Exploring neuroprotective potential of Withania somnifera phytochemicals by inhibition of GluN2B-containing NMDA receptors: An in silico study

Phytotherapeutic options for the treatment of epilepsy: pharmacology, targets, and mechanism of action

Epilepsy is one of the most common, severe, chronic, potentially life-shortening neurological disorders, characterized by a persisting predisposition to generate seizures. It affects more than 60 million individuals globally, which is one of the major burdens in seizure-related mortality, comorbidities, disabilities, and cost. Different treatment options have been used for the management of epilepsy. More than 30 drugs have been approved by the US FDA against epilepsy. However, one-quarter of epileptic individuals still show resistance to the current medications. About 90% of individuals in low and middle-income countries do not have access to the current medication. In these countries, plant extracts have been used to treat various diseases, including epilepsy. These medicinal plants have high therapeutic value and contain valuable phytochemicals with diverse biomedical applications. Epilepsy is a multifactorial disease, and therefore, multitarget approaches such as plant extracts or extracted phytochemicals are needed, which can target multiple pathways. Numerous plant extracts and phytochemicals have been shown to treat epilepsy in various animal models by targeting various receptors, enzymes, and metabolic pathways. These extracts and phytochemicals could be used for the treatment of epilepsy in humans in the future; however, further research is needed to study the exact mechanism of action, toxicity, and dosage to reduce their side effects. In this narrative review, we comprehensively summarized the extracts of various plant species and purified phytochemicals isolated from plants, their targets and mechanism of action, and dosage used in various animal models against epilepsy.

In silico investigation of potential phytoconstituents against ligand- and voltage-gated ion channels as antiepileptic agents

The most promising anticonvulsant phytocompounds were explored in this work using docking, molecular dynamic (MD) simulation, and Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA) approaches. A total of 70 phytochemicals were screened against α-amino-3-hydroxyl-5-methyl-4-isoxazole propionic acid (AMPA), N-methyl-d-aspartate (NMDA), voltage-gated sodium ion channels (VGSC), and carbonic anhydrase enzyme II (CA II) receptors, and the docking results were compared to the reference drug phenytoin. Amentoflavone displayed the highest affinity for AMPA and VGSC receptors, with docking scores of - 10.4 and - 10.1 kcal/mol, respectively. Oliganthin H-NMDA and epigallocatechin-3-gallate-CA II complexes showed docking scores of - 10.9 and - 6.9 kcal/mol, respectively. All four complexes depicted a high dock score compared to the phenytoin complex at the binding site of the corresponding proteins. The MD simulation investigated the stabilities and favorable conformation of apoproteins and ligand/reference-bound complexes. The results revealed that proteins AMPA, VGSC, and CA II were more efficiently stabilized by lead phytochemicals than phenytoin binding. Additionally, principal component analysis and MM-PBSA results suggested that these lead phytocompounds have good compactness and strong binding free energy. Further, physicochemical and pharmacokinetic studies revealed that these final lead phytochemicals would be suitable for oral intake, have sufficient intestinal permeability, and have the ability to cross the blood-brain barrier (BBB). Comprehensively, this study predicted amentoflavone as the best lead phytochemical out of the 70 anticonvulsant phytocompounds that can be used to treat epilepsy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-03948-1.

Can Ashwagandha Benefit the Endocrine System?-A Review

Withania somnifera, also known as Ashwagandha, has been used in traditional medicine for thousands of years. Due to the wide range of its activities, there has been interest in its possible beneficial effects on the human body. It is proved that, among others, Ashwagandha has anti-stress, anti-inflammatory, antimicrobial, anti-cancer, anti-diabetic, anti-obesity, cardioprotective, and hypolipidemic properties. Particularly interesting are its properties reported in the field of psychiatry and neurology: in Alzheimer's disease, Parkinson's disease, multiple sclerosis, depression, bipolar disorder, insomnia, anxiety disorders and many others. The aim of this review is to find and summarize the effect that Ashwagandha root extract has on the endocrine system and hormones. The multitude of active substances and the wide hormonal problems faced by modern society sparked our interest in the topic of Ashwagandha's impact on this system. In this work, we also attempted to draw conclusions as to whether W. somnifera can help normalize the functions of the human endocrine system in the future. The search mainly included research published in the years 2010-2023. The results of the research show that Ashwagandha can have a positive effect on the functioning of the endocrine system, including improving the secretory function of the thyroid gland, normalizing adrenal activity, and multidirectional improvement on functioning of the reproductive system. The main mechanism of action in the latter appears to be based on the hypothalamus-pituitary-adrenal (HPA) axis, as a decrease in cortisol levels and an increase in hormones such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in men were found, which results in stress level reduction and improvement in fertility. In turn, other studies prove that active substances from W. somnifera, acting on the body, cause an increase in the secretion of triiodothyronine (T3) and thyroxine (T4) by the thyroid gland and a subsequent decrease in the level of thyroid-stimulating hormone (TSH) in accordance with the hypothalamus-pituitary-thyroid (HPT) axis. In light of these findings, it is clear that Ashwagandha holds significant promise as a natural remedy for various health concerns, especially those related to the endocrine system. Future research may provide new insights into its mechanisms of action and expand its applications in both traditional and modern medicine. The safety and toxicity of Ashwagandha also remain important issues, which may affect its potential use in specific patient groups.

