Selective biosorption of thorium (IV) from aqueous solutions by ginkgo leaf

Low-cost biosorbents (ginkgo leaf, osmanthus leaf, banyan leaf, magnolia leaf, holly leaf, walnut shell, and grapefruit peel) were evaluated in the simultaneous removal of La3+, Ce3+, Pr3+, Nd3+, Sm3+, Eu3+, Gd3+, Yb3+, Lu3+, UO22+, Th4+, Y3+, Co2+, Zn2+, Ni2+, and Sr2+ from aqueous solutions. In single metal systems, all adsorbents exhibited good to excellent adsorption capacities toward lanthanides and actinides. In a simulated multicomponent mixed solution study, higher selectivity and efficiency were observed for Th4+ over other metal cations, with ginkgo leaves providing the highest adsorptivity (81.2%) among the seven biosorbents. Through optimization studies, the selectivity of Th4+ biosorption on ginkgo leaf was found to be highly pH-dependent, with optimum Th4+ removal observed at pH 4. Th4+ adsorption was found to proceed rapidly with an equilibrium time of 120 min and conform to pseudo-second-order kinetics. The Langmuir isotherm model best described Th4+ biosorption, with a maximum monolayer adsorption capacity of 103.8 mg g-1. Thermodynamic calculations indicated that Th4+ biosorption was spontaneous and endothermic. Furthermore, the physical and chemical properties of the adsorbent were determined by scanning electron microscopy, Brunauer-Emmett-Teller, X-ray powder diffraction, and Fourier transform infrared analysis. The biosorption of Th from a real sample (monazite mineral) was studied and an efficiency of 90.4% was achieved from nitric acid at pH 4 using ginkgo leaves.

Mechanism for ginkgolic acid (15 : 1)-induced MDCK cell necrosis: Mitochondria and lysosomes damages and cell cycle arrest

Ginkgolic acids (GAs), primarily found in the leaves, nuts, and testa of ginkgo biloba, have been identified with suspected allergenic, genotoxic and cytotoxic properties. However, little information is available about GAs toxicity in kidneys and the underlying mechanism has not been thoroughly elucidated so far. Instead of GAs extract, the renal cytotoxicity of GA (15 : 1), which was isolated from the testa of Ginkgo biloba, was assessed in vitro by using MDCK cells. The action of GA (15 : 1) on cell viability was evaluated by the MTT and neutral red uptake assays. Compared with the control, the cytotoxicity of GA (15 : 1) on MDCK cells displayed a time- and dose-dependent manner, suggesting the cells mitochondria and lysosomes were damaged. It was confirmed that GA (15 : 1) resulted in the loss of cells mitochondrial trans-membrane potential (ΔΨm). In propidium iodide (PI) staining analysis, GA (15 : 1) induced cell cycle arrest at the G0/G1 and G2/M phases, influencing on the DNA synthesis and cell mitosis. Characteristics of necrotic cell death were observed in MDCK cells at the experimental conditions, as a result of DNA agarose gel electrophoresis and morphological observation of MDCK cells. In conclusion, these findings might provide useful information for a better understanding of the GA (15 : 1) induced renal toxicity.

Clinical and genomic safety of treatment with Ginkgo biloba L. leaf extract (IDN 5933/Ginkgoselect®Plus) in elderly: a randomised placebo-controlled clinical trial [GiBiEx]

BACKGROUND

Numerous health benefits have been attributed to the Ginkgo biloba leaf extract (GBLE), one of the most extensively used phytopharmaceutical drugs worldwide. Recently, concerns of the safety of the extract have been raised after a report from US National Toxicology Program (NTP) claimed high doses of GBLE increased liver and thyroid cancer incidence in mice and rats. A safety study has been designed to assess, in a population of elderly residents in nursing homes, clinical and genomic risks associated to GBLE treatment.

METHODS

GiBiEx is a multicentre randomized clinical trial, placebo controlled, double blinded, which compared subjects randomized to twice-daily doses of either 120-mg of IDN 5933 (also known as Ginkgoselect®Plus) or to placebo for a 6-months period. IDN 5933 is extracted from dried leaves and contains 24.3% flavone glycosides and 6.1% of terpene lactones (2.9% bilobalide, 1.38% ginkgolide A, 0.66% ginkgolide B, 1.12% ginkgolide C) as determined by HPLC. The study was completed by 47 subjects, 20 in the placebo group and 27 in the treatment group. Clinical (adverse clinical effect and liver injury) and genomic (micronucleus frequency, comet assay, c-myc, p53, and ctnnb1 expression profile in lymphocytes) endpoints were assessed at the start and at the end of the study.

RESULTS

No adverse clinical effects or increase of liver injury markers were reported in the treatment group. The frequency of micronuclei [Mean Ratio (MR) = 1.01, 95% Confidence Intervals (95% CI) 0.86-1.18), and DNA breaks (comet assay) (MR = 0.91; 95% CI 0.58-1.43), did not differ in the two study groups. No significant difference was found in the expression profile of the three genes investigated.

