Plants-Derived Neuroprotective Agents: Cutting the Cycle of Cell Death through Multiple Mechanisms

Genus Sambucus: Exploring Its Potential as a Functional Food Ingredient with Neuroprotective Properties Mediated by Antioxidant and Anti-Inflammatory Mechanisms

The genus Sambucus, mainly Sambucus nigra, has emerged as a valuable source of bioactive compounds with potential neuroprotective properties. This review explores the antioxidant, anti-inflammatory, and neuroregenerative effects of Sambucus-derived compounds and their implications for brain health and cognitive function. In vitro studies have demonstrated the ability of Sambucus extracts to mitigate oxidative stress, modulate inflammatory responses, and promote neural stem cell proliferation and differentiation. In vivo studies using animal models of neurodegenerative diseases, such as Alzheimer's and Parkinson's, have shown that Sambucus compounds can improve cognitive function, motor performance, and neuronal survival while attenuating neuroinflammation and oxidative damage. The neuroprotective effects of Sambucus are primarily attributed to its rich content of polyphenols, particularly anthocyanins, which exert their benefits through multiple mechanisms, including the modulation of signaling pathways involved in inflammation, apoptosis, mitochondrial function, and oxidative stress. Furthermore, the potential of Sambucus as a functional food ingredient is discussed, highlighting its application in various food products and the challenges associated with the stability and bioavailability of its bioactive compounds. This review provides a comprehensive overview of the current state of research on the neuroprotective potential of Sambucus and its derivatives, offering valuable insights for the development of dietary strategies to promote brain health and prevent age-related cognitive decline.

Comparative Metabolomics and Network Pharmacology Analysis Reveal Shared Neuroprotective Mechanisms of Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb

Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb., two nootropics, are recognized in Indian Ayurvedic texts. Studies have attempted to understand their action as memory enhancers and neuroprotectants, but many molecular aspects remain unknown. We propose that Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb. share common neuroprotective mechanisms. Mass spectrometry-based untargeted metabolomics and network pharmacology approach were used to identify potential protein targets for the metabolites from each extract. Phytochemical analyses and cell culture validation studies were also used to assess apoptosis and ROS activity using aqueous extracts prepared from both herbal powders. Further, docking studies were also performed using the LibDock protocol. Untargeted metabolomics and network pharmacology approach unveiled 2751 shared metabolites and 3439 and 2928 non-redundant metabolites from Bacopa monnieri and Centella asiatica extracts, respectively, suggesting a potential common neuroprotective mechanism among these extracts. Protein-target prediction highlighted 92.4% similarity among the proteins interacting with metabolites for these extracts. Among them, kinases mapped to MAPK, mTOR, and PI3K-AKT signaling pathways represented a predominant population. Our results highlight a significant similarity in the metabolome of Bacopa monnieri (L.) Wettst and Centella asiatica (L.) Urb., and their potential protein targets may be attributed to their common neuroprotective functions.

Experimental and pharmacoinformatic approaches unveil the neuropharmacological and analgesic potential of chloroform fraction of Roktoshirinchi (Achyranthes ferruginea Roxb.)

ETHNOPHARMACOLOGICAL RELEVANCE

Achyranthes ferruginea (A. ferruginea) Roxb. is a common plant used in traditional medicine in Asia and Africa. It has a variety of local names, including "Gulmanci" in Nigeria, "Dangar" in Pakistan, "Thola" in Ethiopia, and "Roktoshirinchi" in Bangladesh. It is edible and has several ethnomedical uses for a wide range of illnesses, including hysteria, dropsy, constipation, piles, boils, asthma, and shigellosis. However, the neuropharmacological and analgesic potential of A. ferruginea remains uninvestigated.

AIM OF THE STUDY

To assess the neuropharmacological and analgesic potential of A. ferruginea through a multifaceted approach encompassing both experimental and computational models.

MATERIALS AND METHODS

Methanol was used to extract the leaves of A. ferruginea. It was then fractionated with low to high polar solvents (n-hexane, chloroform, ethyl acetate, and water) to get different fractions, including chloroform fraction (CLF). The study selected CLF at different doses and conducted advanced chemical element and proximate analyses, as well as phytochemical profiling using GC-MS. Toxicological studies were done at 300 μg per rat per day for 14 days. Cholinesterase inhibitory potential was checked using an in-vitro colorimetric assay. Acetic acid-induced writhing (AAWT) and formalin-induced licking tests (FILT) were used to assess anti-nociceptive effects. The forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM), hole board test (HBT), and light and dark box test (LDB) were among the behavioral tests used to assess depression and anxiolytic activity. Network pharmacology-based analysis was performed on selected compounds using the search tool for interacting chemicals-5 (STITCH 5), Swiss target prediction tool, and search tool for the retrieval of interacting genes and proteins (STRING) database to link their role with genes involved in neurological disorders through gene ontology and reactome analysis.

RESULTS

Qualitative chemical element analysis revealed the presence of 15 elements, including Na, K, Ca, Mg, P, and Zn. The moisture content, ash value, and organic matter were found to be 11.12, 11.03, and 88.97%, respectively. GC-MS data revealed that the CLF possesses 25 phytoconstituents. Toxicological studies suggested the CLF has no effects on normal growth, hematological and biochemical parameters, or cellular organs after 14 days at 300 μg per rat. The CLF markedly reduced the activity of both acetylcholinesterase and butyrylcholinesterase (IC50: 56.22 and 13.22 μg/mL, respectively). Promising dose-dependent analgesic activity (p < 0.05) was observed in chemically-induced pain models. The TST and FST showed a dose-dependent substantial reduction in immobility time due to the CLF. Treatment with CLF notably increased the number of open arm entries and time spent in the EPM test at doses of 200 and 400 mg/kg b.w. The CLF showed significant anxiolytic activity at 200 mg/kg b.w. in the HBT test, whereas a similar activity was observed at 400 mg/kg b.w. in the EPM test. A notable increase in the amount of time spent in the light compartment was observed in the LDB test by mice treated with CLF, suggesting an anxiolytic effect. A network pharmacology study demonstrated the relationship between the phytochemicals and a number of targets, such as PPARA, PPARG, CHRM1, and HTR2, which are connected to the shown bioactivities.

