Therapeutic potential of treatment with the flavonoid rutin after cortical focal ischemia in rats

Kaempferol-3-O-(2″-O-galloyl-β-D-glucopyranoside): a novel neuroprotective agent from Diospryros kaki against cerebral ischemia-induced brain injury

Our previous study demonstrated neuroprotective and therapeutic effects of a standardized flavonoid extract from leaves of Diospyros kaki L.f. (DK) on middle cerebral artery occlusion-and-reperfusion (MCAO/R)-induced brain injury and its underlying mechanisms. This study aimed to clarify flavonoid components responsible for the effects of DK using in vitro and in vivo transient brain ischemic models. Organotypic hippocampal slice cultures (OHSCs) subjected to oxygen- and glucose-deprivation (OGD) were performed to evaluate in vitro neuroprotective activity of DK extract and nine isolated flavonoid components. MCAO/R mice were employed to elucidate in vivo neuroprotective effects of the flavonoid component that exhibited the most potent neuroprotective effect in OHSCs. DK extract and seven flavonoids [quercetin, isoquercetin, hyperoside, quercetin-3-O-(2″-O-galloyl-β-D-galactopyranoside), kaempferol, astragalin, and kaempferol-3-O-(2″-O-galloyl-β-D-glucopyranoside) compound (9)] attenuated OGD-induced neuronal cell damage and compound (9) possessed the most potent neuroprotective activity in OHSCs. The MCAO/R mice showed cerebral infarction, massive weight loss, characteristic neurological symptoms, and deterioration of neuronal cells in the brain. Compound (9) and a reference drugs, edaravone, significantly attenuated these physical and neurological impairments. Compound (9) mitigated the blood-brain barrier dysfunction and the change of glutathione and malondialdehyde content in the MCAO mouse brain. Edaravone suppressed the oxidative stress but did not significantly affect the blood-brain barrier permeability. The present results indicated that compound (9) is a flavonoid constituent of DK with a potent neuroprotective activity against transient ischemia-induced brain damage and this action, at least in part, via preservation of blood-brain barrier integrity and suppression of oxidative stress caused by ischemic insult.

Flavonoids and ischemic stroke-induced neuroinflammation: Focus on the glial cells

Ischemic stroke is one of the most cases worldwide, with high rate of morbidity and mortality. In the pathological process of ischemic stroke, neuroinflammation is an essential process that defines the functional prognosis. After stroke onset, microglia, astrocytes and the infiltrating immune cells contribute to a complicated neuroinflammation cascade and play the complicated roles in the pathophysiological variations of ischemic stroke. Both microglia and astrocytes undergo both morphological and functional changes, thereby deeply participate in the neuronal inflammation via releasing pro-inflammatory or anti-inflammatory factors. Flavonoids are plant-specific secondary metabolites and can protect against cerebral ischemia injury via modulating the inflammatory responses. For instances, quercetin can inhibit the expression and release of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, IL-6 and IL-1β, in the cerebral nervous system (CNS). Apigenin and rutin can promote the polarization of microglia to anti-inflammatory genotype and then inhibit neuroinflammation. In this review, we focused on the dual roles of activated microglia and reactive astrocyte in the neuroinflammation following ischemic stroke and discussed the anti-neuroinflammation of some flavonoids. Importantly, we aimed to reveal the new strategies for alleviating the cerebral ischemic stroke.

Propofol improves brain injury induced by chronic cerebral hypoperfusion in rats

To study effect of propofol on cognitive dysfunction and brain injury in a rat model of chronic cerebral hypoperfusion. The bilateral carotid artery ligation (bilateral common carotid artery occlusion and BCCAO) to establish rat model of chronic cerebral hypoperfusion and randomly assigned to 4 groups (n = 10): sham-operation group treated with saline model group, propofol treatment model group, normal saline treatment, propofol treatment in the sham-operation group; continuous intraperitoneal injection of propofol and saline for 12 weeks. Morris water maze was used to evaluate the learning and memory ability of rats. Determination of central cholinergic and oxidative stress in brain tissue by spectrophotometry. Detection of inflammatory response in brain tissue by immunohistochemistry and ELISA method. Detection of neuronal loss in brain tissue by Nissl and TUNEL staining. Compared with the saline-treated model group, propofol in model group significantly increased the rat brain tissue SOD activity (p < .01) and GPX activity (p < .01), decreased the MDA levels (p < .01) and protein carbonyl compound levels (p < .01). The propofol treatment of model group rats hippocampal GFAP-immunoreactive satellite glial cells (p < .01) and immune Iba1-positive microglia cells (p < .01) area percent compared to saline-treated model group decreased significantly. The number of normal propofol treatment of model group rats hippocampus neuron than in physiological saline treatment model group rats was significantly increased (p < .01). Propofol can improve chronic cerebral hypoperfusion in rats induced by cognitive dysfunction and brain damage.

