Mitochondrial dysfunction, oxidative stress, ER stress and mitochondria-ER crosstalk alterations in a chemical rat model of Huntington's disease: Potential benefits of bezafibrate.

Redox homeostasis, mitochondrial functions, and mitochondria-endoplasmic reticulum (ER) communication were evaluated in the striatum of rats after 3-nitropropionic acid (3-NP) administration, a recognized chemical model of Huntington's disease (HD). 3-NP impaired redox homeostasis by increasing malondialdehyde levels at 28 days, decreasing glutathione (GSH) concentrations at 21 and 28 days, and the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione S-transferase at 7, 21, and 28 days, catalase at 21 days, and glutathione reductase at 21 and 28 days. Impairment of mitochondrial respiration at 7 and 28 days after 3-NP administration was also observed, as well as reduced activities of succinate dehydrogenase (SDH) and respiratory chain complexes. 3-NP also impaired mitochondrial dynamics and the interactions between ER and mitochondria and induced ER-stress by increasing the levels of mitofusin-1, and of DRP1, VDAC1, Grp75 and Grp78. Synaptophysin levels were augmented at 7 days but reduced at 28 days after 3-NP injection. Finally, bezafibrate prevented 3-NP-induced alterations of the activities of SOD, GPx, SDH and respiratory chain complexes, DCFH oxidation and on the levels of GSH, VDAC1 and synaptophysin. Mitochondrial dysfunction and synaptic disruption may contribute to the pathophysiology of HD and bezafibrate may be considered as an adjuvant therapy for this disorder.

Neuroprotective Potential of Hydroalcoholic Extract of Centella asiatica Against 3-Nitropropionic Acid-Induced Huntington's Like Symptoms in Adult Zebrafish.

Huntington's disease (HD) is an inherited neurodegenerative disease. 3-Nitropropionic acid (3-NP) causes increased reactive oxygen species production and neuroinflammation. Centella asiatica (CA) is a strong antioxidant. The aim of this study is to investigate the effect of hydroalcoholic extract of C. asiatica (HA-CA) on 3-NP-induced HD in adult zebrafish. Adult zebrafish (∼5-6 months old) weighing 470 to 530 mg was used and treated with 3-NP (5 mg/kg intraperitoneal [i.p.]). The animals received HA-CA (80 and 100 mg/L) daily for up to 28 days in water. Tetrabenazine (3 mg/kg i.p.) was used as a standard drug. We have done an open field test (for locomotor activity), a novel tank diving test (for anxiety), and a light and dark tank test (for memory), followed by biochemical analysis (acetyl-cholinesterase [AchEs], nitrite, lipid peroxidation [LPO], and glutathione [GSH]) and histopathology to further confirm memory dysfunctions. 3-NP-treated zebrafish exhibit reductions in body weight, progressive neuronal damage, cognition, and locomotor activity. The HA-CA group significantly reduced the 3-NP-induced increase in LPO, AchEs, and nitrite levels while decreasing GSH levels. Oral administration of HA-CA (80 or 100 mg/L) significantly reduces 3-NP-induced changes in body weight and behaviors, in addition to neuroinflammation in the brain by lowering tumor necrosis factor-α and interleukin-1ß levels. Moreover, HA-CA significantly decreases the 3-NP-induced neuronal damage in the brain. HA-CA ameliorates neurotoxicity and neurobehavioral deficits in 3-NP-induced HD-like symptoms in adult zebrafish.

A Novel Pharmacological Protective Role for Safranal in an Animal Model of Huntington's Disease.

