Editorial: Natural Products-Based Drugs: Potential Therapeutics Against Alzheimer's Disease and Other Neurological Disorders

Metabolic Profiling of a Mediterranean-Inspired (Poly)phenol-Rich Mixture in the Brain: Perfusion Effect and In Vitro Blood-Brain Barrier Transport Validation

A Mediterranean diet rich in (poly)phenols has been linked to neuroprotection, but its effects likely depend on the ability of phenolic metabolites to cross the blood-brain barrier (BBB). This study evaluated the kinetics plasma and brain distribution of phenolic metabolites in Sprague-Dawley rats following oral administration of a polyphenol-rich extract mixture from Mediterranean foods (pomegranate, lemon, orange, grape, and olive). UPLC-ESI-QTOF analyses revealed 39 phenolic-derived metabolites in plasma, of which 20 were in nonperfused (NPB) and 19 in perfused brains (PB), including hydroxytyrosol and tyrosol sulfates, ellagic acid, dihydrocaffeic acid, and derived metabolites. Kinetic data showed substantially higher plasma metabolite concentrations than the brain, with slightly higher levels in NPB. The BBB transport efficiency of phenolic metabolites was validated in vitro using human brain microvascular endothelial cells (HBMECs), showing improved transport when tested as mixtures. These findings confirm that circulating phenolic metabolites from Mediterranean foods can reach brain tissues, contributing to preventing neurodegenerative diseases.

Natural compounds as therapeutic candidates for spinocerebellar ataxia type 1: a computational approach

Spinocerebellar Ataxia Type 1 (SCA1) is a progressive neurodegenerative disorder caused by the expansion and aggregation of polyglutamine (polyQ) in the Ataxin-1 (ATXN1) protein, leading to severe neuronal dysfunction. Currently, only symptomatic treatments are available, highlighting the requirement for disease-modifying therapies. This study employed a detailed in silico approach to identify potential neuroprotective natural compounds targeting the Ataxin-1 protein implicated in SCA1. The three-dimensional structure of Ataxin-1 was retrieved, validated, and optimized to achieve a stable structural model. Validation using a Ramachandran plot indicated that 77% of the residues were in favored regions, confirming the reliability of the protein structure. Active site residues were identified using CASTp, and receptor grids were generated for molecular docking studies. A library of 50 natural compounds was screened, among which 21 satisfied Lipinski's rule of five. Molecular docking using PyRx and AutoDock 4.2 identified Withanolide A as the top candidate, exhibiting the highest binding affinity (- 10.14 kcal/mol) and forming four hydrogen bonds with key active site residues. The top six ligands were further assessed for ADMET properties, with Withanolide A showing optimal drug-likeness, high gastrointestinal and blood-brain absorption, and non-toxic profiles. Molecular dynamics simulations over 200 ns demonstrated the stability of the Ataxin-1-Withanolide A complex, supported by RMSD, RMSF, RoG, and SASA analyses. PCA revealed reduced conformational flexibility, indicating enhanced structural stability of the ligand-bound complex. Additionally, MM-PBSA analysis confirmed that Van der Waals interactions were the primary stabilizing forces, complemented by electrostatic contributions. This integrated computational approach highlights the therapeutic potential of Withanolide A as a neuroprotective agent for SCA1, providing a base for future experimental validation and drug development.

Graphical abstract

Bromelain Protects Against PTZ-Induced Glial Damage and Inflammation: An In Vitro and In Silico Study

This study aimed to investigate how bromelain protects glial cells from pentylenetetrazole (PTZ)-induced damage, focusing on its anti-inflammatory effects. C6 glioma cells were treated with PTZ, bromelain, or a combination of PTZ and bromelain. The interactions of bromelain with iNOS (Inducible Nitric Oxide Synthase) and COX2 (Cyclooxygenase-2) were investigated using molecular docking calculations. Cell viability was measured using the XTT (Methoxynitrosulfophenyl-Tetrazolium Carboxanilide) assay. iNOS, NO (Nitric Oxide), and COX2 levels were assessed using ELISA and immunofluorescence staining. Bromelain at 50 and 100 µg/mL significantly increased cell viability (p < 0.001). On the other hand, bromelain at 50 µg/mL reduced inflammation, as indicated by lower levels of NO, iNOS, and COX2 (p < 0.001). In-silico predictions suggest that bromelain can effectively target iNOS and COX2, key inflammatory proteins. These findings indicate that bromelain protects glial cells by exerting anti-inflammatory effects. However, further research is needed to understand the underlying mechanisms fully.

Embelin Mitigates Amyloid-β-Induced Neurotoxicity and Cognitive Impairment in Rats: Potential Therapeutic Implications for Alzheimer's Disease

Alzheimer's disease (AD) is a significant form of dementia. Embelin (EMB) is a natural compound with varied actions that could help prevent AD pathology. Herein, we have investigated the neuroprotective potential of EMB against Aβ1-42-induced neurotoxicity in rats. In this experiment, Alzheimer-like dementia was induced in rats by infusing Aβ1-42 oligomers directly into the brain's ventricles. Subsequently, the Aβ1-42-intoxicated rats received treatment with varying doses of EMB (2.5, 5, and 10 mg/kg, administered intraperitoneally) over 2 weeks. The spatial and non-spatial memory of animals was assessed at different time intervals, and various biochemical, neurochemical, and neuroinflammatory parameters in the hippocampal brain tissue of the rats were analyzed. Infusion of Aβ1-42 in rat brain caused cognitive impairment and was accompanied by increased acetylcholinesterase activity, oxidative stress, and elevated levels of pro-inflammatory cytokines (such as TNF-α, IL-1β, and IL-6) in the hippocampal tissue. Moreover, a significant decline in the levels of monoamines and an imbalance of GABA and glutamate levels were also observed. EMB treatment significantly mitigated Aβ1-42-induced cognitive deficit and other biochemical changes, including Aβ levels. The EMB-treated rats showed improved learning and consolidation of memory. EMB also attenuated Aβ-induced oxidative stress and neuroinflammation and restored the levels of monoamines and the balance between GABA and glutamate. The observed cognitive benefits following EMB treatment in Aβ1-42-infused rats may be attributed to its antioxidant and anti-inflammatory properties and ability to restore hippocampal neurochemistry and Aβ levels. The above findings indicate the therapeutic potential of EMB in neurodegenerative pathologies associated with cognitive decline, such as Alzheimer's disease.

Mechanistic insight into neuroprotective effect of standardized ginger chemo varieties from Manipur, India in scopolamine induced learning and memory impaired mice

Alzheimer's disease is a complex neurodegenerative disease characterized by progressive decline in cognitive function and behaviour. Ginger is the rhizome of the plant Zingiber officinale Roscoe, has been an important ingredient of many Ayurveda formulations to treat neurological disorders. The present study aims to estimate the variation of 6-gingerol content in nine different ginger samples collected from Manipur, India, investigate the neuroprotective potential of the most potent ginger sample against scopolamine-induced cognitively impaired mice, and validate the therapeutic claim by molecular docking analysis. High Performance Thin Layer Chromatography (HPTLC) analysis suggested that the sample GV6 had the highest 6-gingerol content with potent in vitro acetylcholnesterase (AChE) (IC50 = 336.10 µg/mL) and butyrylcholinesterase (BChE) (IC50 = 411.73 µg/mL) enzyme inhibitory activity. The neuroprotective potential of GV6 was tested in scopolamine-induced cognitively impaired mice (200 and 400 mg/kg). The behavioral analysis showed that GV6 alleviated the spatial recognition, and short-term and long-term memory in the experimental mice model. GV6 significantly improved brain AChE and BChE activity, acetylcholine (ACh) level, markedly alleviated the antioxidant parameters, and reversed the neuroinflammation. Brain histopathological observations confirmed the presence of organized nerve fibers, improvement of neuronal cell density, and reverse the nucleus shrinkage. Further molecular docking analysis showed that 6-gingerol and galantamine exhibited stable interaction with AChE (-7.5 and - 7.3 kcaL/moL) and BChE (-7.3 and - 8.5 kcaL/moL). The present study emphasizes the quality-related therapeutic importance of ginger samples from Northeast India and demonstrates that administration of GV6 may improve brain cognitive functions by restoring neurotransmitter levels and inflammatory and antioxidant parameters in scopolamine-induced cognitively impaired mice.

Phytochemicals-based β-amyloid cleaving enzyme-1 and MAO-B inhibitors for the treatment of Alzheimer's disease: molecular simulations-based predictions

Alzheimer's disease (AD) is among the highly prevalent neurodegenerative disorder of the aging brain and is allied with cognitive and behavioral abnormalities. Unfortunately, there is very limited drug discovery for the effective management of AD, and the clinically approved drugs have limited efficacy. Consequently, there is an immediate demand for the development of new compounds that have the ability to act as multitarget-directed ligands (MTDLs). As major pathological targets of the disease, the current study aimed to investigate lead natural bioactive compounds including apigenin, epigallocatechin-3-gallate, berberine, curcumin, genistein, luteolin, quercetin, resveratrol for their inhibitory potentials against β-amyloid cleaving enzyme-1 (BACE1) and monoamine oxidase-B (MAO-B) enzymes. The study compounds were docked against the target enzymes (MAO-B and BACE1) using MOE software and subsequent molecular dynamics simulations (MDS) studies. The molecular docking analysis revealed that these phytochemicals (MTDLs) showed good interactions with the target enzymes as compared to the reference inhibitors. Among these eight phytocompounds, the epigallocatechin-3-gallate compound was an active inhibitor against both drug targets, with the highest docking scores and good interactions with the active residues of the enzymes. Furthermore, the docking result of the active one inhibitor in complex with the target enzymes (epigallocatechin-3-gallate/BACE1, epigallocatechin-3-gallate/MAO-B, reference/BACE1 and reference/MAO-B) were further validated by MDS. According to the findings of our study, epigallocatechin-3-gallate has the potential to be a candidate for use in the treatment of neurological illnesses like AD. This compound has MTDL potential and may be exploited to create new compounds with disease-modifying features.Communicated by Ramaswamy H. Sarma.