CONCLUSIONS

None of the markers investigated revealed a higher risk in the treatment group, supporting the safety of IDN 5933 at doses prescribed and for duration of six months.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03004508 , December 20, 2016. Trial retrospectively registered.

Preparation of Starch-Hard Carbon Spherules from Ginkgo Seeds and Their Phenol-Adsorption Characteristics

Carbon spherules from ginkgo seed starch were prepared through stabilization and carbonization processes. The ginkgo seed starch was first stabilized at 195 °C for 18 h, then carbonized at 500 °C for 2 h under an N₂ atmosphere. The characterization results confirmed that carbon spherules were in the size range of 10–20 μm. Experimental data were also evaluated to find out the kinetic characteristics of phenols on the carbon spherules during the adsorption process. Adsorption processes for phenol, p-nitrophenol and p-chlorophenol were found to follow the pseudo-first order kinetic model with R² values of 0.995, 0.997 and 0.998, while the rate constants k₁ = 0.014, 0.009 and 0.011 min⁻¹ showed that the adsorption is mainly controlled by adsorbate diffusion. The equilibrium data were analyzed with the Langmuir, Freundlich and Temkin–Pyzhev models and the best fit was observed with the Freundlich isotherm, suggesting the physical adsorption of phenols. From the thermodynamic functions, ∆G, ∆H, and ∆S were calculated, which showed that adsorption is more favorable at low temperature and is an exothermic process, and the adsorption of p-nitrophenol and p-chlorophenol were more advantageous than that of phenol.

Adsorption of Pb(II) and Cu(II) by Ginkgo-Leaf-Derived Biochar Produced under Various Carbonization Temperatures and Times

Ginkgo trees are common street trees in Korea, and the large amounts of leaves that fall onto the streets annually need to be cleaned and treated. Therefore, fallen gingko leaves have been used as a raw material to produce biochar for the removal of heavy metals from solutions. Gingko-leaf-derived biochar was produced under various carbonization temperatures and times. This study evaluated the physicochemical properties and adsorption characteristics of gingko-leaf-derived biochar samples produced under different carbonization conditions regarding Pb(II) and Cu(II). The biochar samples that were produced at 800 °C for 90 and 120 min contained the highest oxygen- and nitrogen-substituted carbons, which might contribute to a high metal-adsorption rate. The intensity of the phosphate bond was increased with the increasing of the carbonization temperature up to 800 °C and after 90 min of carbonization. The Pb(II) and Cu(II) adsorption capacities were the highest when the gingko-leaf-derived biochar was produced at 800 °C, and the removal rates were 99.2% and 34.2%, respectively. The highest removal rate was achieved when the intensity of the phosphate functional group in the biochar was the highest. Therefore, the gingko-leaf-derived biochar produced at 800 °C for 90 min can be used as an effective bio-adsorbent in the removal of metals from solutions.

Qualitative and Quantitative Analysis of Carbohydrate Modification on Glycoproteins from Seeds of Ginkgo biloba

Recent progress in the relationship between carbohydrate cross-reactive determinants (CCDs) and allergic response highlights the importance of carbohydrate moieties in the innate immune system. Previous research pointed out that the protein allergen in Ginkgo biloba seeds is glycosylated, and the oligosaccharides conjugated to these proteins might also contribute to the allergy. The aim of this study was to analyze carbohydrate moieties, especially N-linked glycans, of glycoproteins from Ginkgo seeds originating from different places for detailed structures, to enable further research on the role played by N-glycans in Ginkgo-caused allergy. Results of monosaccharide composition and immunoblotting assays indicated the existence of N-glycans. Detailed structural elucidation of the N-glycans was further carried out by means of hydrophilic interaction ultraperformance liquid chromatography (HILIC-UPLC) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). In total, 14 out of 16 structures detected by UPLC were confirmed by MALDI-TOF-MS and tandem mass spectrometry, among which complex-type N-glycans bearing Lewis A determinants and high-mannose-type N-glycans were identified from Ginkgo seeds for the first time. Precise quantification of N-glycans was performed by use of an external standard, and both the absolute amount of each N-glycan and the percentage of different types of N-glycan showed significant diversity among the samples without any pattern of geographic variation.

Ginkgo biloba extracts-loaded starch nano-spheres: Preparation, characterization, and in vitro release kinetics

Ginkgo as a promising edible material and herbal medicine has received much attention due to its abundant starch contents and functional ingredient ginkgo biloba extracts (GBEs). Many foreign scholars suggest that GBEs can effectively ameliorate the symptoms of mild memory impairment and Alzheimer's dementia. However, an insurmountable problem with application of the GBEs is its low bioavailability, which restricts its application in vivo. Considering the biocompatibility between GBEs and starch, we have prepared ginkgo and corn starch-based nano-carriers, and thereby loaded GBEs onto starch nano-spheres (SNPs) by nanoprecipitation. Compared with unloaded SNPs (201-250nm), the mean sizes of the monodispersed and spherical GBEs-loaded SNPs were 255-396nm. Moreover, the loading amounts of GBEs onto ginkgo, and corn SNPs were 0.661-1.045, and 0.560mg/mg, respectively. In addition, in artificial gastric and intestinal juices, the GBEs-loaded SNPs exhibited a better sustained release than free GBEs.

