Ultrafine Angelica gigas Powder Normalizes Ovarian Hormone Levels and Has Antiosteoporosis Properties in Ovariectomized Rats: Particle Size Effect

Kyeong Ok Choi,이인애,Sae-Yeol-Rim Paik,김동은,Jung Dae Lim,강위수,고상훈 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.10

The root of Angelica gigas (Korean angelica) is traditionally used to treat women's ailments that are caused by an impairment of menstrual blood flow and cycle irregularities. This study evaluated the effect particle size of Korean angelica powder on its efficacy for treating estrogen-related symptoms of menopause. Initially, Korean angelica roots were pulverized into ultrafine powder, and orally administered to the rats at a concentration of 500 mg/kg body weight for 8 weeks. The effects of Korean angelica powder particle size on extraction yield, contents of bioactive compounds (decursin and decursinol angelate), levels of serum ovarian hormones (estradiol and progesterone), reproductive hormones (luteinizing hormone and follicle-stimulating hormone), and experimental osteoporosis parameters (mineral density, strength, and histological features) were determined. A significant increase (fivefold) in the contents of decursin and decursinol angelate in the extract of the ultrafine Korean angelica powder was observed compared to coarse Korean angelica powder. Rats were divided into sham-operated or ovariectomized (OVX) groups that were fed coarse (CRS) or ultrafine (UF) ground Korean angelica root. The serum levels of estradiol in the OVX_UF group were 19.2% and 54.1% higher than that of OVX_CRS group. Serum bone-alkaline phosphatase/total-alkaline phosphatase index in the OVX_UF group was half that of the OVX_CRS group. In addition, less trabecular bone loss and thick cortical areas were observed in rats administered ultrafine powder. Therefore, ultrafine grinding may enhance the bioactivity of herbal medicines and be especially useful when their extracted forms lose bioactivity during processing, storage, and oral intake.

Shape- and size-controlled synthesis of noble metal nanoparticles

Choi, Kyeong Woo,Kim, Do Youb,Ye, Seong Ji,Park, O Ok Techno-Press 2014 Advances in materials research Vol.3 No.4

Noble metal nanoparticles (mainly Au, Ag, Pt and Pd) have received enormous attention owing to their unique and fascinating properties. In the past decades, many researchers have reported methods to control the shape and the size of these noble metal nanoparticles. They have consequently demonstrated outstanding and tunable properties and thus enabled a variety of applications such as surface plasmonics, photonics, diagnostics, sensing, energy storage and catalysis. This paper focuses on the recent advances in the solution-phase synthesis of shape- and size-controlled noble metal nanoparticles. The strategies and protocols for the synthesis of the noble metal nanoparticles are introduced with discussion of growth mechanisms and important parameters, to present the general criteria needed for producing desirable shapes and sizes. This paper reviews their remarkable properties as well as their shape- and size- dependence providing insights on the manipulation of shape and size of metal nanoparticles, necessary for appropriate applications. Finally, several applications using the shape- and size-controlled noble metal nanoparticles are highlighted.

Bupivacaine-induced Vasodilation Is Mediated by Decreased Calcium Sensitization in Isolated Endothelium-denuded Rat Aortas Precontracted with Phenylephrine

Ok, Seong Ho,Bae, Sung Il,Kwon, Seong Chun,Park, Jung Chul,Kim, Woo Chan,Park, Kyeong Eon,Shin, Il Woo,Lee, Heon Keun,Chung, Young Kyun,Choi, Mun Jeoung,Sohn, Ju Tae The Korean Pain Society 2014 The Korean Journal of Pain Vol.27 No.3