CONCLUSIONS

This study demonstrated the safety of A. ferruginea and its efficacy in attenuating cholinesterase inhibitory activity, central and peripheral pain, anxiety, and depression, warranting further exploration of its therapeutic potential.

Astragaloside IV as a Memory-Enhancing Agent: In Silico Studies with In Vivo Analysis and Post Mortem ADME-Tox Profiling in Mice

Many people around the world suffer from neurodegenerative diseases associated with cognitive impairment. As life expectancy increases, this number is steadily rising. Therefore, it is extremely important to search for new treatment strategies and to discover new substances with potential neuroprotective and/or cognition-enhancing effects. This study focuses on investigating the potential of astragaloside IV (AIV), a triterpenoid saponin with proven acetylcholinesterase (AChE)-inhibiting activity naturally occurring in the root of Astragalus mongholicus, to attenuate memory impairment. Scopolamine (SCOP), an antagonist of muscarinic cholinergic receptors, and lipopolysaccharide (LPS), a trigger of neuroinflammation, were used to impair memory processes in the passive avoidance (PA) test in mice. This memory impairment in SCOP-treated mice was attenuated by prior intraperitoneal (ip) administration of AIV at a dose of 25 mg/kg. The attenuation of memory impairment by LPS was not observed. It can therefore be assumed that AIV does not reverse memory impairment by anti-inflammatory mechanisms, although this needs to be further verified. All doses of AIV tested did not affect baseline locomotor activity in mice. In the post mortem analysis by mass spectrometry of the body tissue of the mice, the highest content of AIV was found in the kidneys, then in the spleen and liver, and the lowest in the brain.

Exploring the mechanisms of kaempferol in neuroprotection: Implications for neurological disorders

Kaempferol, a flavonoid compound found in various fruits, vegetables, and medicinal plants, has garnered increasing attention due to its potential neuroprotective effects in neurological diseases. This research examines the existing literature concerning the involvement of kaempferol in neurological diseases, including stroke, Parkinson's disease, Alzheimer's disease, neuroblastoma/glioblastoma, spinal cord injury, neuropathic pain, and epilepsy. Numerous in vitro and in vivo investigations have illustrated that kaempferol possesses antioxidant, anti-inflammatory, and antiapoptotic properties, contributing to its neuroprotective effects. Kaempferol has been shown to modulate key signaling pathways involved in neurodegeneration and neuroinflammation, such as the PI3K/Akt, MAPK/ERK, and NF-κB pathways. Moreover, kaempferol exhibits potential therapeutic benefits by enhancing neuronal survival, attenuating oxidative stress, enhancing mitochondrial calcium channel activity, reducing neuroinflammation, promoting neurogenesis, and improving cognitive function. The evidence suggests that kaempferol holds promise as a natural compound for the prevention and treatment of neurological diseases. Further research is warranted to elucidate the underlying mechanisms of action, optimize dosage regimens, and evaluate the safety and efficacy of this intervention in human clinical trials, thereby contributing to the advancement of scientific knowledge in this field.

Natural flavonoids as potential therapeutics in the management of Alzheimer's disease: a review

Alzheimer's disease (AD) is an age-dependent neurodegenerative disorder which is associated with the accumulation of proteotoxic Aβ peptides, and pathologically characterized by the deposition of Aβ-enriched plaques and neurofibrillary tangles. Given the social and economic burden caused by the rising frequency of AD, there is an urgent need for the development of appropriate therapeutics. Natural compounds are gaining popularity as alternatives to synthetic drugs due to their neuroprotective properties and higher biocompatibility. While natural compound's therapeutic effects for AD have been recently investigated in numerous in vitro and in vivo studies, only few have developed to clinical trials. The present review aims to provide a brief overview of the therapeutic effects, new insights, and upcoming perspectives of the preclinical and clinical trials of flavonoids for the treatment of Alzheimer's disease.

The Neurotherapeutic Arsenal in Cannabis sativa: Insights into Anti-Neuroinflammatory and Neuroprotective Activity and Potential Entourage Effects

Cannabis, renowned for its historical medicinal use, harbours various bioactive compounds-cannabinoids, terpenes, and flavonoids. While major cannabinoids like delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) have received extensive scrutiny for their pharmacological properties, emerging evidence underscores the collaborative interactions among these constituents, suggesting a collective therapeutic potential. This comprehensive review explores the intricate relationships and synergies between cannabinoids, terpenes, and flavonoids in cannabis. Cannabinoids, pivotal in cannabis's bioactivity, exhibit well-documented analgesic, anti-inflammatory, and neuroprotective effects. Terpenes, aromatic compounds imbuing distinct flavours, not only contribute to cannabis's sensory profile but also modulate cannabinoid effects through diverse molecular mechanisms. Flavonoids, another cannabis component, demonstrate anti-inflammatory, antioxidant, and neuroprotective properties, particularly relevant to neuroinflammation. The entourage hypothesis posits that combined cannabinoid, terpene, and flavonoid action yields synergistic or additive effects, surpassing individual compound efficacy. Recognizing the nuanced interactions is crucial for unravelling cannabis's complete therapeutic potential. Tailoring treatments based on the holistic composition of cannabis strains allows optimization of therapeutic outcomes while minimizing potential side effects. This review underscores the imperative to delve into the intricate roles of cannabinoids, terpenes, and flavonoids, offering promising prospects for innovative therapeutic interventions and advocating continued research to unlock cannabis's full therapeutic potential within the realm of natural plant-based medicine.

