Neuroprotective effects of Bacopa monnieri in experimental model of dementia

Exploring the excellence of commercial Brahmi products from Thai online markets: Unraveling phytochemical contents, antioxidant properties and DNA damage protection

Brahmi (Bacopa monnieri (L.) Wettst.) is extensively used as a nutritional supplement in various commercial products as the plant contains abundant phytochemicals and has antioxidant properties. This study assessed the phytochemical contents, antioxidant properties, and DNA damage protection among seven Brahmi products sold through Thai online markets. Results showed that the P6 sample exhibited 3.5-7.5 fold higher bacoside contents than values observed in the other six product samples. The P6 sample also demonstrated the highest TTC, TFC, and TPC compared to the other brands. For antioxidant activity, the samples (P1-P7) displayed high capacity to scavenge DPPH free radicals with slightly significant differences ranging from 78.37 ± 0.25 to 87.21 ± 0.05 at p-value ≤0.01. The P6 sample showed strong protection against H2O2-induced oxidation of DNA strand breakage, indicating highly potent phytochemical compounds with effective free radical scavenging activity, and the ability to prevent DNA damage. The P6 sample showed promise as a valuable ingredient for the development of functional food products. However, further in vivo animal and clinical studies are required to explore the neuroprotective enhancement effects of Brahmi extracts.

Neuroprotective potential of sevoflurane against isoflurane induced cognitive dysfunction in rats via anti-inflammatory and antioxidant effect

PURPOSE

Intravenous anesthetics have excellent analgesic activity without inducing the side effect in the respiratory system. The aim and objective of the current experimental study was to access the neuroprotective effect of sevoflurane against isoflurane induced cognitive dysfunction in rats.

METHODS

Isoflurane was used for induction the neurodysfunction in the rats, and rats received the oral administration of sevoflurane (2.5, 5 and 10 mg/kg). Morris water test was carried out for the estimation of cognitive function. Neurochemical parameters, antioxidant parameters and pro-inflammatory cytokines were also estimated.

RESULTS

Sevoflurane significantly (P < 0.001) altered the neurochemical parameters such as anti-choline acetyltransferase, acetylcholine esterase, acetylcholine, protein carbonyl, choline brain-derived neurotrophic factor, and amyloid β; antioxidant parameters such as glutathione, superoxide dismutase, and malondialdehyde; pro-inflammatory cytokines include interleukin (IL-2, IL-10, IL-4, IL-6, IL-10, IL-1β), and tumor necrosis factor-α. Sevoflurane significantly reduced the activity of caspase-3.

CONCLUSIONS

Sevoflurane exhibited the neuroprotection against the cognitive dysfunction in rats via anti-inflammatory and antioxidant mechanism.

Phenyl glycosides from Bacopa monnieri with their antioxidant and anti-inflammatory activities

Bacopa monnieri (L.) Wettst (Plantaginaceae), is traditionally used in many countries as neural tonic and memory enhancer, or to relieve acute pain and inflammation. This study described the isolation and identification of one new, bacomoside D3 (1), and seven known phenyl glycosides (2 - 8). The structures of isolates were established by analysis of their spectroscopic data or hydrolysis followed by HPLC analysis together with a comparison to those reported in the literature. These compounds were evaluated for antioxidant and anti-inflammatory activities. Among them, compounds 4 and 5 exhibited strong DPPH radical scavenging activity with IC50 values of 9.77 ± 0.08 and 3.50 ± 0.04 µM, respectively. Compounds 2 and 5 significantly inhibited TNF-α production in LPS-stimulated RAW264.7 cells with IC50 values of 40.60 ± 3.05 and 38.19 ± 1.75 µM, respectively. Furthermore, the active compounds could be efficient inhibitors of oxidants by interfering with the DPPH activity in silico study.

Phytopharmaceuticals and Herbal Approaches to Target Neurodegenerative Disorders

Neurodegeneration is characterized as the continuous functional and structural loss of neurons, resulting in various clinical and pathological manifestations and loss of functional anatomy. Medicinal plants have been oppressed from ancient years and are highly considered throughout the world as a rich source of therapeutic means for the prevention, treatment of various ailments. Plant-derived medicinal products are becoming popular in India and other nations. Further herbal therapies shows good impact on chronic long term illnesses including degenerative conditions of neurons and brain. The use of herbal medicines continues to expand rapidly across the world. The active phytochemical constituents of individual plants are sometimes insufficient to achieve the desirable therapeutic effects. Combining the multiple herbs in a particular ratio (polyherbalism) will give a better therapeutic effect and reduce toxicity. Herbal-based nanosystems are also being studied as a way to enhance the delivery and bioavailability of phytochemical compounds for the treatment of neurodegenerative diseases. This review mainly focuses on the importance of the herbal medicines, polyherbalism and herbal-based nanosystems and its clinical significance for neurodegenerative diseases.

Alzheimer's disease: Molecular aspects and treatment opportunities using herbal drugs

Alzheimer's disease (AD), also called senile dementia, is the most common neurological disorder. Around 50 million people, mostly of advanced age, are suffering from dementia worldwide and this is expected to reach 100-130 million between 2040 and 2050. AD is characterized by impaired glutamatergic and cholinergic neurotransmission, which is associated with clinical and pathological symptoms. AD is characterized clinically by loss of cognition and memory impairment and pathologically by senile plaques formed by Amyloid β deposits or neurofibrillary tangles (NFT) consisting of aggregated tau proteins. Amyloid β deposits are responsible for glutamatergic dysfunction that develops NMDA dependent Ca2+ influx into postsynaptic neurons generating slow excitotoxicity process leading to oxidative stress and finally impaired cognition and neuronal loss. Amyloid decreases acetylcholine release, synthesis and neuronal transport. The decreased levels of neurotransmitter acetylcholine, neuronal loss, tau aggregation, amyloid β plaques, increased oxidative stress, neuroinflammation, bio-metal dyshomeostasis, autophagy, cell cycle dysregulation, mitochondrial dysfunction, and endoplasmic reticulum dysfunction are the factors responsible for the pathogenesis of AD. Acetylcholinesterase, NMDA, Glutamate, BACE1, 5HT6, and RAGE (Receptors for Advanced Glycation End products) are receptors targeted in treatment of AD. The FDA approved acetylcholinesterase inhibitors Donepezil, Galantamine and Rivastigmine and N-methyl-D-aspartate antagonist Memantine provide symptomatic relief. Different therapies such as amyloid β therapies, tau-based therapies, neurotransmitter-based therapies, autophagy-based therapies, multi-target therapeutic strategies, and gene therapy modify the natural course of the disease. Herbal and food intake is also important as preventive strategy and recently focus has also been placed on herbal drugs for treatment. This review focuses on the molecular aspects, pathogenesis and recent studies that signifies the potential of medicinal plants and their extracts or chemical constituents for the treatment of degenerative symptoms related to AD.

