• The Korea Journal of Herbology
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• v.34 no.1
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• pp.109-116
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• 2019

Objectives : This study aimed to analyze contents of chlorogenic acid among major ingredients and determine the optimal solvent for the antioxidant activity from Solidago virga-aurea var. gigantea(SV) aerial part. Methods : Mature aerial part of extracted SV at the first crop on June 2018 was used. SV was mixed with each at the ethanol concentrate rates of water, 10, 30, 50, 70, and 100% and extracted them for three times for eight hours at $70^{\circ}C$. The contents of chlorogenic acid and seven kinds of antioxidant activities were measured in SV extracts. Results : The highest the contents of chlorogenic acid was from 10% ethanol extracts showed. Total polyphenol and flavonoids of SV extracts were 126.16 mg/g and 105.84 mg/g, respectively. Scavenging activities of DPPH, ABTS, and hydroxyl radical significantly increased in a dose-dependent in SV extracts, while it was almost similar with control at the concentration of $500{\mu}g/mL$. $Fe^{2+}$ chelating activity significantly increase in a dose-dependent in SV extract, it was lower than control. Nitrite scavenging activity increased, dose-dependent in the sequence of pH 1.2> pH 3.0 > pH 6.0 in SV extracts, while it was almost similar with control at the concentration of $500{\mu}g/mL$, pH 1.2, and pH 3.0. Conclusions : Thus, this study found that higher contents of chlorogenic acid and excellent antioxidant activity were contained in 10% ethanol extracts in mature aerial part of SV. It is expected to be used as basic data as natural antioxidant materials.

• Journal of Environmental Science International
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• v.31 no.8
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• pp.715-725
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• 2022

Lactic Acid Bacteria (LAB) are among the representative probiotics that have been used for a long time in fermented food. Although there are many studies on detecting the radical scavenging activity of LAB, few studies have been conducted on the environmental factors that improve scavenging activity. This study investigated the environmental factors affecting the DPPH radical scavenging and various antioxidant activities of Kimchi-derived Lactobacillus plantarum K-21 with antihypertensive and radical scavenging activities. The optimal conditions for scavenging DPPH radicals were glucose 2%, bactopeptone 0.5%, Tween 80 0.05%, L-cysteine 0.05%, and an initial pH 6.5 at 35℃. Under optimal conditions, the DPPH radical scavenging activity was 94.8±2.2%, which was 1.5 times higher than that of the basic medium. In addition, L. plantarum K-21 had other antioxidant activities; ABTS radical scavenging (93.6±1.5%), hydroxyl radical scavenging (8.5±0.9%), metal chelating (65.9±0.5%), NO scavenging (53.1±19%), SOD-like (25.1±1.5%), and reducing power (11.7±1.4%) activities were detected. Therefore, L. plantarum K-21 may act not only as a starter for lactic acid-fermented foods with improved functionality but also as a drug for various diseases caused by oxidative stress.

• Journal of Audiology & Otology
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• v.23 no.2
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• pp.69-75
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• 2019

Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

• Korean Journal of Audiology
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• v.23 no.2
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• pp.69-75
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• 2019

Background and Objectives: The antioxidant ebselen will be able to limit or prevent the ototoxicity arising from 2-hydroxypropyl-β-cyclodextrin (HPβCD). Niemann-Pick Type C (NPC) disease is a disorder of lysosomal storage manifested in sphingolipidosis. Recently, it was noted that experimental use of HPβCD could partially resolve the symptoms in both animals and human patients. Despite its desirable effect, HPβCD can induce hearing loss, which is the only major side effect noted to date. Understanding of the pathophysiology of hearing impairment after administration of HPβCD and further development of preventive methods are essential to reduce the ototoxic side effect. The mechanisms of HPβCD-induced ototoxicity remain unknown, but the resulting pathology bears some resemblance to other ototoxic agents, which involves oxidative stress pathways. To indirectly determine the involvement of oxidative stress in HPβCD-induced ototoxicity, we tested the efficacy of an antioxidant reagent, ebselen, on the extent of inner ear side effects caused by HPβCD. Materials and Methods: Ebselen was applied prior to administration of HPβCD in mice. Auditory brainstem response thresholds and otopathology were assessed one week later. Bilateral effects of the drug treatments also were examined. Results: HPβCD-alone resulted in bilateral, severe, and selective loss of outer hair cells from base to apex with an abrupt transition between lesions and intact areas. Ebselen co-treatment did not ameliorate HPβCD-induced hearing loss or alter the resulting histopathology. Conclusions: The results indirectly suggest that cochlear damage by HPβCD is unrelated to reactive oxygen species formation. However, further research into the mechanism(s) of HPβCD otopathology is necessary.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.40-46
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• 2024