Identifying potential neuroprotective polyphenols targeting endoplasmic reticulum stress through an in silico approach

The endoplasmic reticulum (ER) is essential in many cellular processes, including protein processing, lipid metabolism, and calcium storage. Dysregulation of ER function has been linked with neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, etc. The primary pathological alteration explicated in the diseases is the accumulation of misfolded proteins in the neuronal cells. ER stress-associated activation of PERK-mediated pro-apoptotic cell death leads to neurodegeneration. In this study, we have primarily screened the potential polyphenols evidenced for neuroprotective activity. The 24 polyphenols were selected to explore their binding affinity towards various proteins of ER cascade such as pPERK (phospho-PERK), EIF2 (Eukaryotic Initiation Factor 2), and ATF4 (Activating Transcription Factor 4). On the basis of binding affinity, four phytopolyphenols were further selected for in-silico ADMET and molecular dynamic simulation. Among them curcumin found to be the most promising and serve as a potential hit against all three targets of ER cascade. The selected proteins' active site has demonstrated high stability of curcumin binding according to molecular dynamics findings. Though curcumin exhibited a significant hit in interaction with targets but needs to be further improved in drug-ability criteria. Thus, seventy derivatives of curcumin scaffold (from the published literature) were also screened with improve in druggability criteria, which showed good interaction with unfolded protein response related targets. The new scaffolds serve considerable potential to be developed as novel polyphenolic lead for neurodegenerative disorders.Communicated by Ramaswamy H. Sarma.

Neuroprotective potential of Marsilea quadrifolia Linn against monosodium glutamate-induced excitotoxicity in rats

Background: Excitotoxicity is a condition in which neurons are damaged/injured by the over-activation of glutamate receptors. Excitotoxins play a crucial part in the progression of several neurological diseases. Marsilea quadrifolia Linn (M. quadrifolia) is a very popular aquatic medicinal plant that has been utilised for a variety of therapeutic benefits since ancient times. Its chemical composition is diverse and includes phenolic compounds, tannins, saponins, flavonoids, steroids, terpenoids, alkaloids, carbohydrates and several others that possess antioxidant properties. Objective: The objective of the present study was to investigate the neuroprotective potential of M. quadrifolia against monosodium glutamate (MSG)-induced excitotoxicity in rats. Methods: A high-performance thin-layer chromatography (HPTLC) analysis of chloroform extract of M. quadrifolia (CEMQ) was conducted to identify the major constituents. Further, the in silico docking analysis was carried out on selected ligands. To confirm CEMQ's neuroprotective effects, the locomotor activity, non-spatial memory, and learning were assessed. Results and discussion: The present study confirmed that CMEQ contains quercetin and its derivatives in large. The in-silico findings indicated that quercetin has a better binding affinity (-7.9 kcal/mol) towards the protein target 5EWJ. Animals treated with MSG had 1) a greater reduction in the locomotor score and impairment in memory and learning 2) a greater increase in the blood levels of calcium and sodium and 3) neuronal disorganization, along with cerebral edema and neuronal degeneration in the brain tissues as compared to normal control animals. The changes were however, significantly improved in animals which received standard drug memantine (20 mg/kg) and CEMQ (200 and 400 mg/kg) as compared to the negative control. It is plausible that the changes seen with CEMQ may be attributed to the N-methyl-D-aspartate (NMDA) antagonistic properties. Conclusion: Overall, this study indicated that M. quadrifolia ameliorated MSG-induced neurotoxicity. Future investigations are required to explore the neuroprotective mechanism of M. quadrifolia and its active constituents, which will provide exciting insights in the therapeutic management of neurological disorders.

Influence of the Loading with Newly Green Silver Nanoparticles Synthesized Using Equisetum sylvaticum on the Antibacterial Activity and Surface Hardness of a Composite Resin

The aim of the study was to evaluate the antibacterial activity and surface hardness of a light-activated microhybrid composite resin modified with green silver nanoparticles (AgNPs). AgNPs were synthesized using an Equisetum sylvaticum extract and characterized through different methods such as UV-Vis, EDX, and FTIR. The obtained AgNPs were mixed with a microhybrid composite resin (Herculite XRV, Kerr Corp., Orange, CA, USA) in different concentrations: 0% (group A-control); 0.5% (group B); 1% (group C); and 1.5% (group D). A total of 120 composite resin disk-shaped samples were obtained and divided into 4 groups (n = 30) according to AgNP concentration. Each group was then divided into 2 subgroups: subgroup 1-samples were not soaked in 0.01 M NaOH solution; and subgroup 2-samples were soaked in 0.01 M NaOH solution. The antibacterial activity against Streptococcus mutans was determined using a direct contact test. A digital electronic hardness tester was used to determine the composite resin's Vickers surface hardness (VH). Statistical analysis was performed using the Mann-Whitney U and Kruskal-Wallis nonparametric tests with a confidence level of 95%. Groups C and D showed higher antibacterial activity against S. mutans when compared to the control group (p < 0.05). No significant differences were recorded between VH values (p > 0.05). The use of AgNPs synthesized from Equisetum sylvaticum as a composite resin filler in 1% wt. and 1.5% wt. reduced the activity of Streptococcus mutans. Soaking of the experimental composite resin decreased the antibacterial efficacy. The loading of a microhybrid composite resin with AgNPs in concentrations of 0.5% wt., 1% wt., and 1.5% wt. did not influence the surface hardness.

Matrine exerts its neuroprotective effects by modulating multiple neuronal pathways

Recent evidence suggests that misfolding, clumping, and accumulation of proteins in the brain may be common causes and pathogenic mechanism for several neurological illnesses. This causes neuronal structural deterioration and disruption of neural circuits. Research from various fields supports this idea, indicating that developing a single treatment for several severe conditions might be possible. Phytochemicals from medicinal plants play an essential part in maintaining the brain's chemical equilibrium by affecting the proximity of neurons. Matrine is a tetracyclo-quinolizidine alkaloid derived from the plant Sophora flavescens Aiton. Matrine has been shown to have a therapeutic effect on Multiple Sclerosis, Alzheimer's disease, and various other neurological disorders. Numerous studies have demonstrated that matrine protects neurons by altering multiple signalling pathways and crossing the blood-brain barrier. As a result, matrine may have therapeutic utility in the treatment of a variety of neurocomplications. This work aims to serve as a foundation for future clinical research by reviewing the current state of matrine as a neuroprotective agent and its potential therapeutic application in treating neurodegenerative and neuropsychiatric illnesses. Future research will answer many concerns and lead to fascinating discoveries that could impact other aspects of matrine.

