Narrow Beam Walk Research Articles

Costunolide ameliorates rotenone-induced Parkinson's disease in rat model via activation of SIRT-1/p-AMPK cascade and suppression of IL-6/STAT3 axis

Costunolide (COST), a sesquiterpene lactone, has demonstrated promising potential in molecular docking studies targeting key proteins associated with Parkinson's disease (PD), particularly AMP-activated protein kinase (AMPK) and sirtuin-1 (SIRT1). Building on these preliminary findings, this study was designed to explore the in vivo neuroprotective effects of COST in a rotenone-induced PD model, aiming to substantiate its therapeutic efficacy. The evaluation focused on motor function, oxidative stress markers, neuroinflammatory indicators, and the balance between autophagy and apoptosis, alongside histopathological examination.Treatment with COST displayed an enhancement in motor performance, as observed by improved results in both the open-field and narrow beam walk tests. Concurrently, COST preserved dopaminergic neurons in the substantia nigra and boosted tyrosine hydroxylase immunoreactivity. Furthermore, COST reduced oxidative stress status via increasing SIRT-1 and PGC-1α content. Notably, COST suppressed neuroinflammation by inhibiting the IL-6R/STAT3/NFκBp65 /IL-6 signaling pathway. Additionally, COST stimulated autophagy via the activation of p-AMPK/ULK1/Beclin-1 cascade, facilitating the removal misfolded protein, α-synuclein. COST also reduced apoptosis by increasing Bcl-2 and decreasing Bax levels. In conclusion, COST exhibited promising neuroprotective effects against rotenone-induced PD in a rat model. This protection is mediated through the activation of the SIRT1/PGC-1α and p-AMPK/ULK1/Beclin-1 pathways, alongside the inhibition of the IL-6R/STAT3/NFκBp65 axis. Collectively, these mechanisms attenuated oxidative stress and neuroinflammation while restoring the balance between apoptosis and autophagy, positioning COST as a potential therapeutic candidate for Parkinson's disease.

Saroglitazar, a PPAR α/γ agonist alleviates 3-Nitropropionic acid induced neurotoxicity in rats: Unveiling the underlying mechanisms

Saroglitazar (SGZ), a peroxisomal proliferated activated receptor α/γ agonist showed neuroprotective effects in various neurodegenerative disorders like Alzheimer’s and Parkinson’s. However, no studies were performed on Huntington’s, so the goal of the current study is to examine the effect of SGZ on Huntington’s disease like symptoms induced by 3-Nitropropionic acid. In this protocol, twenty-four rats were divided into four groups, each group consisting of 6 animals. Group 1: The control group received 1 % CMC 10 mg/kg, p.o. for 14 days. Groups 2, 3, and 4 received 3-NP 15 mg/kg, i.p. from Day 1 to Day 7. Groups 3 and 4 received SGZ 5 mg/kg, p.o. and 10 mg/kg, p.o. respectively once daily from day 1 to day 14. Various behavioral tests like OFT, rotarod, hanging wire, narrow beam walk, MWM, and Y-maze were performed. On day-15, the animals were euthanised by cervical dislocation and brain sample were isolated for biochemical and histopathological analysis. Administration of 3-NP showed a significant decrease in motor coordination and cognitive function. Furthermore, 3-NP altered the activity of acetylcholinesterase, anti-oxidant enzymes, Nrf-2, NF-κB, BDNF, CREB levels, and histological features. However, treatment with SGZ showed ameliorative effects in the 3-NP induced neurotoxicity via PPAR α/γ pathway by reducing motor dysfunction, memory impairment, cholinesterase levels, oxidative stress, neuroinflammation. It also enhanced the levels of Nrf-2, BDNF, and CREB expression and improved histological features. In conclusion, treatment with Saroglitazar attenuated Huntington’s disease-like symptoms in rats which are induced by 3-NP via activation of PPAR α/γ pathway.

6-shogaol against 3-Nitropropionic acid-induced Huntington's disease in rodents: Based on molecular docking/targeting pro-inflammatory cytokines/NF-κB-BDNF-Nrf2 pathway.

