• Environmental Analysis Health and Toxicology
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• v.13 no.3_4
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• pp.105-115
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• 1998

Reactive oxygen species (ROS) are highly reactive molecules due to their unpaired electron. They have been suspected as one of the major tissue damage inducers in biological metabolic systems. Antioxidant enzymes, such as catalase and superoxide dismutase, could not repair all the oxidative damages resulting from those excessive toxic ROS. It is, therefore, urgent to develop effective antioxidants to relieve from the oxidatire damages. In this study antioxidative effects were investigated by using two flavonoids such as quercetin and naringenin and a flavonoid-rich extract, Ginkgo biloba extract in combination with paraquat that is known as a strong generator of oxygen radicals. The results are summeringed as follows: 1. To assess radical scavenging ability reduction concentrations (IC$_{50}$) of 1,1-diphenyl-2-picrylhydrazine (DPPH) within 15 minutes were measured. The values of the IC$_{50}$ of quercetin and Ginkgo biloba extract were 15.4 $\mu$M and 13.2$\mu$g/ml, respectively. Their radical removing activities showed concentration-dependent manners. 2. In the hydrogen peroxide assay by using PMS-NADH system, quercetin, naringenin and Ginkgo biloba extract led to removing hydrogen peroxide in concentrationdependent manner whose removing abilities at 100$\mu$M or 100 $\mu$g/ml were 75.6, 25.8 and 26.0%, respectively. 3. In the hydrogen peroxide-induced rat blood hemolysis assay all three compounds led to similar effects whose hemolysis inhibition ratios at 100$\mu$M or 100$\mu$g/ml were 68.0, 5.14 and 55.8%, respectively. 4. In the xanthinee oxidase assay by measuring degree of NADH oxidation in the presence of hypoxanthine and xanthinee oxidase, both quercetin and Ginkgo biloba extract showed excellent activities showing 42.8 and 24.2% inhibiting xanthine oxidase activity at 100$\mu$M or 100$\mu$g/ml concentrations, respectively.

• Journal of Periodontal and Implant Science
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• v.26 no.2
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• pp.542-556
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• 1996

Previous studies have shown that Magnoliae cortex and Ginkgo biloba extracts were showed on the antimicrobial and anti-inflammatory action, in vitro. The purpose of this study was to evaluate on the effect of antimicrobial and anti-inflammatory activity of Magnoliae cortex and Ginkgo biloba extracts containing dentifrice in gingivitis. 70 subjects with gingivitis were divided into an experimental group which performed normal oral hygiene procedure with Magnoliae cortex and Ginkgo biloba extracts containing dentifrice and a control group which also performed normal oral hygiene procedure with the same dentifrice without the natural extracts and completed a doubleblind, cross-over study. At baseline and 3 weeks, subjects were assayed for clinical study by plaque index, gingival index, pocket depth, GCF rate, and microbiological study by subgingival dental plaque bacterial morphotypes by phase contrast microscopy, total anaerobes, total aerobes, Black pigmented bacteroides, A.actionomycetemcomitans, A.viscosus, C.rectus, Ssenguis; P.gingivalis, P.intennedia by bacterial culture and immunofluorescence microscopy. After 3 weeks using their respective dentifrices, reductions in the clinical indices of subjects were similar between the experimental dentifrice group and a control dentifrice group except for statistically significant much reductions in PI, GI, and GCF rate in the experimental dentifrice group as compared to control dentifrice group. Also statistically significant reductions in the motile rods and Spirochetes were found in both experimental group to compare with control group, however statistically much reduction in total anaerobes, Black pigmented bacteroides, and P.gingivalis, P.intennedia were found in the experimental dentifrice group as compared to control dentifrice group. This results indicates that Magnoliae cortex and Ginkgo biloba extracts containing dentifrice might be useful for elimination of gingival inflammation.

• Toxicological Research
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• v.12 no.1
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• pp.129-136
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• 1996

A fertility and general reproductive a. bility study was performed in Sparque-Dawley rats intravenously injected with Ginkgo biloba extract (EGb 761), a potential pharmaceutical excipient, at dose levels of 7.5, 15, and 30 mg/kg/day. Male rats were treated with Ginkgo biloba extract (EGb 761)from 14 days before mating until 21 days after delivery. Female rats received extract for 2 months prior to mating. No abnormal signs were noted in mating or fertility of the rats treated with Ginkgo biloba extract (EGb 761). No significant external, visceral, and skeletal anomalies or mental and physical development attributable to treatment was noted in any fetuses examined. The fertility of F1 generation was not affected by the treatment also. It was concluded that Ginkgo biloba extract (EGb 761) has no harmful effect on mating, fertilization, implantation, embryonic development and normal physical development.

• Journal of the Korean Applied Science and Technology
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• v.38 no.5
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• pp.1229-1240
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• 2021

Ginkgo (Ginkgo biloba L.) seeds, called 'Baekqwa', were extracted from 70% ethanol to investigate the whitening effect and to confirm the application potential as a cosmetic material. Ginkgo seed ethanol extracts (GBE) were treated with B16F10 melanoma cells, and melanin contents and tyrosinase, which is the main enzyme concerning the synthesis process of melanin, inhibitory activity were confirmed. As a result, there were inhibited in a concentration-dependent manner, and GBE also significantly reduced the protein expression and mRNA levels of tyrosinase, tyrosinase-related protein-1, -2 (TRP-1, -2), and their upstream transcription factor, microphthalmia-associated transcription factor (MITF). These results suggest that GBE could be used as an effective whitening agent that has an inhibitory effect on melanin production by regulating the expression and degradation of MITF in melanocytes.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.408-416
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• 2017