Unveiling the Antioxidant, Clinical Enzyme Inhibitory Properties and Cytotoxic Potential of Tambourissa peltata Baker-An Understudied Endemic Plant

This study documents for the first time the phytochemical composition and biological activities of Tambourissa peltata Baker, an endemic plant from Mauritius. Phytochemical extraction was performed using ethyl acetate, methanol and distilled water as solvents. The phytochemical composition was determined through HPLC-MS and other standard assays. The DPPH, ABTS, FRAP, CUPRAC and phosphomolybdenum assays were employed for the determination of the antioxidant potential, whereas cell viability assays were used to determine the cytotoxicity. The highest phenolic and phenolic acid contents were obtained in the aqueous extract (179.91 ± 0.67 gallic acid equivalents/g and 55.74 ± 1.43 caffeic acid equivalents/g). The highest quantity of flavonoids was obtained in the ethyl acetate extract (28.97 ± 0.46 rutin equivalents/g). The methanolic extract was the highest source of flavonols (33.71 ± 0.13 mg catechin equivalents/g). A total of 34 phytochemicals were identified, mainly proanthocyanidins and flavonoid glycosides. The highest antioxidant activity in DPPH (973.40 ± 5.65 mg TE (Trolox equivalents)/g), ABTS (2030.37 ± 40.83 mg TE/g), FRAP (1461.39 ± 5.95 mg TE/g), CUPRAC (1940.99 ± 20.95 mg TE/g) and phosphomolybdenum (8.37 ± 0.23 mmol TE/g) assays was recorded for the aqueous extract. The ethyl acetate extract was the most active metal chelator. The highest acetylcholinesterase inhibitor was the methanolic extract, whereas the ethyl acetate extract was the most active against BChE. The tyrosinase enzyme was most inhibited by the methanolic extract. Alpha-amylase and glucosidase were most inhibited by the aqueous extract. The methanolic extract was capable of inducing cell cytotoxicity to the human colorectal carcinoma without damaging normal cells. T. peltata warrants further attention from the scientific community given its multifaceted biological properties.

Potential implications of polyphenolic compounds in neurodegenerative diseases

Neurodegenerative diseases are common chronic diseases related to progressive damage to the nervous system. Current neurodegenerative diseases present difficulties and despite extensive research efforts to develop new disease-modifying therapies, there is still no effective treatment for halting the neurodegenerative process. Polyphenols are biologically active organic compounds abundantly found in various plants. It has been reported that plant-derived dietary polyphenols may improve some disease states and promote health. Emerging pieces of evidence indicate that polyphenols are associated with neurodegenerative diseases. This review aims to overview the potential neuroprotective roles of polyphenols in most common neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and ischemic stroke.

Topiramate potential neurotoxicity and mitigating role of ginger oil in mice brain

Topiramate has multiple pharmacological mechanisms that are efficient in treating epilepsy and migraine. Ginger has been established to have gingerols and shogaols that cause migraine relief. Moreover, Topiramate has many off-label uses. Thus, it was necessary to explore the possible neurotoxicity of Topiramate and the role of ginger oil in attenuating the Topiramate neurotoxicity. Male albino mice were orally gavaged with Topiramate, ginger oil (400 mg/kg), and Topiramate plus ginger oil with the same pattern for 28 days. Oxidative stress markers, acetylcholinesterase (AchE), gamma-aminobutyric acid (GABA), and tumor necrosis factor-alpha (TNF-α) were examined. Histopathological examination, immunohistochemical glial fibrillary acidic protein (GFAP), and Bax expression analysis were detected. The GABAAR subunits, Gabra1, Gabra3, and Gabra5 expression, were assessed by RT-qPCR. The investigation showed that Topiramate raised oxidative stress markers levels, neurotransmitters, TNF-α, and diminished glutathione (GSH). In addition, Topiramate exhibited various neuropathological alterations, strong Bax, and GFAP immune-reactivity in the cerebral cortex. At the same time, the results indicated that ginger oil had no neurotoxicity. The effect of Topiramate plus ginger oil alleviated the changes induced by Topiramate in the tested parameters. Both Topiramate and ginger oil upregulated the mRNA expression of gabra1 and gabra3, while their interaction markedly downregulated them. Therefore, it could be concluded that the Topiramate overdose could cause neurotoxicity, but the interaction with ginger oil may reduce Topiramate-induced neurotoxicity and should be taken in parallel.

Screening and Structure-Activity Relationship of D2AAK1 Derivatives for Potential Application in the Treatment of Neurodegenerative Diseases

Neurodegenerative and mental diseases are serious medical, economic and social problems. Neurodegeneration is referred to as a pathological condition associated with damage to nerve cells leading to their death. Treatment of neurodegenerative diseases is at present symptomatic only, and novel drugs are urgently needed which would be able to stop disease progression. We performed screening of reactive oxygen species, reactive nitrogen species, glutathione and level intracellular Ca²⁺. The studies were assessed using one-way ANOVA of variance with Dunnett’s post hoc test. Previously, we reported D2AAK1 as a promising compound for the treatment of neurodegenerative and mental disorders. Here, we show a screening of D2AAK1 derivatives aimed at the selection of the compound with the most favorable pharmacological profile. Selected compounds cause an increase in the proliferation of a hippocampal neuron-like cell line, changes in the levels of reactive oxygen and nitrogen forms, reduced glutathione and a reduced intracellular calcium pool. Upon analyzing the structure–activity relationship, we selected the compound with the most favorable profile for a neuroprotective activity for potential application in the treatment of neurodegenerative diseases.

Medicinal Plants for Anti-neurodegenerative diseases in West Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Neurodegenerative diseases are neuronal diseases that affect the brain components by degenerating the structure and function of the central or peripheral nervous system progressively. It is a leading cause of death and affects huge amount of people worldwide. Plant-based medicines have been utilised in the therapies for many illnesses that have defied western treatments, including neurodegenerative diseases.

AIM OF THIS REVIEW

This review presents an overview of the major neurodegenerative diseases and reported prominent medicinal plants used in managing those diseases in West Africa.

METHODS

Scientific articles regarding medicinal plants and their usefulness in managing neurodegenerative diseases in West Africa were pooled from different scientific databases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to filter articles based on their relevance. Pharmacological activity, plant parts used, experimental models, and some isolated chemical compounds of those plants were summarised.

