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

https://doi.org/10.1016/j.neuint.2011.05.007Get rights and content

Abstract

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 (10 mg/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.

Highlights

► EGb761 produces antidepressant-like effect in the forced swimming test. ► Protection by EGb761 is not related to excitatory or inhibitory effects. ► Antidepressant-like effect is associated to a reduction of lipid peroxidation. ► Protection is also related to a downregulation of Mn-superoxide dismutase activity. ► EGb761 has antioxidant effect against oxidative stress in this animal model.

Introduction

Depression is one of the most prevalent, serious, recurrent, incapacitating and costly psychopathologies worldwide. Depression is characterized by altered mood and cognitive functions, and recurrent thoughts of death or suicide with a lifetime incidence of 15–25% (Paykel, 2006). The World Health Organization predicts that depression will be the second cause of loss in human disability-adjusted life years worldwide. Although the mechanism provoking depression has not been clearly elucidated oxidative stress, via free radical production, may play an important role in its pathophysiology (Ng et al., 2008).

Free radicals are produced constitutively under normal physiological conditions. Organisms have developed various defense mechanisms to protect themselves against injury from free radicals including antioxidant enzymes (catalase, glutathione peroxidase, and superoxide dismutase), free radical scavengers, and metal chelating agents (Reiter, 1995). Normally, there is a balance between the generation of free radicals and antioxidant defense system activity. When this balance is altered to favour production of free radicals due to depletion of antioxidant-system components or increased generation of free radicals, oxidative stress occurs (Halliwel, 1992). Oxidative stress leads to damage of polyunsaturated lipids by lipid peroxidation (LP), a chain-reaction that results in numerous degradation products (Niki et al., 1993). In particular, a number of oxidative disturbances in depressed patients have been reported, including enhanced oxidative damage and decreased antioxidant enzyme levels (Ng et al., 2008, Sarandol et al., 2007). Moreover, preclinical studies have suggested that antioxidants (radical scavengers) may have antidepressant properties (Eren et al., 2007, Zafir et al., 2009). It appears reasonable to propose that exogenous antioxidants may be effective in treating depression. Many available synthetic chemical antidepressants have low rates of response, remission and severe adverse effects (Nestler et al., 2002). There are several phytomedicines that have been introduced into psychiatric practice because of greater compliance and milder side effects (Thachil et al., 2007).

The Ginkgo biloba extract termed EGb761 has become one of the most widely used medicinal plant products in Europe. It has been used in clinics for the treatment of cerebrovascular insufficiency, degenerative dementia, peripheral vascular disturbances, and neurosensory disorders (DeFeudis and Drieu, 2000). EGb761 is a well-known extract obtained from leaves of the Ginkgo biloba tree according to a standardized procedure (Drieu, 1986). The patented extract EGb761 contains two main groups of active compounds, flavonoid glycosides (24%) and terpene lactones (6%) of low molecular weight that permit their penetration of the blood–brain barrier (DeFeudis and Drieu, 2000). The flavonoid fraction is composed of three flavonoids: quercetin, kaempferol, and isorhamnetin, which are linked to a sugar. The terpenoid fraction is composed of ginkgolides A, B, C, M, J and bilobalides (Drieu, 1986). EGb761 exhibits a broad spectrum of pharmacological actions in the central nervous system (DeFeudis and Drieu, 2000). It has been proposed that EGb761 has neuroprotective effects, via its potent antioxidant action (Droy-Lefaix et al., 1995, Rojas et al., 2001, Rojas et al., 2008), and as a free radical scavenger (Maitra et al., 1995, Marcocci et al., 1994a, Ni et al., 1996). We have shown that EGb761 could be used as an antioxidant in an animal model of Parkinson’s disease (Rojas et al., 2001, Rojas et al., 2008).

The forced swimming test (FST) is a well-established preclinical animal model for depression and represents an acute stressful event (Porsolt et al., 1977). The existence of oxidative stress in this depression model has been reported (Akhtar et al., 2005). The aim of this study was to investigate the antidepressant-like effect of EGb761 due to its antioxidant role against oxidative stress induced in the forced swimming test. We analyzed spontaneous locomotor activity, serotonin and dopamine turnover ratio, LP, and different antioxidant enzyme activities such as Mn-superoxide dismutase (Mn-SOD), Cu, Zn-superoxide dismutase (Cu, Zn-SOD), glutathione peroxidase, and glutathione reductase.

Section snippets

Materials

EGb761 was provided by Schwabe Pharmaceuticals (Karlsruhe, Germany). Sodium octyl sulfate, sodium metabisulfite, glutathione reductase, NADPH, homovanillic acid, dopamine, serotonin, 5-HIAA, and imipramine hydrochloride were obtained from Sigma–Aldrich (St. Louis, MO, USA). Perchloric acid, thiobarbituric acid, EDTA (Merck, Darmstadt, Germany), polyclonal anti-Cu, Zn-SOD and polyclonal anti-Mn-SOD antibodies (Stressgen Biotechnologies Co., Victoria, BC, Canada), a chemiluminescence detection

EGb761 produces antidepressant-like effect in the FST

EGb761 (10 mg/kg) and imipramine (classical antidepressant) significantly reduced the duration of immobility (41% and 40%, respectively) in the FST (Fig. 1) as compared to the vehicle-treated control group (F2,109 = 22.865, P < 0.001), suggesting an antidepressant-like effect of EGb761.

