Diterpene Ginkgolides Exert an Antidepressant Effect Through the NT3-TrkA and Ras-MAPK Pathways.

BACKGROUND: Depression is a highly prevalent mental illness that severely impacts the quality of life of affected individuals. Our recent studies demonstrated that diterpene ginkgolides (DG) have antidepressant effects in mice. However, the underlying molecular mechanisms remained much unclear. METHODS: In this study, we assessed the antidepressant effects of chronic DG therapy in rats by evaluating depression-related behaviors, we also examined potential side effects using biochemical indicators. Furthermore, we performed an in-depth molecular network analysis of gene-protein-metabolite interactions on the basis of metabolomics. RESULTS: Chronic DG treatment significantly ameliorated the depressive-like behavioral phenotype. Furthermore, the neurotrophin signaling-related NT3-TrkA and Ras-MAPK pathways may play an important role in the antidepressant effect of DG in the hippocampus. CONCLUSION: These findings provide novel insight into the mechanisms underlying the antidepressant action of DG, and should help advance the development of new therapeutic strategies for depression.

Ginkgolide B enhances gemcitabine sensitivity in pancreatic cancer cell lines via inhibiting PAFR/NF-кB pathway.

Gemcitabine resistance will occur by time after the initial response in pancreatic cancer. Ginkgolide B (GB), a major terpene lactone component of Ginkgo biloba leaves, is a highly selective and competitive inhibitor for platelet-activating factor (PAF) receptor. In the present study, we evaluated the effect of GB on gemcitabine sensitivity in pancreatic cancer cell lines in vitro and in vivo. Cell viability assay, flow cytometry, dual luciferase reporter assay and tumor xenograft model were used to evaluate cell proliferation, apoptosis, nuclear factor kappa b (NF-кB) activity in vitro and tumor growth in vivo. Western blot, immunohistochemistry (IHC) and immunofluorescence were used to shown different protein expression levels. We found the half maximal inhibitory concentration (IC50) of gemcitabine was significantly downregulated by GB in a dose-dependent manner. Furthermore, GB could suppress cell proliferation, increase cell apoptosis and repress tumor growth when combined with gemcitabine, but had no effect when treated alone. Gemcitabine could upregulate PAFR and phosphorylated NF-кB/p65 expression, and increase NF-кB activity, but this was largely suppressed in combination with GB. GB could suppress PAFR expression in a dose-dependent manner. Knockout of PAFR significantly decreased phosphorylated NF-кB/p65 expression, inhibited NF-кB activity, increased gemcitabine sensitivity and cell apoptosis. Besides, GB had no influence on gemcitabine IC50 in IκBα-SR stably expressed BxPC-3 and CAPAN1. Our results suggested that GB could enhance gemcitabine sensitivity in pancreatic cancer cell lines by suppressing PAFR/NF-кB pathway. Thus GB may have therapeutic potential when used in combination with gemcitabine in pancreatic cancer.

Comparing the role of Ginkgolide B and Ginkgolide K on cultured astrocytes exposed to oxygen­glucose deprivation.

Ginkgolide B (GB) and ginkgolide K (GK) are two main active monomers of ginkgolides that present a unique group of diterpenes found naturally in the leaves of the Ginkgo biloba tree. Astrocytes are the most abundant cell type within the central nervous system (CNS) and serve essential roles in maintaining healthy brain function. The present study compared the biological effects of GB and GK on astrocytes exposed to oxygen­glucose deprivation (OGD). The results demonstrated that GB and GK exhibit many different actions. The level of the platelet­activating factor (PAF) was elevated on astrocytes exposed to OGD, and inhibited by GB and GK treatment. Although GB and GK inhibited the expression of p­NF­κB/p65, GK exerted stronger anti­inflammatory and antioxidant effects on astrocytes exposed to OGD than GB by inhibiting interleukin (IL)­6 and tumor necrosis factor­α, and inducing IL­10 and the nuclear factor­erythroid 2­related factor 2/HO­1 signaling pathway. When compared with GB treatment, GK treatment maintained high levels of phosphoinositide 3­kinase/phosphorylated­protein kinase B expression, and induced a marked upregulation of Wnt family member 1 and brain derived neurotrophic factor, indicating that GK, as a natural plant compound, may have more attractive prospects for clinical application in the treatment of neurological disorders than GB.

Diterpene ginkgolides meglumine injection protects against paraquat-induced lung injury and pulmonary fibrosis in rats.

