Ginkgo biloba extract alleviates fatty liver hemorrhagic syndrome in laying hens via reshaping gut microbiota

Background Ginkgo biloba extract(GBE)is evidenced to be effective in the prevention and alleviation of metabolic disorders,including obesity,diabetes and fatty liver disease.However,the role of GBE in alleviating fatty liver hemorrhagic syndrome(FLHS)in laying hens and the underlying mechanisms remain to be elucidated.Here,we investigated the effects of GBE on relieving FLHS with an emphasis on the modulatory role of GBE in chicken gut microbiota.Results The results showed that GBE treatment ameliorated biochemical blood indicators in high-fat diet(HFD)-induced FLHS laying hen model by decreasing the levels of TG,TC,ALT and ALP.The lipid accumulation and pathological score of liver were also relieved after GBE treatment.Moreover,GBE treatment enhanced the antioxidant activity of liver and serum by increasing GSH,SOD,T-AOC,GSH-PX and reducing MDA,and downregulated the expression of genes related to lipid synthesis(FAS,LXRα,GPAT1,PPARγand Ch REBP1)and inflammatory cytokines(TNF-α,IL-6,TLR4 and NF-κB)in the liver.Microbial profiling analysis revealed that GBE treatment reshaped the HFD-perturbed gut microbiota,particularly elevated the abundance of Megasphaera in the cecum.Meanwhile,targeted metabolomic analysis of SCFAs revealed that GBE treatment significantly promoted the production of total SCFAs,acetate and propionate,which were positively correlated with the GBE-enriched gut microbiota.Finally,we confirmed that the GBE-altered gut microbiota was sufficient to alleviate FLHS by fecal microbiota transplantation(FMT).Conclusions We provided evidence that GBE alleviated FLHS in HFD-induced laying hens through reshaping the composition of gut microbiota.Our findings shed light on mechanism underlying the anti-FLHS efficacy of GBE and lay foundations for future use of GBE as additive to prevent and control FLHS in laying hen industry.

Ginkgo biloba extract(EGb 761) attenuates lung injury induced by intestinal ischemia/reperfusion in rats:Roles of oxidative stress and nitric oxide

AIM： To investigate the effect of ginkgo biloba extract （EGb 761） on lung injury induced by intestinal ischemia/ reperfusion （ Ⅱ/R）. METHODS： The rat model of Ⅱ/R injury was produced by damping the superior mesenteric artery for 60 min followed by reperfusion for 180 min. The rats were randomly allocated into sham, Ⅱ/R, and EGb ＋Ⅱ/R groups. In EGb ＋Ⅱ/R group, EGb 761 （100 mg/kg per day） was given via a gastric tube for 7 consecutive days prior to surgery. Rats in Ⅱ/R and sham groups were treated with equal volumes of the vehicle of EGb 761. Lung injury was assessed by light microscopy, wet-todry lung weight ratio （W/D） and pulmonary permeability index （PPT）. The levels of malondialdehyde （MDA） and nitrite/nitrate （NO2/NO3）, as well as the activities of superoxide dismutase （SOD） and myeloperoxidase （MPO） were examined. Western blot was used to determine the expression of inducible nitric oxide synthase （iNOS）. RESULTS： EGb 761 markedly improved mean arterial pressure and attenuated lung injury, manifested by the improvement of histological changes and significant decreases of pulmonary W/D and PPT （P 〈 0.05 or 0.01）.Moreover, EGb 761 markedly increased SOD activity, reduced MDA levels and MPO activity, and suppressed NO generation accompanied by down-regulation of iNOS expression （P 〈 0.05 or 0.01）. CONCLUSION： The results indicate that EGb 761 has a protective effect on lung injury induced by Ⅱ /R, which may be related to its antioxidant property and suppressions of neutrophil accumulation and iNOS- induced NO generation. EGb 761 seems to be an effective therapeutic agent for critically ill patients with respiratory failure related to Ⅱ/R.

