Preventive effect of Ginkgo biloba extract on apoptosis in rat cerebellar neuronal cells induced by hydroxyl radicals

Nanodelivery of traditional Chinese Gingko Biloba extract EGb-761 and bilobalide BN-52021 induces superior neuroprotective effects on pathophysiology of heat stroke

Military personnel often exposed to high summer heat are vulnerable to heat stroke (HS) resulting in abnormal brain function and mental anomalies. There are reasons to believe that leakage of the blood-brain barrier (BBB) due to hyperthermia and development of brain edema could result in brain pathology. Thus, exploration of suitable therapeutic strategies is needed to induce neuroprotection in HS. Extracts of Gingko Biloba (EGb-761) is traditionally used in a variety of mental disorders in Chinese traditional medicine since ages. In this chapter, effects of TiO2 nanowired EGb-761 and BN-52021 delivery to treat brain pathologies in HS is discussed based on our own investigations. We observed that TiO2 nanowired delivery of EGb-761 or TiO2 BN-52021 is able to attenuate more that 80% reduction in the brain pathology in HS as compared to conventional drug delivery. The functional outcome after HS is also significantly improved by nanowired delivery of EGb-761 and BN-52021. These observations are the first to suggest that nanowired delivery of EGb-761 and BN-52021 has superior therapeutic effects in HS not reported earlier. The clinical significance in relation to the military medicine is discussed.

The Developing Cerebellum as a Target for Toxic Substances: Protective Role of Antioxidants

Cerebellar development begins during the late embryological period and continues to undergo organizational changes long after birth. The cerebellum is particularly susceptible to developmental abnormalities on exposure to oxidants and free radicals, thus leading to oxidative stress. Oxidative stress occurs when there is an imbalance between reactive oxygen species generation and antioxidant defences which may disrupt signalling pathways, leading to cerebellar anomalies and dysfunction. In this regard, this review assesses current research underlining the importance of the cerebellum, provides an update on substances affecting cerebellar development and highlights some promising antioxidants that may play a role in attenuating toxicity in the developing cerebellum. To accomplish this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) system was employed and key scientific databases such as Science Direct, PubMed, Scopus, Web of Science and Google Scholar were searched to explore and collect information on the cerebellum and the role of antioxidants during its development. Originally, 109 articles were obtained but 22 articles which met the inclusion criteria were selected for the review. These findings provide an updated compilation of antioxidants capable of attenuating oxidative damage in the developing cerebellum, thus allowing future interdisciplinary studies in the form of clinical applications for screening and possible development of novel therapeutic agents from the identified products.

Preventing dementia? Interventional approaches in mild cognitive impairment

Mild cognitive impairment (MCI) is defined as an intermediate state between normal cognitive aging and dementia. It describes a status of the subjective impression of cognitive decline and objectively detectible memory impairment beyond normal age-related changes. Activities of daily living are not affected. As the population ages, there is a growing need for early, proactive programs that can delay the consequences of dementia and improve the well-being of people with MCI and their caregivers. Various forms and approaches of intervention for older people with MCI have been suggested to delay cognitive decline. Pharmacological as well as non-pharmacological approaches (cognitive, physiological, nutritional supplementation, electric stimulation, psychosocial therapeutic) and multicomponent interventions have been proposed. Interventional approaches in MCI from 2009 to April 2019 concerning the cognitive performance are presented in this review.

Herbal Medicine for Slowing Aging and Aging-associated Conditions: Efficacy, Mechanisms and Safety

Aging and aging-associated diseases are issues with unsatisfactory answers in the medical field. Aging causes important physical changes which, even in the absence of the usual risk factors, render the cardiovascular system prone to some diseases. Although aging cannot be prevented, slowing down the rate of aging is entirely possible to achieve. In some traditional medicine, medicinal herbs such as Ginseng, Radix Astragali, Ganoderma lucidum, Ginkgo biloba, and Gynostemma pentaphyllum are recognized by the "nourishing of life" and their role as anti-aging phytotherapeutics is increasingly gaining attention. By mainly employing PubMed here we identify and critically analysed 30 years of published studies focusing on the above herbs' active components against aging and aging-associated conditions. Although many plant-based compounds appear to exert an anti-aging effect, the most effective resulted in being flavonoids, terpenoids, saponins, and polysaccharides, which include astragaloside, ginkgolide, ginsenoside, and gypenoside specifically covered in this review. Their effects as antiaging factors, improvers of cognitive impairments, and reducers of cardiovascular risks are described, as well as the molecular mechanisms underlying the above-mentioned effects along with their potential safety. Telomere and telomerase, PPAR-α, GLUTs, FOXO1, caspase-3, bcl-2, along with SIRT1/AMPK, PI3K/Akt, NF-κB, and insulin/insulin-like growth factor-1 pathways appear to be their preferential targets. Moreover, their ability to work as antioxidants and to improve the resistance to DNA damage is also discussed. Although our literature review indicates that these traditional herbal medicines are safe, tolerable, and free of toxic effects, additional well-designed, large-scale randomized control trials need to be performed to evaluate short- and long-term effects and efficacy of these medicinal herbs.

Shenmayizhi Formula Combined with Ginkgo Extract Tablets for the Treatment of Vascular Dementia: A Randomized, Double-Blind, Controlled Trial

Shenmayizhi formula (SMYZF) has been shown to have an effect on vascular dementia (VaD) in previous studies. The aim of this study was to evaluate whether a combination of SMYZF with Ginkgo extract tablets improves mild-to-moderate VaD. In this 12-week, randomized, double-blind, controlled study, we randomly assigned 196 patients with VaD (aged 50-85 years) to either the SMYZF group (n = 98) or the Ginkgo group (n = 98). All patients received Ginkgo extract tablets as a basic treatment, while the SMYZF group also received SMYZF treatment. We evaluated the participants at baseline and after 12 weeks of the intervention for the following: the Mini-Mental State Examination (MMSE), National Institutes of Health Stroke Scale (NIHSS), activities of daily living (ADL), Chinese Medicine Symptom Scale (CM-SS) scores, serum endothelin-1 (ET-1), nitric oxide (NO), vascular endothelial growth factor (VEGF), von Willebrand factor (vWF), neuron-specific enolase (NSE), brain-derived neurotrophic factor (BDNF), and homocysteine (Hcy) serum levels. Both interventions significantly increased MMSE scores and decreased NIHSS, ADL, and CM-SS scores. The SMYZF group showed greater improvement in MMSE, NIHSS, and CM-SS scores. Both groups showed a significant decrease in serum ET-1 and an increase in serum VEGF. Furthermore, serum NO increased, and vWF decreased significantly in the SMYZF group. Changes in serum ET-1 and NO were greater in the SMYZF group. Both groups showed a significant increase in serum BDNF and a decrease in serum NSE and Hcy. Improvement in serum NSE and BDNF was greater in the SMYZF group. SMYZF combined with Ginkgo extract tablets improved vascular endothelial and cognitive functions, as well as the syndromes diagnosed based on the traditional Chinese medicine in patients with VaD.