Protective role of rutin against combined exposure to lipopolysaccharide and D-galactosamine-induced dysfunctions in liver, kidney, and brain: Hematological, biochemical, and histological evidences

Protective efficacy of rutin over liver, kidney, and brain dysfunctions was evaluated in this investigation. Rutin (5, 10, and 20 mg/kg) was administered continuously for 6 days followed by single dose of D-galactosamine (300 mg/kg I.P.) and lipopolysaccharide (50 µg/kg I.P.) on the 6th day. Hematological, serological, biochemical, and histological aspects were considered for this study. One-way ANOVA (p ≤ .05) followed by Tukey's HSD post hoc test determined the statistical significance. Serum AST, ALT, ALP, urea, uric acid, and creatinine were increased significantly, whereas albumin and glucose were significantly decreased after combined exposure to LPS and D-GalN. Glutathione level and activity of SOD and catalase were decreased, whereas lipid peroxidation, triglycerides, and cholesterol were increased in tissue samples due to LPS- and D-GalN-induced toxicity. Prophylactic treatment of rutin maintained studied variables toward control claiming the protective role of rutin. PRACTICAL APPLICATION: Rutin is plenteous in a variety of commonly ingested foods such as onion, wine, grape, citrus fruits, tea, and buckwheat. Rutin supplement is recommended for the treatment of various diseases such as varicose veins, internal bleeding, or hemorrhoids. Rutin is better than well-known antithrombic agent, Juniferdin, or Bacitracin. In the present study, rutin showed protective effects against LPS- and D-GalN-induced multiorgan dysfunctions due to its anti-inflammatory and antioxidant properties. Therefore, rutin may be developed and practiced as a food supplement to cope with acute organ dysfunctions caused by inflammatory and oxidative damage.

Important Flavonoids and Their Role as a Therapeutic Agent

Flavonoids are phytochemical compounds present in many plants, fruits, vegetables, and leaves, with potential applications in medicinal chemistry. Flavonoids possess a number of medicinal benefits, including anticancer, antioxidant, anti-inflammatory, and antiviral properties. They also have neuroprotective and cardio-protective effects. These biological activities depend upon the type of flavonoid, its (possible) mode of action, and its bioavailability. These cost-effective medicinal components have significant biological activities, and their effectiveness has been proved for a variety of diseases. The most recent work is focused on their isolation, synthesis of their analogs, and their effects on human health using a variety of techniques and animal models. Thousands of flavonoids have been successfully isolated, and this number increases steadily. We have therefore made an effort to summarize the isolated flavonoids with useful activities in order to gain a better understanding of their effects on human health.

Rutin as Neuroprotective Agent: From Bench to Bedside

Flavonoids are major dietary constituents of plant-based food found ubiquitously in plant kingdom where they are usually present in substantial amounts. Rutin is a flavonol-type polyphenol which consists of the flavonol quercetin and the disaccharide rutinose. Rutin has been reported to exert diverse biological effects such as antitumor and antimicrobial mainly associated to its antioxidant and anti-inflammatory activities. Mental, neurological, and behavioural disorders are an important and growing cause of morbidity. Most of these disorders combine a high prevalence, early onset, progressive clinical course, and impairment of critical brain functions making them a major contributor to the global disease burden. In the present work, the biological in vitro and in vivo effects and the potential therapeutic applications of rutin in neurodegenerative processes are reviewed, as well as their bioavailability and pharmacokinetics, which are essential for a better understanding of its biological effectiveness. Moreover, the present review also provides an overview of the molecular mechanisms through which rutin is proposed to exert its neuroprotective effects.