Pro-neurogenic effects of Lilii Bulbus on hippocampal neurogenesis and memory

Lilii Bulbus, the bulb of tiger lily, has anti-oxidant and anti-tumorigenic properties. However, the effects of Lilii Bulbus on learning, memory, and hippocampal neurogenesis remain unknown. This study investigated whether water extract of Lilii Bulbus (WELB) affects memory ability and hippocampal neurogenesis. Behavioral analyses (Morris water maze and passive avoidance test), immunohistochemistry, cell proliferation assay, and immunoblot analysis were performed. WELB (50 and 100 mg/kg; for 14 days) enhanced memory retention and spatial memory in normal mice as well as in scopolamine-treated mice with memory deficits. Furthermore, the administration of WELB significantly increased the number of proliferating cells and surviving newborn cells in the dentate gyrus of the hippocampus in normal mice. We found that WELB has a pro-neurogenic effect by increasing the activation of brain-derived neurotrophic factor (BDNF)/cAMP response element-binding protein (CREB) and mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) in the hippocampus. Moreover, we confirmed that WELB (100 and 200 μg/ml) significantly increased NE-4 C and primary embryonic NSCs proliferation. Inhibition/knockdown of MEK/ERK blocked WELB-induced MEK/ERK phosphorylation and NSCs proliferation. Hence, MEK/ERK activation was required in WELB-induced NSCs proliferation. Our study demonstrates the first evidence for WELB promoting hippocampal neurogenesis and memory; pro-neurogenic activity may enhance brain plasticity, with implications for treating neurodegenerative diseases.

Neurodegenerative disorders: Assessing the impact of natural vs drug-induced treatment options

Neurodegenerative illnesses refer to the gradual, cumulative loss of neural activity. Neurological conditions are considered to be the second leading cause of mortality in the modern world and the two most prevalent ones are Parkinson's disease and Alzheimer's disease. The negative side effects of pharmaceutical use are a major global concern, despite the availability of many different treatments for therapy. We concentrated on different types of neurological problems and their influence on targets, in vitro, in vivo, and in silico methods toward neurological disorders, as well as the molecular approaches influencing the same, in the first half of the review. The bulk of the second half of the review focuses on the many categories of treatment possibilities, including natural and artificial. Nevertheless, herbal treatment solutions are piquing scholarly attention due to their anti-oxidative properties and accessibility. However, more quality investigations and innovations are undoubtedly needed to back up these conclusions.

Advances on Therapeutic Strategies for Alzheimer’s Disease: From Medicinal Plant to Nanotechnology

Alzheimer’s disease (AD) is a chronic dysfunction of neurons in the brain leading to dementia. It is characterized by gradual mental failure, abnormal cognitive functioning, personality changes, diminished verbal fluency, and speech impairment. It is caused by neuronal injury in the cerebral cortex and hippocampal area of the brain. The number of individuals with AD is growing at a quick rate. The pathology behind AD is the progress of intraneuronal fibrillary tangles, accumulation of amyloid plaque, loss of cholinergic neurons, and decrease in choline acetyltransferase. Unfortunately, AD cannot be cured, but its progression can be delayed. Various FDA-approved inhibitors of cholinesterase enzyme such as rivastigmine, galantamine, donepezil, and NDMA receptor inhibitors (memantine), are available to manage the symptoms of AD. An exhaustive literature survey was carried out using SciFinder’s reports from Alzheimer’s Association, PubMed, and Clinical Trials.org. The literature was explored thoroughly to obtain information on the various available strategies to prevent AD. In the context of the present scenario, several strategies are being tried including the clinical trials for the treatment of AD. We have discussed pathophysiology, various targets, FDA-approved drugs, and various drugs in clinical trials against AD. The goal of this study is to shed light on current developments and treatment options, utilizing phytopharmaceuticals, nanomedicines, nutraceuticals, and gene therapy.

Withaniasomnifera phytochemicals possess SARS-CoV-2 RdRp and human TMPRSS2 protein binding potential