A ginkgo biloba extract promotes proliferation of endogenous neural stem cells in vascular dementia rats

The ginkgo biloba extract EGb761 improves memory loss and cognitive impairments in patients with senile dementia. It also promotes proliferation of neural stem cells in the subventricular zone in Parkinson＇s disease model mice and in the hippocampal zone of young epileptic rats. However, it remains unclear whether EGb761 enhances proliferation of endogenous neural stem cells in the brain of rats with vascular dementia. In this study, a vascular dementia model was established by repeatedly clipping and reperfusing the bilateral common carotid arteries of rats in combination with an intraperitoneal injection of a sodium nitroprusside solution. Seven days after establishing the model, rats were intragastrically given EGb761 at 50 mg/kg per day. Learning and memory abilities were assessed using the Morris water maze and proliferation of endogenous neural stem cells in the subventricular zone and dentate gyrus were labeled by 5-bromo-2-deoxyuridine immunofluorescence in all rats at 15 days, and 1, 2, and 4 months after model establishment. The escape latencies in Morris water maze tests of rats with vascular dementia after EGb761 treatment were significantly shorter than the model group. Immunofluorescence staining showed that the number and proliferation of 5-bromo-2-deoxyuridine-positive cells in the subventricular zone and dentate gyrus of the EGb761-treated group were significantly higher than in the model group. These experimental findings suggest that EGb761 enhances proliferation of neural stem cells in the subventricular zone and dentate gyrus, and significantly improves learning and memory in rats with vascular dementia.

Experimental Study on Inhibition of Neuronal Toxical Effect of Levodopa by Ginkgo Biloba Extract on Parkinson Disease in Rats

In order to observe neuronal toxical effect of Levodopa and investigate if using Levodopa together with Ginkgo Bilobar Extract (EGb) would be an workable method to treat Parkinson disease, rat models of Parkinson disease (PD) were made by injecting 6-OHDA stereotaxically to right side of the mesencephic ventral tegmental area (VTA) and substantia nigra pars compacta (SNc). Rotational behavioral observation, TUNEL, immunocytochemistry, Nissl's body staining were performed to measure the difference between group treated by Levodopa (50 mg/kg every day for 3 days, 5 days, 7 days, L-dopa group) and group treated by Levodopa combined with EGb (100 mg/ kg every day, E-D group). The results showed that in the L-dopa group, the numbers of apoptosis of substantial nigra, rings of rotational behavior were more than those in the E-D group (P<0. 05). The numbers of Nissl's cells in L-dopa group were fewer than in E-D group (P<0. 05). The results suggested that Levodopa had neur toxic effect and EGb may decrease the toxicity of levodopa. The combined use of EGb with Levodopa may be a workable method to treat PD and may be better than using Levodopa alone.

Protective effects of Ginkgo biloba extract on the ethanol-induced gastric ulcer in rats

AIM: To evaluate the preventive effect of Ginkgo biloba extract (GbE) on ethanol-induced gastric mucosal injuries in rats. METHODS: Female Wistar albino rats were used for the studies. We randomly divided the rats for each study into five subgroups: normal control, experimental control, and three experimental groups. The gastric ulcers were induced by instilling 1 mL 50% ethanol into the stomach. We gave GbE 8.75,17.5,26.25 mg/kg intravenously to the experimental groups respectively 30 min prior to the ulcerative challenge. We removed the stomachs 45 min later. The gastric ulcers, gastric mucus and the content of non-protein sulfhydryl groups (NP-SH), malondialdehyde (MDA), c-Jun kinase (JNK) activity in gastric mucosa were evaluated. The amount of gastric juice and its acidity were also measured. RESULTS: The findings of our study are as follows: (1) GbE pretreatment was found to provide a dose-dependent protection against the ethanol-induced gastric ulcers in rats; (2) the GbE pretreatment afforded a dose-dependent inhibition of ethanol-induced depletion of stomach wall mucus, NP-SH contents and increase in the lipid peroxidation (increase MDA) in gastric tissue; (3) gastric ulcer induced by ethanol produced an increase in JNK activity in gastric mucosa which also significantly inhibited by pretreatment with GbE; and (4) GbE alone had no inhibitory effect on gastric secretion in pylorus-ligated rats. CONCLUSION: The finding of this study showed that GbE significantly inhibited the ethanol-induced gastric lesions in rats. We suggest that the preventive effect of GbE may be mediated through: (1) inhibition of lipid peroxidation; (2) preservation of gastric mucus and NP-SH; and (3) blockade of cell apoptosis.