Huntington's disease (HD) is a progressive, neurodegenerative and inherited disease and recent years have witnessed the understanding of the cellular and molecular mechanisms related to HD. Safranal, an organic compound isolated from saffron, has been reported to have anti-apoptotic, anti-inflammatory and antioxidant activity and has studied in chronic and neurodegenerative disease. Therefore, this study was aimed to investigate the effect of safranal on 3-NP induced locomotor activity and biochemical alterations in rats. To this aim, 40 male Wistar rats weighting 250-300 g were divided into 5 groups (n = 8) including sham, 3-NP group (10 mg/kg) as control and treatment groups (3-NP + safranal 0.75, 1.5 and 3 mg/kg) in two weeks duration of treatment. Behavioral/movement assessments in addition to oxidant/antioxidant markers in rat cortex and striatum were evaluated in control and treatment groups. Here, we found that safranal significantly alleviated 3-NP-induced changes of body weight, rotarod activity, number of vacuous chewing movements (VCMs), and locomotor activity. In addition, brain tissue assessments in cortex and striatum revealed that safranal could prevent the elevation of nitrite and malondialdehyde (MDA) levels as well as decrease of superoxide dismutase (SOD), catalase activity and glutathione (GSH) induced by 3-NP. In conclusion our results showed that safranal prevented the motor dysfunction induced by 3-NP in animal model of Huntington's disease. This effect might be due to its modulating effect on oxidants-antioxidant balance.

In vivo imaging of synaptic SV2A protein density in healthy and striatal-lesioned rats with [11C]UCB-J PET.

The number of functionally active synapses provides a measure of neural integrity, with reductions observed in neurodegenerative disorders. [11C]UCB-J binds to synaptic vesicle 2A (SV2A) transmembrane protein located in secretory vesicles. We aimed to assess [11C]UCB-J PET as an in vivo biomarker of regional cerebral synaptic SV2A density in rat lesion models of neurodegeneration. Healthy anesthetized rats had [11C]UCB-J PET and arterial blood sampling. We compared different models describing [11C]UCB-J brain uptake kinetics to determine its regional distribution. Blocking studies were performed with levetiracetam (LEV), an antiepileptic SV2A antagonist. Tracer binding was measured in rodent unilateral acute lesion models of Parkinsonism and Huntington's disease, induced with 6-hydroxydopamine (6-OHDA) and quinolinic acid (QA), respectively. [3H]UCB-J autoradiography was performed in postmortem tissue. Rat brain showed high and fast [11C]UCB-J uptake and washout with up to 80% blockade by LEV. [11C]UCB-J PET showed a 6.2% decrease in ipsilateral striatal SV2A binding after 6-OHDA and 39.3% and 55.1% decreases after moderate and high dose QA confirmed by autoradiography. In conclusion, [11C]UCB-J PET provides a good in vivo marker of synaptic SV2A density which can potentially be followed longitudinally along with synaptic responses to putative neuroprotective agents in models of neurodegeneration.

Rutin and Selenium Co-administration Reverse 3-Nitropropionic Acid-Induced Neurochemical and Molecular Impairments in a Mouse Model of Huntington's Disease.

Systemic administration of 3-nitropropionic acid (3-NPA) is commonly used to induce Huntington's disease (HD)-like symptoms in experimental animals. Here, the potential neuroprotective efficiency of rutin and selenium (RSe) co-administration on 3-NPA-induced HD-like symptoms model in mice was investigated. 3-NPA injection evoked severe alterations in redox status, as indicated via increased striatal malondialdehyde and nitric oxide levels, accompanied by a decrease in levels of antioxidant molecules including glutathione, glutathione peroxidase, glutathione reductase, superoxide dismutase, and catalase. Moreover, 3-NPA potentiated inflammatory status by enhancing the production of interleukin-1ß, tumor necrosis factor-α, and myeloperoxidase activity. Pro-apoptotic cascade was also recorded in the striatum as evidenced through upregulation of cleaved caspase-3 and Bax, and downregulation of Bcl-2. 3-NPA activated astrocytes as indicated by the upregulated glial fibrillary acidic protein and inhibited brain-derived neurotrophic factor. Furthermore, perturbations in cholinergic and monoaminergic systems were observed. RSe provided neuroprotective effects by preventing body weight loss, oxidative stress, neuroinflammation, and the apoptotic cascade. RSe inhibited the activation of astrocytes, increased brain-derived neurotrophic factor, and improved cholinergic and monoaminergic transmission following 3-NPA intoxication. Taken together, RSe co-administration may prevent or delay the progression of HD and its associated impairments through its antioxidant, anti-inflammatory, anti-apoptotic, and neuromodulatory effects.

Striatal mitochondria response to 3-nitropropionic acid and fish oil treatment.