Rotary jet-spun porous microfibers as scaffolds for stem cells delivery to central nervous system injury

Stem cell transplantation is a promising strategy to treat brain injuries. However, cell-based therapies are limited because poor local cell engraftment. Here, we present a polylactic acid (PLA) scaffold to support mesenchymal stem cells (MSCs) delivery in stroke. We isolated bone marrow MSCs from adult C57/Bl6 mice, cultured them on PLA polymeric rough microfibrous (PRM) scaffolds obtained by rotary jet spinning, and transplanted over the brains of adult C57/Bl6 mice, carrying thermocoagulation-induced cortical stroke. No inflammatory response to PRM was found. MSCs transplantation significantly reduced the area of the lesion and PRM delivery increased MSCs retention at the injury site. In addition, PRM upregulated α6-integrin and CXCL12 production, which may be the cause for greater cell retention at the lesion site and may provide additional benefit to MSCs transplantation procedures. We conclude that PRM scaffolds offer a promising new system to deliver stem cells to injured areas of the brain.

Evaluation of temperature induction in focal ischemic thermocoagulation model

The thermocoagulation model, which consists of focal cerebral ischemia with craniectomy, is helpful in studying permanent ischemic brain lesions and has good reproducibility and low mortality. This study analyzed the best conditions for inducing a focal ischemic lesion by thermocoagulation. We investigated parameters such as temperature and thermal dissipation in the brain tissue during induction and analyzed real-time blood perfusion, histological changes, magnetic resonance imaging (MRI), and motor behavior in a permanent ischemic stroke model. We used three-month-old male Wistar rats, weighing 300–350 g. In the first experiment, the animals were divided into four groups (n = 5 each): one sham surgery group and three ischemic lesion groups having thermocoagulation induction (TCI) temperatures of 200°C, 300°C, and 400°C, respectively, with blood perfusion (basal and 30 min after TCI) and 2,3,5-Triphenyl-tetrazolium chloride (TTC) evaluation at 2 h after TCI. In the second experiment, five groups (n = 5 each) were analyzed by MRI (basal and 24 h after TCI) and behavioral tests (basal and seven days after TCI) with the control group added for the surgical effects. The MRI and TTC analyses revealed that ischemic brain lesions expressively evolved, especially at TCI temperatures of 300°C and 400°C, and significant motor deficits were observed as the animals showed a decrease frequency of movement and an asymmetric pattern. We conclude that a TCI temperature of 400°C causes permanent ischemic stroke and motor deficit.

Flavonoids as Therapeutic Agents in Alzheimer's and Parkinson's Diseases: A Systematic Review of Preclinical Evidences

Alzheimer's and Parkinson's diseases are considered the most common neurodegenerative disorders, representing a major focus of neuroscience research to understanding the cellular alterations and pathophysiological mechanisms involved. Several natural products, including flavonoids, are considered able to cross the blood-brain barrier and are known for their central nervous system-related activity. Therefore, studies are being conducted with these chemical constituents to analyze their activities in slowing down the progression of neurodegenerative diseases. The present systematic review summarizes the pharmacological effects of flavonoids in animal models for Alzheimer's and Parkinson's diseases. A PRISMA model for systematic review was utilized for this search. The research was conducted in the following databases: PubMed, Web of Science, BIREME, and Science Direct. Based on the inclusion criteria, 31 articles were selected and discussed in this review. The studies listed revealed that the main targets of action for Alzheimer's disease therapy were reduction of reactive oxygen species and amyloid beta-protein production, while for Parkinson's disease reduction of the cellular oxidative potential and the activation of mechanisms of neuronal death. Results showed that a variety of flavonoids is being studied and can be promising for the development of new drugs to treat neurodegenerative diseases. Moreover, it was possible to verify that there is a lack of translational research and clinical evidence of these promising compounds.

Therapeutic potential of flavonoids in spinal cord injury

Spinal cord injury (SCI) is a catastrophic event that can profoundly affect a patient's life, with far-reaching social and economic effects. A consequential sequence of SCI is the significant neurological or psychological deficit, which obviously contributes to the overall burden of this condition. To date, there is no effective treatment for SCI. Therefore, developing novel therapeutic strategies for SCI is highly prioritized. Flavonoids, one of the most numerous and ubiquitous groups of plant metabolites, are the active ingredients of traditional Chinese medicine such as Scutellaria baicalensis Georgi (Huang Qin) or Ginkgo biloba (Ying Xin). Accumulated research data show that flavonoids possess a range of key pharmacological properties such as anti-inflammatory, anti-oxidant, anti-tumor, anti-viral, anti-cardiovascular disease, immunomodulatory, and neuroprotective effects. Based on this, the flavonoids show therapeutic potential for SCI diseases. In this paper, we will review the pharmacological properties of different types of flavonoids for the treatment of SCI diseases, and potential underlying biochemical mechanisms of action will also be described.