Ginkgo biloba leaf extract improves the cognitive abilities of rats with D-galactose induced dementia

Standardized Ginkgo biloba leaf extract has been used in clinical trials for its beneficial effects on brain func- tions, particularly in dementia. Substantial experimental evidences indicated that Ginkgo biloba leaf extract （EGB） protected neuronal cells from a variety of insults. We investigated the effect of EGB on cognitive ability and protein kinase B （PKB） activity in hippocampal neuronal cells of dementia model rats. Rats received an intra- peritoneal injection of D-galactose to induce dementia. Forty-eight Spraque-Dawley rats were randomly divided into six groups, including the control group, D-galactose group （Gal）, low-dose EGB group （EGB-L）, mid-dose EGB group （EGB-M）, high-dose EGB group （EGB-H） and treatment group. The EGB-L, EGB-M and EGB-H groups were administered with EGB and D-galactose simultaneously. Y-maze, cresyl violet staining, TUNEL assays and immunohistochemistry staining were performed to detect learning and memory abilities, morpho- logical changes in the hippocampus, neuronal apoptosis and the expressing level of phospho-PKB, respectively. Rats in the Gal group showed decreased abilities of learning and memory, and hippocampal pyramidal cell layer was damaged, while EGB administration improved learning and memory abilities. The Gal group exhibited many stained, condensed nuclei and micronuclei, either isolated or within the cytoplasm of cells （39.5 ± 1.4）. Apoptotic cells decreased in the groups of EGB-L （35.9±0.9）, EGB-M （16.8± 1.0） and EGB-H （10.1±0.8）, and there were statistical significances compared with the Gal group. Immunoreactivity of phospho-PKB was localized diffusely throughout the cytosol of cells in all groups, while the immunoreactivity of the Gal group was weak. EGB signifi- cantly attenuated learning and memory impairment in a dose-dependent manner, while it could decrease the nmber of TUNEL-positive cells, and increase the activity of PKB. Our results demonstrated that EGB attenuated memory impairment and cell apoptosis in galactose-induced dementia model rats by activating PKB.

The Effect of 2,5-hexanedione on Myelin Protein Zero Expression,and Its Mitigation Using Ginkgo Biloba Extract

Objective To investigate the role of myelin protein zero （P 0） in 2,5-hexanedione （2,5-HD）-induced peripheral nerve injury,and the protective effect of Ginkgo biloba extract （Egb761） on 2,5-HD-induced toxic peripheral neuropathy.Methods After 4 weeks of treatment with 2,5-HD at different doses （50,100,200,400 mg/kg） in rats,changes in the levels of P 0 in rat sciatic nerves was investigated,and the effect of Egb761 on 2,5-HD-induced toxic peripheral neuropathy was studied.Results The blood-nerve barrier （BNB） permeability of the sciatic nerve increased,and the expression of P 0 mRNA and P 0 protein decreased in a dose-dependent manner after treatment with 2,5-HD for 4 weeks.Pretreatment with Egb761 protected against BNB interruption,and inhibited P 0 mRNA and protein reduction during 2,5-HD treatment.Pretreatment with Egb761 significantly reduced loss of body weight （P0.01） and mitigated gait abnormalities （2.85±0.22） induced by 400 mg/kg 2,5-HD （P0.01）.It also reduced the signs of neurotoxicity induced by 2,5-HD.Conclusion 2,5-HD inhibited the expression of P 0 in a dose-dependent manner,and this may be an important mechanism by which toxic peripheral neuropathy is induced by 2,5-HD.Egb761 has a protective effect against 2,5-HD-induced peripheral neurotoxicity in rats.

Effects of extract from Ginkgo biloba on carbon tetrachloride-induced liver injury in rats

AIM： To study the effects of extract from Ginkgo biloba （EGb） containing 22% flavonoid and 5% terpenoid on chronic liver injury and liver fibrosis of rats induced by carbon tetrachloride （CCh）. METHODS： All rats were randomly divided into control group, CCl4-treated group, colchicine-treated group and EGb-protected group. Chronic liver injury was induced in experimental groups by subcutaneous injection of CCh and fed with chows premixed with 79.5% corn powder, 20% lard and 0.5% cholesterol （v/v）. EGb-protected group was treated with EGb （0.5 g/kg body weight per day） for 7 wk. At the end of wk 8, all the rats were killed. Liver function, liver fibrosis, oxidative stress and expression of transforming growth factor β1 （TGF-β1） a-smooth muscle actin （α-SMA） and type I collagens in liver were determined. In addition, pathology changes of liver tissue were observed under light microscope. RESULTS： The levels of alanine aminotransferase （ALT）, aspartate aminotransferase （AST） and albumin （AIb） in EGb-protected group were notably improved as compared with the CCL4-treated group （P 〈 0.01）. The contents of serum hyaluronic acid （HA）, type III procollagen （PCⅢ）, type IV collagen （CIV） and the expression of hepatic tissue TGF-β1, α-SMA and type I collagen in EGb-protected group were significantly lower than those in CCL4-treated groups （P 〈 0.05, P 〈 0.01）. The degrees of liver fibrosis in EGb-protected groups were lower than those in CCL4-treated groups （6.58 ±1.25 vs 9.52 ± 2.06, P 〈 0.05）. Compared to the CCL4-treated group, the levels of plasma glutathoine peroxidase （Se-GSH-Px）, superoxide dismutase （SOD） and malondialdehyde （MDA） were strikingly improved also in EGb-protected group （P 〈 0.05, P 〈 0.01）. CONCLUSION： EGb resists oxidative stress and thereby reduces chronic liver injury and liver fibrosis in rats with liver injury induced by CCl4.