Ginkgo biloba Prevents Oxidative Stress-Induced Apoptosis Blocking p53 Activation in Neuroblastoma Cells

Oxidative stress has been associated to neuronal cell loss in neurodegenerative diseases. Neurons are post-mitotic cells that are very sensitive to oxidative stress—especially considering their limited capacity to be replaced. Therefore, reduction of oxidative stress, and inhibiting apoptosis, will potentially prevent neurodegeneration. In this study, we investigated the neuroprotective effect of Ginkgo biloba extract (EGb 761) against H₂O₂ induced apoptosis in SK-N-BE neuroblastoma cells. We analysed the molecular signalling pathway involved in the apoptotic cell death. H₂O₂ induced an increased acetylation of p53 lysine 382, a reduction in mitochondrial membrane potential, an increased BAX/Bcl-2 ratio and consequently increased Poly (ADP-ribose) polymerase (PARP) cleavage. All these effects were blocked by EGb 761 treatment. Thus, EGb 761, acting as intracellular antioxidant, protects neuroblastoma cells against activation of p53 mediated pathway and intrinsic mitochondrial apoptosis. Our results suggest that EGb 761, protecting against oxidative-stress induced apoptotic cell death, could potentially be used as nutraceutical for the prevention and treatment of neurodegenerative diseases.

Cytotoxic effects of β-asarone on Sf9 insect cells

β-Asarone is the predominant component of the essential oil of rhizomes of Acorus calamus Linn ( Sweet flag). Although rhizome extracts from this plant have long been used for insect pest control, their cytotoxic effects on insect cells are not well understood. In this study, we evaluated the potency of β-asarone as a natural insecticide by using a Spodoptera frugiperda cell line (Sf9). To assess the cytotoxic effects of β-asarone on Sf9 cells, we observed morphologic changes in treated cells and performed a cell proliferation assay and a DNA fragmentation assay. After 24 and 48 h of treatment with β-asarone, the proliferation of the Sf9 cells was inhibited in a dose-dependent manner, with IC₅₀ values of 0.558 mg/ml at 24 h and 0.253 mg/ml at 48 h. Morphologic changes in β-asarone-treated cells were typical of apoptosis and included loss of adhesion, cell shrinkage, and small apoptotic bodies. The DNA laddering present in β-asarone-treated SF9 cells and annexin V assay confirmed that this compound can induce apoptosis in insect cells. Together, these findings suggest that apoptosis induction may be one mechanism through which β-asarone inhibits the proliferation of insect cells and thus exerts insecticidal effects.

Effects of Ginkgo biloba extract EGb761 on neural differentiation of stem cells offer new hope for neurological disease treatment

Stem cell transplantation has brought new hope for the treatment of neurological diseases. The key to stem cell therapy lies in inducing the specific differentiation of stem cells into nerve cells. Because the differentiation of stem cells in vitro and in vivo is affected by multiple factors, the final differentiation outcome is strongly associated with the microenvironment in which the stem cells are located. Accordingly, the optimal microenvironment for inducing stem cell differentiation is a hot topic. EGb761 is extracted from the leaves of the Ginkgo biloba tree. It is used worldwide and is becoming one of the focuses of stem cell research. Studies have shown that EGb761 can antagonize oxygen free radicals, stabilize cell membranes, promote neurogenesis and synaptogenesis, increase the level of brain-derived neurotrophic factors, and replicate the environment required during the differentiation of stem cells into nerve cells. This offers the possibility of using EGb761 to induce the differentiation of stem cells, facilitating stem cell transplantation. To provide a comprehensive reference for the future application of EGb761 in stem cell therapy, we reviewed studies investigating the influence of EGb761 on stem cells. These started with the composition and neuropharmacology of EGb761, and eventually led to the finding that EGb761 and some of its important components play important roles in the differentiation of stem cells and the protection of a beneficial microenvironment for stem cell transplantation.

Neuroprotective and Antioxidant Effect of Ginkgo biloba Extract Against AD and Other Neurological Disorders

Alzheimer's disease (AD) is the most common progressive human neurodegenerative disorder affecting elderly population worldwide. Hence, prevention of AD has been a priority of AD research worldwide. Based on understanding of disease mechanism, different therapeutic strategies involving synthetic and herbal approaches are being used against AD. Among the herbal extract, Ginkgo biloba extract (GBE) is one of the most investigated herbal remedy for cognitive disorders and Alzheimer's disease (AD). Standardized extract of Ginkgo biloba is a popular dietary supplement taken by the elderly population to improve memory and age-related loss of cognitive function. Nevertheless, its efficacy in the prevention and treatment of dementia remains controversial. Specifically, the added effects of GBE in subjects already receiving "conventional" anti-dementia treatments have been to date very scarcely investigated. This review summarizes recent advancements in our understanding of the potential use of Ginkgo biloba extract in the prevention of AD including its antioxidant property. A better understanding of the mechanisms of action of GBE against AD will be important for designing therapeutic strategies, for basic understanding of the underlying neurodegenerative processes, and for a better understanding of the effectiveness and complexity of this herbal medicine.

Small Molecule Natural Products and Alzheimer's Disease

Alzheimer's disease (AD) is a progressive and deadly neurodegenerative disease that is characterized by memory loss, cognitive impairment and dementia. Several hypotheses have been proposed for the pathogenesis based on the pathological changes in the brain of AD patients during the last few decades. Unfortunately, there is no effective agents/therapies to prevent or control AD at present. Currently, only a few drugs, which function as acetylcholinesterase (AChE) inhibitors or N-methyl-Daspartate (NMDA) receptor antagonists, are available to alleviate symptoms. Since many small molecule natural products have shown their functions as agonists or antagonists of receptors, as well as inhibitors of enzymes and proteins in the brain during the development of central nervous system (CNS) drugs, it is likely that natural products will play an important role in anti-AD drug development. We review recent papers on using small molecule natural products as drug candidates for the treatment of AD. These natural products possess antioxidant, anti-inflammatory, anticholinesterase, anti-amyloidogenic and neuroprotective activities. Moreover, bioactive natural products intended to be used for preventing AD, reducing the symptoms of AD and the new targets for treatment of AD are summarized.

Ginkgo biloba extract improved cognitive and neurological functions of acute ischaemic stroke: a randomised controlled trial

Purpose

To evaluate the efficacy and safety of Ginkgo biloba extract (GBE) in acute ischaemic stroke and its impact on the recurrence of vascular events.

Methods

We conducted a multicentre, prospective, randomised, open label, blinded, controlled clinical trial enrollingpatients with an onset of acute stroke within 7 days from five hospitals in China Jiangsu Province. Participants were assigned to the GBE group (450 mg GBE with 100 mg aspirin daily) or the control group (100 mg aspirin daily) for 6 months. The primary outcome was the decline in the Montreal Cognitive Assessment score at 6 months. Secondary outcomes were other neuropsychological tests of cognitive and neurological function, the the incidence of adverse events and vascular events.

Results

348 patients were enrolled: 179 in the GBE group and 169 in the control group. With 18 patients lost to follow-up, the dropout rate was 5.17%. Admission data between two groups were similar, but in the GBE group there was a marked slow down in the decline in the Montreal Cognitive Assessment scores (-2.77±0.21 vs -1.99±0.23, P=0.0116 (30 days); -3.34±0.24 vs -2.48±0.26, P=0.0165 (90 days); -4.00±0.26 vs -2.71±0.26, P=0.0004 (180 days)) compared with controls. The National Institutes of Health Stroke Scale scores at 12 and 30 days, the modified Rankin Scale scores for independent rate at 30, 90 and 180 days, and the Barthel Index scores at 30, 90 and 180 days in the GBE group were significantly improved compared with controls. Improvements were also observedin GBE groups for Mini-Metal State Examination scores of 30, 90 and 180 days, Webster's digit symbol test scores at 30 days and Executive Dysfunction Index scores at 30 and 180 days. No significant differences were seen in the incidence of adverse events or vascular events.

