• Radiation Oncology Journal
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• v.20 no.2
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• pp.147-154
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• 2002

Purpose : Gingko biloba extract (GBE), a natural product extracted from Gingko leaves, is known to increase the radiosensitivity of tumors. This radiosensitization probably arises from the increase in the peripheral blood flow by decreasing the blood viscosity and relaxing the vasospasm. The influence of a GBE on the metabolic status in fibrosarcoma II (FSall) of a C3H mouse was investigated using $^{31}P$ magnetic resonance spectroscopy (MRS). Materials and Methods : Eighteen C3H mice with fibrosarcoma II $(from\;100\;mm^3\;to\;130\;mm^3)$ were prepared for this experiment. The mice were divided into 2 groups; one (9 mice) without a priming dose, and the other (9 mice) with a priming dose of GBE. The GBE priming dose (100 mg/kg) was administered by an intraperitoneal (i.p.) injection 24 hours prior to the measurement. First $^{31}P$ MRS spectra were measured in the mice from each group as a baseline and test dose of GBE (100 mg/kg) was then administered to each group. One hour later, the $^{31}P$ MRS spectra were measured again to evaluate the change in the energy metabolic status. Results : In the group without the priming dose, the mean pH, PCr/Pi, PME/ATP, Pi/ATP, PCr/(Pi+PME) values 1 hour after the test dose were not changed significantly compared to the values at the baseline. However, in the group with the priming dose, the mean PCr/Pi, Pi/ATP, PCr/(Pi+PME) values 1 hour after the test dose changed from the baseline values of 0.49, 0.77, 0.17 to 0.74, 0.57, 0.28 respectively. According to the paired t-test, the differences were statistically significant. Conclusion : The above findings suggest that the metabolic status is significantly improved after administering GBE if the priming dose is given 24 hours earlier. This shows that the radiosensitizing effect of GBE is based on the increase of tumor blood flow and the improvement in the metabolic status.

• Journal of Korea Foresty Energy
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• v.25 no.2
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• pp.28-33
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• 2006

This study was conducted to find potentialities of the leaves of gingko tree (Gingko biloba L.) which has been planted as a roadside tree in Korea because of its resistance on air pollution, insect, fungi, etc. Various amounts of the leaves were mixed with wasted wood particles to manufacture particleboard. Their influences on physical and mechanical properties and the formaldehyde emission of PB were investigated. Physical and mechanical properties, such as density, modulus of rupture (MOR), and internal bond (IB) strength, of manufactured particleboard were not much different from those of control board. Formaldehyde emission values were decreased with increasing amount of leaves in PB prepared. Especially, particleboard made with 3 percent of leaves was decreased to $1.66mg/{\ell}$ in formaldehyde emission, which is about 40% lower emission than that of control. From these results, the leaves of gingko tree may be considered as a formaldehyde emission lowering additive in a functional PB manufacturing process.

• Biomedical Science Letters
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• v.23 no.2
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• pp.80-88
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• 2017

Ginkgo biloba extract (EGb 761) is a standardized extract of Ginkgo biloba leaves and has anti- atherosclerosis properties. Many patients with atherosclerosis disorders take Ginkgo biloba extracts to supplement current therapy. In addition, normal healthy individuals also take Ginkgo biloba extracts for prophylactic purposes. However, it is unknown whether supplementation of Gingko biloba extracts in healthy individuals offer a benefit. In this study, we assessed whether EGb 761 could provide beneficial effects on serum cholesterol levels in normal mice. Wild-type C56Bl/6 mice were orally administered EGb 761 at 25 mg/kg (Group 3) or 50 mg/kg (Group 4) every other day for 40 days. We found that the serum levels of HDL-cholesterol (HDL-C) were significantly increased in EGb 761 and lovastatin treated groups. Treatment with EGb 761 and lovastatin resulted in reduced serum total cholesterol and LDL-cholesterol (LDL-C) compared to control group. Serum lecithin cholesterol acyltransferase (LCAT) levels were higher in EGb 761 and lovastatin treated group compared to the control group. However, no difference was observed in serum APO A-I levels between the control group and treatment group. These results suggest that EGb 761 can increase HDL-C resulting in increased serum LCAT levels.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1074-1079
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• 2006