Preclinical Models for Alzheimer's Disease: Past, Present, and Future Approaches

A robust preclinical disease model is a primary requirement to understand the underlying mechanisms, signaling pathways, and drug screening for human diseases. Although various preclinical models are available for several diseases, clinical models for Alzheimer's disease (AD) remain underdeveloped and inaccurate. The pathophysiology of AD mainly includes the presence of amyloid plaques and neurofibrillary tangles (NFT). Furthermore, neuroinflammation and free radical generation also contribute to AD. Currently, there is a wide gap in scientific approaches to preventing AD progression. Most of the available drugs are limited to symptomatic relief and improve deteriorating cognitive functions. To mimic the pathogenesis of human AD, animal models like 3XTg-AD and 5XFAD are the primarily used mice models in AD therapeutics. Animal models for AD include intracerebroventricular-streptozotocin (ICV-STZ), amyloid beta-induced, colchicine-induced, etc., focusing on parameters such as cognitive decline and dementia. Unfortunately, the translational rate of the potential drug candidates in clinical trials is poor due to limitations in imitating human AD pathology in animal models. Therefore, the available preclinical models possess a gap in AD modeling. This paper presents an outline that critically assesses the applicability and limitations of the current approaches in disease modeling for AD. Also, we attempted to provide key suggestions for the best-fit model to evaluate potential therapies, which might improve therapy translation from preclinical studies to patients with AD.

Trends and challenges in phytotherapy and phytocosmetics for skin aging

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Free radicals, oxidative stress, and inflammation contribute to the etiology of most chronic diseases.

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Natural products can be incorporated into cosmetics, cosmeceuticals, and nutricosmetics to tackle inflammation-related diseases.

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The use of alternative green extraction solvents such as natural deep eutectic solvents and electrochemically reduced water is trending.

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Delivery systems are important for the enhancement of the bioavailability, stability, solubility, and controlled release profile of the bioactives.

Oxidative stress and inflammation mostly contribute to aging and age-related conditions including skin aging. The potential of natural products in the form of naturally-derived cosmetics, cosmeceuticals, and nutricosmetics have, however, not been fully harnessed. This review, thus, critically analyzes the potential roles of natural products in inflammation-related skin aging diseases due to the increasing consumers’ concerns and demands for efficacious, safe, natural, sustainable, and religiously permitted alternatives to synthetic products. The information and data were collated from various resources and literature databases such as PubMed, Science Direct, Wiley, Springer, Taylor and Francis, Scopus, Inflibnet, Google, and Google Scholar using relevant keywords and Medical Subject Headings (MeSH). The role of green extraction solvents as promising alternatives is also elucidated. The potential enhancements of the bioavailability, stability, solubility and controlled release profile of the bioactives using different delivery systems are also presented. The current potential global market value, motivators, drivers, trends, challenges, halal, and other regulatory certifications for cosmeceuticals and nutricosmetics are equally discussed. The adoption of the suggested extractions and delivery systems would enhance the stability, bioavailability, and target delivery of the bioactives.

Bacopa monnieri in the treatment of dementia due to Alzheimer's disease: A systematic review of randomised controlled trials

Background

Bacopa monnieri, a herb that has been used for many centuries in India, has shown neuroprotective effects in animal and in vitro studies; human studies on patients with Alzheimer disease have been inconclusive.

Objective

The primary objective of this review was to determine the clinical efficacy and safety of B. monnieri in persons with mild, moderate, or severe dementia, or mild cognitive impairment, due to Alzheimer disease.

Methods

We searched PubMed, Embase, Cochrane Library, clinical trial registries (World Health Organization, Australia-New Zealand, United States, and South Africa), the metaRegister of Controlled Trials, and CINAHL. We intended to include all randomized and quasi-randomized controlled trials that compared B. monnieri, its extract or active ingredients (at any dosage), with a placebo or a cholinesterase inhibitor among adults with dementia due to Alzheimer disease and in those with mild cognitive impairment due to Alzheimer disease.

Results

Our comprehensive search yielded 5 eligible studies. A total of 3 studies used B. monnieri in combination with herbal extracts while the remaining 2 used B. monnieri extracts only. Two studies compared B. monnieri with donepezil while the others used a placebo as the control. There was considerable variation in the B. monnieri dose used (ranging between 125 mg to 500 mg twice daily) and heterogeneity in treatment duration, follow-up, and outcomes. The major outcomes were Mini-Mental State Examination scores reported in 3 trials, Cognitive subscale scores of the Alzheimer’s Disease Assessment Scale in 1 study, and a battery of cognitive tests in 2 studies. Using the Cochrane risk-of-bias tool, overall, we judged all 5 studies to be at high risk of bias. While all studies reported a statistically significant difference between B. monnieri and the comparator in at least one outcome, we rated the overall quality of evidence for the Alzheimer’s Disease Assessment Scale-Cognitive Subscale, Postgraduate Institute Memory Scale, Mini-Mental State Examination, and Wechsler Memory Scale to be very low due to downgrading by 2 levels for high risk of bias and 1 more level for impreciseness due to small sample sizes and wide CIs.

Conclusions

There was no difference between B. monnieri and the placebo or donepezil in the treatment of Alzheimer disease based on very low certainty evidence. No major safety issues were reported in the included trials. Future randomized controlled trials should aim to recruit more participants and report clinically meaningful outcomes.

Trial Registration

PROSPERO CRD42020169421; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=169421

In Vitro Antiviral Activity of Potential Medicinal Plant Extracts Against Dengue and Chikungunya Viruses

Dengue and chikungunya are two important mosquito-borne infections which are known to occur extensively in tropical and subtropical areas. Presently, there is no treatment for these viral diseases. In vitro antiviral screening of 25 extracts prepared from the plants of Vitex negundo, Plumeria alba, Ancistrocladus heyneanus, Bacopa monnieri, Anacardium occidentale, Cucurbita maxima, Simarouba glauca, and Embelia ribes using different solvents and four purified compounds (anacardic acid, chloroquinone, glaucarubinone, and methyl gallate) were carried out for their anti-dengue virus (DENV) and anti-chikungunya virus (CHIKV) activities. Maximum nontoxic concentrations of the chloroform, methanol, ethyl acetate, petroleum ether, dichloromethane, and hydroalcoholic extracts of eight plants were used. The antiviral activity was assessed by focus-forming unit assay, quantitative real-time RT-PCR, and immunofluorescence assays. Extracts from Plumeria alba, Ancistrocladus heyneanus, Bacopa monnieri, and Cucurbita maxima showed both anti-DENV and CHIKV activity while extract from Vitex negundo showed only anti-DENV activity. Among the purified compounds, anacardic acid, chloroquinone and methyl gallate showed anti-dengue activity while only methyl gallate had anti-chikungunya activity. The present study had identified the plant extracts with anti-dengue and anti-chikungunya activities, and these extracts can be further characterized for finding effective phytopharmaceutical drugs against dengue and chikungunya.