Protective Effect of Ginkgo Biloba Leaf Extract on Learning and Memory Deficit Induced by Aluminum in Model Rats

Objective： To examine the protective effect of Ginkgo biloba leaf extract （GbE） on learning and memory deficit induced by aluminum chloride （AlCl3）, and explore its mechanisms. Methods： The rat models with learning and memory deficit were induced by administering via gastrogavage and drinking of AlCl3 solution. And the model rats were treated with GbE at the dose of 50, 100, 200 mg/kg every day for 2 months accompanied with drinking of AlCl3 solution, respectively. Their abilities of spatial learning and memory were tested by Morris water maze, and the acetylcholinesterase （ACHE） activity in serum was assayed with chemical method, the AChE expression in hippocampus was observed by immunohistochemistry assay, and then quantitative analysis was done by BI 2000 image analysis system. Results： Learning and memory deficit of rats could be induced by AlCl3 solution （P〈0.01）, and AChE expressions in rats hippocampus were increased （P〈0.01）; GbE ameliorated learning and memory deficit and reduced AChE expression in rats hippocampus in a dose-dependent manner, while GbE significantly increased serum AChE activity at the dose of 200 mg/kg each day （P〈0.05）. Conclusion： GbE can ameliorate learning and memory deficit induced by AlCl3, which may be due to its inhibition of the AChE expression in hippocampus.

Determination of the Flavonoids from Ginkgo Biloba Extract by High Performance Liquid Chromatography

HPLC method for analysis of the flavonoids from ginkgo biloba extract (GBE) was studied. By suitable selection of columns. symmetrical chromatographic peaks were obtained without using acidic modifier in the mobile phase, which can eliminate the time for cleaning the chromatographic system and simplify the analystic method for GBE Experimental conditions: column: Hypersil BDS C-18, 5mumx4x250 mm: column temperature: 35degreesC; mobile phase: 46% methanol-54% water; flow rate: 0.7 mL/min; detection wavelength: 360nm.

Activity of Ginkgo biloba Extract and Quercetin on Thrombomodulin Expression and Tissue-type Plasminogen Activator Secretion by Human Umbilical Vein Endothelial Cells

Objective In order to investigate the pharmacological properties of Ginkgo biloba extract （GBE） on improving blood circulation, the regulating action of GBE and quercetin （a main flavonoid ingredient in GBE） on thrombomodulin （TM） expression and tissue-type plasminogen activator （t-PA） secretion was studied. Methods Using flow cytometer and gel image system respectively, we evaluated the TM expression and the t-PA secretion by human umbilical vein endothelial cells （HUVECs） in vitro. Results The increase of TM expression on HUVECs surface was induced by GBE rather than quercetin in a dose- and time-dependent manner. Both GBE and quercetin increased the t-PA release significantly. Conclusion The effect of GBE on improving blood circulation may be partly attributed to its promoting TM expression and t-PA secretion by endothelial ceils, and quercetin participated in the effect of GBE on t-PA secretion. However, the action of GBE on increasing TM expression needs further study.