Background: A toxic dose of bupivacaine produces vasodilation in isolated aortas. The goal of this in vitro study was to investigate the cellular mechanism associated with bupivacaine-induced vasodilation in isolated endothelium-denuded rat aortas precontracted with phenylephrine. Methods: Isolated endothelium-denuded rat aortas were suspended for isometric tension recordings. The effects of nifedipine, verapamil, iberiotoxin, 4-aminopyridine, barium chloride, and glibenclamide on bupivacaine concentration-response curves were assessed in endothelium-denuded aortas precontracted with phenylephrine. The effect of phenylephrine and KCl used for precontraction on bupivacaine-induced concentration-response curves was assessed. The effects of verapamil on phenylephrine concentration-response curves were assessed. The effects of bupivacaine on the intracellular calcium concentration ($[Ca^{2+}]_i$) and tension in aortas precontracted with phenylephrine were measured simultaneously with the acetoxymethyl ester of a fura-2-loaded aortic strip. Results: Pretreatment with potassium channel inhibitors had no effect on bupivacaine-induced relaxation in the endothelium-denuded aortas precontracted with phenylephrine, whereas verapamil or nifedipine attenuated bupivacaine-induced relaxation. The magnitude of the bupivacaine-induced relaxation was enhanced in the 100mM KCl-induced precontracted aortas compared with the phenylephrine-induced precontracted aortas. Verapamil attenuated the phenylephrine-induced contraction. The magnitude of the bupivacaine-induced relaxation was higher than that of the bupivacaine-induced $[Ca^{2+}]_i$ decrease in the aortas precontracted with phenylephrine. Conclusions: Taken together, these results suggest that toxic-dose bupivacaine-induced vasodilation appears to be mediated by decreased calcium sensitization in endothelium-denuded aortas precontracted with phenylephrine. In addition, potassium channel inhibitors had no effect on bupivacaine-induced relaxation. Toxic-dose bupivacaine-induced vasodilation may be partially associated with the inhibitory effect of voltage-operated calcium channels.

Mono-Palmitoyl Isoflavone Show ed Enhanced Solubility and Strong Anti-Inflammatory Activities

Kyeong-hwan HWANG,Dong-hyun KIM,Hyun-kyung CHOI,Eun-ok LEE,Chang Seo PARK 한국생물공학회 2010 한국생물공학회 학술대회 Vol.2010 No.4

Regional Realtime Ocean Tide and Storm-surge Simulation for the South China Sea

Kyeong Ok Kim(김경옥),Byung Ho Choi(최병호),Han Soo Lee(이한수),Jin-Hee Yuk(육진희) 한국해안해양공학회 2018 한국해안해양공학회 논문집 Vol.30 No.2

남중국해는 심해 분지, 대륙 붕단, 얕은 대륙붕, 많은 해협, 복잡한 수심 특징을 가진 전형적인 연안 영해이다. 본 연구에서는, 비구조 격자 기반으로 대상 해역을 상세하게 해상할 수 있으며, 개방경계에 조석을, 해표면에 기상자료를 입력하여 조석 및 폭풍해일을 모의할 수 있는 수치 모델을 구축하여 남중국해의 조석 특성과 전파 양상을 조사하고, 태풍에 의한 폭풍해일을 재현하였다. 태풍에 의한 폭풍해일 모의는, 2013년에 필리핀에 막대한 피해를 초래하였던 태풍 하이옌에 대해서 수행하였다. 관측치 및 선행 연구의 조석 분포와의 비교 결과, 4개의 주요 분조의 진폭과 위상은 대체적으로 잘 모의되었다. 선행 연구들에 따르면, 당 해역은 모델을 이용하여 조석을 예측하기가 어렵다고 보고되고 있는데, 이 점을 감안한다면 본 연구에서 예측한 조석은 허용 범위에 있다고 생각된다. 본 연구에서 수행한 자유 진동 모드 실험을 통해서 남중국해가 일주조 조석이 우세한 이유를 알 수 있었으며, 조석 잔차류(tidal residual current) 및 총에너지 소실(total energy dissipation) 산정을 통해서 조석 및 퇴적환경을 파악하였다. 본 연구에서 구축한 모델을 이용하여 태풍 하이옌에 의한 폭풍해일을 타당하게 모의하였으며, 모델 검증 및 조석 환경 규명을 통하여 남중국해의 지역 실시간 순압 조석/수위 예측 시스템을 구축하였다. The South China Sea (SCS) is a typical marginal sea characterized with the deep basin, shelf break, shallow shelf, many straits, and complex bathymetry. This study investigated the tidal characteristics and propagation, and reproduced typhoon-induced storm surge in this region using the regional real-time tide-surge model, which was based on the unstructured grid, resolving in detail the region of interest and forced by tide at the open boundary and by wind and air pressure at the surface. Typhoon Haiyan, which occurred in 2013 and caused great damage in the Philippines, was chosen as a case study to simulate typhoon"s impact. Amplitudes and phases of four major constituents were reproduced reasonably in general, and the tidal distributions of four constituents were similar to the previous studies. The modelled tide seemed to be within the acceptable levels, considering it was difficult to reproduce the tide in this region based on the previous studies. The free oscillation experiment results described well the feature of tide that the diurnal tide is prevailing in the SCS. The tidal residual current and total energy dissipation were discussed to understand the tidal and sedimentary environments. The storm-surge caused by typhoon Haiyan was reasonably simulated using this modeling system. This study established the regional real-time barotropic tide/water level prediction system for the South China Sea including the seas around the Philippines through the validation of the model and the understanding of tidal characteristics.