The Multifaceted Role of Neuroprotective Plants in Alzheimer’s Disease Treatment

Alzheimer’s disease (AD) is an age-related, progressive neurodegenerative disorder characterized by impaired cognition, memory loss, and altered personality. Many of the available pharmaceutical treatments do not alter the onset of disease progression. Recently, alternatives to developed drug candidates have been explored including medicinal plants and herbal treatments for the treatment of AD. This article examines the role of herbal plant extracts and the neuroprotective effects as alternative modes of intervention for AD progression. These extracts contain key metabolites that culminate alterations in AD progression. The traditional plant extracts explored in this article induce a variety of beneficial properties, including antioxidants, anti-inflammatory, and enhanced cognition, while also inducing activity on AD drug targets such as Aβ degradation. While these neuroprotective aspects for AD are relatively recent, there is great potential in the drug discovery aspect of these plant extracts for future use in AD treatment.

Herbal Plethora for Management of Neurodegenerative Disorders: An Invigorating Outlook

Objective:

Oxidative stress, proteasomal impairment, mitochondrial dysfunction, and accumulation of abnormal protein aggregates have shovelled a major section of the senior population towards neurodegenerative disorders. Although age, genetic and environmental factors are thought to play a significant role, drug abuse is considered to be a potent trigger in Parkinsonism among the young generation. The present study is a critical examination of herbal resources for attenuation of neurodegeneration.

Materials and Methods:

The following electronic databases have been used to search for literature: MEDLINE, Scopus, PubMed, and EMBASE

Results :

Paying heed to the prevalence of neurodegenerative disorders such as Alzheimer’s and Parkinson’s, the current review encompasses the pathogenesis of neurodegeneration at the cellular level and possible prospects to overcome the challenge sailing through the ocean of herbal boon. The United States’s Alzheimer’s Association states that deaths attributable to heart disease in the country fell by 11% between 2000 and 2015, while deaths from neurodegenerative diseases increased by a staggering 123% making it, the world’s sixth-leading cause of death. The irreversible pathological damage amounts to cognitive loss, dementia, Amyotrophic lateral sclerosis (ALS), Parkinson’s disease (PD) Alzheimer’s disease (AD). Various herbal drugs like Brahmi, Shankhpushpi, and Amla are reported to be rich in phytoconstituents like flavonoids, glycosides, alkaloids, fatty acids, sterols, tannins, saponins, and terpenes that have remarkable antioxidant potential and could be explored for the same to prevent neuronal necrosis.

Conclusion:

It is also believed that herbal medicines are more effective and less toxic than synthetic drugs.

Bacopaside-I Alleviates the Detrimental Effects of Acute Paraquat Intoxication in the Adult Zebrafish Brain

Paraquat (PQ), an environmental neurotoxicant, causes acute fatal poisoning upon accidental or intentional ingestion (suicidal cases) worldwide. To date, an effective remedy for PQ toxicity is not available. In this study, we have evaluated the therapeutic efficacy of Bacopaside-I (BS-I), an active compound found in the plant extract of Bacopa monnieri (Brahmi), against acute PQ intoxication using zebrafish as a model organism. Adult zebrafish were injected with a dose of either 30 mg/kg or 50 mg/kg PQ. PQ-intoxicated zebrafish showed an increased rate of mortality and oxidative imbalance in their brain. Also, the proliferation of neural cells in the adult zebrafish brain was inhibited. However, when BS-I pretreated zebrafish were intoxicated with PQ, the toxic effects of PQ were ameliorated. PQ treatment also affected the expression of particular genes concerned with the apoptosis and dopamine signaling, which was not altered by BS-I administration. Our results highlight the efficiency of BS-I as a novel therapeutic agent for PQ intoxication. It further compels us to search and evaluate the molecular mechanisms targeted by BS-I to develop a potent therapy for acute PQ intoxication.

Neuroprotective Herbs for the Management of Alzheimer's Disease

Background—Alzheimer’s disease (AD) is a multifactorial, progressive, neurodegenerative disease that is characterized by memory loss, personality changes, and a decline in cognitive function. While the exact cause of AD is still unclear, recent studies point to lifestyle, diet, environmental, and genetic factors as contributors to disease progression. The pharmaceutical approaches developed to date do not alter disease progression. More than two hundred promising drug candidates have failed clinical trials in the past decade, suggesting that the disease and its causes may be highly complex. Medicinal plants and herbal remedies are now gaining more interest as complementary and alternative interventions and are a valuable source for developing drug candidates for AD. Indeed, several scientific studies have described the use of various medicinal plants and their principal phytochemicals for the treatment of AD. This article reviews a subset of herbs for their anti-inflammatory, antioxidant, and cognitive-enhancing effects. Methods—This article systematically reviews recent studies that have investigated the role of neuroprotective herbs and their bioactive compounds for dementia associated with Alzheimer’s disease and pre-Alzheimer’s disease. PubMed Central, Scopus, and Google Scholar databases of articles were collected, and abstracts were reviewed for relevance to the subject matter. Conclusions—Medicinal plants have great potential as part of an overall program in the prevention and treatment of cognitive decline associated with AD. It is hoped that these medicinal plants can be used in drug discovery programs for identifying safe and efficacious small molecules for AD.

Neuroprotection with Bacopa monnieri-A review of experimental evidence

Brahmi or aindri is a popular herb in the vast and rich compendium of herbs of Ayurveda and is botanically identified as Bacopa monnieri Linn. (BM). It is extensively used in Ayurveda and other traditional systems of medicine in the management of neurological psychiatric disorders. BM possess active principles belonging to alkaloids, glycosides, flavonoids, saponins categories. Numerous research have been undertaken across the globe to evaluate the neuroprotective potential of this herb. This review collates and summarises current (as on May 2020) published literature on Brahmi as a neuroprotective in neurological and psychiatric disorders. English language articles from databases PubMed, Scopus and Google scholar were searched using appropriate free keywords and MeSH terms related to the topic. The review demonstrates the neuroprotective potential of the Ayurveda herb Brahmi in several disorders including Alzheimer's disease, epilepsy, Parkinson's disease, Huntington's disease, cerebral ischemia and infarct and neoplasms.