RESULTS

In the West Africa region, Fabaceae (19%) and Solanaceae (13%) have the highest representation of plant families used to treat neurological diseases, while Apocynaceae, Asteraceae, Euphorbiaceae have also been utilised. Flavonoids, alkaloids, phenolic compounds, terpenoids, coumarins present in those plants and their derivatives are reported to possess neuro-protective effects. Biochemical enzymes correlating to antioxidants, anti-inflammatory effects are the potential targets against neurodegenerative diseases.

CONCLUSION

Medicinal plants for anti-neurodegenerative diseases in West Africa have been documented with their neuropharmacological activities. Plant families such as Fabaceae, Solanaceae, Apocynaceae, Asteraceae, and Euphorbiaceae could be a major natural source for discovery of anti-neurodegenerative drugs, thus the metabolites from them should be given priority for neurological research. This review will provide clues for further investigations on the screening and development of anti-neurodegenerative natural products from West African medicinal plants.

Withania somnifera (L.) Dunal (Ashwagandha): A comprehensive review on ethnopharmacology, pharmacotherapeutics, biomedicinal and toxicological aspects

Withania somnifera (L.) Dunal (Solanaceae) has been used as a traditional Rasayana herb for a long time. Traditional uses of this plant indicate its ameliorative properties against a plethora of human medical conditions, viz. hypertension, stress, diabetes, asthma, cancer etc. This review presents a comprehensive summary of the geographical distribution, traditional use, phytochemistry, and pharmacological activities of W. somnifera and its active constituents. In addition, it presents a detailed account of its presence as an active constituent in many commercial preparations with curative properties and health benefits. Clinical studies and toxicological considerations of its extracts and constituents are also elucidated. Comparative analysis of relevant in-vitro, in-vivo, and clinical investigations indicated potent bioactivity of W. somnifera extracts and phytochemicals as anti-cancer, anti-inflammatory, apoptotic, immunomodulatory, antimicrobial, anti-diabetic, hepatoprotective, hypoglycaemic, hypolipidemic, cardio-protective and spermatogenic agents. W. somnifera was found to be especially active against many neurological and psychological conditions like Parkinson's disease, Alzheimer's disease, Huntington's disease, ischemic stroke, sleep deprivation, amyotrophic lateral sclerosis, attention deficit hyperactivity disorder, bipolar disorder, anxiety, depression, schizophrenia and obsessive-compulsive disorder. The probable mechanism of action that imparts the pharmacological potential has also been explored. However, in-depth studies are needed on the clinical use of W. somnifera against human diseases. Besides, detailed toxicological analysis is also to be performed for its safe and efficacious use in preclinical and clinical studies and as a health-promoting herb.

Search for safer and potent natural inhibitors of Parkinson's disease

After Alzheimer's disease, Parkinson's disease (PD) has taken second place in becoming one of the most commonly occurring neurological diseases being responsible for a number of disabling motor symptoms ranging from bradykinesia, akinesia, tremors to rigidity, that mostly targets the elderly population and severely disrupts their quality of life. The true underlying pathology of PD yet remains a mystery, however, recent advances in the field have pointed towards the production of α-synuclein aggregates, oxidative stress, and an imbalance between levels of acetylcholine and dopamine neurotransmitters in the brain that have been shown to result in loss of coordinated movement. Current treatments of PD include the gold standard dopamine precursor L-dopa, dopamine agonists pergolide and bromocriptine, catechol-o-methyl transferases inhibitors, entacapone and tolcapone and monoamine oxidase inhibitors such as Selegine and Rasagiline amongst several other drugs. While these drugs are successful in treating motor symptoms of the disease, they do so with a plethora of side effects that are especially debilitating to the elderly. In the recent years, a considerable amount of attention has been shifted towards phytocompounds such as flavonoids and green tea catechins due to promising experimental results. In this review, we have compiled phytocompounds that have shown potent activity against some of the most important targets for antiparkinsonian therapy. These compounds have exhibited activities that transcend the limits of simply attenuating mitochondrial oxidative stress and have opened doors to the discovery of novel lead compounds for newer, efficacious antiparkinsonian therapies with wider therapeutic windows.

The neuroprotective attribution of Ocimum basilicum: a review on the prevention and management of neurodegenerative disorders

Background

Bioactive principles from various natural resources including medicinal herbs have always played a crucial role in healthcare settings and increasingly became key players in drug discovery and development for many biopharmaceutical applications. Additionally, natural products (NPs) have immense arrangement of distinctive chemical structures with diverse functional groups that motivated numerous investigators including synthetic chemists to discover new therapeutic entities. Numerous pre-clinical investigations involving the animal models have evident the usefulness of these NPs against various human diseases including neurodegenerative disorders (NDs).

Main text

Ocimum basilicum Linn (O. basilicum L.), also known as sweet basil, is well practiced in traditional healthcare systems and has been used to treat various human illnesses, which include malaria, skin disease, diarrhea, bronchitis, dysentery, arthritis, eye diseases, and insect bites and emphasize the significance of the ethno-botanical approach as a potential source of novel drug leads With the growing interest in advanced techniques, herbal medicine and medicinal plants explorations are still considered to be a novel resource for new pharmacotherapeutic discovery and development. O. basilicum L and its bioactive principles including apigenin, eugenol, myretenal, β-sitosterol, luteolin, rosmarinic acid, carnosic acid, essential oil (EO)-rich phenolic compounds, and others like anthocyanins and flavones could be of therapeutic values in NDs by exhibiting their neuro-protective efficacy on various signaling pathways. The present comprehensive review collected various related information using the following searching engines such as PubMed, Science Direct, Google Scholar, etc. and focused mainly the English written documents. The search period comprised of last two decades until present.

Conclusion

Although these efficacious plant genera of prime importance and has potential medical and socioeconomic importance, yet the pivotal evidence for its neuroprotective potential in novel clinical trials remains lacking. However, with the available wealth of obtainable literature on this medicinal plant, which supports this review and concludes that O. basilicum L may function as a promising therapeutics for the treatment of NDs.

