Protective effect of Convolvulus pluricaulis standardized extract and its fractions against 3-nitropropionic acid-induced neurotoxicity in rats

A clinical study and future prospects for bioactive compounds and semi-synthetic molecules in the therapies for Huntington's disease

A neurodegenerative disorder (ND) refers to Huntington's disease (HD) which affects memory loss, weight loss, and movement dysfunctions such as chorea and dystonia. In the striatum and brain, HD most typically impacts medium-spiny neurons. Molecular genetics, excitotoxicity, oxidative stress (OS), mitochondrial, and metabolic dysfunction are a few of the theories advanced to explicit the pathophysiology of neuronal damage and cell death. Numerous in-depth studies of the literature have supported the therapeutic advantages of natural products in HD experimental models and other treatment approaches. This article briefly discusses the neuroprotective impacts of natural compounds against HD models. The ability of the discovered natural compounds to suppress HD was tested using either in vitro or in vivo models. Many bioactive compounds considerably lessened the memory loss and motor coordination brought on by 3-nitropropionic acid (3-NP). Reduced lipid peroxidation, increased endogenous enzymatic antioxidants, reduced acetylcholinesterase activity, and enhanced mitochondrial energy generation have profoundly decreased the biochemical change. It is significant since histology showed that therapy with particular natural compounds lessened damage to the striatum caused by 3-NP. Moreover, natural products displayed varying degrees of neuroprotection in preclinical HD studies because of their antioxidant and anti-inflammatory properties, maintenance of mitochondrial function, activation of autophagy, and inhibition of apoptosis. This study highlighted about the importance of bioactive compounds and their semi-synthetic molecules in the treatment and prevention of HD.

Phytotherapeutic alternatives for neurodegenerative dementias: Scientific review, discussion and therapeutic proposal

The incidence and prevalence of age-related neurodegenerative dementias have been increasing. There is no curative therapy and conventional drug treatment can cause problems for patients. Medicinal plants traditionally used for problems associated with ageing are emerging as a therapeutic resource. The main aim is to give a proposal for use and future research based on scientific knowledge and tradition. A literature search was conducted in several searchable databases. The keywords used were related to neurodegenerative dementias, ageing and medicinal plants. Boolean operators and filters were used to focus the search. As a result, there is current clinical and preclinical scientific information on 49 species used in traditional medicine for ageing-related problems, including neurodegenerative dementias. There are preclinical and clinical scientific evidences on their properties against protein aggregates in the central nervous system and their effects on neuroinflammation, apoptosis dysregulation, mitochondrial dysfunction, gabaergic, glutamatergic and dopaminergic systems alterations, monoamine oxidase alterations, serotonin depletion and oestrogenic protection. In conclusion, the potential therapeutic effect of the different medicinal plants depends on the type of neurodegenerative dementia and its stage of development, but more clinical and preclinical research is needed to find better, safer and more effective treatments.

The Emerging Landscape of Natural Small-molecule Therapeutics for Huntington's Disease

Huntington's disease (HD) is a rare and fatal neurodegenerative disorder with no diseasemodifying therapeutics. HD is characterized by extensive neuronal loss and is caused by the inherited expansion of the huntingtin (HTT) gene that encodes a toxic mutant HTT (mHTT) protein having expanded polyglutamine (polyQ) residues. Current HD therapeutics only offer symptomatic relief. In fact, Food and Drug Administration (FDA) approved two synthetic small-molecule VMAT2 inhibitors, tetrabenazine (1) and deutetrabenazine (2), for managing HD chorea and various other diseases in clinical trials. Therefore, the landscape of drug discovery programs for HD is evolving to discover disease- modifying HD therapeutics. Likewise, numerous natural products are being evaluated at different stages of clinical development and have shown the potential to ameliorate HD pathology. The inherent anti-inflammatory and antioxidant properties of natural products mitigate the mHTT-induced oxidative stress and neuroinflammation, improve mitochondrial functions, and augment the anti-apoptotic and pro-autophagic mechanisms for increased survival of neurons in HD. In this review, we have discussed HD pathogenesis and summarized the anti-HD clinical and pre-clinical natural products, focusing on their therapeutic effects and neuroprotective mechanism/s.