Meta-analysis of Ginkgo biloba extract for the treatment of Alzheimer's disease

OBJECTIVE：To evaluate the effect of Ginkgo biloba extract on Alzheimer＇s disease using meta-analysis.DATA SOURCES：The following sources were used for articles concerning Ginkgo biloba extract for the treatment of Alzheimer＇s disease：Western biomedical journal literature databases,Chinese Biomedical Literature Database,Chinese Journal Full-text Database,Chinese Science and Technology Journal Full-text database.DATA SELECTION：Randomized controlled trials addressing Ginkgo biloba extract for the treatment of Alzheimer＇s disease were selected.The pathway and method of information collection were identical between treatment and control groups.Mild and moderate Alzheimer＇s disease patients scoring ≤ 26 points on the mini-mental state examination were included.Subjects met the diagnostic criteria for dementia by the American Psychiatric Association＇s ＂Diagnostic and Statistical Manual of Mental Disorders＂ Fourth revised edition.The quality of included literature was assessed by two authors.Meta-analysis was performed by RevMan4.2 software which was provided by the Cochrane Collaboration.Heterogeneity,sensitivity analysis,and bias evaluation were conducted.MAIN OUTCOME MEASURES：Scores of mini-mental state examination,ADAS-cog,and Syndrom-Kurztest.RESULTS：The five included randomized controlled trials contained 819 patients.Meta-analysis showed that the Syndrom-Kurztest score was significantly decreased（weighted mean difference =-2.32; 95%CI =-3.12,-1.52; P 〈 0.01） compared with the control group.No significant difference was found in the mini-mental state examination and ADAS-cog score（P 〉 0.05）.However,there was a tendency to elevate mini-mental state examination score and to reduce the ADAS-cog score.CONCLUSION：Ginkgo biloba extract shows good therapeutic effects for mild and moderate Alzheimer＇s disease.However,high-quality,randomized,double-blind,and controlled trials are needed to further confirm its therapeutic effects.

The Effect of Ginkgo Biloba Extract on the Expression of PKCα in the Inflammatory Cells and the Level of IL-5 in Induced Sputum of Asthmatic Patients

To investigate the effect of the Ginkgo Biloba Extract （GBE） on the asthma and examine its possible mechanisms, 75 asthma patients were divided into 4 groups and the patients were respectively treated with fluticasone propionate for 2 weeks or 4 weeks, or treated with fluticasone propionate plus GBE for 2 weeks or 4 weeks. Fifteen healthy volunteers served as healthy controls. Sputum inhalation with inhaling hypertonic saline （4%-5%） was performed. Lung ventilatory function and forced expiratory volume in one second （FEVI） were measured. The numbers of different cells in induced sputum were calculated. The expression of PKCα in the cells was immunocytochemically detected and the percentages of positive cells in different cells were counted. Interleukin-5 （IL-5） in sputum supernatants was detected with enzyme-linked immunosorbent assay. The percentage of eosinophils, lymphocytes, PKCα positive inflammatory cells and the concentration of IL-5 in asthmatic patients were higher than those in the controls （P〈0.05）, and the eosinophils, lymphocytes, positive expression of PKCα and the level of IL-5 were significantly decreased in asthmatic patients after they were treated with fluticasone propionate or fluticasone propionate plus GBE. However, they were still significantly higher than those of the controls. Compared to the group treated with glucocorticosteroid for 2 weeks, no significant decrease was found in the percentage of eosinophils, lymphocytes, PKCα positive inflammatory cells and the IL-5 in the supernatant of induced sputum. Compared with the group treated with glucocorticosteroid for 2 or 4 weeks, significant decrease in the same parameters was observed in the group treated with fluticasone propionate and GBE for 4 weeks. The IL-5 level in the supernatant of induced sputum was positively correlated with the percentage of PKCα-positive inflammatory cells and the percentage of eosinophils in the induced sputum in asthma patient groups respectively （n=150, r=0.83, P〈0.01; n=150, r=0.76, P〈0.01）. The FEVI was negatively correlated with the percentage of PKCα-positive inflammatory cells and the IL-5 levels in supernatant of induced sputum in asthma patients respectively （n=150, r=-0.77, P〈0.01; n=150, r=- 0.64, P〈0.01）. It is concluded that GBE could significantly decrease the infiltration of inflammatory cells such as eosinophils and lymphocytes in the asthmatic airway and relieve the airway inflammation. GBE may decrease the activation of the PKCα in the inflammatory cells and thereby decrease the IL-5 level in induced sputum. GBE may be used as a complement to the glucocorticosteroid therapy for asthma.