Effects of Six-Week Ginkgo biloba Supplementation on Aerobic Performance, Blood Pro/Antioxidant Balance, and Serum Brain-Derived Neurotrophic Factor in Physically Active Men

Extracts of Ginkgo biloba leaves, a natural source of flavonoids and polyphenolic compounds, are commonly used as therapeutic agents for the improvement of both cognitive and physiological performance. The present study was aimed to test the effects of a six-week supplementation with 160 mg/day of a standardized extract of Ginkgo biloba or a matching placebo on aerobic performance, blood antioxidant capacity, and brain-derived neurotrophic factor (BDNF) level in healthy, physically active young men, randomly allocated to two groups (n = 9 each). At baseline, as well as on the day following the treatment, the participants performed an incremental cycling test for the assessment of maximal oxygen uptake. Venous blood samples taken at rest, then immediately post-test and following 1 h of recovery, were analyzed for activities of antioxidant enzymes and plasma concentrations of non-enzymatic antioxidants, total phenolics, uric acid, lipid peroxidation products, ferric reducing ability of plasma (FRAP), and serum brain-derived neurotrophic factor (BDNF). Our results show that six weeks' supplementation with Ginkgo biloba extract in physically active young men may provide some marginal improvements in their endurance performance expressed as VO₂max and blood antioxidant capacity, as evidenced by specific biomarkers, and elicit somewhat better neuroprotection through increased exercise-induced production of BDNF.

Exceptionally high percentage of IPP synthesis by Ginkgo biloba IspH is mainly due to Phe residue in the active site

(E)-4-Hydroxy-3-methylbut-2-enyl diphosphate (HMBPP) reductase (IspH, HDR or LytB) is an Fe/S enzyme catalyzing the reductive dehydroxylation of HMBPP to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) in the last step of methylerythritol phosphate (MEP) pathway. The MEP pathway is known to produce 4-6:1 ratio of IPP and DMAPP mixture by the last enzyme, IspH. Plant IspH in plastids follows same catalytic mechanism as others, but GbIspH (Ginkgo biloba IspH) was reported to produce a mixture of IPP and DMAPP in a ratio of 16:1. Present catalytic mechanisms of IspH involve a common allyl anion intermediate, and the intramolecular proton transfer to the allyl moiety is considered as the key reaction step determining the product between IPP and DMAPP. The F212 residue in plant IspH was found as a potential amino acid residue that could mediate the proton transfer to the allyl anion intermediate before the product release. In this report, catalytic function of GbIspH F212 residue (H74 in E. coli), especially during the product formation in the active site, was studied by means of site-directed mutation. The product ratio of IPP/DMAPP was measured as 6.5 ± 0.1 for F212H GbIspH, and the value was close to the reported bacterial IspH having His residue on that specific position. Along with the other F212Y mutant, of which ratio was determined as 10.9 ± 0.1, the results strongly support that the Phe residue in plant IspH is the key amino acid residue that allows exclusive production of IPP in plant chloroplast.

[Simultaneous determination of eleven components in Ginkgo biloba leaves by high performance liquid chromatography method]

To study Ginkgo biloba leaves in different producing area, we establish an HPLC method for the simultaneously determination of seven flavonoids glycosides and four biflavonoids in G. biloba leaves. The analysis was performed on an Agilent ZORBAX SB-C₁₈ column(4.6 mm×250 mm, 5 μm) wich acetonitrile, and 0.4% phosphoric acid as mobile phase at flow rate of 1 mL•min⁻¹ in a gradient edution, and the detection was carried out at 254 nm.The calibration curves of the seven flavonoids glycosides and four biflavonoids had a good linearitiy with good recoveries. The established HPLC method is simple, rapid, accurate, reliable, and sensitive, and can be applied to the identification and quality control of G. biloba leaves.

Ginkgo biloba exocarp extracts induces apoptosis in Lewis lung cancer cells involving MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

A fruit of Ginkgo biloba L. is known as Ginkgo nuts. It is an edible traditional Chinese medicine, and could be used for the treatment of cancer thousands of years ago in China. The extracts prepared from the exocarp of Ginkgo biloba (Ginkgo biloba exocarp extracts, GBEE) has the effects of anti-cancer, immune promotion, anti-aging and etc.

AIM OF STUDY

To study the effects of GBEE inducing apoptosis in Lewis lung cancer (LLC) cells and the role of Mitogen-activated protein kinase(MAPK) signaling pathways in it.