In this study, we aimed to investigate the effects of diterpene ginkgolides meglumine injection (DGMI) on paraquat (PQ)-induced lung injury and pulmonary fibrosis in rats. Male SD rats were challenged by PQ (20?mg/kg, i.p.) with or without either DGMI (1.25, 2.5, 5?mg/kg, i.p.) or Edaravone (EDA, 6?mg/kg, i.p.) posttreatment 2?h after PQ administration. Lung tissues were removed for biochemical analyses and pathological examinations on day 1, day 3, day 7, day 14 and day 21. Results showed that the administration of DGMI significantly increased the survival of PQ-challenged rats. At the same time, DGMI reversed the increase of Malondialdehyde (MDA) level and the decrease of Super Oxide Dismutase (SOD) level in lung tissues. Moreover, lung to body weight ratio, Interleukin-1beta (IL-1?), Interleukin-6 (IL-6) and Tumor necrosis factor-alpha (TNF-?) levels in lung tissues were reduced compared with the model group. H&E and Masson staining revealed that DGMI (5?mg/kg) alleviated histological injury and pulmonary fibrosis, and EDA (6?mg/kg) exerted approximate effects. Immunohistochemistry staining presented that the benefit effects of DGMI were associated with its ability to activate Akt-Nrf-2 pathway. In conclusion, these results suggest that DGMI possesses potential role in future therapies for PQ-induced lung injury and pulmonary fibrosis.

Ginkgolide A ameliorates non-alcoholic fatty liver diseases on high fat diet mice.

Non-alcoholic fatty liver disease (NAFLD) is one of the most common diseases worldwide and has continuously increased. NAFLD refers to a spectrum of diseases ranging from fatty liver to steatohepatitis, cirrhosis, and even to hepatocyte carcinoma. Excessive fatty acid enters the cell and the mitochondria undergo stress and unremoved ROS can trigger a form of cell apoptosis known as 'lipoapoptosis'. NASH arises from damaged liver hepatocytes due to lipotoxicity. NASH not only involves lipid accumulation and apoptosis but also inflammation. Ginkgo biloba has been tested clinical trials as a traditional medicine for asthma, bronchitis and cardiovascular disease. The effects of Ginkgolide A (GA), derived from the ginkgo biloba leaf, are still unknown in NAFLD. To determine the protective effects of GA in NAFLD, we examined the fatty liver disease condition in the non-esterified fatty acid (NEFA)-induced HepG2 cell line and in a high fat diet mouse model. The findings of this study suggest that GA is non-toxic at high concentrations in hepatocytes. Moreover, GA was found to inhibit cellular lipogenesis and lipid accumulation by causing mitochondrial oxidative stress. GA showed hepatoprotective efficacy by inducing cellular lipoapoptosis and by inhibiting cellular inflammation. The results demonstrated that GA may be feasible as a therapeutic agent for NAFLD patients.

Protective effects of bilobalide against ethanol-induced gastric ulcer in vivo/vitro.

Bilobalide (BI) has been widely known as a unique constituent extracted from Ginkgo biloba. The aim of the current study was to reveal the potential efficacy as well as the underlying mechanism of the action of BI on ethanol-induced lesion in gastric mucosa in vivo/vitro. Ethanol (0.2ml/kg) was applied to induce gastric ulcer mice model. Our results indicated that treatment with BI markedly decreased the levels of interleukin-6 (IL-6), IL-1ß and tumor necrosis factor-α (TNF-α) in vivo. Additionally, BI intervation exhibited elevated myeloperoxidase (MPO) level in stomach, increased superoxide dismutase (SOD) activity and decreased malonaldehyde (MDA) content in serum and stomach when compared with those of the model group. It could be also observed that inhibited MAPK/NF-κB pathway expressions occurred after BI treatment both in vivo and in vitro. Taken together, BI exerted a gastro-protective effect against gastric ulceration, which was presumed to be associated with MAPK/NF-κB pathway.

A novel oil-body nanoemulsion formulation of ginkgolide B: pharmacokinetics study and in vivo pharmacodynamics evaluations.

The goal of this study was to develop a novel oil-body nanoemulsion (ONE) for Ginkgolide B (GB) and to conduct pharmacokinetics and pharmacodynamics evaluations. GB-ONE was prepared by O/O emulsion method. The differences in pharmacokinetics parameters and tissue distribution of rats after oral administrated with GB-ONE were investigated by liquid chromatography-tandem mass spectrometry. Changes in the ethological and pathological characterizations of the Alzheimer's disease rats after treated with GB-ONE were evaluated by Morris water maze (MWM) and pathological section, respectively. Furthermore, choline acetyltransferase (ChAT) and acetylcholinesterase (AchE) activity in hippocampus was analyzed by spectrophotometric method. The results indicated that the AUC of GB in rats' plasma was significantly improved after incorporated into ONE, and GB-ONE was significantly targeted into brain. In MWM experiment, memory improvement of rats with cognition impaired was confirmed after administrated with GB-ONE. Furthermore, GB-ONE significantly inhibited AchE activity and enhanced the activity of ChAT in the hippocampus. The overall results implicated that the novel ONE was effective for improving the drawbacks of GB and showed great potential for clinical application.