Conclusions

We conclude that GBE in combination with aspirin treatment alleviated cognitive and neurological deficits after acute ischaemic stroke without increasing the incidence of vascular events.

Trial registration number

ChiCTR-TRC-12002688.

In Vitro and In Vivo Effects of Ginkgo biloba Extract EGb 761 on Seeded Schwann Cells within Poly(DL-lactic acid-co-glycolic acid) Conduits for Peripheral Nerve Regeneration

This study investigated the effects of Ginkgo biloba (EGb 761) extract on seeded Schwann cells within poly(DL-lactic acid-co-glycolic acid) (PLGA) conduits by in vitro and in vivo trials for peripheral nerve regeneration. The seeding efficiency of Schwann cells in serum-deprived culture medium, which simulated the environment of mechanical trauma on an injured nerve site, was improved by adding different dosages of EGb 761 (0, 1, 10, 20, 50, 100, 200 mg/mL). The analytical results showed enhanced cell attachment and survival, reduced LDH release and increased MTT values, particularly in the range 10-100 mg/mL. The PLGA nerve conduits seeded with Schwann cells (6 103 cells) and filled with gelatin containing EGb 761 (0, 10, 50, 100 mg/mL) were implanted to 10-mm right sciatic nerve defects in rats. Autograft was performed as another control. Electromyography was assessed based on the motor unit action potential (MUAP) and fibrillation potential (Fib) at 2, 4, and 6 weeks during all periods. The specimens of the experimental and control groups were harvested for histological analysis at 6 weeks after surgery. The Fib was found to gradually decay, and the MUAP was found not to be present until 4 weeks after surgery. Meanwhile, the experimental groups were all statically better than the control group (without EGb 761) and autografts were observed at 6 weeks, especially at the concentration of 10 mg/mL, where there was higher amplitude of MUAP and a significantly larger number of myelinated axons. This study concluded that a proper concentration of EGb 761 (10-50 mg/mL) promoted seeding efficiency of Schwann cells in a tissue-engineered PLGA conduit. Addition of EGb 761 in Schwann cells-seeded conduit could increase the total number of myelinated axons in nerve regeneration and improve peripheral nerve functional recovery.

2,4-Di-tert-butylphenol from sweet potato protects against oxidative stress in PC12 cells and in mice

In this study, the protective effect of sweet potato extract against hydrogen peroxide-induced oxidative stress and cytotoxicity on the pheochromocytoma cell line (PC12) was investigated. The active component of the sweet potato extract was purified and determined to be 2,4-di-tert-butylphenol. The antioxidant capacity of 2,4-di-tert-butylphenol was measured by using 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) radical. To examine the effects of 2,4-di-tert-butylphenol on amyloid-beta peptide (Aβ1₁₋₄₂)-induced learning and memory impairment in mice, in vivo behavioral tests were performed. Administration of 2,4-di-tert-butylphenol increased alternation behavior in mice injected with Aβ₁₋₄₂. These results suggest that sweet potato extract could be protective against Aβ-induced neurotoxicity, possibly due to the antioxidative capacity of its constituent, 2,4-di-tert-butylphenol.

Effect of Memo®, a natural formula combination, on Mini-Mental State Examination scores in patients with mild cognitive impairment

BACKGROUND

Mild cognitive impairment encompasses the clinical continuum between physiologic age-related cognitive changes and dementia. A variety of medications, including herbal preparations (in particular Ginkgo biloba and Panax ginseng), have been advocated as treatments for cognitive impairment in the elderly. In this study, we investigated the effect of an already marketed dietary supplement (Memo®) combining 750 mg of lyophilized royal jelly with standardized extracts of G. biloba 120 mg and P. ginseng 150 mg on Mini-Mental State Examination (MMSE) scores in patients with mild cognitive impairment.

METHODS

Sixty-six subjects presenting with forgetfulness and satisfying the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-TR) clinical criteria for mild cognitive impairment were randomly divided into an experimental group treated with one Memo capsule before breakfast daily for 4 weeks and a control group who took placebo. The mean change in MMSE score from baseline and reported adverse effects were compared between the two groups.

RESULTS

The mean change in MMSE score in the group treated with Memo for 4 weeks was significantly greater than in the control group (+2.07 versus +0.13, respectively) by the Student's t-test (t = 6.485, P < 0.0001). This was also true after adjusting for age as a covariate and educational level as a factor nested within the treatment groups in a general linear model (analysis of covariance, F = 9.675 [corrected model], P < 0.0001).

CONCLUSION

This combined triple formula may be beneficial in treating the cognitive decline that occurs during the aging process as well as in the early phases of pathologic cognitive impairment typical of insidious-onset vascular dementia and in the early stages of Alzheimer's disease. Larger-sized studies with longer treatment durations are needed to confirm this.

Phase II study of Ginkgo biloba in irradiated brain tumor patients: effect on cognitive function, quality of life, and mood

Ginkgo biloba has been reported to improve cognitive function in older adults and patients with Alzheimer's disease and multi-infarct dementia. We conducted an open-label phase II study of this botanical product in symptomatic irradiated brain tumor survivors. Eligibility criteria included: life expectancy ≥30 weeks, partial or whole brain radiation ≥6 months before enrollment, no imaging evidence of tumor progression in previous 3 months, or stable or decreasing steroid dose, and no brain tumor treatment planned while on study. The Ginkgo biloba dose was 120 mg/day (40 mg t.i.d.) for 24 weeks followed by a 6-week washout period. Assessments performed at baseline, 12, 24 (end of treatment), and 30 weeks (end of washout) included KPS, Functional Assessment of Cancer Therapy-Brain (FACT-Br), Profile of Mood States, Mini-Mental Status Exam, Trail Making Test Parts A (TMT-A) and B (TMT-B), Digit Span Test, Modified Rey Osterrieth Complex Figure (ROCF), California Verbal Learning Test Part II, and the F-A-S Test.

RESULTS

Of the 34 patients enrolled on study, 23 (68 %) completed 12 weeks of treatment and 19 (56 %) completed 24 weeks of treatment. There were significant improvements at 24 weeks in: executive function (TMT-B) (p = 0.007), attention/concentration (TMT-A) (p = 0.002), and non-verbal memory (ROCF-immediate/delayed recall) (p = 0.001/0.002), mood (p = 0.002), FACT-Br subscale (p = 0.001), and the FACT physical subscale (p = 0.003).

CONCLUSIONS

Some improvement in quality of life and cognitive function were noted with Ginkgo biloba. However, treatment with Ginkgo biloba was associated with a high dropout rate.

