Inhibition Effect of Ginkgo biloba Extract(EGb761) on the Phenotypic Switch of Vascular Smooth Muscle Cells through Regulation of APMK/KLF4 Signaling Pathway / 中国药学杂志

OBJECTIVE: To explore the effects of Ginkgo biloba extract (EGb761) on platelet derived growth factor (PDGF)-induced phenotypic switch of vascular smooth muscle cells (VSMCs) and its potential mechanisms. METHODS: VSMCs were cultured in vitro, and 20 ng•mL-1 PDGF was used to induce the phenotypic switch of VSMCs. MTT assay and wound healing assay were performed to determine the effects of various concentration (1, 10, 100 μg•mL-1) of EGb761 on cell proliferation and migration, respectively; immunofluorescence and Western blot assay were used to detect the arrangement of myofilament, the expression of phenotypic proteins including α-SMA, calopnin and OPN, as well as the protein expression of AMPK/KLF4 signaling pathway. RESULTS: Compared with the control group, PDGF significantly promoted the proliferation and migration of VSMCs. However, EGb761 treatment inhibited PDGF-induced cell proliferation and migration in a concentration-dependent manner. Compared with the control group, PDGF treatment induced disordered arrangement of myofilament and reduced the fluorescence intensity of F-actin. In addition, PDGF significantly decreased the expression of α-SMA and calponin, whrease increased the expression of OPN in VSMCs, when compared with the control group. VSMCs in PDGF+EGb761 group showed well-aligned myofilament and enhanced the fluorescence intensity of F-actin; the expressions of α-SMA and calponin were increased and OPN was decreased in the PDGF+EGb761 group when compared with the PDGF group. Meanwhile, as compared with the control group, PDGF increased the level of phosphorylated AMPK and the expression levels of KLF4, which was inhibited by the addition of EGb761 in a concentration dependent manner. After inhibition of AMPK/KLF4 signaling pathway with the use of specific AMPK pathway inhibitor compound C, the inhibitory effect of EGb761 on PDGF-mediated phenotypic switch of VSMCs was enhanced; vice versa, the activation of AMPK/KLF4 signaling pathway with AMPK pathway activator AICAR and the inhibitory effect of EGb761 on PDGF-mediated phenotypic switch of VSMCs were reversed. CONCLUSION: EGb761 inhibits PDGF-mediated phenotypic switch of VSMCs by targeting APMK/KLF4 signaling pathway.

Identification of a Novel Function of Extract of Gingko biloba (EGb 761®) as a Regulator of PYY Secretion and FFA4 Activation

Although the functions of a standardized extract of Gingko biloba leaves (EGb 761®) has been reported with regard to neurobiological properties, no attention has been paid to the impact of EGb 761® on the neuronal regulation of energy homeostasis. To evaluate the hypothesis that EGb 761® affect the secretion of peptide tyrosine tyrosine (PYY) and the activation of free fatty acid receptor 4 (FFA4), which are involved in the neuronal circuitries that control energy homeostasis by inducing the transfer of information about the influx of energy to the brain, we examined whether EGb 761® can stimulate PYY secretion in the enteroendocrine NCI-H716 cells and if EGb 761® can activate FFA4 in FFA4-expressing cells. In NCI-H716 cells, EGb 761® stimulated PYY secretion and the EGb 761®-induced PYY secretion was involved in the increase in intracellular Ca2+ concentration and the activation of FFA4. Furthermore, in FFA4-expressing cells, EGb 761® activated FFA4. These results suggest that EGb 761® may affect the control of energy homeostasis via the regulation of PYY secretion and FFA4 activation.

