Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Young-Ju Choi is active.

Publication


Featured researches published by Young-Ju Choi.


Journal of Life Science | 2008

Mineral Contents and Physiological Activities of Dried Sea Tangle (Laminaria japonica) Collected from Gijang and Wando in Korea.

Jae-Suk Choi; Su-Hwa Shin; Yu-Mi Ha; Yang-Chun Kim; Tae-Bong Kim; Sun-Mee Park; In-Soon Choi; Hyo-Ju Song; Young-Ju Choi

This research was performed to determine the proximate compositions, mineral contents, alginic acid, antioxidative activities and amino acids of sea tangles collected from Gijang and Wando area. Crude protein and ash contents were higher in Gijang sea tangle, whereas carbohydrate and moisture were higher in Wando in general. Mineral contents of Gijang sea tangle were higher than Wando. Especially, Na and K was the most abundant in both Gijang and Wando sea tangles. Alginic acid content was almost similar in both sea tangles. The major free amino acids were glutamic acid, aspartic acid, alanine, proline and hydroxyproline in both Gijang and Wando sea tangles. Antioxidative activity of methanol extract of sea tangle was measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activity were about 17% (40 ㎍/㎖) and 7% (5 ㎍/㎖) higher, respectively, in Wando sea tangle. When stimulate the macrophages RAW264.7 cells with lipopolysaccharide (LPS), inhibition of NO synthesis of the methanol extract was 11% higher in Wando sea tangle comparing with Gijang samples.


Journal of Life Science | 2011

Inhibitory Effects of Maesaengi (Capsosiphon fulvescens) Extracts on Angiotensin Converting Enzyme and α-Glucosidase

Eun-Kyung Cho; Seul-Ki Yoo; Young-Ju Choi

Physiological activities of hot water (MHW) and 80% ethanol (MEH) extracts from Maesaengi (Capsosiphon fulvescens) were investigated in this study. For the evaluation of antioxidant activities for MHW and MEH, 2,2-diphenyl-1-pic-rylhydrazyl (DPPH) radical scavenging activity and superoxide dismutase (SOD)-like activity were measured. DPPH radical scavenging activity and SOD-like activity of MHW, and MEH were increased weekly in a dose-dependent manner, and were about 10.8, 13.8, 62.4, and 27.1% at 10 mg/ml, respectively. The angiotensin converting enzyme (ACE) inhibitory activities of MHW and MEH were about 5.9% and 49.7% at 1 mg/ml, respectively. The -glucosidase inhibitory effect of MHW and MEH were about 1.4% and 67.3% at 1 mg/ml, respectively. To determine the influence of MHW and MEH on alcohol metabolizing activity, the generating activities of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) were measured. Facilitating rates of ADH activity by MHW and MEH were increased weekly in a dose-dependent manner and ALDH activities were not detected. Elastase inhibitory activities of MHW and MEH were 75.9% and 51.2% at 10 mg/ml, respectively.


Journal of Life Science | 2007

Antimicrobial and Antioxidant Activities and Inhibition of Nitric Oxide Synthesis of Oak Wood Vinegar

Il-Sun Jung; Yu-Jung Kim; Sang-Wan Gal; Young-Ju Choi

This study was carried out to investigate the biological effects oak wood vinegar. Antimicrobial activity was tested in five microbial species at the concentration of 5 to 50 ㎕ of oak wood vinegar by paper disc method. Growth of P. oleovoranse, P. vulgaris, E. coli, S. aureus and Prevotella intermedia was inhibited at a dose of as low as 50 ㎕ of oak wood vinegar. Antioxidant activities were measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging and SOD-like activities were 90% and 65% at the concentration of 25 ㎕ and 50 ㎕ of oak wood vinegar, respectively. Stimulation of the macrophages RAW264.7 cells with lipopolysaccharide (LPS) resulted in increased production of nitric oxide (NO) in the medium. However, the oak wood vinegar showed marked inhibition of NO synthesis in a dose-dependent manner. This result suggest that oak wood vinegar plays significant role for activation of immune system in the pathogenesis of inflammatory diseases.