Abstract

Coronavirus disease-19 (COVID-19) pandemic caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) has infected approximately 26 million people and caused more than 6 million deaths globally. Spike (S)-protein on the outer surface of the virus uses human trans-membrane serine protease-2 (TMPRSS2) to gain entry into the cell. Recent reports indicate that human dipeptidyl peptidase-4 inhibitors (DPP4 or CD26) could also be utilized to check the S-protein mediated viral entry into COVID-19 patients. RNA dependent RNA polymerase (RdRp) is another key virulence protein of SARS-CoV-2 life cycle. The study aimed to identify the potential anti-SARS-CoV-2 inhibitors present in Withania somnifera (Solanaceae) using computer aided drug discovery approach. Molecular docking results showed that flavone glycoside, sugar alcohol, and flavonoid present in W. somnifera showed - 11.69, - 11.61, - 10.1, - 7.71 kcal/mole binding potential against S-protein, CD26, RdRp, and TMPRSS2 proteins. The major standard inhibitors of the targeted proteins (Sitagliptin, VE607, Camostat mesylate, and Remdesivir) showed the - 7.181, - 6.6, - 5.146, and - 7.56 kcal/mole binding potential. Furthermore, the lead phytochemicals and standard inhibitors bound and non-bound RdRp and TMPRSS2 proteins were subjected to molecular dynamics (MD) simulation to study the complex stability and change in protein conformation. The result showed energetically favorable and stable complex formation in terms of RMSD, RMSF, SASA, Rg, and hydrogen bond formation. Drug likeness and physiochemical properties of the test compounds exhibited satisfactory results. Taken together, the present study suggests the presence of potential anti-SARS-CoV-2 phytochemicals in W. somnifera that requires further validation in in vitro and in vivo studies.

Graphical Abstract

Supplementary information

The online version contains supplementary material available at 10.1007/s42535-022-00404-4.

Alternative Therapy of Psychosis: Potential Phytochemicals and Drug Targets in the Management of Schizophrenia

Schizophrenia is a chronic mental and behavioral disorder characterized by clusters of symptoms including hallucinations, delusions, disorganized thoughts and social withdrawal. It is mainly contributed by defects in dopamine, glutamate, cholinergic and serotonergic pathways, genetic and environmental factors, prenatal infections, oxidative stress, immune system activation and inflammation. Management of schizophrenia is usually carried out with typical and atypical antipsychotics, but it yields modest benefits with a diversity of side effects. Therefore, the current study was designed to determine the phytochemicals as new drug candidates for treatment and management of schizophrenia. These phytochemicals alter and affect neurotransmission, cell signaling pathways, endocannabinoid receptors, neuro-inflammation, activation of immune system and status of oxidative stress. Phytochemicals exhibiting anti-schizophrenic activity are mostly flavonoids, polyphenols, alkaloids, terpenoids, terpenes, polypropanoids, lactones and glycosides. However, well-designed clinical trials are consequently required to investigate potential protective effect and therapeutic benefits of these phytochemicals against schizophrenia.

A review of dementia, focusing on the distinct roles of viral protein corona and MMP9 in dementia: Potential pharmacotherapeutic priorities

Dementia, in particular, is a defining feature of Alzheimer's and Parkinson's diseases. Because of the combination of motor and cognitive impairments, Parkinson's disease dementia (PDD) has a greater impact on affected people than Alzheimer's disease dementia (ADD) and others. If one family member develops dementia, the other members will suffer greatly in terms of social and occupational functioning. Currently, no relevant treatment is available based on an examination of the absolute pathophysiology of dementia. As a result, our objective of current review encouraged to look for dementia pharmacotherapy based on their pathogenesis. We systematically searched electronic databases such as PubMed, Scopus, and ESCI for information on the pathophysiology of demetia, as well as their treatment with allopathic and herbal medications. By modulating intermediate proteins, oxidative stress, viral protein corona, and MMP9 are etiological factors that cause dementia. The pathophysiology of ADD was described by two hypotheses: the amyloid cascade hypothesis and the tau and tangle hypothesis. ADD is caused by an increase in amyloid-beta (Aβ) and neurofibrillary tangles in the cerebrum. The viral protein corona (VPC) is more contagious and helps to form amyloid-beta (Aβ) plaques and neurofibrillary tangles in the cerebrum. Thioredoxin interacting protein (TXNIP) inside the BBB encourages Aβ to become more engaged. PDD is caused by decreased or absent dopamine secretion from nerve cells in the substantia nigra, as well as PRKN gene deletion/duplication mutations, and shift in the PRKN-PACRG organisation, all of which are linked to ageing. This article discussed the pathophysiology of dementia, as well as a list of herbal medications that can easily cross the BBB and have a therapeutic effect on dementia.

Sodium-calcium exchanger isoform-3 targeted Withania somnifera (L.) Dunal therapeutic intervention ameliorates cognition in the 5xFAD mouse model of Alzheimer's disease

The third isoform of the Na+-Ca2+ exchanger (NCX3) is crucial for a physiological fine-tuning of the Ca2+ fluxes in excitable tissues. In this view, the NCX3 accounts for the aberrant Ca2+ influx seen during neuronal excitotoxicity, such as in Alzheimer's disease (AD). However, little is known about NCX3 regulation and functional properties. Withania somnifera (L.) Dunal (W. somnifera), a traditional indigenous plant widely recognized for having numerous medicinal values, was undertaken to determine its potential therapeutic benefit against aggregated Aβ1-42-induced NCX3 dysregulation and the thereof cognition impairment in 5xFAD mice. The undertaken sourced dried roots of authenticated W. somnifera physicochemical compositional tests satisfied standards of pharmacognostic quality, and further phytochemical analysis of the roots methanol extract revealed the roots constitute several antioxidants. Following an intra-gastric gavage administration of synthesized W. somnifera roots methanolic extract from postnatal day 30 (P30) to P75, in vivo cognitional studies and then neurochemical examinations of the NCX3 expression level, Aβ plaque deposition, and antioxidant activities in the AD-associated brain regions of 4-month-old 5xFAD mice suggests that the oxidative stress normalizing effects of W. somnifera constituents, operating on the NCX3, may have a therapeutic role in the improvement of cognition in AD.