BACKGROUND: Mitochondrial dysfunction is involved in neurodegenerative diseases, such as Huntington's disease (HD). 3-Nitropropionic acid (3-NP) is a mitochondrial toxin that specifically inhibits complex II of the electron transport chain (ETC) and is used to generate an experimental model of HD. OBJECTIVE: To study the effect of fish liver oil (FO) over the mitochondrial dysfunction induced via partial ETC inhibition by 3-NP. METHODS: This study was performed in rats and consisted of two phases: (i) administration of increasing doses of 3-NP and (ii) administration of FO for 14 days before to 3-NP. The rats' exploratory activity; complex I, II, III, and IV activities; and rearing behavior were observed. Additionally, the number of TUNEL-positive cells and various mitochondrial parameters, including oxygen consumption, transmembrane potential, adenosine triphosphate synthesis, and ETC activity, were measured. RESULTS: We observed that FO exerted a protective effect against the 3-NP-induced toxicity, although complex II inhibition still occurred. Instead, this effect was related to strengthened mitochondrial complex III and IV activities. DISCUSSION: Our results show that FO exerts a beneficial prophylactic effect against mitochondrial damage. Elucidating the mechanisms linking the effects of FO with its prevention of neurodegeneration could be the key to developing recommendations for FO consumption in neurological pathologies.

Neuroprotective effect of solanesol against 3-nitropropionic acid-induced Huntington's disease-like behavioral, biochemical, and cellular alterations: Restoration of coenzyme-Q10-mediated mitochondrial dysfunction.

OBJECTIVE: The aim of the present study was to evaluate the solanesol (SNL)-mediated coenzyme-Q10 restoration to ameliorate 3-nitropropionic (3-NP)-induced behavioral, biochemical, and histological changes which resemble Huntington's disease (HD)-like symptoms in men. MATERIALS AND METHODS: Various behavioral and biochemical parameters were carried out to evaluate the activity of SNL on 3-NP-treated rats. To determine the therapeutic significance of SNL on HD, different behavioral tests such as memory task, locomotor activity, grip strength, and beam cross and some biochemical test along with histopathological findings were done. RESULTS: Chronic 3-NP, 10 mg/kg i.p., caused physical and mental abnormalities in animals, including memory impairment, weak grip strength, abnormal posture, and cognitive deficit. Biochemical analysis of brain homogenate in 3-NP-treated rats showed altered mitochondrial complexes, oxidative stress, and elevated lipid biomarkers. Neurohistological alterations of hippocampus, basal ganglia, and cerebral cortex of 3-NP-treated rats exhibit severe neuronal space, irregular damaged cells, and dense pyknotic nuclei-associated marked focal diffused gliosis. SNL administered for 15 days significantly improved motor performance and cognitive behavior task and restored the histopathological changes. Further, SNL treatment significantly improved mitochondrial complexes such as coenzyme-Q10 enzyme activity and attenuated inflammatory and oxidative damage of rat brain. CONCLUSION: In the present research work, SNL (5, 10, and 15 mg/kg p.o.) provided notable neuroprotective effect, which was confirmed by behavioral paradigms and biochemical test. It restored the behavioral and biochemical alteration caused by 3-NP and confirmed the strong neuroprotective mechanism of SNL in 3-NP-intoxicated memory and cognitive abnormalities.

Effect of Praeruptorin C on 3-nitropropionic acid induced Huntington's disease-like symptoms in mice.

Huntington's disease (HD) is an autosomal dominant inherited disease characterized by movement, psychiatric, and cognitive disorders. Previous research suggests that Praeruptorin C (Pra-C), an effective component in the root of Peucedanum praeruptorum dunn, a traditional Chinese medicine, may function in neuroprotection. The present study was conducted to evaluate the effectiveness of Pra-C in the treatment of HD-like symptoms in a 3-nitropropionic acid (3-NP) mouse model, and to explore the possible mechanism of the drug's activity. We treated 3-NP-injected mice with two different doses of Pra-C (1.5 and 3.0mg/kg) for 3 days. Motor behavior was tested using the open field test (OFT) and rotarod test, while psychiatric symptoms were tested using the forced swimming test (FST) and tail suspension test (TST). We found that Pra-C alleviated the motor deficits and depression-like behavior in the 3-NP-treated mice, and protected neurons from excitotoxicity. Western blot analysis revealed that Pra-C upregulated BDNF, DARPP32, and huntingtin protein in the striatum of 3-NP mice. These results taken together suggest that Pra-C may have therapeutic potential with respect to the movement, psychiatric, and cognitive symptoms of HD.

