Ginkgo biloba Extracts: A Review of the Pharmacokinetics of the Active Ingredients

Ginkgo biloba Extract EGb 761 Improves Vestibular Compensation and Modulates Cerebral Vestibular Networks in the Rat

Unilateral inner ear damage is followed by behavioral recovery due to central vestibular compensation. The dose-dependent therapeutic effect of Ginkgo biloba extract EGb 761 on vestibular compensation was investigated by behavioral testing and serial cerebral [¹⁸F]-Fluoro-desoxyglucose ([¹⁸F]-FDG)-μPET in a rat model of unilateral labyrinthectomy (UL). Five groups of 8 animals each were treated with EGb 761-supplemented food at doses of 75, 37.5 or 18.75 mg/kg body weight 6 weeks prior and 15 days post UL (groups A,B,C), control food prior and EGb 761-supplemented food (75 mg/kg) for 15 days post UL (group D), or control food throughout (group E). Plasma levels of EGb 761 components bilobalide, ginkgolide A and B were analyzed prior and 15 days post UL. Behavioral testing included clinical scoring of nystagmus, postural asymmetry, head roll tilt, body rotation during sensory perturbation and instrumental registration of mobility in an open field before and 1, 2, 3, 5, 7, 15 days after UL. Whole-brain [¹⁸F]-FDG-μPET was recorded before and 1, 3, 7, 15 days after UL. The EGb 761 group A (75 mg/kg prior/post UL) showed a significant reduction of nystagmus scores (day 3 post UL), of postural asymmetry (1, 3, 7 days post UL), and an increased mobility in the open field (day 7 post UL) as compared to controls (group E). Application of EGb 761 at doses of 37.5 and 18.75 mg/kg prior/post UL (groups B,C) resulted in faster recovery of postural asymmetry, but did not influence mobility relative to controls. Locomotor velocity increased with higher plasma levels of ginkgolide A and B. [¹⁸F]-FDG-μPET revealed a significant decrease of the regional cerebral glucose metabolism (rCGM) in the vestibular nuclei and cerebellum and an increase in the hippocampal formation with higher plasma levels of ginkgolides and bilobalide 1 and 3 days post UL. Decrease of rCGM in the vestibular nucleus area and increase in the hippocampal formation with higher plasma levels persisted until day 15 post UL. In conclusion, Ginkgo biloba extract EGb 761 improves vestibulo-ocular motor, vestibulo-spinal compensation, and mobility after UL. This rat study supports the translational approach to investigate EGb 761 at higher dosages for acceleration of vestibular compensation in acute vestibular loss.

Antioxidant and antigenotoxic activities of Ginkgo biloba L. leaf extract are retained after in vitro gastrointestinal digestive conditions

PURPOSE

The recognized biological properties of Ginkgo biloba extracts potentiate their utilization as an ingredient for functional foods. However, the digestive conditions can affect the chemical composition of the extracts and consequently their biological properties, which can lead to food safety problems. Thus, the impact of in vitro-simulated upper gastrointestinal tract digestion on the chemical composition and bioactivity of Ginkgo biloba leaf extract (GBE) was evaluated.

METHODS

Physicochemical conditions of human digestion were simulated in vitro, and its impact on the chemical composition of GBE was investigated by electrospray ionization-mass spectrometry. The persistence of bioactivity was investigated by subjecting GBE and the in vitro digested extract (DGBE) to the same methodology. Antioxidant properties were assessed using 2',7'-dichlorofluorescein diacetate to measure the intracellular oxidation of Schizosaccharomyces pombe cells pre-incubated with GBE or DGBE and exposed to H₂O₂. Antigenotoxicity was tested by comet assay in HT-29 colon cancer cells pre-incubated with GBE or DGBE and challenged with H₂O₂.

RESULTS

The chemical analysis revealed a considerable change in chemical composition upon digestion. Pre-incubation with GBE or DGBE attenuated the H₂O₂-imposed intracellular oxidation in wild-type S. pombe cells, unlike the oxidative stress response-affected mutants sty1 and pap1, and decreased H₂O₂-induced DNA damage in HT-29 cells. The extracts did not induce toxicity in these eukaryotic models.

CONCLUSION

The chemical composition of GBE was affected by in vitro digestion, but the antioxidant and antigenotoxic activities persisted. Therefore, G. biloba extract may be suitable for use as food additive and contribute to a healthy colon.

Polyphenol Health Effects on Cardiovascular and Neurodegenerative Disorders: A Review and Meta-Analysis

Several studies have demonstrated that polyphenol-enriched diets may have beneficial effects against the development of degenerative diseases, including atherosclerosis and disorders affecting the central nervous system. This activity has been associated not only with antioxidant and anti-inflammatory properties, but also with additional mechanisms, such as the modulation of lipid metabolism and gut microbiota function. However, long-term studies on humans provided controversial results, making the prediction of polyphenol impact on health uncertain. The aim of this review is to provide an overview and critical analysis of the literature related to the effects of the principal dietary polyphenols on cardiovascular and neurodegenerative disorders. We critically considered and meta-analyzed randomized controlled clinical trials involving subjects taking polyphenol-based supplements. Although some polyphenols might improve specific markers of cardiovascular risk and cognitive status, many inconsistent data are present in literature. Therefore, definitive recommendations for the use of these compounds in the prevention of cardiovascular disease and cognitive decline are currently not applicable. Once pivotal aspects for the definition of polyphenol bioactivity, such as the characterization of pharmacokinetics and safety, are addressed, it will be possible to have a clear picture of the realistic potential of polyphenols for disease prevention.

[Pharmacology of the drugs prescribed for chronic venous diseases]

The main groups of the drugs used for pharmacotherapy of chronic venous disease are considered. The main therapeutic targets of the drugs including their effect on venous wall tone, permeability and inflammation are described.

