In-vitro evaluation of selected Egyptian traditional herbal medicines for treatment of Alzheimer disease

A Review on the Use of Modern Computational Methods in Alzheimer's Disease-Detection and Prediction

Discoveries in the field of medical sciences are blooming rapidly at the cost of voluminous efforts. Presently, multidisciplinary research activities have been especially contributing to catering cutting-edge solutions to critical problems in the domain of medical sciences. The modern age computing resources have proved to be a boon in this context. Effortless solutions have become a reality, and thus, the real beneficiary patients are able to enjoy improved lives. One of the most emerging problems in this context is Alzheimer's disease, an incurable neurological disorder. For this, early diagnosis is made possible with benchmark computing tools and schemes. These benchmark schemes are the results of novel research contributions being made intermittently in the timeline. In this review, an attempt is made to explore all such contributions in the past few decades. A systematic review is made by categorizing these contributions into three folds, namely, First, Second, and Third Generations. However, priority is given to the latest ones as a handful of literature reviews are already available for the classical ones. Key contributions are discussed vividly. The objectives set for this review are to bring forth the latest discoveries in computing methodologies, especially those dedicated to the diagnosis of Alzheimer's disease. A detailed timeline of the contributions is also made available. Performance plots for certain key contributions are also presented for better graphical understanding.

Treatment with Terminalia chebula Extract Reduces Insulin Resistance, Hyperglycemia and Improves SIRT1 Expression in Type 2 Diabetic Rats

BACKGROUND

Terminalia chebula Retz., Family Combretaceae (T. chebula) is one of the important plants mentioned in Ayurveda, a traditional system of medicine. The present work was designed to study the effect of the aqueous extract of T. chebula fruits in type 2 diabetic rats.

METHODS

The aqueous extract of the fruits was prepared by the double maceration technique. The extract was subjected to HPTLC analysis, which showed the presence of ellagic acid and gallic acid. Type 2 diabetes was induced in rats with a low dose of Streptozotocin (35 mg/kg) after administering a high-fat diet for fourteen days. Diabetic animals were treated with 500 and 1000 mg/kg of aqueous extract of T. chebula fruits for six weeks.

RESULTS

Diabetic rats showed a significantly (511.7 ± 17.6) (p < 0.001) high plasma glucose level compared to the normal group (106 ± 3.358). The T. chebula treatment group showed a significant (p < 0.001) reduction in plasma glucose at 500 mg/kg (394.3 ± 10.35) and 1000 mg/kg (368.6 ± 30.08) doses when compared with the diabetic control group. Treatment with aqueous extract significantly reduced lipid parameters in diabetic animals when compared to the animals in the diabetic control group. Treatment with extract at a dose of 500 mg/kg and 1000 mg/kg showed a significant reduction in AST (p < 0.01, p < 0.001) when compared with diabetic control rats. Treatment with extract significantly reduced ALT at 500 mg/kg (p < 0.05) and 1000 mg/kg (p < 0.001) doses when compared with diabetic control rats. The extract treatment improved insulin sensitivity and insulin sensitivity index (ISI) and significantly decreased HOMR-IR. Treatment with T. chebula aqueous extract at 1000 mg/kg significantly increased the level of GSH (p < 0.05) when compared to diabetic control rats. T. chebula treatment at 1000 mg/kg significantly increased levels of CAT (p < 0.01). Histopathology of pancreatic tissue revealed that the extract has a protective effect against the damage caused by hyperglycemia. Immunohistochemistry of pancreatic tissue showed increased expression of SIRT1 in diabetic animals treated with the extract.

CONCLUSIONS

The results of the present study indicate that the extract of T. chebula has significant effects in the management of type 2 diabetes.

