Neuroprotective effect of carvedilol, an adrenergic antagonist against colchicine induced cognitive impairment and oxidative damage in rat

Remyelinating activities of Carvedilol or alpha lipoic acid in the Cuprizone-Induced rat model of demyelination

Multiple sclerosis (MS) is a complex and multifactorial neurodegenerative disease with unknown etiology, MS is featured by multifocal demyelinated lesions distributed throughout the brain. It is assumed to result from an interaction between genetic and environmental factors, including nutrition. Therefore, different therapeutic approaches are aiming to stimulate remyelination which could be defined as an endogenous regeneration and repair of myelin in the central nervous system. Carvedilol is an adrenergic receptor antagonist. Alpha lipoic acid (ALA) is a well-known antioxidant. Herein, we investigated the remyelination potential of Carvedilol or ALA post-Cuprizone (CPZ) intoxication. Carvedilol or ALA (20 mg/kg/d) was administrated orally for two weeks at the end of the five weeks of CPZ (0.6%) administration. CPZ provoked demyelination, enhanced oxidative stress, and stimulated neuroinflammation. Histological investigation of CPZ-induced brains showed obvious demyelination in the corpus callosum (CC). Both Carvedilol and ALA demonstrated remyelinating activities, with corresponding upregulation of the expression of MBP and PLP, the major myelin proteins, downregulation of the expression of TNF-α and MMP-9, and decrement of serum IFN-γ levels. Moreover, both Carvedilol and ALA alleviated oxidative stress, and ameliorated muscle fatigue. This study highlights the neurotherapeutic potential of Carvedilol or ALA in CPZ-induced demyelination, and offers a better model for the exploring of neuroregenerative strategies. The current study is the first to demonstrate a pro-remyelinating activity for Carvedilol, as compared to ALA, which might represent a potential additive benefit in halting demyelination and alleviating neurotoxicity. However, we could declare that Carvedilol showed a lower neuroprotective potential than ALA.

Candidates for drug repurposing to address the cognitive symptoms in schizophrenia

In the protein-protein interactome, we have previously identified a significant overlap between schizophrenia risk genes and genes associated with cognitive performance. Here, we further studied this overlap to identify potential candidate drugs for repurposing to treat the cognitive symptoms in schizophrenia. We first defined a cognition-related schizophrenia interactome from network propagation analyses, and identified drugs known to target more than one protein within this network. Thereafter, we used gene expression data to further select drugs that could counteract schizophrenia-associated gene expression perturbations. Additionally, we stratified these analyses by sex to identify sex-specific pharmacological treatment options for the cognitive symptoms in schizophrenia. After excluding drugs contraindicated in schizophrenia, we identified 12 drug repurposing candidates, most of which have anti-inflammatory and neuroprotective effects. Sex-stratified analyses showed that out of these 12 drugs, four were identified in females only, three were identified in males only, and five were identified in both sexes. Based on our bioinformatics analyses of disease genetics, we suggest 12 candidate drugs that warrant further examination for repurposing to treat the cognitive symptoms in schizophrenia, and suggest that these symptoms could be addressed by sex-specific pharmacological treatment options.

Neuroprotective repositioning and anti-tau effect of carvedilol on rotenone induced neurotoxicity in rats: Insights from an insilico& in vivo anti-Parkinson's disease study

Current treatments for Parkinson's Disease (PD) only provide symptomatic relief; however, they don't delay the disease progression, hence new treatment options should be considered. Carvedilol is a nonselective β & α1 blocker with additional effects as an antioxidant, anti-inflammatory and neuro protective properties. In this research, an insilico study was conducted to primarily evaluate carvedilol as an anti-parkinsonian and anti-tau protein target. PASS prediction was performed followed by a docking study of carvedilol. Carvedilol yielded promising results and forward guided this study onto its in vivo evaluation. The in vivo study aimed to assess the neuro-protective effects of carvedilol in rotenone-induced rat model of PD and investigate the potential underlying mechanisms. The effects of carvedilol (2.5, 5, and 10 mg/kg) on the measured parameters of open field, catalepsy, Y-maze tests as well as brain histology, and tyrosine hydroxylase (TH) were evaluated. The effective doses (5 and 10 mg/kg) were further tested for their potential anti-tau protein effects. Carvedilol (5 and 10 mg/kg) prevented rotenone-induced motor deficits, spatial memory dysfunction, and histological damage. Additionally, carvedilol significantly inhibited rotenone-induced decrease in TH expression in the striata of the rats. These effects were associated with reduction of rotenone-induced neuro-inflammation, microglial activation and release of glial fibrillary acidic protein (GFAP), along with reduction in N-methyl-D-aspartate receptors activation, alpha-synculein and phospho-Tau (P-Tau) protein expression. Carvedilol also reduced tau protein hyper-phosphosrylation by Glycogen synthase 3β (GSK 3β) inhibition and Phosphoinositide 3-kinase (PI3K) stimulation. Collectively, these results suggest that carvedilol might be a possible candidate for management of PD.