Ginkgo biloba extract (EGb 761) modulates the expression of dopamine-related genes in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinsonism in mice

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes nigrostriatal dopaminergic neurotoxicity and behavioral impairment in rodents similar to Parkinson's disease. The MPTP mouse model is widely used to evaluate new protective agents. EGb 761 is a well-defined mixture of active compounds extracted from Ginkgo biloba leaves according to a standardized procedure. We have shown that EGb 761 attenuates the loss of striatal dopamine levels and prevents the neurodegeneration of the nigrostriatal pathway induced by MPTP. This finding shows that neuroprotective effects of EGb 761 act, in part, on the dopamine system. Therefore, this study investigates whether EGb 761 exerts dopaminergic neuroprotection through the regulation of dopamine-related gene expression in MPTP-induced Parkinsonism. Male C57BL/6J mice were injected with MPTP (30 mg/kg, i.p.) for 5 days and later with EGb 761 (40 mg/kg, i.p.) daily for 18 days. The expression of selected genes was evaluated in the striatum and midbrain by quantitative PCR. The genes for tyrosine hydroxylase (Th), vesicular monoamine transporter 2 (Vmat2), dopamine transporter (Dat), dopamine D2 receptor (Da-d2r), and transcription factors (Pitx3 and Nurr1) related to dopamine neurotransmission were selected for the analysis. EGb 761 administration to MPTP-treated mice protected Th (41%), Vmat2 (15%), Dat (102%), Da-d2r (46%), Pitx3 (63%), and Nurr1 (148%) mRNA levels in the midbrain, all of which were up-regulated. However, EGb 761 partially reversed the MPTP effect exclusively for Th (48%) and Nurr1 (96%) mRNA in the striatum. Only Th and Nurr1 mRNA and protein levels were regulated by EGb 761 in both regions of the nigrostriatal pathway. This result could be related to the regulation of their transcription. Our results suggest that EGb 761-associated neuroprotection against MPTP neurotoxicity is related to the regulation of the dopamine genes. Moreover, this neuroprotection also involves the regulation of transcription factors such as Nurr1 that are important for the functional maintenance of dopaminergic neurons.

Effect of a phytopharmaceutical medicine, Ginko biloba extract 761, in an animal model of Parkinson's disease: therapeutic perspectives

Ginkgo Biloba extract 761 (EGb 761) is a patented and well-defined mixture of active compounds extracted from Ginkgo biloba leaves. This extract contains two main groups of active compounds, flavonoids (24%) and terpenoids (6%). EGb 761 is used clinically to treat dementia and vaso-occlusive and cochleovestibular disorders. This extract has neuroprotective effects, exerted probably by means of its antioxidant function. Parkinson's disease (PD) is a neurodegenerative disorder that affects 2% of the population older than 60 y. It produces a progressive loss of dopaminergic neurons and depletion of dopamine (DA), leading to movement impairment. The production of reactive oxygen species, which act as mediators of oxidative damage, is linked to PD. This disease is routinely treated with the DA precursor, L-3,4-dihydroxyphenylalanine. However, this produces severe side effects, and its neurotoxic properties can be due to a free radical production. Thus, administration of antioxidant drugs might be used to prevent neuronal death produced by oxidative mechanisms. The use of synthetic antioxidants has decreased because of their suspected activity as carcinogenic promoters. We describe the studies related to the antioxidant effect of EGb 761 in an animal model of PD. It has been shown that EGb761 can provide a neuroprotective/neurorecovery effect against the damage to midbrain DA neurons in an animal model of PD. EGb 761 also has been found to lessen the impairment of locomotion, correlating with an increase of DA and other morphologic and biochemical parameters related to its antioxidant effect in an animal model of PD. These studies suggest it as an alternative in the future treatment of PD.

Oxidative Stress and C-Reactive Protein in Patients with Cerebrovascular Accident (Ischaemic Stroke): The role of Ginkgo biloba extract

OBJECTIVES

This study aimed to investigate the presence of oxidative stress and inflammation in ischaemic stroke patients by measuring malondialdehyde (MDA), total antioxidant status (TAS), and highly-sensitivity C-reactive protein (hsCRP) in the early post-ischaemic period, and to determine the role of Ginkgo biloba therapy in correcting the markers of oxidative stress and inflammation.

METHODS

This study was conducted at Ibn Seena Hospital, Mosul City, Iraq and included 31 cerebrovascular accident (CVA) patients and 30 healthy controls. Ischaemic stroke patients were divided into two groups: group I (n = 15) received conventional therapy; group II (n = 16) received conventional therapy with G. biloba (1500 mg/day) for 30 days. Blood samples were obtained from patients and controls before treatment and assays done of serum levels of MDA, TAS, and hsCRP. For CVA patients, a post-treatment blood sample was taken and the same parameters reassessed.

RESULTS

Compared with the controls, patients' serum levels of MDA, and hsCRP were significantly higher (P ≤0.001) and TAS significantly lower. Group I and II patients reported a significant reduction in serum levels of MDA and hsCRP and a significant increase in serum levels of TAS, in comparison with pre-treatment levels. There was no significant difference (P = 0.19) in serum MDA levels between groups I and II, whereas, serum TAS levels were significantly higher (P ≤0.01) and hsCRP significantly lower (P ≤0.01) in group II.

CONCLUSION

Acute stroke is associated with oxidative stress and inflammatory response in the early period. G. biloba plays a potential role in reducing oxidative damage and inflammatory response.

Identification of Proteins Differentially Expressed in Cerebral Cortexes of Ginkgo biloba Extract (EGb761)-Treated Rats in a Middle Cerebral Artery Occlusion Model — A Proteomics Approach

EGb 761 is a standardized extract of Ginkgo biloba that appears to have a neuroprotective effect against neurodegenerative diseases. Adult male rats were treated with EGb 761 (100 mg/kg) or vehicle prior to middle cerebral artery occlusion (MCAO), and brains were collected 24 h after MCAO. Proteins that were differentially expressed after EGb 761 treatment during cerebral ischemia were detected using two-dimensional gel electrophoresis. Protein spots with more than a 2.5-fold change in intensity between vehicle- and EGb 761-treated groups were identified by mass spectrometry. The levels of peroxiredoxin-2 and protein phosphatase 2A subunit B were significantly decreased in the vehicle-treated group in comparison to the EGb 761-treated group. In contrast, levels of the collapsing response mediator protein 2 (CRMP2) were significantly increased in vehicle-treated animals, while EGb 761 prevented the injury-induced increase of CRMP2. These results suggest that EGb 761 protects neuronal cells against ischemic brain injury through the specific up- and down-modulation of various proteins.

Gingko biloba Extract (EGb 761) Prevents Ischemic Brain Injury by Activation of the Akt Signaling Pathway

EGb 761 is a standardized extract of Gingko biloba that exerts protective effects against ischemic brain injury. This study investigated whether EGb 761 modulates the neuroprotective effects through Akt and its downstream targets, Bad and FKHR. Adult male rats were treated with EGb 761 (100 mg/kg) or vehicle prior to middle cerebral artery occlusion (MCAO). Brains were collected 24 hours after MCAO and infarct volumes were analyzed. EGb 761 significantly reduced infarct volume. Potential activation was mearsured by phosphorylation of Akt at Ser473, Bad at Ser136, and FKHR at Ser256 using Western blot analysis. EGb 761 prevented the injury-induced decrease of pAkt and its down stream targets, pBad and pFKHR. Furthermore, EGb 761 prevented the injury-induced increase of cleaved caspase-3 levels. In conclusion, this study suggests that EGb 761 prevents cell death due to brain injury and that EGb 761 protection is affected by preventing the injury-induce decrease of Akt phosphorylation.