Neuroprotective Activity of Curcumin in Combination with Piperine against Quinolinic Acid Induced Neurodegeneration in Rats.

AIM: Quinolinic acid (QA) is an excitotoxin that induces Huntington's-like symptoms in animals and humans. Curcumin (CMN) is a well-known antioxidant but the major problem is its bioavailability. Therefore, the present study was designed to investigate the effect of CMN in the presence of piperine against QA-induced excitotoxic cell death in rats. MATERIAL AND METHODS: QA was administered intrastriatally at a dose of 200 nmol/2 µl saline, bilaterally. CMN (25 and 50 mg/kg/day, p.o.) and combination of CMN (25 mg/kg/day, p.o.) and with piperine (2.5 mg/kg/day, p.o.) was administered daily for the next 21 days. Body weight and behavioral parameters were observed on 1st, 7th, 14th and 21st day. On the 22nd day, animals were sacrificed and striatum was isolated for biochemical (LPO, nitrite and GSH), neuroinflammatory (interleukin (IL)-1ß, IL-6 and TNF-α) and neurochemical (dopamine, norepinephrine, GABA, glutamate, 5-HT, 3,4-dihydroxyphenylacetic acid and homovanillic acid) estimation. RESULTS: CMN treatment showed beneficial effect against QA-induced motor deficit, biochemical and neurochemical abnormalities in rats. Combination of piperine (2.5 mg/kg/day, p.o.) with CMN (25 mg/kg/day, p.o.) significantly enhanced its protective effect as compared to treatment with CMN alone. CONCLUSION: This study has revealed that the combination of CMN and piperine showed strong antioxidant and protective effect against QA-induced behavioral and neurological alteration in rats.

Genistein improves sensorimotor gating: Mechanisms related to its neuroprotective effects on the striatum.

Huntington's disease (HD) is a neurodegenerative disorder, characterized by selective atrophy in the striatum, particularly the medium spiny GABAergic efferent neurons. This results in striatal sensorimotor gating deficits. Systemic administration of 3-nitropropionic acid (3-NPA) produces selective lesions mimicking those of HD. Males were found to be more susceptible to 3-NPA-induced neurotoxicity than females, suggesting neuroprotective effects of estrogens. Phytoestrogens, including genistein, are good estrogenic alternatives that keep their beneficial effects on non-reproductive organs and lack the potential hazardous side effects. The current study was designed to investigate the potential beneficial effects of genistein in 3-NPA-induced HD in ovariectomized rats. Results showed that 3-NPA (20 mg/kg) administration caused significant disruption of the rats' locomotor activity and prepulse inhibition. In addition, it decreased striatal ATP levels and increased oxidative stress, inflammatory and apoptotic markers with striatal focal hemorrhage and gliosis. Pretreatment with 17ß-estradiol (2.5 mg/kg) or genistein (20 mg/kg) led to a significant improvement of behavioral parameters, increased ATP production, decreased oxidative stress, attenuated inflammation and apoptosis. Therefore, this study suggests potential neuroprotective effects of genistein in ovariectomized rats challenged with 3-NPA.

Sub-chronic copper pretreatment reduces oxidative damage in an experimental Huntington's disease model.