The effectiveness of Bacopa monnieri (Linn.) Wettst. as a nootropic, neuroprotective, or antidepressant supplement: analysis of the available clinical data

Bacopa monnieri (Linn.) Wettst. has been used in traditional medicine as a drug to enhance and improve memory. In this regard, this study aims to provide B. monnieri's efficacy as a neuroprotective drug and as a nootropic against various neurological diseases. Literatures were collected, following Prisma guidelines, from databases, including Scopus, PubMed, Google Scholar, and Science Direct and were scrutinized using a quality scoring system. Means, standard deviations and 'n' numbers were extracted from the metrics and analyzed. Jamovi computer software for Mac was used to carry out the meta-analysis. The selected studies suggested that the plant extracts were able to show some improvements in healthy subjects which were determined in Auditory Verbal Learning Task, digit span-reverse test, inspection time task and working memory, even though it was not significant, as no two studies found statistically significant changes in the same two tests. B. monnieri was able to express modest improvements in subjects with memory loss, wherein only a few of the neuropsychological tests showed statistical significance. B. monnieri in a cocktail with other plant extracts were able to significantly reduce the effects of Alzheimer's disease, and depression which cannot be solely credited as the effect of B. monnieri. Although in one study B. monnieri was able to potentiate the beneficial effects of citalopram; on the whole, currently, there are only limited studies to establish the memory-enhancing and neuroprotective effects of B. monnieri. More studies have to be done in the future by comparing the effect with standard drugs, in order to establish these effects clinically in the plant and corroborate the preclinical data.

Indian Medicinal Herbs and Formulations for Alzheimer's Disease, from Traditional Knowledge to Scientific Assessment

Cognitive impairment, associated with ageing, stress, hypertension and various neurodegenerative disorders including Parkinson's disease and epilepsy, is a major health issue. The present review focuses on Alzheimer's disease (AD), since it is the most important cause of cognitive impairment. It is characterized by progressive memory loss, language deficits, depression, agitation, mood disturbances and psychosis. Although the hallmarks of AD are cholinergic dysfunction, β-amyloid plaques and neurofibrillary tangle formation, it is also associated with derangement of other neurotransmitters, elevated levels of advanced glycation end products, oxidative damage, neuroinflammation, genetic and environmental factors. On one hand, this complex etiopathology makes a response to commonly used drugs such as donepezil, rivastigmine, galantamine and memantine less predictable and often unsatisfactory. On the other hand, it supports the use of herbal medicines due to their nonspecific antioxidant and anti-inflammatory activity and specific cholinesterase inhibitory activity. The popularity of herbal medicines is also increasing due to their perceived effectiveness, safety and affordability. In the present article, the experimental and clinical evidence have been reviewed for various Indian herbal medicines such as Centella asiatica, Bacopa monnieri, Curcuma longa, Clitoria ternatea, Withania somnifera, Celastrus paniculatus, Evolvulus alsinoides, Desmodium gangeticum, Eclipta alba, Moringa oleifera and Convolvulus pluricaulis, which have shown potential in cognitive impairment. Some commonly available herbal formulations for memory impairment in India have also been reviewed.

Traditional Herbal Medicines Against CNS Disorders from Bangladesh

The majority of the population in Bangladesh uses traditional plant-based medicines to manage various ailments, including central nervous system (CNS) disorders. This review presents ethnobotanical information and relevant scientific studies on plants used in traditional healthcare for the management of various CNS disorders in Bangladesh. The information on the medicinal plants of Bangladesh effective against CNS disorders published in scientific journals, books, and reports was compiled from different electronic databases using specific key words. The present article provides comprehensive information on a total of 224 medicinal plant species belonging to 81 families used for the treatment of CNS disorders by the various peoples of Bangladesh. In total, we reviewed more than 290 relevant papers. In this study, leaves were found as the most often used plant organ, followed by roots, fruits, whole plants, barks, seeds, stems, rhizomes, and flowers. The Fabaceae family contributes the highest number of used species, followed by Rubiaceae, Lamiaceae, Cucurbitaceae, Vitaceae, Euphorbiaceae, Malvaceae, and Zingiberaceae. The most frequently used species (in decreasing order) are Asparagus racemosus, Centella asiatica, Stephania japonica, Aegle marmelos, Coccinia grandis, Tabernaemontana divaricata, Bacopa monnieri, Abroma augusta, and Scoparia dulcis. This review may serve as a starting point for a rational search for neuroactive natural products against CNS disorders within the Flora of Bangladesh.

Worldwide Research Trends on Medicinal Plants

The use of medicinal plants has been done since ancient times and may even be considered the origin of modern medicine. Compounds of plant origin have been and still are an important source of compounds for drugs. In this study a bibliometric study of all the works indexed in the Scopus database until 2019 has been carried out, analyzing more than 100,000 publications. On the one hand, the main countries, institutions and authors researching this topic have been identified, as well as their evolution over time. On the other hand, the links between the authors, the countries and the topics under research have been analyzed through the detection of communities. The last two periods, from 2009 to 2014 and from 2015 to 2019, have been examined in terms of research topics. It has been observed that the areas of study or clusters have been reduced, those of the last period being those engaged in unclassified drug, traditional medicine, cancer, in vivo study—antidiabetic activity, and animals—anti-inflammatory activity. In summary, it has been observed that the trend in global research is focused more on the search for new medicines or active compounds rather than on the cultivation or domestication of plant species with this demonstrated potential.

Virgin Coconut Oil Ameliorates Colchicine Induced Cognitive Dysfunction- A Preclinical Study

Background : Virgin coconut oil (VCO) has been identified as a potential cognitive strengthener associated with Alzheimer’s disease (AD). It contains medium chain fatty acids (MCFA) which are absorbed and easily metabolized by the liver to form ketone bodies. Ketone bodies are converted to acetyl Co-A in the brain which then enters the citric acid cycle to provide ATP and also serves as precursors of acetylcholine in neurons. Sunflower oil (SO) contains poly unsaturated fatty acids which has both anti-inflammatory and neuroprotective actions. To compare the neuroprotective effects of VCO and SO on biochemical parameters involved in the cognitive dysfunction induced by colchicine through intracerebroventricular (i.c.v) route.To assess the role of polyphenols and MCFA present in VCO in preventing oxidative stress and its influence on in neuroprotection and memory enhancement. Methods: In the present study, we induced dementia through i.c.v injection of colchicine after giving the diet enriched VCO and SO in rats for 60 days. Rats were sacrificed on the 22nd day after the administration of colchicine. Behavioral parameters were assessed during the study period and biochemical estimations were performed using frontal cortex and hippocampus isolated from rat brain. Results: From the memory and learning tests by Morris water maze, VCO treated group performed better than SO treated rats. VCO reversed the antagonistic effects induced by colchicine by decreasing the acetylcholinesterase and malondialdehyde levels and increasing the levels of catalase and superoxide dismutase. SO only reduced malondialdehyde levels in cortex and hippocampus. Conclusion: The results demonstrated potential beneficiary effects of VCO in the cognitive dysfunction induced by colchicine by enhancing acetylcholine levels in the frontal cortex and hippocampus and also by reducing oxidative stress induced by physiological oxidants.