Metabolites profiling, in-vitro and molecular docking studies of five legume seeds for Alzheimer's disease

Even though legumes are valuable medicinal plants with edible seeds that are extensively consumed worldwide, there is little information available on the metabolic variations between different dietary beans and their influence as potential anti-cholinesterase agents. High-resolution liquid chromatography coupled with mass spectrometry in positive and negative ionization modes combined with multivariate analysis were used to explore differences in the metabolic profiles of five commonly edible seeds, fava bean, black-eyed pea, kidney bean, red lentil, and chickpea. A total of 139 metabolites from various classes were identified including saponins, alkaloids, phenolic acids, iridoids, and terpenes. Chickpea showed the highest antioxidant and anti-cholinesterase effects, followed by kidney beans. Supervised and unsupervised chemometric analysis determined that species could be distinguished by their different discriminatory metabolites. The major metabolic pathways in legumes were also studied. Glycerophospholipid metabolism was the most significantly enriched KEGG pathway. Pearson's correlation analysis pinpointed 18 metabolites that were positively correlated with the anti-cholinesterase activity. Molecular docking of the biomarkers to the active sites of acetyl- and butyryl-cholinesterase enzymes revealed promising binding scores, validating the correlation results. The present study will add to the metabolomic analysis of legumes and their nutritional value and advocate their inclusion in anti-Alzheimer's formulations.

Alzheimer's disease: a review on the current trends of the effective diagnosis and therapeutics

The most prevalent cause of dementia is Alzheimer's disease. Cognitive decline and accelerating memory loss characterize it. Alzheimer's disease advances sequentially, starting with preclinical stages, followed by mild cognitive and/or behavioral impairment, and ultimately leading to Alzheimer's disease dementia. In recent years, healthcare providers have been advised to make an earlier diagnosis of Alzheimer's, prior to individuals developing Alzheimer's disease dementia. Regrettably, the identification of early-stage Alzheimer's disease in clinical settings can be arduous due to the tendency of patients and healthcare providers to disregard symptoms as typical signs of aging. Therefore, accurate and prompt diagnosis of Alzheimer's disease is essential in order to facilitate the development of disease-modifying and secondary preventive therapies prior to the onset of symptoms. There has been a notable shift in the goal of the diagnosis process, transitioning from merely confirming the presence of symptomatic AD to recognizing the illness in its early, asymptomatic phases. Understanding the evolution of disease-modifying therapies and putting effective diagnostic and therapeutic management into practice requires an understanding of this concept. The outcomes of this study will enhance in-depth knowledge of the current status of Alzheimer's disease's diagnosis and treatment, justifying the necessity for the quest for potential novel biomarkers that can contribute to determining the stage of the disease, particularly in its earliest stages. Interestingly, latest clinical trial status on pharmacological agents, the nonpharmacological treatments such as behavior modification, exercise, and cognitive training as well as alternative approach on phytochemicals as neuroprotective agents have been covered in detailed.

In Silico Prediction of Potential Inhibitors for Targeting RNA CAG Repeats via Molecular Docking and Dynamics Simulation: A Drug Discovery Approach

Spinocerebellar ataxia (SCA) is a rare neurological illness inherited dominantly that causes severe impairment and premature mortality. While each rare disease may affect individuals infrequently, collectively they pose a significant healthcare challenge. It is mainly carried out due to the expansion of RNA triplet (CAG) repeats, although missense or point mutations can also be induced. Unfortunately, there is no cure; only symptomatic treatments are available. To date, SCA has about 48 subtypes, the most common of these being SCA 1, 2, 3, 6, 7, 12, and 17 having CAG repeats. Using molecular docking and molecular dynamics (MD) simulation, this study seeks to investigate effective natural herbal neuroprotective compounds against CAG repeats, which are therapeutically significant in treating SCA. Initially, virtual screening followed by molecular docking was used to estimate the binding affinity of neuroprotective natural compounds toward CAG repeats. The compound with the highest binding affinity, somniferine, was then chosen for MD simulation. The structural stability, interaction mechanism, and conformational dynamics of CAG repeats and somniferine were investigated via MD simulation. The MD study revealed that during the simulation period, the interaction between CAG repeats and somniferine stabilizes and results in fewer conformational variations. This in silico study suggests that Somniferine can be used as a therapeutic medication against RNA CAG repeats in SCA.

The Involvement of Antioxidants in Cognitive Decline and Neurodegeneration: Mens Sana in Corpore Sano

With neurodegenerative disorders being on the rise, a great deal of research from multiple fields is being conducted in order to further knowledge and propose novel therapeutic interventions. Among these investigations, research on the role of antioxidants in contrasting cognitive decline is putting forward interesting and promising results. In this review, we aim to collect evidence that focused on the role of a variety of antioxidants and antioxidant-rich foods in improving or stabilizing cognitive functions, memory, and Alzheimer's disease, the most common neurodegenerative disorder. Specifically, we considered evidence collected on humans, either through longitudinal studies or randomized, placebo-controlled ones, which evaluated cognitive performance, memory abilities, or the progression level of neurodegeneration. Overall, despite a great deal of variety between study protocols, cohorts of participants involved, neuropsychological tests used, and investigated antioxidants, there is a solid trend that suggests that the properties of antioxidants may be helpful in hampering cognitive decline in older people. Thus, the help of future research that will further elucidate the role of antioxidants in neuroprotection will lead to the development of novel interventions that will take into account such findings to provide a more global approach to treating neurodegenerative disorders.

Hypoglycemic, anti-inflammatory, and neuroprotective potentials of crude methanolic extract from Acacia nilotica L. - results of an in vitro study

Acacia nilotica L., also known as babul, belonging to the Fabaceae family and the Acacia genus, is typically used for ornamental purposes and also as a medicinal plant found in tropical and subtropical areas. This plant is a rich source of bioactive compounds. The current study aimed to elucidate the hypoglycemic, anti-inflammatory, and neuroprotective potential of A. nilotica's crude methanolic extract. The results of the in vitro antidiabetic assay revealed that methanolic extract of A. nilotica inhibited the enzyme α-glucosidase (IC50: 33 μg mL-1) and α-amylase (IC50: 17 μg mL-1) in a dose-dependent manner. While in the anticholinesterase enzyme inhibitory assay, maximum inhibition was shown by the extract against acetylcholinesterase (AChE) (637.01 μg mL-1) and butyrylcholinesterase (BChE) (491.98 μg mL-1), with the highest percent inhibition of 67.54% and 71.50% at 1000 μg mL-1, respectively. This inhibitory potential was lower as compared to the standard drug Galantamine that exhibited 82.43 and 89.50% inhibition at the same concentration, respectively. Moreover, the methanolic extract of A. nilotica also significantly inhibited the activities of cyclooxygenase 2 (COX-2) and 5-lipoxygenase (5-LOX) in a concentration-dependent manner. The percent inhibitory activity of 5-LOX and COX-2 ranged from 42.47% to 71.53% and 43.48% to 75.22%, respectively. Furthermore, in silico, in vivo, and clinical investigations must be planned to validate the above-stated bioactivities of A. nilotica.

ADME profiling, molecular docking, DFT, and MEP analysis reveal cissamaline, cissamanine, and cissamdine from Cissampelos capensis L.f. as potential anti-Alzheimer's agents

The current pharmacotherapies for Alzheimer's disease (AD) demonstrate limited efficacy and are associated with various side effects, highlighting the need for novel therapeutic agents. Natural products, particularly from medicinal plants, have emerged as a significant source of potential neuroprotective compounds. In this context, Cissampelos capensis L.f., renowned for its medicinal properties, has recently yielded three new proaporphine alkaloids; cissamaline, cissamanine, and cissamdine. Despite their promising bioactive profiles, the biological targets of these alkaloids in the context of AD have remained unexplored. This study undertakes a comprehensive in silico examination of the binding affinity and molecular interactions of these alkaloids with human protein targets implicated in AD. The drug likeness and ADME analyses indicate favorable pharmacokinetic profiles for these compounds, suggesting their potential efficacy in targeting the central nervous system. Molecular docking studies indicate that cissamaline, cissamanine, and cissamdine interact with key AD-associated proteins. These interactions are comparable to, or in some aspects slightly less potent than, those observed with established AD drugs, highlighting their potential as novel therapeutic agents for Alzheimer's disease. Crucially, Density Functional Theory (DFT) calculations offer deep insights into the electronic and energetic characteristics of these alkaloids. These calculations reveal distinct electronic properties, with differences in total energy, binding energy, HOMO-LUMO gaps, dipole moments, and electrophilicity indices. Such variations suggest unique reactivity profiles and molecular stability, pertinent to their pharmacological potential. Moreover, Molecular Electrostatic Potential (MEP) analyses provide visual representations of the electrostatic characteristics of these alkaloids. The analyses highlight areas prone to electrophilic and nucleophilic attacks, indicating their potential for specific biochemical interactions. This combination of DFT and MEP results elucidates the intricate electronic, energetic, and electrostatic properties of these compounds, underpinning their promise as AD therapeutic agents. The in silico findings of this study shed light on the promising potential of cissamaline, cissamanine, and cissamdine as agents for AD treatment. However, further in vitro and in vivo studies are necessary to validate these theoretical predictions and to understand the precise mechanisms through which these alkaloids may exert their therapeutic effects.

The memory ameliorating effects of novel N-benzyl pyridine-2-one derivatives on scopolamine-induced cognitive deficits in mice

BACKGROUND

Alzheimer's disease (AD), the most common form of progressive dementia in the elderly, is a chronic neurological disorder that decreases cognitive ability. Although the underlying cause of AD is yet unknown, oxidative stress and brain acetylcholine shortage are the key pathogenic causes.

RESULTS

The current study shows that these derivatives have the potential to improve memory in mice by inhibiting scopolamine-induced acetylcholinesterase activity, oxidative and nitrosative stress, and improving locomotor activity and muscle grip strength in the rota rod test. When compared to the illness control, the memory-enhancing potential of novel N-benzyl pyridine-2-one derivatives was highly significant (P < 0.0001).

CONCLUSIONS

The observed memory ameliorating effect of novel N-benzyl pyridine-2-one makes them as a a good choice for treatment of individuals with cognitive impairment.