Quinolinic acid (QUIN) striatal injection in rat reproduces the main neurochemical features of Huntington's disease (HD), including oxidative damage. In this study, we evaluated the effect of a copper (Cu) supplement in drinking water (90 ppm Cu, 28 days) on the QUIN-induced HD model in the rat. Copper exposure caused no signs of liver toxicity; however, it produced significant Cu accumulation in striatum. It is noteworthy that QUIN also caused increased striatal Cu content; when the supplement was administered to animals with QUIN-injury, an even higher metal striatal accumulation was observed. Cu pre-treatment preserved striatal gamma-aminobutyric acid (GABA) content, which was reduced by QUIN intrastriatal injection. Similarly, apomorphine-induced circling behavior was reduced in Cu-pretreated QUIN-damaged rats. Metal supplement in drinking water prevented both lipid peroxidation and reactive oxygen species (ROS) formation caused by QUIN in striatum. In Cu-treated groups, superoxide dismutase-1 (SOD1) activity showed a significant increase, while SOD2 activity was slightly enhanced. Although the pathophysiological role for higher Cu levels in patients with HD and in experimental models of the disease is not fully understood, results in the present study suggest that Cu oral intake stimulates anti-oxidant defenses, an effect that may be a potential factor for reducing the progression of HD.

Curcumin nanoparticles attenuate neurochemical and neurobehavioral deficits in experimental model of Huntington's disease.

Till date, an exact causative pathway responsible for neurodegeneration in Huntington's disease (HD) remains elusive; however, mitochondrial dysfunction appears to play an important role in HD pathogenesis. Therefore, strategies to attenuate mitochondrial impairments could provide a potential therapeutic intervention. In the present study, we used curcumin encapsulated solid lipid nanoparticles (C-SLNs) to ameliorate 3-nitropropionic acid (3-NP)-induced HD in rats. Results of MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) assay and succinate dehydrogenase (SDH) staining of striatum revealed a marked decrease in Complex II activity. However, C-SLN-treated animals showed significant increase in the activity of mitochondrial complexes and cytochrome levels. C-SLNs also restored the glutathione levels and superoxide dismutase activity. Moreover, significant reduction in mitochondrial swelling, lipid peroxidation, protein carbonyls and reactive oxygen species was observed in rats treated with C-SLNs. Quantitative PCR and Western blot results revealed the activation of nuclear factor-erythroid 2 antioxidant pathway after C-SLNs administration in 3-NP-treated animals. In addition, C-SLN-treated rats showed significant improvement in neuromotor coordination when compared with 3-NP-treated rats. Thus, the results of this study suggest that C-SLNs administration might be a promising therapeutic intervention to ameliorate mitochondrial dysfunctions in HD.

Neuroprotective effect of lutein against 3-nitropropionic acid-induced Huntington's disease-like symptoms: possible behavioral, biochemical, and cellular alterations.

3-Nitropropionic acid (3-NP) induces cellular energy deficit and oxidative stress-related neurotoxicity via an irreversible inhibition of mitochondrial complex II enzyme, succinate dehydrogenase. Huntington's disease (HD) is a neurological disorder characterized by cognitive and motor dysfunctions. Lutein is a well-known antioxidant used in the management of oxidative stress related diseases. Clinical trials have supported the beneficial effect of lutein in Alzheimer's disease. The present study was designed to explore possible neuroprotective effects of lutein on 3-NP-induced mitochondrial dysfunction and oxidative stress. Systemic administration of 3-NP (25 mg/kg intraperitoneally [i.p.] for 4 consecutive days) caused loss of body weight and neurobehavioral deficits by hind-limb impairment (Narrow Beam test), motor coordination (locomotor activity) and memory dysfunction (Morris water maze and Elevated Plus maze performance). Biochemical analysis revealed significant increase in lipid peroxidation, nitrite concentration, reduced gutathione levels, and acetyl cholinesterase levels and depleted catalase activities in rat brain. The activities of mitochondrial complexes (I, II, IV, and MTT assay) were found to be significantly lowered in brain mitochondria. Daily lutein (50 or 100 mg/kg orally [p.o.]) administration for 14 days significantly improved body weight, neurobehavioral alterations and attenuated oxidative stress and improved mitochondrial enzymes complex activities of rat brain. Histopathological examination further affirmed the neuroprotective effect of lutein on 3-NP induced pathological lesions. The present study indicates that lutein is a promising candidate for the management of HD and related conditions.

Probucol increases striatal glutathione peroxidase activity and protects against 3-nitropropionic acid-induced pro-oxidative damage in rats.