Ginkgo May Sensitize Ovarian Cancer Cells to Cisplatin: Antiproliferative and Apoptosis-Inducing Effects of Ginkgolide B on Ovarian Cancer Cells.

Ginkgolide B (GB), the primary active component ofGinkgo bilobaextracts, may have antitumor properties. The objective of this study was to determine the effects and possible mechanisms of GB in ovarian cancer cells. In this study, human ovarian cancer cell lines (SKOV3 and CAOV3) were treated with different concentrations of GB alone or in combination with Cis-diaminodichloroplatinum (CDDP). An MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was performed to determine cell viability. The apoptosis rates of cells were measured by flow cytometric analysis. The expression of apoptosis-associated and proliferation-associated proteins was detected by Western blot. The cytotoxicity of GB was analyzed using a lactate dehydrogenase assay. Treatment with 100 µM GB for 3 days significantly inhibited SKOV3 and CAOV3 cell proliferation by 57.3% and 63.1% compared with control cells, respectively, as determined by MTT assay. Similarly, the apoptotic cell population was increased when treated with GB in a dose-dependent manner both in SKOV3 and CAOV3 cells. These effects were characterized by the upregulation of p21, p27, cleaved capase-3, and cleaved caspase-8 and downregulation of cyclin D1. In addition, a combined treatment of low concentrations of GB and CDDP showed an additive effect on the inhibition of SKOV3 cell proliferation. Furthermore, GB had significantly less cytotoxicity than CDDP in normal human ovarian surface epithelial cells. This study suggests that GB can be proposed as an effective antiproliferative and apoptosis-inducing agent with interesting translational application in ovarian cancers, used in addition to conventional chemotherapy.

Mitochondria protection with ginkgolide B-loaded polymeric nanocapsules prevents diethylnitrosamine-induced hepatocarcinoma in rats.

AIM: Hepatocellular carcinoma (HCC) has no successful pharmacotherapeutic remedy. The aim of this study was to ascertain whether ginkgolide B (GB)-loaded polymeric nanocapsules can prevent diethylnitrosamine (DEN)-induced HCC in rats. MATERIALS & METHODS: GB was fabricated in two types of nanocapsules of which one was polyethylene glycol coated (N1GB) and the other was uncoated (N2GB). These nanocapsules were orally gavaged during DEN-induced HCC development in rats. RESULTS: Nanocapsulation of GB enabled aqueous suspension and slow time-dependent release of the compound. Anticarcinogenic potential of N2GB was reflected by its ability in the management of DEN-induced reactive oxygen species generation, mitochondrial dysfunction, p53, NF-κB, inducible nitric oxide synthase, COX-2 and VEGF expressions, and induction of apoptosis in cancer cells in the rat liver. CONCLUSION: Positive zeta-potential on N2GB surface might have offered higher hepatic accumulation of GB, especially at the electron-dense organelle mitochondria. Mitochondria protection against DEN-induced oxidative damage ensured HCC prevention.

Ginkgolide B reduces atherogenesis and vascular inflammation in ApoE(-/-) mice.

