• Toxicological Research
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• v.16 no.4
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• pp.293-301
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• 2000

Toxicity of a combined preparation of ticlopidine and ginkgo biloba extract (EGb 761) in a ratio of 10: 4 was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance intragastrically at a dose of 0 mg/kg, 17 mg/kg, 52 mg/kg or 156 mg/kg for 91 consecutive days. No death or abnormal clinical sign was observed throughout the administration period. There was no difference in body weight gain, food intake or water consumption among different dose groups. Test sub-stance-related differences were not observed in urinalysis. In hematological results mean corpuscular hemoglobin (MCH) of low and high dose male group was increased. Prothrombin time of medium and high dose female group was decreased. A significant increase in serum total cholesterol was observed in both sexes of rats treated with a daily dose of 156 mg/kg, but all the other values obtained in serum chemistry appeared to be within normal ranges. A dose dependent increase in the relative liver and kidney weights was observed in both male and female rats. There were no gross pathological findings at terminal sacrifice. Microscopic histopathological examination did not show any lesion associated with administration of the test substance. The results suggest that under the conditions employed in this study no observable effect level (NOEL) of the test substance be greater than 17 mg/kg/day, but less than 52 mg/kg/day.

• The Korea Journal of Herbology
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• v.20 no.4
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• pp.11-16
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• 2005

Objectives : This study was designed to propose the effective herb-processing method of Ginkgo Folium in the Oriental medicine. Methods : The books, papers and patents were used to examine the recent usage of Ginkgo Folium. Results : The toxic ingredients of Ginkgo Folium should be removed. Accordingly, a detoxification process using a nonpolar solvent and a vinegar-roasting process in sequence are desirable to assure its safety. The previously developed standard extract (e.g. EGb 761) could be used as a powdered Oriental medicine as well. Conclusions : Ginkgo Folium could not be used widely to treat the diseases in ancient Oriental medicine, because the toxic ingredients could not be removed by any method until recent year. However, Ginkgo Folium might be used as a herbal medicine that invigorates the blood without any difficulty using herb-processing methods suggested in this paper.

• Korean Journal of Organic Agriculture
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• v.29 no.1
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• pp.97-109
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• 2021

Plant parasitic nematodes are causing significant damage in crop production. There is a need to develop eco-friendly nematicide that reduces the damage of nematode and has little effect on the environment and human. In this study, we have isolated a substance having nematicidal activity from Ginkgo biloba L. outer seedcoat. Studies of G. biloba L. outer seedcoat are insufficient compared to the seed and leaves due to their odor and toxicity. The dried G. biloba L. outer seedcoat was extracted with dichloromethane:methanol (1:1) and fractionated into hexane, ethyl acetate and H₂O. Four steps TLC were performed from EtOAc fraction to purely isolate GB4-3 with nematicidal activity. To compare nematicidal activity, G. biloba L. seedcoat methanol extract and purified GB4-3 were investigated in terms of treatment concentration and time. As a result, the nematicidal activity increased with concentration and time. In the place treated with 20 ㎍/mL of crude G. biloba L. seedcoat MeOH extract, strong activity appeared after 12 hours, and 46% nematicidal activity shown after 18 hours. About 69% of nematicidal activity was confirmed in the place where GB4-3 purified from outer seedcoat was treated with 20 ㎍/mL, and the possibility of development as nematicide was very high. This study could be used as a basic data for the development of a nematode preparation from G. biloba L. outer seedcoat.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.324-328
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• 1998

We screened the methanol extracts from 133 plant species growing in Korea for antimicrobial activity against enterohemorrhagic Escherichia coli 0157 : H7. Those are selected from three plant grouping ; traditional medicinal herbs, edible plants, and flowers. They were tested by disk diffusion assay. From evaluation of the inhibition zone diameter of microbial growth, we found that the flower extract of Rhododendron Schilpenbachii Max had the most significant antimicrobial activity against this bacteria. Extracts from most of the vegetables and plants did not show antimicrobial activity except for the leaves of Ginkgo biloba L. and seeds of Prunus Dallicina L. did not show antimicrobial activity except for the leaves of Ginkgo biloba L. and the seeds of Prunus sallicina L.