Novel Substituted Pyrimidine Derivatives as Potential Anti-Alzheimer's Agents: Synthesis, Biological, and Molecular Docking Studies

The most frequent type of age-related dementia is Alzheimer's disease. To discover novel therapeutic agents for Alzheimer's disease, a series of substituted pyrimidine derivatives were synthesized and evaluated for anti-Alzheimer's activity. All the synthesized compounds were validated by 1HNMR, 13CNMR, and HRMS to assess the structural conformance of the newly synthesized compounds. The synthesized compounds were then evaluated for their in vivo acute toxicity study. Evaluation of acute toxicity showed that none of the synthesized compounds showed toxicity up to 1000 mg/kg. After in vivo acute toxicity studies, the compounds were subjected to behavioral and biochemical studies. Compound N4-(4-chlorophenyl)-N2-(2-(piperidin-1-yl)ethyl)pyrimidine-2,4-diamine 5b (SP-2) displayed an excellent anti-Alzheimer's profile, while the rest of the compounds showed satisfactory results in comparison to donepezil. Docking studies confirmed the results obtained through in vivo experiments and showed that 5b (SP-2) showed a similar interaction to that of donepezil. Further, in silico molecular property predictions showed that 5b (SP-2) possesses favorable drug-likeness and ADME properties for CNS activity. These results implied that 5b could serve as an appropriate lead molecule for the development of anti-Alzheimer's agent.

The Meaning of Plants' Names: A New Discovering Approach to Its Medicinal and/or Toxic Properties

Some of the vernacular or scientific names are related to possible medicinal and/or toxic properties that can reveal the presence of potential bioactive agents, contributing to the discovery of new drugs and/or knowledge of the risks associated with their use. This study sought to list the scientific and vernacular names of plants whose lexicons are related to those possible properties of plants and to compare them with the "ethno" (ethnobotanical and ethnopharmacological) and pharmacological data available in the scientific literature. A floating reading of the two classical and reference works on Brazilian medicinal plants was performed, and plants with vernacular and/or scientific names related to the possible medicinal and/or toxic properties were listed. Correlations between the meanings of the species' names (lexicon) and their possible biological properties were made from their translation from Latin by consulting dictionaries. A bibliographic survey was conducted on the "ethno" and pharmacological data for each species. Finally, data from these three dimensions (lexicon, "ethno," and pharmacology) were classified and compared using a bioprospection classification. It resulted in a list of 90 plant species belonging to 47 families. 66 of the 90 species presented "ethno" data from the scientific literature, while 46 species presented pharmacological data. Of these, 46 (69.7%) and 27 (58.7%), respectively, showed equivalence with the possible medicinal and/or toxic properties of plants according to their lexicons. According to this study, half of the plants investigated demonstrate equivalence in the three dimensions analyzed (lexicons, "ethno," and pharmacological data from the scientific literature). Gastrointestinal and nervous system categories are among the most common in all three dimensions. Plant lexicons may be closely linked to the possible medicinal and/or toxic properties and the study of plant lexicons may represent one more approach for the search for new drugs, mainly considering the gastrointestinal, nervous, and parasites categories.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

Neuroinflammatory Response and Redox-regulation Activity of Hyperoside in Manganese-induced Neurotoxicity Model of Wistar Rats

BACKGROUND

Excessive manganese exposure can lead to neurotoxicity with detrimental effects on the brain. Neuroinflammatory responses and redox regulation play pivotal roles in this process. Exploring the impact of hyperoside in a Wistar rat model offers insights into potential neuroprotective strategies against manganese-induced neurotoxicity.

OBJECTIVE

The study investigated the neuroprotective efficacy of hyperoside isolated from the ethanol leaf extract of Gongronema latifolium (HELEGL), in the brain tissue of Wistar rats following 15 consecutive days of exposure to 30 mg/L of MnCl2.

METHODS

Control animals in Group 1 had access to regular drinking water, while animals in groups 2-4 were exposed to MnCl2 in their drinking water. Groups 3 and 4 also received additional HELEGL at doses of 100 mg/kg and 200 mg/kg of body weight, respectively. In Group 5, HELEGL at a dose of 100 mg/kg of body weight was administered alone. Treatment with HELEGL commenced on day 8 via oral administration.

RESULTS

HELEGL effectively mitigated MnCl2-induced memory impairment, organ-body weight discrepancies, and fluid intake deficits. Exposure to MnCl2 increased the activities or levels of various markers such as acyl peptide hydrolase, tumour necrosis factor-α, dipeptidyl peptidase IV, nitric oxide, IL-1β, prolyl oligopeptidase, caspase-3, myeloperoxidase, H2O2, and malondialdehyde, while it decreased the activities or levels of others, including AChE, BChE, DOPA, serotonin, epinephrine, norepinephrine, GST, GPx, CAT, SOD, GSH, and T-SH (p < 0.05). In contrast, HELEGL effectively counteracted the adverse effects of MnCl2 by alleviating oxidative stress, inflammation, apoptosis, mitochondrial dysfunction, cognitive deficits, and bolstering the antioxidant status. Moreover, HELEGL restored the normal histoarchitecture of the brain, which had been distorted by MnCl2.

CONCLUSION

In summary, HELEGL reversed the causative factors of neurodegenerative diseases induced by MnCl2 exposure, suggesting its potential for further exploration as a prospective therapeutic agent in the management of Alzheimer's disease and related forms of dementia.

The effect of light therapy on sleep disorders and psychobehavioral symptoms in patients with Alzheimer's disease: A meta-analysis

BACKGROUND

Although Alzheimer's disease (AD) mainly affects cognitive function, it is often accompanied by sleep disorders and psychobehavioral symptoms. These symptoms, including depression, agitation, and psychotic symptoms, are prominent hospitalization causes among patients with AD. Currently, relatively more research exists on light therapy for sleep disorders, while those on psychobehavioral symptoms are gradually increasing. However, no consensus exists on these results because of the vulnerability of light therapy to multiple factors, including light intensity and duration. Thus, further research investigating this aspect is warranted.

OBJECTIVE

To evaluate the efficacy of light therapy in improving sleep disorders and psychobehavioural symptoms in patients with AD.

METHODS

In this meta-analysis, relevant literature was searched in Embase, the Clinical Trials Registry, Web of Science, PubMed, and the Cochrane Library up to December 2022. Furthermore, a fixed-effects model was used for data analysis.

RESULTS

Fifteen randomized controlled trials involving 598 patients with AD were included. In the case of sleep disorders, our meta-analysis revealed that light therapy significantly improved sleep efficiency (MD = -2.42, 95% CI = -3.37 to -1.48, p < 0.00001), increased interdaily stability (MD = -0.04, 95% CI = -0.05 to -0.03, p < 0.00001), and reduced intradaily variability (MD = -0.07, 95% CI = -0.10 to -0.05, p < 0.00001). With respect to psychotic behavior, light therapy was found to alleviate depression (MD = -2.55, 95% CI = -2.98 to -2.12, p < 0.00001) as well as reduce agitation (MD = -3.97, 95% CI = -5.09 to -2.84, p < 0.00001) and caregiver burden (MD = -3.57, 95% CI = -5.28 to -1.87, p < 0.00001).

CONCLUSION

Light therapy leads to significant improvement in sleep and psychobehavioral symptoms and is associated with relatively fewer side effects in patients with AD, indicating its potential as a promising treatment option for AD.

Voxel Extraction and Multiclass Classification of Identified Brain Regions across Various Stages of Alzheimer's Disease Using Machine Learning Approaches

This study sought to investigate how different brain regions are affected by Alzheimer's disease (AD) at various phases of the disease, using independent component analysis (ICA). The study examines six regions in the mild cognitive impairment (MCI) stage, four in the early stage of Alzheimer's disease (AD), six in the moderate stage, and six in the severe stage. The precuneus, cuneus, middle frontal gyri, calcarine cortex, superior medial frontal gyri, and superior frontal gyri were the areas impacted at all phases. A general linear model (GLM) is used to extract the voxels of the previously mentioned regions. The resting fMRI data for 18 AD patients who had advanced from MCI to stage 3 of the disease were obtained from the ADNI public source database. The subjects include eight women and ten men. The voxel dataset is used to train and test ten machine learning algorithms to categorize the MCI, mild, moderate, and severe stages of Alzheimer's disease. The accuracy, recall, precision, and F1 score were used as conventional scoring measures to evaluate the classification outcomes. AdaBoost fared better than the other algorithms and obtained a phenomenal accuracy of 98.61%, precision of 99.00%, and recall and F1 scores of 98.00% each.

Dopaminergic modulation by quercetin: In silico and in vivo evidence using Caenorhabditis elegans as a model

Quercetin is a flavonol widely distributed in plants and has various described biological functions. Several studies have reported on its ability to restore neuronal function in a wide variety of disease models, including animal models of neurodegenerative disorders such as Parkinson's disease. Quercetin per se can act as a neuroprotector/neuromodulator, especially in diseases related to impaired dopaminergic neurotransmission. However, little is known about how quercetin interacts with the dopaminergic machinery. Here we employed the nematode Caenorhabditis elegans to study this putative interaction. After observing behavioral modulation, mutant analysis and gene expression in C. elegans upon exposure to quercetin at a concentration that does not protect against MPTP, we constructed a homology-based dopamine transporter protein model to conduct a docking study. This led to suggestive evidence on how quercetin may act as a dopaminergic modulator by interacting with C. elegans' dopamine transporter and alter the nematode's exploratory behavior. Consistent with this model, quercetin controls C. elegans behavior in a way dependent on the presence of both the dopamine transporter (dat-1), which is up-regulated upon quercetin exposure, and the dopamine receptor 2 (dop-2), which appears to be mandatory for dat-1 up-regulation. Our data propose an interaction with the dopaminergic machinery that may help to establish the effects of quercetin as a neuromodulator.