Acetylcholinesterase inhibitory activity of Ferula plants and their potential for treatment of Alzheimer's disease

One of the current strategies in the treatment of Alzheimer's disease is using drugs with acetylcholinesterase (AChE) inhibitory property. The existence of various compounds in plants as a potential source for finding new compounds to treat Alzheimer's disease is a scientific fact. Many secondary metabolites and plant extracts have been reported with the ability to inhibit the AChE activity and improve memory and learning. These compounds can increase the concentration of acetylcholine in the brain and improve cholinergic function in individuals with Alzheimer's disease and reduce the symptoms of this neurological disorder. Plants of Ferula genus are a good source of biologically active compounds such as sesquiterpene derivatives, coumarin derivatives and sulfur-containing compounds. Numerous studies on various extracts or purified compounds of Ferula genus have shown that members of this genus have the inhibitory properties on acetylcholinesterase and can also be effective in improving Alzheimer's and amnesia. This review article summarizes studies on plants of Ferula extracts and their derived compounds to find AChE inhibitors.

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

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

A Proposed Association between Improving Energy Metabolism of HepG2 Cells by Plant Extracts and Increasing Their Sensitivity to Doxorubicin

Increasing cancer cell sensitivity to chemotherapy by amending aberrant metabolism using plant extracts represents a promising strategy to lower chemotherapy doses while retaining the same therapeutic outcome. Here, we incubated HepG2 cells with four plant extracts that were selected based on an earlier assessment of their cytotoxicity, viz asparagus, green tea, rue, and avocado, separately, before treatment with doxorubicin. MTT assays elucidated a significant decrease in doxorubicin-IC₅₀ following HepG2 incubation with each extract, albeit to a variable extent. The investigated extract's ultra-performance liquid chromatography and gas chromatography coupled with mass spectrometry (UPLC/MS and GC/MS) revealed several constituents with anticancer activity. Biochemical investigation displayed several favorable effects, including the inhibition of hypoxia-inducible factor1α (HIF1α), c-Myc, pyruvate kinase-M2 (PKM2), lactate dehydrogenase-A (LDH-A), glucose-6-phosphate dehydrogenase (G6PD), and glutaminase by asparagus and rue extracts. To less extent, HIF1α, c-Myc, PKM2, and LDH-A were partially inhibited by green tea extract, and HIF1α and glutaminase activity was inhibited by avocado oil. Undesirably, green tea extract increased glutaminase; avocado oil rose c-Myc, and both increased G6PD. In conclusion, our study confirms the potential cytotoxic effects of these plant extracts. It highlights a strong association between the ability of asparagus, green tea, rue, and avocado to sensitize HepG2 cells to doxorubicin and their power to amend cell metabolism, suggesting their use as add-on agents that might aid in clinically lowering the doxorubicin dose.

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

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

Insights into the Explicit Protective Activity of Herbals in Management of Neurodegenerative and Cerebrovascular Disorders

The longstanding progressive neurodegenerative conditions of the central nervous system arise mainly due to deterioration, degradation and eventual neuronal cell loss. As an individual ages, the irreversible neurodegenerative disorders associated with aging also begin to develop, and these have become exceedingly prominent and pose a significant burden mentally, socially and economically on both the individual and their family. These disorders express several symptoms, such as tremors, dystonia, loss of cognitive functions, impairment of motor activity leading to immobility, loss of memory and many more which worsen with time. The treatment employed in management of these debilitating neurodegenerative disorders, such as Parkinson’s disease (which mainly involves the loss of dopaminergic neurons in the nigrostriatal region), Alzheimer’s disease (which arises due to accumulation of Tau proteins causing diffusive atrophy in the brain), Huntington’s disease (which involves damage of striatal and spinal neurons, etc.), have several adverse effects, leading to exploration of several lead targets and molecules existing in herbal drugs. The current review highlights the mechanistic role of natural products in the treatment of several neurodegenerative and cerebrovascular diseases such as Parkinson’s disease, Alzheimer’s disease, ischemic stroke and depression.

Dementia in Africa: Current evidence, knowledge gaps, and future directions

In tandem with the ever-increasing aging population in low and middle-income countries, the burden of dementia is rising on the African continent. Dementia prevalence varies from 2.3% to 20.0% and incidence rates are 13.3 per 1000 person-years with increasing mortality in parts of rapidly transforming Africa. Differences in nutrition, cardiovascular factors, comorbidities, infections, mortality, and detection likely contribute to lower incidence. Alzheimer's disease, vascular dementia, and human immunodeficiency virus/acquired immunodeficiency syndrome-associated neurocognitive disorders are the most common dementia subtypes. Comprehensive longitudinal studies with robust methodology and regional coverage would provide more reliable information. The apolipoprotein E (APOE) ε4 allele is most studied but has shown differential effects within African ancestry compared to Caucasian. More candidate gene and genome-wide association studies are needed to relate to dementia phenotypes. Validated culture-sensitive cognitive tools not influenced by education and language differences are critically needed for implementation across multidisciplinary groupings such as the proposed African Dementia Consortium.