AIMS: To investigate whether ginkgolide B (a platelet-activating factor inhibitor) affects vascular inflammation in atherosclerosis-prone apolipoprotein E-deficient (ApoE(-/-)) mice. METHODS AND RESULTS: Human platelets were used to evaluate the effects of ginkgolide B on platelet aggregation and signal transduction. Ginkgolide B attenuated platelet aggregation and inhibited phosphatidylinositol 3 kinase (PI3K) activation and Akt phosphorylation in thrombin- and collagen-activated platelets. ApoE(-/-) mice were administered a high-cholesterol diet for 8 weeks. Plasma platelet factor 4 (PF4) and RANTES (regulated upon activation, normal T-cell expressed, and secreted protein) were then measured using an enzyme-linked immunosorbent assay. Scanning electron microscopy and immunohistochemistry were used to determine atherosclerotic lesions. Ginkgolide B decreased plasma PF4 and RANTES levels in ApoE(-/-) mice. Scanning electron microscopic examination showed that ginkgolide B reduced aortic plaque in ApoE(-/-) mice. Immunohistochemistry analysis demonstrated that ginkgolide B diminished P-selectin, PF4, RANTES, and CD40L expression in aortic plaque in ApoE(-/-) mice. Moreover, ginkgolide B suppressed macrophage and vascular cell adhesion protein 1 (VCAM-1) expression in aorta lesions in ApoE(-/-) mice. Similar effects were observed in aspirin-treated ApoE(-/-) mice. CONCLUSION: Ginkgolide B significantly reduced atherosclerotic lesions and P-selectin, PF4, RANTES, and CD40L expression in aortic plaque in ApoE-/- mice. The efficacy of ginkgolide B was similar to aspirin. These results provide direct evidence that ginkgolide B inhibits atherosclerosis, which may be associated with inhibition of the PI3K/Akt pathway in activated platelets.

Co-encapsulation and sustained-release of four components in ginkgo terpenes from injectable PELGE nanoparticles.

It is difficult to develop injectable sustained delivery systems for herbal medicines because of their composition complexity. Encapsulating various compounds with different physiochemical properties and achieving their synchronized and sustained release seem too hard to realize. In this paper, an injectable nanoparticulate system based on an mPEG-PLGA-mPEG (PELGE) platform was prepared for co-encapsulation and sustained release of four active components (ginkgolides A, B, C and bilobalide) in Ginkgo biloba extract. Different carriers were screened by macrophage uptake experiment for their ability to be long-circulation. Drug loaded nanoparticles were prepared with 10% PEG(2000) modified PLGA by a co-precipitation method. The encapsulation efficiency of the total ginkgo terpenes (GT) in the optimal formulation was 78.84±2.06% with a loading dose of 11.90±0.31mg/150mg PELGE. The particles exhibited a spherical shape with a mean diameter of 123.3±44.0nm and zeta potential of -30.86±2.49mV. Sustained and synchronized release of the four components from PELGE nanoparticles was observed both in vitro and in vivo, which was mainly contributed to the long circulation of PEGylated nanoparticles and the slow degradation of PLGA. The half-life time of the four terpenoid compounds were also significantly improved by incorporation into PELGE nanoparticles. The results indicate that a PELGE nanoparticle is a promising carrier system for sustained and synchronized release of herbal medicines containing multiple components.

Ginkgolide B reduces neuronal cell apoptosis in the hemorrhagic rat brain: possible involvement of Toll-like receptor 4/nuclear factor-kappa B pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginkgolide B (GB) is one of the ginkgolides that have been isolated from leaves and root bark of the Chinese tree Ginkgo biloba L. (Ginkgoaceae), and is a specific and potent antagonist of platelet activating factor. There is a large body of data showing that GB possesses a markedly neuroprotective property against ischemia-induced impairment in vivo and in vitro. Recently it has been found that GB can inhibit the inflammation in the rat brain tissues with ischemia/reperfusion injury and in the astrocytes treated with lipopolysaccharide, as well as protect neurons against beta-amyloid 25-35 and ischemia-induced apoptosis. However, there have been few reports on the influence of GB on intracerebral hemorrhage (ICH). This study was to investigate the effects of intraperitoneal GB on neuronal cell apoptosis, inflammatory cytokines and Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway after ICH. MATERIALS AND METHODS: Wistar rats obtained an intraperitoneal injection of 5, 10 and 20mg/kg GB after ICH once a day till day 5. Rats were sacrificed by decapitation at hour 2, 6 and 12, as well as day 1, 2, 3 and 5 after ICH. Gene expressions of TLR-4 and NF-κB, concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1ß) and interleukin-6 (IL-6) as well as number of apoptotic neuronal cells in hemorrhagic rat brain tissues were determined. RESULTS: The administration of 10 and 20mg/kg GB could significantly suppress gene expressions of TLR-4 and NF-κB, lessen concentrations of TNF-α, IL-1ß and IL-6 as well as reduce number of apoptotic neuronal cells in hemorrhagic rat brain tissues by Least-significant Difference test (P<0.05), but the administration of 5mg/kg GB not (P>0.05). However, a clear concentration-response relationship was not found. CONCLUSIONS: GB may inhibit TLR4/NF-κB-dependent inflammatory responses, and furthermore lessen neuronal cell apoptosis after ICH, which may support the use of G. biloba extracts for the treatment of ICH.

Therapeutic time window for treatment of focal cerebral ischemia reperfusion injury with XQ-1h in rats.