Natural withanolides, an update

Covering: March 2010 to December 2020. Previous review: Nat. Prod. Rep., 2011, 28, 705This review summarizes the latest progress and perspectives on the structural classification, biological activities and mechanisms, metabolism and pharmacokinetic investigations, biosynthesis, chemical synthesis and structural modifications, as well as future research directions of the promising natural withanolides. The literature from March 2010 to December 2020 is reviewed, and 287 references are cited.

Design and Synthesis of New Withaferin A Inspired Hedgehog Pathway Inhibitors

Withanolides constitute a well-known family of plant-based alkaloids characterised by widespread biological properties, including the ability of interfering with Hedgehog (Hh) signalling pathway. Following our interest in natural products and in anticancer compounds, we report here the synthesis of a new class of Hh signalling pathway inhibitors, inspired by withaferin A, the first isolated member of withanolides. The decoration of our scaffolds was rationally supported by in silico studies, while functional evaluation revealed promising candidates, confirming once again the importance of natural products as inspiration source for the discovery of novel bioactive compounds. A stereoselective approach, based on Brown chemistry, allowed the obtainment and the functional evaluation of the enantiopure hit compounds.

Computational investigation of phytochemicals from Withania somnifera (Indian ginseng/ashwagandha) as plausible inhibitors of GluN2B-containing NMDA receptors

N-Methyl-d-aspartate receptor (NMDAR)-mediated excitotoxicity has been implicated in multi-neurodegenerative diseases. Owing to dearth of efficacy and adverse effects of NMDA receptor antagonists, search for herbal remedies acting like salutary agents is a dynamic expanse of investigation to contest neurodegenerative disease. Withania somnifera (W. somnifera) has been used since antiquity as a nerve tonic and nootropic agents in Ayurveda, an old Indian system of medicine. In the present study, we have explored phytochemicals from Ayurvedic herb W. somnifera as an inhibitor of NMDA receptor-mediated excitotoxicity through allosteric reticence of the GluN1-GluN2B encompassing NMDARs by dint of molecular docking and dynamics studies. Thus, steering and constraining GluN1-GluN2B may be effective in the management of neurodegenerative diseases including Alzheimer's disease. Out of the curtained phytochemicals, chlorogenic acid revealed significant docking scores of -8.856 and -8.645 kcal/mol and free binding energies of -49.84 and -50.67 kcal/mol in Chain AB and Chain CD of NMDARs, respectively. Chlorogenic acid in AB chain forms four hydrogen bonding with Glu110, Arg115, Leu135 and Asp136 amino acid residues and five hydrogen bond with Glu106, Ala107, Ile133, Ile335and Arg155 amino acid residues of CD chain. To further validate the interaction of top scored molecule chlorogenic acid, molecular dynamics study of 100 ns was carried out. It indicated that the protein-ligand complex was stable throughout the simulation period, and minimal backbone fluctuations have ensued in the system. In silico pharmacokinetic predictions of the screened phytochemicals were within the defined range described for human use.Communicated by Ramaswamy H. Sarma.

In silico discovery and evaluation of phytochemicals binding mechanism against human catechol-O-methyltransferase as a putative bioenhancer of L-DOPA therapy in Parkinson disease

Levodopa (L-DOPA) therapy is normally practised to treat motor pattern associated with Parkinson disease (PD). Additionally, several inhibitory drugs such as Entacapone and Opicapone are also cosupplemented to protect peripheral inactivation of exogenous L-DOPA (~80%) that occurs due to metabolic activity of the enzyme catechol-O-methyltransferase (COMT). Although, both Entacapone and Opicapone have U.S. Food and Drug Administration approval but regular use of these drugs is associated with high risk of side effects. Thus, authors have focused on in silico discovery of phytochemicals and evaluation of their effectiveness against human soluble COMT using virtual screening, molecular docking, drug-like property prediction, generation of pharmacophoric property, and molecular dynamics simulation. Overall, study proposed, nine phytochemicals (withaphysalin D, withaphysalin N, withaferin A, withacnistin, withaphysalin C, withaphysalin O, withanolide B, withasomnine, and withaphysalin F) of plant Withania somnifera have strong binding efficiency against human COMT in comparison to both of the drugs i.e., Opicapone and Entacapone, thus may be used as putative bioenhancer in L-DOPA therapy. The present study needs further experimental validation to be used as an adjuvant in PD treatment.