Scaling the Andean Shilajit: A Novel Neuroprotective Agent for Alzheimer's Disease

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder without a cure, despite the enormous number of investigations and therapeutic approaches. AD is a consequence of microglial responses to "damage signals", such as aggregated tau oligomers, which trigger a neuro-inflammatory reaction, promoting the misfolding of cytoskeleton structure. Since AD is the most prevalent cause of dementia in the elderly (>60 years old), new treatments are essential to improve the well-being of affected subjects. The pharmaceutical industry has not developed new drugs with efficacy for controlling AD. In this context, major attention has been given to nutraceuticals and novel bioactive compounds, such as molecules from the Andean Shilajit (AnSh), obtained from the Andes of Chile. Primary cultures of rat hippocampal neurons and mouse neuroblastoma cells were evaluated to examine the functional and neuroprotective role of different AnSh fractions. Our findings show that AnSh fractions increase the number and length of neuronal processes at a differential dose. All fractions were viable in neurons. The AnSh fractions inhibit tau self-aggregation after 10 days of treatment. Finally, we identified two candidate molecules in M3 fractions assayed by UPLC/MS. Our research points to a novel AnSh-derived fraction that is helpful in AD. Intensive work toward elucidation of the molecular mechanisms is being carried out. AnSh is an alternative for AD treatment or as a coadjuvant for an effective treatment.

Lycopene destabilizes preformed Aβ fibrils: Mechanistic insights from all-atom molecular dynamics simulation

The therapeutic strategy employing destabilization of the preformed Aβ fibril by various natural compounds, as studied by experimental and computational methods, has been reported significant in curing Alzheimer's disease (AD). However, lycopene (a carotenoid), from terpenes family, needs investigation for its destabilization potential of Aβ fibril. The highest antioxidant potential and ability to cross blood brain barrier makes lycopene a preferred choice as drug lead for treating AD. The current study focuses on investigating the destabilization potential and underpinning mechanism of lycopene on different polymorphic forms of Aβ fibril via Molecular Dynamics (MD) simulation. The key findings highlight binding of lycopene to the outer surface of the chain F of the fibril (2NAO). Herein G9, K16 and V18 residues were found to be involved in van der Waals with the methyl groups of the lycopene. Additionally, Y10 and F20 residues were observed to interact via π-π interactions with CC bonds of the lycopene. The surface mediated binding of lycopene to the fibril is attributed to the large size and structural rigidity of lycopene along with the bulky size of 2NAO and narrow space of fibrillar cavity. The destabilization of the fibril is evident by breakage of inherent H-bonds and hydrophobic interactions in the presence of one lycopene molecule. The lesser β-sheet content explains disorganization of the fibril and bars the higher order aggregation curbing neurotoxicity of the fibril. The higher concentration of the lycopene is not found to be linearly correlated with the extent of destabilization of the fibril. Lycopene is also observed to destabilize the other polymorphic form of Aβ fibril (2BEG), by accessing the fibrillar cavity and lowering the β-sheet content. The destabilization observed by lycopene on two major polymorphs of Aβ fibril explains its potency towards developing an effective therapeutic approach in treating AD.

Natural products derived steroids as potential anti-leishmanial agents; disease prevalence, underlying mechanisms and future perspectives

Leishmaniasis is a vector-borne infection caused by protozoan parasites from the genus leishmania and is among the most neglected tropical diseases. It is highly prevalent disease, affecting about 350 million population worldwide. Only limited number of anti-leishmanial agents are approved for clinical use till now and they are associated with side effects and have limited efficacy. Subsequently, natural products based discovery of more safe and effective drugs against leishmania is under scientific consideration. Various studies reported the efficacy of natural products against intracellular and extracellular forms of leishmania species. This work is aimed to evaluate current literature focused on the anti-leihmanial efficacy of steroidal moieties from natural products and their mechanism of action. Compounds including steroidal saponins, steroidal alkaloids and phytosterols were found to exhibit considerable anti-leishmanial efficacy. For instance, steroidal saponin, (25R)-spirost-5-en-3b-ol,3-O-α-rhamnopyranosyl-(1 → 4)-α-rhamnopyranosyl-(1 → 4)-[a-rhamnopyranosyl-(1 → 2)]-glucopyranoside isolated from A. paradoxum has completely eradicated Leishmania major promastigotes at 50 µg mL-1 dose. Spirostanic saponins isolated from Solanum paniculatum L. were effective against Leishmania amazonensis promastigotes. Turgidosterones isolated from Panicum turgidum exhibited high leishmanicidal potentials against Leishmania donovani promastigotes with IC50 of 4.95-8.03 µg mL-1 and even better activity against amastigotes exhibiting an IC50 of 4.50-9.29 µg mL-1. Likewise, racemoside-A from Asparagus racemosus was found effective against an antimonial sensitive (AG83) and antimonial resistant (GE1F8R) strains of the L. donovani. Moreover, steroidal alkaloids including hookerianamide-1, hookerianamide-H, hookerianamide-J, hookerianamide-K, dehydrosarsalignone, vagenine-A, sarcovagine-C, holaphylline, saracodine, holamine, 15-α hydroxyholamine, holacurtin, N-desmethyl holacurtine and elasticine has exhibited time and dose-dependent efficacy against various strains of leishmania. β-sitosterol was found active against multiple strains of leishmania. These compounds mainly exhibit their therapeutic efficacy via liberation of ROS, mitochondrial depolarization, morphological and ultra-structural changes, accumulation of lipid droplets, depletion of non-protein thiols and triggering apoptotic pathways. In conclusion, leishmaniasis is a major health problem in many countries. Plants-derived steroids moieties have reveled efficacy against leishmaniasis and is a source of lead compounds. Further detailed molecular studies are warranted for the discovery of more effective and safe anti-leishmanial drugs.

Therapeutic and medicinal effects of snowdrop (Galanthus spp.) in Alzheimer's disease: A review

Genus Galanthus (Amaryllidaceae) is an early spring flowering bulbous plant. Galanthus species contain alkaloids that have shown pharmacological activity. Galanthamine is an alkaloid that was extracted from Galanthus and other Amaryllidaceae. Owing to its acetylcholinesterase (AChE) inhibitory activity, galanthamine is used and marketed to treat Alzheimer's disease (AD). The aim of the present study, while introducing the botanical and pharmacological characteristics and various aspects of the medicinal plant Galanthus, is to emphasize the effect of this plant in the treatment of AD. In this web-based study in 2021, articles indexed in scientific databases in English language, including ISI Web of Knowledge, PubMed, Scopus, MedLib, Medknow, SID, ISC, and also articles and e-books published in Springer, Elsevier, John Wiley and Sons, and Taylor and Francis were evaluated from 1990 to 2021, using the following keywords: "Galanthus" "galanthamine," "Alzheimer's disease." Amaryllidaceae-type alkaloids possess an anticholinesterase activity. The most studied Galanthus alkaloid, galanthamine, is a long-acting, selective, reversible, competitive inhibitor of AChE and an allosteric modulator of the neuronal nicotinic receptor for acetylcholine (ACh). Owing to its AChE inhibitory activity, galanthamine is used to treat certain stages of AD. Galantamine can act as a parasympathomimetic agent, especially as a reversible cholinesterase inhibitor. Galantamine is not structurally associated with other AChE inhibitors. Hence, its proposed mechanism of action involves the reversible inhibition of AChE, preventing hydrolysis of ACh that results in an increased concentration of ACh at cholinergic synapses.

QSAR, simulation techniques, and ADMET/pharmacokinetics assessment of a set of compounds that target MAO-B as anti-Alzheimer agent

Background

Alzheimer’s disease (AD), the most common cause of dementia in the elderly, is a progressive neurodegenerative disorder that gradually affects cognitive function and eventually causes death. Most approved drugs can only treat the disease alleviating the disease symptoms; therefore, there is a need to develop drugs that can treat this illness holistically. The medical community is searching for new drugs and new drug targets to cure this disease. In this study, QSAR, molecular docking evaluation, and ADMET/pharmacokinetics assessment were used as modeling methods to identify the compounds with outstanding physicochemical properties.

Results

The 37 MAO-B compounds were screened using the aforementioned methods and yielded a model with the following molecular properties: AATS1v, AATS3v, GATS4m, and GATS6e. Good statistical values were R2train = 0.69, R2adj = 0.63, R2pred = 0.57, LOF = 0.23, and RMSE = 0.38. The model was validated using an evaluation set that confirmed its robustness. The molecular docking was also utilized using crystal structure of human monoamine oxidase B in complex with chlorophenylchromone-carboxamide with ID code of 6FW0, and three compounds were identified with outstanding high binding affinity (13 = − 30.51 kcal mol−1, 31 = − 31.85 kcal mol−1, and 33 = − 33.70 kcal mol−1), and better than the Eldepryl (referenced) drug (− 11.40 kcal mol−1).

Conclusions

These three compounds (13, 31, and 33) were analyzed for ADMET/pharmacokinetics evaluation and found worthy of further analysis as promising drug candidates to cure AD and could also serve as a template to design several monoamine oxidase B inhibitors in the future to cure AD.

Evaluation of Mollugo oppositifolia Linn. as cholinesterase and β-secretase enzymes inhibitor

Mollugo oppositifolia Linn. is traditionally used in neurological complications. The study aimed to investigate in-vitro neuroprotective effect of the plant extracts through testing against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase linked to Alzheimer's disease (AD). To understand the safety aspects, the extracts were tested for CYP450 isozymes and human hepatocellular carcinoma cell (HepG2) inhibitory potential. The heavy metal contents were estimated using atomic absorption spectroscopy (AAS). Further, the antioxidant capacities as well as total phenolic content and total flavonoid content (TFC) were measured spectrophotometrically. UPLC-QTOF-MS/MS analysis was employed to identify phytometabolites present in the extract. The interactions of the ligands with the target proteins (AChE, BChE, and BACE-1) were studied using AutoDockTools 1.5.6. The results showed that M. oppositifolia extract has more selectivity towards BChE (IC₅₀ = 278.23 ± 1.89 μg/ml) as compared to AChE (IC₅₀ = 322.87 ± 2.05 μg/ml). The IC₅₀ value against β-secretase was 173.93 μg/ml. The extract showed a CC₅₀ value of 965.45 ± 3.07 μg/ml against HepG2 cells and the AAS analysis showed traces of lead 0.02 ± 0.001 which was found to be within the WHO prescribed limits. Moreover, the IC₅₀ values against CYP3A4 (477.03 ± 2.01 μg/ml) and CYP2D6 (249.65 ± 2.46 μg/ml) isozymes justify the safety aspects of the extract. The in silico molecular docking analysis of the target enzymes showed that the compound menthoside was found to be the most stable and showed a good docking score among all the identified metabolites. Keeping in mind the multi-targeted drug approach, the present findings suggested that M. oppositifolia extract have anti-Alzheimer's potential.