Pervious experimental studies have shown that XQ-1h has beneficial neuroprotective effect in the cerebral ischemia reperfusion injury. However, the therapeutic time window for treatment of focal cerebral ischemia reperfusion injury with XQ-1h is not clear. Under chloral hydrate anesthesia, transient focal cerebral ischemia was induced in rats by 2h of middle cerebral artery occlusion (MCAO), followed by 24h of reperfusion. Saline as vehicle or XQ-1h at the doses of 31.2, 15.6 and 7.8 mg/kg i.v. was administered at 0.5, 1, 2, 3h after induction of ischemia. Subsequently, 24h after MCAO brain edema, infarct volume, neurological deficits and cerebral blood flow were evaluated. Administrations of XQ-1h at the doses of 31.2mg/kg at 0.5, 1, and 2h after reperfusion of MCAO significantly reduced infarct rate (%) by 75.6% (5.2 ± 1.7), 66.2% (7.2 ± 1.9), and 47.9% (11.1 ± 1.2), respectively. XQ-1h (31.2mg/kg) treatment, 0.5, 1, and 2h after reperfusion produced significant improvement in neurological score compared to vehicle-treated group (P<0.01). Administrations of XQ-1h at the doses of 31.2mg/kg and 15.6 mg/kg at 0.5, 1, and 2h after reperfusion of MCAO significantly increased cerebral blood flow (mv) by 16.9 ± 1.9, 11.7 ± 1.3, 9.5 ± 1.0, respectively (P<0.01). In conclusion the therapeutic time window of XQ-1h for cerebral ischemia reperfusion injury is within 2h. Interestingly, we also discovered that the therapeutic time window of XQ-1h is deeply related with the activity of scavenging oxidative stress products. Further studies need to be conducted more drug combination therapy programs in order to assess the potential clinical application of XQ-1h.

[Effects of Ginkgolide B on inflammation induced by cerebral ischemia-reperfusion in rats].

OBJECTIVE: To investigate the protective effects of Ginkgolide B on inflammation induced by cerebral ischemia-reperfusion in rats. METHODS: Rats were pretreated with Ginkgolide B at the dose of 2. 5, 5, 10 mg/kg for 3 days and then subjected to cerebral ischemia/reperfusion induced by a middle cerebral artery occlusion (MCAO). The infarct volume and the neurological deficit were determined by the method of TTC (2,3,5-triphenylterazolium chloride) staining and Longa's score. The permeability of blood-brain barrier (BBB) was evaluated by measurement of the evans blue (EB) content in the brain with spectrophotometer. The content of interleukin-1beta, interleukin-6 (IL-6, IL-1beta) in serum and tumor necrosis factor-alpha (TNF-alpha), The content of E-selectin and ICAM 1 in brain were determined by radio-immunoassay and ELISA assay. RESULTS: Ginkgolide B reduced infarct volume, ameliorated the neurological deficit and the permeability of BBB, the content of IL-6, IL-1beta in serum and TNF-alpha, expressions of E-selectin and ICAM 1 in brain tissue also were significantly decreased. CONCLUSION: Ginkgolide B has protective effects on cerebral injury by inhibiting the inflammation induced by ischemia/reperfusion injury.

[Effect of ginkgolide B on the production of NO, IL-6 and RANTES from astrocytes].

This study is to explore the effect of ginkgolide B (BN52021) on the production of nitric oxide (NO), interleukin (IL)-6 and regulated upon activation normal T cell expressed and secreted (RANTES) from astrocytes induced by stimulators. Primary cultured rat astrocytes were stimulated with lipopolysaccharides (LPS), the production of NO was assayed using Griess reaction; U251 cells were stimulated with IL-1 beta, the contents of IL-6 and RANTES in the supernatant were measured using ELISA. The mRNA expressions of IL-6 and RANTES were detected using RT-PCR. LPS (10 ng mL(-1) to 10 microg mL(-1)) could stimulate rat astrocytes to produce NO in a dose-dependent manner. Ginkgolide B at the concentrations of 0.1-10 micromol L(-1) were shown to decrease NO production significantly. IL-1 beta could induce the mRNA expression and protein secretion of IL-6 from U251 cells, as well as RANTES. Ginkgolide B at concentrations of 0.1-10 micromol L(-1) were shown to inhibit RANTES secretion, and to inhibit mRNA expression of IL-6 and RANTES at concentration of 10 micromol L(-1). Ginkgolide B has inhibitory effect on the production of NO, IL-6 and RANTES from astrocytes treated with inflammatory stimulators.