• Korean Journal of Pharmacognosy
• /
• v.29 no.1
• /
• pp.28-34
• /
• 1998

It has been known that diseases related with aging or cancer result, at least in part, from free radicals, and antioxidants may reduce or prevent the abnormalities associated with free radical formation via its scavenging action. Thus, this study was carried out to investigate the antioxidative and antimicrobial activities of nut species for the purpose of developing antioxidant from natural products. Antioxidant activities of four kinds of nuts such as chestnut, groundnut, walnut and acorn were examined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. The extracts from chestnut hull and acorn barnyard millet showed strong antioxidative activities among 10 samples tested. Because of their highest antioxidative activity among 10 samples, radical scavenging effects of 4 different extract compartments (Hexane, EtOAc, BuOH and $H_2O$ extracts) from chestnut hull and acorn barnyard millet, were further examined by DPPH method. EtOAc and BuOH extracts exhibited antioxidative activities similar to those of natural, tocopherol or synthetic antioxidants, BHA. These findings demonstrates that major fraction of the antioxidative activity of chestnut hull or acorn barnyard millet was the EtOAc and BuOH extract compartments. However, antimicrobial activities against food-related bacteria and yeasts was relatively weak.

• Nutritional Sciences
• /
• v.3 no.1
• /
• pp.36-41
• /
• 2000

The aim of this study was to evalute the effect of multivitamin-mineral supplementation during pregnancy on plasma levels of antioxidants, erythrocyte antioxidant enzyme activities, and lipid peroxidation. A controlled, semi-randomized, prospective trial was performed by comparing the supplement group, which received multivitamin-mineral tables once daily for 10 weeks, with the control group. Plasma levels of $\beta$-carotene, tocopherol, coenzyme Q10, ascorbate, folate, zinc, and selenium and malondialdehyde (MDA), as well as the activities of superocxide dismutase(SOD) and glutathione peroxidase(GSH-Px) in erythrocytes were measured initially (20 wk gestation) and at the end of the intervention (34 wk gestation). In the control group, plasma ascorbate and selenium levels decreased and tocopherol levels increased. In the supplement group, a significant increase in plasma $\beta$-carotene(46%), conenzyme Q10 (42%), and zinc (24%) was observed after 10 weeks of supplementation. No changes were observed in the plasma levels of MDA, and erythrocyte GSH-Px activity, while SOD activity increased in both control group and the supplement group during the intervention. These data suggest that multivitamin-mineral supplementation during pregnancy produced moderate increases in plasma $\beta$-carotens, coenzyme Q10, and zinc concentrations but the enhancement of those plasma antioxidants had on direct on the plasma level of MDA, erythrocytes SOD or GSH-Px activities.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.4
• /
• pp.538-547
• /
• 2019

The aim of the present study was to evaluate the effects of two well-known natural antioxidants, vitamin C (VC) and vitamin E (VE), on the antifungal activity of honokiol against Candida albicans. The broth microdilution method was employed to test the antifungal activities of honokiol with or without antioxidants in the medium against C. albicans strain. Intracellular reactive oxygen species and lipid peroxidation were determined by fluorescence staining assay. Mitochondrial dysfunction was assessed by detecting the mitochondrial DNA and the mitochondrial membrane potential. We observed that VC could significantly potentiate the antifungal activities of honokiol while VE reduced the effectiveness of honokiol against C. albicans. In addition, VC accelerated honokiol-induced mitochondrial dysfunction and inhibited glycolysis leading to a decrease in cellular ATP. However, VE could protect against mitochondrial membrane lipid peroxidation and rescue mitochondrial function after honokiol treatment. Our research provides new insight into the understanding of the action mechanism of honokiol and VC combination against C. albicans.

• Journal of the Korean Society of Food Culture
• /
• v.27 no.6
• /
• pp.719-729
• /
• 2012

We sought to study the qualities and scientific benefits of Dongchimi, a traditional Korean food. We compared and analyzed ingredients used for the appearance and storability of dongchimi - honggot (Brassica juncea czerniak et coss), cockscomb (Celosia cristata L.), and beet Beta vulgaris L.). We specifically examined the antioxidative and antibacterial activity of pigments from extracts of these ingredients. Distilled water ($H_2O$) and 1% citric acid were used to safely extract pigments. The antioxidative activity of the pigments was then measured for total phenolic compounds, SOD (Super Oxide Dismutase), and EDA (Electron Donation Ability) by DPPH. The antibacterial activity of was also assessed by a Paper disc solution. Our results show that the pigments had sufficient antioxidative activity and had antibacterial properties against Gram positive and negative bacteria. In particular, Cockscomb (used for enhancing color) contained the highest amount of polyphenol compounds and had the most efficient antioxidative activity.

• KSBB Journal
• /
• v.26 no.6
• /
• pp.565-568
• /
• 2011

In this study, it was investigated the antioxidant activity of laminarin degraded by gamma irradiation. Because the activities of antioxidants have been attributed to various mechanisms, different assay methods have been conducted and compared. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power, and lipid peroxidation inhibitory activity of degraded laminarin were measured and compared with non-degraded. All of these results showed that the antioxidant activity of laminarin degraded by irradiation was increased depending on the absorbed dose. Therefore, gamma irradiation could be an alternative method for the preparation of degraded laminarin with higher antioxidant activity.