Gingko biloba Extract (EGb 761) Attenuates the Focal Cerebral Ischemic Injury-Induced Decrease in Astrocytic Phosphoprotein PEA-15 Levels

EGb 761 is an extract of Gingko biloba that is neuroprotective against focal cerebral ischemic injury. PEA-15 (phosphoprotein enriched in astrocytes 15) modulates cell proliferation and apoptosis. In this study, we investigated whether EGb 761 regulates the expression of PEA-15 and two phosphorylated forms of PEA-15 (Ser 104 and Ser 116) in middle cerebral artery occlusion (MCAO)-induced injury. Adult male rats were treated with vehicle or EGb 761 (100 mg/kg) prior to MCAO and cerebral cortices were collected 24 h after MCAO. A reduction in expression of PEA-15 and its phosphorylated forms induced by MCAO injury was detected using a proteomic approach. EGb 761 pretreatment prevented the ischemic injury-induced decrease in PEA-15 expression. Western blot analysis demonstrated that EGb 761 attenuates the injury-induced reduction in PEA-15, phospho-PEA-15 (Ser 104), phospho-PEA-15 (Ser 116). Phosphorylation of PEA-15 influences its anti-apoptotic function; a decrease in PEA-15 phosphorylation induces apoptotic cell death. The maintenance of PEA-15 phosphorylation by EGb 761 pretreatment during cerebral ischemic injury indicates that EGb 761 is a neuroprotective against cerebral ischemic injury.

Neuroprotective Effects ofHypericum perforatumon Trauma Induced by Hydrogen Peroxide in PC12 Cells

The standard extracts of Hypericum perforatum L. (SEHP), a well-known medicinal plant, are used for the treatment of depression, exhibited upgrading and significant protective effects on the trauma of PC12 cells induced by 200 μM H2O2in a dose-dependent manner within 24-hour treatment. Cell viability was assessed by the MTT method, and in situ cellular hydrogen peroxide ( H2O2)-induced oxidative stress was examined by measurement of reactive oxygen species (ROS) formation using CDCFH procedures. Intra- and extra-cellular ROS levels decreased significantly to 71.9% and 50.0% of the control at a moderate concentration of 20 μg/ml, respectively, suggesting that SEHP could easily enter the cells and play important roles in reducing ROS levels. Our results were proved by detection of DNA fragmentation and inspection of cell morphology of PC12 cells. SEHP can obviously block DNA fragmentation and prevent the cells from shrinking and turning round of H2O2-induced apoptosis in PC12 cells at concentrations of 10~100 μg/ml. This data suggests SEHP may be a candidate for application in neurodegenerative diseases such as Alzheimer's disease or Parkinson's disease.

Proposed remedies for some developmental disorders

Developmental disorders (DDs) are important leading cause of disability in developed countries and also in the United States. DDs are a group of individual conditions that result from abnormal nervous system development and cause altered function. They can begin at any time from prenatal to 22 years of age and the disability usually presents itself throughout a person's life time. Down syndrome, autism, neural tube defects, schizophrenia, cretinism, and attention-deficit hyperactivity disorder are among the most common DDs that currently plague numerous countries and have varying incidence rates. Their occurrence may be partially attributable to the lack of certain dietary nutrients. Notably, essential vitamins, minerals, and ω-3 fatty acids are often deficient in the general population of America and developed countries and are exceptionally deficient in patients suffering from mental disorders. Typically, most of these disorders are treated with prescription drugs, but many of these drugs cause unwanted side effects. Therefore, psychiatrists recommend alternative or complementary nutritional remedies to overcome the adverse effects of those drugs. Studies have shown that daily supplements of vital nutrients, such as that contain amino acids, often effectively reduce symptoms of the patients, because they are converted into neurotransmitters that alleviate depression and other mental disorders. The aim of this article is to discuss the role of dietary imbalances in the incidence of DD and to emphasize which dietary supplements can aid in the treatment of the above-mentioned DD.

Antidepressant-like effect of a Ginkgo biloba extract (EGb761) in the mouse forced swimming test: role of oxidative stress

EGb761 is a well-defined mixture of active compounds extracted from Ginkgo biloba leaves. This extract is used clinically due to its neuroprotective effects, exerted probably via its potent antioxidant or free radical scavenger action. Previous studies suggest that oxidative stress, via free radical production, may play an important role in depression and animal models for depression-like behavior. Preclinical studies have suggested that antioxidants may have antidepressants properties. The aim of this study was to investigate the antidepressant-like of EGb761 due to its antioxidant role against oxidative stress induced in the forced swimming test, the most widely used preclinical model for assessing antidepressant-like behavior. Male BALB/c mice were pretreated with EGb761 (10mg/kg, ip) daily for 17 days followed by the forced swimming test and spontaneous locomotor activity. Animals were sacrificed to evaluate lipid peroxidation, different antioxidant enzyme activities, serotonin and dopamine content in midbrain, hippocampus and prefrontal cortex. EGb761 significantly decreased the immobility time (39%) in the forced swimming test. This antidepressant-like effect of EGb761 was associated with a reduction in lipid peroxidation and superoxide radical production (indicated by a downregulation of Mn-superoxide dismutase activity), both of which are indicators of oxidative stress. The protective effect of EGb761 is not related to excitatory or inhibitory effects in locomotor activity, and was also associated with the modulation of serotonergic and dopaminergic neurotransmission. It is suggested that EGb761 produces an antidepressant-like effect, and that an antioxidant effect against oxidative stress may be partly responsible for its observed neuroprotective effects.

Punica granatum protects against oxidative stress in PC12 cells and oxidative stress-induced Alzheimer's symptoms in mice

Alzheimer's disease (AD) is a progressive degenerative brain disorder that is characterized by neuronal loss, neurofibrillary tangles, and the abnormal deposition of senile plaque and amyloid β peptide (Aβ). The brains of AD patients are under intense oxidative stress. The overproduction of Aβ leads to Aβ-associated free radical oxidative stress. In this study, the antioxidative and neuronal protective effects of Punica granatum extract were investigated against oxidative stress-induced cytotoxicity in PC12 cells. The ethanol extracts of P. granatum protected PC12 cells from hydrogen peroxide (H₂O₂-induced oxidative stress. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assays revealed a significant increase in cell viability when oxidatively stressed PC12 cells were treated with the P. granatum extract. To examine the effects of P. granatum on Aβ₁₋₄₂-induced learning and memory impairment in mice, in vivo behavioral tests were performed. Treatment with the extract of P. granatum increased step-through latency in mice injected with Aβ₁₋₄₂. The results of this study suggest that the ethanol extract of P. granatum mitigated H₂O₂-induced oxidative stress in PC12 cells. In addition, the extract inhibited neuronal cell death caused by Aβ-induced oxidative stress and Aβ-induced learning and memory deficiency.

Neuroprotective action of Ginkgo biloba on the enteric nervous system of diabetic rats

AIM: To investigate the effect of Ginkgo biloba extract on the enteric neurons in the small intestine of diabetic rats.

METHODS: Fifteen Wistar rats were divided into three groups: control group (C), diabetic group (D) and diabetic-treated (DT) daily with EGb 761 extract (50 mg/kg body weight) for 120 d. The enteric neurons were identified by the myosin-V immunohistochemical technique. The neuronal density and the cell body area were also analyzed.

RESULTS: There was a significant decrease in the neuronal population (myenteric plexus P = 0.0351; submucous plexus P = 0.0217) in both plexuses of the jejunum in group D when compared to group C. With regard to the ileum, there was a significant decrease (P = 0.0117) only in the myenteric plexus. The DT group showed preservation of the neuronal population in the jejunum submucous plexus and in the myenteric plexus in the ileum. The cell body area in group D increased significantly (P = 0.0001) in the myenteric plexus of both segments studied as well as in the ileum submucosal plexus, when compared to C. The treatment reduced (P = 0.0001) the cell body area of the submucosal neurons of both segments and the jejunum myenteric neurons.

CONCLUSION: The purified Ginkgo biloba extract has a neuroprotective effect on the jejunum submucous plexus and the myenteric plexus of the ileum of diabetic rats.