Role of Shankhpushpi (Convolvulus pluricaulis) in Neurological Disorders: An Umbrella Review Covering Evidence from Ethnopharmacology to Clinical Studies

C. pluricaulis Choisy (C. pluricaulis), a perennial herb aka C. microphyllus Sieb. and C. Prostratus Forsk. is being used as a traditional folk medicine for a variety of ailments. In this article, we collected information about C. pluricaulis through electronic search using PubMed, SciFinder, Google Scholar, and Web of Science as well as network pharmacology is done. This comprehensive review sheds light on the plant profile, phytochemistry, neuropharmacological, and toxicological data of C. pluricaulis. The crude herb and its metabolites have exhibited a wide range of in vitro and in vivo neuropharmacological effects, including memory enhancement, anxiolytic, tranquilizing, anti-depressant, anti-stress, neurodegenerative, anti-inflammatory, anti-oxidant, analgesic, sedative, anti-convulsant, and Alzheimer's disease-reversing effects. Network pharmacology results indicate that compounds from C. pluricaulis interact with various proteins, neuro synapses, signaling pathways, and serotonergic synapse which plays a crucial role in neurotransmission, Alzheimer's disease, long-term depression, addictions to alcohol, cognitive disorders, psychological conditions, and increasing serotonin concentration in synapses.

Medha Plus - A novel polyherbal formulation ameliorates cognitive behaviors and disease pathology in models of Alzheimer's disease

Alzheimer's disease (AD) is a multi-faceted neurodegenerative disorder that leads to drastic cognitive impairments culminating in death. Pathologically, it is characterized by amyloid-β (Aβ) plaques, neurofibrillary tangles and neurodegeneration in brain. Complete cure of AD remains elusive to date. Available synthetic drugs only provide symptomatic reliefs targeting single molecule, hence, are unable to address the multi-factorial aspects in AD pathogenesis. It is imperative to develop combinatorial drugs that address the multiple molecular targets in AD. We show a unique polyherbal formulation of Brahmi, Mandukaparni, Shankhpushpi, Yastimadhu, Kokilaksha and Shunthi called 'Medha Plus' (MP), conventionally used for improving memory and reducing anxiety, was able to ameliorate cognitive deficits and associated pathological hallmarks of AD. Viability assays revealed that MP prevented Aβ-induced loss of neurites as well as neuronal apoptosis in cellular models. An array of behavioral studies showed that MP was able to recover AD-associated memory deficits in both Aβ-injected rats and 5XFAD mice. Immunohistochemical studies further revealed that MP treatment reduced Aβ depositshpi and decreased apoptotic cell death in the hippocampus. Enzymatic assays demonstrated anti-oxidative and anti-acetyl cholinesterase properties of MP especially in hippocampus of Aβ-injected rats. An underlying improvement in synaptic plasticity was observed with MP treatment in 5XFAD mice along with an increased expression of phospho-Akt at serine 473 indicating a role of PI3K/Akt signaling in correcting these synaptic deficits. Thus, our strong experiment-driven approach shows that MP is an incredible combinatorial drug that targets multiple molecular targets with exemplary neuroprotective properties and is proposed for clinical trial.

Recombinant human erythropoietin and interferon-β-1b protect against 3-nitropropionic acid-induced neurotoxicity in rats: possible role of JAK/STAT signaling pathway

3-Nitropropionic acid (3-NP) model serves as a beneficial tool to evaluate the effect of novel treatments for Huntington’s disease (HD). The aim of the present study was to demonstrate the neuroprotective effect of recombinant human erythropoietin (rhEPO) and interferon-beta-1b (IFN-β-1b) in 3-NP-induced neurotoxicity in rats. Rats were injected with 3-NP (10 mg/kg/day, i.p) for 2 weeks and were divided into five subgroups; the first served as the HD group, the second received rhEPO (5000 IU/kg/every other day, i.p.) for 2 weeks, the third received rhEPO starting from the 5th day of 3-NP injection, the fourth received IFN-β-1b (300,000 units, every day other day, s.c) for 2 weeks, and the last received IFN-β-1b starting from the 5th day of 3-NP injection. All treatments significantly improved motor and behavior performance of rats. Moreover, all treatments markedly restored mitochondrial function as well as brain-derived neurotrophic factor level, and reduced oxidative stress biomarkers, pro-inflammatory mediators, nuclear factor kappa B expression, caspase-3, and Bax/Bcl2 ratio in the striatum. In conclusion, the present study demonstrates the neuroprotective potential of rhEPO or IFN-β-1b on 3-NP-induced neurotoxicity in rats. Furthermore, our study suggests that activation of JAK2/STAT3 or JAK1/STAT3 may contribute to the neuroprotective activity of rhEPO or IFN-β-1b, respectively. We also found that early treatment with rhEPO did not confer any benefits compared with late rhEPO treatment, while early IFN-β-1b showed a marked significant benefit compared with late IFN-β-1b.