MATERIALS AND METHODS

The LLC solid tumor model was established in C57BL/6J mice. The tumor-bearing mice were randomly divided into 5 groups. A normal control group without tumor cells was established additionally. There were 10 mice in each group, and they were dosed 24h after inoculation. The GBEE (50, 100, 200mg/kg b.w.) groups were dosed by intragastric gavage (i.g.). The mice in positive control group were intraperitoneal (i.p.) injected with cyclophosphamide (CPA) at a dose of 20mg/kg (b.w.). The model control group and the normal control group were both given normal saline (NS) by i.g.. All the groups were dosed at a volume of 0.1mL/10g (b.w.), once a day for 18d. The day after the last administration, the transplanted tumors was stripped and weighed, and the inhibition rate was calculated. In vitro experiments, MTT method was applied to detect the effects of GBEE on LLC cells and primary cultured mouse lung cells. Annexin V-FITC/PI method was used to detect the apoptosis rate of LLC cells. Rhodamine 123 method was used to detect the Mitochondrial transmembrane potential (MTP). Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the levels of Fas mRNA. Western Blot was used to detect the expression of Bax, Bcl-2, Cyt C, cleaved Caspase-3 and MAPK proteins in the corresponding parts of LLC cells.

RESULTS

GBEE (50-200mg/kg) inhibited the growth of LLC transplanted tumors with a dose-effect relationship. GBEE (5-160µg/mL) inhibited the proliferation of LLC cells in vitro with the half maximal inhibitory concentration (IC50) value of 162.43µg/mL, while it had no significant inhibitory effects on the primary cultured mouse lung cells. After GBEE (10, 20 and 40µg/mL) acted on the LLC cells, the apoptosis rate was increased and the MTP was decreased. The ratio of Bax/Bcl-2 was increased in the cells. Meanwhile, it also promoted the translocation of Bax/Bcl-2 in mitochondrial membrane and the release of Cyt C from mitochondria to cytosol. In addition, it up-regulated the cleaved-Caspase-3 protein expression. The mRNA levels of Fas and the protein levels of Fas, FasL and p-p38 in the cells were both increased. The levels of p-ERK1/2 and p-JNK1/2 protein were down-regulated but the p38, ERK1/2 and JNK1/2 were not significantly changed.

CONCLUSIONS

GBEE induces apoptosis in LLC cells via mitochondrial-mediated intrinsic pathway and death receptor-mediated extrinsic pathway, which may be closely relevant to the regulation of MAPK signaling pathways.

Ginkgolic Acid C 17:1, Derived from Ginkgo biloba Leaves, Suppresses Constitutive and Inducible STAT3 Activation through Induction of PTEN and SHP-1 Tyrosine Phosphatase

Ginkgolic acid C 17:1 (GAC 17:1) extracted from Ginkgo biloba leaves, has been previously reported to exhibit diverse antitumor effect(s) through modulation of several molecular targets in tumor cells, however the detailed mechanism(s) of its actions still remains to be elucidated. Signal transducer and activator of transcription 3 (STAT3) is an oncogenic transcription factor that regulates various critical functions involved in progression of diverse hematological malignancies, including multiple myeloma, therefore attenuating STAT3 activation may have a potential in cancer therapy. We determined the anti-tumor mechanism of GAC 17:1 with respect to its effect on STAT3 signaling pathway in multiple myeloma cell lines. We found that GAC 17:1 can inhibit constitutive activation of STAT3 through the abrogation of upstream JAK2, Src but not of JAK1 kinases in U266 cells and also found that GAC can suppress IL-6-induced STAT3 phosphorylation in MM.1S cells. Treatment of protein tyrosine phosphatase (PTP) inhibitor blocked suppression of STAT3 phosphorylation by GAC 17:1, thereby indicating a critical role for a PTP. We also demonstrate that GAC 17:1 can induce the substantial expression of PTEN and SHP-1 at both protein and mRNA level. Further, deletion of PTEN and SHP-1 genes by siRNA can repress the induction of PTEN and SHP-1, as well as abolished the inhibitory effect of drug on STAT3 phosphorylation. GAC 17:1 down-regulated the expression of STAT3 regulated gene products and induced apoptosis of tumor cells. Overall, GAC 17:1 was found to abrogate STAT3 signaling pathway and thus exert its anticancer effects against multiple myeloma cells.

Screening and Identifying Antioxidative Components in Ginkgo biloba Pollen by DPPH-HPLC-PAD Coupled with HPLC-ESI-MS2