Gingko biloba extract (EGb 761) prevents cerebral ischemia-induced p70S6 kinase and S6 phosphorylation

EGb 761 is an extract of Gingko biloba that exhibits neuroprotective effects against cerebral ischemia. The mammalian target of rapamycin (mTOR) is a critical downstream effector of Akt and a central regulator of ribosomal biogenesis and protein synthesis. We investigated whether EGb 761 regulates Akt downstream targets, including mTOR, p70S6 kinase, and S6 phosphorylation. Adult male rats were treated with vehicle or EGb 761 (100 mg/kg) prior to middle cerebral artery occlusion (MCAO). Brains were collected at 24 hours after MCAO and the cerebral cortex regions were examined. We previously showed that EGb 761 significantly reduces infarct volume and decreases the number of TUNEL-positive cells in the cerebral cortex. Ischemic brain injury induces a decrease in Akt up-stream target, PDK1 phosphorylation. The levels of phospho-mTOR, phospho-p70S6 kinase, and phospho-S6 are subsequently decreased in regions affected by ischemic injury. However, EGb 761 prevented injury-induced decreases in these protein levels. We confirmed that EGb 761 inhibits injury-induced decreases in the number of positive cells for phospho-p70S6 kinase and phospho-S6. The results of this study provide evidence that EGb 761 protects neuronal cells against ischemic brain injury by preventing injury-induced decreases in p70S6 kinase and S6 phosphorylation.

Ginkgo biloba leaf extract (EGb761) combined with neuroprotective agents reduces the infarct volumes of gerbil ischemic brain

Ginkgo biloba exerts many pharmacological actions. It possesses antioxidant properties, the ability of neurotransmitter/receptor modulation and antiplatelet activation factor. This research is designed to investigate the neuroprotective effects of long-term treatment with EGb761 (a standard form of the extract of Ginkgo biloba leaf) in combination with MgSO(4), FK506, or MK-801 on the infarct volume of male gerbils' brain induced by unilateral middle cerebral artery occlusion (MCAO). Thirty-five gerbils fed a standard diet were intragastrically given water or EGb761 (100 mg/kg/day) for one week. Five randomized groups were established: control (n = 7), EGb761 (n = 8), EGb761 + MgSO(4) (n = 7), EGb761 + FK506 (n = 7), and EGb761 + MK-801 (n = 6). The three drug-combination groups were injected with MgSO(4) (90 mg/kg), FK506 (0.5 mg/kg), or MK-801 (1 mg/kg), respectively 30 min before MCAO. Gerbils were anesthetized and craniectomized to expose the right middle cerebral artery (MCA). The right MCA was constricted with an 8-0 suture to produce a permanent ligation for 24 hours. Postmortem infarct volumes were determined by quantitative image analysis of 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain sections. Results showed that the total infarct volumes of the four treated groups either EGb761 alone or in combination with drugs were lower than the control group by 36.1% (EGb761 alone), 40.3% (EGb761 + MgSO(4)), 35.3% (EGb761 + FK506), and 56.4% (EGb761 + MK-801), respectively (p < 0.01). The main affected areas of the brain in the four treated groups were significantly focused between 4 and 6 mm from the frontal pole, when compared to the control group (p < 0.01). All animals in the five groups had infarctions in both cortex and subcortex. These results indicate that long-term pre-treatment of EGb761 administered either alone or in combination with drugs significantly effective neuroprotection on infarct volume in gerbil ischemic brains.

Protective effect of salidroside against H2O2-induced cell apoptosis in primary culture of rat hippocampal neurons

Salidroside, a phenylpropanoid glycoside separated from a medicinal plant Rhodiola rosea, has been documented to have protective effects on neuronal cells in vitro. This study investigated whether salidroside was able to extend its unique neuroprotection to primary cultured rat hippocampal neurons against hydrogen peroxide (H(2)O(2))-induced cell damage. Cell viability tests and cell apoptosis assays confirmed that salidroside pretreatment attenuated H(2)O(2)-stimulated apoptotic cell death in primary culture of hippocampal neurons in a concentration-dependent manner. The measurements of caspase-3 activity, nitric oxide (NO) production, and NO synthase (NOS) activity suggest that the protection of salidroside, shown in this study, might be mediated by inhibiting caspase-3 activity, and antagonizing NO production and NOS activity during H(2)O(2) stimulation. Perhaps, this study might contribute to the development of salidroside as a broad-spectrum agent for preventing and/or treating neuronal damage in neurodegenerative disorders.

Ameliorative effect of 1,2-benzenedicarboxylic acid dinonyl ester against amyloid beta peptide-induced neurotoxicity

Amyloid beta peptide (Abeta)-induced oxidative stress may be linked to neurodegenerative disease. Ethanol extracts of Rosa laevigata protected PC12 cells from hydrogen peroxide-induced oxidative stress. (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) reduction assays revealed a significant increase in cell viability when oxidatively stressed PC12 cells were treated with R. laevigata extract. The effect of R. laevigata on oxidative stress-induced cell death was further investigated by lactate dehydrogenase release assays and trypan blue exclusion assays. Administration of 1,2-benzenedicarboxylic acid dinonyl ester from R. laevigata extract to mice infused with Abeta significantly reversed learning and memory impairment in behavioural tests. After behavioural testing, the mice were sacrificed and brains were collected for the examination of lipid peroxidation, catalase activity and acetylcholinesterase (AchE) activity. These results suggest that 1,2-benzenedicarboxylic acid dinonyl ester from R. laevigata extract may be able to reduce Abeta-induced neurotoxicity, possibly by reducing oxidative stress. Therefore, R. laevigata extract may be useful for the prevention of oxidative stress-induced neurodegenerative disorders.

Ginkgo biloba (EGb 761) extract: effects on the myenteric plexus of the large intestine in Wistar rats

The objective of this study was to evaluate the effect of the purified extract of the Ginkgo biloba (EGb 761) plant on the myenteric plexus in the proximal and distal colon of Wistar rats for a period of 120 days. The experimental rats were divided into two age groups: a young group, sacrificed at age 90 days, and an adult group, sacrificed at age 210 days. We observed a significant reduction in the number of neurons in the myenteric plexus of the adult group compared to the young group in both of the segments studied (P < 0.01). The adult group treated with Ginkgo biloba showed a significant increase in neuronal profile area in both the segments studied (P < 0.001). It can be concluded from these results that treatment with the purified Ginkgo biloba (EGb 761) plant extract at a dose of 50 mg/kg body weight has neurotrophic effect on the myenteric plexus in the proximal and distal colon of rats after 120 days of treatment.

Natural antioxidants protect neurons in Alzheimer's disease and Parkinson's disease

"Modern" medicine and pharmacology require an effective medical drug with a single compound for a specific disease. This seams very scientific but usually has unavoidable side effects. For example, the chemical therapy to cancer can totally damage the immunological ability of the patient leading to death early than non-treatment. On the other hand, natural antioxidant drugs not only can cure the disease but also can enhance the immunological ability of the patient leading to healthier though they usually have several compounds or a mixture. For the degenerative disease such as Alzheimer's disease (AD) and Parkinson's disease (PD), natural antioxidant drugs are suitable drugs, because the pathogenesis of these diseases is complex with many targets and pathways. These effects are more evidence when the clinic trial is for long term treatment. The author reviews the studies on the protecting effects of natural antioxidants on neurons in neurodegenerative diseases, especially summarized the results about protective effect of green tea polyphenols on neurons against apoptosis of cellular and animal PD models, and of genestine and nicotine on neurons against A beta-induced apoptosis of hippocampal neuronal and transgenic mouse AD models.