A novel approach is presented to address issues associated with the use of strong acidic solutions for the leaching of magnesium oxide (MgO) from spent magnesia-carbon refractories. An ultrasonic flotation and separation process is employed, with a mildly acidic solvent, acetic acid, used to selectively chelate MgO from the spent refractories. When using 2 M acetic acid as a solvent, the recovery of the graphite exhibited 99.7 % with high purity of 72.7 %, showing a significant improvement compared to using water as the solvent. Furthermore, the technology presented in this study offers a method for producing magnesium acetate through the reaction of MgO in spent refractory with acetic acid, providing a means for the purification and separation of graphite.

• Food Science of Animal Resources
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• v.44 no.3
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• pp.533-550
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• 2024

Peptides with bioactive effects are being researched for various purposes. However, there is a lack of overall research on pork-derived peptides. In this study, we reviewed the process of obtaining bioactive peptides, available analytical methods, and the study of bioactive peptides derived from pork. Pepsin and trypsin, two representative protein digestive enzymes in the body, are hydrolyzed by other cofactors to produce peptides. Bicinchoninic acid assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, chromatography, and in vitro digestion simulation systems are utilized to analyze bioactive peptides for protein digestibility and molecular weight distribution. Pork-derived peptides mainly exhibit antioxidant and antihypertensive activities. The antioxidant activity of bioactive peptides increases the accessibility of amino acid residues by disrupting the three-dimensional structure of proteins, affecting free radical scavenging, reactive oxygen species inactivation, and metal ion chelating. In addition, the antihypertensive activity decreases angiotensin II production by inhibiting angiotensin converting enzyme and suppresses blood pressure by blocking the AT1 receptor. Pork-derived bioactive peptides, primarily obtained using papain and pepsin, exhibit significant antioxidant and antihypertensive activities, with most having low molecular weights below 1 kDa. This study may aid in the future development of bioactive peptides and serve as a valuable reference for pork-derived peptides.

• Microbiology and Biotechnology Letters
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• v.44 no.2
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• pp.130-139
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• 2016

A bacterial strain, producing an excellent lipolytic enzyme, was isolated from the intestinal tracts of an earthworm (Eisenia fetida). The strain was identified as Aeromonas hydrophila by phenotypic, chemotaxonomic characteristics and 16S ribosomal DNA analysis, and was designated as Aeromona hydrophila PL43. The lipolytic enzyme from A. hydrophila PL43 was purified via 35−45% ammonium sulfate precipitation, DEAE-sepharose fast flow ion-exchange, and sephacryl S-300HR gel filtration chromatography. The yield of the purified enzyme was 3.7% and 2.5% of the total activity of crude extracts with p-nitrophenyl butyrate (pNPB) and p-nitrophenyl palmitate (pNPP) as substrates, respectively. The molecular weight of the purified enzyme was approximately 74 kDa using gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and zymography. The optimal activity of purified enzyme was observed at 50℃ and pH 8.0 using pNPB, and 60℃ and pH 8.0 using pNPP. The purified enzyme was stable in the ranges 20− 60℃ and pH 7.0−10.0. The activity of purified enzyme was inhibited by PMSF, pepstatin A, Co²⁺, Cu²⁺, and Fe²⁺, but was recovered by metal chelating of EDTA. The K_m and V_max values of the purified enzyme were 1.07 mM and 7.27 mM/min using pNPB and 1.43 mM and 2.72 mM/min using pNPP, respectively.

• Journal of Applied Biological Chemistry
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• v.53 no.1
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• pp.13-20
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• 2010