This study describes DNA fingerprinting analysis of twenty-three natural monument individuals of Ginkgo biloba using eight microsatellite markers. The average number of observed alleles was 6.875, and the expected heterozygosity and the observed heterozygosity were 0.711 and 0.710, respectively. This results were similar to those of the previous studies on Ginkgo trees analyzed by same markers in China and Japan. PIC value and PD were calculated at 0.677 and 0.9999 respectively, indicating a high individual identification efficiency. In fact, all of the natural monument ginkgo trees and additionally analyzed thirteen general ginkgo tress were identified by genotype comparison. PI and PD calculated in three markers (Ging06, Gb60, Gb61) with the highest PIC values calculated in natural monument ginkgo trees were $8.045{\times}10^{-5}$ and 99.99%, respectively. Thus, these three markers could be preferentially used in DNA fingerprinting for identifying ginkgo tree individuals. The results in this study will be useful for management of natural monument ginkgo trees, proliferation of their progeny and genetic identification of individuals selected in breeding process.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.4
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• pp.377-383
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• 1997

Studies were conducted on the nature of allelopathic effect of the substances in the waste of ginkgo leaves from pharmaceutic factory. In the first step, to find out whether there was any allelophatic effect, young seedlings of radish and rice were grown in the water (crude) extract of ginkgo leaf waste and in different liquid/lquid partitioned fractions of EtOAc at pH 9, EtOAc at pH 3, and BuOH. As second step, attempts were made to isolate and identify the allelophatic substance in different liquid/liquid partitioned fractions using GC/MS and NMR techniques. The water (crude) extract of ginkgo leaf waste retarded the growth of radish seedlings under 10% concentration. In case of rice seedlings, the water extract of ginkgo leaf extract showed adverse effect on the growth when combined with $3.3{\times}10^{-6}M$ gibberellin A3. All of the liquid/liquid fractions of crude extract showed strong retardation of seedling growth of radish and rice at the concentration of 1%. Allelophatic substance was isolated from the crude extract using liquid/liquid partition, column chromatography and HPLC techniques. The analytical results of isolated componet using GC/MS and NMR proved that the allelophatic substance in the ginkgo leaf wastes is catechol; one of phenol compounds. Based on the experiences current study, a practical method for the testing of allelophatic effect of crude extract of some materials was proposed. In this method, rice seeds were allowed to sprout until the length of coleoptile to reach 0.5 mm. Such seedlings were submerged in the solution containing supposedly allelophatic substance and the length of shoot and root was measured 3 days after treatment.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.393-398
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• 2003

Effects of convection oven dehydration conditions on the physicochemical and sensory properties of ginkgo nut powder were examined using three types of pre-treatment on ginkgo nuts: coarse grinding of ginkgo nut (GR); coarse grinding followed by 1 min blanching (GB); 3 min blanching followed by coarse grinding (BG). Pretreated ginkgo nuts were dried in convection oven at 70 and $80^{\circ}C$ to the moisture content of approximately 5%. Rehydration rate, swelling power, solubility, lightness, and greenness of GB ginkgo nut powder dried at $70^{\circ}C$ were the most similar to those of freeze dried one. GR and GB samples dried at $70^{\circ}C$ had higher sensory values of green color and ginkgo nut flavor. Ginkgo nut powder with desirable quality attributes could be produced by drying GB in convection oven at $70^{\circ}C$ for 10 hr.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2843-2846
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• 2014

• Journal of Environmental Health Sciences
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• v.27 no.1
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• pp.124-130
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• 2001

Ginkgo biliba has been used for bronchitis and asthma in oriental countries and its leaf extract(GBE) contains 24% ginkgoflavone glycoside and 6% terpenoid. Flavonoids and terpenoids are known to have various antioxidant effects such as scavenging of free radicals and chelation of transtional metals. Antioxidant effect of GBE against 1,2,4-benzenetriol(BT), one of toxic metabolites of benzene, was demonstrated throughbsister chromatid exchange(SCE) analysis, single cell gel electrophoresis(SCGE) analysis, DNA cleavage assay and lipid peroxidation production analysis. The means of SCE frequencies at 10, 25 and 50$\mu$M concentration of BT were 7.72, 8.02, 9.22 respectively. In addition of GBE with concentration of 50, 200 and 500$\mu\textrm{g}$/$m\ell$, SCE frequencies were decreased significantly.(p<0.05) According to SCGE analysis, BT induced DNA damage in a dose-dependent manner at concentration of 10 and 50 $\mu$m and the DNA damage induced by BT was significantly protected by GBE(p<0.001). No genotoxicity was observed by GBE treatment alone on DNA cleavage. The effect of BT on lipid peroxidation product, Malondiadehyde(MDA), was increased with concentration of BT(10 and 50 $\mu$M) and reduction in MDA was noted when GBE was added. From above results it is suggested that GBE could protect the cell and DNA from pro-oxidant effect by reactive oxigen species induced by BT.

• The Plant Pathology Journal
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• v.31 no.1
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• pp.61-66
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• 2015

From study of antifungal actions on the rice sheath blight by using the extract of Ginkgo biloba outer seedcoats, we found that the extracts of Ginkgo biloba outer seedcoats of all treatment concentrations had inhibited the rice sheath blight. Among them, the most effective concentration was 250 mg/l at which the growth of microbe was 26 mm and even at the packaging test, when sprayed the G. biloba outer seedcoats at the level of 250 mg/l, the damage rate of the rice sheath blight was identified as 13%. As a result investigating the antifungal activity by separating polysaccharides from G. biloba outer seedcoats, it showed that the clear zone of 14 mm or more was formed at the concentration of 250 mg/l or higher. Based on these results, we concluded that the G. biloba outer seedcoat is a natural substance with the antifungal activity on the rice sheath blight.