EGb761 protects against nigrostriatal dopaminergic neurotoxicity in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced Parkinsonism in mice: role of oxidative stress

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes nigrostriatal dopaminergic neurotoxicity and behavioral impairment in rodents. Previous studies suggest that oxidative stress, via free radical production, is involved in MPTP-induced neurotoxicity. The MPTP-treated mouse has been the most widely used model for assessing neuroprotective agents for Parkinson's disease. It has been reported previously that EGb761 prevents dopaminergic neurotoxicity of MPTP. This compound is multifunctional via different mechanisms. Here, we report the neuroprotective effect of EGb761 against oxidative stress induced by MPTP in C57BL/6J mice. EGb761 is a patented and well-defined mixture of active compounds extracted from Ginkgo biloba leaves, with neuroprotective effects, exerted probably via its antioxidant or free radical scavenger action. MPTP administration resulted in a significant decrease in striatal dopamine levels and tyrosine hydroxylase immunostaining in the striatum and substantia nigra pars compacta. Mice receiving EGb761 had significantly attenuated MPTP-induced loss of striatal dopamine levels and tyrosine hydroxylase immunostaining in the striatum and substantia nigra pars compacta. The neuroprotective effect of EGb761 against MPTP neurotoxicity is associated with blockade of lipid peroxidation and reduction of superoxide radical production (indicated by a down-regulation of Mn-superoxide dismutase activity), both of which are indices of oxidative stress. Behavioral analyses showed that EGb761 improved MPTP-induced impairment of locomotion in a manner that correlated with enhancement of striatal dopamine levels. These findings suggest that, in mice, EGb761 attenuates MPTP-induced neurodegeneration of the nigrostriatal pathway and that an inhibitory effect against oxidative stress may be partly responsible for its observed neuroprotective effects.

Evaluation of the effect of Ginkgo biloba extract (EGb 761) on the myenteric plexus of the small intestine of Wistar rats

BACKGROUND

The aging process causes a reduction in the myenteric neuronal population, related to oxidative stress, resulting in malfunctioning of the digestive tract. The purpose of this study was to evaluate the action of Ginkgo biloba extract (EGb 761), an important antioxidant drug, on the myenteric plexus of the jejunum and ileum of rats after treatment for 120 days.

METHODS

Fragments of the jejunum and ileum were collected from three groups of rats: a 90-day-old group (group Y), a 210-day-old group (group A), and a 210-day-old group treated daily with the extract EGb 761 (50 mg/kg body weight) (group TA). The analysis was carried out by using the myosin-V immunohistochemical technique. Neuronal densities were estimated, and a study of the neuronal profile area of 500 neurons from each group was carried out.

RESULTS

In the jejunum, there was a significant neuronal population reduction of 17% only in group A compared with group Y. In the ileum, there was a significant neuronal reduction of 36% in group A compared with group Y, and a significant reduction in group TA of 20%. The difference in the reduction between groups A and TA in the ileum was also significant. In the jejunum, only group A showed a significant increase in neuronal profile area, but in the ileum, there was a significant increase in both groups A and TA.

CONCLUSIONS

A daily dose of 50 mg/kg body weight of Ginkgo biloba extract has a significant neuroprotector effect on the myenteric plexus of the ileum during the aging process in rats.

Dosage effects of ginkgolide B on ethanol-induced cell death in human hepatoma G2 cells

Ginkgolide B is a major active component of Ginkgo biloba extracts, which has been shown to confer anticancer effects by inducing apoptosis or inhibiting oxidative stress generation. Ethanol induces a wide range of cellular toxicities, many of which have been linked to free radical generation. To further elucidate the cellular effects of ginkgolide B, we examined the dose-response effect of ginkgolide B on ethanol-induced toxicity in human Hep G2 cells. TUNEL and MTT assays revealed that ethanol (50-400 mM) induced apoptotic cell death in human Hep G2 cells, and that this effect was inhibited by low (5-25 microM) doses of ginkgolide B, but enhanced by high (50-100 microM) doses of ginkgolide B. Additional experiments revealed that ethanol treatment directly increased intracellular oxidative stress; this effect was enhanced by high doses of ginkgolide B but decreased following treatment with low concentrations of ginkgolide B. The dose-response effects of ginkgolide B on reactive oxygen species (ROS) generation were directly correlated with cell apoptotic biochemical changes including c-Jun N-terminal kinase (JNK) activation, caspase-3 activation, and DNA fragmentation. These results indicate that treatment dosage may determine the effect of ginkgolide B on ethanol-induced ROS generation and cell apoptosis, and support the notion that an appropriate dosage of ginkgolide B may aid in decreasing the toxic effects of ethanol.

Fluoride-induced oxidative stress of osteoblasts and protective effects of baicalein against fluoride toxicity

The key role of osteoblasts in skeletal fluorosis makes the exploration of the possible mechanisms of the fluoride-induced oxidative stress of osteoblasts of great importance. In this article, the in vitro effects of fluoride on the oxidative stress of osteoblasts are presented. To study the inhibitory effect of baicalein on the oxidative stress of osteoblasts, the antioxidant activity of baicalein was evaluated for osteoblasts exposed to fluoride. Calvarial osteoblasts were prepared and respectively treated with alpha-MEM (5% calf serum) containing 0.5, 1.0, 2.0, 4.0, 8.0, 12.0, and 20.0 mg/L fluoride for 48 h. Baicalein (10 micromol/L) was added to the cells for the same period of time as that of the fluoride treatment. Low concentrations of fluoride (0.5-2 mg F-/L) stimulated the mitochondrial activity of osteoblasts and produced significant reaction to the oxidative stress, whereas high concentrations of fluoride (>or=12 mg F-/L) inhibited cell proliferation and the activity of antioxidant enzymes. This suggests that the oxidative stress induced by low concentrations of fluoride might mediate or participate in the process of fluoride inducing the proliferation of osteoblasts. The viability of osteoblasts in the high concentrations of fluoride with the addition of 10 mumol/L baicalein (>or=12 mg/L) was higher than those of the same level of fluoride- treated groups without the addition of baicalein. The protective role of baicalein is obvious as an inhibitor of lipid peroxidation against the damage induced by the high concentration of fluoride.

Preventive Effects of Ginkgo biloba Extract on Ischemia-Reperfusion Injury in Rat Bladder

AIMS

The aim of this experimental study was to evaluate the effects of Ginkgo biloba (EGb 761) on ischemia-reperfusion (I-R) injury in the rat bladder.

METHODS

A bladder I-R injury was induced by abdominal aorta occlusion by ischemia for 30 min, followed by 45 min reperfusion in rats. The rats were divided into four groups of 7 rats each; the control, I-R, and I-R groups were pretreated intraperitoneally with 50 or 100 mg/kg G. biloba 60 min before ischemia induction. Contractile responses to carbachol through isolated organ bath studies were recorded, histological sections were evaluated by light microscopy, and TUNEL staining was performed for the evaluation of apoptosis.

RESULTS

In the I-R group, the contractile responses of the bladder strips were lower than those of the control group (p < 0.01-0.001) and were restored by pretreatment with 100 mg/kg G. biloba (p < 0.05-0.001). Decreased polymorphonuclear leukocyte infiltration was detected in the G. biloba pretreatment groups when compared to the I-R group during histological evaluation. The ratio of TUNEL-positive nuclei was 1.84% in the I-R group, whereas it was decreased in both of the G. biloba pretreatment groups (p < 0.01, p < 0.01).