The Ginkgo biloba is one of ancient trees that exists from billions of years ago, its leaf and nut are used as herbs and foods in China, while so far its pollen does not have any application except pollination. In order to evaluate the antioxidant activity of Ginkgo biloba pollen, and rapidly screen its antioxidative components, the 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, total flavonoid, total phenol, and proanthocyanidin of Ginkgo biloba pollen were determined and compared with those of Ginkgo biloba leaf and nut, and the off-line DPPH-HPLC-PAD and HPLC-ESI-MS² were applied for screening and identifying the antioxidant flavonoids in Ginkgo biloba pollen. The results showed that the DPPH scavenging ability of Ginkgo biloba pollen was much higher than Ginkgo biloba nut, but lower than Ginkgo biloba leaf, while the total content of flavonoid in Ginkgo biloba pollen was approximately 4.37 times higher than in Ginkgo biloba leaf. Further studies found that the major flavonol aglycone in Ginkgo biloba pollen was kaempferol, which accounted for 96.71% of the total aglycones (includes quercetin, kaempferol and isorhamnetin), and the main flavonoid components in Ginkgo biloba pollen were flavonoid glycosides. Finally, ten antioxidant peaks were screened and identified to be flavonoids (including kaempferol and nine flavonoid glycosides), so flavonoids were likely to be the main antioxidant components in GP, and among them, three novel kaempferol glycosides (peaks 1, 2, and 3) were found in Ginkgo biloba pollen for the first time, which had never been found in Ginkgo biloba.

Effects of Ginkgo biloba on dementia: An overview of systematic reviews

OBJECTIVE

To assess the cumulative evidence on the efficacy and effectiveness of Ginkgo biloba extract (GbE) in the treatment of dementia.

DESIGN

Overview of systematic reviews.

METHODS

PubMed/MEDLINE, EMBASE, Cochrane, and Google Scholar were searched in June 2016. Systematic reviews (SRs) of randomized controlled trials (RCTs) evaluating the effects of GbE on different outcomes in people with dementia or cognitive impairment were included. Methodological quality of the included SRs was assessed using the AMSTAR tool. The quality of evidence of the primary studies was assessed using GRADE.

RESULTS

Twelve SRs with meta-analyses met the eligibility criteria. The quality of the evidence reported in these SRs varies ranging from low to moderate level. Overall, the available evidence suggests that GbE has potentially beneficial effects over placebo on cognitive performance, activities of daily living, and clinical global impression in the treatment of dementia at doses greater than 200mg/day (usually 240mg/day) administrated for 22 weeks or longer, and that GbE appears to be safe for human consumption. No sufficient evidence supports the favorable effects of GbE administrated for less than 22 weeks. The available evidence consistently indicates that a dose less than 200mg/day of GbE may not be adequate to yield clinical relevant effects in the treatment of dementia.

CONCLUSIONS

GbE has potentially beneficial effects for people with dementia when it is administered at doses greater than 200mg/day for at least 5 months. Given the lower quality of the evidence, further rigorously-designed, multicenter-based, large-scale RCTs are warranted.

Molecular Cloning, Characterization, and Functional Analysis of Acetyl-CoA C-Acetyltransferase and Mevalonate Kinase Genes Involved in Terpene Trilactone Biosynthesis from Ginkgo biloba

Ginkgolides and bilobalide, collectively termed terpene trilactones (TTLs), are terpenoids that form the main active substance of Ginkgo biloba. Terpenoids in the mevalonate (MVA) biosynthetic pathway include acetyl-CoA C-acetyltransferase (AACT) and mevalonate kinase (MVK) as core enzymes. In this study, two full-length (cDNAs) encoding AACT (GbAACT, GenBank Accession No. KX904942) and MVK (GbMVK, GenBank Accession No. KX904944) were cloned from G. biloba. The deduced GbAACT and GbMVK proteins contain 404 and 396 amino acids with the corresponding open-reading frame (ORF) sizes of 1215 bp and 1194 bp, respectively. Tissue expression pattern analysis revealed that GbAACT was highly expressed in ginkgo fruits and leaves, and GbMVK was highly expressed in leaves and roots. The functional complementation of GbAACT in AACT-deficient Saccharomyces cerevisiae strain Δerg10 and GbMVK in MVK-deficient strain Δerg12 confirmed that GbAACT mediated the conversion of mevalonate acetyl-CoA to acetoacetyl-CoA and GbMVK mediated the conversion of mevalonate to mevalonate phosphate. This observation indicated that GbAACT and GbMVK are functional genes in the cytosolic mevalonate (MVA) biosynthesis pathway. After G. biloba seedlings were treated with methyl jasmonate and salicylic acid, the expression levels of GbAACT and GbMVK increased, and TTL production was enhanced. The cloning, characterization, expression and functional analysis of GbAACT and GbMVK will be helpful to understand more about the role of these two genes involved in TTL biosynthesis.

Effects of Ginkgo biloba extract on brain oxidative condition after cisplatin exposure

PURPOSE

The purpose of this study was to evaluate the efficacy of Ginkgo biloba extract (EGb 761) on oxidative events of brain in cisplatin-administrated rats.

METHODS

Rats were divided into four experimental groups: 1) control (n=6); 2) cisplatin (8 mg/kg, intraperitoneally one dose, n=6); 3) EGb 761 (100 mg/kg intraperitoneally for 15 days, n=6); and 4) cisplatin + EGb 761 (n=6). After drug administration, rats were sacrificed and brain tissues were removed. Nitric oxide (NO), malondialdehyde (MDA) and glutathione (GSH) levels were evaluated in brain tissues.