Bacopa monnieri (L.) wettst. Extract protects against glutamate toxicity and increases the longevity of Caenorhabditis elegans

Background

Neurodegenerative diseases, such as Alzheimer’s disease, cause a great deal of suffering for both patients and carers. Bacopa monnieri (L.) wettst. Is known for its memory-enhancing properties, and is of great interest in treating neurodegenerative disease.

Aims

This study aimed to evaluate B.monnieri against glutamate toxicity, and identify whether B.monnieri reduces mitochondrial and ER stress, as well as to measure B.monnieri’s effect on the life span and aging of Caenorhabditis elegans. We hypothesized that B.monnieri would prevent cellular oxidative stress, prevent mitochondrial/ER stress, and increase the life span while reducing signs of aging in C.elegans.

Experimental procedures

Glutamate toxicity was measured using viable cell staining assays and the MTT assay. ROS and mitochondrial stress were assessed by H₂DCFDA and Rodamine123 staining, with fluorescence/confocal microscopy. C.elegans’ median and maximum life span were measured, in response to B.monnieri treatment, along with lipofuscin imaging to measure the health of the C.elegans population.

Results

B.monnieri hexane extract (but not ethanol extract) prevented the toxicity of 5 mM glutamate in HT-22 cells. We found that the mechanism involves the reduction of ROS production and the prevention of mitochondrial and ER stress. Furthermore, we showed that B.monnieri could increase the median and maximal lifespan of wild type C.elegans, maintain a younger appearing phenotype in the aged C.elegans.

Conclusions

In conclusion, B.monnieri prevents mitochondrial, and oxidative stress in the cultured cells. Furthermore, it can prolong the healthy lifespan of C.elegans, indicating that B.monnieri the potential for therapeutic and preventative use in neurodegenerative disease.

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First B.monnieri study to investigate the HT-22 cell glutamate toxicity model.

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B.monnieri protects HT-22 cells from oxidative stress caused by glutamate toxicity.

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B.monnieri prevents ER stress, changing the expression s of ER Stress proteins CHOP and ERP57.

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B.monnieri prevents mitochondrial stress, preventing mitochondrial leakage.

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B.monnieri increases the median and maximal life span, and reduces aging in wild type C.elegans.

Insights Into the Molecular Aspects of Neuroprotective Bacoside A and Bacopaside I

Bacopa monnieri, commonly known as Brahmi, has been extensively used as a neuromedicine for various disorders such as anxiety, depression and memory loss. Chemical characterization studies revealed the major active constituents of the herb as the triterpenoid saponins, bacosides. Bacoside A, the vital neuroprotective constituent, is composed of four constituents viz., bacoside A3, bacopaside II, jujubogenin isomer of bacopasaponin C (bacopaside X) and bacopasaponin C. B. monnieri extracts as well as bacosides successfully establish a healthy antioxidant environment in various tissues especially in the liver and brain. Free radical scavenging, suppression of lipid peroxidation and activation of antioxidant enzymes by bacosides help to attain a physiological state of minimized oxidative stress. The molecular basis of neuroprotective activity of bacosides is attributed to the regulation of mRNA translation and surface expression of neuroreceptors such as AMPAR, NMDAR and GABAR in the various parts of the brain. Bioavailability as well as binding of neuroprotective agents (such as bacosides) to these receptors is controlled by the Blood Brain Barrier (BBB). However, nano conversion of these drug candidates easily resolves the BBB restriction and carries a promising role in future therapies. This review summarizes the neuroprotective functions of B. monnieri extracts as well as its active compounds (bacoside A, bacopaside I) and the molecular mechanisms responsible for these pharmacological activities.

Bacopa monnieri prevents colchicine-induced dementia by anti-inflammatory action

Inflammation is considered as an early event in the development of Alzheimer's disease (AD) that precedes the formation of Aβ plaques and neurofibrillary tangles. Therefore, strategies aimed at attenuating inflammation by phytochemicals may be a potential therapeutic intervention against AD. The present study was designed to evaluate if colchicine-induced inflammation and Aβ production could be prevented by Bacopa monnieri (BM) supplementation. Dementia was induced by a single intracerebroventicular injection of colchicine (15 μg/5 μl), whereas, BM extract was administered orally (50 mg/kg body weight, daily) for 15 days. Assessment of cognitive functions using Morris water maze revealed deficits in colchicine administered animals. This was accompanied by significant increase in oxidative stress in terms of accentuated ROS and NO production. Expression of pro-inflammatory cytokines (IL-6, TNF-α) and chemokine (MCP-1) increased in the brain regions. Furthermore, COX-2 and iNOS expression also increased significantly in the brain regions of colchicine-administered animals. In addition, BACE-1 activity increased in the colchicine treated animals, which was accompanied by enhanced Aβ production. On the other hand, BM supplementation was able to improve cognitive functions, suppress Aβ formation by reducing BACE-1 activity. Inflammatory and oxidative stress markers were attenuated in the brain regions of BM supplemented animals. Taken together, the findings reveal that BM reverses colchicine-induced dementia by its anti-inflammatory and anti-oxidant action suggesting that it may be an effective therapeutic intervention to ameliorate progression of AD.

Medicinal plants with acetylcholinesterase inhibitory activity

Alzheimer's disease, a progressive neurodegenerative disease, is characterised by hypofunction of acetylcholine (ACh) neurotransmitter in the distinct region of brain. Acetylcholinesterase (AChE) is an enzyme that metabolises the ACh at synaptic cleft resulting in Alzheimer's disease. Medicinal plants have been used to treat numerous ailments and improve human health from ancient time. A traditional system of medicine is long recognised for its effective management of neurological disorders. The present review confers the scope of some common medicinal plants with a special focus on AChE-mediated central nervous system complications especially Alzheimer's disease. Literature suggests that medicinal plants reduce neuronal dysfunctions by reducing AChE activity in different brain regions. In some instances, activation of AChE activity by medicinal plants also showed therapeutic potential. In conclusion, medicinal plants have a wide scope and possess therapeutic potential to efficiently manage neurological disorders associated with AChE dysregulation.