• Journal of the Korean Chemical Society
• /
• v.56 no.4
• /
• pp.464-467
• /
• 2012

A novel chitosan derivative with double quaternary ammonium salt-2-pyridine-acetyl-N-trimethyl chitosan chloride (PATMCS) was synthesized and the antioxidant activity of PATMCS against hydroxyl radicals was assessed. The results indicated that PATMCS had potent hydroxyl scavenging activity. The $IC_{50}$ of PATMCS was 0.13 mg/mL. PATMCS showed 100% scavenging effect at a dose of 0.8 mg/mL which markedly better than that of N-trimethyl chitosan chloride (TMCS). It was confirmed that quaternary chitosan derivatives showed potent antioxidant activity. PATMCS has double quaternary ammonium salt structure in the molecules. Therefore, the antioxidant activity of PATMCS was better than TMCS. The above results are theoretically fundamental for further development and making use of chitosan resources to prepare new antioxidants.

• Nutrition Research and Practice
• /
• v.1 no.3
• /
• pp.189-194
• /
• 2007

This study investigated in vitro antioxidant activity of Sonchus oleraceus L. by extraction solvent, which were examined by reducing power, hydroxyl radical-scavenging activity(HRSA) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays. 70% MeOH extract had the greatest reducing power while EtOH extract had the greatest HRSA. The antioxidant activity of S. oleraceus extracts was concentration dependent and its $IC_{50}$ values ranged from 47.1 to $210.5\;{\mu}g/ml$ and $IC_{50}$ of 70% MeOH, boiling water and 70% EtOH extracts were 47.1, 52.7 and $56.5\;{\mu}g/ml$, respectively. 70% MeOH extract of S. oleraceus contained the greatest amount of both phenolic and flavonoid contents. The extracts tested had greater nitrite scavenging effects at lower pH conditions. The cytotoxic activity showed that EtOH extract had the best activity against the growth of stomach cancer cell. These results suggest that S. oleraceus extract could be used as a potential source of natural antioxidants.

• Journal of the Korean Society of Food Culture
• /
• v.22 no.3
• /
• pp.336-341
• /
• 2007

Antioxidant activity of Astragalus membranaceus, Polygonatum stenophyllum, Angelica gigas, Acanthopanax sessiliflorus and Angelica pubescens extracts cultivated in Jecheon prepared with different solvents were determined by 1,1-diphenyl-2-picrylhydrzyl(DPPH) radical scarvenging ability and thiocyanate method . The highest hydroxy radical scarvenging activity was shown in Acanthopanax sessiliflorus, while the lowest was in Polygonatum stenophyllum. Angelica gigas showed strong antioxidant activity by thiocyanate method. Methanol extracts and water extracts showed higher antioxidant activities than ethanol extracts. Angelica pubescens showed the highest polyphenol contents and Acanthopanax sessiliflorus showed the highest flavonoid contents. Direct correlation between the hydroxy radical scavenging activity and polyphenol contents or flavonoid contents was established by simple regression(r>0.8) in each solvent extracts. Among medicinal plants cultivated in Jecheon, Acanthopanax sessiliflorus and Angelica pubescens showed strong antioxidant activities. These results suggest that methanol or water extracts of several medicinal plant cultivated in Jecheon could be used as natural antioxidants.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.442-444
• /
• 2002

Seedlings of spinach (Spinacia oleracea L. "King of Denmark" and "Minsterland") were grown with or without supplemental UV-B under field conditions for five or nine days when their fifth or sixth leaves were expanding. Except two leaves which were just expanded and expanding, all other leaves of each seedling were removed before tested. One of these two leaves was exposed to UV-B irradiation and the other leaf was covered with lumiror film (no transmission below 320 nm) to prevent it from UV-B exposure. l,l-diphenyl-2-picrylhydrazyl scavenging activities (antioxidative activity) in leaves without covers were increased according to UV-B doses they were exposed to. And removal of UV-B exposure with lumiror decreased foliage antioxidative activities. This increase or decrease of activities in leaves did not dependent on the UV-B doses their paired leaves were exposed to in both two cultivars. The results demonstrated that spinach foliage antioxidants induced by UV-B exposure were not transported into another leaf.

• YAKHAK HOEJI
• /
• v.50 no.5
• /
• pp.322-325
• /
• 2006

In the course of developing novel antioxidants, we synthesized four of 6-hydroxy-7-methoxy-4-oxochroman-2carboxylic acid dialkylamides (3a-d) $(13{\sim}18%)$ and four of 6-hydroxy-7-methoxychroman-2-carboxylic acid dialkylamides (4a-d) $(52{\sim}89%)$, incorporating the basic amine functionality. None of these compounds exhibited significant antioxidant activity possibly due to the hydrophilic character of the basic amine side chains.