Journal of Life Science | 2009

Inhibitory Effects of Ethanol Extracts from Pine Buds (Pinus densiflora) on Angiotensin Converting Enzyme, Xanthine Oxidase and Nitric Oxide Synthesis

Eun-Kyung Cho; Hyo-Ju Song; Hea-Eun Cho; Mihyang Kim; In-Soon Choi; Young-Ju Choi

Pine trees (Pinus densiflora Sieb. et Zacc.) have been used as a traditional health-promoting medicinal food in Korea. This research was performed to determine the antioxidative and antibacterial activities, tyrosinase, nitric oxide synthesis, angiotensin converting enzyme (ACE), and xanthine oxidase inhibition effects of the pine bud ethanol extract (PBE). Antioxidative activities of PBE were measured by using 2,2-diphenyl- 1-picryl-hydrazyl (DPPH) free radical scavenging activity and superoxide dismutase-like activity (SODA). DPPH radical scavenging and SOD-like activities of PBE were remarkably increased in a dose-dependent manner, and were about 88.9% and 47.9% at 1 ㎎/㎖ and 10 ㎎/㎖, respectively. The xanthine oxidase and angiotensin converting enzyme activities were inhibited about 71.9% and 60.8% at 1 ㎎/㎖ and 100 ㎍/㎖ of PBE, respectively. The tyrosinase inhibitory activities of PBE were slightly increased in a dose-dependent manner. The PBE showed strong antimicrobial activities on Escherichia coli (E. coli) and Vibrio paraheamolyticus. Stimulation of the macrophages RAW264.7 cells with lipopolysaccharide (LPS) resulted in increased production of nitric oxide (NO) in the medium. However, NO synthesis was reduced up to 54% by addition of PBE at 200 ㎍/㎖. These results revealed that pine buds have a strong antioxidative and anti-inflammatory activity, and exhibit angiotensin converting enzyme and xanthine oxidase inhibitory activities. This suggests that pine buds have the greatest property as a source for natural health products.


Journal of Life Science | 2008

Nutritional Composition and Biological Activities of the Methanol Extracts of Sea Mustard (Undaria pinnatifida) in Market.

Jae-Suk Choi; Hee-Jung Bae; Yang-Chun Kim; Nam-Hee Park; Tae-Bong Kim; Young-Ju Choi; Eun-Young Choi; Sun-Mee Park; In-Soon Choi

This research was performed to determine the proximate compositions, mineral contents, alginic acid, antioxidative activities and amino acids of sea mustards (Miyeok: Undaria pinnatifida) collected from Gijang and Wando area. Ash content was higher in Gijang samples, whereas carbohydrate and moisture were higher in Wando Sil Miyeok. General compositions of dried sea mustard showed different contents as manufactures company and places. The major free amino acids were hydroxyproline, alanine, glutamic acid and asparagine in Gijang samples. Both Gijang and Wando Sil Miyeok showed lower contents comparing with Gijang Gadak Miyeok. Major mineral content was Na, K, Ca, Mg and P, and especially, Na and K were the most abundant in both Gijang and Wando sea mustards. Alginic acid content was almost similar in both sea mustards. Antioxidative activity of methanol extract of sea mustards was measured by using DPPH radical scavenging and SOD-like activity. DPPH radical scavenging activity was 45.5% (40 ㎍/ml) in Gijang Gadak Miyeok and 37.0% and 26.0% (40 ㎍/ml) in Gijang and Wando Sil Miyok, respectively. SOD-like activity of Gijang and Wando Sil Miyok was 63% and 71% (10 ㎍/ml), respectively. These results show that biological activities depend on Miyeok manufactures process. When stimulated macrophages RAW264.7 cells with lipopolysaccharide (LPS), inhibition of NO production in Gijang Sil Miyeok (44.2%) was 9% high comparing with that of Wando Sil Miyeok (35.7%).