Ginkgo biloba extract (EGb761) did not express estrogenic activity in an immature rat uterotrophic assay

Ginkgo biloba is a dioecious tree that has been used in traditional Chinese medicine for about 5,000 years. In previous studies on Ginkgo biloba extract (EGb761) using in vitro systems, we confirmed that EGb761 has biphasic effects on estrogenicity. In this study, we evaluated the agonistic and antagonistic activities of EGb761 using a uterotrophic assay in immature female rats. To evaluate agonistic and antagonistic effects of EGb761 on uterus, 21-day-old immature Sprague-Dawley (SD) female rats were treated with EGb761 (100, 200, or 400 mg/kg) by oral gavage, 10 μg/kg of estradiol (E2) or 1 mg/kg tamoxifen (TM) by subcutaneous injection, or with EGb761 plus E2 or TM for 3 consecutive days. At the end of the treatment period, animals were sacrificed and their body weights and organ weights (liver, lung, spleen and kidney) were measured. In addition, estrogen-related gene expressions (IGFBP-1 in liver and CaBP-9 in uterus) were determined. During the experiment, no animal showed clinical signs, a change in body weight or died. EGb761 treatment alone had no effect on absolute/relative uterine weight, luminal epithelial cell height (LECH, μm), or luminal circumference (LC, μm). In addition, uterine weights, LECHs, and LC induced by E2 or TM were not significantly changed by EGb761 at any dose. These results collectively suggested EGb761 has no agonistic/antagonistic effects in utero.

Ginkgo biloba extract (EGb761) did not express estrogenic activity in an immature rat uterotrophic assay

Ginkgo biloba is a dioecious tree that has been used in traditional Chinese medicine for about 5,000 years. In previous studies on Ginkgo biloba extract (EGb761) using in vitro systems, we confirmed that EGb761 has biphasic effects on estrogenicity. In this study, we evaluated the agonistic and antagonistic activities of EGb761 using a uterotrophic assay in immature female rats. To evaluate agonistic and antagonistic effects of EGb761 on uterus, 21-day-old immature Sprague-Dawley (SD) female rats were treated with EGb761 (100, 200, or 400 mg/kg) by oral gavage, 10 μg/kg of estradiol (E2) or 1 mg/kg tamoxifen (TM) by subcutaneous injection, or with EGb761 plus E2 or TM for 3 consecutive days. At the end of the treatment period, animals were sacrificed and their body weights and organ weights (liver, lung, spleen and kidney) were measured. In addition, estrogen-related gene expressions (IGFBP-1 in liver and CaBP-9 in uterus) were determined. During the experiment, no animal showed clinical signs, a change in body weight or died. EGb761 treatment alone had no effect on absolute/relative uterine weight, luminal epithelial cell height (LECH, μm), or luminal circumference (LC, μm). In addition, uterine weights, LECHs, and LC induced by E2 or TM were not significantly changed by EGb761 at any dose. These results collectively suggested EGb761 has no agonistic/antagonistic effects in utero.

Protective role of Gingko Biloba extract in intestinal mucosal barrier of intestinal inflammation mouse / 重庆医学

Objective To investigate the protective role of Gingko Biloba extract (EGB 761) in intestinal mucosal barrier of intestinal inflammation model mouse.Methods Thirty mice were randomly divided into the control group,model group and EGB 761 group;the animal model was established;the general condition,body mass change,fecal occult blood and colon histopatho1ogical changes were observed,the expressions of occludin-1 proteins in colon tissue were detected by immunofluorescence.Results The body mass in the model group appeared to decrease,drinking water and eating food were significantly decreased compared with that in the control group.However after the EGB 761 intervention,the body mass of the model mice was significantly risen again;little inflammatory cells infiltration could be seen in the EGB 761 group,the inflammatory degree was significantly alleviated compared with the model group.The fluorescence distribution of the claudin-1,occludin and zo-1 in colonic tissues of the model group was more disperse compared with the normal group,the fluorescence intensity was weakened with rough edge;after EGB 761 intervention,the fluorescence in the EGB7 61 group was distributed along with the cellular membrane,the intensity was slightly weakened compared with the normal control group,but was still stronger than that in the model group.Conclusion EGB 761 can improve the inflammatory reaction in mouse colonic tissue,its mechanism may be related with its strengthening the protective effect of intestinal mucosal barrier.