Huntington's disease (HD) is an extremely harmful autosomal inherited neurodegenerative disease. Motor dysfunction, mental disorder, and cognitive deficits are the characteristic features of this disease. The current study examined whether 6-shogaol has a protective effect against 3-Nitropropionic Acid (3-NPA)-induced HD in rats. A total of thirty male Wistar rats received 6-shogaol (10 and 20 mg/kg, per oral) an hour before injection of 3-NPA (10 mg/kg i.p.) for 15 days. Behavioral tests were performed, including narrow beam walk, rotarod test, and grip strength test. Biochemical tests promoting oxidative stress were evaluated [superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT) and malondialdehyde (MDA)], including changes to neurotransmitters serotonin (5-HT), dopamine (DA), norepinephrine (NE), homovanillic acid (HVA), (3,4-dihydroxyphenylacetic acid (DOPAC), γ-aminobutyric acid (GABA), and 5-hydroxy indole acetic acid (5-HIAA), nuclear factor kappa-B (NF-κB), tumor necrosis factor-α (TNF-α), interleukins-1β (IL-1β), IL-6, brain-derived neurotrophic factor (BDNF), and nuclear factor erythroid 2-related factor 2 (Nrf2). The 6-shogaol was docked to the active site of TNF-α (2AZ5), NF-κB (1SVC), BDNF) [1B8M], and Nrf2 [5FZN] proteins using AutoDock tools. The 6-shogaol group significantly improved behavioral activity over the 3-NPA-injected control rats. Moreover, 3-NPA-induced significantly altered neurotransmitters, biochemical and neuroinflammatory indices, which could efficiently be reversed by 6-shogaol. The 6-shogaol showed favorable negative binding energies at -9.271 (BDNF) kcal/mol. The present investigation demonstrated the neuroprotective effects of 6-shogaol in an experimental animal paradigm against 3-NPA-induced HD in rats. The suggested mechanism is supported by immunohistochemical analysis and western blots, although more research is necessary for definite confirmation.

Contralesional Anodal Transcranial Direct Current Stimulation Promotes Intact Corticospinal Tract Axonal Sprouting and Functional Recovery After Traumatic Brain Injury in Mice

Background Anodal transcranial direct current stimulation (AtDCS), a neuromodulatory technique, has been applied to treat traumatic brain injury (TBI) in patients and was reported to promote functional improvement. We evaluated the effect of contralesional AtDCS on axonal sprouting of the intact corticospinal tract (CST) and the underlying mechanism in a TBI mouse model to provide more preclinical evidence for the use of AtDCS to treat TBI. Methods TBI was induced in mice by a contusion device. Then, the mice were subjected to contralesional AtDCS 5 days per week followed by a 2-day interval for 7 weeks. After AtDCS, motor function was evaluated by the irregular ladder walking, narrow beam walking, and open field tests. CST sprouting was assessed by anterograde and retrograde labeling of corticospinal neurons (CSNs), and the effect of AtDCS was further validated by pharmacogenetic inhibition of axonal sprouting using clozapine-N-oxide (CNO). Results TBI resulted in damage to the ipsilesional cortex, while the contralesional CST remained intact. AtDCS improved the skilled motor functions of the impaired hindlimb in TBI mice by promoting CST axon sprouting, specifically from the intact hemicord to the denervated hemicord. Furthermore, electrical stimulation of CSNs significantly increased the excitability of neurons and thus activated the mechanistic target of rapamycin (mTOR) pathway. Conclusions Contralesional AtDCS improved skilled motor following TBI, partly by promoting axonal sprouting through increased neuronal activity and thus activation of the mTOR pathway.

Levothyroxine attenuates behavioral impairment and improves oxidative stress and histological alteration 3-nitropropionic acid induced experimental Huntington’s disease in rats

Huntington’s disease (HD) is a neurodegenerative disorder characterized by degeneration of the striatum; it results in oxidative stress and motor deficits. Thyroid hormones regulate oxidative metabolism. In the present study, we evaluated the effect of administration of levothyroxine (LT-4) on neurobehavioral, oxidative stress, and histological changes in a rat model of HD. Forty-eight Wistar male rats were divided into the following six groups (n = 8): Group 1 (control) received physiological saline intraperitoneally (ip). Groups 2 and 3 received L-T4,30 and L-T4100 (μg/kg, ip, respectively) daily for 7 days. Group 4 (HD) received 3-nitropropionic acid (3-NP) (25 mg/kg, ip) daily for 7 days. Groups 5 and 6 received L-T4,30 and L-T4100 (μg/kg, ip, respectively) 30 min after 3-NP (25 mg/kg, ip) injection for the same duration. On the 8th day, behavioral parameters were evaluated with the Rotarod, Narrow beam walk, and Limb withdrawal tests. Oxidative markers such as Malondialdehyde (MDA) and Glutathione (GSH) levels and Superoxide dismutase (SOD) activity, in striatum tissue were measured. Moreover, striatum tissues were analyzed by Hematoxylin-eosin staining for histological alterations. We found that 3-NP administration caused motor incoordination and induced oxidative stress increased but reduced free radical scavenging. Also, increased amounts of lipid peroxides caused striatal damage as shown by histopathological evaluation. Administration of L-T4 led to increased falling time in the Rotarod, but reduced the time taken in Narrow beam walking and Limb withdrawal test. Furthermore, L-T4 increased antioxidant activity, decreased lipid peroxidation and ameliorated 3-NP-induced degeneration in neurons.