Journal of Life Science | 2007

Studies on Antioxidant Activity and Inhibition of Nitric Oxide Synthesis of Germinated Brown Rice Soaked in Mycelial Culture Broth of Phellinus linteus

Il-Sun Jung; Yu-Jung Kim; In-Soon Choi; Eun-Young Choi; Su-Hwa Shin; Sang-Wan Gal; Young-Ju Choi

This study investigated the effects on the biological activities of germinated brown rice soaked in mycelial culture broth of Phellinus linteus. The level of free amino acid was higher in the GBRP extract than those of BR and GBR. The major free amino acids were alanine, valine, isoleucine and methionine in both extracts. The level of -aminobutyric acid (GABA) was also increased significantly in the GBR and GBRP. Antioxidant activities of methanol extract of BR, GBR and GBRP were measured by using DPPH radical scavenging and SOD-like activity. Antioxidant activities showed the highest level of 83% and 76% when 100 mg/ml GBR and GBRP, respectively. Stimulation of the macrophages RAW264.7 cells with lipopolysaccharide (LPS) resulted in increased production of nitric oxide (NO) in the medium. However, the methanol extract of GBR and GBRP showed marked inhibition of NO synthesis in a does-dependant manner. These results showed that GBR and GBRP were significant role for activation of immune system in the pathogenesis of inflammatory diseases.This study investigated the effects on the biological activities of germinated brown rice soaked in mycelial culture broth of Phellinus linteus. The level of free amino acid was higher in the GBRP extract than those of BR and GBR. The major free amino acids were alanine, valine, isoleucine and methionine in both extracts. The level of γ-aminobutyric acid (GABA) was also increased significantly in the GBR and GBRP. Antioxidant activities of methanol extract of BR, GBR and GBRP were measured by using DPPH radical scavenging and SOD-like activity. Antioxidant activities showed the highest level of 83% and 76% when 100 ㎎/㎖ GBR and GBRP, respectively. Stimulation of the macrophages RAW264.7 cells with lipopolysaccharide (LPS) resulted in increased production of nitric oxide (NO) in the medium. However, the methanol extract of GBR and GBRP showed marked inhibition of NO synthesis in a does-dependant manner. These results showed that GBR and GBRP were significant role for activation of immune system in the pathogenesis of inflammatory diseases.


Journal of Life Science | 2008

Study of Deep Ground Sea-Like Water on Antioxidant Activity and the Immune Response in RAW264.7 Macrophages.

Yu-Jung Kim; Il-Sun Jung; Hyo-Ju Song; Eun-Young Choi; In-Soon Choi; Young-Ju Choi

Korean Deep ground sea-like water (KDSW) has a similar mineral composition with deep sea water. KDSW has demonstrated its usefulness and attracted in the medical fields. KDSW and Danasoo (desalted deep ground sea-like water) intake improve antioxidant, antidiabetic activity and immunity. Antioxidant activities of KDSW and Dnansoo were measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical, superoxide dismutase-like activity (SODA) and photochemiluminescence (PCL). DPPH radical scavenging and SOD-like activities of KDSW and Danasoo were remarkably increased in a dose-dependent manner. Antioxidant activities of KDSW and Danasoo 85.32 and 14.02 nmol of ascorbic acid equivalent/ml KDSW and Danasoo, respectively, using the PCL method. Lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages RAW264.7 cells was inhibited up to 30% by treatment with Danasoo (20%). NO is synthesized by the enzyme of nitric oxide synthase (NOS) and plays an important role tumor growth and angiogenesis. The anticancer effects of Danasoo on human gastric and lung cancer cells was performed by levels of inducible nitric oxide synthase (iNOS). Danasoo significantly reduced iNOS expression of human gastric cancer (SNU-l) and lung carcinoma (A549). The serum glucose level was significantly reduced by Danasoo (20%) diet in streptozotocin (STZ)-induced diabetic rats. These result suggest that KDSW has excellent biological activities and thus it has great potential as a source for natural health products.