Huntington's disease (HD) is an autosomal dominantly inherited neurodegenerative disease characterized by symptoms attributable to the death of striatal and cortical neurons. The molecular mechanisms mediating neuronal death in HD involve oxidative stress and mitochondrial dysfunction. Administration of 3-nitropropionic acid (3-NP), an irreversible inhibitor of the mitochondrial enzyme succinate dehydrogenase, in rodents has been proposed as a useful experimental model of HD. This study evaluated the effects of probucol, a lipid-lowering agent with anti-inflammatory and antioxidant properties, on the biochemical parameters related to oxidative stress, as well as on the behavioral parameters related to motor function in an in vivo HD model based on 3-NP intoxication in rats. Animals were treated with 3.5 mg/kg of probucol in drinking water daily for 2 months and, subsequently, received 3-NP (25 mg/kg i.p.) once a day for 6 days. At the end of the treatments, 3-NP-treated animals showed a significant decrease in body weight, which corresponded with impairment on motor ability, inhibition of mitochondrial complex II activity and oxidative stress in the striatum. Probucol, which did not rescue complex II inhibition, protected against behavioral and striatal biochemical changes induced by 3-NP, attenuating 3-NP-induced motor impairments and striatal oxidative stress. Importantly, probucol was able to increase activity of glutathione peroxidase (GPx), an enzyme important in mediating the detoxification of peroxides in the central nervous system. The major finding of this study was that probucol protected against 3-NP-induced behavioral and striatal biochemical changes without affecting 3-NP-induced mitochondrial complex II inhibition, indicating that long-term probucol treatment resulted in an increased resistance against neurotoxic events (i.e., increased oxidative damage) secondary to mitochondrial dysfunction. These data appeared to be of great relevance when extrapolated to human neurodegenerative processes involving mitochondrial dysfunction and indicates that GPx is an important molecular target involved in the beneficial effects of probucol.

Protective effect of Calendula officinalis Linn. flowers against 3-nitropropionic acid induced experimental Huntington's disease in rats.

Oxidative stress (OS) and nitric oxide mechanisms have been recently proposed in 3-nitropropionic acid (3-NP)-induced neurotoxicity. The compounds, having antioxidant, anti-inflammatory and estrogenic effects, have been suggested for neuroprotection in different experimental models. Calendula officinalis Linn. flower extract (COE) is known for its potent antioxidant, anti-inflammatory, estrogenic and neuroprotective activities. Hence, the present study was designed to evaluate the neuroprotective effect of COE on 3-NP-induced neurotoxicity in rats by observing behavioral changes, OS and striatal damage in rat brain. Adult female Wistar rats were pretreated with vehicle or COE (100 and 200 mg/kg) for 7 days, followed by cotreatment with 3-NP (15 mg/kg, intraperitoneally) for the next 7 days. At the end of the treatment schedule, rats were evaluated for alterations in sensory motor functions and short-term memory. Animals were sacrificed and brain homogenates were used for the estimation of lipid peroxidation (LPO), glutathione, total thiols, glutathione S-transferase, catalase and nitrite. A set of brain slices was used for the evaluation of neuronal damage in the striatal region of the brain. 3-NP caused significant alterations in animal behavior, oxidative defense system evidenced by raised levels of LPO and nitrite concentration, and depletion of antioxidant levels. It also produced a loss of neuronal cells in the striatal region. Treatment with COE significantly attenuated behavioral alterations, oxidative damage and striatal neuronal loss in 3-NP-treated animals. The present study shows that COE is protective against 3-NP-induced neurotoxicity in rats. The antioxidant, anti-inflammatory and estrogenic properties of COE may be responsible for its neuroprotective action.

Quercetin supplementation is effective in improving mitochondrial dysfunctions induced by 3-nitropropionic acid: implications in Huntington's disease.