Nanoparticle-conjugated nutraceuticals exert prospectively palliative of amyloid aggregation

Alzheimer's disease (AD), an age-related neurodegenerative disease, the most common causes of dementia is a multifactorial pathology categorized by a complex etiology. Numerous nutraceuticals have been clinically evaluated, but some of the trials failed. However, natural compounds have some limitations due to their poor bioavailability, ineffective capability to cross the blood-brain barrier, or less therapeutic effects on AD. To overcome these disadvantages, nanoparticle-conjugated natural products could promote the bioavailability and enhance the therapeutic efficacy of AD when compared with a naked drug. This application generates and implements new prospect for drug discovery in neurodegenerative diseases. In this article, we confer AD pathology, review natural products in clinical trials, and ascertain the importance of nanomedicine coupled with natural compounds for AD.

The Potential Use of Plant Natural Products and Plant Extracts with Antioxidant Properties for the Prevention/Treatment of Neurodegenerative Diseases: In Vitro, In Vivo and Clinical Trials

Neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease and Huntington's disease, present a major health issue and financial burden for health care systems around the world. The impact of these diseases will further increase over the next decades due to increasing life expectancies. No cure is currently available for the treatment of these conditions; only drugs, which merely alleviate the symptoms. Oxidative stress has long been associated with neurodegeneration, whether as a cause or as part of the downstream results caused by other factors. Thus, the use of antioxidants to counter cellular oxidative stress within the nervous system has been suggested as a potential treatment option for neurological disorders. Over the last decade, significant research has focused on the potential use of natural antioxidants to target oxidative stress. However, clinical trial results have lacked success for the treatment of patients with neurological disorders. The knowledge that natural extracts show other positive molecular activities in addition to antioxidant activity, however, has led to further research of natural extracts for their potential use as prevention or treatment/management of neurodegenerative diseases. This review will cover several in vitro and in vivo research studies, as well as clinical trials, and highlight the potential of natural antioxidants.

Tailor-Made Deep Eutectic Solvents for Simultaneous Extraction of Five Aromatic Acids from Ginkgo biloba Leaves

Ginkgo biloba leaves have various health benefits due to the presence of bioactive compounds such as polyprenyl acetates, flavonoids, and terpene trilactones. However, there is little literature reported on the aromatic acids in Ginkgo biloba leaves. In this work, five aromatic acids including shikimic acid (SA), 6-hydroxykynurenic acid (6-HKA), protocatechuic acid (PA), gallic acid (GAA), and p-hydroxybenzoic acid (PHBA) were simultaneously extracted from Ginkgo biloba leaves by employing the green deep eutectic solvents (DESs). A DES tailor-made from xylitol, glycolic acid and 1,5-pentanedioic acid at a molar ratio of 1:3:1 with 50% (w/w) water addition, named as NGG50, gave higher extraction yields for the five aromatic acids. Main factors affecting the extraction process were further optimized. The highest extraction yields of SA, GAA, 6-HKA, PA, and PHBA were 94.15 ± 0.96 mg/g, 332.69 ± 5.19 μg/g, 25.90 ± 0.61 μg/g, 429.89 ± 11.47 μg/g and 67.94 ± 0.37 μg/g, respectively. The NGG50-based extraction process developed here was a successful attempt of simultaneously extracting five aromatic acids from Ginkgo biloba leaves for the first time, which could provide a new exploitation direction of Ginkgo biloba leaves.

Human pharmacokinetics of ginkgo terpene lactones and impact of carboxylation in blood on their platelet-activating factor antagonistic activity

Terpene lactones are a class of bioactive constituents of standardized preparations of Ginkgo biloba leaf extract, extensively used as add-on therapies in patients with ischemic cardiovascular and cerebrovascular diseases. This investigation evaluated human pharmacokinetics of ginkgo terpene lactones and impact of their carboxylation in blood. Human subjects received oral YinXing-TongZhi tablet or intravenous ShuXueNing, two standardized ginkgo preparations. Their plasma protein-binding and platelet-activating factor antagonistic activity were assessed in vitro. Their carboxylation was assessed in phosphate-buffered saline (pH 7.4) and in human plasma. After dosing YinXing-TongZhi tablet, ginkgolides A and B and bilobalide exhibited significantly higher systemic exposure levels than ginkgolides C and J; after dosing ShuXueNing, ginkgolides A, B, C, and J exhibited high exposure levels. The compounds' unbound fractions in plasma were 45-92%. Apparent oral bioavailability of ginkgolides A and B was mostly >100%, while that of ginkgolides C and J was 6-15%. Bilobalide's bioavailability was probably high but lower than that of ginkgolides A/B. Terminal half-lives of ginkgolides A, B, and C (4-7 h) after dosing ShuXueNing were shorter than their respective values (6-13 h) after dosing YinXing-TongZhi tablet. Half-life of bilobalide after dosing the tablet was around 5 h. Terpene lactones were roughly evenly distributed in various body fluids and tissues; glomerular-filtration-based renal excretion was the predominant elimination route for the ginkgolides and a major route for bilobalide. Terpene lactones circulated as trilactones and monocarboxylates. Carboxylation reduced platelet-activating factor antagonistic activity of ginkgolides A, B, and C. Ginkgolide J, bilobalide, and ginkgo flavonoids exhibited no such bioactivity. Collectively, differences in terpene lactones' exposure between the two preparations and influence of their carboxylation in blood should be considered in investigating the relative contributions of terpene lactones to ginkgo preparations' therapeutic effects. The results here will inform rational clinical use of ginkgo preparations.

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.

