Effect ofWithania somnifera root extract on haloperidol-induced catalepsy in albino mice

Icariin attenuates dopaminergic neural loss in haloperidol-induced Parkinsonism in rats via GSK-3β and tyrosine hydroxylase regulation mechanism

Parkinson's Disease (PD) is an age-dependent, incessant, dynamic neurodegenerative illness. In animal models, the administration of the dopaminergic D2 antagonist Haloperidol (HP) affects the nigrostriatal pathway, inducing catalepsy, a state of immobility like PD, bradykinesia, and akinesia. The present study investigated the neural effects of Icariin (ICA), a flavonoid derived from Herba Epimedii, against HP-induced PD in rats compared to a standard drug levodopa (L-DOPA). Twenty-four adult male rats were divided into 4 groups: the control group treated with vehicle, the 2nd group treated with HP intraperitoneally, the 3rd group treated with the same dose of HP+L-DOPA orally, and the 4th one, treated with the same dose of HP+ICA orally. All the groups were treated for fourteen consecutive days. Two days before the last dose, locomotor activity was assessed in open field and rotarod tasks. At the end of the experiment, the malondialdehyde, nitric oxide (NO), iron, glycogen synthase kinase-3beta (GSK-3β), and tyrosine hydroxylase (TH) contents, glutathione S-transferase, catalase, superoxide dismutase, activities were estimated in the midbrain. Also, cortex and midbrain monoamine contents (norepinephrine, dopamine, and serotonin) were determined. Moreover, the midbrain histopathology was detected in all treated groups. The results suggested that the neuroleptic effect of HP was completely improved by ICA. This improvement occurred by decreasing the neurotoxicity via lowering midbrain lipid peroxidation, NO, GSK-3β contents, increasing antioxidant biomarkers, TH, and recovering the treated groups' cortex and midbrain monoamines contents. In conclusion, this study suggests that ICA is a suitable treatment for Parkinson's induced by HP.

Neuropharmacological studies of ethanolic extract of Vaccinium corymbosum on Alzheimer’s type dementia and catatonia in Swiss albino mice

Introduction: Neuroactive herbal drugs enriched with antioxidants are valuable in treating neurocognitive dysfunction and Vaccinium corymbosum, enriched with antioxidant phytochemicals, is used for treating memory disorders. Hence, the present study evaluated the neuroprotective effects of ethanolic extract of Vaccinium corymbosum (EEVC) on aluminium chloride(AlCl3)-induced Alzheimer’s type of dementia and haloperidol-induced catalepsy-associated behavioural changes. Methods:In vitro antioxidant potential was evaluated using 1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The total phenolic content (TPC) was quantified. For in vivo studies, AlCl3 (100 mg/kg) was orally administered for 42 days, whereas the EEVC was administered on the 21st day until the 42nd day in two doses (200 mg/kg and 400 mg/kg). In the haloperidol-induced group, EEVC was treated for 21 days, and haloperidol (1 mg/kg) was administered to induce behavioural changes. Open-field, Y-Maze and traction tests were performed, and the mice brain acetylcholinesterase (AChE) enzyme was determined. Results: IC50 values in DPPH and ABTS assays were 85.5 μg/mL and 80 μg/mL, respectively and the total phenolic content of EEVC was found to be 0.166 mg. In a behavioral study, animals treated with 200 mg/kg and 400 mg/kg of EEVC exhibited a neuroprotective impact on AlCl3-induced neurodegeneration and haloperidol-induced behavioral changes with significant inhibition (P < 0.05 and P < 0.01, respectively) in acetylcholinesterase enzyme. Conclusion: The neuroprotection by EEVC postulated that it is a promising therapeutic agent for treating behavioral and cognitive dysfunctions. Further investigations on pro-inflammatory cytokine and neuroendocrine regulation in transgenic Alzheimer’s disease (AD)models complement the therapeutic value of V. corymbosum.

Plant-Derived Natural Products for Parkinson's Disease Therapy

Plant-derived natural products have made their own niche in the treatment of neurological diseases since time immemorial. Parkinson's disease (PD), the second most prevalent neurodegenerative disorder, has no cure and the treatment available currently is symptomatic. This chapter thoughtfully and objectively assesses the scientific basis that supports the increasing use of these plant-derived natural products for the treatment of this chronic and progressive disorder. Proper considerations are made on the chemical nature, sources, preclinical tests and their validity, and mechanisms of behavioural or biochemical recovery observed following treatment with various plants derived natural products relevant to PD therapy. The scientific basis underlying the neuroprotective effect of 6 Ayurvedic herbs/formulations, 12 Chinese medicinal herbs/formulations, 33 other plants, and 5 plant-derived molecules have been judiciously examined emphasizing behavioral, cellular, or biochemical aspects of neuroprotection observed in the cellular or animal models of the disease. The molecular mechanisms triggered by these natural products to promote cell survivability and to reduce the risk of cellular degeneration have also been brought to light in this study. The study helped to reveal certain limitations in the scenario: lack of preclinical studies in all cases barring two; heavy dependence on in vitro test systems; singular animal or cellular model to establish any therapeutic potential of drugs. This strongly warrants further studies so as to reproduce and confirm these reported effects. However, the current literature offers scientific credence to traditionally used plant-derived natural products for the treatment of PD.