The Role of the Immune System in the use of Probiotic Lactic Acid Bacteria in Preventing and Treating Allergic Diseases

Choi, Kyeong-Ok,Nguyen, Hoang-Hai,Kwak, Hae-Soo Korean Society for Food Science of Animal Resource 2010 한국축산식품학회지 Vol.30 No.1

The immune system is generally divided into the innate and the adopted immune systems, both protecting the body from pathogens. Recently, allergies, a disease associated with an imbalanced immune system, have increased rapidly in developed countries. Prevailing symptoms of allergic diseases are eczema, allergic rhinitis, asthma, inflammatory bowel disease, and food allergy. Probiotic bacteria, mainly consisting of lactic acid bacteria, are used in the prevention and treatment of allergic diseases. The function of them is to stimulate the intestinal immune cells and form a complex signal network to activate other immune cells. Beneficial health effects of probiotics are based on the hygiene hypothesis, which suggests that sanitary environment is important for health, but limited exposure to environmental factors increases allergic diseases. An immunoregulatory effect of probiotic bacteria is demonstrated by controlled trial, animal model, in vitro, in vivo and ex vivo designs. However, the immunoregulatory effect of probiotic bacteria is controversial because it depends on probiotic strains, a dose and a type of diseases. In this review, we discussed clinical evidences on immunoregulatory effects of probiotic bacteria.

Spray-dried Conjugated Linoleic Acid Encapsulated with Maillard Reaction Products of Whey Proteins and Maltodextrin

Kyeong-Ok Choi,Jina Ryu,Hae-Soo Kwak,고상훈 한국식품과학회 2010 Food Science and Biotechnology Vol.19 No.4

Encapsulation performance of Maillard reaction products (MRPs) produced by whey proteins and maltodextrin were examined for microencapsulation of conjugated linoleic acid (CLA) using spray-drying. CLA was encapsulated using 3 different wall materials containing a single constituent such as whey protein concentrate (WPC), whey protein isolate (WPI), and maltodextrin (MD), and 4 different MRPs. For the development of MRPs, ratios of WPC to MD were 1:2 and 1:3, whereas those of WPI to MD were 1:5 and 1:10. CLA and wall material were mixed and homogenized, and then spraydried. The physical properties of encapsulated CLA powders were characterized by particle size and morphology, ζ-potential, flowability, solubility, and dispersibility. The CLA powders coated with WPI-based MRPs have better encapsulation efficiency, water solubility, and smaller particle size than those coated with WPI, WPC, or MD alone. These encapsulated CLA powders have a number of possible utilities as ingredients in a variety of foods.

Functional enhancement of ultrafine <i>Angelica gigas</i> powder by spray-drying microencapsulation

Choi, Kyeong-Ok,Kim, Dongeun,Lim, Jung Dae,Ko, Sanghoon,Hong, Geun-Pyo,Lee, Suyong Elsevier 2019 FOOD SCIENCE AND TECHNOLOGY -ZURICH- Vol.101 No.-