Protective role of Gingko Biloba extract in intestinal mucosal barrier of intestinal inflammation mouse / 重庆医学

Objective To investigate the protective role of Gingko Biloba extract (EGB 761) in intestinal mucosal barrier of intestinal inflammation model mouse.Methods Thirty mice were randomly divided into the control group,model group and EGB 761 group;the animal model was established;the general condition,body mass change,fecal occult blood and colon histopatho1ogical changes were observed,the expressions of occludin-1 proteins in colon tissue were detected by immunofluorescence.Results The body mass in the model group appeared to decrease,drinking water and eating food were significantly decreased compared with that in the control group.However after the EGB 761 intervention,the body mass of the model mice was significantly risen again;little inflammatory cells infiltration could be seen in the EGB 761 group,the inflammatory degree was significantly alleviated compared with the model group.The fluorescence distribution of the claudin-1,occludin and zo-1 in colonic tissues of the model group was more disperse compared with the normal group,the fluorescence intensity was weakened with rough edge;after EGB 761 intervention,the fluorescence in the EGB7 61 group was distributed along with the cellular membrane,the intensity was slightly weakened compared with the normal control group,but was still stronger than that in the model group.Conclusion EGB 761 can improve the inflammatory reaction in mouse colonic tissue,its mechanism may be related with its strengthening the protective effect of intestinal mucosal barrier.

Protection strategies of typical herbal medicine patent in German and their enlighten on domestic pharmaceutical enterprises / 中草药

Herbal medicine and Chinese materia medica (CMM), Kampo, traditional medicine in Australia, and other traditional medicines have been an important part of the world medicine, and the patent protection strategies of herbal medicine and Kampo at the international level have been already quite mature. However, China have less experience in patent protection strategies of CMM, and apparently fall behind the herbal medicine patent protection strategies of European countries, especially Germany. In this paper, based on the perspective of research and development, the patent application and protection strategies of Tebonin® from Germany are analyzed in depth. Considering patent conservation status of CMM, some workable references for the domestic pharmaceutical enterprises of CMM in the field of research and development of new drugs are provided.

Effects of Extract of Ginkgo biloba Leaves EGb761 on MPP+-induced Injury in SH-SY5Y Cells / 中国中医药信息杂志

Objective To investigate the effects of extract of Ginkgo biloba leaves EGb761 on 1-methy-l 4-phenylpyridium (MPP+)-induced injury in human neuroblastoma SH-SY5Y cells; To discuss its mechanism of action.Methods Cell culture method was used and SH-SY5Y cell damage model was induced with different concentrations of MPP+ to build Parkinson’s disease model in vitro. The experiment was divided into control group, MPP+ model group, low-, medium-, and high-dose EGb761 groups. The survival rate was determined by MTT assay, and the apoptotic rate was detected by flow cytometry according to AnnexinV apoptosis detection kit. The cell morphology was observed by inverted microscope. NO content in SH-SY5Y cells was detected by Nitric acid reduction method.Results Compared with the control group, the survival rate of SH-SY5Y cells decreased and the apoptotic rate and NO content increased in the model group (P<0.05); Compared with the model group, the survival rate of SH-SY5Y cells increased and the apoptotic rate and NO content decreased in the low-, medium- and high-dose EGb761 groups (P<0.05).Conclusion EGb761 can protect MPP+-induced SH-SY5Y cell from damage by the inhibition of the content of NO free radical.

Insight into recently issued community herbal monograph on Ginkgo biloba L., folium and its impact on registration strategy of Ginkgo Folium products in EU / 中草药

In January, 2014, European Medicines Agency (EMEA) issued a draft for community herbal monograph on Ginkgo biloba L., folium. That means the community herbal monograph on Ginkgo biloba L., folium has been settled finally. This assay introduces the new Ginkgo monograph briefly, describes the two registering methods and requirements for herbal medicines in EU, and reads the new monograph in more detail. By analyzing the impact of the new monograph on Ginkgo Folium products, this monograph will offer a very important reference and basis for the herbal registration application of Ginkgo Folium products in EU.