Follow that botanical: Challenges and recommendations for assessing absorption, distribution, metabolism and excretion of botanical dietary supplements

Botanical dietary supplements are complex mixtures containing one or more botanical ingredient(s), each containing numerous constituents potentially responsible for its purported biological activity. Absorption, distribution, metabolism, and excretion (ADME) data are critical to understand the safety of botanical dietary supplements, including their potential for pharmacokinetic botanical-drug or botanical-botanical interactions. However, ADME data for botanical dietary supplements are rarely available and frequently inadequate to characterize their fate in vivo. Based on an assessment of the current status of botanical dietary supplements ADME research, the following key areas are identified that require robust data for human safety assessment: 1) phytochemical characterization including contaminant analysis and botanical authentication; 2) in vitro and/or in vivo data for identifying potential botanical-botanical or botanical-drug interactions and active/marker constituents; 3) robust ADME study design to include systemic exposure data on active/marker constituents using traditional or novel analytical chemistry and statistical approaches such as poly-pharmacokinetics; and 4) investigation of human relevance. A case study with Ginkgo biloba extract is used to highlight the challenges and proposed approaches in using ADME data for human safety assessment of botanical dietary supplements.

Ginkgo biloba extract EGb 761® in the symptomatic treatment of mild-to-moderate dementia: a profile of its use

EGb 761^® (Tanakan^®) is a standardized extract of Ginkgo biloba leaves that has demonstrated protective properties against neuronal and vascular damage. Overall, in randomized, placebo-controlled clinical trials and meta-analyses in adults with mild-to-moderate dementia, EGb 761^® displayed positive effects, with changes from baseline in outcomes related to cognition, behaviour and global change that are generally better than those shown with placebo. EGb 761^® is generally well tolerated, with no safety issues being identified during its many years of widespread use.

Efficient extraction of proanthocyanidin from Ginkgo biloba leaves employing rationally designed deep eutectic solvent-water mixture and evaluation of the antioxidant activity

Proanthocyanidin (PAC) holds strong free radicals scavenging ability and is widely used as oxygen free radical scavenger. Huge demand, safety and economic aspect are forcing the PAC extraction to explore new resource and greener solvent. An efficient extraction method of PAC from Ginkgo biloba leaves was established by employing deep eutectic solvent (DES)-water mixture. After a rational design, a DES-water mixture (named as Ch-M₅₅) was chosen as the extraction solvent, which was prepared from choline chloride and malonic acid at a molar ratio of 1:2 with water addition of 55% (w/w). The main factors affecting the extraction yield were statistically optimized using a central composite design combined with response surface methodology (RSM). The optimal conditions were obtained as follows: extraction temperature of 65 °C, extraction time of 53 min and Ch-M₅₅ to solid ratio of 10.57:1 (v/w, mL/g). The PAC extraction yield was 22.19 ± 0.71 mg/g under the optimized conditions, which was much higher than those of conventional organic solvents. The antioxidant activity of PAC extracted by Ch-M₅₅ was similar to that of 70% acetone, but a little less than 70% methanol and 70% ethanol. The differences in constituent and polymerization degree of PAC extracted by different solvents might account for the difference in antioxidant activity. In consideration of biodegradability and pharmaceutical acceptability, the Ch-M₅₅-based extraction method is obviously efficient, green and ecofriendly. Extraction of PAC from Ginkgo biloba leaves also provides a new PAC resource.

Anti-neuroinflammatory effects of Ginkgo biloba extract EGb761 in LPS-activated primary microglial cells

BACKGROUND

Neuroinflammation is a key factor of Alzheimer's disease (AD) and other neurodegenerative conditions. Microglia are the resident mononuclear immune cells of the central nervous system (CNS). They play an essential role in the maintenance of homeostasis and responses to neuroinflammation. Ginkgo biloba extract EGb 761 is one of the most commonly used natural medicines owing to its established efficacy and remarkable biological activities especially in respect to CNS diseases. However, only few studies have addressed the effects and mechanisms of Ginkgo biloba extract in microglia activation.

METHODS

We measured the production of pro-inflammatory mediators and cytokines by ELISA and analyzed gene expressions by qRT-PCR and Western Blot in LPS treated cultured primary rat microglia.

RESULTS

The Ginkgo biloba extract EGb 761 significantly inhibited the release of prostaglandin E₂ (PGE₂) and differentially regulated the levels of pro-inflammatory cytokines. The inhibition of LPS-induced PGE₂ release in primary microglia was partially dependent on reduced protein synthesis of mPGES-1 and the reduction in the activation of cytosolic phospholipase A2 (cPLA2) without altering COX-2 enzymatic activity, inhibitor of kappa B alpha (IkappaBalpha) degradation, and the activation of multiple mitogen activated protein kinases (MAPKs). Altogether, we showed that EGb 761 reduces neuro-inflammatory activation in primary microglial cells by targeting PGE₂ release and cytokines.

CONCLUSION

Ginkgo biloba extract EGb 761 displayed anti-neuroinflammatory activity in LPS-activated primary microglia cells. EGb 761 was able to reduce neuroinflammatory activation by targeting the COX/PGE₂ pathway. This effect might contribute to the established clinical cognitive efficacy in Alzheimer's disease, vascular and mixed dementia.