Involvement of oxidative pathways and BDNF in the antidepressant effect of carvedilol in a depression model induced by chronic unpredictable stress

RATIONALE

Depression is a severe psychiatric disorder with oxidative imbalance and neurotrophic deficits as underlying mechanisms.

OBJECTIVES

Based on the antioxidant effects of carvedilol (CARV), here, we aimed to evaluate CARV's effects against depression induced by the chronic unpredictable stress (CUS) model.

METHODS

Female Swiss mice were submitted to the CUS protocol for 21 days. Between days 15 and 22, the animals received CARV (5 or 10 mg/kg) or desvenlafaxine (DVS 10 mg/kg) orally. On the 22nd day, mice were subjected to behavioral tests to evaluate locomotion, depressive-like behavior (tail suspension test), motivation/self-care with the splash test (ST), social interaction, and working memory Y-maze test. The prefrontal cortex (PFC) and hippocampus were dissected to evaluate alterations of oxidative and brain-derived neurotrophic factor (BDNF).

RESULTS

The CUS model reduced locomotion and increased grooming latency, while it reduced the number of groomings in the ST. Both doses of CARV and DVS reverted these alterations. In addition, DVS and CARV reversed CUS model-induced working memory and social interaction deficits. The CUS model decreased hippocampal reduced glutathione (GSH), while DVS and CARV increased GSH in the PFC (CARV5) and hippocampus (CARV5 and 10). The CUS model increased nitrite and malondialdehyde (MDA) concentrations in both areas. All treatments reversed nitrite alterations, while CARV10 changed MDA levels in PFC and all treatments in the hippocampus. The CUS model reduced BDNF levels. CARV10 increased BDNF in the PFC, while both doses of CARV increased hippocampal levels of this neurotrophin.

CONCLUSIONS

CARV presents antidepressant-like effects comparable to those observed with DVS. In addition, it has an antioxidant effect and is capable of increasing BDNF brain concentrations. Further studies are needed to elucidate the mechanisms involved in the antidepressant effect of CARV.

Repurposing Antihypertensive Drugs for the Management of Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder that has affected millions of people worldwide. However, currently, there is no treatment to cure the disease. The AD drugs available in the market only manage the disease symptomatically and the effects are usually short-term. Thus, there is a need to look at alternatives AD therapies. This literature review aims to shed some light on the potential of repurposing antihypertensives to treat AD. Mid-life hypertension has not only been recognised as a risk factor for AD, but its relation with AD has also been well established. Hence, antihypertensives were postulated to be beneficial in managing AD. Four classes of antihypertensives, as well as their potential limitations and prospects in being utilised as AD therapeutics, were discussed in this review.

Carvedilol Exerts Neuroprotective Effect on Rat Model of Diabetic Neuropathy

Diabetic neuropathy (DN) commonly occurs in diabetics, affecting approximately 50% of both type 1 and 2 diabetic patients. It is a leading cause of non-traumatic amputations. Oxidative stress could play a key role in the pathophysiology of DN. This study aimed to investigate the potential neuroprotective effect of carvedilol on STZ-induced DN in rats. Thirty male Sprague Dawley rats (weighing 200–250 g) were randomly divided into five groups (six/group), where group 1 (negative control) received only the vehicle (0.5% of carboxymethyl cellulose orally 1 ml/kg). DN was induced by a single injection of remaining rats with streptozotocin (STZ; 50 mg/kg, i.p.). After diabetes induction, group 2 served as the diabetic untreated animals; while groups 3 and 4 were treated with carvedilol (1 and 10 mg/kg/d, orally, respectively). Group 5 received a-lipoic acid as a reference neuroprotective (100 mg/kg/d, orally). All treatments were continued for 45 days after diabetes induction, followed by behavioural tests. After sacrificing the animals, dorsal root ganglia, and sciatic nerves were collected for histopathological examination and biochemical assessments. Briefly, STZ administration caused cold allodynia, induced oxidative stress, and increased nerve growth factor (NGF) concentration. Nevertheless, carvedilol improved the behavioural tests, ameliorated the oxidative imbalance as manifested by reducing malondialdehyde, restoring glutathione content, and superoxide dismutase activity. Carvedilol also decreased NGF concentration in DRG homogenate. In conclusion, this study demonstrates the neuroprotective effect of carvedilol in an experimentally induced DN rat model through–at least partly–its antioxidant effect and reduced NGF concentration in DRG.