Protective effects of ginkgo biloba leaves extract on peroxide-induced oxidative stress damage in PC12 cells

BACKGROUND： Extracts of ginkgo biloba leaves （EGB） and its metabolites have been reported to enhance brain function and nerve behavior. It has also been hypothesized that they can protect neurons from oxidative stress. OBJECTIVE： To investigate protective effects of EGB on peroxide （H2O2）-induced oxidative stress damage in PC12 cells. DESIGN： Observational contrast study. SETTING： Department ofPathophysiology, Guangdong Pharmacological College. MATERIALS： EGB was provided by Xi＇an Fujie Biotechnological Development Company; 1640 culture medium, methylthiazolyl tetrazolium （MTT）, trypsin and dimathyl sulfoxide （DMSO） by Sigma Company; PC12 cell strain by Cell Center of Medical College of Zhongshan University; calf serum by Hangzhou Sijiqing Bioengineering Company; lactate dehydrogenase （LDH） kit by Nanjing Jiancheng Bioengineering Research Institute. METHODS： The experiment was carried out in Department of Cell Biology of Guangdong Pharmacological College from June to December 2005. ①Cell culture： PC12 cells were cultured in 1640 medium containing 200 g/L fetal calf serum. The cells were diluted to 1 × 10^7 L^-1 and washed every two days. Those cells were used to experiment until they grew in logarithm on solid wall. ② Grouping and intervention： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates with the density of 200 μ L/hole and divided into three groups： normal control group （routinely adding media）, H2O2 group （treating with media and H2O2 for 20 hours） and EGB group （adding media, 100μmol/L EGB and 100 μmol/L H2O2）. ③ MTT assay： PC12 cells （1 × 10^8L^-1） were plated in 96-well plates and divided into three groups with 8 holes for each group. Under sterile condition, cells were added with 5 g/L MTT （100μL） and cultured for 4 hours. And then, 200 μ L DMSO fluid was added and shaken for 30 minutes until blue crystal products formed were dissolved soundly ④ Experimental evaluation： Absorbance （A） at 630 nm was measured and LDH activity was measured at the same time. MAIN OUTCOME MEASURES： Results of MTT assay and LDH activity. RESULTS： ① Results of MTT assay： A value was lower in the H2O2 group than that in the normal control group （P 〈 0.01）, while A value was higher in the EGB group than that in the H2O2 group （P 〈 0.01）. ② LDH activity： LDH activity was higher in the H2O2 group than that in the normal control group （P 〈 0.01 ）, while LDH activity was lower in the EGB group than that in the H2O2 group （P 〈 0.01）. CONCLUSION： EGB can inhibit H2O2-induced oxidative stress damage in PC12 cells possibly by preventing damage to the cell membrane.

Protective effects of Ginkgo biloba extract on 6-hydroxydopamine-induced apoptosis in PC12 cells

The present study analyzed the protective effects of Ginkgo biloba extract against 6-hydroxydopamine-induced PC12 cell apoptosis in a model of Parkinson＇s disease. The results showed that Ginkgo biloba extract had a potent cytoprotective action and inhibited apoptosis of PC12 cells induced by 6-hydroxydopamine. Ginkgo biloba extract decreased the ratio of Bax to Bcl-2 and markedly inhibited the activation of p53 and caspase-3. These experimental findings indicate that Ginkgo biloba extract may significantly reduce the effects of oxidative stress induced by 6-hydroxydopamine in PC12 cells and suppress cell apoptosis. The potential effects of Ginkgo biloba extract might be greater than those of levodopa in the treatment of Parkinson＇s disease.

Ginkgo biloba leaf extract effects on inducible nitric oxide synthase, Bcl-2, and Bax expression in rat models of spinal cord injury