Biological activities such as anti-oxidative and anti-microbial of the Seungmakalgeuntang, a traditional prescription, were evaluated. The electron donating ability of water, ethanol, supercritical fluid and 1,3-butylene glycol extract of Seungmakalgeuntang showed more than 50% at a 100 ppm concentration. At a 1000 ppm concentration, the superoxide dismutase-like activities of ethanol and supercritical fluid extract of Seungmakalgeuntang showed less than 50%. xanthine oxidase inhibition effect of the supercritical fluid extract showed more than 70% at a 1,000 ppm concentration, which was higher than vitamin C. From the measurement on lipid oxidation, the $Fe^{2+}$ chelating abilities of the supercritical fluid extract of Seungmakalgeuntang was more than 60% at a 100 ppm concentration. Also the $Cu^{2+}$ chelating abilities of supercritical fluid extract Seungmkalgeuntang was showed more than 60% at a 500 ppm concentration. Clear zones formed by sample against the human skin-resident microflora such as Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acne of ethanol and supercritical fluid extract of Seungmakalgeuntang showed the highest among all the extracts tested using a 4mg/disc. The minimum inhibitory concentration (MIC) against both S. epidermidis and S. aureus showed 2,500 ppm in the extract of the supercritical fluid.

• Food Science and Preservation
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• v.18 no.2
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• pp.236-243
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• 2011

We evaluated the nutritional value of 70% ethanol extracts (EE) from fermented cudrania tricuspidata fruit (ECT: EE of C. tricuspidata, EFCT: EE of fermented C. tricuspidata, EFCTL: EE of fermented C. tricuspidata by B. licheniformis, EFCTS: EE of fermented C. tricuspidata by B. subtilis) by determined the total polyphenol and flavonoid contents, antioxidant activities, and inhibitory actions on elastase and tyrosinase. The yields of freeze-dried powder of ECT, EFCT, EFCTL, and EFCTS were 54.22%, 54.43%, 57.51%, and 57.23% (each w/w), respectively. The color of $L^*,\;a^*,\;b^*$ values decreased of fermented cudrania tricuspidata. The fermented EFCTL and EFCTS had relatively higher contents of total polyphenol and flavonoid than those of other extracts. ABTS radical scavenging ability were 94.61%, 95.85%, 94.36%, and 96.69%, respectively. SOD (superoxide dismutase)-like activities were in the order EFCT (32.60%) > EFCTS (27.10%) > EFCT (23.30%) > ECT (22.00%), and nitrite scavenging activity was in order of EFCTS (51.18%) > EFCTL (45.61%) > EFCT (41.93%) > ECT (27.76%), respectively. Ferrous ion chelating activity of EFCTL (67.34%) and EFCTS (60.36%) was significantly the highest, whereas ECT (52.34%) and EFCT (51.73%) had not different significantly. Xanthine oxidase, elastase and tyrosinase inhibitory activities at 0.5% (w/v) solutions of EFCTL and EFCTS were somewhat higher than those of non-fermented ECT. In conclusion, we provide experimental evidence that extracts of fermented cudrania tricuspidata of B. subtilis and B. licheniformis exhibited higher antioxidant activities and inhibitory actions on elastase and tyrosinase compared with non fermented cudrania tricuspidata.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.834-844
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• 2014

Postharvest browning of mushroom (Agaricus bisporus) reduces the shelf life of harvested mushrooms. Here, mushrooms were dipped in various solutions (distilled water; DW, 0.25% rice bran extract; RB, 0.1% ascorbic acid; AA, RB + AA) for 3 min. After air-drying at room temperature, the dipped mushrooms were packaged in a polypropylene (PP) films and stored at 4 or $15^{\circ}C$. The quality changes of mushrooms were measured in terms of color, gas composition, firmness, and sensory evaluation during storage. Rice bran extract was measured for total polyphenol content, total flavonoid content, DPPH, ABTS radical scavenging, chelating activity and PPO inhibition activity. No difference in firmness were found in the mushroom samples regardless of dipping solution or storage temperature. At both 4 and $15^{\circ}C$ storage temperatures, RB + AA solution-dipped samples showed the highest L value and lowest delta E value. During the storage period, sensory evaluation showed that overall acceptability of mushrooms treated with RB and RB + AA solution was higher than that of the untreated mushrooms. Total polyphenol and flavonoid contents of 0.25% rice bran extract were $36.42mg\;GAE{\cdot}g^{-1}$ and $4.85mg\;QE{\cdot}g^{-1}$, respectively. The DPPH and ABTS radical scavenging activity of 0.1% ascorbic acid was higher than that of 0.25% rice bran extract. The highest copper ($Cu^{2+}$) chelating activity was found in the 0.25% rice bran extract. The PPO inhibition activity of 0.1% ascorbic acid was higher than that of 0.25% rice bran extract. Our results suggest that 0.25% rice bran extract with 0.1% ascorbic acid is effective anti-browning agent for maintaining quality of Agaricus bisporus during storage.