Anti-inflammatory potential of a carvedilol gel in the pulpal tissue of rats after dental bleaching: A histopathological evaluation

AIM

Carvedilol is an antioxidant that decreases inflammation in periodontitis. The hydrogen peroxide (H₂ O₂ ) of bleaching gel causes inflammation and necrosis of the dental pulp. In the present study, we evaluated the anti-inflammatory potential of carvedilol in the pulp of rats after bleaching.

METHODS

The right upper molars of rats received 35% H₂ O₂ (1× 30 minutes), and the left upper molars were used as the control. Half of the rats received carvedilol gel (1× 10 minutes), forming the following groups: bleached, bleached followed by carvedilol (bleached+carvedilol), and control. After 2 and 30 days (N = 7 hemi-maxillae/group), the rats were killed for histological evaluation, and statistical tests were performed (P < 0.05).

RESULTS

After 2 days, the bleached group showed necrosis in the occlusal third of the coronal pulp, and in the bleached+carvedilol group, severe inflammation (P > 0.05), both different from the control (P < 0.05). In the middle third, the bleached group showed severe inflammation, and the bleached+carvedilol group showed moderate inflammation (P > 0.05), with the only difference between the bleached and control groups (P < 0.05). In the cervical third, the bleached group showed moderate inflammation, and the bleached+carvedilol group showed mild inflammation (P > 0.05). The difference again was only between the bleached and control groups (P < 0.05). At 30 days, there was no inflammation and a marked amount of tertiary dentin in bleached teeth (P > 0.05).

CONCLUSION

Carvedilol gel has the potential of minimizing H₂ O₂ damage, especially in deep regions of the dental pulp of rats after bleaching.

Carvedilol can attenuate histamine-induced paw edema and formaldehyde-induced arthritis in rats without risk of gastric irritation

BACKGROUND AND AIM

Rheumatoid arthritis treatment aims to control joint damage and any associated complications such as cardiovascular disease. Most anti-inflammatory drugs have a high tendency to cause gastro-intestinal irritation. The present study is designed to investigate the anti-inflammatory effect of carvedilol and to study its effect on gastric mucosa.

EXPERIMENTAL APPROACH

Lornoxicam (1.3mg/kg) or carvedilol (10mg/kg) was administrated orally 1h before histamine injection into animals of a histamine-induced paw edema model and orally daily for 11days into animals of a formaldehyde-induced arthritis model. Tumor necrosis factor-α and prostaglandin E₂ were measured in animals of the formaldehyde-induced arthritis model. The effect of lornoxicam and carvedilol on gastric mucosa was assessed in normal rats and after induction of cold stress ulcer.

RESULTS

Carvedilol succeeded in reducing hind paw edema in both histamine-induced paw edema and formaldehyde-induced arthritis and in reducing the elevated level of tumor necrosis factor-α and prostaglandin E₂ nearly with near equal efficacy compared with lornoxicam. Carvedilol did not show any ulcerative effect on the gastric mucosa of normal rats, and its use was associated with an improvement of both the gross and histopathological pictures of gastric ulcers in animals of the cold stress ulcer model compared with lornoxicam treated rats.

CONCLUSION

The current findings support the use of carvedilol both in the management of inflammation as well as the prevention of cardiovascular complications in rheumatoid arthritis patients. The use of carvedilol was not associated with any gastro-intestinal tract irritation.

Protective Effects of Vasodilatory Βeta-Blockers Carvedilol and Nebivolol against Glycerol Model of Rhabdomyolysis-Induced Acute Renal Failure in Rats

BACKGROUND

Rhabdomyolysis (RM)-induced acute renal failure (ARF) accounts for about 10-40% of all cases of ARF.

AIM

The present study investigated the possible protective effect of two nitric oxides (NO)-releasing third generation β-blockers, carvedilol (Carv) and nebivolol (Nebi), against RM-mimicking glycerol (Gly)-induced ARF in rats.