• Korean Journal of Pharmacognosy
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• v.30 no.3
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• pp.306-313
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• 1999

Polyphenol Oxidase(PPO) was purified from an extract of Ginkgo biloba leaves by ammonium sulfate fractionation followed by sephadex G-150 column chromatography, which resulted in a 18-fold increase in specific activity. The enzyme was most active at pH 8.5 and the temperature optimum for the PPO catechol oxidation reaction was $45^{\circ}C$. Heat inactivation studies showed that heating for 7, 9 and 48 min, at 80, 70 and $60^{\circ}C$ respectively caused a 50% loss in enzymatic activity and that the enzyme was completely inactivated after heat treatment at $90^{\circ}C$ for 60 min. Km values of the PPO for catechol, hydroquinone and 4-methylcatechol derived from Lineweaver-Burk plots were $6.06\;{\times}\;10^{-4}M,\;1.02\;{\times}\;10^{-3}M,\;1.41\;{\times}\;10^{-3}M$ respectively. Of the substrates tested, 4-methylcatechol was oxidized most readily and the enzyme did not oxidize monophenols. The enzyme datalyzed browning reaction was completely inhibited in the presence of reducing reagents, namely ascorbic acid, cysteine, glutathione, 2-mercaptoethanol, potassium metabisulfite at 0.5 mM level. Sodium chloride showed very little inhibition effect on Ginkgo biloba leaves PPO. Lineweaver-Burk analysis of inhibition data revealed that the inhibition by cysteine, 2-mercaptoethanol, potassium cyanide was competitive with ki values of $1.1\;{\times}\;10^{-5}M,\;2.4\;{\times}\;10^{-5}M,\;8\;{\times}\;10^{-5}M$, respectively. Among the divalent cations, $Cu^{2+}ion$ was a strong activator on PPO and $Mn^{2+}ion$ was little or no effect on PPO activity $Ni^{2+}ion$ was an inhibitor on PPO.

• 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.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2001.10b
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• pp.162-162
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• 2001

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.492-498
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• 2006

Ultraviolet(UV) radiation causes a variety of biological effects on the skin, including inflammation, pigmentation, photoaging and cancer. Free radicals are involved in inflammatory skin reactions induced by UVB radiation. In this study, we investigated the effects of antioxidants(Tea, Korean red ginseng, Ginkgo biloba extract) on UVB-induced skin damage. Tea, KRG and EGb 761 were topically treated to dorsal skin of ICR mouse. The mice were also treated soon after IMED ($1.4KJ/m^{2}$) of UVB irradiation. Skin pigmentation of irradiated mouse was observed by a chromameter after 2 weeks. Topical application of Tea, KRG and EGb 761 for 2 weeks decreased skin pigmentation compared to DVB control group(p<.05). Tea, KRG and EGb 761 also reduced UVB-induced infiltration of inflammatory cells. These results showed that Tea, KRG and EGb 761 as a topical application may have preventive effect against UVB-induced skin damage.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.11 no.1
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• pp.240-250
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• 1998

Background: Ginkgo biloba extract is used in disorser of cerebral and peripheral blood circulation, dysfunction of brain, atherosclerosis etc., but there are little study about GbE in oriental medicine. We wished to assessthe efficacy of GbE for the treatment of cerebral infarction Method : The study group comprised 40 patients who arrived at hospital during 48 hours after attack. All patient were devided into two group. The control group was treated with Uhuangcheongsimhuan, Seonghyangjeonggisan, acupuncture therapy only, while the GbE group was treated with above therapy plus 5 days of administration of GbE(40mg three times per day). Result: 1. Symptom improve scores did not showed significant difference between control and GbE group. 2. Vasoreactivity of carotid siphon increased significantly in GbE group after treatment (in the left only : p<0.05). 3. Vasorcactivity of radial artery increased significantly in GbE group after treatment(in the right only ; p<0.05). 4. PT, a-PTT, Fibrinogen did not showed significant changes between before and after treatment in both group. Conclusion: These findings suggest that vasoreactivity increasing effect of GbE may be useful in the prevention and treatment of cerebral infarction. But the vasoreactivity increasing effect of GbE may be different from symptom imroving.

• Toxicological Research
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• v.14 no.4
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• pp.547-555
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• 1998

The subchronic toxicity of a combined preparation of ticlopidine and ginkgo biloba extract (EGb 761) mixed in a ratio of 10: 4 was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance at a dose of 52 mg/kg, 156 mg/kg, or 467 mg/kg intragastrically for 30 consecutive days. Control rats were treated with vehicle only. Each group consisted of 10 rats. No death or abnormal clinical signs were observed throughout the administration period. A transient decrease in body weight gain and food intake was observed in the rats treated with the high dose (467 mg/kg), which was recovered to normal in a week. There were no drug-related differences in urinalysis and hematological results. A significant increase in serum total cholesterol and total protein was observed in both sexes of the rats treated with a dose of 467 mg/kg daily, but all the other values obtained in serum chemistry appeared to be within normal range. A dose dependent increase in liver weight was observed in both male and female rats. Relative kidney weight was also increased in the high dose groups. There was no gross pathological finding at terminal sacrifice. Microscopic histopathological examination did not show any lesion in terms of correlation with administration of the test substance. The results suggest that under the conditions employed in this study no observable effect level (NOEL) of the test substance be 52 mg/kg/day.