Pharmacognostical Sources of Popular Medicine To Treat Alzheimer's Disease

BACKGROUND

A large number of classical and recently discovered plants are indicated in preventing and/or treating Alzheimer's disease (AD).

OBJECTIVE

Name of plants with their anti-AD effects are important for their further use and investigation.

METHOD

A short overview of AD is given; anti-Alzheimer plants are given in a Table.

RESULTS

Various medicinal plants are listed here as sources of popular medicines to be used in cases when patients are afraid of developing and/or suffer from AD. Some of these plants have been used for centuries. The major sources in the literature, over one hundred of references are given for plants that show beneficial effect on the progress of AD.

CONCLUSION

Plant extracts are widely used addition to the synthetic drugs approved by various administrative authorities to stop/slow down the progress of symptoms of AD.

The effect of Bacopa monnieri on gene expression levels in SH-SY5Y human neuroblastoma cells

Bacopa monnieri is a plant used as a nootropic in Ayurveda, a 5000-year-old system of traditional Indian medicine. Although both animal and clinical studies supported its role as a memory enhancer, the molecular and cellular mechanism underlying Bacopa's nootropic action are not understood. In this study, we used deep sequencing (RNA-Seq) to identify the transcriptome changes upon Bacopa treatment on SH-SY5Y human neuroblastoma cells. We identified several genes whose expression levels were regulated by Bacopa. Biostatistical analysis of the RNA-Seq data identified biological pathways and molecular functions that were regulated by Bacopa, including regulation of mRNA translation and transmembrane transport, responses to oxidative stress and protein misfolding. Pathway analysis using the Ingenuity platform suggested that Bacopa may protect against brain damage and improve brain development. These newly identified molecular and cellular determinants may contribute to the nootropic action of Bacopa and open up a new direction of investigation into its mechanism of action.

Neurocognitive Effect of Nootropic Drug Brahmi (Bacopa monnieri) in Alzheimer's Disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease of the elderly. The rapid increase in its incidence has necessitated development of newer drugs. Ayurvedic herbal medications are increasingly researched due to their biosafety profile and usefulness in cognitive impairment. In this article, we critically reviewed one such Medhya Rasayana (nootropic drug) Brahmi-derived from extract of Bacopa monnieri (EBm). Studies have shown that EBm promotes free radical scavenger mechanisms and protects cells in prefrontal cortex, hippocampus, and striatum against cytotoxicity and DNA damage implicated in AD. It also reduces lipoxygenase activity reducing lipid peroxidation, increases glutathione peroxidase and chelates iron. Administration of EBm was seen to protect the cholinergic neurons and reduce anticholinesterase activity comparable to donepezil, rivastigmine, and galantamine. It also reduces hippocampal β-amyloid deposition and stress-induced hippocampal damage. The neuroprotective effect of EBm is also due to nitric oxide-mediated cerebral vasodilation. EBm improved the total memory score and maximum improvement was seen in logical memory and paired associate learning in humans and reversed phenytoin-induced memory impairment in experimental model. EBm has not shown any serious clinical, neurological, hematological complications, or vital organs damage in experimental studies. Rats showed marked reduction in fertility; however, libido was unaffected. There is no experimental evidence of genotoxicity or teratogenesis by use of EBm. Mild nausea and gastrointestinal upset are seen in humans. Brahmi promises to be a novel agent in AD; however, further human trials are recommended to verify the efficacy and rule out any side effects as evidenced by the experimental models.

Caffeic Acid Derivatives from Bacopa monniera Plants as Inhibitors of Pancreatic Lipase Activity and their Structural Requirements

The methanol extract of whole Bacopa monniera plants inhibited pancreatic lipase activity in vitro. From this extract we have reported the isolation of 11 triterpene glycosides and 5 phenylethanoid- and/or phenylpropanoid- glycosides. In this paper, we describe the effects of the methanol extract and/or its constituents on pancreatic lipase activity and the isolation of an active constituent, desrhamnosyl isoacteoside. In addition, the structural requirements for its inhibitory effects were examined. We also examined the effects on the elevation of plasma triglyceride (TG) levels in olive oil loaded mice. The major active constituents, desrhamnosyl isoacteoside and plantainoside B, reduced plasma TG levels in the mice. The inhibitory effects of B. monniera and its constituents on pancreatic lipase activity and plasma TG level are reported for the first time.

Toxin-Induced Experimental Models of Learning and Memory Impairment

Animal models for learning and memory have significantly contributed to novel strategies for drug development and hence are an imperative part in the assessment of therapeutics. Learning and memory involve different stages including acquisition, consolidation, and retrieval and each stage can be characterized using specific toxin. Recent studies have postulated the molecular basis of these processes and have also demonstrated many signaling molecules that are involved in several stages of memory. Most insights into learning and memory impairment and to develop a novel compound stems from the investigations performed in experimental models, especially those produced by neurotoxins models. Several toxins have been utilized based on their mechanism of action for learning and memory impairment such as scopolamine, streptozotocin, quinolinic acid, and domoic acid. Further, some toxins like 6-hydroxy dopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and amyloid-β are known to cause specific learning and memory impairment which imitate the disease pathology of Parkinson's disease dementia and Alzheimer's disease dementia. Apart from these toxins, several other toxins come under a miscellaneous category like an environmental pollutant, snake venoms, botulinum, and lipopolysaccharide. This review will focus on the various classes of neurotoxin models for learning and memory impairment with their specific mechanism of action that could assist the process of drug discovery and development for dementia and cognitive disorders.

Neuroprotective, Neurotrophic and Anti-oxidative Role of Bacopa monnieri on CUS Induced Model of Depression in Rat

Major depression is a life threatening neuropsychiatric disorder that produces mental illness and major cause of morbidity. The present study was conducted to evaluate the neuroprotective, neurotrophic and antioxidant potential of Bacopa monnieri extract (BME) on chronic unpredictable stress (CUS) induced behavioral depression in rats. Behavioral tests were carried out for investigation of antidepressant like effects of BME, and potential mechanism was assessed by determining neurotrophin level and hippocampal neurogenesis. Depressive-like behavior was assessed by shuttle-box escape test, forced swim test and tail suspension test. Effect of BME on hypothalamic-pituitary-adrenal (HPA) axis was evaluated by measuring the plasma level of adrenocorticotropic hormone (ACTH) and corticosterone. The expression of brain derived neurotrophic factor (BDNF), neuronal marker doublecortin (DCX) in the hippocampus were measured and hippocampal neurogenesis was investigated by 5-bromo-2-deoxyuridine/neuronal nuclei (BrdU/NeuN). In addition, effects of BME on oxidative stress markers were also measured in the hippocampus of CUS exposed rats. The results indicated that BME significantly able to attenuate the depressive-like behaviors, normalized the levels of ACTH, corticosterone, and up-regulate the expression of BDNF, DCX and BrdU/NeuN in CUS induced rats compared to BME treated rats. It is also found that BME significantly increased the activity of antioxidant enzymes on CUS induced rats. These findings revealed that BME exerted neuroprotective effects possibly by promoting hippocampal neurogenesis with elevation of BDNF level and antioxidant defense against oxidative stress.