MATERIAL AND METHODS

After 24 h dehydration, rats received a single dose of 50% Gly (8 ml/kg, im). They were treated with vehicle, Carv (2.5 mg/kg/day, po) or Nebi (10 mg/kg, po) for 3 successive days starting from an hour prior to Gly injection. Evaluation of blood pressure and locomotor activity was performed during the experiment. 72 h following Gly administration, total protein in the urine, serum levels of creatinine, blood urea nitrogen, sodium and potassium as well as the renal contents of malondialdehyde, reduced glutathione and NO were assessed, together with a histopathological examination of renal tissues.

RESULTS

Carv and Nebi attenuated Gly-induced renal dysfunction and histopathological alterations. They decreased the Gly-induced oxidative stress and increased renal NO concentration. Restoration of normal blood pressure and improvement of locomotor activity were also observed.

CONCLUSION

The results clearly demonstrate protective effects of Carv and Nebi against renal damage involved in RM-induced ARF and suggest a role of their antioxidant and NO-releasing properties.

Ischemic aetiology, self-reported frailty, and gender with respect to cognitive impairment in chronic heart failure patients

Background

Decisive information on the parameters involved in cognitive impairment in patients with chronic heart failure is as yet lacking. Our aim was to determine the functional and psychosocial variables related with cognitive impairment using the mini-mental-state examination (MMSE) with age-and education-corrected scores.

Methods

A cohort study of chronic heart failure patients included in an integrated multidisciplinary hospital/primary care program. The MMSE (corrected for age and education in the Spanish population) was administered at enrolment in the program. Analyses were performed in 525 patients. Demographic and clinical variables were collected. Comprehensive assessment included depression (Yesavage), family function (family APGAR), social network (Duke), dependence (Barthel Index), frailty (Barber), and comorbidities. Univariate and multivariate logistic regression were performed to determine the predictors of cognitive impairment.

Results

Cognitive impairment affected 145 patients (27.6 %). Explanatory factors were gender (OR: 2.77 (1.75–4.39) p < 0.001), ischemic etiology (OR: 1.99 (1.25–3.17) p = 0.004), frailty (OR: 1.58 (0.99 to 2.50, p =0.050), albumin > 3.5 (OR: 0.59 (0.35–0.99) p = 0.048), and beta-blocker treatment (OR: 0.36 (0.17 to 0.76, p = 0.007)). No association was found between cognitive impairment and social support or family function.

Conclusion

The observed prevalence of cognitive impairment using MMSE corrected scores was 27.6 %. A global approach in the management of these patients is needed, especially focusing on women and patients with frailty, low albumin levels, and ischemic aetiology heart failure.

Carvedilol attenuates inflammatory biomarkers and oxidative stress in a rat model of ulcerative colitis

Preclinical Research This study evaluated the effects of the carvedilol, a nonselective β-adrenoceptor anatgonist with α1-adrenoceptor antagonist activity, in a rat model of experimentally induced ulcerative colitis (UC). UC was produced using acetic acid (AA) in animals previously treated with carvedilol (30 mg/kg po, qd) for seven days. Mucus content, lipid peroxidation (LPO) products, sulfhydryl groups, antioxidant enzyme activities, proinflammatory cytokines, prostaglandin E2 and nitric oxide levels were measured in colonic tissues and histopathological changes were assessed. LPO and proinflammatory biomarkers were markedly increased, while mucus content, sulfhydryl groups and enzymatic activities were inhibited in animals administered AA. Pretreatment with carvedilol attenuated LPO elevation, mucus content and sulfhydryl group inhibitions. Antioxidant enzymatic activity and proinflammatory biomarker levels were also restored in carvedilol-pretreated animals. Colonic protection associated with carvedilol pretreatment was further confirmed by histopathological assessment and found to be similar to the standard therapy of mesalazine (100 mg/kg po qd), suggesting that the effects of carvedilol action may be attributable to its anti-inflammatory and antioxidant properties.

Microglial Inhibitory Mechanism of Coenzyme Q10 Against Aβ (1-42) Induced Cognitive Dysfunctions: Possible Behavioral, Biochemical, Cellular, and Histopathological Alterations

Rationale: Alzheimer’s disease (AD) is a debilitating disease with complex pathophysiology. Amyloid beta (Aβ) (1-42) is a reliable model of AD that recapitulates many aspects of human AD.

Objective: The intent of the present study was to investigate the neuroprotective potential of Coenzyme Q10 (CoQ10) and its modulation by minocycline (microglial inhibitor) against Aβ (1-42) induced cognitive dysfunction in rats.