Neuroprotective Effect of Quercetin and Memantine against AlCl3-Induced Neurotoxicity in Albino Wistar Rats

Recent evidences indicate that there is a substantial increase in worldwide cases of dementia. Alzheimer's disease is the leading cause of dementia and may contribute to 60-70% of cases. Quercetin is a unique bioflavonoid that has numerous therapeutic benefits such as anti-allergy, anti-ulcer, anti-inflammatory, anti-hypertensive, anti-cancer, immuno-modulatory, anti-infective, antioxidant, acetylcholinesterase inhibitory activity, neuroprotective effects, etc. In the present study, we evaluated the neuroprotective effect of orally administered quercetin with memantine in albino Wistar rats after inducing neurotoxicity through AlCl3 (100 mg/kg, p.o.). Chronic administration of AlCl3 resulted in poor retention of memory and significant oxidative damage. Various behavioral parameters, such as locomotor activity, Morris water maze, elevated plus maze, and passive avoidance test, were assessed on days 21 and 42 of the study. The animals were euthanatized following the completion of the last behavioral assessment. Various oxidative stress parameters were assessed to know the extent of oxidative damage to brain tissue. Quercetin with memantine has shown significant improvement in behavioral studies, inhibition of AChE activity, and reduction in oxidative stress parameters. Histopathological studies assessed for cortex and hippocampus using hematoxylin and eosin (H&E), and Congo red stain demonstrated a reduction in amyloid-β plaque formation after treatment of quercetin with memantine. Immunohistochemistry showed that quercetin with memantine treatment also improved the expression of brain-derived neurotrophic factor (BDNF) and inhibited amyloid-β plaque formation. The present study results demonstrated protective effects of treatment of quercetin with memantine in the neurotoxicity linked to aluminum chloride in albino Wistar rats.

In-silico evaluations of the isolated phytosterols from polygonum hydropiper L against BACE1 and MAO drug targets

Our previous anti-Alzheimer's studies on crude extracts, essential oils and isolated compounds including β-sitostrol from Polygonum hydropiper L, motivated us for further studies against beta amyloid cleaving enzyme 1 (BACE1) and monoamine oxidases (MAO-A), (MAO-B) enzymes. Before performing detailed studies on the compounds using animal models and immunohistochemistry, molecular docking study was performed against three vital enzymes implicated in several neurological disorders including Alzheimer's disease (AD), Parkinson's disease (PD), depression and anxiety to predict their inhibitory potential against important enzymes. Beta amyloid cleaving enzyme 1 (BACE1) is important enzyme that catalyze pathological amyloidogenic pathway of processing amyloid precursor proteins to form neurotoxic amyloid plaques. Subsequently, BACE1 inhibitors are considered an important tool in the management of AD. MAOs have been categorized in two well-known groups MAO-A and MAO-B, based on their differential affinity for various monoamines substrates. MAO-A has more affinity for norepinephrine and 5-HT, whereas, MAO-B mainly catalyze the breakdown of dopamine and 2-phenylathylamine (PEA) and other monoamines. Subsequently, they have divergent behavioral outcomes and play a significant role in pathophysiology of several neurodegenerative disorders like AD, depression, drug abuse, migraines, schizophrenia, Attention Deficit Disorder (ADD) and Parkinson's disease (PD). Molecular docking was carried out to predict the binding modes of β-sitosterol and stigmasterol in the binding pockets of BACE1 (beta-sectretase 1) and MAO (monoamine oxidase A, B) enzymes. The 3 D structure of BACE1 (PDB ID: 2QP8), MAO A (PDB ID: 2ZPX) and MAO B (PDB ID: 2XFN) were downloaded from protein databank. The 3 D structures were then subjected to protonation and energy minimization using default parameters of MOE. Three dimensional structures of β-sitosterol and stigmasterol were built by using Molecular Builder Module program implemented in MOE and saved as a (.mdb) file for molecular docking. Subsequently, the energy of both the compounds were minimized up to 0.05 Gradient using MMFF 94 s force field implemented in MOE. Both the compounds were docked into the active site of proteins using the Triangular Matching docking method (default) and 10 different conformations for each compound were generated. To obtain minimum energy structures the ligands were allowed to be flexible during docking. At the end of docking, the predicted ligand-protein complexes were analyzed for molecular interactions. Overall the docking results showed that these compounds showed good interaction with active site residues of BACE1 as compare to MAO-A and MAO-B. Furthermore, β-sitosterol showed good interaction with BACE1 as compare to stigmasterol.Communicated by Ramaswamy H. Sarma.

In-Vitro, In-Vivo, Molecular Docking and ADMET Studies of 2-Substituted 3,7-Dihydroxy-4H-chromen-4-one for Oxidative Stress, Inflammation and Alzheimer's Disease

Plants' bioactives are well-known safe drugs for vital diseases. Flavones and Flavonoid-rich dietary supplements are known to exhibit neuroprotective potential. In this study, we isolated a flavone 2-(3,4-dimethoxyphenyl)-3,7-dihydroxy-4H-chromen-4-one from Notholirion thomsonianum and it was evaluated against various targets of the oxidative stress-related neurological disorders. The compound showed excellent acetyl and butyrylcholinesterase inhibitions in its profile, giving IC50 values of 1.37 and 0.95 μM, respectively. Similarly, in in-vitro MAO-B assay, our flavone exhibited an IC50 value of 0.14 μM in comparison to the standard safinamide (IC50 0.025 μM). In in-vitro anti-inflammatory assay, our isolated compound exhibited IC50 values of 7.09, 0.38 and 0.84 μM against COX-1, COX-2 and 5-LOX, respectively. The COX-2 selectivity (SI) of the compound was 18.70. The compound was found safe in animals and was very effective in carrageenan-induced inflammation. Due to the polar groups in the structure, a very excellent antioxidant profile was observed in both in-vitro and in-vivo models. The compound was docked into the target proteins of the respective activities and the binding energies confirmed the potency of our compound. Furthermore, absorption, distribution, metabolism, excretion, and toxicity (ADMET) results showed that the isolated flavone has a good GIT absorption ability and comes with no hepatic and cardiotoxicity. In addition, the skin sensitization test, in-vitro human cell line activation test (h-CLAT) and KeratinoSens have revealed that isolated flavone is not skin sensitive with a confidence score of 59.6% and 91.6%. Herein, we have isolated a natural flavone with an effective profile against Alzheimer's, inflammation and oxidative stress. The exploration of this natural flavone will provide a baseline for future research in the field of drug development.

Efficacy of Rytigynia senegalensis Blume on Free Radical Scavenging, Inhibition of α-Amylase and α-Glucosidase Activity, and Blood Glucose Level

Rytigynia senegalensis (Rubiaceae) is a plant used in African medicine for the treatment of diabetes. The aim of this study was to evaluate the in vitro antioxidant, enzyme inhibitory, and hypoglycemic effects of Rytigynia senegalensis extract (RSE). The contents of phenols, tannins, and flavonoids were determined by phytochemical screening. 2,2-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenylpicrylhydrazyl (DPPH) were determined to evaluate the free radical scavenging capacity of the RSE. The inhibitory activity of α-amylase and α-glucosidase was evaluated in vitro using the α-amylase and α-glucosidase inhibition methods and in vivo using the sucrose and starch tolerance tests. The glucose tolerance test was performed on normal rats using doses of 50, 100, and 200 mg/kg of RSE. RSE contains total phenols (36.35 mg GAE/g of extract), flavonoids (11.91 mg QE/g of extract), and tannins (13.01 mg CE/g of extract). RSE exhibits significant radical scavenging activity on DPPH and ABTS radicals with an IC₅₀ of 17.51 and 21.89 μg/mL, respectively. RSE showed an inhibitory effect on the activity of α-amylase and α-glucosidase with an IC₅₀ of 308.93 and 354.13 μg/mL, respectively. RSE (100 and 200 mg/kg) caused a significant decrease in area under the curve and postprandial glycemia at 60, 90, and 120 min following the administration of starch or sucrose. Regarding the glucose tolerance test, RSE (100 and 200 mg/kg) significantly reduced postprandial hyperglycemia from the 90th min posttreatment. RSE lowered postprandial hyperglycemia and has antioxidant properties. These effects would be due to the presence of bioactive compounds in the RSE.

Multi-Target Mechanisms of Phytochemicals in Alzheimer’s Disease: Effects on Oxidative Stress, Neuroinflammation and Protein Aggregation

Alzheimer’s disease (AD) is a neurodegenerative disease characterized by a tangle-shaped accumulation of beta-amyloid peptide fragments and Tau protein in brain neurons. The pathophysiological mechanism involves the presence of Aβ-amyloid peptide, Tau protein, oxidative stress, and an exacerbated neuro-inflammatory response. This review aims to offer an updated compendium of the most recent and promising advances in AD treatment through the administration of phytochemicals. The literature survey was carried out by electronic search in the following specialized databases PubMed/Medline, Embase, TRIP database, Google Scholar, Wiley, and Web of Science regarding published works that included molecular mechanisms and signaling pathways targeted by phytochemicals in various experimental models of Alzheimer’s disease in vitro and in vivo. The results of the studies showed that the use of phytochemicals against AD has gained relevance due to their antioxidant, anti-neuroinflammatory, anti-amyloid, and anti-hyperphosphorylation properties of Tau protein. Some bioactive compounds from plants have been shown to have the ability to prevent and stop the progression of Alzheimer’s.