Acute and chronic toxicities of Bacopa monnieri extract in Sprague-Dawley rats

BACKGROUND

Bacopa monnieri is a medicinal plant which has long been used in Ayurvedic medicines to augment brain function and to improve memory. The purpose of our study was to identify and evaluate possible toxic effects of B. monnieri extract in rats by assessing hematological, biochemical, and histopathological parameters.

METHODS

Acute oral toxicity of Bacopa monnieri extract was studied in female rats by giving a single orally administered dose at a level of 5,000 mg/kg. The rats were monitored for toxic signs for 14 days. In the chronic toxicity test, groups of both female and male rats were given daily oral doses of B. monnieri extract at dose levels of either 30, 60, 300 or 1,500 mg/kg for 270 days. The behavior and health of the animals was then monitored. At the end of the observation period, the body and organ weights of the rats in each group were measured. Blood was collected and necropsy was performed to evaluate their hematology, blood clinical chemistry, and microanatomy.

RESULTS

The acute toxicity test found no significant differences between the experimental and the control group rats. In the chronic toxicity test, animal behavior and health of the experimental groups were normal, just as in the control rats. All values of other parameters assessed remained within the normal range.

CONCLUSION

A single oral administration of B. monnieri extract at the dose of 5,000 mg/kg did not cause any serious undesirable effects. B. monnieri extract at doses of 30, 60, 300 and 1,500 mg/kg given for 270 days did not produce any toxicity in rats.

Chemical structures of constituents from the whole plant of Bacopa monniera

Two new dammarane-type triterpene oligoglycosides, bacomosaponins A and B, and three new phenylethanoid glycosides, bacomosides A, B1, and B2, were isolated from the whole plant of Bacopa monniera Wettst. The chemical structures of the new constituents were characterized on the basis of chemical and physicochemical evidence. In the present study, bacomosaponins A and B with acyl groups were obtained from the whole plant of B. monniera. This is the first report of acylated dammarane-type triterpene oligoglycosides isolated from B. monniera. In addition, dammarane-type triterpene saponins significantly inhibited the aggregation of 42-mer amyloid β-protein.

Standardized Bacopa monnieri extract ameliorates acute paraquat-induced oxidative stress, and neurotoxicity in prepubertal mice brain

OBJECTIVES

Bacopa monnieri (BM), an ayurvedic medicinal plant, has attracted considerable interest owing to its diverse neuropharmacological properties. Epidemiological studies have shown significant correlation between paraquat (PQ) exposure and increased risk for Parkinson's disease in humans. In this study, we examined the propensity of standardized extract of BM to attenuate acute PQ-induced oxidative stress, mitochondrial dysfunctions, and neurotoxicity in the different brain regions of prepubertal mice.

METHODS

To test this hypothesis, prepubertal mice provided orally with standardized BM extract (200 mg/kg body weight/day for 4 weeks) were challenged with an acute dose (15 mg/kg body weight, intraperitoneally) of PQ after 3 hours of last dose of extract. Mice were sacrificed after 48 hours of PQ injection, and different brain regions were isolated and subjected to biochemical determinations/quantification of central monoamine (dopamine, DA) levels (by high-performance liquid chromatography).

RESULTS

Oral supplementation of BM for 4 weeks resulted in significant reduction in the basal levels of oxidative markers such as reactive oxygen species (ROS), malondialdehyde (MDA), and hydroperoxides (HP) in various brain regions. PQ at the administered dose elicited marked oxidative stress within 48 hours in various brain regions of mice. However, BM prophylaxis significantly improved oxidative homeostasis by restoring PQ-induced ROS, MDA, and HP levels and also by attenuating mitochondrial dysfunction. Interestingly, BM supplementation restored the activities of cholinergic enzymes along with the restoration of striatal DA levels among the PQ-treated mice.

DISCUSSION

Based on these findings, we infer that BM prophylaxis renders the brain resistant to PQ-mediated oxidative perturbations and thus may be better exploited as a preventive approach to protect against oxidative-mediated neuronal dysfunctions.

Indian Herbs for the Treatment of Neurodegenerative Disease

Ayurveda, an ancient system of medicine that is indigenous to India, is believed to be the world's oldest comprehensive health-care system and is now one of the most recognized and widely practiced disciplines of alternative medicine in the world. Medicinal herbs have been in use for treating diseases since ancient times in India. Ayurvedic therapies with medicinal herbs and herbomineral products generally provide relief without much adverse effects even after prolonged administration. Neurodegenerative disorders are a major cause of mortality and disability, and increasing life spans represent one of the key challenges of medical research. Ayurvedic medicine describes most neurodegenerative diseases and has defined a number of plants with therapeutic benefits for the treatment of neurodegenerative diseases having antioxidant activities. In this chapter, the role of four important Ayurvedic medicinal plants, viz., Withania somnifera (ashwagandha), Bacopa monnieri (brahmi), Centella asiatica (gotu kola), and Mucuna pruriens (velvet bean), on neurodegenerative diseases are discussed.

Effects of five Ayurvedic herbs on locomotor behaviour in a Drosophila melanogaster Parkinson's disease model

Current conventional treatments for Parkinson's disease (PD) are aimed at symptom management, as there is currently no known cure or treatment that can slow down its progression. Ayurveda, the ancient medical system of India, uses a combination of herbs to combat the disease. Herbs commonly used for this purpose are Zandopa (containing Mucuna pruriens), Withania somnifera, Centella asiatica, Sida cordifolia and Bacopa monnieri. In this study, these herbs were tested for their potential ability to improve climbing ability of a fruit fly (Drosophila melanogaster) PD model based on loss of function of phosphatase and tensin-induced putative kinase 1 (PINK1). Fruit flies were cultured on food containing individual herbs or herbal formulations, a combination of all five herbs, levodopa (positive control) or no treatment (negative control). Tests were performed in both PINK1 mutant flies and healthy wild-type (WT) flies. A significant improvement in climbing ability was observed in flies treated with B. monnieri compared with untreated PINK1 mutant flies. However, a significant decrease in climbing ability was observed in WT flies for the same herb. Centella asiatica also significantly decreased climbing ability in WT flies. No significant effects were observed with any of the other herbs in either PINK1 or WT flies compared with untreated flies.

