• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.523-532
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• 2014

This study was done to evaluate the antioxidant effect of oak hot water extracts on the oxidative stress induced by reactive oxygen species (ROS). The cytotoxicity of $H_2O_2$-induced oxidative stress was performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for the cell viability according to the dose-dependent treatment. Oak extracts demonstrated a dose-dependent ability to inhibit $H_2O_2$-induced apoptosis in cultured tenofibroblasts, as assessed by MTT assay and FACS analysis. $H_2O_2$ increased the phosphorylation of extracellular regulated kinase1/2 (ERK1/2) and of c-Jun N-terminal kinase (JNK) and the production of reactive oxygen species (ROS). In contrast, treatment with oak extracts was decreased this activation of ERK1/2 and JNK, as confirmed by western blot analysis, and reduced the production of ROS, as verified by fluorescent microscopic and flow cytometry (FACS) analyses. These findings suggest that oak extracts, by suppressing JNK, ERK1/2, and intracellular ROS production, have a concentration-dependent antiapoptotic effect on achilles tenofibroblasts exposed to an oxidative stressor, and may have therapeutic potential.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.475-481
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• 2005

In an effort to identify a new environment-friendly algicide, we examined the ability of extracts from the leaves and stems of nine Korean oak tree species to inhibit growth of the bloom-forming cyanobacterium, Microcystis aeruginosa. At a concentration of 100 mg $L^{-1}$, five of the oak tree extracts (QAT-L, QAT-5, QAS- L, QGI-5, and QSA- L) decreased the cell density of M. aeruginosa by over 90% for 7 days. At a concentration of 20 mg $L^{-1}$, the same five extracts inhibited the growth of M. aeruginosa by approximately 50%. The minimum concentration of oak tree extracts required for effective inhibition of M. aeruginosa (20 mg $L^{-1}$) is comparable to that of the known algicide, tannic acid (17 mg $L^{-1}$), which is thought to be one of the main active ingredients in the oak tree extract. These findings suggest that oak extracts may be useful as an environment-friendly algicide to control the bloomforming cyanobacterium, M. aeruginosa, in eutrophic waters.

• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.833-837
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• 2005

Antioxidative activities of pine, oak, and lily pollen extracts were evaluated based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability and inhibition of lipid peroxidation in animal tissues. Each pollen was extracted with 50% ethanol, 100% ethanol or water. DPPH radical-scavenging capacity of 50% ethanol extract ($EC_{50}$ 40.0 mg/mL) of pine pollen was higher than those of water (46.8 mg/mL) and 100% ethanol (131.2 mg/mL) extracts of pollen. Fifty percent ethanol (3,2 mg/mL) was also better than 100% ethanol (4.5 mg/mL) and water (8.3 mg/mL) for extraction of oak pollen. For preparation of lily pollen extracts, 100% ethanol was most effective (14.0 mg/mL), followed by water (18.8 mg/mL) and 50% ethanol (24.0 mg/mL). Oak pollen showed higher DPPH radical-scavenging activity than others. Lipid peroxidation in rat brain homogenate induced by ascorbate-Fe3+-EDTA and rat kidney homogenate were inhibited by water extracts of all pollens in dose-dependent manner. Extracts of oak and lily pollen showed higher lipid peroxidation inhibition than pine pollen extract. Polyphenol content was highest in oak pollen extract $(32.5{\pm}0.7\;{\mu}g/mg\;pollen)$, followed by lily extract $(25.9{\pm}1.4\;{\mu}g/mg\;pollen)$ and pine extract $(9.3{\pm}0.7\;{\mu}g/mg\;pollen)$.

• Natural Product Sciences
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• v.29 no.1
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• pp.42-49
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• 2023

This study investigated the effect of ethanol extracts of horsetail, alfalfa, ortie, chêne and aleppo oak on blood coagulation in vitro. Extraction was performed by the maceration method. Extracts were mixed with platelet and plasma, then prothrombin time (PT), activated partial thromboplastin time (APTT) and platelet aggregation tests were conducted. Alfalfa extract had a dose-dependent effect on the PT. Ortie, and horsetail, reduced the PT significantly compared to control group. Alfalfa, horsetail, and ortie reduced the APTT, but their effect was insignificant compared to the control group. The pooled extract showed the highest effect compared to the single extracts in a dose-dependent manner. Horsetail and alfalfa induced platelet aggregation in response to arachidonic acid but not in response to collagen. In the case of ortie, no aggregation occurred regarding the arachidonic acid, and incomplete was observed in response to collagen. Interestingly, blood clotting occurred immediately after adding the chêne, aleppo oak and the pooled extract, and therefore platelet poor plasma (PPP) and platelet rich plasma (PRP) became jelly. Generally, chêne and aleppo oak, as well as pooled extract, were more effective in inducing both primary and secondary coagulation pathways via shortening the PT and APTT, and induction of platelet aggregation.

• 보존과학연구
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• s.30
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• pp.157-170
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• 2009

We have evaluated the antifungal activities of oak vinegar to develop a natural biocide for organic cultural heritage. Fungi used in this study were screened from the cultural heritages, Kyujanggak and JanggyeongPanjeon and tested on organic substrates-degrading ability. In the results, 7 species of fungi have produced the extracellular enzymes to degrade CMC, xylan, lignin. Thus, we have used these seven species fungi to investigate the antifungal activity of oak vinegar in this study. In the result, the antifungal activity of oak vinegar indicated positive potencial. Especially, methylene chloride and ethylacetate fractions of the oak vinegar had high activities at the concentration of 5.0mg/disc. In these fractions, many different kinds of compounds such as phenolic and furfural, etc. were analyzed by GC-MS. The experiments indicated that the development of a biocide using natural extracts can have a potential to conserve of organic cultural heritages.