As part of our research on phytochemicals that exert protective effects against diseases related to reactive nitrogen species, we have evaluated the scavenging activity of the yellow leaves of Ginkgo biloba on $ONOO^{-}$. The methanol extract and ethyl acetate fraction obtained from yellow leaves of G. biloba evidenced a marked scavenging activity on authentic $ONOO^{-}$. Repeated column chromatography of the active ethyl acetate soluble fraction on silica gel, Sephadex LH-20, and RP-18, resulted in the purification of 15 known compounds, including sciadopitysin (1), ginkgolide B (2), bilobalide (3), isoginkgetin (4), kaempferol (5), luteolin (6), protocatechuic acid (7), bilobetin (8), amentoflavone (9), ${\beta}-sitosterol$ glucopyranoside (10), kaempferol 3-O-rhamnopyranoside (11), kaempferol 3-O-glucopyranoside (12), kaempferol $3-O-[{6^{'}-O-p-coumaroyl-{\beta}-D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-L-rhamnopyranoside]$ (13), kaempferol 3-O-rutinoside (14), and 6-hydroxykynurenic acid (15). Among the compounds isolated, flavonoids (5, 6 and 11-14), protocatechuic acid (7), and 6-hydroxykynurenic acid (15) all exhibited marked scavenging activities on authentic $ONOO^{-}$. The $IC_{50}$ values of 5-7, 11-14 and 15 were as follows: $2.86{\pm}0.70,\;2.30{\pm}0.04,\;2.85{\pm}0.10,\;5.60{\pm}0.47,\;4.16{\pm}1.65,\;2.47{\pm}0.15,\;3.02{\pm}0.48,\;and\;6.24{\pm}0.27\;{\mu}M$, respectively. DL-Penicillamine ($IC_{50}=4.98{\pm}0.27\;{\mu}M$) was utilized as a positive control. However, the other compounds (1-4, 8-10) exerted no effects against $ONOO^{-}$.

• Biomedical Science Letters
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• v.20 no.4
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• pp.227-236
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• 2014

Ulcerative colitis (UC) is a serious gastrointestinal tract disease characterized by recurrent chronic inflammation and mucosal damage of the gastrointestinal tract. The conventional therapies of choice are anti-inflammatory agents, steroids and anti-TNF-${\alpha}$ therapy. However, inherent limitations in these therapies have steered many UC patients to supplement existing therapies with alternative medicinal products. In the current study, we tested the efficacy of Gingko bilola extract (EGb 761) in abating colonic inflammation in a DSS-induced murine model of colitis. C57BL/6 mice were administered 2% DSS in the drinking water for 7 days, then regular water for 7 days, and then 2% DSS for an additional 7 days. EGb 761 (1 mg/dose) was oral gavaged daily for the duration of the experiment. At the termination of the experiment, mice treated with EGb+DSS showed higher body weight, lower spleen weight and longer colon length compared to mice treated with DSS alone. HE-stained colon tissues also exhibited less histologic inflammation in mice treated with EGb+DSS mice compared to mice treated with DSS alone. The serum levels inflammatory cytokines, KC and TNF-${\alpha}$, were also decreased in mice treated with EGb+DSS compared to mice treated with DSS alone. Finally, addition of EGb 761 to TNF-${\alpha}$ treated colonic cell line (HT29/c1) decreased secretion of IL-8 in vitro. These results collectively suggest that EGb 761 abates induction of colitis in DSS-induced model of colitis in mice.

• The Korean Journal of Community Living Science
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• v.16 no.4
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• pp.95-102
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• 2005

The present study was performed to investigate the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and Proly1 endopeptidase (PEP) inhibitory activities of plant extracts. The whole extract of Fragaria yezoensis inhibited the DPPH radical by $90.4\%$ and the stem of Gingko biloba, Gardenia jasminoides for. grandiflora and Rhododendron yedoensa var. poukhanene, the loaves of Rhododendron mucronulatum var. ciliatum, Gardenia jasminoides for. grandiflora and Corylus sieboldiana var. mandshurice, the fruit of Cornus officinalis, and the root of Gingko biloba showed high DPPH radical scavenging activities. In the case of PEP inhibitory activities, high inhibition was observed in the whole Plant of Fragaria ananassa, Fragaria yezoensis and Hypericum erectum, the stem of Actinidia arguta and Rhododendron yedoensa var. poukhanese, the leaves of Rhododendron yedoensa var. poukhanense and Rosa davurica, the fruit of Cornus officinalis. and the root of Acer okamotoanum. There was significant correlation (P=0.000) between DPPH radical scavenging and prolyl endopeptidase inhibitory activities, thus some of plant extracts such as whole Fragaria yezoensis, fruit of Cornus officinalis had high activities in both DPPH-scavenging and prolyl endopeptidase inhibition. Therefore, it is required to examine the mechanical interaction between DPPH-scavenging and prolyl endopeptidase inhibitory activities and further studying plant extracts with both these activities is desired to develop agents for preventing and treating of Alzheimer's disease.