Rutin alleviates chronic unpredictable stress-induced behavioral alterations and hippocampal damage in mice

Chronic stress results in neurological complications like depression, cognitive dysfunction, and anxiety disorders. In our previous study, we observed that Urtica dioica leaf extract attenuated chronic stress-induced complications. Further, we observed that Urtica dioica contained a great amount of the flavonoid rutin in it. Hence, we aimed to evaluate the effect of rutin on 21days chronic unpredictable stress (CUS) mouse model. CUS led to a decline in locomotion & muscle coordination abilities, cognitive deficits, anxiety, and depression. These neurobehavioral outcomes were associated with neurodegeneration in the CA3 region of the hippocampus as found by H&E staining. Rutin efficiently rescued the CUS-induced behavioral deficits by reducing depression, anxiety, improving cognition, and locomotor & muscle coordination skills. Further, rutin treatment protected the CUS-induced hippocampal neuronal loss. This study establishes the neuroprotective effect of rutin in chronic stress.

Influence of Rhizoglomus irregulare on nutraceutical quality and regeneration of Lycium barbarum leaves under salt stress

Whether arbuscular mycorrhizal fungi augment the nutraceutical quality of crops under salt stress is critical as a potential agronomic practice in salinized farmland. To evaluate the effect of Rhizoglomus irregulare on the nutraceutical quality of Lycium barbarum leaves under salt stress, we analyzed growth parameters and the rutin, polysaccharide, acidic polysaccharide, and amino acids contents of 2 harvests. Inoculation of R. irregulare significantly increased the regenerated bud number (partial eta squared (PES) = 0.577, P < 0.0001) and rutin concentration (PES = 0.544, P < 0.001) of L. barbarum leaves, with and without salt stress. The biomass of the 2nd harvest (PES = 0.355, P = 0.0091) and acidic polysaccharide (PES = 0.518, P = 0.001) of L. barbarum leaves were notably enhanced by R. irregulare under 200 mmol/L salt level. Rhizoglomus irregulare had insignificant effect on polysaccharide (PES = 0.092, P = 0.221) and amino acids levels (PES = 0.263, P = 0.130) in the leaves of L. barbarum. However, inoculation by R. irregulare decreased proline level (PES = 0.761, P = 0.001) in the leaves of L. barbarum when subjected to salt stress. Taken together, these results indicate that R. irregulare significantly improved the nutraceutical quality and facilitated the sustainable production of L. barbarum leaves exposed to salt stress.

Quantification of rutin in rat's brain by UHPLC/ESI-Q-TOF-MS/MS after intranasal administration of rutin loaded chitosan nanoparticles

Rutin (RT), an antioxidant drug, has been utilized to treat cerebral ischemia hence a sensitive quantification method for estimation of RT in brain homogenate is necessary to develop. This study aims to prepare RT loaded Chitosan Nanoparticles (RT-CS-NPs) develop and validate ultra-high performance liquid chromatography-electrospray ionization-synapt mass spectrometric method Synapt Mass Spectrometry (Synapt MS) (UHPLC/ESI-QTOF-MS/MS) for quantification of RT in brain homogenate from Wistar rat. The process of chromatographic separation was carried out on Waters ACQUITY UPLC™ with the components of separation in detail as; column: BEH C-18 with dimension as 2.1 mm×100 mm and particle size 1.7 µm, mobile phase: acetonitrile (85 % v/v/v): 2 mM ammonium formate (15 % v/v/v): formic acid (0.1 % v/v/v) and flow rate: 0.25 mL/min. Liquid-liquid extraction method (LLE), in mixture, i.e. ethyl acetate:acetonitrile, was considered to optimize the recovery of analyte from the brain homogenate of Wistar rat. Over a total run time of 5 minutes, the elution time for RT and internal standard (IS), i.e. Tolbutamide, observed was 2.67 and 2.82 min respectively whereas the transition observed for RT and IS was at m/z 611.1023/303.1071 and 271.1263/155.1073, respectively. Results, regarding various processes and parameters studied for RT as summarized, established a linear dynamic range over a concentration range of 1.00 ng/mL - 1000.0 ng/mL with r²; 0.9991±0.0010. Accuracy for intra and inter-assay in terms of % CV revealed a range of 0.45- 2.11 whereas lower limit of detection (LOD) and quantitation (LOQ) observed was 0.09 ng/mL and 0.142 ng/mL, respectively. The analyte stability as well as method specificity and accuracy, i.e. recovery > 86 %, supports the idea for application of current developed method in order to quantify and evaluate the RT-loaded-CS-NPs for RT determination in brain homogenate after intranasal drug delivery.