Protective Effect of Natural Products against Huntington's Disease: An Overview of Scientific Evidence and Understanding Their Mechanism of Action

Huntington's disease (HD), a neurodegenerative disease, normally starts in the prime of adult life, followed by a gradual occurrence of characteristic psychiatric disturbances and cognitive and motor dysfunction. To the best of our knowledge, there is no treatment available to completely mitigate the progression of HD. Among various therapeutic approaches, exhaustive literature reports have confirmed the medicinal benefits of natural products in HD experimental models. Building on this information, this review presents a brief overview of the neuroprotective mechanism(s) of natural products against in vitro/in vivo models of HD. Relevant studies were identified from several scientific databases, including PubMed, ScienceDirect, Scopus, and Google Scholar. After screening through literature from 2005 to the present, a total of 14 medicinal plant species and 30 naturally isolated compounds investigated against HD based on either in vitro or in vivo models were included in the present review. Behavioral outcomes in the HD in vivo model showed that natural compounds significantly attenuated 3-nitropropionic acid (3-NP) induced memory loss and motor incoordination. The biochemical alteration has been markedly alleviated with reduced lipid peroxidation, increased endogenous enzymatic antioxidants, reduced acetylcholinesterase activity, and increased mitochondrial energy production. Interestingly, following treatment with certain natural products, 3-NP-induced damage in the striatum was ameliorated, as seen histologically. Overall, natural products afforded varying degrees of neuroprotection in preclinical studies of HD via antioxidant and anti-inflammatory properties, preservation of mitochondrial function, inhibition of apoptosis, and induction of autophagy.

Use of medicinal plants for headache, and their potential implication in medication-overuse headache: Evidence from a population-based study in Nepal

Background

In Nepal, traditional treatment using medicinal plants is popular. Whereas medication-overuse headache is, by definition, caused by excessive use of acute headache medication, we hypothesized that medicinal plants, being pharmacologically active, were as likely a cause.

Methods

We used data from a cross-sectional, nationwide population-based study, which enquired into headache and use of medicinal plants and allopathic medications. We searched the literature for pharmacodynamic actions of the medicinal plants.

Results

Of 2100 participants, 1794 (85.4%) reported headache in the preceding year; 161 (7.7%) reported headache on ≥15 days/month, of whom 28 (17.4%) had used medicinal plants and 117 (72.7%) allopathic medication(s). Of 46 with probable medication-overuse headache, 87.0% (40/46) were using allopathic medication(s) and 13.0% (6/46) medicinal plants, a ratio of 6.7:1, higher than the overall ratio among those with headache of 4.9:1 (912/185). Of 60 plant species identified, 49 were pharmacodynamically active on the central nervous system, with various effects of likely relevance in medication-overuse headache causation.

Conclusions

MPs are potentially a cause of medication-overuse headache, and not to be seen as innocent in this regard. Numbers presumptively affected in Nepal are low but not negligible. This pioneering project provides a starting point for further research to provide needed guidance on use of medicinal plants for headache.

Development and Validation of a Novel, Rapid Gradient HPLC Method for Simultaneous Estimation of Bioactive Marker Compounds in a Mixture of Convolvulus pluricaulis, Withania somnifera and Bacopa monnieri Extracts

The use of herbs as medicine is an ancient form of healthcare known to mankind. Standardization of herbal medicines is however a challenging task and is the major bottleneck in their acceptance as the primary therapeutic option. The aim of this study was to develop and validate a simple, rapid HPLC method for standardizing the mixture of extracts of three Medhya Rasayanas (neurotonic), Convolvulus pluricaulis, Withania somnifera and Bacopa monnieri. Simultaneous estimation of the respective bioactive markers of these plants viz., scopoletin, withaferin A, bacoside A 3, bacopaside II, jujubogenin and bacosaponin C has been reported for the first time. The method was developed using Waters Hybrid X-Bridge shield with BEH technology 2.5 μm, 4.6 × 75 mm column and validated according to ICH guidelines. The 20 minutes run time makes the method eco-friendly. The method was linear over a range of 12.5-400 ng/10 μL for scopoletin and 62.5-2,000 ng/10 μL for withaferin A, bacoside A 3, bacopaside II, jujubogenin and bacosaponin C with detection limits of 8.0, 48.3, 30.4, 40.7, 15.6 and 18.9 ng/10 μL and quantification limits of 24.5, 146.5, 92.2, 123.4, 47.4 and 57.4 ng/10 μL, respectively. The correlation coefficient for each analyte was >0.999. The intra-day and inter-day precision was <2%. These results confirmed the precision, accuracy and robustness of the proposed method.