Ginkgo biloba: A ‘living fossil’ with modern day phytomedicinal applications.

Ginkgo biloba has survived for over 200 million years now. With other members of this gymnosperm extinct, it is considered as a ‘living fossil’. Yinxing, as it is called in Chinese, is very popular in East Asia as a remedy for lung congestion, ischemia and asthma. In modern day medical practice, growing consideration is given to the extract from this tree as a line of treatment in many cancer conditions partly due to the side effects of conventional drugs of therapy. The extract has also anti-diabetic, anti-inflammatory and cardio- and hepatoprotective roles. These and other numerous recent applications of this important botanical drug are discussed in this review.

Gingko biloba extract (EGb 761) attenuates ischemic brain injury-induced reduction in Ca2+ sensor protein hippocalcin / 한국실험동물학회지

Gingko biloba extract 761 (EGb 761) protects neuronal cells from ischemic brain injury via a number of neuroprotective mechanisms. Hippocalcin is a calcium sensor protein that regulates intracellular calcium concentrations and apoptotic cell death. We investigated whether EGb 761 regulates hippocalcin expression in cerebral ischemia. Male Sprague-Dawley rats were treated with vehicle or EGb 761 (100 mg/kg) prior to middle cerebral artery occlusion (MCAO), and cerebral cortex tissues were collected 24 h after MCAO. A proteomic approach demonstrated reduction in hippocalcin expression in vehicle-treated animals during MCAO, whereas EGb 761 treatment prevented injury-induced decreases in hippocalcin expression. RT-PCR and Western blot analyses indicated that EGb 761 attenuates injury-induced decrease in hippocalcin. These results suggest that the maintenance of hippocalcin during cerebral ischemia contributes to the neuroprotective role of EGb 761.

Ginkgo biloba extract (EGb 761) prevents the ischemic brain injury-induced decrease in parvalbumin expression / 한국실험동물학회지

Ginkgo biloba extract (EGb 761) exerts a neuroprotective effect against ischemic brain injury through an anti-apoptotic mechanism. Parvalbumin is a calcium buffering protein that plays an important role in modulating intracellular calcium concentration and regulating apoptotic cell death. The aim of this study was to investigate whether EGb 761 affects parvalbumin expression in cerebral ischemic injury. Adult male Sprague-Dawley rats were treated with vehicle or EGb 761 (100 mg/kg) prior to middle cerebral artery occlusion (MCAO) and cerebral cortex tissues were collected 24 h after MCAO. A proteomic approach revealed a reduction in parvalbumin expression in the vehicle-treated animals, whereas EGb 761 pretreatment attenuates the ischemic injury-induced decrease in parvalbumin expression. RT-PCR and Western blot analyses clearly confirmed the fact that EGb 761 prevents the injury-induced decrease in parvalbumin. Moreover, the results of immunohistochemical staining showed that the number of parvalbumin-positive cells was lower in vehicle-treated animals than in sham-operated animals, and EGb 761 averted this decrease. Thus, these results suggest that the maintenance of parvalbumin expression is associated with the neuroprotective function of EGb 761 against neuronal damage induced by ischemia.

The Protective Effect of EGB761 on Vessels of Denervated Gastrocnemius in Rats and Its Mechanism / 华中科技大学学报（医学）（英德文版）