Effect of Bacille-Calmette-Guerin vaccine against rotenone-induced Parkinson's disease: Role of neuroinflammation and neurotransmitters.

Parkinson's disease (PD) is an extrapyramidal movement disorder associated with a hypokinetic condition generated by impairment in dopaminergic neuronal viability in the nigrostriatal region of the brain. Current medications can only provide symptomatic management; to date, no permanent cure is available. To compensate for this lacuna, researchers are gaining interest in antigen-based therapy, and Bacille-Calmette-Guerin (BCG) is one of the vaccineswith a high safety margin that acts by stimulating immunoreactive T-cells in the CNS and reducing expression of pro-inflammatory cytokines including interleukin (IL)-1β and tumor necrotic factor (TNF-α) to produce neuroprotection. A previous study reported that BCG exerts a neuroprotective effect against several neurodegenerative disorders, such as Alzheimer's disease. The objective of this study is to explore the neuroprotective effect of the BCG vaccine against the rotenone model of PD. Rotenone (1.5 mg/kg, s.c) for 28 days, and BCG vaccine (2 × 107 cfu, i.p) single dose was injected to rats, and behavioral assessments were performed on the 21st and 28th day. On the 29th day, rats were sacrificed, and brains were isolated for biochemical and neurochemical estimation. BCG vaccine significantly restored rotenone-induced motor deficits (open field test, narrow beam walk, and rotarod), biochemical levels (GSH, SOD, catalase, MDA, and nitrite), neurotransmitters (dopamine, 5-hydroxy tryptamine, norepinephrine, 3,4-dihydroxyphenylacetic acid, hemovanillic acid, and 5-hydroxy indoleacetic acid), and levels of inflammatory cytokines (IL-1β and TNF-α) in the striatum. It also prevents histopathological changes by reducing eosinophilic lesions in the striatum. From the results, we conclude that BCG vaccine showed neuroprotection through antioxidant and anti-inflammatory effect. Thus, in the future, it can be used as a neuroprotective agent for other neurological disorders, including PD.

Neuroprotective potential of carbamide forte on LPS‐induced experimental PD

AbstractBackgroundParkinson’s disease is a second most common age‐related neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta region of the midbrain. Increased oxidative stress and inflammation with decreased activity of glutathione peroxidase, superoxide dismutase (SOD), and catalase has been observed in PD patients. Carbamide Forte Brain and Memory Support is blend of 9 herbal brain‐enhancing ingredients to boost short term cognitive function and long‐term brain health and thus expected to be beneficial in cognition and movement disorder.MethodAdult male/female Sprague Dawley rats were ICV injected with LPS at a dose of 0.2 mg/kg body weight into substantia nigra pars compacta with the help of stereotaxic apparatus. Carbamide Forte was administered per orally at 80 and 160 mg/kg body weight, 4 days after to LPS infusion.ResultInfusion of single ICV‐LPS produced significantly decreased in body weight, locomotor activity, motor coordination, antioxidant defense enzymes and significantly increased oxidative stress markers in the striatum. Chronic administration of carbamide forte (for 21days) significantly attenuated LPS induced movement disabilities in Narrow beam walk, Horizontal ladder beam walk test, OFT and also significantly reduce the oxidative‐nitrosative stress and antioxidants enzymesas evidence by decrease in malondialdehyde and nitrite levels and restored the reduced glutathione level in rats & neuroprotective potential of CF with morphological changes seen in our histological assessment. The observed result of the present study is indicative of the therapeutic potential of Carbamide Forte in PD.ConclusionIt could be concluded that the observed neuroprotective effect of Carbamide Forte may be due to antioxidant and neuroprotective potential.