Therapeutic insights elaborating the potential of retinoids in Alzheimer’s disease

Alzheimer’s disease (AD) is perceived with various pathophysiological characteristics such oxidative stress, senile plaques, neuroinflammation, altered neurotransmission immunological changes, neurodegenerative pathways, and age-linked alterations. A great deal of studies even now are carried out for comprehensive understanding of pathological processes of AD, though many agents are in clinical trials for the treatment of AD. Retinoids and retinoic acid receptors (RARs) are pertinent to such attributes of the disease. Retinoids support the proper functioning of the immunological pathways, and are very potent immunomodulators. The nervous system relies heavily on retinoic acid signaling. The disruption of retinoid signaling relates to several pathogenic mechanisms in the normal brain. Retinoids play critical functions in the neuronal organization, differentiation, and axonal growth in the normal functioning of the brain. Disturbed retinoic acid signaling causes inflammatory responses, mitochondrial impairment, oxidative stress, and neurodegeneration, leading to Alzheimer’s disease (AD) progression. Retinoids interfere with the production and release of neuroinflammatory chemokines and cytokines which are located to be activated in the pathogenesis of AD. Also, stimulating nuclear retinoid receptors reduces amyloid aggregation, lowers neurodegeneration, and thus restricts Alzheimer’s disease progression in preclinical studies. We outlined the physiology of retinoids in this review, focusing on their possible neuroprotective actions, which will aid in elucidating the critical function of such receptors in AD pathogenesis.

Succinimide Derivatives as Antioxidant Anticholinesterases, Anti-α-Amylase, and Anti-α-Glucosidase: In Vitro and In Silico Approaches

Based on the diverse pharmacological potency and the structural features of succinimide, this research considered to synthesize succinimide derivatives. Moreover, these compounds were estimated for their biological potential in terms of anti-diabetic, anti-cholinesterase, and anti-oxidant capacities. The compounds were synthesized through Michael addition of various ketones to N-aryl maleimides. Similarly, the MOE software was used for the molecular docking study to explore the binding mode of the potent compounds against different enzymes. In the anti-cholinesterase activity, the compounds MSJ2 and MSJ10 exhibited outstanding activity against acetylcholinesterase (AChE), i.e., 91.90, 93.20%, and against butyrylcholinesterase (BChE), i.e., 97.30, 91.36% inhibitory potentials, respectively. The compounds MSJ9 and MSJ10 exhibited prominent α-glucosidase inhibitory potentials, i.e., 87.63 and 89.37 with IC₅₀ value of 32 and 28.04 μM, respectively. Moreover, the compounds MSJ2 and MSJ10 revealed significant scavenging activity against DPPH free radicals with IC₅₀ values of 2.59 and 2.52, while against ABTS displayed excellent scavenging potential with IC₅₀ values 7.32 and 3.29 μM, respectively. The tentative results are added with molecular docking studies in the active sites of enzymes to predict the theoretical protein-ligand binding modes. Further detailed mechanism-based studies in animal models are essential for the in vivo evaluation of the potent compound.

Development of potent cholinesterase inhibitors based on a marine pharmacophore

The management of neurological disorders such as dementia associated with Alzheimer's or Parkinson's disease includes the use of cholinesterase inhibitors. These compounds can slow down the progression of these diseases and can also be used in the treatment of glaucoma and myasthenia gravis. The majority of the cholinesterase inhibitors used in the clinic are derived from natural products and our current paper describes the use of a small marine pharmacophore to develop potent and selective cholinesterase inhibitors. Fourteen small inhibitors were designed based on recent discoveries about the inhibitory potential of a range of related marine secondary metabolites. The compounds were evaluated, in kinetic enzymatic assays, for their ability to inhibit three different cholinesterase enzymes and it was shown that compounds with a high inhibitory activity towards electric eel and human recombinant acetylcholinesterase (IC₅₀ between 20-70 μM) could be prepared. It was also shown that this compound class was particularly active against horse serum butyrylcholinesterase, with IC₅₀ values between 0.8-16 μM, which is an order of magnitude more potent than the clinically used positive control neostigmine. The compounds were further tested for off-target toxicity against both human umbilical vein endothelial cells and bovine and human erythrocytes and were shown to display a low mammalian cellular toxicity. Overall, the study illustrates how the brominated dipeptide marine pharmacophore can be used as a versatile natural scaffold for the design of potent, and selective cholinesterase inhibitors.

Design, synthesis and evaluation of 2-(2-oxoethyl)pyrimidine-5-carboxamide derivatives as acetylcholinesterase inhibitors

A novel series of 2-(2- oxoethyl)pyrimidine-5-carboxamide derivatives were designed, synthesized and evaluated as acetylcholinesterase inhibitors (AChEIs) for the treatment of Alzheimer's disease (AD). Biological activity results demonstrated that compound 10q showed the best inhibitory activity against AChE (IC₅₀=0.88±0.78 μM), which was better than that of Huperzine-A, and its inhibitory effect on BuChE was weak (IC₅₀=10.0±1.30 μM), which indicated that compound 10q was a dominant AChE inhibitor. In addition, the result of molecular docking study displayed that 10q could simultaneously bind to CAS and PAS sites of AChE, which was consistent with the mixed inhibition mode shown by the enzymatic kinetics study of 10q. Furthermore, the molecular properties of the target compounds were predicted online using the molinspiration server and pkCSM , The results exhibited that compound 10q had drug-like properties that satisfied the Lipinski's rule of five. Based on the bioactivity and molecular properties, compound 10q for further development was valuable.

Rivea hypocrateriformis (Desr.) Choisy: An Overview of Its Ethnomedicinal Uses, Phytochemistry, and Biological Activities and Prospective Research Directions

Rivea hypocrateriformis (Desr.) Choisy is a robust woody climbing shrub of the genus Rivea which is widely distributed in India, Nepal, Sri Lanka, Pakistan, Bangladesh, Myanmar, and Thailand. R. hypocrateriformis is a promising medicinal herb with a wide range of beneficial and health-promoting properties. Since the ancient times, it has been used as a traditional medicine to treat rheumatic pain, fever, urogenital problems, snake bites, cough, piles, malaria, and skin diseases. Aside from these traditional uses, its leaves and young shoots are also cooked and eaten as a vegetable and used for the preparation of bread with millet flour. This study extensively analyzes the available information on R. hypocrateriformis botanical characterization, distribution, traditional applications, phytochemistry, pharmacology, and toxicological properties. Phytochemical investigations of the plant has revealed the presence of highly valuable secondary metabolites including alkaloids, glycosides, coumarins, flavonoids, xanthones, stilbenes, and other organic compounds. Its crude extracts and isolated compounds have revealed anovulatory, antifertility, antiarthritic, antimicrobial, anticancer, antioxidant hepatoprotective, antilithiatic, and antimitotic potentials. This review of literature clearly identifies R. hypocrateriformis as a potent medicinal plant with remarkable healing and health-promoting properties. Further research directions into the bioactive extracts, clinical, and toxicological evaluations to assess the beneficial health-promoting properties of this promising herb are also discussed.

Comparative in-vitro anti-inflammatory, anticholinesterase and antidiabetic evaluation: computational and kinetic assessment of succinimides cyano-acetate derivatives

This research was planned to synthesize cyano-acetate derivatives of succinimide and evaluate its comparative biological efficacy as anti-inflammatory, anti-cholinesterase and anti-diabetic, which was further validated by molecular docking studies. The three cyano-acetate derivatives of succinimide including compound 23 Methyl 2-cyano-2-(2,5-dioxopyrrolidin-3-yl)acetate, compound 31 Methyl 2-cyano-2-(1-methyl-2,5-dioxopyrrolidin-3-yl)acetate and compound 44 Methyl 2-cyano-2-(1-ethyl-2,5-dioxopyrrolidin-3-yl) acetate were synthesized. The mentioned compounds were checked for in vitro anti-inflammatory, anti-cholinesterase and anti-diabetic (α-amylase inhibition) activity. To validate the in vitro results, computational studies were carried out using molecular operating environment to analyse the BE, i.e. binding energies of all synthesized compounds against the respective enzymes. The Compounds 23, 31, 44 exhibited anti-inflammatory via inhibiting COX-2 (IC50 value of 204.08, 68.60 and 50.93 µM, respectively), COX-1 (IC50 value of 287, 185, and 143 µM, respectively) and 5-LOX (IC50 value of 138, 50.76 and 20, 87 µM respectively). They exhibited choline-mimetic potential, such as compound 23, 31 and 44 inhibited AChE enzyme (IC50 value of 240, 174, and 134 µM, respectively) and BChE enzyme (IC50 value of 203, 134 and 97 µM, respectively). The Compounds 23, 31, 44 exhibited anti-diabetic effect via inhibiting α-amylase enzyme (IC50 values of 250, 106 and 60 µM, respectively). Molecular docking studies revealed that the synthesized compounds have good binding affinity in the binding pockets of AChE, BChE, COX-2, 5-LOX and α-amylase enzyme and showed high binding energies. The synthesized succinimide derivatives, i.e. compound 23, 31, 44 showed marked inhibitory activities against cyclooxygenase, lipoxygenase, α-amylase and cholinesterase enzymes. Among these three, compound 44 and 31 showed strong anti-inflammatory and anti-diabetic activity while they displayed moderate anti-cholinesterase activity supported by molecular docking results.Communicated by Ramaswamy H. Sarma.