This study investigated the protective effect of EGB761 on blood vessels of denervated gastrocnemius of rat and its possible mechanism.Fifteen male adult SD rats were randomly divided into three groups:normal control group (n=3),control group (n=6) and EGB761-treated group (n=6).The rats in the control and EGB761-treated group underwent a neurotomy to bilateral sciatic nerves.Then,they were administered EGB761 [100 mg/(kg·d)] and isovolumic normal saline,respectively by gavage everyday.No treatment was given to the rats in the normal control group.Gastrocnemius was harvested at 1 and 3 week(s) postoperatively in each group.Immunohistochemical method was used to detect the ratio of capillary/fiber (CFR) of denervated gastrocnemius and the expression of VEGF,fetal liver kinase -l(Flk-1) receptor and HSP70 in the vascular wall.The results showed that in the normal control group,VEGF,Flk-1 and HSP70 were expressed in the vessel wall of gastrocnemius,with Flk-1 expressed only in the endothelial cell of vessels.CFR in the EGB761-treated group was significantly higher than that in the control group at 1 week and 3 week(s) after neurotomy.The expression of VEGF and Flk-1 in the vessel wall of both control and EGB761-treated group was much lower than that in the normal control group,and the expression of these proteins in the EGB761-treated group was decreased as compared with that in the control group.The expression of HSP70 in the vessel wall of both control and EGB761-treated groups was enhanced when compared with that in the normal control group,and it was substantially augmented in the EGB761-treated group in comparison to the control group.It was concluded that EGB761 has a protective effect on blood vessels of denervated gastrocnemius,which is related to the increased HSP70 expression but not the expression of VEGF and its receptor Flk-1.

The effects of antiphospholipid antibodies and EGb761 on the Schwann cells in vitro / 中国实用内科杂志

Objective To detect the effect of the antiphospholipid antibodies on the Schwann cells in vitro and to find if the Extract of Ginkgo biloba 761(EGb761)has any protective effects.Methods The immunoglobulins(Ig)were extracted from the serum of the patient with autoimmune polyneuropathies and those with controls.Ig only or Ig plus calf serum(served as complement)were added into the culture solutions of the Schwann cells.The density of the cell in one high power field,the cell perimeter and area were detected and compared to those blank and those controls.Results The shape of the Schwann cells in both the Ig and Ig plus calf serum solution were greatly changed.The densities of the cells in them were both lower than the blank ones,with more severe in the cells with calf serum.There was no significant different between the solutions with or without EGb761.Conclusion Ig from the patients with autoimmune polyneuropathies could attack the Schwann cells in vitro,with the existence of complements,the destruction was even more severe.No protection of EGb761 could be found in these situations.

Neuroprotective Effect of Extact of Ginko Biloba on the Retinal Ganglion Cells / 中国中医药信息杂志

Objective To investigate whether the extact of ginko biloba (EGb761) can protect the retinal ganglion cells (RGC) after acute high intraocular pressure induced retinal ischemia-reperfusion injury. Methods Thirty Sprague-Dawley rats were randomly divided into three groups. The negative control group, positive control group, treatment group were given normal saline 5 mL/kg, 1% erigeron breviscapus (vant) hand-mazz (EBHM) 5 mL/kg, 1% EGb761 5 mL/kg, respectively 2 hour after injury and every day after operation. Retinal ganglion cells were retrograde labeled by injection of 3% fluorogold (FG) into both side of superior colliculus 5 days before the death of the rats. Results The average survival rate of retinal ganglion cells were 61.46%, 72.73% and 76.20% in negative control group, positive control group and treatment group respectively. Conclusion EGb761 has neuroprotective effect on retinal ganglion cells in acute high intraocular pressure induced retinal ischemia-reperfusion injury.

Early Prediction of Hypoxic-Ischemic Brain Damage in Newbon Rats Using Proton Magnetic Resonance Spectroscopy and Neuroprotective Effect of EGb 761