Six Minutes Walking in Polio Survivors: Effects on Fatigue and Walking Adaptability

To investigate whether 6-min walking is fatiguing for polio survivors, and how fatigue influences their normal and adaptive walking. Cross-sectional study. Polio survivors (n = 23) with ≥ 1 fall and/or fear of falling reported in the previous year and healthy individuals (n = 11). Participants performed 1 normal-walk test and 2 walking-adaptability tests (target stepping and narrow-beam walking) on an instrumented treadmill at fixed self-selected speed, each test lasting 6 min. Leg-muscle fatigue (leg-muscle activation, measured with surface electromyography), cardiorespiratory fatigue (heart rate, rate of perceived exertion), gait and walking-adaptability performance were assessed. The study compared: (i) the first and last minute per test, (ii) normal and adaptive walking, and (iii) groups. Leg-muscle activation did not change during normal walking (p > 0.546), but declined over time during adaptive walking, especially in polio survivors (p < 0.030). Cardiorespiratory fatigue increased during all tests (p < 0.001), especially in polio survivors (p < 0.01), and was higher during adaptive than normal walking (p < 0.007). Target-stepping performance declined in both groups (p = 0.007), while narrow-beam walking improved in healthy individuals (p < 0.001) and declined in polio survivors (p < 0.001). Cardiorespiratory fatigue might further degrade walking adaptability, especially among polio survivors during narrow-beam walking. This might increase the risk of falls among polio survivors.

Effect of Natural Adenylcyclase/cAMP/CREB Signalling Activator Forskolin against Intra-Striatal 6-OHDA-Lesioned Parkinson's Rats: Preventing Mitochondrial, Motor and Histopathological Defects.

Parkinson's disease (PD) is characterised by dopaminergic neuronal loss in the brain area. PD is a complex disease that deteriorates patients' motor and non-motor functions. In experimental animals, the neurotoxin 6-OHDA induces neuropathological, behavioural, neurochemical and mitochondrial abnormalities and the formation of free radicals, which is related to Parkinson-like symptoms after inter-striatal 6-OHDA injection. Pathological manifestations of PD disrupt the cAMP/ATP-mediated activity of the transcription factor CREB, resulting in Parkinson's-like symptoms. Forskolin (FSK) is a direct AC/cAMP/CREB activator isolated from Coleus forskohlii with various neuroprotective properties. FSK has already been proven in our laboratory to directly activate the enzyme adenylcyclase (AC) and reverse the neurodegeneration associated with the progression of Autism, Multiple Sclerosis, ALS, and Huntington's disease. Several behavioural paradigms were used to confirm the post-lesion effects, including the rotarod, open field, grip strength, narrow beam walk (NBW) and Morris water maze (MWM) tasks. Our results were supported by examining brain cellular, molecular, mitochondrial and histopathological alterations. The FSK treatment (15, 30 and 45 mg/kg, orally) was found to be effective in restoring behavioural and neurochemical defects in a 6-OHDA-induced experimental rat model of PD. As a result, the current study successfully contributes to the investigation of FSK's neuroprotective role in PD prevention via the activation of the AC/cAMP/PKA-driven CREB pathway and the restoration of mitochondrial ETC-complex enzymes.

Filgrastim, a Recombinant Form of Granulocyte Colony-stimulating Factor, Ameliorates 3-nitropropionic Acid and Haloperidol-induced Striatal Neurotoxicity in Rats.

Striatal neurotoxicity is the pathological hallmark for a heterogeneous group of movement disorders like Tardive dyskinesia (TD) and Huntington's disease (HD). Both diseases are characterized by progressive impairment in motor function. TD and HD share common features at both cellular and subcellular levels. Filgrastim, a recombinant methionyl granulocyte colony-stimulating factor (GCSF), shows neuroprotective properties in in-vivo models of movement disorders. This study seeks to evaluate the neuroprotective effect of filgrastim in haloperidol and 3-NP-induced neurotoxicity in rats. The study was divided into two: in study one, rats were administered with haloperidol for 21days, filgrastim at the dose of (20, 40, 60µg/kg,s.c.) was administered once a day before haloperidol treatment and the following parameters (orofacial movements, rotarod, actophotometer) were performed to assess TD. Similarly, in the second study, rats were administered with 3-NP for 21days, filgrastim at a dose of (20 and 40µg/kg, s.c.) was administered, and the following parameters (rotarod, narrow beam walk, and open field test) were assessed for HD. On the 22nd day, animals were sacrificed and cortex and striatum isolated for oxidative stress (LPO, GSH, SOD, catalase, and nitrate) marker assessment. Results revealed that haloperidol and 3-NP treatment significantly impaired motor coordination, and oxidative defense inducing TD and HD-like symptoms. Treatment with filgrastim significantly averted haloperidol and 3-NP-induced behavioral and biochemical alterations. Conclusively, the neuroprotective effect of filgrastim is credited to its antioxidant properties. Hence, filgrastim might be a novel therapeutic candidate for the management of TD and HD.