Method: Intrahippocampal (i.h.) Aβ (1-42) (1 μg/μl; 4μl/site) were administered followed by drug treatment with galantamine (2 mg/kg), CoQ10 (20 and 40 mg/kg), minocycline (50 and 100 mg/kg) and their combinations for a period of 21 days. Various neurobehavioral parameters followed by biochemical, acetylcholinesterase (AChE) level, proinflammatory markers (TNF-α), mitochondrial respiratory enzyme complexes (I-IV) and histopathological examinations were assessed.

Results: Aβ (1-42) administration significantly impaired cognitive performance in Morris water maze (MWM) performance test, causes oxidative stress, raised AChE level, caused neuroinflammation, mitochondrial dysfunction and histopathological alterations as compared to sham treatment. Treatment with CoQ10 (20 and 40 mg/kg) and minocycline (50 and 100 mg/kg) alone for 21 days significantly improved cognitive performance as evidenced by reduced transfer latency and increased time spent in target quadrant (TSTQ), reduced AChE activity, oxidative damage (reduced LPO, nitrite level and restored SOD, catalase and GHS levels), TNF-α level, restored mitochondrial respiratory enzyme complex (I, II, III, IV) activities and histopathological alterations as compared to Aβ (1-42) treated animals. Further, combinations of minocycline (50 and 100 mg/kg) with CoQ10 (20 and 40 mg/kg) significantly modulates the protective effect of CoQ10 dose dependently as compared to their effect alone.

Conclusion: The present study suggests that the neuroprotective effect of CoQ10 could be due to its microglia inhibitory mechanism along with its mitochondrial restoring and anti-oxidant properties.

The role of Beta-adrenergic receptor blockers in Alzheimer's disease: potential genetic and cellular signaling mechanisms

According to genetic studies, Alzheimer's disease (AD) is linked to beta-adrenergic receptor blockade through numerous factors, including human leukocyte antigen genes, the renin-angiotensin system, poly(adenosine diphosphate-ribose) polymerase 1, nerve growth factor, vascular endothelial growth factor, and the reduced form of nicotinamide adenine dinucleotide phosphate. Beta-adrenergic receptor blockade is also implicated in AD due to its effects on matrix metalloproteinases, mitogen-activated protein kinase pathways, prostaglandins, cyclooxygenase-2, and nitric oxide synthase. Beta-adrenergic receptor blockade may also have a significant role in AD, although the role is controversial. Behavioral symptoms, sex, or genetic factors, including Beta 2-adrenergic receptor variants, apolipoprotein E, and cytochrome P450 CYP2D6, may contribute to beta-adrenergic receptor blockade modulation in AD. Thus, the characterization of beta-adrenergic receptor blockade in patients with AD is needed.

Carvedilol decrease IL-1β and TNF-α, inhibits MMP-2, MMP-9, COX-2, and RANKL expression, and up-regulates OPG in a rat model of periodontitis

Periodontal diseases are initiated primarily by Gram-negative, tooth-associated microbial biofilms that elicit a host response that causes osseous and soft tissue destruction. Carvedilol is a β-blocker used as a multifunctional neurohormonal antagonist that has been shown to act not only as an anti-oxidant but also as an anti-inflammatory drug. This study evaluated whether Carvedilol exerted a protective role against ligature-induced periodontitis in a rat model and defined how Carvedilol affected metalloproteinases and RANKL/RANK/OPG expression in the context of bone remodeling. Rats were randomly divided into 5 groups (n = 10/group): (1) non-ligated (NL), (2) ligature-only (LO), and (3) ligature plus Carvedilol (1, 5 or 10 mg/kg daily for 10 days). Periodontal tissue was analyzed for histopathlogy and using immunohistochemical analysis characterized the expression profiles of MMP-2, MMP-9, COX-2, and RANKL/RANK/OPG and determined the presence of IL-1β, IL-10 and TNF-α, myeloperoxidase (MPO), malonaldehyde (MDA) and, glutathione (GSH). MPO activity in the group with periodontal disease was significantly increased compared to the control group (p<0.05). Rats treated with 10 mg/kg Carvedilol presented with significantly reduced MPO and MDA concentrations (p<0.05) in addition to presenting with reduced levels of the pro-inflammatory cytokines IL-1 β and TNF-α (p<0.05). IL-10 levels in Carvedilol-treated rats remained unaltered. Immunohistochemical analysis demonstrated reduced expression of MMP-2, MMP-9, RANK, RANKL, COX-2, and OPG in rats treated with 10 mg/kg Carvedilol. This study demonstrated that Carvedilol affected bone formation/destruction and anti-inflammatory activity in a rat model of periodontitis.