In the EGb761 dose-response study the degree of antidepressant-like effect was reduced at 5 mg/kg (30%) when compared to the vehicle-treated control group. However, doses of 20 and 40 mg/kg of EGb761 differences were

Discussion

There is an increasing interest in the study of the antidepressant effect of herbs, since treatment of depression with conventional antidepressants results in complete remission in almost 50% of individuals (Nestler et al., 2002). Several research groups have shown that Ginkgo biloba extracts have diverse effects on improvement of mood and cognitive performance, and protection against memory deficits and central nervous system disorders (DeFeudis and Drieu, 2000, Polich and Gloria, 2001, Trick

Acknowledgements

This study was partially supported by the National Council of Science and Technology of Mexico (CONACyT) CB-2008-01, No. 106619. We thank Dr. Robyn Elizabeth Hudson for her valuable comments and Alberto Julio for his technical assistance.

References (59)

  • L. Marcocci et al.

    The nitric oxide-scavenging properties of Gingko biloba extract EGb761

    Biochem. Biophys. Res. Commun.

    (1994)
  • L. Marcocci et al.

    Antioxidant action of G. biloba extract EGb761

    Meth. Enzymol.

    (1994)
  • M.P. Mattson

    Modification of ion homeostasis by lipid peroxidation: roles in neuronal degeneration and adaptive plasticity

    Trends Neurosci.

    (1998)
  • E.J. Nestler et al.

    Neurobiology of depression

    Neuron

    (2002)
  • Y. Ni et al.

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

    Neurosci. Lett.

    (1996)
  • J. Pedraza-Chaverrí et al.

    Garlic ameliorates gentamicin nephrotoxicity: relation to antioxidant enzymes

    Free Radic. Biol. Med.

    (2000)
  • C. Ramassamy et al.

    Prevention by Ginkgo biloba extract (EGb761) and trolox C of the decrease in synaptosomal dopamine or serotonin uptake following incubation

    Biochem. Pharmacol.

    (1992)
  • L. Savegnago et al.

    Monoaminergic agents modulate antidepressant-like effect caused by diphenyl diselenide in rats

    Prog. Neuropsychopharmacol. Biol. Psychiatry

    (2007)
  • K. Sasaki et al.

    Effects of extract of Ginkgo biloba leaves and its constituents on carcinogen-metabolizing enzyme activities and glutathione levels in mouse liver

    Life Sci.

    (2002)
  • J. Sastre et al.

    A Ginkgo biloba extract (EGb761) prevents mitochondrial aging by protecting against oxidative stress

    Free Radic. Biol. Med.

    (1998)
  • A.F. Thachil et al.

    The evidence base of complementary and alternative therapies in depression

    J. Affect. Disord.

    (2007)
  • G. Yadid et al.

    Dynamics of the dopaminergic system as a key component to the understanding of depression

    Prog. Brain Res.

    (2008)
  • F. Yamakura et al.

    Post-translational modifications of superoxide dismutase

    Biochim. Biophys. Acta

    (2010)
  • A. Zafir et al.

    In vivo antioxidant status: a putative target of antidepressant action

    Prog. Neuropsychopharmacol. Biol. Psychiatry

    (2009)
  • M. Akhtar et al.

    Effect of thioperamide on modified forced swimming test-induced oxidative stress in mice

    Basic Clin. Pharmacol. Toxicol.

    (2005)
  • DeFeudis, F.V., 1998. Toxicology of EGb761 in experimental animals and humans: safety of EGb761-products. In: DeFeudis...
  • F.V. DeFeudis et al.

    Ginkgo biloba extract (EGb761) and CNS functions: basic studies and clinical applications

    Curr. Drug Targets

    (2000)
  • K. Drieu

    Preparation and definition of G Biloba extract

    Press. Med.

    (1986)
  • M.T. Droy-Lefaix et al.

    Antioxidant effect of a Ginkgo biloba extract (EGb761) on the retina

    Int. J. Tissue React.

    (1995)
  • Cited by (63)

    • Pharmacologic treatments in preclinical tinnitus models with special focus on Ginkgo biloba leaf extract EGb 761®

      2021, Molecular and Cellular Neuroscience
      Citation Excerpt :

      Although depression and anxiety are not the primary applications of EGb 761®, there are some indications for its efficacy in those areas (Montes et al., 2015). In many preclinical models, EGb 761® and other Ginkgo extracts or single ingredients like ginkgolide B are anti-depressive, anxiolytic, and lower symptoms of stress (Bolanos-Jimenez et al., 1995; Ge et al., 2020; Marcilhac et al., 1998; Naik et al., 2006; Pardon et al., 2000; Porsolt et al., 1990; Rojas et al., 2011; Shah et al., 2003; Walesiuk and Braszko, 2009; Walesiuk et al., 2005, 2006; Ward et al., 2002; Zhang et al., 2019). Those symptoms are often associated, with cause and effect not clearly discernable.

    • Neuroprotective activity of tetramethylpyrazine against 3-nitropropionic acid induced Huntington's disease-like symptoms in rats

      2018, Biomedicine and Pharmacotherapy
      Citation Excerpt :

      In another study, the pretreatment of TMP significantly antagonized the reserpine-induced hypothermia, akinesia, and ptosis which suggested the anti-depressant effect of TMP may be attributed to restoring the monoamine neurotransmitter in the brain [17]. Further, several studies indicated the role of oxidative stress in the pathogenesis of depressive illness and the therapeutic benefit of anti-oxidant supplementation [72,73]. In our present study, the administration of TMP restores the antioxidant defense system in the different regions of the brain may be the contributing factor for its antidepressant activity.

    View all citing articles on Scopus
    View full text