W ithania somnifera (Ashwagandha) in neurobehavioural disorders induced by brain oxidative stress in rodents: a systematic review and meta-analysis

Objectives

W ithania somnifera has been in use for several thousand years in Ayurveda to treat various neurological disorders. There is, however, not much scientific data on its protective role in neuronal pathology specifically against brain oxidative stress. Hence, an attempt is made in this work for systematic review and meta-analysis of W. somnifera on neurobehavioural disorders induced by brain oxidative stress in rodents.

Methods

A systematic search of the effect of W. somnifera on brain oxidative stress-induced neuronal pathology was performed using electronic databases. The systematic review was performed on neurobehavioural parameters, whereas meta-analysis of W. somnifera effect was done on oxidative stress markers (superoxide dismutase, catalase, glutathione peroxidase, glutathione and lipid peroxidation), nitrite, protein carbonyl, AchE, ChAT and Ach of rodent brain. Data were analysed using Review Manager Software.

Key findings

Twenty-eight studies were selected based upon the inclusion and exclusion criteria. W. somnifera appreciably inhibited the neurological abnormalities due to oxidative stress in rodent brain produced by different physical and chemical stimuli. W. somnifera also significantly restored the altered oxidative and other stress markers in different parts of rodent brain.

Summary

The systematic review provides scientific evidence for the traditional claim of W. somnifera use in different neurological aliments. However, future clinical trials are mandated to establish the therapeutic efficacy and safety in human beings.

Novel action of metformin in the prevention of haloperidol-induced catalepsy in mice: Potential in the treatment of Parkinson's disease?

Metformin is widely used to treat type II diabetes and other metabolic syndromes. In addition, it has been shown to increase neurogenesis, spatial memory formation and reduce the risk of Parkinson's disease. On this basis, the aim of the present study was the investigation of the protective potential of metformin in the haloperidol-induced catalepsy model of Parkinson's disease in mice. The effect of metformin (20 - 100mg/kg, p.o) on motor coordination was assessed using rotarod and forced swimming tests (FST), while the effect on memory function was evaluated using the Y-maze test. The neuroprotective activity was investigated in acute/chronic (21days) haloperidol-induced catalepsy in mice. On the 21st day, biochemical estimation of nitrosative and oxidative stress parameters was carried out. Metformin (50 or 100mg/kg, p.o.) did not affect motor coordination in rotarod test and FST but significantly reversed haloperidol-induced memory deficit (+35.50%) at 100mg/kg. Importantly, metformin significantly reduced the duration of catalepsy score during acute and chronic catalepsy tests as compared to trihexylphenidyl (reference standard). Intraperitoneal chronic injection of haloperidol (1mg/kg) significantly increased malondialdehyde and nitrite levels, while it significantly attenuated the activity of reduced glutathione, catalase and superoxide dismutase. Moreover, oral chronic administration of metformin significantly attenuated the haloperidol-induced increase of malondialdehyde and nitrite, as well as the deficit of glutathione and catalase. These findings suggest that metformin protects against haloperidol-induced catalepsy through inhibition of oxidative/nitrosative stress and has the potential for adjuvant action in the management of Parkinson's disease.

Caffeine withdrawal retains anticataleptic activity but Withania somnifera withdrawal potentiates haloperidol-induced catalepsy in mice

The previous study showed that chronic treatment with Withania somnifera extract (WS) inhibited haloperidol-induced catalepsy. It is suggested that caffeine and WS may be useful adjuvants in pharmacotherapy of Parkinson's disease. There are no studies on the effect of haloperidol on mice withdrawn from caffeine or W. somnifera. We therefore studied the effect of a single administration of standardised WS containing 5.1% total withanolides (WS, 30 or 100 mg kg(-1) i.p.) and/or caffeine (3 mg kg(-1) i.p.) and withdrawal from 6 days treatment with WS and/or caffeine, on haloperidol-induced catalepsy in albino mice. Single administration of both WS and caffeine, used either alone or in combination, significantly inhibited catalepsy. Mice withdrawn from caffeine significantly inhibited haloperidol-induced catalepsy, but mice withdrawn from WS showed increased catalepsy. The study indicated that withdrawal from WS does not retain anticataleptic activity, and caffeine but not WS may be a good adjuvant in pharmacotherapy of Parkinson's disease.