• Food Science and Preservation
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• v.18 no.1
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• pp.72-78
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• 2011

The physiological properties of oak mistletoe slice extracts were investigated. The total polyphenol content of mistletoe extracts was 50.28-109-69 mg%, depending on extraction conditions. The polyphenol content increased as extract concentration rose (25 mL/g>50 mL/g>100 mL/g). The electron-donating ability (EDA) of the 60% (v/v) ethanolic extract was 68.88% at 25 mL/g; this was the highest value of all extracts tested (p<0.05). The SOD-like activities of water, 30%, 60%, and 90% (all v/v) ethanolic extracts were 15.24-30.84% lower than those of 1.0% and 0.1% (both w/v) L-ascorbate solutions. Tyrosinase inhibitory activities of all samples were 3.40-30.92% lower than those of 1.0% and 0.1% (both w/v) L-ascorbate solutions. Nitrite-scavenging abilities measured at pH 1.2 and pH 3.0 were highest when the water, and the 30%, 60% and 90% (all v/v) ethanolic extracts, were tested. The results expand our understanding of the physiological properties of oak mistletoe slice extracts.

• Korean Journal of Veterinary Research
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• v.45 no.2
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• pp.151-154
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• 2005

The purpose of this study is to examine the elemental compositions, antioxidant and antitumor activity of water, 20%, 40%, 60%, and 80% ethanol extracts obtained from the fruiting body of Phellinus gilvus. In electron donating ability test, the strong activities more than 70% were observed in $80{\mu}g/ml$ of 20%, 40%, 60% and 80% ethanol extracts from the fruiting body of P. gilvus grown in oak and sawdust. The antitumor activity was evaluated by sulforhodamine B (SRB) in terms of cell survival level. The tumor cells (sarcoma 180) were treated with various ethanol extracts (water, 20, 40, 60 and 80%). The results showed that all extracts inhibited proliferation showing a dose-dependent manner against tumor cells.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.396-402
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• 2004

For industrial application to manufacturing functional foods for health using browned oak mushroom, we examined its reducing power, inhibitory effect on intracellular reactive oxygen species, phenolic compounds and phytates contents, modulatory effects on NO radical and matrix metalloproteinase 9 (MMP9) generation by activated macrophages, and antimutagenicity in order to evaluate the functionality of browned oak mushroom for health. While overall ethanolic extracts have higher reducing power than aqueous extracts, browning reaction was found to increase reducing power by up to 28% at a 3.32 mg/ml sample concentration. Browning reaction also increased phenolic compound content by about 73% compared to raw mushroom. However, any significant change in phytate content could not be detected. At a concentration of $100\;{\mu}g/ml$, treatment of ethanolic extract of oak mushroom increased NO generation over 43% in LPS-stimulated macrophage. On the contrary, the aqueous extracts rather decreased it over 17% at the same sample dose. However, any solvent extract from browned oak mushroom seems not to cause any change in both NO production and MMP9 activity. In addition, browning reaction did not allow any significant change in suppressive effect on mitomycin C-induced mutagenesis as examined with SOS chromotest. These results suggest a possible use of browned oak mushroom with unmarketable quality as a material for development of a variety of processed functional foods for health.

• Food Science of Animal Resources
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• v.18 no.1
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• pp.42-49
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• 1998

The contents of holocellulose, one of the main components of the wood, were 83.9% in oak wood and 76.9% in apple wood, respectively. Those of hemicellulose were 16.41 and 20.33%, and in lignin 23.0 and 19.7%, respectively. Six species of domestic oak wood and apple wood were considered to be suitable for smoking materials due to the low content of lignin. Benzo(a)pyrene contents in smoke flavoring prepared with oak wood at 150, 400 and 500$^{\circ}C$ were 0. 4, 3. 7 and 5.6$\mu\textrm{g}$,/kg, respectively. The amounts of phenanthrene were 112.7, 131.4 and 255.9$\mu\textrm{g}$/kg, respectively, in each temperature. The amounts of polycyclic aromatic hydrocarbons(PAH) in smoke flavory were in the order of phenanthrene＞anthracene＞pyrene＞benzo(a)anthracene＞chrysene＞benzo(b)fluoranthens＞benzo(a)pyrene Benzo(a)pyrene contents in smoking extracts prepared with apple wood at 150, 400 and 500$^{\circ}C$ were 0.4, 3.3 and 5.5$\mu\textrm{g}$/kg, respectively. Phenanthrene contents in those samples were 72.7, 100.2 and 220.5$\mu\textrm{g}$/kg, respectively. Contents of each PAH showed the same order as in oak wood.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.178-188
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• 2018

The aim of this study was to assess the in vitro potential of water extract from torrefied oak wood as a natural antioxidant. The antioxidant potential of the extracts was assessed by employing different in vitro assays, including reducing power, DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)], and FRAP (ferric reducing antioxidant potential) assays. The DPPH activity of the extract was increased in a dose-dependent manner. Measurement of total flavonoid content of water extract from torrefied oak wood was achieved using an aluminum chloride colorimetric assay; the extract contained 192.12 mg/g flavonoid, which was significantly high when compared with standard quercetin. The results obtained in this study indicate that water extract from torrefied oak wood has significant potential for use as a natural antioxidant agent.