Rutin-encapsulated chitosan nanoparticles targeted to the brain in the treatment of Cerebral Ischemia

OBJECTIVE

Rutin, a potent antioxidant, has been reported to reduce the risk of ischemic disease. Our study aims to prepare rutin-encapsulated-chitosan nanoparticles (RUT-CS-NPs) via ionic gelation method and determine its results, based on different parameters i.e. surface morphology characterization, in-vitro or ex-vivo release, dynamic light scattering and differential scanning calorimetry (DSC), for treating cerebral ischemia.

METHODS

UPLC-ESI-Q-TOF-MS/MS was used to evaluate the optimized RT-CS-NPs1 for brain-drug uptake as well as to follow-up the pharmacokinetics, bio-distrbution, brain-targeting efficiency and potential after intranasal administration (i.n.).

KEY FINDINGS

A particle size of <100nm for the formulation, significantly affected by drug:CS ratio, and entrapment efficiency and loading capacity of 84.98%±4.18% and 39.48%±3.16%, respectively were observed for RUT. Pharmacokinetics, bio-distribution, brain-targeting efficiency (1443.48±39.39%) and brain drug-targeting potential (93.00±5.69%) showed enhanced bioavailability for RUT in brain as compared to intravenous administration. In addition; improved neurobehavioral activity, histopathology and reduced infarction volume effects were observed in middle cerebral artery occlusion (MCAO) induced cerebral ischemic rats model after i.n. administration of RUT-CS-NPs.

CONCLUSION

A significant role of mucoadhesive-RT-CS-NPs1 as observed after high targeting potential and efficiency of the formulation prove; RUT-CS-NPs are more effectively accessed and target easily the brain.

Rutin protects against cognitive deficits and brain damage in rats with chronic cerebral hypoperfusion

BACKGROUND AND PURPOSE

Chronic cerebral hypoperfusion is a critical causative factor for the development of cognitive decline and dementia in the elderly, which involves many pathophysiological processes. Consequently, inhibition of several pathophysiological pathways is an attractive therapeutic strategy for this disorder. Rutin, a biologically active flavonoid, protects the brain against several insults through its antioxidant and anti-inflammatory properties, but its effect on cognitive deficits and brain damage caused by chronic cerebral hypoperfusion remains unknown. Here, we investigated the neuroprotective effect of rutin on cognitive impairments and the potential mechanisms underlying its action in rats with chronic cerebral hypoperfusion.

EXPERIMENTAL APPROACH

We used Sprague-Dawley rats with permanent bilateral common carotid artery occlusion (BCCAO), a well-established model of chronic cerebral hypoperfusion. After rutin treatment for 12 weeks, the neuroprotective effect of rutin in rats was evaluated by behavioural tests, biochemical and histopathological analyses.

KEY RESULTS

BCCAO rats showed marked cognitive deficits, which were improved by rutin treatment. Moreover, BCCAO rats exhibited central cholinergic dysfunction, oxidative damage, inflammatory responses and neuronal damage in the cerebral cortex and hippocampus, compared with sham-operated rats. All these effects were significantly alleviated by treatment with rutin.

CONCLUSION AND IMPLICATIONS

Our results provide new insights into the pharmacological actions of rutin and suggest that rutin has multi-targeted therapeutical potential on cognitive deficits associated with conditions with chronic cerebral hypoperfusion such as vascular dementia and Alzheimer's disease.

Anti-Proliferative Effects of Rutin on OLETF Rat Vascular Smooth Muscle Cells Stimulated by Glucose Variability

PURPOSE

Proliferation of vascular smooth muscle cells (VSMCs) plays a crucial role in atherosclerosis. Rutin is a major representative of the flavonol subclass of flavonoids and has various pharmacological activities. Currently, data are lacking regarding its effects on VSMC proliferation induced by intermittent hyperglycemia. Here, we demonstrate the effects of rutin on VSMC proliferation and migration according to fluctuating glucose levels.