Pharmacological Potential of the Standardized Methanolic Extract of Prunus armeniaca L. in the Haloperidol-Induced Parkinsonism Rat Model.

Parkinson's disease (PD) is a complex, age-related neurodegenerative disease that causes neuronal loss and dysfunction over time. An imbalance of redox potential of oxidative stress in the cell causes neurodegenerative diseases and dysfunction of neurons. Plants are a rich source of bioactive substances that attenuate oxidative stress in a variety of neurological disorders. The aim of the present study was to evaluate the Prunus armeniaca L. methanolic extract (PAME) for anti-Parkinson activity in rats. PD was induced with haloperidol (1 mg/kg, IP). The PAME was administered orally at 100, 300, and 800 mg/kg dose levels for 21 days. Behavioral studies (catalepsy test, hang test, open-field test, narrow beam walk, and hole-board test), oxidative stress biomarkers (SOD, CAT, GSH, and MDA) levels, neurotransmitters (dopamine, serotonin, and noradrenaline) levels, and acetylcholinesterase activity were quantified in the brain homogenate. Liver function tests (LFTs), renal function tests (RFTs), complete blood count (CBC), and lipid profiles were measured in the blood/serum samples to note the side effects of PAME at the selected doses. Histopathological analysis was performed on the brain (anti-PD study), liver, heart, and kidney (to check the toxicity of PAME on these vital organs). Motor functions were improved in the behavioral studies. Dopamine, serotonin, and noradrenaline levels were significantly increased (P < 0.001), whereas the level of acetylcholinesterase was decreased significantly (P < 0.001). The levels of superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) were increased, while malondialdehyde (MDA) and nitrite levels were decreased in the PAME-treated groups significantly compared with the disease control group, hence reducing oxidative stress. The incidence of toxicity was determined by biochemical analysis of LFT and RFT biomarkers testing. The histopathological analysis indicated that neurofibrillary tangles and plaques decreased in a dose-dependent manner in the PAME-treated groups. Based on the data, it is concluded that PAME possessed good anti-Parkinson activity, rationalizing the plant's traditional use as a neuroprotective agent.

Coronarin D attenuates MPTP-induced Parkinson’s disease in mice by inhibition of oxidative stress and apoptosis

Parkinson’s disease (PD) is a brain-related disease condition, globally it is the second most common neurodegenerative disease that mostly disturbs the brain motor control and action of the aged populations. It involves a tiny, dark portion of the brain denoted as substantia nigra. Dopamine is produced in the substantia nigra for the usage of the brain. This dopamine communicates messages among nerves and controls muscle movements. Coronarin D is a diterpenoid with exclusive pharmacological possessions and its effectiveness over a few neurogenerative diseases exposed to some intense properties. The present study was intended to exhibit the neuroprotective efficacy of Coronarin D over MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) induced animals. Oral management of Coronarin D (10 and 20 mg/kg body wt.) protects the MPTP-induced nigrostriatal dopamine (DA) depletion and its intermediate substances. Behavioral studies like narrow beam walk test, open field test and hang test were conducted to study the movement and actions of Coronarin D treated MPTP induced experimental animals, in which Coronarin D treated group III & IV animals showed better behavioral alterations. Our compound as well attenuated MPTP persuaded oxidative pressure in experimental animals. Apoptotic marker studies displayed that management with Coronarin D upturned MPTP induced programmed cell death, which might be its anti-apoptotic properties. Ultimately to conclude, Coronarin D recovered oxidative pressure, neurochemical alterations, apoptosis, and functional irregularities in investigational mice and propose a potential approach to disease management of neurodegenerative and its related disease.

Berberine Ameliorate Haloperidol and 3-Nitropropionic Acid-Induced Neurotoxicity in Rats.