Metabolomics of Withania somnifera (L.) Dunal: Advances and applications

ETHNOPHARMACOLOGICAL RELEVANCE

Withania somnifera L. (Solanaceae), commonly known as Ashwagandha or Indian ginseng, is used in Ayurveda (Indian system of traditional medicine) for vitality, cardio-protection and treating other ailments, such as neurological disorders, gout, and skin diseases.

AIM OF THE REVIEW

We present a critical overview of the information on the metabolomics of W. somnifera and highlight the significance of the technique for use in quality control of medicinal products. We have also pointed out the use of metabolomics to distinguish varieties and to identify best methods of cultivation, collection, as well as extraction.

MATERIAL AND METHODS

The relevant information on medicinal value, phytochemical studies, metabolomics of W. somnifera, and their applications were collected from a rigorous electronic search through scientific databases, including Scopus, PubMed, Web of Science and Google Scholar. Structures of selected metabolites were from the PubChem.

RESULTS

The pharmacological activities of W. somnifera were well documented. Roots are the most important parts of the plant used in Ayurvedic preparations. Stem and leaves also have a rich content of bioactive phytochemicals like steroidal lactones, alkaloids, and phenolic acids. Metabolomic studies revealed that metabolite profiles of W. somnifera depended on plant parts collected and the developmental stage of the plant, besides the season of sample collection and geographical location. The levels of withanolides were variable, depending on the morpho/chemotypes within the species of W. somnifera. Although studies on W. somnifera were initiated several years ago, the complexity of secondary metabolites was not realized due to the lack of adequate and fool-proof technology for phytochemical fingerprinting. Sophistications in chromatography coupled to mass spectrometry facilitated the discovery of several new metabolites. Mutually complementary techniques like LC-MS, GC-MS, HPTLC, and NMR were employed to obtain a comprehensive metabolomic profile. Subsequent data analyses and searches against spectral databases enabled the annotation of signals and dereplication of metabolites in several numbers without isolating them individually.

CONCLUSIONS

The present review provides a critical update of metabolomic data and the diverse application of the technique. The identification of parameters for standardization and quality control of herbal products is essential to facilitate mandatory checks for the purity of formulation. Such studies would enable us to identify the best geographical location of plants and the time of collection. We recommend the use of metabolomic analysis of herbal products based on W. somnifera for quality control as well as the discovery of novel bioactive compounds.

Casuarictin: A new herbal drug molecule for Alzheimer's disease as inhibitor of presenilin stabilization factor like protein

Alzheimer's disease is a progressive neurodegenerative disorder. In this disease neurodegeneration occurs due to deposition of aggregated amyloid-beta plaques and neurofibrillary tangles (hyperphosphorylated tau proteins). Present study focuses on interaction of different phytochemicals with presenilin stabilization factor like protein (PSFL). PSFL protein is known to stabilize Presenilin, which is mainly involved in intramembrane hydrolysis of selected type- I membrane proteins, including amyloid-beta precursor protein, and produces amyloid-beta protein. Amyloid-beta are small peptides comprising of 36–43 amino acids, which play a significant role in senile plaques formation in the brains of Alzheimer patients. Virtual screening and docking of phytochemicals with PSFL protein was done to find the potential inhibitor. Based on binding affinity, docked energy and molecular dynamics simulations, three phytochemicals namely Saponin, Casuarictin, and Enoxolone, were identified as potential inhibitors for the target protein.

Investigating 11 Withanosides and Withanolides by UHPLC-PDA and Mass Fragmentation Studies from Ashwagandha (Withania somnifera)

Withania somnifera (WS), also known as ashwagandha or Indian ginseng, is known for its pharmacological significance in neurodegenerative diseases, stress, cancer, immunomodulatory, and antiviral activity. In this study, the WS extract (WSE) from the root was subjected to ultrahigh-performance liquid chromatography with photodiode array detection (UHPLC-PDA) analysis to separate 11 withanoside and withanolide compounds. The quantification validation was carried out as per ICHQ2R1 guidelines in a single methodology. The calibration curves were linear (r ² > 0.99) for all 11 compounds within the tested concentration ranges. The limits of detection and quantification were in the range of 0.213-0.362 and 0.646-1.098 μg/mL, respectively. The results were precise (relative standard deviation, <5.0%) and accurate (relative error, 0.01-0.76). All compounds showed good recoveries of 84.77-100.11%. For the first time, withanoside VII, 27-hydroxywithanone, dihydrowithaferin A, and viscosalactone B were quantified and validated along with bioactive compounds withanoside IV, withanoside V, withaferin A, 12-deoxywithastramonolide, withanolide A, withanone, and withanolide B simultaneously in WS. This UHPLC-PDA method has practical adaptability for ashwagandha raw material, extract, and product manufacturers, along with basic and applied science researchers. The method has been developed on UHPLC for routine analysis. The 11 withanosides and withanolides were confirmed using the fragmentation pattern obtained by the combined use of electrospray ionization and collision-induced dissociation in triple-quadrupole tandem mass spectrometry (TQ-MS/MS) in the WSE.