RESULTS

Single dose cisplatin administration significantly increased NO and GSH levels, but decreased MDA levels in brain tissue samples. EGb 761 treatment reversed the effects of cisplatin on NO and GSH levels, but did not affect the decreased MDA levels.

CONCLUSION

Results of the study indicate that oxidative stress can be an important pathogenetic mechanism of cisplatin-induced neurotoxicity. EGb 761, an standardized extract of G. biloba leaves that has antioxidant properties, may improve the oxidative stress-related neurological side effects of cisplatin.

Ginkgo biloba exocarp extracts inhibits angiogenesis and its effects on Wnt/β-catenin-VEGF signaling pathway in Lewis lung cancer

ETHNOPHARMACOLOGICAL RELEVANCE

A fruit of Ginkgo biloba L. also known as Ginkgo biloba, can be used for the treatment of cancer in Chinese traditional medicine. The scientific name of succulent skin, which is the episperm of Ginkgo nuts, is exocarp. Experiment shows that Ginkgo biloba exocarp extracts (GBEE) has the effects of immune promotion, cancer inhibition and etc.

AIM OF STUDY

Study on the activity of GBEE against Lewis lung cancer (LLC) angiogenesis and its partial molecular mechanism.

MATERIALS AND METHODS

The effect of GBEE on proliferation of LLC cells was detected by MTT method in vitro. The metastasis model of LLC was set up. The C57BL/6J mice were randomly separated into normal control, model control, positive control and GBEE (50, 100, 200mg/kg) treatment groups, n=10. The mice in normal group and model group were both intragastric gavage (i.g.) normal saline (NS) in a volume of 0.1mL/10g (b.w.), positive group were intraperitoneal (i.p.) injection cyclophosphamide (CPA) at a dose of 20mg/kg (b.w.) , the GBEE treatment groups were respectively i.g. GBEE 50, 100, and 200mg/kg (b.w.), once a day for 20d. After treatment, we calculated the tumor inhibition rate and anti-metastasis rate. The microvessel density (MVD) was measured by immunohistochemistry method in transplanted tumor. The expression levels of vascular en-dothelial growth factor (VEGF) and VEGFR2 mRNA or Wnt3a, β-catenin, VEGF, VEGFR2 and p-Akt/Akt protein expression were respectively tested by Quantitative Reverse transcription Polymerase chain reaction (qRT-PCR) or western blot in vitro and vivo.

RESULTS

GBEE suppressed the growth of LLC cells in a dose-dependent way at the dose of 5, 10, 20, 40, 80 and 160µg/mL in vitro. It can suppressed Wnt3a and β-catenin protein expression and the content of mRNA of VEGF and VEGFR2 in LLC cells significantly. In vivo, we discovered GBEE can retard the growth of LLC transplanted tumor in a dose-dependent way at the dose of 50, 100, 200mg/kg, suppressing tumor lung metastasis. The expression of CD34 was reduced, which means MVD was inhibited and so do β-catenin, VEGF, VEGFR2 and p-AKT/AKT protein expression and VEGF and VEGFR2 mRNA expression levels in LLC transplanted tumor of C57BL/6 mice.

CONCLUSIONS

GBEE played the effects of anti-tumor and anti-metastatic depending upon the inhibition of tumor angiogenesis, which may be closely relevant to its effect in blockage of Wnt /β-catenin-VEGF signaling pathway in LLC.

Mass spectrometric imaging of flavonoid glycosides and biflavonoids in Ginkgo biloba L

Ginkgo biloba L. is known to be rich in flavonoids and flavonoid glycosides. However, the distribution within specific plant organs (e.g. within leaves) is not known. By using HPLC-MS and MS/MS we have identified a number of previously known G. biloba flavonoid glycosides and biflavonoids from leaves. Namely, kaempferol, quercetin, isorhamnetin, myricetin, laricitrin/mearnsetin and apigenin glycosides were identified. Furthermore, biflavonoids like ginkgetin/isoginkgetin were also detected. The application of MALDI mass spectrometric imaging, enabled the compilation of concentration profiles of flavonoid glycosides and biflavonoids in G. biloba L. leaves. Both, flavonoid glycosides and biflavonoids show a distinct distribution in leaf thin sections of G. biloba L.

Determination of Multiresidue Pesticides in Botanical Dietary Supplements Using Gas Chromatography-Triple-Quadrupole Mass Spectrometry (GC-MS/MS)

A simplified sample preparation method in combination with gas chromatography-triple-quadrupole mass spectrometry (GC-MS/MS) analysis was developed and validated for the simultaneous determination of 227 pesticides in green tea, ginseng, gingko leaves, saw palmetto, spearmint, and black pepper samples. The botanical samples were hydrated with water and extracted with acetonitrile, magnesium sulfate, and sodium chloride. The acetonitrile extract was cleaned up using solid phase extraction with carbon-coated alumina/primary-secondary amine with or without C18. Recovery studies using matrix blanks fortified with pesticides at concentrations of 10, 25, 100, and 500 μg/kg resulted in average recoveries of 70-99% and relative standard deviation of 5-13% for all tested botanicals except for black pepper, for which lower recoveries of fortified pesticides were observed. Matrix-matched standard calibration curves revealed good linearity (r(2) > 0.99) across a wide concentration range (1-1000 μg/L). Nine commercially available tea and 23 ginseng samples were analyzed using this method. Results revealed 36 pesticides were detected in the 9 tea samples at concentrations of 2-3500 μg/kg and 61 pesticides were detected in the 23 ginseng samples at concentrations of 1-12500 μg/kg.