Berberine due to its antioxidant properties, has been used around the globe significantly to treat several brain disorders. Also, oxidative stress is a pathological hallmark in neurodegenerative diseases like Huntington's disease (HD) and Tardive dyskinesia (TD). Berberine an alkaloid from plants has been reported to have neuroprotective potential in several animal models of neurodegenerative diseases. Hence, this study aims to evaluate the neuroprotective effect of berberine in the animal model of 3-nitropropionic acid (3-NP) induced HD and haloperidol induced tardive dyskinesia with special emphasis on its antioxidant property. The study protocol was divided into 2 phases, first phase involved the administration of 3-NP and berberine at the dose of (25, 50, and 100mg/kg) intraperitoneally (i.p) and orally (p.o.) respectively for 21days, and the following parameters (rotarod, narrow beam walk and photoactometer) as a measure of motor activity and striatal and cortical levels of (LPO, GSH, SOD, catalase, and nitrate) evaluated as a measure of oxidative stress were assessed for HD. Similarly in the second phase, TD was induced by using haloperidol, for 21days and berberine at the dose of (25, 50, and 100mg/kg) was administered, and both physical and biochemical parameters were assessed as mentioned for the HD study. The resultantdata indicated that berberine attenuate 3-NP and haloperidol-induced behavioral changes and improved the antioxidant capcity in rodents. Hence berberine might be a novel therapeutic candidate to manage TD & HD.

Oral magnesium sulphate administration in rats with minimal hepatic encephalopathy: NMR-based metabolic characterization of the brain

To investigate the metabolic changes in rats with minimal hepatic encephalopathy (MHE) treated with oral magnesium sulphate administration. A total of 30 Sprague-Dawley rats were divided into a control group and MHE group (further divided into an MHE group and an MHE-Mg group treated with oral administration of 124 mg/kg/day magnesium sulphate). Morris water maze (MWM), Y maze and narrow beam walking (NBW) were used to evaluate cognitive and motor functions. Brain manganese and magnesium content were measured. The metabolic changes in rats with MHE were investigated using hydrogen-nuclear magnetic resonance. Metabolomic signatures were identified with enrichment and pathway analysis. A significantly decreased number of entries into the MWM within the range of interest, longer latency and total time during NBW, and higher brain manganese content were found in rats with MHE. After magnesium sulphate treatment, the rats with MHE had better behavioural performance and lower brain manganese content. The 25 and 26 metabolomic signatures were identified in the cortex and striatum of rats with MHE. The pathway analysis revealed alanine, aspartate and glutamate metabolism as the major abnormal metabolic pathways associated with these metabolomic signatures. Alanine, aspartate and glutamate metabolism are major abnormal metabolic pathways in rats with MHE, which could be restored by magnesium sulphate treatment.

Neuroprotective effect of silymarin against 3‐nitropropionic acid‐induced Huntington’s like symptoms in rats

AbstractBackgroundNeuroprotective effect of silymarin against 3‐nitropropionic acid‐induced Huntington’s like symptoms in rats.MethodHuntington's disease (HD) is a chronic neurodegenerative and hyperkinetic movement disorder characterized by degeneration of GABAergic medium spiny neurons, mainly affecting striatum and cortex. 3‐nitropropionic acid (3‐NP) acts as a suitable animal model to induce HD like symptoms in rats. Therefore, the present study aimed to investigate the neuroprotective effect of silymarin against 3‐NP induced HD like symptoms in rats. Rats were administered 3‐NP (10 mg/kg; i.p) for 21 days, whereas silymarin (50, 100 and 200 mg/kg; p.o) was given once a day, 1 hour before the 3‐NP treatment for 21 days. Body weight and behavioral parameters (rotarod, open field test, and narrow beam walk activities) were assessed on 1st, 7th, 14th, and 21st days. On the 22nd day, the animals were sacrificed, and the rat striatum and cortex were isolated to perform biochemical parameters (lipid peroxidation; glutathione; superoxide dismutase; nitrite and catalase).ResultSystemic 3‐NP treatment significantly reduced body weight, motor‐coordination, and oxidative defense. Pretreatment with silymarin significantly attenuated the 3‐NP induced alterations in body weight, locomotor activities, and oxidative defense.ConclusionOur results revealed that in a 3‐NP model of HD, silymarin could underlie the possible neuroprotective effect, which may provide insight into the therapeutic potential of silymarin for HD.

Impaired mitochondrial functions and energy metabolism in MPTP-induced Parkinson's disease: comparison of mice strains and dose regimens.