PURPOSE: This study was designed to evaluated the relationship between the morphological changes of hypoxic-ischemic injured brain and the magnetic resonance spectroscopic (MRS) findings, and the efficacy of Egb 761, a free radical scavenger, as a neuroprotective agent for hypoxic-ischemic brain injury. METHODS: Seven-day old Sprague-Dawley rat pups were used. Right common carotid artery was ligated under halothene anesthesia. After a recovery period of 3 hours, they were divided into two groups : for group 1, EGb 761 100 mg/kg (treatment group) and for group 2, normal saline (control group) were given intraperitoneally. Both groups were exposed to 8% oxygen at 37degrees C for 90 minutes. Sixty-four rat pups (30 control, 34 treatment group) were examined with localized 1H MRS on days 1 and 7 after the hypoxic insult. One day 14, the degree of brain injury was scored by morphological changes. RESULTS: The 1H MRS obtained on day 1 after the hypoxic insult showed increased Lip/NAA and Lip/Cr ratios in the right cerebral hemisphere in comparison with those in the left hemisphere (P<0.01). The degree of morphological changes of the brain injury on day 14 correlated with both Lip/NAA and Lip/Cr ratios obtained on days! and 7 after the hypoxic insult [r=0.410, 0.457 on day 1, and r=0.749, 0.720 on day 7, respectively (P< 0.01)]. The therapeutic potential of EGb 761 for the hypoxic-ischemic brain seemed insignificant, as was evident from no differences between the control group and the EGb 761 treatment group in the Lip/NAA and Lip/Cr ratios as well as in morphological changes. CONCLUSION: Early changes of Lip/NAA and Lip/Cr ratios in the 1H MRS seems to be related to the degree of morphological changes in the rat brain of hypoxic-ischemic injury. Therefore, the increased lipid content of brain observed by 1H MRS can be used as a marker to predict the degree of the hypoxic-ischemic injury. The neuroprotectiveeffect of EGb 761 in hypoxic-ischemic brain injury is insignificant.

An Effect of Ginkgo Extract on Salicylate Ototoxicity in Guinea Pigs / 대한이비인후과학회지

BACKGROUND: The mechanism of salicylate ototoxicity is probably related to reversible biochemical or metabolic changes in the cochlea. Decreased cochlear blood flow seems to play an important role in salicylate ototoxicity. Several constituents of ginkgo extract have the action of increasing blood flow, antagonism of platelet activating factor and scavenger of free radicals. It might be thought that these activities of ginkgo extract could contribute to attenuate salicylate ototoxicity. OBJECTIVES: Whether the salicylate induced hearing loss could be attenuated by pretreatment with ginkgo extract. MATERIALS AND METHODS: Auditory brainstem response threshold changes were observed after the intramuscular injection of lysine salicylate(300mg/kg), or lysine salicylate with EGb 761(100mg/kg, single IP or 100mg/kg and 50mg/kg, IP, two times) pretreatment in each group of guinea pig. RESULTS: In the groups with Ginkgo extract pretreatment, the threshold changes were less severe and recovered earlier than in group with salicylate injection only(p<0.05). CONCLUSIONS: EGb 761 could attenuated the hearing loss after the injection of salicylate in guinea pig.

Delayed cardioprotection of Gingkgo biloba leaf extract and its mechanisms / 中草药

Objective To observe the delayed cardioprotective effect of the extract of Gingkgo biloba leaves(EGb761)and its possible mechanisms in rats.Methods Myocardial ischemia-reperfusion(I/R)injury was induced by 30 min of global ischemia and 30 min of reperfusion in isolated rat hearts.Heart rate(HR),coronary flow(CF),left ventricular pressure(LVP),and its first derivatives(+dp/dtmax)were recorded,and the releasing content of creatine kinase(CK),contents of malondialdehyde(MDA)and nitric oxide(NO)in myocardial tissues were measured.Results Single ig EGb761(50 or 100 mg/kg)at 24 h before I/R were done could significantly attenuate the damage of cardiac function(LVP and +dp/dtmax)and the lowering of NO level in myocardial tissues,and inhibit the increasing in CK release and MDA level induced by I/R in myocardial tissues.The delayed cardioprotective effects of EGb761 were markedly inhibited by pretreatment with L-NAME(5 mg/kg),an inhibitor of NO synthase,or HMR1883(3 mg/kg),an antagonist of sarcolemmal ATP-sensitive potassium channels(sarcKATP).Conclusion Pretreatment with EGb761 could protect against I/R-induced myocardial injury in rats,and the delayed cardioprotection of EGb761 may be related to increasing in NO production and opening of sarcKATP.