In Silico Molecular Docking Analysis of Karanjin against Alzheimer's and Parkinson's Diseases as a Potential Natural Lead Molecule for New Drug Design, Development and Therapy

Parkinson's disease (PD) and Alzheimer's disease (AD) are neurodegenerative disorders that have emerged as among the serious health problems of the 21st century. The medications currently available to treat AD and PD have limited efficacy and are associated with side effects. Natural products are one of the most vital and conservative sources of medicines for treating neurological problems. Karanjin is a furanoflavonoid, isolated mainly from Pongamia pinnata with several medicinal plants, and has been reported for numerous health benefits. However, the effect of karanjin on AD and PD has not yet been systematically investigated. To evaluate the neuroprotective effect of karanjin, extensive in silico studies starting with molecular docking against five putative targets for AD and four targets for PD were conducted. The findings were compared with three standard drugs using Auto Dock 4.1 and Molegro Virtual Docker software. Additionally, the physiochemical properties (Lipinski rule of five), drug-likeness and parameters including absorption, distribution, metabolism, elimination and toxicity (ADMET) profiles of karanjin were also studied. The molecular dynamics (MD) simulations were performed with two selective karanjin docking complexes to analyze the dynamic behaviors and binding free energy at 100 ns time scale. In addition, frontier molecular orbitals (FMOs) and density-functional theory (DFT) were also investigated from computational quantum mechanism perspectives using the Avogadro-ORCA 1.2.0 platform. Karanjin complies with all five of Lipinski's drug-likeness rules with suitable ADMET profiles for therapeutic use. The docking scores (kcal/mol) showed comparatively higher potency against AD and PD associated targets than currently used standard drugs. Overall, the potential binding affinity from molecular docking, static thermodynamics feature from MD-simulation and other multiparametric drug-ability profiles suggest that karanjin could be considered as a suitable therapeutic lead for AD and PD treatment. Furthermore, the present results were strongly correlated with the earlier study on karanjin in an Alzheimer's animal model. However, necessary in vivo studies, clinical trials, bioavailability, permeability and safe dose administration, etc. must be required to use karanjin as a potential drug against AD and PD treatment, where the in silico results are more helpful to accelerate the drug development.

Antioxidant, Enzyme Inhibitory, and Molecular Docking Approaches to the Antidiabetic Potentials of Bioactive Compounds from Persicaria hydropiper L

Introduction

Natural products are among the most useful sources for the discovery of new drugs against various diseases. Keeping in view the ethnobotanical relevance ethnopharmacological significance of Polygonaceae family in diabetes, the current study was designed to isolate pure compounds from Persicaria hydropiper L. leaves and evaluate their in vitro and in silico antidiabetic potentials.

Methods

Six compounds were isolated from the chloroform-ethyl acetate fractions using gravity column chromatography and were subjected to structure elucidation process. Structures were confirmed using ¹H-NMR, ¹³C-NMR, and mass spectrometry techniques. Isolated phytochemicals were subjected to in vitro antidiabetic studies, including α-glucosidase, α-amylase inhibition, and DPPH, and ABTS antioxidant studies. Furthermore, the in silico binding mode of these compounds in the target enzymes was elucidated via MOE-Dock software.

Results

The isolated compounds revealed concentration-dependent inhibitions against α-glucosidase enzyme. Ph-1 and Ph-2 were most potent with 81.84 and 78.79% enzyme inhibitions at 1000 µg·mL⁻¹, respectively. Ph-1 and Ph-2 exhibited IC₅₀s of 85 and 170 µg·mL⁻¹ correspondingly. Likewise, test compounds showed considerable α-amylase inhibitions with Ph-1 and Ph-2 being the most potent. Tested compounds exhibited considerable antioxidant potentials in both DPPH and ABTS assays. Molecular simulation studies also revealed top-ranked confirmations for the majority of the compounds in the target enzymes. Highest observed potent compound was Ph-1 with docking score of −12.4286 and formed eight hydrogen bonds and three H-pi linkages with the Asp 68, Phe 157, Phe 177, Asn 241, Glu 276, His 279, Phe 300, Glu 304, Ser 308, Pro 309, Phe 310, Asp 349, and Arg 439 residues of α-glucosidase binding packets. Asp 68, Glu 276, Asp 349, and Arg 439 formed polar bonds with the 3-ethyl-2-methylpentane moiety of the ligand.

Conclusions

The isolated compounds exhibited considerable antioxidant and inhibitory potentials against vital enzymes implicated in T2DM. The docking scores of the compounds revealed that they exhibit affinity for binding with target ligands. The enzyme inhibition and antioxidant potential of the compounds might contribute to the hypoglycemic effects of the plant and need further studies.

Jatamansinol from Nardostachys jatamansi (D.Don) DC. Protects Aβ42-induced Neurotoxicity in Alzheimer's Disease Drosophila Model

Nardostachys jatamansi (D. Don) DC. is an essential plant used in Indian Ayurveda to treat neurological disorders, and it enhances memory. Its active phytochemical(s) responsible for neuroprotection is not yet studied. One of the neurological disorders, namely Alzheimer's disease (AD) causes dementia, is not having pharmacological strategies to effectively prevent the onset of AD, cure or reverse AD progression, and treat cognitive symptoms. Here is an attempt to analyze the neuroprotective effect of jatamansinol isolated from N. jatamansi against Aβ₄₂ protein-induced neurotoxicity using the Aβ₄₂ protein expressed Drosophila Alzheimer's disease (AD) model. Oregon-K (OK) and AD flies were reared on regular or jatamansinol supplemented food and analyzed their lifespan, locomotor activity, learning and memory, eye degeneration, oxidative stress levels, antioxidant activities, cholinesterase activities, Aβ₄₂ protein, and Aβ₄₂ gene expression. Jatamansinol extends the lifespan, improves locomotor activity, enhances learning and memory, and reduces Aβ₄₂ protein levels in AD flies. Jatamansinol boosts the antioxidant enzyme activities, prevents Aβ₄₂ protein-induced oxidative stress, ameliorates eye degeneration, and inhibits cholinesterase activities in the AD model. This study evidences the protective effect of jatamansinol against the Aβ₄₂ protein-induced neurotoxicity in the AD Drosophila model, suggesting its possible therapeutic potential against AD.

Phytochemical Analysis, α-Glucosidase and Amylase Inhibitory, and Molecular Docking Studies on Persicaria hydropiper L. Leaves Essential Oils

Objective

Medicinal plants and essentials oils are well known for diverse biological activities including antidiabetic potential. This study was designed to isolate essential oils from the leaves of Persicaria hydropiper L. (P. hydropiper), perform its phytochemical analysis, and explore its in vitro antidiabetic effects.

Materials and Methods

P. hydropiper leaves essential oils (Ph.Los) were extracted using a hydrodistillation apparatus and were subjected to phytochemical analysis using the gas chromatography mass spectrometry (GC-MS) technique. Ph.Lo was tested against two vital enzymes including α-glucosidase and α-amylase which are important targets in type-2 diabetes. The identified compounds were tested using in silico approaches for their binding affinities against the enzyme targets using MOE-Dock software.

Results

GC-MS analysis revealed the presence of 141 compounds among which dihydro-alpha-ionone, cis-geranylacetone, α-bulnesene, nerolidol, β-caryophyllene epoxide, and decahydronaphthalene were the most abundant compounds. Ph.Lo exhibited considerable inhibitory potential against α-glucosidase enzyme with 70% inhibition at 1000 μg mL⁻¹ which was the highest tested concentration. The inhibitory activity of positive control acarbose was 77.30 ± 0.61% at the same tested concentration. Ph.Lo and acarbose exhibited IC₅₀ of 170 and 18 µg mL⁻¹ correspondingly. Furthermore, dose-dependent inhibitions were observed for Ph.Lo against α-amylase enzyme with an IC₅₀ of 890 μg mL⁻¹. The top-ranked docking conformation was observed for β-caryophyllene epoxide with a docking score of -8.3182 against α-glucosidase, and it has established seven hydrogen bonds and one H-pi interaction at the active site residues (Phe 177, Glu 276, Arg 312, Asp 349, Gln 350, Asp 408, and Arg 439). Majority of the identified compounds fit well in the binding pocket of Tyr 62, Asp 197, Glu 233, Asp 300, His 305, and Ala 307 active residues of α-amylase. β-Caryophyllene epoxide was found to be the most active inhibitor with a docking score of -8.3050 and formed five hydrogen bonds at the active site residues of α-amylase. Asp 197, Glu 233, and Asp 300 active residues were observed to be making polar interactions with the ligand.

Conclusions

The current study revealed that Ph.Lo is rich in bioactive metabolites which might contribute to its enzyme inhibitory potential. Inhibition of these enzymes is the key target in reducing postprandial hyperglycemia. However, further detailed in vivo studies are required for their biological and therapeutic activities.

HPLC-DAD phenolics analysis, α-glucosidase, α-amylase inhibitory, molecular docking and nutritional profiles of Persicaria hydropiper L

BACKGROUND

Natural phenolic compounds and Phenolics-rich medicinal plants are also of great interest in the management of diabetes. The current study was aimed to analyze phenolics in P. hydropiepr L extracts via HPLC-DAD analysis and assess their anti-diabetic potentials using in-vitro and in-silico approaches.

METHODS

Plant crude methanolic extract (Ph.Cme) was evaluated for the presence of phenolic compounds using HPLC-DAD analysis. Subsequently, samples including crude (Ph.Cr), hexane (Ph.Hex), chloroform (Ph.Chf), ethyl acetate (Ph.EtAc), butanol (Ph.Bt), aqueous (Ph.Aq) and saponins (Ph.Sp) were tested for α-glucsidase and α-amylase inhibitory potentials and identified compounds were docked against these target enzymes using Molecular Operating Environment (MOE) software. Fractions were also analyzed for the nutritional contents and acute toxicity was performed in animals.

RESULTS

In HPLC-DAD analysis of Ph.Cme, 24 compounds were indentfied and quantified. Among these, Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside (275.4 mg g- 1), p-Coumaroylhexose-4-hexoside (96.5 mg g- 1), Quercetin-3-glucoronide (76.0 mg g- 1), 4-Caffeoylquinic acid (58.1 mg g- 1), Quercetin (57.9 mg g- 1), 5,7,3'-Trihydroxy-3,6,4',5'-tetramethoxyflavone (55.5 mg g- 1), 5-Feruloylquinic acid (45.8 mg g- 1), Cyanidin-3-glucoside (26.8 mg g- 1), Delphinidin-3-glucoside (24 mg g- 1), Quercetin-3-hexoside (20.7 mg g- 1) were highly abundant compounds. In α-glucosidase inhibition assay, Ph.Sp were most effective with IC50 value of 100 μg mL-1. Likewise in α-amylase inhibition assay, Ph.Chf, Ph.Sp and Ph.Cme were most potent fractions displayed IC50 values of 90, 100 and 200 μg mL-1 respectively. Docking with the α-glucosidase enzyme revealed top ranked conformations for majority of the compounds with Kaemferol-3-(p-coumaroyl-diglucoside)-7-glucoside as the most active compound with docking score of - 19.80899, forming 14 hydrogen bonds, two pi-H and two pi-pi linkages with the Tyr 71, Phe 158, Phe 177, Gln 181, Arg 212, Asp 214, Glu 276, Phe 300, Val 303, Tyr 344, Asp 349, Gln 350, Arg 439, and Asp 408 residues of the enzyme. Likewise, docking with α-amylase revealed that most of the compounds are well accommodated in the active site residues (Trp 59, Tyr 62, Thr 163, Leu 165, Arg 195, Asp 197, Glu 240, Asp 300, His 305, Asp 356) of the enzyme and Cyanidin-3-rutinoside displayed most active compound with docking score of - 15.03757.