The effect of Bacillus coagulans-fermented and nonfermented Ginkgo biloba on the immunity status of broiler chickens

To evaluate and compare the effects of Bacillus coagulans-fermented Ginkgo biloba (FG) and nonfermented Ginkgo biloba (NFG) on the immunity status of broiler chickens, 180 1-d-old female Arbor Acres chicks were divided into 3 groups and fed either a basal diet, a basal diet supplemented with 0.3% NFG, or a basal diet supplemented with 0.3% FG. Blood samples were taken on the seventh (before vaccination), 14th, 21st, 28th and 35th day for the assessment of serum IL-18 and interferon γ (IFN-γ) levels by ELISA. In addition, Newcastle disease antibody titer analysis was made via hemagglutination and hemagglutination inhibition test methods. On d 35, 6 chickens from each group were sacrificed and the thymus, liver, spleen, small intestine (jejunum segment), cecum, and bursa of Fabricius from each chicken were removed for analysis. RNA was isolated for defensin expression detection by real-time PCR (q-PCR). The results showed that serum IL-18 and IFN-γ levels decreased after treatment with NFG and FG compared with untreated control chickens. The ND antibody titers did not differ significantly between the 3 groups on the seventh, 14th, 21st and 28th day; however, on the 35th day, the ND antibody titers of the NFG and FG chickens were both significantly higher than those of control group chickens. Defensin RNA expression levels were inhibited by NFG; however, they were induced by FG. In conclusion, fermentation of Ginkgo biloba with Bacillus coagulans can promote the beneficial effect of Gingko biloba on the immunity status of broiler chickens.

An antifungal protein from Ginkgo biloba binds actin and can trigger cell death

Ginkbilobin is a short antifungal protein that had been purified and cloned from the seeds of the living fossil Ginkgo biloba. Homologues of this protein can be detected in all seed plants and the heterosporic fern Selaginella and are conserved with respect to domain structures, peptide motifs, and specific cysteine signatures. To get insight into the cellular functions of these conserved motifs, we expressed green fluorescent protein fusions of full-length and truncated ginkbilobin in tobacco BY-2 cells. We show that the signal peptide confers efficient secretion of ginkbilobin. When this signal peptide is either cleaved or masked, ginkbilobin binds and visualizes the actin cytoskeleton. This actin-binding activity of ginkbilobin is mediated by a specific subdomain just downstream of the signal peptide, and this subdomain can also coassemble with actin in vitro. Upon stable overexpression of this domain, we observe a specific delay in premitotic nuclear positioning indicative of a reduced dynamicity of actin. To elucidate the cellular response to the binding of this subdomain to actin, we use chemical engineering based on synthetic peptides comprising different parts of the actin-binding subdomain conjugated with the cell-penetrating peptide BP100 and with rhodamine B as a fluorescent reporter. Binding of this synthetic construct to actin efficiently induces programmed cell death. We discuss these findings in terms of a working model, where ginkbilobin can activate actin-dependent cell death.

DECOCTION PROCESS OPTIMIZATION AND QUALITY EVALUATION OF YI-HUANG DECOCTION BY HPLC FINGERPRINT ANALYSIS

Yi Huang decoction (YHD) has been used as one of famous traditional formula because of its unique effectiveness against gynecological diseases. YHD is composed of five herbs, including the rootstock of Dioscoma opposita Thunb. (Dioscoreaceae), the kernel of Etayale ferx Salisb. (Nymphaeaceae), the bark of Phellodendron chinense Schneid. (Rutaceae), the seed of Plantago asiatica L. (Plantaginaceae), and the seed of Ginkgo biloba L. (Ginkgoaceae). To effectively control the quality, the processing method for YHD was optimized by means of single factor test as well as orthogonal test in this study. A completely validated method based on HPLC coupled with diode array detector was performed on a Kromasil C(18) column at 30° with mobile phase of 0.1% aqueous phosphoric acid and acetonitrile. As a result, HPLC fingerprint on the basis of the chromatographic data from 32 batches of samples was obtained, which contained 44 common peaks. Among these common peaks, 6 peaks were identified as geniposidic acid, berberine hydrochloride, palmatine hydrochloride, phellodendrine chloride, magnoflorine, and verbascoside, respectively, based on their retention time relative to the standards. Meanwhile, the contents of these 6 compounds were also simultaneously examined. In sum, this study offered valuable information for the proper processing and quality control for YHD.