Clitoria ternatea ameliorated the intracerebroventricularly injected streptozotocin induced cognitive impairment in rats: behavioral and biochemical evidence

RATIONALE

Clitoria ternatea, commonly known as Aparajita, is used as Medhya rasayana in Ayurveda. The role of C. ternatea in experimental models of cognitive impairment is yet to be explored.

OBJECTIVES

The present study was designed to study the effect of aqueous and hydroalcoholic extracts of C. ternatea on biochemical and behavioral parameters related to cognitive impairment in in vitro and in vivo studies.

METHODS

In vitro free radical scavenging and enzyme-inhibitory (cholinesterase, glycogen synthase kinase-3-β, rho kinase, prolyl endopeptidase, catechol-O-methyl transferase, and lipoxygenase) activities of aqueous and hydroalcoholic extracts of C. ternatea plant were evaluated. Based on in vitro results, hydroalcoholic extract of C. ternatea (100, 300, and 500 mg/kg, p.o.) was selected for evaluation in intracerebroventricularly injected streptozotocin (STZ)-induced cognitive impairment in male Wistar rats. Behavioral assessment was performed at baseline and on the 14th, 21st, and 28th days after STZ injection using elevated plus maze, passive avoidance, Morris water maze, and photoactometer. Oxidative stress parameters (malondialdehyde, reduced glutathione, nitric oxide levels, and superoxide dismutase activity), cholinesterase activity, and rho kinase (ROCK II) expression were studied in cerebral cortex and hippocampus of rats' brain at the end of the study.

RESULTS

The hydroalcoholic extract possessed significantly more in vitro antioxidant and enzyme-inhibitory activities as compared to aqueous extract. The hydroalcoholic extract of C. ternatea prevented STZ-induced cognitive impairment dose dependently by reducing oxidative stress, cholinesterase activity, and ROCK II expression.

CONCLUSION

In vitro and in vivo results suggest the potential of hydroalcoholic extract of C. ternatea for treatment of cognitive deficit in neurological disorders.

Bacopa monnieri ameliorates memory deficits in olfactory bulbectomized mice: possible involvement of glutamatergic and cholinergic systems

This study investigated the effects of alcoholic extract of Bacopa monnieri (L.) Wettst. (BM) on cognitive deficits using olfactory bulbectomized (OBX) mice and the underlying molecular mechanisms of its action. OBX mice were treated daily with BM (50 mg/kg, p.o.) or a reference drug, tacrine (2.5 mg/kg, i.p.), 1 week before and continuously 3 days after OBX. Cognitive performance of the animals was analyzed by the novel object recognition test, modified Y maze test, and fear conditioning test. Brain tissues of OBX animals were used for neurochemical and immunohistochemical studies. OBX impaired non-spatial short-term memory, spatial working memory, and long-term fair memory. BM administration ameliorated these memory disturbances. The effect of BM on short-term memory deficits was abolished by a muscarinic receptor antagonist, scopolamine. OBX downregulated phosphorylation of synaptic plasticity-related signaling proteins: NR1 subunit of N-methyl-D-aspartate receptor, glutamate receptor 1 (GluR1), and calmodulin-dependent kinase II but not cyclic AMP-responsive element binding protein (CREB), and reduced brain-derived neurotrophic factor (BDNF) mRNA in the hippocampus. OBX also reduced choline acetyltransferase in the hippocampus and cholinergic neurons in the medial septum, and enlarged the size of lateral ventricle. BM administration reversed these OBX-induced neurochemical and histological alterations, except the decrease of GluR1 phosphorylation, and enhanced CREB phosphorylation. Moreover, BM treatment inhibited ex vivo activity of acetylcholinesterase in the brain. These results indicate that BM treatment ameliorates OBX-induced cognition dysfunction via a mechanism involving enhancement of synaptic plasticity-related signaling and BDNF transcription and protection of cholinergic systems from OBX-induced neuronal damage.

Neuropharmacological review of the nootropic herb Bacopa monnieri

This review synthesizes behavioral research with neuromolecular mechanisms putatively involved with the low-toxicity cognitive enhancing action of Bacopa monnieri (BM), a medicinal Ayurvedic herb. BM is traditionally used for various ailments, but is best known as a neural tonic and memory enhancer. Numerous animal and in vitro studies have been conducted, with many evidencing potential medicinal properties. Several randomized, double-blind, placebo-controlled trials have substantiated BM's nootropic utility in humans. There is also evidence for potential attenuation of dementia, Parkinson's disease, and epilepsy. Current evidence suggests BM acts via the following mechanisms-anti-oxidant neuroprotection (via redox and enzyme induction), acetylcholinesterase inhibition and/or choline acetyltransferase activation, β-amyloid reduction, increased cerebral blood flow, and neurotransmitter modulation (acetylcholine [ACh], 5-hydroxytryptamine [5-HT], dopamine [DA]). BM appears to exhibit low toxicity in model organisms and humans; however, long-term studies of toxicity in humans have yet to be conducted. This review will integrate molecular neuroscience with behavioral research.

Na⁺-K⁺-ATPase, a potent neuroprotective modulator against Alzheimer disease

Alzheimer disease (AD) is a neurodegenerative disorder clinically characterized by progressive cognitive and memory dysfunction, which is the most common form of dementia. Although the pathogenesis of neuronal injury in AD is not clear, recent evidences suggest that Na⁺-K⁺-ATPase plays an important role in AD, and may be a potent neuroprotective modulator against AD. This review aims to provide readers with an in-depth understanding of Na⁺-K⁺-ATPase in AD through these modulations of some factors that are as follows, which leads to the change of learning and memory in the process of AD. 1. The deficiency in Na⁺, K⁺-ATPase α1, α2 and α3 isoform genes induced learning and memory deficits, and α isoform was evidently changed in AD, revealing that Na⁺, K⁺-ATPase α isoform genes may play an important role in AD. 2. Some factors, such as β-amyloid, cholinergic and oxidative stress, can modulate learning and memory in AD through the mondulation of Na⁺-K⁺-ATPase activity. 3. Some substances, such as Zn, s-Ethyl cysteine, s-propyl cysteine, citicoline, rivastigmine, Vit E, memantine, tea polyphenol, curcumin, caffeine, Alpinia galanga (L.) fractions, and Bacopa monnieri could play a role in improving memory performance and exert protective effects against AD by increasing expression or activity of Na⁺, K⁺-ATPase.