CONCLUSION

Our data indicated that G. biloba has a preventive effect on I-R injury in rat urinary bladder.

Ondamtanggamibang protects neurons from oxidative stress with induction of heme oxygenase-1

Ondamtanggamibang (ODG) has been used as a remedy to treat psychological anxiety and depression in Oriental medicine. In this study, we found the protective effects of ODG against oxidative stress by induction of the antioxidative enzyme, heme oxygenase (HO)-1 in neuronal PC12 cells. Pretreatment with ODG extract protected neuronal cells from damage induced by H(2)O(2) and 6-hydroxydopamine (6-OHDA), but simultaneous treatment with ODG extract did not. ODG also inhibited the intracellular reactive oxygen species elevation by H(2)O(2) and 6-OHDA. ODG stimulation strongly induced the expression of HO-1 in PC12 cells. The protective effect of ODG extract on oxidative stress-induced damage was suppressed by HO inhibitor, zinc protoporphyrin IX (ZnPP-IX). Taken together, these data suggest that ODG treatment has potential protective effects in neuronal cells under oxidative stress.

Experimental model to assess possible medicinal herb interaction with a radiobiocomplex: qualitative and quantitative analysis of kidney, liver and duodenum isolated from treated rats

Ginkgo biloba extract (EGb) has been used as a medicinal herb. Several biological properties have been associated with this extract, especially, in the increase of the blood flow, in the action as platelet activating factor antagonism and in the prevention of the membrane against the damage caused by free radicals. Radiobiocomplexes have been utilized in various nuclear medicine procedures helping in the diagnosis and/or treatment of human diseases. Many substances have been reported to affect the bioavailability of different radiobiocomplexes. The aim of this work was to evaluate the possible influence of an EGb on the bioavailability of the sodium pertechnetate (99mTcO4Na) and on the morphometry of some organs isolated from rats. These animals were treated with EGb and 99mTcO4Na was injected. The animals were sacrificed, the organs isolated, counted in a well counter and the percentage of radioactivity per gram of each organ was calculated. The results showed that EGb decreased the uptake of the 99mTcO4Na in the duodenum (P<0.05). Moreover, morphometric analysis has revealed significant modifications (P<0.05) on kidney, liver and duodenum due to the cited treatment. It is speculated that the substances present in the EGb could act directly or generate metabolites capable to promote changes in organs (kidney, liver and duodenum), however, only significant alteration in the uptake of the 99mTcO4Na in the duodenum.

Impact of Ginkgo Biloba Extract EGb 761 on ischemia/reperfusion - induced oxidative stress products formation in rat forebrain

Dysbalance in reactive oxygen/nitrogen species is involved in the pathogenesis of cerebral ischemia/reperfusion injury (IRI). Ginkgo biloba extract (Egb 761) pre-treatment was used to observe potential antioxidant/neuroprotective effect after global ischemia/reperfusion. Egb 761 significantly decreased the level of lipoperoxidation (LPO) in rat forebrain total membrane fraction (homogenate) induced by in vitro oxidative stress (Fe(2+)+H(2)O(2)). In animals subjected to four-vessel global ischemia for 15 min and 2-24 h reperfusion the EGb pretreatment slightly decreased LPO in forebrain homogenate. However, as detected in EGb treated group, the LPO-induced lysine conjugates are attenuated in comparison to non-treated IRI animals. EGb significantly improved parameters which indicate forebrain protein oxidative damage after IRI. The intensity of tryptophane fluorescence was increased by the 18.2% comparing to non-treated IRI group and bityrosine fluorescence was significantly decreased in ischemic (21%) and 24 h reperfused (15.9%) group in comparison non-treated IRI group. In addition, the level of total free SH- groups in pre-treated animals was significantly higher comparing to non-treated animals. Our results indicate that extract of EGb 761 has potent antioxidant activity and could play a role to attenuate the IRI-induced oxidative protein modification and lipoperoxidation in the neuroprotective process.

Protective effect of Rosa laevigata against amyloid beta peptide-induced oxidative stress

The amyloid beta (Abeta) peptide is known to increase free radical production in nerve cells, leading to cell death. To investigate the effect of Rosa laevigata against Abeta-induced oxidative damage, in vitro assays and in vivo behavioral tests were performed. R. laevigata showed cell protective effects against oxidative stress-induced cytotoxicity. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) reduction assay exhibited significant increase in cell viability when rat pheochromocytoma (PC 12) cells were treated with R. laevigata extracts. Administration of R. laevigata extracts to mice significantly reversed the Abeta-induced learning and memory impairment in in vivo behavioral tests. These results suggest that R. laevigata extracts can reduce the cytotoxicity of Abeta in PC 12 cells, possibly by the reduction of oxidative stress, and these extracts may be useful in the prevention of Alzheimer's disease.

Radioprotection by plant products: present status and future prospects

The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.

Effects of garcinol on free radical generation and NO production in embryonic rat cortical neurons and astrocytes

Garcinol (camboginol) is a polyisoprenylated benzophenone derivative isolated from fruit rind of Garcinia indica. This study was to elucidate the anti-oxidative and neuroprotective properties of garcinol in rat cortical neuron cultures. First, garcinol protects DNA from Fenton reaction-induced breakage in a dose-dependent manner, with an IC(50) value of 0.32 microM. Garcinol also inhibits xanthine oxidase activity with an IC(50) value of 52 microM and exhibits competitive inhibition. To further ascertain the neuroprotective effects of garcinol in inflammatory-mediated neurotoxicity, we utilized primary neuron/astrocyte co-cultures treated with LPS or cytokine. Our data implicate that treatment with garcinol (5 microM) for 7 days promotes neuronal attachment and neurite extension. The formation of nitric oxide (NO) by LPS in rat astrocytes has been suggested to correlate with the neurodegenerative process. In identifying the effect of neuroprotection, we found that garcinol prevented NO accumulation in LPS-treated astrocytes. Garcinol significantly reduced the expression of LPS-induced inflammatory mediators, such as iNOS and COX-2. Consequently, our results suggest that the neuroprotective effects of garcinol are associated with anti-oxidation and inhibition of iNOS induction in astrocytic cells. Garcinol may exert a similar anti-inflammatory effect and may be neuroprotective against brain injury.

Neuroprotective effect of Ginkgo biloba L. extract in a rat model of Parkinson's disease

The neuroprotective effects of a standardized extract of Ginkgo biloba L. (EGb 761) were investigated on 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in the nigrostriatal dopaminergic system of the rat brain. Rats were given a week of pretreatment with daily administrations of EGb 761. Unilateral striatal injection of 6-OHDA was followed by treatment with EGb 761 for a week. Serial measurement of contralateral forepaw adjusting steps revealed a progressive deficit in motor activity. At 8 weeks after 6-OHDA lesion the number of contralateral forepaw adjusting steps was significantly higher in rats that were treated with high doses of EGb 761 (100 mg/kg daily) than in those treated with low doses (50 mg/kg) or with the vehicle. Dopamine neuron loss in the substantia nigra and a depletion in striatal dopamine corresponded with behavioural deficit. These data suggest that the neuroprotective effects of EGb 761 reduce the behavioural deficit in 6-OHDA lesions in rat and also indicates a possible role for the extract in the treatment of Parkinson's disease.