Standardized extract of Lactuca sativa Linn. and its fractions abrogates scopolamine-induced amnesia in mice: A possible cholinergic and antioxidant mechanism

OBJECTIVES

The present study was designed to evaluate the efficacy of Lactuca sativa (LS) Linn. (Asteraceae) against scopolamine-induced amnesia and to validate its traditional claim as memory enhancer.

METHODS

Ethanol extract of fresh LS leaves (LSEE), standardized on the basis of quercetin content, was successively partitioned using various solvents viz., hexane, ethyl acetate, and n-butanol in increasing order of polarity. LSEE (50, 100, and 200 mg/kg) and its various fractions (at a dose equivalent to dose of LSEE exhibiting maximum activity), administered orally for 14 days, were evaluated for their memory enhancing effect against scopolamine-induced (1 mg/kg, i.p.) amnesia in 3-4 months old male Laca mice (n = 6 in each group). The memory enhancing effect was evaluated using behavioural (elevated plus maze, novel object recognition and Morris water maze tests) and biochemical parameters (acetylcholinesterase activity, malonaldehyde, superoxide dismutase, nitrite, catalase, and reduced gultathione content). The results of the test substances were compared with both scopolamine and donepezil that was used as a standard memory enhancer and acetylcholinesterase inhibitor.

RESULTS

Scopolamine elicit marked deterioration of memory and alteration in biochemical parameters in comparison to the control group. LSEE and its n-butanol and aqueous fractions significantly (P < 0.05) attenuated the scopolamine-induced amnesia that was evident in all the behavioural and biochemical test parameters. LSEE (200 mg/kg) and n-butanol fraction (15 mg/kg) exhibited maximum anti-amnesic effect among various tested dose levels.

DISCUSSION

The results exhibited that LS prophylaxis attenuated scopolamine-induced memory impairment through its acetylcholinesterase inhibitory and antioxidant activity validating its traditional claim.

Ameliorating effect of Celastrus paniculatus standardized extract and its fractions on 3-nitropropionic acid induced neuronal damage in rats: possible antioxidant mechanism

CONTEXT

Celastrus paniculatus Wild. (Celasteraceae) (CP) is a well-known Ayurvedic 'Medhya Rasayana' (nervine tonic), used extensively as a neuro-protective and memory enhancer, and in different central nervous system disorders.

OBJECTIVE

To evaluate the effect of CP against 3-nitropropionic acid (3-NP) induced Huntington's disease (HD) like symptoms in Wistar male rats.

MATERIALS AND METHODS

The ethanol extract of CP seeds (CPEE), prepared by maceration, was standardized on the basis of linoleic acid content (6.42%) using thin layer chromatography densitometric analysis. Protective effect of CPEE (100 and 200 mg/kg) and its various fractions, viz., petroleum ether (40 mg/kg), ethyl acetate (2.5 mg/kg), n-butanol (7 mg/kg) and aqueous (18 mg/kg), administered orally for 20 days, against 3-NP (10 mg/kg, i.p. for 14 days) was assessed by their effect on body weight, locomotor activity, grip strength, gait pattern and cognitive dysfunction and biochemical parameters for oxidative damage in the striatum and cortex regions of the brain.

RESULTS

CPEE (100 and 200 mg/kg) treated animals exhibited a significant (p < 0.05) improvement in behavioural and oxidative stress parameters in comparison to only 3-NP treated animals. Amongst various tested fractions of CPEE, aqueous fraction (AF) at 18 mg/kg exhibited maximum reversal of 3-NP induced behavioural and biochemical alterations, and was therefore also tested at 9 and 36 mg/kg. CPEE (100 mg/kg) and AF (36 mg/kg) exhibited maximum and significant (p < 0.05) attenuation of 3-NP induced alterations in comparison to 3-NP treated rats.

CONCLUSIONS

CPEE has a protective action against 3-NP induced HD like symptoms due to its strong antioxidant effect.