Formulation Screening and Freeze-Drying Process Optimization of Ginkgolide B Lyophilized Powder for Injection

The purpose of this study was to prepare ginkgolide B (GB) lyophilized powder for injection with excellent appearance and stable quality through a formulation screening and by optimizing the freeze-drying process. Cremophor EL as a solubilizer, PEG 400 as a latent solvent, and mannitol as an excipient were mixed to increase the solubility of GB in water to more than 18 times (about from 2.5 × 10^-4 mol/L (0.106 mg/mL) to 1.914 mg/mL). Formulation screening was conducted by orthogonal design where the content of GB in the solution before lyophilization (using external standard method of HPLC) and reconstitution time after lyophilization were the two evaluation indexes. The optimized formulations were GB in an amount of 2 mg/mL, Cremophor EL in an amount of 16% (v/v), PEG 400 in an amount of 9% (v/v), mannitol in an amount of 8% (w/v), and the solution pH of 6.5. Through four single-factor experiments (GB adding order, preparation temperature of GB solution, adding amount, and adsorption time of activated carbon), the preparation process of GB solution was confirmed. The glass transition temperature of maximally GB freeze-concentrated solution was - 17.6°C through the electric resistance method. GB lyophilized powder began to collapse at - 14.0°C, and the fully collapsed temperature was - 13.0°C, which were determined by freeze-drying microscope. When the collapse temperature was determined, the primary drying temperature was obtained. Thereby, the freeze-drying curve of GB lyophilized powder was initially identified. The freeze-drying process was optimized by orthogonal design, the qualified product appearance and residual moisture content were the two evaluation indexes. The optimized process parameters and process were (1) shelf temperature, decreased from room temperature to - 45.0°C, at 0.5°C/min in 2 h; (2) shelf temperature increased from - 45.0 to - 25.0°C, at 0.1°C/min, maintained for 3 h, and the chamber pressure was held at 10 Pa; (3) shelf temperature was increased from - 25.0 to - 15.0°C at 0.1 °C/min, maintained for 4 h, and the chamber pressure was held at 10 Pa; and (4) shelf temperature was increased from - 15.0 to 20.0°C at 1.0 °C/min, maintained for 4 h, and the chamber pressure was raised up to 80 Pa. In these lyophilization process conditions, the products complied with relevant provisions of the lyophilized powders for injection. Meanwhile, the reproducibility was satisfactory. Post-freezing annealing had no significantly beneficial effects on shortening the freeze-drying cycle and improving the quality of GB lyophilized powder.

Toxicity Potential of Nutraceuticals

By the turn of the twenty-first century, the use of nutraceuticals became increasingly popular in both humans and animals due to their easy access, cost-effectiveness, and tolerability with a wide margin of safety. While some nutraceuticals are safe, others have a toxic potential. For a large number of nutraceuticals, no toxicity/safety data are available due to a lack of pharmacological/toxicological studies. The safety of some nutraceuticals can be compromised via contamination with toxic plants, metals, mycotoxins, pesticides, fertilizers, drugs of abuse, etc. Knowledge of pharmacokinetic/toxicokinetic studies appears to play a pivotal role in safety and toxicity assessment of nutraceuticals. Interaction studies are essential to determine efficacy, safety, and toxicity when nutraceuticals and therapeutic drugs are used concomitantly. This chapter describes various aspects of nutraceuticals, particularly their toxic potential, and the factors influencing their safety.

Alkaloid profiling of herbal drugs using high resolution mass spectrometry

Herbal infusions are consumed worldwide thanks to their "natural" beneficial effects, also due to the presence of alkaloids, although these compounds can have poisonous effects. A method combining online solid-phase purification with high resolution mass spectrometry was used to define the alkaloid profiles of 117 herbs and 7 commercial blends. Forty-one alkaloids were quantified in reference to analytical standards, while the presence of a further 116 was confirmed based on accurate mass, retention time, and fragmentation profile. The targeted study showed that 52% of herbs and 42% of commercial blends contained at least one alkaloid. Pyrrolizidines were the most commonly present (26% of samples), with concentrations generally ranging from the quantification limit to roughly 100 μg kg^-1 . Moreover, a homemade infusion was studied, finding on average 45% and 6% lower extraction for pyrrolizidine and steroidal alkaloids, respectively. Nevertheless, the migration of pyrrolizidines was confirmed. The study confirmed the frequent presence, natural or accidental, of alkaloids in commercial infusion herbs, highlighting the urgent need for routine and accurate controls.

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.

Neuroprotective Effect of Fagopyrum dibotrys Extract against Alzheimer's Disease

Accumulated evidence suggests that polyphenolic antioxidants present in herbs play important roles in prevention of AD; the molecular mechanisms behind neuroprotective actions rely on the phenols through different effects on the amyloid-aggregation pathway. Fagopyrum dibotrys is a traditional herbal medicine which contains high quantity phenols. In present study, we investigate the beneficial pharmacological actions of Fagopyrum dibotrys extract in the APP/PS1 transgenic mouse mode; meanwhile, effects of the FDE on the fibrillation and cytotoxicity of Aβ peptide were evaluated in vitro. After 9-month treatment, FDE exhibited multifunctional properties on Aβ-related pathologies, which cleaned Aβ deposits in the brain and decreased Aβ burden in the plasma, inhibited microhaemorrhage, and reduced reactive microglia in APP/PS1 transgenic mice and also promoted Aβ fibrils disaggregation and inhibited neurotoxicity induced by Aβ in SH-SY5Y cells. These results highlighted that FDE is an AD type pathology modulator with therapeutic potential against AD.