Network Pharmacology-Based Approach to Revealing Biological Mechanisms of Qingkailing Injection against IschemicStroke: Focusing on Blood-Brain Barrier

Ischemic stroke is the most common type of cerebrovascular accident worldwide. It causes long-term disability and death. Qingkailing (QKL) injection is a traditional Chinese patent medicine which has been clinically applied in the treatment of ischemic stroke for nearly thirty years. In the present study, network pharmacology combined with experimentation was used to elucidate the mechanisms of QKL. ADME screening and target prediction identified 62 active compounds and 275 targets for QKL. Topological screening of the protein-protein interaction (PPI) network was used to build a core PPI network consisting of 408 nodes and 17,830 edges. KEGG enrichment indicated that the main signaling pathway implicated in ischemic stroke involved hypoxia-inducible factor-1 (HIF-1). Experimentation showed that QKL alleviated neurological deficits, brain infraction, blood-brain barrier (BBB) leakage, and tight junction degeneration in a mouse ischemic stroke model. Two-photon laser scanning microscopy was used to evaluate BBB permeability and cerebral microvessel structure in living mice. HIF-1α, matrix metalloproteinase-9 (MMP-9), and tight junction proteins such as occludin, zonula occludins-1 (ZO-1), claudin-5, and VE-Cadherin were measured by western blotting. QKL upregulated ZO-1 and downregulated HIF-1α and MMP-9. QKL has a multiapproach, multitarget, and synergistic effect against ischemic stroke.

Ashwagandha in brain disorders: A review of recent developments

ETHNOPHARMACOLOGICAL RELEVANCE

Withania somnifera (Family: Solanaceae), commonly known as Ashwagandha or Indian ginseng is distributed widely in India, Nepal, China and Yemen. The roots of plant consist of active phytoconstituents mainly withanolides, alkaloids and sitoindosides and are conventionally used for the treatment of multiple brain disorders.

AIM OF THE REVIEW

This review aims to critically assess and summarize the current state and implication of Ashwagandha in brain disorders. We have mainly focussed on the reported neuroactive phytoconstituents, available marketed products, pharmacological studies, mechanism of action and recent patents published related to neuroprotective effects of Ashwagandha in brain disorders.

MATERIALS AND METHODS

All the information and data was collected on Ashwagandha using keywords "Ashwagandha" along with "Phytoconstituents", "Ayurvedic, Unani and Homeopathy marketed formulation", "Brain disorders", "Mechanism" and "Patents". Following sources were searched for data collection: electronic scientific databases such as Science Direct, Google Scholar, Elsevier, PubMed, Wiley On-line Library, Taylor and Francis, Springer; books such as AYUSH Pharmacopoeia; authentic textbooks and formularies.

RESULTS

Identified neuroprotective phytoconstituents of Ashwagandha are sitoindosides VII-X, withaferin A, withanosides IV, withanols, withanolide A, withanolide B, anaferine, beta-sitosterol, withanolide D with key pharmacological effects in brain disorders mainly anxiety, Alzheimer's, Parkinson's, Schizophrenia, Huntington's disease, dyslexia, depression, autism, addiction, amyotrophic lateral sclerosis, attention deficit hyperactivity disorder and bipolar disorders. The literature survey does not highlight any toxic effects of Ashwagandha. Further, multiple available marketed products and patents recognized its beneficial role in various brain disorders; however, very few data is available on mechanistic pathway and clinical studies of Ashwagandha for various brain disorders is scarce and not promising.

CONCLUSION

The review concludes the results of recent studies on Ashwagandha suggesting its extensive potential as neuroprotective in various brain disorders as supported by preclinical studies, clinical trials and published patents. However vague understanding of the mechanistic pathways involved in imparting the neuroprotective effect of Ashwagandha warrants further study to promote it as a promising drug candidate.

Total Synthesis of (-)-Anaferine: A Further Ramification in a Diversity-Oriented Approach

The piperidine ring is a widespread motif in several natural bioactive alkaloids of both vegetal and marine origin. In the last years, a diversity-oriented synthetic (DOS) approach, aimed at the generation of a library of piperidine-based derivatives, was developed in our research group, employing commercially available 2-piperidine ethanol as a versatile precursor. Here, we report the exploration of another ramification of our DOS approach, that led us to the stereoselective total synthesis of (–)-anaferine, a bis-piperidine alkaloid present in Withania somnifera extract. This natural product was obtained in 9% overall yield over 13 steps, starting from a key homoallylic alcohol previously synthesised in our laboratory. Therefore, the collection of piperidine-derivatives accessible from 2-piperidine ethanol was enriched with a new, diverse scaffold.

Natural Products and Their Bioactive Compounds: Neuroprotective Potentials against Neurodegenerative Diseases

In recent years, natural products, which originate from plants, animals, and fungi, together with their bioactive compounds have been intensively explored and studied for their therapeutic potentials for various diseases such as cardiovascular, diabetes, hypertension, reproductive, cancer, and neurodegenerative diseases. Neurodegenerative diseases, including Alzheimer's disease, Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis are characterized by the progressive dysfunction and loss of neuronal structure and function that resulted in the neuronal cell death. Since the multifactorial pathological mechanisms are associated with neurodegeneration, targeting multiple mechanisms of actions and neuroprotection approach, which involves preventing cell death and restoring the function to damaged neurons, could be promising strategies for the prevention and therapeutic of neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for the treatment of neurodegenerative diseases. This review focused on the therapeutic potential of natural products and their bioactive compounds to exert a neuroprotective effect on the pathologies of neurodegenerative diseases.