Neuroprotective and Antioxidant Enhancing Properties of Selective Equisetum Extracts

The sterile stems belonging to the Equisetum species are often used in traditional medicine of various nations, including Romanians. They are highly efficient in treating urinary tract infections, cardiovascular diseases, respiratory tract infections, and medical skin conditions due to their content of polyphenolic derivatives that have been isolated. In this regard, this study aimed to provide the chemical composition of the extracts obtained from the Equisetum species (E. pratense, E. sylvaticum, E. telmateia) and to investigate the biological action in vitro and in vivo. For the chemical characterization of the analyzed Equisetum species extracts, studies were performed by using ultra-high-performance liquid chromatography (UHPLC-DAD). In vitro evaluation of the antioxidant activity of the plant extracts obtained from these species of Equisetum genus was determined. The neuroprotective activity of these three ethanolic extracts from the Equisetum species using zebrafish tests was determined in vivo. All obtained results were statistically significant. The results indicate that E. sylvaticum extract has a significant antioxidant activity; whereas, E. pratense extract had anxiolytic and antidepressant effects significantly higher than the other two extracts used. All these determinations indicate promising results for the antioxidant in vitro tests and neuroprotective activity of in vivo tests, particularly mediated by their active principles.

Pharmacological insights on the antidepressant, anxiolytic and aphrodisiac potentials of Aglaonema hookerianum Schott

ETHNOPHARMACOLOGICAL RELEVANCE

Aglaonema hookerianum Schott is an ethnomedicinally important plant used to treat a variety of diseases, including sexual and depression-like disorders. However, the scientific basis underlying the aforesaid properties have not been well justified.

AIM OF THE STUDY

The present investigation aimed to investigate the anxiolytic, antidepressant and aphrodisiac potentials of methanol leaves extract of A. hookerianum (MEAH) in Swiss albino mice.

MATERIALS & METHODS

Swiss albino mice (20-30 g) were orally administrated with MEAH at the doses ranging from 100 to 400 mg/kg, b.w. The elevated plus maze (EPM) and hole board test (HBT) were performed to determine the anxiolytic activity and the forced swimming test (FST) and tail suspension test (TST) were performed to determine the antidepressant activity of MEAH. Besides, the aphrodisiac activity of MEAH was conducted through the mounting behaviour and orientation behaviour analysis. Diazepam (1 mg/kg, b.w., i.p.) for EPM and HBT; fluoxetine HCl (20 mg/kg, b.w., p.o.) for FST and TST, and sildenafil (5 mg/kg, b.w., p.o.) for the mounting behaviour analysis and orientation behaviour analysis were used as reference drugs.

RESULTS

The administration of the MEAH produced a strong (p < 0.001) dose-dependent anxiolytic effects in both HBT and EPM tests. Likewise, the extract revealed a significant (p < 0.001) reduction in the immobility time in both FST and TST as compared to the control group. Besides, the MEAH also found to possess marked aphrodisiac activity complying several facets such as an increase in the sexual performance at the highest dose (400 mg/kg, p.o.) as well as the orientation toward female mice (p < 0.001) at all tested doses.

CONCLUSION

Taken together, MEAH can be recommended as a potent source of neuroprotective and a libido-boosting drug candidate for the management of neurological and sexual disorders.

Isolation and neuroprotective prospective of novel bioactive compound "3-(3,4-dimethoxyphenyl)-1-(4-methoxyphenyl) prop-2-en-1-one" against ketamine-induced cognitive deficits in schizophrenia: an experimental study

For the first time a new flavonoid compound is isolated from the seeds of Celastrus paniculatus (CP) using different chromatographic techniques and it's structure is predicted as "3-(3,4-dimethoxyphenyl)-1-(4-methoxyphenyl)prop-2-en-1-one" by employing various spectroscopic studies. The neuroprotective potential of this flavonoid was evaluated against ketamine-induced cognitive deficits with special reference to cholinergic system in vivo. The compound has exhibited significant neuroprotective property against ketamine-induced cholinergic alterations in different brain regions of rat which are restored to normal during the treatment with the compound on par with the reference compound, clozapine. Moreover, the isolated compound was found to be non-toxic to the animal during the treatment which indicates its safety in any human health related applications and can add value to the new drug development. In conclusion, this is the first study of new flavonoid compound of CP and its protective efficacy against schizophrenia.

Codonopsis pilosula polysaccharide attenuates Aβ toxicity and cognitive defects in APP/PS1 mice

Codonopsis pilosula Polysaccharides (CPPs), a traditional Chinese medicine used for thousands of years, is a potential neuroprotective polysaccharide via a relatively poorly understood mechanism. We previously reported that CPPs attenuated tau pathology in hTau transfected mice and therefore in the current work investigated the effect of CPPs on Aβ toxicity and cognitive defects in APP/PS1 mice model. It was found that one-month intragastric administration of CPPs significantly ameliorated cognitive defects in APP/PS1 mice. In addition, CPPs treatment mitigated the loss of the synaptic plasticity and increased the synaptic proteins including synaptotagmin and PSD95. The expression of Aβ42 and Aβ40 was remarkably decreased in the hippocampus of APP/PS1 mice after CPPs treatment. We also found that CPPs coincubation significantly reduced the amount of APPβ and Aβ42 expression in cells. Intriguingly, the activity of BACE1 was decreased following CPPs treatment in both the hippocampus of APP/PS1 mice and in vitro experiments. Collectively, these results indicated that CPPs attenuated Aβ pathology in APP/PS1 mice, and down-regulating BACE1 might be the underlaying mechanism which could be a therapeutic target for alleviating cognitive defects in AD pathology.

Impact of Natural Compounds on Neurodegenerative Disorders: From Preclinical to Pharmacotherapeutics

Among the major neurodegenerative disorders (NDDs), Alzheimer’s disease (AD) and Parkinson’s disease (PD), are a huge socioeconomic burden. Over many centuries, people have sought a cure for NDDs from the natural herbals. Many medicinal plants and their secondary metabolites are reported with the ability to alleviate the symptoms of NDDs. The major mechanisms identified, through which phytochemicals exert their neuroprotective effects and potential maintenance of neurological health in ageing, include antioxidant, anti-inflammatory, antithrombotic, antiapoptotic, acetylcholinesterase and monoamine oxidase inhibition and neurotrophic activities. This article reviews the mechanisms of action of some of the major herbal products with potential in the treatment of NDDs according to their molecular targets, as well as their regional sources (Asia, America and Africa). A number of studies demonstrated the beneficial properties of plant extracts or their bioactive compounds against NDDs. Herbal products may potentially offer new treatment options for patients with NDDs, which is a cheaper and culturally suitable alternative to conventional therapies for millions of people in the world with age-related NDDs.