BACKGROUND：Ginkgo biloba leaf extract exhibits neuroprotective effects in spinal cord injury. However, the mechanisms of action remain unclear. OBJECTIVE： To investigate inducible nitric oxide synthase （iNOS） and Bcl-2/Bax expression in the injured spinal cord, and to explore the neuroprotective mechanisms of ginkgo biloba leaf extract in rats with spinal cord injury. DESIGN, TIME AND SETTING： The randomized, controlled, cell molecular biology experiment was performed at Soochow University, China from March 2007 to March 2008. MATERIALS： A total of 120 healthy, adult Sprague Dawley rats were selected for this study. Rat models of moderate acute thoracic （T9） spinal cord injury were established using the modified Allen method. Shuxuening injection was obtained from Zhenbaodao Pharmaceutical Co., Ltd., China. Methylprednisolone was purchased from North China Pharmaceutical Co., Ltd. METHODS： All rats were equally and randomly divided into four groups. Only the spinal cord was exposed in the sham operation group rats. In the trauma group, rats were not treated with drugs following spinal cord injury. Rats in the hormone group were intraperitoneally injected with 30 mg/kg methylprednisolone following spinal cord injury. Rats in the ginkgo biloba leaf extract group were intraperitoneally infused with a 1.0 mL/kg Shuxuening injection per day. MAIN OUTCOME MEASURES： At 1 hour, as well as 1, 3, 5, 7, and 14 days after spinal cord injury, iNOS- and Bcl-2/Bax-positive cells were quantified with immunohistochemistry. Pathological changes were detected using hematoxylineosin staining under an optical microscope. RESULTS： Spinal cord injury in the ginkgo biloba leaf extract and hormone groups was milder compared with the trauma group. Demyelination was significantly ameliorated and the necrotic cavity was obviously reduced in the injured spinal cord of rats in the ginkgo biloba leaf extract and hormone groups at each time point. iNOS expression was increased in the injured spinal cord, and reached a peak at 5 days. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract and hormone groups compared with the trauma group （P 〈 0.05-0.01）. The number of iNOS-positive cells was lower in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury （P 〈 0.05）. Bcl-2 expression reached a peak at 3 days, and Bax expression reached a peak at 5 days following rat spinal cord injury. Bcl-2 expression was increased, but Bax expression was decreased in the ginkgo biloba leaf extract and hormone groups compared with the trauma group （P 〈 0.05-0.01）. Bcl-2 expression was greater, but Bax expression was reduced in the ginkgo biloba leaf extract group compared with the hormone group at 7 and 14 days after spinal cord injury （P 〈 0.05）. CONCLUSION： Ginkgo biloba leaf extract exhibits neuroprotective effects by upregulating Bcl-2 expression, downregulating Bax expression, and significantly inhibiting high expressions of iNOS in the injured spinal cord. The neuroprotective effects of ginkgo biloba leaf extract are greater compared with methylprednisolone at 1 week after spinal cord injury.

Effects of Ginkgo biloba extract on expression of biomarkers during aflatoxin B_1-induced hepatocarcinogenesis in Wistar rats

Objective： The aim of this study was to study the effect of Ginkgo biloba extract （EGb761） on metabolism of afiatoxin B1 （AFB1） in Wistar rats. Methods： Seventy one Wistar rats were assigned at random to groups A, B and C. Rats in groups A, B were injected with AFB1 （intraperitoneal, 100-200 ug/kg body weight, 1-3 times/week）. Group C was normal control. Rats in group B were fed in food with EGb761, while rats in groups A, C were given normal food. Blood samples were collected and liver biopsies were performed on the 14th, 28th and 42nd week. All the rats were sacrificed on the 64th week. The incidence of hepatocarcinoma was investigated. The hepatic phase I drug-metabolizing enzyme Cytochrome-P450 （CYP450） and phase II metabolizing enzyme glutathione S-transferase （GST） were analyzed with spectrometry. Serum AFB1- lysine adduct levels were assessed with high performance liquid chromatography （HPLC）. The expression of 8-hydroxydeoxy- guanosine （8-OHdG） was measured with immunohistochemistry. Results： The incidence of hepatocellular carcinoma （HCC） in group B was significantly lower than that in group A （26.92% vs 76.00%, P 〈 0.001）. No HCC developed in group C. EGb761 showed no effects on the activities of CYP450 and GST in rat liver tissues. The level of AFB1-lysine adduct reached the peak （4356.01 pg/mg albumin） at the 14th week in group A. EGb761 significantly inhibited the formation of AFB1-lysine adduct in serum by 13.07% at the 14th week （P = 0.033）, and 73.63% at the 42nd week （P = 0.002）. The expression of 8-OHdG protein in rat liver tissues in group B was significantly lower than that in group A at the 28th, 42nd, and 64th week （P 〈 0.05）. Conclusion： The main mechanism underlying the effect of EGb761 in blocking hepatocarcinogenesis induced by AFB1 may not be fully attributable to its influence on the activity of liver phase I and phase II metabolizing enzymes. EGb761 inhibits the production of AFB1-lysine adducts, decreases the expression of 8-OHdG protein, and finally alleviates the DNA oxidative injury, which may be one of the mechanisms for the effects of EGb761 in inhibiting or delaying AFB1-induced hepatocarcinogenesis.