The study was designed to investigate the beneficial effect of quercetin supplementation in 3-nitropropionic acid (3-NP) induced model of Huntington's disease (HD). HD was induced in rats by administering sub-chronic dose of 3-NP, intraperitoneally, twice daily for 17days. Quercetin was supplemented at a dose of 25mg/kg body weight by oral gavage for 21days. At the end of treatment, mitochondrial bioenergetics, mitochondrial swelling, oxidative stress, neurobehavioral deficits and histopathological changes were analyzed. Quercetin supplementation was able to reverse 3-NP induced inhibition of respiratory chain complexes, restore ATP levels, attenuate mitochondrial oxidative stress in terms of lipid peroxidation and prevent mitochondrial swelling. Quercetin administration also restored the activities of superoxide dismutase and catalase along with thiol content in 3-NP treated animals. Beneficial effect of quercetin administration was observed on 3-NP induced motor deficits analyzed by narrow beam walk and footprint analysis. Histopathological analysis of 3-NP treated rats revealed pyknotic nuclei and astrogliosis in striatum, which were reduced or absent in quercetin supplemented animals. Altogether, our results show that quercetin supplementation to 3-NP induced HD animals ameliorated mitochondrial dysfunctions, oxidative stress and neurobehavioral deficits in rats showing potential of this flavonoid in maintaining mitochondrial functions, suggesting a putative role of quercetin in HD management.

Sativex-like combination of phytocannabinoids is neuroprotective in malonate-lesioned rats, an inflammatory model of Huntington's disease: role of CB1 and CB2 receptors.

We have investigated whether a 1:1 combination of botanical extracts enriched in either Δ(9)-tetrahydrocannabinol (Δ(9)-THC) or cannabidiol (CBD), which are the main constituents of the cannabis-based medicine Sativex, is neuroprotective in Huntington's disease (HD), using an experimental model of this disease generated by unilateral lesions of the striatum with the mitochondrial complex II inhibitor malonate. This toxin damages striatal neurons by mechanisms that primarily involve apoptosis and microglial activation. We monitored the extent of this damage and the possible preservation of the striatal parenchyma by treatment with a Sativex-like combination of phytocannabinoids using different histological and biochemical markers. Results were as follows: (i) malonate increased the volume of edema measured by in vivo NMR imaging and the Sativex-like combination of phytocannabinoids partially reduced this increase; (ii) malonate reduced the number of Nissl-stained cells, while enhancing the number of degenerating cells stained with FluoroJade-B, and the Sativex-like combination of phytocannabinoids reversed both effects; (iii) malonate caused a strong glial activation (i.e., reactive microglia labeled with Iba-1, and astrogliosis labeled with GFAP) and the Sativex-like combination of phytocannabinoids attenuated both responses; and (iv) malonate increased the expression of inducible nitric oxide synthase and the neurotrophin IGF-1, and both responses were attenuated after the treatment with the Sativex-like combination of phytocannabinoids. We also wanted to establish whether targets within the endocannabinoid system (i.e., CB(1) and CB(2) receptors) are involved in the beneficial effects induced in this model by the Sativex-like combination of phytocannabinoids. This we did using selective antagonists for both receptor types (i.e., SR141716 and AM630) combined with the Sativex-like phytocannabinoid combination. Our results indicated that the effects of this combination are blocked by these antagonists and hence that they do result from an activation of both CB(1) and CB(2) receptors. In summary, this study provides preclinical evidence in support of a beneficial effect of the cannabis-based medicine Sativex as a neuroprotective agent capable of delaying signs of disease progression in a proinflammatory model of HD, which adds to previous data obtained in models priming oxidative mechanisms of striatal injury. However, the interest here is that, in contrast with these previous data, we have now obtained evidence that both CB(1) and CB(2) receptors appear to be involved in the effects produced by a Sativex-like phytocannabinoid combination, thus stressing the broad-spectrum properties of Sativex that may combine activity at the CB(1) and/or CB(2) receptors with cannabinoid receptor-independent actions.

The effect of Ginkgo biloba extract on 3-nitropropionic acid-induced neurotoxicity in rats.