<P><B>Abstract</B></P> <P>Whole <I>Angelica gigas</I> in a powder form has been limitedly utilized for food applications due to its undesirable processing performance such as low aqueous solubility and dispersibility. Ultrafine <I>Angelica gigas</I> powders were thus microencapsulated with maltodextrin (MD) at different mass ratios (1:1, 1:2 and 1:3, w/w) by spray-drying to enhance their functional characteristics. The microencapsulated <I>Angelica gigas</I> powders had a smaller particle size and a smoother surface than the native ones, and their particle size had a tendency to decrease with increasing proportions of microencapsulating materials. Significantly higher bulk density and lower moisture content (p < 0.05) were observed in the microencapsulated <I>Angelica gigas</I> powders than the native ones. The microencapsulation significantly improved the water solubility and dispersibility of the <I>Angelica gigas</I> powders (p < 0.05). In addition, two fold higher contents of decursin and decursinol angelate were significantly included from the microencapsulated <I>Angelica gigas</I> powders (p < 0.05). The results indicated that the microencapsulation with MD by spray-drying could be effective in enhancing the functional characteristics of <I>Angelica gigas</I> powders, showing the potential uses of the microencapsulated <I>Angelica gigas</I> powders in a food system.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ultrafine <I>Angelica gigas</I> (AG) powders were microencapsulated with maltodextrin (MD). </LI> <LI> Particle size of microencapsulated AG decreased with increasing levels of MD. </LI> <LI> Higher bulk density and lower moisture content were observed in microencapsulated AG. </LI> <LI> Microencapsulation improved the water solubility and dispersibility of AG powders. </LI> <LI> Microencapsulated AG had two fold higher contents of decursin and decursinol angelate. </LI> </UL> </P>

Improving Solubility through Carboxymethylation of Different-sized Endosperm, Bran, and Husk Rice Powders

Kyeong Ok Choi,Seung Cheol Yang,Dong Eun Kim,Wie-Soo Kang,Malshick Shin,Yoon-Hee Choi,Sanghoon Ko 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.6

The surfaces of different-sized endosperm, bran, and husk rice powders were modified using carboxymethylation. Carboxymethylation was carried out using aqueous alkalization and neutralization. After the carboxymethylation process, the centrifuged products were milled and classified by size: particles passed through sieves of 45, 106, and 300-㎛ width. The effect of carboxymethylation on physical properties such as solubility and dispersibility of endosperm, bran, and husk particles were studied. Overall, carboxymethylation increased solubility of the particles, while size reduction increased dispersibility. In particular, carboxymethylation created good aqueous suspensions by minimizing interparticle agglomeration. Our results show that the combination of size reduction and carboxymethylation improves solubility and dispersibility, resulting in better stability of the suspension. This study may be helpful for expanding the use of rice and its byproducts as ingredients in a variety of food and beverage applications.

Inhibitory Effects of Panaxatriol from Panax ginseng C. A. Meyer on Phosphoinositide Breakdown Induced by Thrombin in Platelets

Kyeong-Mee Park,Man-Hee Rhee,Han-Jae Shin,Yong-Bum Song,Hak-Chul Hyun,Ki-Hyun Park,Hyun-Jeong Cho,Sun-A Choi,Hyo-Chan Kang,Kyoung Jin Kim,Hyeong-Soo Kim,Hee-Jin Kang,Woo-Jeong Ok,Dong-Ha Lee,Hwa-Jin P 고려인삼학회 2008 Journal of Ginseng Research Vol.32 No.2

In this study, we have investigated the effect of panaxatriol (PT) on phosphoinositides (PIS) breakdown and Ca<SUP>2+</SUP>-elevation in thrombin-induced platelet aggregation. Thrombin (5U/ml), a potent platelet agonist which activates phospholipase Cβ via protease activated receptor (PAR), hydrolyzed PIS in platelet membrane. The phosphatidylinositol 4, 5-bisphosphate (PIP₂) was hydrolyzed after 10 sec of the thrombin-stimulation, and both the phosphatidylinositol 4-monophosphate (PIP) and phosphatidylinositol (PI) were brokendown after 30 sec of the thrombin-stimulation. However, PT inhibited the thrombin-stimulated hydrolysis of PIP₂, PIP, and PI. On the other hand, thrombin increased the level of phosphatidic acid (PA) which is phosphorylated from diacylglycerol (DG) generated by PIS-hydrolysis. However, PT inhibited the thrombin-increased PA level non-significantly. Thrombin increased cytosolic free Ca<SUP>2+</SUP>[Ca<SUP>2+</SUP>]i) up to 72% as compared with control (30.8±0.9 nM) in intact platelet. However, PT (100 ㎍/ml) inhibited the thrombin-elevated [Ca<SUP>2+</SUP>]i to 100%. These results suggest that PT may have a beneficial effect on platelet aggregation-mediated thrombotic disease by inhibiting thrombin-induced platelet aggregation via suppression of the [Ca<SUP>2+</SUP>]i level and PIS breakdown.