CONCLUSIONS

Phytochemical studies revealed the presence of highly valuable phenolic compounds, which might be responsible for the anti-diabetic potentials of the plant samples.

Natural Product-based Nanomedicine: Recent Advances and Issues for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD) affects the elderly and is characterized by progressive neurodegeneration caused by different pathologies. The most significant challenges in treating AD include the inability of medications to reach the brain because of its poor solubility, low bioavailability, and the presence of the blood-brain barrier (BBB). Additionally, current evidence suggests the disruption of BBB plays an important role in the pathogenesis of AD. One of the critical challenges in treating AD is the ineffective treatments and their severe adverse effects. Nanotechnology offers an alternative approach to facilitate the treatment of AD by overcoming the challenges in drug transport across the BBB. Various nanoparticles (NP) loaded with natural products were reported to aid in drug delivery for the treatment of AD. The nano-sized entities of NP are great platforms for incorporating active materials from natural products into formulations that can be delivered effectively to the intended action site without compromising the material's bioactivity. The review highlights the applications of medicinal plants, their derived components, and various nanomedicinebased approaches for the treatment of AD. The combination of medicinal plants and nanotechnology may lead to new theragnostic solutions for the treatment of AD in the future.

Potential of Sorghum Polyphenols to Prevent and Treat Alzheimer's Disease: A Review Article

Alzheimer's disease (AD) is characterized by the excessive deposition of extracellular amyloid-beta peptide (Aβ) and the build-up of intracellular neurofibrillary tangles containing hyperphosphorylated tau proteins. This leads to neuronal damage, cell death and consequently results in memory and learning impairments leading to dementia. Although the exact cause of AD is not yet clear, numerous studies indicate that oxidative stress, inflammation, and mitochondrial dysfunction significantly contribute to its onset and progression. There is no effective therapeutic approach to stop the progression of AD and its associated symptoms. Thus, early intervention, preferably, pre-clinically when the brain is not significantly affected, is a better option for effective treatment. Natural polyphenols (PP) target multiple AD-related pathways such as protecting the brain from Aβ and tau neurotoxicity, ameliorating oxidative damage and mitochondrial dysfunction. Among natural products, the cereal crop sorghum has some unique features. It is one of the major global grain crops but in the developed world, it is primarily used as feed for farm animals. A broad range of PP, including phenolic acids, flavonoids, and condensed tannins are present in sorghum grain including some classes such as proanthocyanidins that are rarely found in others plants. Pigmented varieties of sorghum have the highest polyphenolic content and antioxidant activity which potentially makes their consumption beneficial for human health through different pathways such as oxidative stress reduction and thus the prevention and treatment of neurodegenerative diseases. This review summarizes the potential of sorghum PP to beneficially affect the neuropathology of AD.

Neuroprotective potentials of selected natural edible oils using enzyme inhibitory, kinetic and simulation approaches

BACKGROUND

Edible oils have proven health benefits in the prevention and treatment of various disorders since the establishment of human era. This study was aimed to appraise neuropharmacological studies on the commonly used edible oils including Cinnamomum verum (CV), Zingiber officinale (ZO) and Cuminum cyminum (CC).

METHODS

The oils were analyzed via GC-MS for identifications of bioactive compounds. Anti-radicals capacity of the oils were evaluated via 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals scavenging assays. The samples were also tested against two important acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) which are among the important drug targets in Alzheimer's disease. Lineweaver-Burk plots were constructed for enzyme inhibition studies which correspond to velocity of enzymes (Vmax) against the reciprocal of substrate concentration (Km) in the presence of test samples and control drugs following Michaelis-Menten kinetics. Docking studies on AChE target were also carried out using Molecular Operating Environment (MOE 2016.0802) software.

RESULTS

(Gas chromatography-mass spectrometry GC-MS) analysis revealed the presence of thirty-four compounds in Cinnamon oil (Cv.Eo), fourteen in ginger oil (Zo.Eo) and fifty-six in cumin oil (Cc.Eo). In the antioxidant assays, Cv.Eo, Zo.Eo and Cc.Eo exhibited IC50 values of 85, 121, 280 μg/ml sequentially against DPPH radicals. Whereas, in ABTS assay, Cv.Eo, Zo.Eo and Cc.Eo showed considerable anti-radicals potentials with IC50 values of 93, 77 and 271 μg/ml respectively. Furthermore, Cv.Eo was highly active against AChE enzyme with IC50 of 21 μg/ml. Zo.Eo and Cc.Eo exhibited considerable inhibitory activities against AChE with IC50 values of 88 and 198 μg/ml respectively. In BChE assay, Cv.Eo, Zo.Eo and Cc.Eo exhibited IC50 values of 106, 101 and 37 μg/ml respectively. Our results revealed that these oils possess considerable antioxidant and cholinesterase inhibitory potentials. As functional foods these oils can be effective remedy for the prevention and management of neurological disorders including AD. Synergistic effect of all the identified compounds was determined via binding energy values computed through docking simulations. Binding orientations showed that all the compounds interact with amino acid residues present in the peripheral anionic site (PAS) and catalytic anionic site (CAS) amino acid residues, oxyanion hole and acyl pocket via π-π stacking interactions and hydrogen bond interactions.

Cytotoxicity, anti-angiogenic, anti-tumor and molecular docking studies on phytochemicals isolated from Polygonum hydropiper L

BACKGROUND

According to the recent global cancer statistics, breast cancer is the leading cause of deaths among women with 2.3 million new cases globally. Likewise, cervical cancer is also among the leading causes of mortality among women. Polygonum hydropiper is traditionally known for its cytotoxic effects and several bioactive cytotoxic compounds were isolated from it. This study was aimed to isolate potential anticancer compounds from its most potent fractions and evaluate their anticancer potentials.

METHODS

Based on our earlier studies, active fractions including chloroform and ethyl acetate were subjected to column chromatography for isolation of compounds. Chemical structures of isolated compounds were confirmed via 1H NMR, 13C NMR, mass spectrometry. Purified compounds were tested for cytotoxicity against breast cancer cells (MCF-7), cervical cancer cells (HeLA) and NIH/3T3 fibroblasts cells cultures using MTT assy. Anti-angiogenic potentials of isolated compounds were evaluated via chorioallantoic membrane assay. Anti-tumor studies were done using Agrobacterium tumefaciens induced potato tumor assay. Furthermore, to understand the binding modes of Isolated compounds, molecular docking was performed against EGFR, HER2 and VEGFR using MOE as docking software.

RESULTS

Two bioactive compounds PH-1 (4-methyl-5-oxo-tetrahydrofuran-3-yl acetate) and PH-2 (methyl 4-hydroxy-3-methoxybenzoate) were purified from the active fractions. In cytotoxicity studies, PH-1 exhibited highest cytotoxicity against HeLA cells with 87.50% lethality at 1 mgmL-1 concentration and LD50 of 60 µgmL-1. Likewise, PH-2 showed 82.33% cytotoxicity against HeLA cells with LD50 of 160 µgmL-1. Similarly, PH-1 and PH-2 exhibited LD50 of 170 and 380 µgmL-1 respectively. Moreover, PH-1 and PH-2 were also very potent cytotoxic compounds against NIH/3T3 cells with 81.45 and 85.55% cytotoxicity at 1 mgL-1 concentration and LD50 of 140 and 58 µgL-1 respectively. Isolated compounds exhibited considerable anti-angiogenic potentials with IC50 of 340 and 500 µgL-1 respectively for PH-1 and PH-2. In anti-tumor assay, PH-1 and PH-2 exhibited 81.15 and 76.09% inhibitions with LD50 of 340 and 550 µgL-1 respectively. Both compounds selectively binds with EGFR and HER2 receptors with low binding energies. Both compounds exhibited stronger interactions with VEGFR through binding pocket residues Lys868, Val916 and Asp1046.

CONCLUSIONS

Both compounds cause considerable cytotoxicity against cancer cells. The anti-angiogenic and anti-tumor results suggests additional tumor suppressive properties. Docking analysis suggests that these compound not only has the ability to bind to EGFR and HER2 but also equally binds to VEGFR and may act as potential anti-angiogenic agents.

Extraction and Mass Spectrometric Characterization of Terpenes Recovered from Olive Leaves Using a New Adsorbent-Assisted Supercritical CO2 Process

This work reports the use of GC-QTOF-MS to obtain a deep characterization of terpenoid compounds recovered from olive leaves, which is one of the largest by-products generated by the olive oil industry. This work includes an innovative supercritical CO₂ fractionation process based on the online coupling of supercritical fluid extraction (SFE) and dynamic adsorption/desorption for the selective enrichment of terpenoids in the different olive leaves extracts. The selectivity of different commercial adsorbents such as silica gel, zeolite, and aluminum oxide was evaluated toward the different terpene families present in olive leaves. Operating at 30 MPa and 60 °C, an adsorbent-assisted fractionation was carried out every 20 min for a total time of 120 min. For the first time, GC-QTOF-MS allowed the identification of 40 terpenoids in olive leaves. The GC-QTOF-MS results indicate that silica gel is a suitable adsorbent to partially retain polyunsaturated C10 and C15 terpenes. In addition, aluminum oxide increases C20 recoveries, whereas crystalline zeolites favor C30 terpenes recoveries. The different healthy properties that have been described for terpenoids makes the current SFE-GC-QTOF-MS process especially interesting and suitable for their revalorization.