Effects of Ginkgo biloba on plasma oxidant injury induced by bleomycin in rats

Bleomycin is an anti-neoplastic agent and its clinical usage is limited by its toxicity, which is mostly induced by oxygen radicals. The aim of this study was to investigate the effect of Ginkgo biloba on plasma indices of oxidants induced by bleomycin in rats.

Male Sprague-Dawley rats were divided into five groups: none medicated or 0.9% NaCl injected or only Ginkgo biloba (orally, 100 mg/kg per day for 14 days) or only a single dose of bleomycin (intratracheal, 2.5 U/kg) or Gingko biloba and bleomycin-treated groups. After 14 days, blood was taken before the rats were sacrificed. The plasma was removed and stored at −85°C until the study day. Plasma superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and xanthine oxidase (XO) enzyme activities with malondialdehyde and nitric oxide (NO) levels were studied.

The levels of malondialdehyde and NO with activity of XO were higher in plasma of bleomycin group than the other groups (P B/0.05). The activities of SOD and GSH-Px were increased in the bleomycin plus Gingko biloba group in comparison with the bleomycin group (P B/0.05). There was a positive correlation between malondialdehyde and NO levels in the bleomycin group (r-/0.859, P B/0.05). There were positive correlations between SOD and GSH-Px activities (r-/0.760, P B/0.05) and between XO activity and malondialdehyde level (r-/0.822, P B/0.05) in the bleomycin plus Gingko biloba group.

In conclusion, it was thought that bleomycin induced oxidative stress can be prevented by Gingko biloba treatment via high anti-oxidant enzyme activity together with decreased radical production from XO.

[Treatment of Early Diabetic Retinopathy by Liuwei Dihuang Pill Combined Ginkao Leaf Tablet]

OBJECTIVE

To observe the prevention and clinical efficacy of combination of Liuwei Dihuang Pill (LDP) and Ginkgo Leaf Tablet (GLT) for early diabetic retinopathy (DR).

METHODS

Using randomized, double-blind, double simulation, parallel controlled clinical trial, 140 type 2 diabetes mellitus (T2DM) outpatients were recruited and assigned to the treatment group and the control group, 70 in each group. All patients received basic Western medicine treatment (such as blood glucose and pressure control). Patients in the treatment group took LDP (8 pills each time, 3 times per day) and GLT (19.2 mg each time, 3 times per day), while those in the control group took LDP placebos and GLT placebos. All treatment lasted for 24 consecutive months. All subjects were followed-up every month. The general clinical data as sex, age, and metabolic data such as blood glucose, blood pressure, blood lipid, and DR prevalence rate were collected and statistically analyzed.

RESULTS

There was no significant difference in levels of blood glucose, blood pressure, or blood lipid between the two groups (P > 0.05). After treatment the DR incidence rate was significantly lower in the treatment group than in the control group [3.1% (2/64) vs 18.6% (11/59), P < 0.05)]. Meanwhile, the DR prevalence rate of the treatment group was also significantly lower than that of the control group [6.3% (4/64) vs 20.0% (13/59), P < 0.05].

CONCLUSION

Combination of LDP and GLT could effectively prevent and treat the development of DR in T2DM patients.

Targeted metabolomic profiling of cardioprotective effect of Ginkgo biloba L. extract on myocardial ischemia in rats

BACKGROUND

Myocardial ischemia (MI) is one of the highest mortality diseases in the world. It is closely associated with metabolism disorders of endogenous substances. Ginkgo biloba L. extract (GBE) is a popular herbal medicine used for prevention and therapy of MI. But its regulation effect on the metabolism disorders caused by MI remains currently unknown.

PURPOSE

Our metabolomic profiling study provided insight into endogenous metabolic disorders of MI and cardioprotective mechanisms of GBE.

STUDY DESIGN

The rats were preventive administrated of GBE (200mg/kg, i.g.) for 4 weeks and then subcutaneous injected of isoproterenol to establish MI model. Heart marker enzymes and histopathological examination were adopted to evaluate MI model and effect of GBE. On this base, endogenous metabolites in rat plasma and heart were well profiled using the developed targeted metabolomic profiling platform to comprehensively analyze metabolic pathways and find biomarkers.

METHODS

A targeted metabolomic profiling platform was developed and only 100μl biological sample was used to quantify 808 metabolites covering the core network of lipid, energy, amino acid and nucleotide metabolism. Then using this platform, endogenous metabolites of rats undergoing MI model and GBE pre-treatment were well profiled. Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to discriminate between groups and find biomarkers.

RESULTS

The metabolomic profiles of MI model rats pre-protected by GBE were significantly different from those of unprotected. 47 metabolites were found as potential biomarkers and indicated MI would lead to disturbed metabolism due to inflammation, oxidative stress and structural damage; while GBE could effectively restore fatty acid, sphingolipid, phosphoglyceride, glyceride, amino acid and energy metabolism, closely related to its antioxidant, PAF antagonist and hypolipidemic properties.

CONCLUSION

The cardioprotective effect of GBE can be achieved through the comprehensive regulation of multiple metabolic pathways.