Larrea tridentata Extract Mitigates Oxidative Stress-Induced Cytotoxicity in Human Neuroblastoma SH-SY5Y Cells

Creosote bush (Larrea tridentata; LT) leaves extracts were tested for their potential efficacy to mitigate cellular oxidative stress on human SH-SY5Y cells. Here, the differential nuclear staining assay, a bioimager system, and flow cytometric protocols, concurrently with several specific chemicals, were used to measure the percentage of cell viability and several facets implicated in the cytoprotective mechanism of LT extracts. Initially, three LT extracts, prepared with different solvents, ethanol, ethanol:water (e/w), and water, were tested for their capacity to rescue the viability of cells undergoing aggressive H₂O₂-induced oxidative stress. Results indicate that the LT extract prepared with a mixture of ethanol:water (LT-e/w; 60:40% v/v) displayed the most effective cytoprotection rescue activity. Interestingly, by investigating the LT-e/w mechanism of action, it was found that LT-e/w extract decreases the levels of H₂O₂-provoked reactive oxidative species (ROS) accumulation, mitochondrial depolarization, phosphatidylserine externalization, caspase-3/7 activation, and poly (ADP-ribose) polymerase (PARP) cleavage significantly, which are hallmarks of apoptosis. Thus, out of the three LT extracts tested, our findings highlight that the LT-e/w extract was the most effective protective reagent on SH-SY5Y cells undergoing oxidative stress in vitro, functioning as a natural anti-apoptotic extract. These findings warrant further LT-e/w extract examination in a holistic context.

Antioxidant and Anti-inflammatory Mechanisms of Neuroprotection by Ursolic Acid: Addressing Brain Injury, Cerebral Ischemia, Cognition Deficit, Anxiety, and Depression

Ursolic acid (UA) is a pentacyclic triterpene which is found in common herbs and medicinal plants that are reputed for a variety of pharmacological effects. Both as an active principle of these plants and as a nutraceutical ingredient, the pharmacology of UA in the CNS and other organs and systems has been extensively reported in recent years. In this communication, the antioxidant and anti-inflammatory axis of UA's pharmacology is appraised for its therapeutic potential in some common CNS disorders. Classic examples include the traumatic brain injury (TBI), cerebral ischemia, cognition deficit, anxiety, and depression. The pharmacological efficacy for UA is demonstrated through the therapeutic principle of one drug → multitargets → one/many disease(s). Both specific enzymes and receptor targets along with diverse pharmacological effects associated with oxidative stress and inflammatory signalling are scrutinised.

Natural Products in Alzheimer's Disease Therapy: Would Old Therapeutic Approaches Fix the Broken Promise of Modern Medicines?

Despite extensive progress in understanding the pathology of Alzheimer's disease (AD) over the last 50 years, clinical trials based on the amyloid-beta (Aβ) hypothesis have kept failing in late stage human trials. As a result, just four old drugs of limited clinical outcomes and numerous side effects are currently used for AD therapy. This article assesses the common pharmacological targets and therapeutic principles for current and future drugs. It also underlines the merits of natural products acting through a polytherapeutic approach over a monotherapy option of AD therapy. Multi-targeting approaches through general antioxidant and anti-inflammatory mechanisms coupled with specific receptor and/or enzyme-mediated effects in neuroprotection, neuroregeneration, and other rational perspectives of novel drug discovery are emphasized.

Getting high with the most high: Entheogens in the Old Testament

This article collects evidence from psychopharmacology, scripture, and archeology to explore several preparations for consumption described in the Old Testament: Manna, Showbread, the Holy Ointment, and the Tabernacle Incense. The Ointment and the Incense are herbal preparations used by the priestly caste to facilitate a direct experience of the Israelite God. A wide variety of psychoactive components are found in these preparations, including GABA-receptor agonists and modulators, opioid receptor agonists, and other agents. They are normally broken down by the body’s enzymes, and therefore orally inactive, but the Holy Ointment also contains inhibitors specific to the enzymes in question. The preparations indicate that the ancient Israelites had a profound understanding of synergism, and the way they are consumed and the taboos around them are highly suggestive of their use as psychoactive agents.

Acanthus ebracteatus leaf extract provides neuronal cell protection against oxidative stress injury induced by glutamate

BACKGROUND

Acanthus ebracteatus (AE), an herb native to Asia, has been recognized in traditional folk medicine not only for its antioxidant properties and various pharmacological activities but also as an ingredient of longevity formulas. However, its anti-neurodegenerative potential is not yet clearly known. This work aimed to evaluate the protective effect of AE leaf extract against glutamate-induced oxidative damage in mouse hippocampal HT22 cells, a neurodegenerative model system due to a reduction in glutathione levels and an increase in reactive oxygen species (ROS).

METHODS

Cell viability, apoptosis, and ROS assays were performed to assess the protective effect of AE leaf extract against glutamate-induced oxidative toxicity in HT22 cells. The antioxidant capacity of AE was evaluated using in vitro radical scavenging assays. The subcellular localization of apoptosis-inducing factor (AIF) and the mRNA and protein levels of genes associated with the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant system were determined to elucidate the mechanisms underlying the neuroprotective effect of AE leaf extract.

RESULTS

We demonstrated that AE leaf extract is capable of attenuating the intracellular ROS generation and HT22 cell death induced by glutamate in a concentration-dependent manner. Co-treatment of glutamate with the extract significantly reduced apoptotic cell death via inhibition of AIF nuclear translocation. The increases in Nrf2 levels in the nucleus and gene expression levels of antioxidant-related downstream genes under Nrf2 control were found to be significant in cells treated with the extract.

CONCLUSIONS

The results suggested that AE leaf extract possesses neuroprotective activity against glutamate-induced oxidative injury and may have therapeutic potential for the treatment of neurodegenerative diseases associated with oxidative stress.