3-Nitropropionic acid (3-NP), an irreversible inhibitor of succinate dehydrogenase enzyme (SDH), induces neurodegeneration similar to that observed in Huntington's disease (HD). Reduction of prepulse inhibition (PPI) of acoustic startle response, locomotor hypoactivity, bilateral striatal lesions as well as brain oxidative stress are major features of HD. The present study was designed to investigate neuroprotective effect of Ginkgo biloba extract (EGb 761) on 3-NP induced neurobehavioral changes and striatal lesions. Rats administered 3-NP (20mg/kg, s.c.) for five consecutive days exhibited PPI deficits and locomotor hypoactivity whereas, pretreatment of animals with EGb 761 (100mg/kg, i.p. for 15 days) ahead of and during the induction of HD by 3-NP (20mg/kg for 5 days starting at day 8) ameliorated 3-NP-induced neurobehavioral deficits. Administration of 3-NP increased the level of striatal malondialdehyde (MDA). This effect was prevented in animals pre-treated with EGb 761. Changes in the level of apoptotic regulatory gene expressions, following 3-NP treatment, were demonstrated as both an up-regulation and a down-regulation of the expression levels of striatal Bax and Bcl-xl genes, respectively. In addition, an up-regulation of the expression level of striatal glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was also observed. Pre-treatment with EGb 761 caused a down-regulation in striatal GAPDH and Bax together with an up-regulation of striatal Bcl-xl expression level as compared to the 3-NP treated group. Histochemical examination of striatal tissue showed that EGb 761 significantly prevented 3-NP induced inhibition of SDH activity. Histopathological examination further affirmed the neuroprotective effect of EGb 761 against 3-NP toxicity. Taken together, these results suggest that EGb 761 has a neuroprotective role in the current HD paradigm, which may be related to improvement of energy metabolism, antioxidant properties and antiapoptotic effects.

Olive oil reduces oxidative damage in a 3-nitropropionic acid-induced Huntington's disease-like rat model.

Free radicals contribute to altered neuronal functions in neurodegenerative diseases and brain aging, by producing lipid- and other molecule-dependent modifications. The Mediterranean diet has been associated with a reduced risk of neurodegenerative disease. This study sought to verify whether extra-virgin olive oil (EVOO) exerted a brain antioxidant effect, protecting the brain against the oxidative stress caused by 3-nitropropionic acid (3NP). 3NP was administered intraperitoneally (i.p.) at a dose of 20 mg/kg body weight over four consecutive days. EVOO (representing 10% of calorie intake in the total standard daily diet of rats) and hydroxytyrosol (HT; 2.5 mg/kg body weight) were administered for 14 days. In all studied samples, 3NP caused a rise in lipid peroxides (LPO) and a reduction in glutathione (GSH) content. While the results showed that EVOO and HT reduces lipid peroxidation product levels and blocks the GSH depletion prompted by 3NP in both striatum and rest of the brain in Wistar rats. In addition, EVOO blocks and reverses the effect of 3NP on succinate dehydrogenase activity. In brief, the data obtained indicate that EVOO and HT act as a powerful brain antioxidant.

Metabolic profiling of 3-nitropropionic acid early-stage Huntington's disease rat model using gas chromatography time-of-flight mass spectrometry.

3-Nitropropionic acid (3-NP), a potent irreversible inhibitor of mitochondrial complex II enzyme, leads to mitochondrial dysfunction and oxidative stress in Huntington's disease (HD) rat model. In this study, biochemical assays were used to demonstrate the presence of oxidative stress and mitochondrial dysfunction in 3-NP early stage HD rat models. Gas chromatography time-of-flight mass spectrometry (GC/TOFMS) was applied to analyze metabolites in brain and plasma of 3-NP-treated and vehicle-dosed rats. The orthogonal partial least-squares discriminant analysis (OPLS-DA) model generated using brain metabolic profiles robustly differentiated the 3-NP early stage HD rat model from the control. Metabonomic characterization of the 3-NP HD rat model facilitated the detection of biomarkers that define the physiopathological phenotype of early stage HD and elucidated the treatment effect of galantamine. Brain marker metabolites that were identified based on the OPLS-DA model were associated with altered glutathione metabolism, oxidative stress, and impaired energy metabolism. The treatment effect of galantamine in early stage HD could not be concluded mechanistically using the brain metabotype. Our study confirmed that GC/TOFMS is a strategic and complementary platform for the metabonomic characterization of 3-NP induced neurotoxicity in the early stage HD rat model.