Cardioprotective Action of Ginkgo biloba Extract against Sustained β-Adrenergic Stimulation Occurs via Activation of M2/NO Pathway

Ginkgo biloba is the most popular phytotherapic agent used worldwide for treatment of several human disorders. However, the mechanisms involved in the protective actions of Ginkgo biloba on cardiovascular diseases remain poorly elucidated. Taking into account recent studies showing beneficial actions of cholinergic signaling in the heart and the cholinergic hypothesis of Ginkgo biloba-mediated neuroprotection, we aimed to investigate whether Ginkgo biloba extract (GBE) promotes cardioprotection via activation of cholinergic signaling in a model of isoproterenol-induced cardiac hypertrophy. Here, we show that GBE treatment (100 mg/kg/day for 8 days, v.o.) reestablished the autonomic imbalance and baroreflex dysfunction caused by chronic β-adrenergic receptor stimulation (β-AR, 4.5 mg/kg/day for 8 days, i.p.). Moreover, GBE prevented the upregulation of muscarinic receptors (M₂) and downregulation of β₁-AR in isoproterenol treated-hearts. Additionally, we demonstrated that GBE prevents the impaired endothelial nitric oxide synthase activity in the heart. GBE also prevented the pathological cardiac remodeling, electrocardiographic changes and impaired left ventricular contractility that are typical of cardiac hypertrophy. To further investigate the mechanisms involved in GBE cardioprotection in vivo, we performed in vitro studies. By using neonatal cardiomyocyte culture we demonstrated that the antihypertrophic action of GBE was fully abolished by muscarinic receptor antagonist or NOS inhibition. Altogether, our data support the notion that antihypertrophic effect of GBE occurs via activation of M₂/NO pathway uncovering a new mechanism involved in the cardioprotective action of Ginkgo biloba.

Efficacy and safety of Ginkgo biloba standardized extract in the treatment of vascular cognitive impairment: a randomized, double-blind, placebo-controlled clinical trial

OBJECTIVES

The aim of this randomized, double-blind, placebo-controlled trial was to determine the efficacy and safety of Ginkgo biloba extract in patients diagnosed with vascular cognitive impairment (VCI).

METHODS

A total of 90 patients (aged 67.1±8.0 years; 59 women) were randomly allocated (1:1:1) to receive G. biloba 120 mg, G. biloba 60 mg, or placebo during a 6-month period. Assessment was made for efficacy indicators, including neuropsychological tests scores (Sandoz Clinical Assessment Geriatric Scale, Folstein Mini-Mental State Examination, Mattis Dementia Rating Scale, and Clinical Global Impression) and transcranial Doppler ultrasound findings. Safety indicators included laboratory findings, reported adverse reactions, and clinical examination.

RESULTS

At the end of 6-month study period, G. biloba 120 and 60 mg showed a statistically significant positive effect in comparison with placebo only on the Clinical Global Impression score (2.6±0.8 vs 3.1±0.7 vs 2.8±0.7, respectively; P=0.038). The Clinical Global Impression score showed a significant deterioration from the baseline values in the placebo group (-0.3±0.5; P=0.021) as opposed to G. biloba groups. No significant differences were found in the transcranial Doppler ultrasound findings. Adverse reactions were significantly more common and serious in the placebo group (16 subjects) than in either of the two G. biloba extract groups (eight and nine subjects, respectively), whereas laboratory findings and clinical examinations revealed no differences between the groups receiving G. biloba extract and placebo.

CONCLUSION

According to our results, G. biloba seemed to slow down the cognitive deterioration in patients with VCI, but the effect was shown in only one of the four neuropsychological tests administered. However, because of this mild effect in combination with a few adverse reactions, we cannot say that it is ineffective or unsafe either. Further studies are still needed to provide unambiguous evidence on the efficacy and safety of G. biloba extract.

Effect of Garlic, Gingko, and St. John's Wort Extracts on the Pharmacokinetics of Fexofenadine: A Mechanistic Study

The aim of this study was to determine the effects of garlic and ginkgo herbal extracts on the pharmacokinetics of the P-glycoprotein (P-gp)/organic anion-transporting polypeptides (Oatps) substrate fexofenadine. Male rats were dosed orally with garlic (120 mg/kg), ginkgo (17 mg/kg), St. John's wort (SJW; 1000 mg/kg; positive control), or Milli-Q water for 14 days. On day 15, rats either were administered fexofenadine (orally or i.v.), had their livers isolated and perfused with fexofenadine, or had their small intestines divided into four segments (SI-SIV) and analyzed for P-gp and Oatp1a5. In vivo, SJW increased the clearance of i.v. administered fexofenadine by 28%. Garlic increased the area under the curve_0-∞ and maximum plasma concentration of orally administered fexofenadine by 47% and 85%, respectively. Ginkgo and SJW had no effect on the oral absorption of fexofenadine. In the perfused liver, garlic, ginkgo, and SJW increased the biliary clearance of fexofenadine with respect to perfusate by 71%, 121%, and 234%, respectively. SJW increased the biliary clearance relative to the liver concentration by 64%. The ratio of liver to perfusate concentrations significantly increased in all treated groups. The expression of Oatp1a5 in SI was increased by garlic (88%) and SJW (63%). There were no significant changes in the expression of P-gp. Induction of intestinal Oatp1a5 by garlic may explain the increased absorption of orally administered fexofenadine. Ginkgo had no effect on the expression of intestinal P-gp or Oatp1a5. A dual inductive effect by SJW on opposing intestinal epithelial transport by Oatp1a5 and P-gp remains a possibility.

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.

Natural Compounds as a Therapeutic Intervention following Traumatic Brain Injury: The Role of Phytochemicals

There has been a tremendous focus on the discovery and development of neuroprotective agents that might have clinical relevance following traumatic brain injury (TBI). This type of brain injury is very complex and is divided into two major components. The first component, a primary injury, occurs at the time of impact and is the result of the mechanical insult itself. This primary injury is thought to be irreversible and resistant to most treatments. A second component or secondary brain injury, is defined as cellular damage that is not immediately obvious after trauma, but that develops after a delay of minutes, hours, or even days. This injury appears to be amenable to treatment. Because of the complexity of the secondary injury, any type of therapeutic intervention needs to be multi-faceted and have the ability to simultaneously modulate different cellular changes. Because of diverse pharmaceutical interactions, combinations of different drugs do not work well in concert and result in adverse physiological conditions. Research has begun to investigate the possibility of using natural compounds as a therapeutic intervention following TBI. These compounds normally have very low toxicity and have reduced interactions with other pharmaceuticals. In addition, many natural compounds have the potential to target numerous different components of the secondary injury. Here, we review 33 different plant-derived natural compounds, phytochemicals, which have been investigated in experimental animal models of TBI. Some of these phytochemicals appear to have potential as possible therapeutic interventions to offset key components of the secondary injury cascade. However, not all studies have used the same scientific rigor, and one should be cautious in the interpretation of studies using naturally occurring phytochemical in TBI research.