Heterogenous diseases such as Parkinson's disease (PD) needs an efficient animal model to enhance understanding of the underlying mechanisms and to develop therapeutics. MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine), a neurotoxin, has been widely used to replicate the pathophysiology of PD in rodents, however, the knowledge about its effects on energy metabolism is limited. Moreover, susceptibility to different dose regimens of MPTP also varies among mice strains. Thus, the present study compares the effect of acute and sub-acute MPTP administration on mitochondrial functions in C57BL/6 and BALB/c mice. In addition, activity of enzymes involved in energy metabolism was also studied along with behavioural alterations. The findings show that acute dose of MPTP in C57BL/6 mice had more profound effect on the activity of electron transport chain complexes. Further, the activity of MAO-B was increased following acute and sub-acute MPTP administration in C57BL/6 mice. However, no significant change was observed in BALB/c mice. Acute MPTP treatment resulted in decreased mitochondrial membrane potential along with increasedswelling of mitochondria in C57BL/6 mice. In addition, perturbations were observed in hexokinase, the rate limiting enzyme of glycolysis and pyruvate dehydrogenase, the enzymes that connects glycolysis and TCA cycle. The activity of TCA cycle enzymes; citrate synthase, aconitase, isocitrate dehydrogenase and fumarase were also altered following MPTP intoxication. Furthermore, acute MPTP administration led to drastic reduction in dopamine levels in striatum of C57BL/6 as compared to BALB/c mice. Behavioral tests such as open field, narrow beam walk and footprint analysis revealed severe impairment in locomotor activity in C57BL/6 mice. These results clearly demonstrate that C57BL/6 strain is more vulnerable to MPTP-induced mitochondrial dysfunctions, perturbations in energy metabolism and motor defects as compared to BALB/c strain. Thus, the findings suggest that the dose and strain of mice need to be considered for pre-clinical studies using MPTP-induced model of Parkinson's disease.

L-Theanine ameliorates motor deficit, mitochondrial dysfunction, and neurodegeneration against chronic tramadol induced rats model of Parkinson’s disease

Parkinson’s disease (PD) is the second most prevalent progressive neurodegenerative disease, characterized by loss of dopaminergic neurons in substantia nigra, with deficiency of dopamine in the striatum. Tramadol is safe analgesic but long-term use confirmed to elevate oxidative stress, neuroinflammation, mitochondrial dysfunction, in brain leads to motor deficits. l-Theanine is an active constituent of green tea which prevents neuronal loss, mitochondrial failure and improves dopamine, gamma-aminobutyric acid (GABA), serotonin levels and in the central nervous system (CNS) via antioxidant, anti-inflammatory, and neuromodulatory properties. In the present study, tramadol was injected intraperitoneally to Wister rats for 28 days at a dose of 50 mg/kg. l-Theanine (25, 50, and 100 mg/kg) was administered orally 3 h before tramadol administration from day 14 to day 28. Behavioral analyses including rotarod, narrow beam walk, open field, and grip strength were used to evaluate motor coordination on a weekly basis. On the day 29, all Wistar rats were sacrificed and striatum homogenates were used for biochemical (lipid peroxidation, nitrite, glutathione, glutathione peroxidase activity, superoxide dismutase, catalase, mitochondrial complex I, IV, and cyclic adenosine monophosphate), neuroinflammatory markers (tumor necrosis factor-α, interleukin-1β, and interleukin-17), and neurotransmitters (dopamine, norepinephrine, serotonin, GABA, and glutamate) analysis. Chronic tramadol treatment caused motor deficits reduced antioxidant enzymes level, increased striatal proinflammatory cytokines release, dysbalanced neurotransmitters, and reduced mitochondrial complex activity I, IV, and cAMP activity. However, l-theanine administration attenuated behavioral, biochemical, neuroinflammatory, neurotransmitters, and mitochondrial activity indicated it as a promising neuroprotective potential against degenerative changes in experimental model of PD.

Neuroprotective Effects of Trehalose and Sodium Butyrate on Preformed Fibrillar Form of α-Synuclein-Induced Rat Model of Parkinson's Disease.