Determination of the Pharmacokinetics and Tissue Distribution of Methyl 3,4-Dihydroxybenzoate (MDHB) in Mice Using Liquid Chromatography-Tandem Mass Spectrometry

BACKGROUND AND OBJECTIVES

Methyl 3,4-dihydroxybenzoate (MDHB) has the potential to prevent neurodegenerative diseases (NDDs). The present work aims to reveal the pharmacokinetics and tissue distribution characteristics of MDHB.

METHODS

The pharmacokinetics and tissue distribution of MDHB were analyzed using LC-MS/MS after a single intragastric administration (50 to 450 mg/kg) in mice, and samples were collected from five animals at specific time points.

RESULTS

Pharmacokinetic parameters of MDHB following intragastric administrations were: the time to peak concentration (T_max) ranged from 0.033 to 0.07 h, the peak concentration (C_max) ranged from 12,379.158 to 109798.712 μg/l, the elimination half-life (t_1/2z) ranged from 0.153 to 1.291 h, the area under the curve (AUC_0-∞) ranged from 640.654 to 20,241.081 μg/l × h, the mean residence time (MRT_0-∞) ranged from 0.071 to 0.206 h, the apparent volume of distribution (V_z/F) ranged from 17.538 to 45.244 l/kg, and the systemic clearance (Cl_z/F) ranged from 22.541 to 80.807 l/h/kg. The oral bioavailability of MDHB was 23%. The maximum MDHB content was detected in the stomach, and the minimum content was observed in the testes; the peak content in the brain was 15,666.93 ng/g.

CONCLUSIONS

The pharmacokinetic characteristics of MDHB include fast absorption, high systemic clearance, a short half-life and an oral bioavailability of 23%. Additionally, MDHB permeates the blood-brain barrier (BBB) and is rapidly distributed to all organs. The identification of the pharmacokinetics of MDHB following its oral administration will contribute to further preclinical and clinical studies of its effects.

Targeting mTORs by omega-3 fatty acids: A possible novel therapeutic strategy for neurodegeneration?

Neurodegenerative diseases (NDs) such as Parkinson's (PD), Alzheimer's (AD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS) cause significant world-wide morbidity and mortality. To date, there is no drug of cure for these, mostly age-related diseases, although approaches in delaying the pathology and/or giving patients some symptomatic relief have been adopted for the last few decades. Various studies in recent years have shown the beneficial effects of omega-3 poly unsaturated fatty acids (PUFAs) through diverse mechanisms including anti-inflammatory effects. This review now assesses the potential of this class of compounds in NDs therapy through specific action against the mammalian target of rapamycin (mTOR) signaling pathway. The role of mTOR in neurodegenerative diseases and targeted therapies by PUFAs are discussed.

Molecular Pharmacology of Rosmarinic and Salvianolic Acids: Potential Seeds for Alzheimer's and Vascular Dementia Drugs

Both caffeic acid and 3,4-dihydroxyphenyllactic acid (danshensu) are synthesized through two distinct routs of the shikimic acid biosynthesis pathway. In many plants, especially the rosemary and sage family of Lamiaceae, these two compounds are joined through an ester linkage to form rosmarinic acid (RA). A further structural diversity of RA derivatives in some plants such as Salvia miltiorrhiza Bunge is a form of RA dimer, salvianolic acid-B (SA-B), that further give rise to diverse salvianolic acid derivatives. This review provides a comprehensive perspective on the chemistry and pharmacology of these compounds related to their potential therapeutic applications to dementia. The two common causes of dementia, Alzheimer's disease (AD) and stroke, are employed to scrutinize the effects of these compounds in vitro and in animal models of dementia. Key pharmacological mechanisms beyond the common antioxidant and anti-inflammatory effects of polyphenols are highlighted with emphasis given to amyloid beta (Aβ) pathologies among others and neuronal regeneration from stem cells.

Iridoids and Other Monoterpenes in the Alzheimer's Brain: Recent Development and Future Prospects

Iridoids are a class of monoterpenoid compounds constructed from 10-carbon skeleton of isoprene building units. These compounds in their aglycones and glycosylated forms exist in nature to contribute to mechanisms related to plant defenses and diverse plant-animal interactions. Recent studies have also shown that iridoids and other structurally related monoterpenes display a vast array of pharmacological effects that make them potential modulators of the Alzheimer’s disease (AD). This review critically evaluates the therapeutic potential of these natural products by assessing key in vitro and in vivo data published in the scientific literature. Mechanistic approach of scrutiny addressing their effects in the Alzheimer’s brain including the τ-protein phosphorylation signaling, amyloid beta (Aβ) formation, aggregation, toxicity and clearance along with various effects from antioxidant to antiinflammatory mechanisms are discussed. The drug likeness of these compounds and future prospects to consider in their development as potential leads are addressed.

Notes on the Recent History of Neuroscience in Africa

Neuroscience began with neuroanatomy and neurosurgery in Egypt more than 5000 years ago. Knowledge grew over time and specialized neurosurgery centers were established in north Africa in the eleventh century. However, it was not until the twentieth century that neuroscience research became established in sub-Saharan Africa. In most African countries, clinical research focused on understanding the rationale and improving treatment of epilepsy, infections, nutritional neuropathies, stroke and tumors. Significant advances were made. In the twenty-first century, African knowledge expanded to include all branches of neuroscience, contributing to genetic, biochemical and inflammatory determinants of brain disorders. A major focus of basic neuroscience research has been, and is, investigation of plant extracts, drugs and stress in animal models, providing insight and identifying potential novel therapies. A significant event in the history of African neuroscience was the founding of the Society of Neuroscientists of Africa (SONA) in 1993. The International Brain Research Organization (IBRO) supported SONA conferences, as well as workshops and neuroscience training schools in Africa. Thanks to their investment, as well as that of funding agencies, such as the National Institutes of Health (NIH), International Society for Neurochemistry (ISN), World Federation of Neurosurgical Societies (WFNS), World Federation of Neurology (WFN) and the International League Against Epilepsy (ILAE), neuroscience research is well-established in Africa today. However, in order to continue to develop, African neuroscience needs continued international support and African neuroscientists need to engage in policy and decision-making to persuade governments to fund studies that address the unique regional needs in Africa.