MATERIALS AND METHODS

Primary cultures of male Otsuka Long-Evans Tokushima Fatty (OLETF) rat VSMCs were obtained from enzymatically dissociated rat thoracic aortas. VSMCs were incubated for 72 h with alternating normal (5.5 mmol/L) and high (25.0 mmol/L) glucose media every 12 h. Proliferation and migration of VSMCs, the proliferative molecular pathway [including p44/42 mitogen-activated protein kinases (MAPK), mitogen-activated protein kinase kinase 1/2 (MEK1/2), p38 MAPK, phosphoinositide 3-kinase (PI3K), c-Jun N-terminal protein kinase (JNK), nuclear factor kappa B (NF-κB), and Akt], the migratory pathway (big MAPK 1, BMK1), reactive oxygen species (ROS), and apoptotic pathway were analyzed.

RESULTS

We found enhanced proliferation and migration of VSMCs when cells were incubated in intermittent high glucose conditions, compared to normal glucose. These effects were lowered upon rutin treatment. Intermittent treatment with high glucose for 72 h increased the expression of phospho-p44/42 MAPK (extracellular signal regulated kinase 1/2, ERK1/2), phospho-MEK1/2, phospho-PI3K, phospho-NF-κB, phospho-BMK1, and ROS, compared to treatment with normal glucose. These effects were suppressed by rutin. Phospho-p38 MAPK, phospho-Akt, JNK, and apoptotic pathways [B-cell lymphoma (Bcl)-xL, Bcl-2, phospho-Bad, and caspase-3] were not affected by fluctuations in glucose levels.

CONCLUSION

Fluctuating glucose levels increased proliferation and migration of OLETF rat VSMCs via MAPK (ERK1/2), BMK1, PI3K, and NF-κB pathways. These effects were inhibited by the antioxidant rutin.

Rutin Inhibits Neuroinflammation and Provides Neuroprotection in an Experimental Rat Model of Subarachnoid Hemorrhage, Possibly Through Suppressing the RAGE-NF-κB Inflammatory Signaling Pathway

As is known to all, neuroinflammation plays a vital role in early brain injury pathogenesis following subarachnoid hemorrhage (SAH). It has been shown that rutin have a property of inhibiting inflammation in many kinds of animal models. However, the effect of rutin on neuroinflammation after SAH remains uninvestigated. In this study, we investigated the potential effects of rutin on neuroinflammation and the underlying mechanism in an experimental rat model of SAH performed by endovascular perforation. Adult male SD rats were randomly divided into three groups, including sham group, SAH + vehicle group and SAH + rutin group (50 mg/kg) intraperitoneally (i.p.) administered at 30 min after SAH. After sacrificed at 24 h after SAH, all rats were examined by following tests, including neurologic scores, blood-brain barrier permeability, brain water content and neuronal cell death in cerebral cortex. The level of inflammation in brain was estimated by means of multiple molecules, including RAGE, NF-κB, and inflammation cytokines. Our results indicated that rutin could significantly downregulate the increased level of REGE, NF-κB and inflammatory cytokines in protein level. In addition, rutin could also ameliorate a series of secondary brain injuries such as brain edema, destruction of blood-brain barrier, neurological deficits and neuronal death. This study indicated that rutin administration had a neuroprotective effect in an experimental rat model of SAH, possibly through inhibiting RAGE-NF-κB mediated inflammation signaling pathway.

Rutin phospholipid complexes confer neuro-protection in ischemic-stroke rats

Rutin, a natural flavonol glycoside is known to possess significant radical scavenging properties which might have beneficial effects in cerebral ischemia.

Rutin, a flavonoid phytochemical, ameliorates certain behavioral and electrophysiological alterations and general toxicity of oral arsenic in rats

Arsenic affects large populations and attacks, among others, the nervous system. Waterborne or occupational exposure causes electrophysiological alterations and motor disturbances in humans, and analogous effects were found in animals. Certain phytochemicals may be protective against As-caused damages. In the present study it was investigated whether the flavonoid rutin, applied via the drinking water (2 g/L), ameliorates the effects of arsenic given by gavage (10 mg/kg b.w., in form of NaAsO2) on open field motility, evoked cortical and peripheral electrophysiological activity, and body weight gain in adult male Wistar rats. Body weight gain was significantly reduced from the 4th week of the 6 weeks arsenic treatment and this effect was largely abolished by rutin in the combination treatment group. Rats treated by arsenic alone showed decreased open field motility; latency of the cortical evoked potentials increased and peripheral nerve conduction velocity decreased. These functional alterations were also counteracted by co-administration of rutin, and both the antioxidant and the chelating activity of rutin might have contributed to the ameliorative effect. These results are apparently novel and support the potential role of natural agents in preserving human health in a contaminated environment.