolis level for the optimum immune responses could be higher than the level for the optimum growth of eel. 相似文献
175.
Kim Hyun Kyung Kim Young Ho Kim Yun Ji Park Hyun Jin Lee Nam Hyouck 《Fisheries Science》2012,78(2):485-490
In this study we investigated the effects of ultrasonic wave treatment on the extraction yield of acid-soluble collagen from
sea bass skins. Two extraction methods were compared: a 24 h acid treatment using 0.5 M acetic acid (1:200 sample/acid, w/v)
and an extraction using ultrasonic treatment after the addition of a 0.5 M acetic acid solution. The results indicated that
the extraction yield of collagen increased with the ultrasonic treatment, with the extraction rate increasing rapidly at higher
amplitudes of ultrasonic treatment. The subunit compositions of the collagen extracted by ultrasonic treatment were analyzed
by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, which revealed that the α1(α3), α2, and β chains of collagen
were present early in the ultrasonic treatment. An unknown component, believed to be a product of collagen degradation induced
by the ultrasonic treatment, was detected only after a longer treatment time. The component extracted by the ultrasonic treatment
was determined to be collagen based on the finding that there were no changes in the main components of collagen, specifically,
the α1(α3), α2, and β chains, following pepsin treatment. 相似文献
176.
Since the oxidation of low-density lipoprotein (LDL) is one of the main causes of atherosclerosis, Cu2+-induced LDL oxidation and conjugated diene formation is currently being explored for the development of pharmaceutical drugs or functional foods for the treatment of atherosclerosis. The present work investigated the inhibitory effects on in vitro Cu2+-induced human LDL oxidation and conjugated diene formation of the methanol (MeOH) extract of the edible brown alga (Ecklonia stolonifera) and its different solvent-soluble fractions, as well as the phlorotannins isolated from them. The most active ethyl acetate fraction was selected for chromatographic separation to isolate six phlorotannins: phloroglucinol (1), dioxinodehydroeckol (2), eckol (3), phlorofucofuroeckol A (4), dieckol (5), and 7-phloroeckol (6). Compounds 3?C6 showed potent inhibitory activity against Cu2+-induced LDL oxidation as compared with probucol, a well-known clinical therapeutic agent for hypercholesterolemia. Moreover, when compound 5 (at levels of 9 and 4.5???M) was used in combination with probucol (4.5???M), they additively inhibited Cu2+-induced LDL oxidation. In addition, 3?C5 significantly prolonged the lag time of conjugated diene formation at 10???M. These results suggest that the potent antiatherosclerotic effects of E. stolonifera and its isolated phlorotannins may be partly attributed to the inhibition of Cu2+-induced LDL oxidation and conjugated diene formation. 相似文献
177.
Moo Sung Lee Min Gyu Ha Hyun Jin Ko Kap Seung Yang Wan Jin Lee Min Park 《Fibers and Polymers》2000,1(1):32-36
An alternative strategy to reduce the percolation threshold of carbon black (CB) in polymer blends was investigated using
random copolymer ternary blends of polystyrene (PS), poly(methyl methacrylate) (PMMA), and a styrene-methyl methacrylate random
copolymer (SMMA). The target morphology was to selectively locate CB particles in the encapsulating layer of SMMA during melt
mixing. The CB used in this study is BP-2000 from Cabot and has a strong selective affinity to PS. Even when the CB was premixed
with SMMA, it moves to the PS phase during the melt mixing. However, we also observed the CB particles located at the interface
between SMMA and PS phases. Through this study it is found that the interaction between polymers and CB particles is critical
for selectively localizing CB particles in multi-component polymer blends. Although appropriate processing condition may retard
the movement of CB particles to the polymer phase with affinity, it cannot prevent it completely and locate them to the SMMA
phase, which is not thermodynamically favored. To locate CB particles in an encapsulating layer of ternary polymer blends,
first of all, polymers forming it should have selective affinity to CB. 相似文献
178.
Hyun Soon Kim Jae Heung Jeon Kyung Hwa Choi Young Hee Joung Hyouk Joung 《American Journal of Potato Research》1999,76(1):5-8
Potato microtubers were treated with rindite to investigate the effect on dormancy breaking. Postharvest application of rindite by fumigation with 2 ml rindite for 48 hr or 4ml for 24 hr significantly reduced the dormancy period of potato microtubers using a 32 x 15 x 17 cm tightly sealed plastic box. Approximately 2 weeks after the treatments microtubers of all cultivars, Atlantic, Superior, Lemhi Russet, Red Dale and Kennebec started to sprout. The efficiency of the treatments were the greatest for the cv. Lemhi Russet, intermediate for cv. Superior and least for cv. Red Dale. In all cultivars of potato microtubers, more decay was observed the earlier rindite treatment occurred after harvesting, therefore potato microtubers should be treated with rindite at least 2 weeks after harvest when the skin of microtubers is mature. The data indicates that the dormancy of potato microtubers with well-matured skin can be effectively broken with an optimum treatment of rindite. 相似文献
179.
Jeong YG Chung SH Kim CT Kim KH Han SY Hyun BH Lee NS Sawada K Won MH Fukui Y 《Anatomia, histologia, embryologia》2006,35(2):111-115
The ataxic pogo mouse (pogo/pogo) is a novel neurological mutant, which was derived as an inbred strain (KJR/MsKist) from a Korean wild mouse. The pathological manifestations include a difficulty in maintaining a normal posture, the failure of inter-limb coordination and an inability to walk straight. In this study, we examined the distribution of corticotropin-releasing factor (CRF) immunoreactive cerebellar climbing fibres and their projections to tyrosine hydroxylase (TH) immunoreactive Purkinje cells in the cerebellum of the pogo mutant mouse using immunohistochemistry. In the pogo/pogo mouse, a subset of climbing fibres was stained more intensely for CRF than in the control. Moreover, ataxic pogo mouse, neurons of the inferior olivary nucleus projecting climbing fibres were also more intensely stained for CRF than in the control. In the pogo/pogo mouse, TH immunoreactivity was located in the Purkinje cells, whereas no TH expression was found in the control. Double immunostaining for CRF and TH in the pogo/pogo cerebellum revealed that the distribution of TH-immunoreactive Purkinje cells corresponded to terminal fields of CRF-immunoreactive climbing fibres but not to the CRF-immunoreactive mossy fibres. Therefore, we suggest that an increase of CRF level may alter the function of targeted Purkinje cells and that it is related to the ataxic phenotype in the pogo mutant mouse. 相似文献
180.