Therapeutic options for Parkinson's disease (PD) are limited to a symptomatic approach, making it a global threat. Targeting aggregated alpha-synuclein (α-syn) clearance is a gold standard for ameliorating PD pathology, bringing autophagy into the limelight. Expression of autophagy related genes are under the regulation by histone modifications, however, its relevance in PD is yet to be established. Here, preformed fibrillar form (PFF) of α-syn was used to induce PD in wistar rats, which were thereafter subjected to treatment with trehalose (tre, 4g/kg, orally), a potent autophagy inducer and sodium butyrate (SB, 300 mg/kg, orally), a pan histone deacetylase inhibitor alone as well as in combination. The combination treatment significantly reduced motor deficits as evidenced after rotarod, narrow beam walk, and open field tests. Novel object location and recognition tests were performed to govern cognitive abnormality associated with advanced stage PD, which was overcome by the combination treatment. Additionally, with the combination, the level of pro-inflammatory cytokines were significantly reduced, along with elevated levels of dopamine and histone H3 acetylation. Further, mRNA analysis revealed that levels of certain autophagy related genes and proteins implicated in PD pathogenesis significantly improved after administration of both tre and SB. Immunofluorescence and H&E staining in the substantia nigra region mirrored a potential improvement after treatment with both tre and SB. Therefore, outcomes of the present study were adequate to prove that combinatorial efficacy with tre and SB may prove to be a formidable insight into ameliorating PD exacerbated by PFF α-syn as compared to its individual efficacy.

Hydroxytyrosol as anti-parkinsonian molecule: Assessment using in-silico and MPTP-induced Parkinson’s disease model

3-Hydroxytyrosol (HXT) is a natural polyphenol present in extra virgin olive oil. It is a key component of Mediterranean diet and is known for its strong antioxidant activity. The present study evaluated the potential of HXT as an anti-parkinsonian molecule in terms of its ability to inhibit MAO-B and thereby maintaining dopamine (DA) levels in Parkinson’s disease (PD). In-silico molecular docking study followed by MMGBSA binding free energy calculation revealed that HXT has a strong binding affinity for MAO-B in comparison to MAO-A. Moreover, rasagiline and HXT interacted with the similar binding sites and modes of interactions. Additionally, molecular dynamics simulation studies revealed stable nature of HXT-MAO-B interaction and also provided information about the amino acid residues involved in binding. Moreover, in vitro studies revealed that HXT inhibited MAO-B in human platelets with IC50 value of 7.78 μM. In vivo studies using MPTP-induced mouse model of PD revealed increase in DA levels with concomitant decrease in DA metabolites (DOPAC and HVA) on HXT treatment. Furthermore, MAO-B activity was also inhibited on HXT administration to PD mice. In addition, HXT treatment prevented MPTP-induced loss of DA neurons in substantia nigra and their nerve terminals in the striatum. HXT also attenuated motor impairments in PD mice assessed by catalepsy bar, narrow beam walk and open field tests. Thus, the present findings reveal HXT as a potential inhibitor of MAO-B, which may be used as a lead molecule for the development of therapeutics for PD.

Neuroprotective effects of roflumilast against quinolinic acid-induced rat model of Huntington's disease through inhibition of NF-κB mediated neuroinflammatory markers and activation of cAMP/CREB/BDNF signaling pathway.

Huntington's disease (HD) is a progressive neurodegenerative and hyperkinetic movement disorder. Decreased activity of cAMP-responsive element-binding protein (CREB) is thought to contribute to the death of striatal medium spiny neurons in HD. The present study has been designed to explore the possible role of roflumilast against qunilonic acid (QA) induced neurotoxicity in rats intending to investigate whether it inhibits the neuroinflammatory response through activation of the cAMP/CREB/BDNF signaling pathway. QA was microinjected (200nmol/2µl, bilaterally) through the intrastriatal route in the stereotaxic apparatus. Roflumilast (0.5, 1, and 2mg/kg, orally) once-daily treatment for 21days significantly improved locomotor activity in actophotometer, motor coordination in rotarod, and impaired gait performance in narrow beam walk test. Moreover, roflumilast treatment significantly attenuated oxidative and nitrosative stress (p<0.05) through attenuating lipid peroxidation nitrite concentration and enhancing reduced glutathione, superoxide dismutase, and catalase levels. Furthermore, roflumilast also significantly decreased elevated pro-inflammatory cytokines like TNF-α (p<0.01), IL-6 (p<0.01), IFN-γ (p<0.05), NF-κB (p<0.05) and significantly increased BDNF(p<0.05) in the striatum and cortex of rat brain. The results further demonstrated that roflumilast effectively increased the gene expression of cAMP(p<0.05), CREB(p<0.05) and decreased the gene expression of PDE4 (p<0.05) in qRT-PCR. These results conclusively depicted that roflumilast could be a potential candidate as an effective therapeutic agent in the management of HD through the cAMP/CREB/BDNF signaling pathway.