Long-term pre-treatment of antioxidant Ginkgo biloba extract EGb-761 attenuates cerebral-ischemia-induced neuronal damage in aged mice

Antioxidant activity has been attributed to the neuroprotective effects of Ginkgo biloba extract EGb-761 on brain disorders including ischemic stroke. It is suggested that oxidative stress implicates in neuron injuries during aging. However, whether or not EGb-761 could be used to treat age-related cerebral ischemia is unclear. In the present study, we directly studied the protective effects of EGb-761 in brain ischemia in the mice with different age. As expected, the recovery from brain damages was impaired in aged mice (24 months) in an animal model of middle cerebral artery occlusion (MCAO). Notably, a 12-month pretreatment of EGb-761 significantly ameliorated the ischemic injury of aged mice in a dose-dependent manner. The decreased stroke severity by EGb-761 was suggested by the reduced infarct volumes and brain edema, accompanied by alleviated oxidative stress. Additionally, we further explored the potential involvement of extra-cellular signal-regulated kinase (ERK) activation by MCAO in aged mice. ERK activation after MCAO was diminished by EGb-761, and this reduction may be mediated through an upregulation of phosphatase PP2A by EGb-761. These observations collectively support that natural antioxidant EGb-761 could be potentially exploited as an effective approach in treating neurological injury during aging.

Ginkgolic Acid Protects against Aβ-Induced Synaptic Dysfunction in the Hippocampus

Ginkgo leaf is the most used form of supplement for cognitive ailments. The standardized extract formulation EGb 761 is a dietary supplement with proven benefit in several neurological and psychiatric conditions including memory decline in Alzheimer's disease, schizophrenia and dementia. Ginkgolic acid (GA) is a component of this extract which shows pleiotropic effects including antitumoral and anti-HIV action; however, its effect on memory is still unknown. Here, we carried out an electrophysiological analysis to investigate the effects of GA on long term potentiation and synaptic transmission at CA1 hippocampal synapses. We also evaluated the potential rescuing effect of GA on the synaptic dysfunction following in vitro application of Aβ. Data obtained indicate that GA exerts neuroprotective effects against Aβ-induced impairment of neurotransmitter release and synaptic plasticity.

Development of two step liquid-liquid extraction tandem UHPLC-MS/MS method for the simultaneous determination of Ginkgo flavonoids, terpene lactones and nimodipine in rat plasma: Application to the pharmacokinetic study of the combination of Ginkgo biloba dispersible tablets and Nimodipine tablets

A sensitive, reliable and accurate UHPLC-MS/MS method has been firstly established and validated for the simultaneous quantification of ginkgo flavonoids, terpene lactones and nimodipine in rat plasma after oral administration of Ginkgo biloba dispersible tablets, Nimodipine tablets and the combination of the both, respectively. The plasma samples were extracted by two step liquid-liquid extraction, nimodipine was extracted by hexane-ether (3:1, v/v) at the first step, after that ginkgo flavonoids and terpene lactones were extracted by ethyl acetate. Then the analytes were successfully separated by running gradient elution with the mobile phase consisting of 0.1% formic acid in water and methanol at a flow rate of 0.6mL/min. The detection of the analytes was performed on a UHPLC-MS/MS system with turbo ion spray source in the negative ion and multiple reaction monitoring (MRM) mode. The calibration curves for the determination of all the analytes showed good linearity (R(2)>0.99), and the lower limits of quantification were 0.50-4.00ng/mL. Intra-day and inter-day precisions were in the range of 3.6%-9.2% and 3.2%-13.1% for all the analytes. The mean extraction recoveries of the analytes were within 69.82%-103.5% and the matrix were within 82.8%-110.0%. The validated method had been successfully applied to compare the pharmacokinetic parameters of ginkgo flavonoids, terpene lactones and nimodipine in rat plasma after oral administration of Ginkgo biloba dispersible tablets, Nimodipine tablets with the combination of the both. There were no statistically significant differences on the pharmacokinetic behaviors of all the analytes between the combined and single administration groups. Results showed that the combination of the two agents may avoid dosage adjustments in clinic and the combination is more convenient as well as efficient on different pathogenesis of cerebral ischemia.

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.

Selective potentiation of alpha 1 glycine receptors by ginkgolic acid

Glycine receptors (GlyRs) belong to the superfamily of pentameric cys-loop receptor-operated channels and are involved in numerous physiological functions, including movement, vision, and pain. In search for compounds performing subunit-specific modulation of GlyRs we studied action of ginkgolic acid, an abundant Ginkgo biloba product. Using patch-clamp recordings, we analyzed the effects of ginkgolic acid in concentrations from 30 nM to 25 μM on α1–α3 and α1/β, α2/β configurations of GlyR and on GABA_ARs expressed in cultured CHO-K1 cells and mouse neuroblastoma (N2a) cells. Ginkgolic acid caused an increase in the amplitude of currents mediated by homomeric α1 and heteromeric α1/β GlyRs and provoked a left-shift of the concentration-dependent curves for glycine. Even at high concentrations (10–25 μM) ginkgolic acid was not able to augment ionic currents mediated by α2, α2/β, and α3 GlyRs, or by GABA_AR consisting of α1/β2/γ2 subunits. Mutation of three residues (T59A/A261G/A303S) in the α2 GlyR subunit to the corresponding ones from the α1 converted the action of ginkgolic acid to potentiation with a distinct decrease in EC₅₀ for glycine, suggesting an important role for these residues in modulation by ginkgolic acid. Our results suggest that ginkgolic acid is a novel selective enhancer of α1 GlyRs.