Journal of Life Science | 2007

The Effect of Mulberry Fruits Extracts on Blood Flow Improvement in Ovariectomized Rats

Kyung-Ha Choi; Jae-Hak Shon; In-Soon Choi; Young-Ju Choi; Song-Ja Bae; Mihyang Kim

The purpose of this study was to investigate the effect of three different mulberry cultivars extracts on inhibition of platelet aggregation and blood flow improvement. Four groups were surgically ovariectomized (OVX). The fifth group was sham operated. Sprague-Dawley strain female rats were randomly assigned to the following groups : sham-operated rats(Sham), ovariectomized control rats(OVX-Control), ovariectomized rats supplemented with 80% ethanol extracts from fruits of Tajikistan mulberry (OVX-TM), Korea mulberry (OVX-KM) and China mulbery (OVX-CM) at 200 ㎎/㎏ bw/d. The mulberry extracts were orally administrated at 1 ml per day. The body weights of OVX rats were significantly heavier than the sham-operated rats at all values (p<0.05). The serum triglyceride level was significantly decreased after supplemented with the CM and KM extracts. The serum HDL-cholesterol level in the OVX-KM group was significantly higher than that in the OVX-control group. The passage time of whole blood showed significant correlation with triglyceride but reverse correlation with HDL cholesterol. The ability of platelet aggregation of groups treated with mulberry extracts was less than OVX-control group. Taken these together, mulberry extracts may be used to possibly improve the quality of life in menopausal women.


Journal of Life Science | 2008

Purification and Properties of a Novel Extracellular Agarase from Marine Bacterium, Sphingomonas paucimobilis AS-1

Il-Sun Jung; Yu-Jung Kim; Hyo-Ju Song; Sang-Wan Gal; Young-Ju Choi

An agar-degrading marine bacterium, strain AS-1 was isolated from the seawater. The strain AS-1 was identified as Sphingomonas paucimobilis (90% probability) by VITEK. The optimum medium for agarase activity of the isolated strain was determined to be marine medium, marine broth 2216 containing 0.1% agar as carbon source. An extracellular agarase was purified 104-fold from the culture supernatant by ammonium sulfate precipitation, ion exchange chromatography and gel filtration methods. The molecular weight of the purified enzyme was estimated to be 80 kDa by SDS-PAGE. The optimum pH and temperature for activity were 7.0 and , respectively. Antioxidative activity of the strain AS- was 72% in the supernatant cultured for 12 h. The culture supernatant of the strain AS-1 showed antibacterial activity against bacteria causing putrefaction and food poisoning such as Escherichia coli, Staphylococcus aureus and Proteus vulgaris. However, the cell growth of the lactic aicd forming strain, Lactobacillus plantarium was promoted by the treatment of 10% culture supernatant of an agar-degrading strain.


Journal of Life Science | 2009

Isolation and Characterization of Bacillus licheniformis SC082 Degrading Fibrin and Chitin from Shrimp Jeot-Gal

Eun-Kyung Cho; Yu-Jung Jung; Sang-Wan Gal; Young-Ju Choi

Shrimp Jeot-Gal is a popular traditional Korean fermented seafood and has been used for seasoning. We isolated a bacterium showing strong extra-cellular fibrinolysis and chitinase activity from shrimp Jeot-Gal and the strain was designated SC082. SC082 was identified as Bacillus licheniformis by 16S rRNA sequence homology search. B. licheniformis SC082 exhibited optimum temperature, pH, and salt concentration at , pH 7.0, and 6%, respectively. Substrate specificity of the culture supernatant from B. licheniformis SC082 was detected in fibrin, skim milk, and chitin plate. The fibrinolytic activity was highly maintained up to at a pH of 7.0 for 3 hr and was stable up to pH 9.0 at for 3 hr. The chitinase activity was remarkably induced by addition of 1.0% colloidal chitin and the pH and temperature optima of the enzyme were 5.0 and , respectively. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram analysis, this strain produced three fibrinolytic isozymes and two chitinase isozymes. The approximate molecular weights of the putative fibrinolytic enzymes were 23.0, 62.0, and 72.0 kDa and those of the chitinases were 62.0 and 55.0 kDa, respectively. The antioxidant activity of SC082 was also measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical. The DPPH radical scavenging was slightly increased in a dose-dependent manner.

Collaboration


Dive into the Young-Ju Choi's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Jae-Suk Choi

Pukyong National University

View shared research outputs
Top Co-Authors

Avatar

Sun-Mee Park

Pukyong National University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Mihyang Kim

Queen's University Belfast

View shared research outputs
Researchain Logo
Decentralizing Knowledge