• Korean Journal of Clinical Laboratory Science
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• v.43 no.4
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• pp.179-187
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• 2011

Animal models are important tools in thrombosis research and preclinical drug development. In recent studies, ferric chloride ($FeCl_3$) has been widely used to induce arterial thrombosis in a variety of species. The purpose of this study was to find an optimal concentration of $FeCl_3$ and validate this model suited better for thrombosis research. A small piece of filter paper, soaked in $FeCl_3$ solution (10, 20 or 35%, v/v, in distilled water) was topically applied on the carotid artery of SD rats to measure the time to occlusion (TTO) and thrombus weight (TW) to ascertain 35%, as an optimal $FeCl_3$ concentration ($8.63{\pm}0.92min$; p =0.000, $0.79{\pm}0.03mg/mm$; p =0.000, respectively). To validate this experimental model, Ginkgo biloba special extract EGb761 (5, 10 or 30 mg/kg) as a reference agent administered by peritoneal route for 1h prior to the induction of thrombosis, showed significantly delayed TTO in a dose dependent manner ($18.50{\pm}2.17$, $29.17{\pm}1.83$, and $38.00{\pm}1.79min$, respectively) and significantly reduced TW and repaired collagen fibre in the injured vessel compare to vehicle group. Our results provide a simple, reproducible and well controlled in vivo screening system to induce thrombosis in rats by the topical application of 35% $FeCl_3$ to assess the efficacy of the new anti-thrombotic agents.

• Biomolecules & Therapeutics
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• v.15 no.3
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• pp.169-174
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• 2007

In the present study, we investigated the neuroprotective effects of standardized Ginkgo biloba extract (GBB) (total terpene trilactones, 13 ${\pm}$ 3%; biflavone, 4.5 ${\pm}$ 1.5%; flavonol glycoside, < 8%; proanthocyanidine, under detection limit) on ischemia-reperfusion-induced brain injury in the rats. Ischemia was induced by the intraluminal occlusion of the right middle cerebral artery for 2 h and reperfusion was continued for 22 h. GBB was orally administered, promptly prior to reperfusion and 2 h after. Total infarction volume in the ipsilateral hemispheres of ischemia-reperfusion rats were significantly reduced by treatment with GBB in a dose-dependent manner (P<0.05). The therapeutic time window of GBB was 3 h in this ischemia-reperfusion rat model. Furthermore, GBB also significantly inhibited increased neutrophil infiltration of ischemic brain tissue, as estimated by myeloperoxidase activity. These findings suggest that GBB plays a crucial protective role in ischemia-induced brain injury, in part, via inhibition of neutrophil infiltration, and suggest that this GBB could serve as a neuroprotective agent following transient focal ischemic brain injury.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.5
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• pp.275-278
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• 2003

Antioxidative activity is an important factor in inhibiting oxidative stress. The usual methods for determining antioxidative activity are time-consuming and cumbersome. They are also indirect processes that use biological material such as brain or liver microsome. This study therefore proposed a new method. Redoxpotential was determined using galvanic cell with or without the addition of various antioxidants or herbal extracts in zinc sulfate solution. The result was compared with the results from the TBA method and the peroxide value from sodium thiosulfate titration. All methods showed significant and dose-dependent enhancement of antioxidative activity by adding ascorbic acid, quercetin, ginseng, or gingko biloba extract. The result of redox potential using galvanic cell showed the smallest standard deviation and took the shortest time among the three methods. Therefore, the antioxidative potential of chemical substances and herbal extracts can be determined simply, directly and accurately in a short period of time using galvanic cell.

• The Korean Journal of Pharmacology
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• v.3 no.1
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• pp.19-25
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• 1967

Ginnol was obtained from Gingko Biloba L. by purification of its extract. Author observed the hyperventillation effect on pentobarbital anesthetized rabbit with Ginnol but there was no significant change in blood pressure. Morphine sulfate, even in large doses, did not alter the hyperventillation effect of Ginnol on rabbit. Blood chemistry of Ginnol treated rabbit showed slight increase in blood pH but within a physiological normal range, and increased total $CO_2$ content. While slight decreased $pCO_2$, increased ${HCO_3}^-$ and decreased $H_2CO_3$ and with decreased blood $Cl^-$ meant an uncompensatory alkalotic change but methemoglobin was not detected.