The protective mechanism of Ginkgolides and Ginkgo flavonoids on the TNF-α induced apoptosis of rat hippocampal neurons and its mechanisms in vitro

Objective

To explore the neuroprotective mechanism of Ginkgolides or Ginkgo flavonoids on the TNF-α induced apoptosis of cultured rat hippocampal neurons.

Materials and methods

Primary hippocampal neurons were isolated from rat brains and cultured with (model group) or without (control group) addition of tumor necrosis factor-α (TNF-α, final concentration of 40 ng/ml) to induce apoptosis. TNF-α induced cultures were divided into model group, Ginkgolides pre-treatment group (20 μg/ml) and Ginkgo flavonoids pre-treatment group (12 μg/ml). CCK8 was used to assess cell viability while Hoechst 33258 staining, Flow cytometry and TUNEL kits were all employed to determine apoptotic neurons. Expression levels of Bcl-2, Bax, Caspase-3, Caspase-7, Caspase-8, Caspase-9 and Cytc were estimated by qRT-PCR.

Results

Cell viability was significantly improved in Ginkgolides pre-treatment group or Ginkgo flavonoids pre-treatment group compared with that in model group. Apoptotic neurons were significantly less in Ginkgolides pre-treatment group or Ginkgo flavonoids pre-treatment group than those in model group. Transcription levels of caspase-7, caspase-8, caspase-3, caspase-9, Bax and Cytc were down-regulated, while transcription levels of Bcl-2 was up-regulated in Ginkgolides pre-treatment or Ginkgo flavonoids pre-treatment group than those in model group.

Conclusions

Ginkgolides and Ginkgo flavonoids might protect against apoptosis of hippocampal neurons through inhibiting death receptor pathway or mitochondrial pathway under TNF-α background.

Over-the-counter anti-oxidant therapies for use in multiple sclerosis: A systematic review

BACKGROUND

Anti-oxidant compounds that are found in over-the-counter (OTC) supplements and foods are gaining interest as treatments for multiple sclerosis (MS). They are widely used by patients, sometimes without a clear evidence base.

OBJECTIVE

We conducted a systematic review of animal and clinical research to determine the evidence for the benefits of OTC anti-oxidants in MS.

METHODS

Using predefined criteria, we searched key databases. Two authors scrutinized all studies against inclusion/exclusion criteria, assessed study risk-of-bias and extracted results.

RESULTS

Of the 3507 titles, 145 met criteria and included compounds, α(alpha)-lipoic acid (ALA), anti-oxidant vitamins, Ginkgo biloba, quercetin, resveratrol and epigallocatechin-3-gallate (ECGC). The strongest evidence to support OTC anti-oxidants was for compounds EGCG and ALA in animal models; both consistently showed anti-inflammatory/anti-oxidant effects and reduced neurological impairment. Only vitamin E, Ginkgo biloba and ALA were examined for efficacy in pilot clinical trials with either conflicting evidence or evidence of no benefit.

CONCLUSION

OTC anti-oxidants EGCG and ALA show the most consistent benefit, however only in preclinical studies. There is no evidence that they alter MS relapses or progression. Future work should focus on testing more of these therapies for clinical efficacy before recommending them to MS patients.

In vitro antioxidant, collagenase inhibition, and in vivo anti-wrinkle effects of combined formulation containing Punica granatum, Ginkgo biloba, Ficus carica, and Morus alba fruits extract

BACKGROUND

In phytotherapy, the therapeutic potential is based on the combined action of different herbal drugs. Our objective was to evaluate the antioxidant, anti-collagenase (in vitro), and anti-wrinkle (in vivo) effect of combined formulation containing Ginkgo biloba, Punica granatum, Ficus carica, and Morus alba fruits extract.

METHODS

Antioxidant evaluation was based on the scavenging activity of free radicals (1,1-diphenyl-2-picrylhydrazyl, H2O2, and O2 (-)) and the anti-collagenase activity was based on the reduction of collagenase enzyme in vitro. In an in vivo study, 21 female subjects were examined in a placebo-controlled trail. Facial wrinkle, especially the crow's feet region of eyes, was treated with topical formulated 2% cream for 56 days and compared with the placebo.

RESULTS

In the in vitro study, the combination of fruits extract showed a higher antioxidant activity which was comparable with the positive standard (ascorbic acid, butylated hydroxyanisole, and Trolox). The data also showed a dose-dependent inhibition of collagenase. In the in vivo study, treatment with 2% formulated cream for 56 days significantly reduced the percentage of wrinkle depth, length, and area with 11.5, 10.07, and 29.55, respectively.

CONCLUSION

The combined formulation of fruit extracts showed excellent antioxidative and anti-collagenase activity as well as a significant effect on anti-wrinkle activity on human skin.