An update on the efficacy of anti-inflammatory agents for patients with schizophrenia: a meta-analysis

BACKGROUND

Accumulating evidence shows that a propensity towards a pro-inflammatory status in the brain plays an important role in schizophrenia. Anti-inflammatory drugs might compensate this propensity. This study provides an update regarding the efficacy of agents with some anti-inflammatory actions for schizophrenia symptoms tested in randomized controlled trials (RCTs).

METHODS

PubMed, Embase, the National Institutes of Health website (http://www.clinicaltrials.gov), and the Cochrane Database of Systematic Reviews were systematically searched for RCTs that investigated clinical outcomes.

RESULTS

Our search yielded 56 studies that provided information on the efficacy of the following components on symptom severity: aspirin, bexarotene, celecoxib, davunetide, dextromethorphan, estrogens, fatty acids, melatonin, minocycline, N-acetylcysteine (NAC), pioglitazone, piracetam, pregnenolone, statins, varenicline, and withania somnifera extract. The results of aspirin [mean weighted effect size (ES): 0.30; n = 270; 95% CI (CI) 0.06-0.54], estrogens (ES: 0.78; n = 723; CI 0.36-1.19), minocycline (ES: 0.40; n = 946; CI 0.11-0.68), and NAC (ES: 1.00; n = 442; CI 0.60-1.41) were significant in meta-analysis of at least two studies. Subgroup analysis yielded larger positive effects for first-episode psychosis (FEP) or early-phase schizophrenia studies. Bexarotene, celecoxib, davunetide, dextromethorphan, fatty acids, pregnenolone, statins, and varenicline showed no significant effect.

CONCLUSIONS

Some, but not all agents with anti-inflammatory properties showed efficacy. Effective agents were aspirin, estrogens, minocycline, and NAC. We observed greater beneficial results on symptom severity in FEP or early-phase schizophrenia.

Highly convergent total synthesis of (+)-anaferine and (−)-dihydrocuscohygrine

The total synthesis of (+)-anaferine and (−)-dihydrocuscohygrine is described. Bidirectional cross metathesis/double intramolecular aza-Michael reactions were the key steps.

Pharmacokinetics and brain penetration study of chlorogenic acid in rats

1. The present study is designed to investigate the brain distribution and plasma pharmacokinetics profiles of chlorogenic acid (CGA) after intranasal administration in Charles-Foster rats to evaluate whether the CGA molecules are transported directly via the nose-to-brain path. 2. The CGA is administered intravenously (IV) and intranasally (IN) at the dose of 10 mg/kg. Further, its concentration in the plasma, cerebrospinal fluid (CSF) and the whole brain is analyzed by HPLC-UV method. 3. The study observes that CGA is rapidly absorbed in plasma with t_max of 1 min similar to IV route after IN administration. The peak plasma concentration and AUC_0-24 are higher by 3.5 and 4.0 times respectively in IV administration, compared to IN delivery that represents the significant less systemic exposure of CGA in IN route. 4. However, the concentration of CGA in the brain is 4, 6.5, 5.3, 5.2 and 4.5 times higher at 30, 60, 120, 240 and 360 min, respectively in IN administration compared to IV administration. The exposure of CGA in the brain after IN administration (AUC_{brain, IN}) was significantly greater (4 times) as compared to the exposure of CGA in the brain (AUC_{brain, IV}) after IV administration reflecting significant brain uptake of CGA through nasal route. Therefore, IN delivery of CGA can be a promising approach for the treatment of stroke and neurodegenerative disorders.

Molecular docking, QSAR and ADMET based mining of natural compounds against prime targets of HIV

AIDS is one of the multifaceted diseases and this underlying complexity hampers its complete cure. The toxicity of existing drugs and emergence of multidrug-resistant virus makes the treatment worse. Development of effective, safe and low-cost anti-HIV drugs is among the top global priority. Exploration of natural resources may give ray of hope to develop new anti-HIV leads. Among the various therapeutic targets for HIV treatment, reverse transcriptase, protease, integrase, GP120, and ribonuclease are the prime focus. In the present study, we predicted potential plant-derived natural molecules for HIV treatment using computational approach, i.e. molecular docking, quantitative structure activity relationship (QSAR), and ADMET studies. Receptor-ligand binding studies were performed using three different software for precise prediction - Discovery studio 4.0, Schrodinger and Molegrow virtual docker. Docking scores revealed that Mulberrosides, Anolignans, Curcumin and Chebulic acid are promising candidates that bind with multi targets of HIV, while Neo-andrographolide, Nimbolide and Punigluconin were target-specific candidates. Subsequently, QSAR was performed using biologically proved compounds which predicted the biological activity of compounds. We identified Anolignans, Curcumin, Mulberrosides, Chebulic acid and Neo-andrographolide as potential natural molecules for HIV treatment from results of molecular docking and 3D-QSAR. In silico ADMET studies showed drug-likeness of these lead molecules. Structure similarities of identified lead molecules were compared with identified marketed drugs by superimposing both the molecules. Using in silico studies, we have identified few best fit molecules of natural origin against identified targets which may give new drugs to combat HIV infection after wet lab validation.