Carvedilol alleviates adjuvant-induced arthritis and subcutaneous air pouch edema: modulation of oxidative stress and inflammatory mediators

Rheumatoid arthritis (RA) is a systemic inflammatory disease with cardiovascular complications as the leading cause of morbidity. Carvedilol is an adrenergic antagonist which has been safely used in treatment of several cardiovascular disorders. Given that carvedilol has powerful antioxidant/anti-inflammatory properties, we aimed to investigate its protective potential against arthritis that may add further benefits for its clinical usefulness especially in RA patients with concomitant cardiovascular disorders. Two models were studied in the same rat; adjuvant arthritis and subcutaneous air pouch edema. Carvedilol (10mg/kg/day p.o. for 21days) effectively suppressed inflammation in both models with comparable efficacy to the standard anti-inflammatory diclofenac (5mg/kg/day p.o.). Notably, carvedilol inhibited paw edema and abrogated the leukocyte invasion to air pouch exudates. The latter observation was confirmed by the histopathological assessment of the pouch lining that revealed mitigation of immuno-inflammatory cell influx. Carvedilol reduced/normalized oxidative stress markers (lipid peroxides, nitric oxide and protein thiols) and lowered the release of inflammatory cytokines (TNF-α & IL-6), and eicosanoids (PGE2 & LTB4) in sera and exudates of arthritic rats. Interestingly, carvedilol, per se, didn't present any effect on assessed biochemical parameters in normal rats. Together, the current study highlights evidences for the promising anti-arthritic effects of carvedilol that could be mediated through attenuation of leukocyte migration, alleviation of oxidative stress and suppression of proinflammatory cytokines and eicosanoids.

Effects of carvedilol on delayed rectifier and transient inactivating potassium currents in rat hippocampal CA1 neurons

1. The aims of the present study were to investigate the mechanism(s) underlying the protective effect of carvedilol against neural damage. 2. The transient inactivating potassium current (I(A) ) and the delayed rectifier potassium current (I(K) ) in rat hippocampal CA1 pyramidal neurons were recorded using whole-cell patch-clamp techniques. 3. Carvedilol (0.1-3 μmol/L) significantly inhibited I(K) with an IC(50) of 1.3 μmol/L and the inhibition was voltage independent. Over the same concentration range, carvedilol had no effect on the amplitude of I(A). At 1 μmol/L, carvedilol did not significantly change the steady state activation curves of I(A) and I(K), but did negatively shift their steady state inactivation curves. Recovery from inactivation was slowed for both I(A) and I(K). The inhibitory effect of carvedilol on I(K) was not affected by the adrenoceptor agonists phenylephrine and prazosin or the adrenoceptor antagonist isoproterenol, but propranolol was able to shift the dose-response curve of carvedilol for I(K) to the right. 4. Because I(K) is the main pathway for loss of intracellular potassium from depolarized neurons, selective obstruction of I(K) by carvedilol could be useful for neuroprotection.

Protective effect of naringin, a citrus flavonoid, against colchicine-induced cognitive dysfunction and oxidative damage in rats

Alzheimer's disease is a neurodegenerative disorder. Central administration of colchicine is well known to cause cognitive impairment and oxidative damage, which simulates sporadic dementia of the Alzheimer type in humans. The present study has been designed to investigate the protective effects of naringin against the colchicine-induced cognitive impairment and oxidative damage in rats. Colchicine (15 microg/5 microL), administered intracerebroventricularly, resulted in poor memory retention in both the Morris water maze and elevated plus maze task paradigms and caused marked oxidative damage. It also caused a significant decrease in acetylcholinesterase activity. Naringin (40 and 80 mg/kg, p.o.) treatment was given daily for a period of 25 days beginning 4 days prior to colchicine administration. Chronic treatment with naringin caused significant improvement in the cognitive performance and attenuated oxidative damage, as evidenced by lowering of malondialdehyde level and nitrite concentration and restoration of superoxide dismutase, catalase, glutathione S-transferase, and reduced glutathione levels, and acetylcholinesterase activity compared to control. The present study highlights the therapeutic potential of naringin against colchicine-induced cognitive impairment and associated oxidative damage.