Long-term treatment with Ginkgo biloba extract EGb 761 improves symptoms and pathology in a transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by extracellular deposits of amyloid β peptide (Aβ) and microglia-dominated neuroinflammation. The therapeutic options for AD are currently limited. In this study, we investigated the antiinflammatory effects and the underlying molecular mechanisms of Ginkgo biloba extract EGb 761 when administered to TgCRND8 AD mice, which overexpress human Alzheimer's amyloid precursor protein (APP) specifically in neurons. We gave APP-transgenic mice EGb 761 as a dietary supplement for 2 or 5months. Plasma concentrations of EGb 761 components in mice were in the same range as such concentrations in humans taking EGb 761 at the recommended dose (240mg daily). Treatment with EGb 761 for 5months significantly improved the cognitive function of the mice as measured by the Barnes Maze test. It also attenuated the loss of synaptic structure proteins, such as PSD-95, Munc18-1, and SNAP25. Treatment with EGb 761 for 5months inhibited microglial inflammatory activation in the brain. The effects of treatment with EGb 761 for 2months were weak and not statistically significant. Moreover, EGb 761 activated autophagy in microglia. Treatment with EGb 761 decreased Aβ-induced microglial secretion of TNF-α and IL-1β and activation of caspase-1, both of which were abolished by the inhibition of autophagy. Treatment with EGb 761 also reduced the concentrations of NLRP3 protein that colocalized with LC3-positive autophagosomes or autolysosomes in microglia. Additionally, long-term treatment with EGb 761 may reduce cerebral Aβ pathology by inhibiting β-secretase activity and Aβ aggregation. Therefore, long-term treatment with G. biloba extract EGb 761, a clinically available and well-tolerated herbal medication, ameliorates AD pathology by antiinflammatory and Aβ-directed mechanisms.

Ginkgo biloba extract enhances chemotherapy sensitivity and reverses chemoresistance through suppression of the KSR1-mediated ERK1/2 pathway in gastric cancer cells

Kinase suppressor of Ras 1 (KSR1) is a scaffold protein that modulates the activation of the oncogenic mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway. Ginkgo biloba extract (EGb) 761 has been demonstrated to possess antitumor activity that may be related to the KSR1-mediated ERK signaling pathway. However, the roles and its underlying mechanism in gastric cancer are unclear. In the present study, 62 gastric cancer and matched normal tissues were exploited for immunohistochemistry and real-time fluorescent quantitative PCR detection. Results of the immunohistochemistry showed that the expression of ERK1/2 and p-ERK1/2 was correlated to the expression of KSR1 and p-KSR1 in the gastric cancer tissues, and the overexpression of KSR1, p-KSR1, ERK1/2 and p-ERK1/2 was significantly associated with histological grade, TNM stage, lymph node and distant metastasis. Compared with the normal tissues, the relative mRNA copy values of KSR1, ERK1 and ERK2 in the cancer tissues were 2.43 ± 0.49, 2.10 ± 0.44 and 3.65 ± 0.94. In addition, the expression of KSR1, p-KSR1, ERK1/2 and p-ERK1/2 in human gastric cancer multidrug resistant SGC-7901/CDDP cells was higher than that in the SGC-7901 cells as detected by the methods of immunocytochemistry and western blot analysis. EGb 761 not only suppressed expression of these proteins induced by cisplatin (CDDP) and etoposide in SGC-7901 cells, but also inhibited expression of these proteins in the SGC-7901/CDDP cells. Meanwhile, the proliferation-suppressing and apoptosis-inducing capacities of CDDP and etoposide were enhanced following combined treatment with EGb 761. Moreover, EGb 761 reduced the malondialdehyde (MDA) content and elevated the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the tumor cells. These results confirmed that activation of the KSR1-mediated ERK1/2 signaling pathway may contribute to tumorigenesis, metastasis and chemoresistance of human gastric cancer. EGb 761 enhanced the chemotherapy sensitivity and reversed the chemoresistance through suppression of the KSR1-mediated ERK1/2 pathway in gastric cancer cells, and the underlying mechanism may be related to its antioxidative activity.

Advancement in the chemical analysis and quality control of flavonoid in Ginkgo biloba

Flavonoids are the main active constituents in Ginkgo biloba L., which have been suggested to have broad-spectrum free-radical scavenging activities. This review summarizes the recent advances in the chemical analysis of the flavonoids in G. biloba and its finished products (from 2009 to 2014), including chemical composition, sample preparation, separation, detection and different quality criteria. More than 70 kinds of flavonoids have been identified in this plant. In this review, various analytical approaches as well as their chromatographic conditions have been described, and their advantages/disadvantages are also compared. Quantitative analyses of Ginkgo flavonoids applied by most pharmacopeias start with an acidic hydrolysis followed by determination of the resulting aglycones using HPLC. But increasing direct assay of individual flavonol glycosides found that many adulterated products were still qualified by the present tests. To obtain an authentic and applicable analytical approach for quality evaluation of Ginkgo and its finished products, related suggestions and opinions in the recent publications are mainly discussed in this review. This discussion on chemical analyses of Ginkgo flavonoids will also be found as a significant guide for widely varied natural flavonoids.

The Synergistic Beneficial Effects of Ginkgo Flavonoid and Coriolus versicolor Polysaccharide for Memory Improvements in a Mouse Model of Dementia

This study reports the combination of Ginkgo flavonoid (GF) and Coriolus versicolor polysaccharide (CVP) in the prevention and treatment of a mouse model of Alzheimer's disease (AD). GF is a traditional health product, and CVP is the main active ingredient of the medicinal fungus Coriolus versicolor. The Morris water maze test, the Y maze, and the step-through test showed that the combinational use of CVP and GF synergistically improved memory in a mouse model of AD. Based on H&E staining analysis, the combination of CVP and GF decreased the severity of the pathological findings in the brain. Given that the expression of IL-1β, IL-6, and TNF-α was downregulated, the inflammation response in AD mice was considered to be inhibited. The downregulation of GFAP further demonstrated that inflammation was reduced in the brain of AD mice following treatment. Moreover, the expression levels of superoxide dismutase (SOD) and catalase (CAT) were elevated in the brains of treated mice, indicating that oxidation levels were reduced upon the combination treatment. Our results provide new insights into the efficient utilization of traditional medicine for preventing dementia.

Effects of compound Ginkgo biloba on intestinal permeability in rats with alcohol-induced liver injury

The mechanism of compound Ginkgo biloba (CGB) to alleviate the liver injury induced by gut-derived endotoxin in alcoholic liver disease.