Synthesis of withasomnine and pyrazole derivatives via intramolecular dehydrogenative cyclization, as well as biological evaluation of withasomnine-based scaffolds

Synthesis of a withasomnine-inspired library which shows anticancer reactivities and COX-2 inhibition via an intramolecular dehydrogenative cyclization process.

Identification of potential inhibitors of PARP-1, a regulator of caspase-independent cell death pathway, from Withania somnifera phytochemicals for combating neurotoxicity: A structure-based in-silico study

Poly (ADP-ribose) polymerase-1 (PARP-1) reverses DNA damage by repairing DNA nicks and breaks in the normal cellular environment. However, during abnormal conditions like stroke and other neurological disorders, overactivation of PARP-1 leads to neuronal cell death via a caspase-independent programmed cell death pathway. Strategies involving inhibition or knockout of PARP-1 have proved beneficial in combating neuro-cytotoxicity. In this study, we performed in-silico analysis of 27 phytochemicals of Withania somnifera (Ashwagandha), to investigate their inhibition efficiency against PARP-1. Out of 27 phytochemicals, we report 12 phytochemicals binding to the catalytic domain of PARP-1 with an affinity higher than FR257517, PJ34 and Talazoparib (highly potent inhibitors of the enzyme). Among these 12 compounds, five phytochemicals namely Stigmasterol, Withacnistin, Withaferin A, Withanolide G and Withanolide B show an exceptionally high binding affinity for the catalytic domain of PARP-1 and bind to the enzyme with similar hydrogen bond formation and hydrophobic interaction pattern as their inhibitors. All of these phytochemicals are BBB permeable so that they can be further developed into potential future neuro-therapeutic drugs against neurodegenerative disorders involving neuronal cell death.

Withania somniferaphytochemicals confer neuroprotection by selective inhibition of nNos: Anin silicostudy to search potent and selective inhibitors for human nNOS

Neuronal nitric oxide synthase (nNOS or NOS1) is an important therapeutic target for the treatment of various neurological diseases. A major challenge faced in the design of nNOS inhibitors emphasizes on potency in humans and selectivity over other NOS isoforms — eNOS and iNOS. The present structural-based in silico study was carried out to search potent and selective inhibitor for human nNOS from a set of 40 Withania somnifera phytochemicals structure. Ten phytochemicals appear as dual-selective inhibitors of nNOS over both iNOS and eNOS. Here we report five potent and selective human nNOS inhibitors, namely, Chlorogenic Acid, Withanolide B, Withacnistin Pelletierine, and Calystegine B2 based on their selectivity, binding energy and nNOS active site residues interaction profile. These phytochemicals have nNOS selectivity higher than 4-methyl-6-(2-(5-(3-(methylamino)propyl)pyridin-3-yl)-ethyl)pyridin-2-amine inhibitor and have potential as an oral neurotherapeutic agent to combat neurological disorders mediated by nNOS activation.

Inhibition of Gelatinases (MMP-2 and MMP-9) by Withania somnifera Phytochemicals Confers Neuroprotection in Stroke: An In Silico Analysis

A stroke or cerebrovascular accident is a serious, life-threatening medical condition that occurs when the blood supply to part of the brain is severely reduced or cut off, depriving brain tissue of oxygen and nutrients. Studies suggested that level of gelatinases (MMP-2 and MMP-9) usually increases in the brain after stroke. The elevated activity of gelatinases plays the deleterious role in ischemic stroke, hemorrhagic stroke and perinatal hypoxic-ischemic brain injury. Therefore, matrix metalloproteinase (MMP)-2 and MMP-9 inhibition have therapeutic importance in stroke condition. Present in silico study investigates whether Withania somnifera (WS) phytochemicals inhibit the MMP-2 and MMP-9 by binding to the catalytic domain, as similar to their inhibitor or not. For that, we performed molecular docking study to evaluate the gelatinases-inhibitory potential of 36 WS phytochemicals, which compared with gelatinases inhibitors viz. hydroxamic acid, quercetin, doxycycline, minocycline and reverse hydroxamate. The results suggest that 28 out of 36 WS phytochemicals show higher affinity for MMP-2 owing to bind with active site residues of S1'-pocket with lower binding energy and smaller inhibition constant (Ki) than considered inhibitors. As well as, withanolide G and withafastuosin E show higher affinity for MMP-9 than reverse hydroxamate inhibitor. These phytochemicals have neuroprotective potential as an inherently useful oral drug to combat ischemic and hemorrhagic stroke mediated by gelatinases.