Ginkgo Biloba Extract Ameliorates Scopolamine-induced Memory Deficits via Rescuing Synaptic Damage

Objective Alzheimer’s disease(AD)is the most common age-related neurodegenerative disorder.Emerging evidence suggests that synaptic dysfunction is associated with the onset and progression of AD.Interestingly,Ginkgo biloba extract(EGb)is one of the most frequently investigated herbal medicines for enhancing cognition and alleviating neurodegenerative dementia.This study aimed to investigate the effect and the mechanism of EGb on AD-like synaptic disorders.Methods Scopolamine(SCO)-induced rats were used to mimic AD-like memory deficits.Morris water maze test and fear conditioning test were conducted to evaluate the memory status of rats in response to different treatments.Then,the synapse alterations were assessed by Golgi staining,and Western blotting was conducted to assess the protein expression of PSD95,GluN2B,synapsin-1,and synaptophysin.Reverse transcription quantitative polymerase chain reaction was applied to detect the mRNA expression of PSD95 and the levels of miR-1-3p/miR-206-3p.Results EGb supplement alleviated the learning and memory deficits induced by SCO in behavioral experiments.Moreover,EGb treatment attenuated synaptic damage elicited by SCO,manifested as increased dendritic spine density and the proportion of mushroom-type spines in hippocampal neurons.Further investigation indicated that EGb rescued the expression of synaptic-related proteins,especially PSD95,and decreased the levels of miR-1-3p/miR-206-3p in the rat hippocampus.Conclusion The application of EGb effectively treats SCO-induced memory impairments probably by suppressing miR-1-3p/miR-206-3p and elevating the expression of PSD95.

Ginkgo biloba Extract EGb 761® Improves Central Vestibular Vertigo in Patients Undergoing Vestibular Exercises: A Randomised Placebo-Controlled Trial

Background: Ginkgo biloba extract EGb 761® is widely used to treat various types of vertigo. Aims: An exploratory trial was conducted to evaluate the efficacy of EGb 761® in addition to vestibular exercises in central vestibular vertigo caused by vertebro-basilar ischaemia. Subjects and Methods: In this randomised, placebo-controlled, double-blind trial, 40 patients were enrolled in the vertigo clinic of a neurological university hospital and treated with daily doses of 240 mg EGb 761® or placebo for a period of 180 days. All patients regularly performed vestibular exercises in addition. Efficacy was assessed using: a visual analogue scale for the patients to rate the overall intensity of vertigo;a numeric scale for physician-rated change;a vertigo score based on intensity, duration, and frequency of vertigo;and electronystagmography. Results: Until day 180, the mean patient-rated intensity of vertigo decreased by 46% during EGb 761® treatment and by 19% with placebo (p ® group compared to the placebo group. Nystagmus or other eye movement disorders were present only in small subgroups of patients without sufficient statistical power to detect differences between treatment groups. Conclusions: EGb 761® alleviated vertigo caused by ischaemic lesions in the brainstem or cerebellum in patients undergoing vestibular exercises.

Effects of Ginkgo biloba extract on diabetic retinopathy:a meta-analysis and systematic review

Objective:The aim of present meta-analysis was to evaluate the clinical efficacy of Ginkgo biloba extract combined with conventional therapy in the treatment of diabetic retinopathy(DR).Methods:The randomized controlled trials(RCTs)of Ginkgo biloba extract adjuvant conventional therapy for treating DR were searched in PubMed,the Cochrane Library,China Knowledge Network(CNKI),China Biomedical Literature Service System(SinoMed),VIP Information Chinese Journal Service Platform(VIP),and Wanfang database.Two reviewers independently extracted data and conducted methodological quality assessment.Data analysis was performed using Revised Cochrane risk-of-bias tool for randomized trials(RoB 2).Results:A total of 9 RCTs involving 798 patients were included in current research.Meta-analysis showed that Ginkgo biloba extract combined with conventional medicine can improve total effective rate[OR=0.33,95%CI=(0.23,0.46),P<0.0001],visual acuity[OR=-0.11,95%CI=(-0.14,-0.07),P<0.0001]and visual field average defect[OR=0.59,95%CI=(0.53,0.65),P<0.0001].Conclusion:The available evidence indicated that Ginkgo biloba extract combined with conventional medicine can be beneficial for treating DR.However,our findings were warranted to verify by more large-scale,multi-center clinical trials.