A review on Huntington protein Insight into protein aggregation and therapeutic interventions

Huntington disease (HD) is a distressing, innate neurodegenerative disease that descends from CAG repeat expansion in the huntingtin gene causing behavioral changes, motor dysfunction, and dementia in children and adults. Mutation in huntingtin (HTT) protein has been suggested to cause neuron loss in the cortex and striatum through various mechanisms including abnormal regulation of transcription, proteasomal dysfunction, post-translational modification, and other events, regulating toxicity. Pathogenesis of HD involves cleavage of the huntingtin protein followed by the neuronal accumulation of its aggregated form. Several research groups made possible efforts to reduce huntingtin gene expression, protein accumulation, and protein aggregation using inhibitors and molecular chaperones as developing drugs against HD. Herein, we review the mechanism proposed towards the formation of HTT protein aggregation and the impact of therapeutic strategies for the treatment of HD.

Teucrium polium L: An updated review of phytochemicals and biological activities

OBJECTIVE

Medicinal plants and their components are potential novel sources for developing drugs against various diseases. Teucrium polium L. (syn Teucrium capitatum L. or felty germander) from the Lamiaceae family, is widely distributed in the dry and stony places of the hills and deserts of almost all Mediterranean countries, southwestern Asia, Europe, and North Africa. Based on traditional Iranian medicine (TIM), T. polium is used for treating many diseases, including abdominal pain, indigestion, and type 2 diabetes.

MATERIALS AND METHODS

In our previous review article published in 2012 and based on 100 articles published from 1970 to 2010, the main compounds purified from T. polium were terpenes, terpenoids, and flavonoids with antioxidant, anticancer, anti-inflammatory, hypoglycemic, hepatoprotective, hypolipidemic, antibacterial, and antifungal activities.

RESULTS

In this article, the phytochemistry and pharmacological activities of the plant reported from 2011 to 2020 have been evaluated. Therefore, a search was done in the databases PubMed, Science Direct and Google Scholar, Scopus, and Web of Science with the terms "T. polium," "T. capitatum." and felty germander', which included about 100 articles published since 2011 about T. polium pharmacological activities and isolated compounds. Most studies of this review focused on the antioxidant and antidiabetic effects of the plant.

CONCLUSION

Considering the position of T. polium in folk medicine, mainly as an antidiabetic agent, purification, structural and biological characterization of the active components appears essential for effective use of the plant.

Peganum harmala enhanced GLP-1 and restored insulin signaling to alleviate AlCl3-induced Alzheimer-like pathology model

Peganum harmala (P. harmala) is a folk medicinal herb used in the Sinai Peninsula (Egypt) as a remedy for central disorders. The main constituents, harmine and harmaline, have displayed therapeutic efficacy against Alzheimer's disease (AD); however, the P. harmala potential on sensitizing central insulin to combat AD remains to be clarified. An AD-like rat model was induced by aluminum chloride (AlCl3; 50 mg/kg/day for six consecutive weeks; i.p), whereas a methanolic standardized P. harmala seed extract (187.5 mg/kg; p.o) was given to AD rats starting 2 weeks post AlCl3 exposure. Two additional groups of rats were administered either the vehicle to serve as the normal control or the vehicle + P. harmala seed extract to serve as the P. harmala control group. P. harmala enhanced cognition appraised by Y-maze and Morris water maze tests and improved histopathological structures altered by AlCl3. Additionally, it heightened the hippocampal contents of glucagon-like peptide (GLP)-1 and insulin, but abated insulin receptor substrate-1 phosphorylation at serine 307 (pS307-IRS-1). Besides, P. harmala increased phosphorylated Akt at serine 473 (pS473-Akt) and glucose transporter type (GLUT)4. The extract also curtailed the hippocampal content of beta amyloid (Aβ)42, glycogen synthase (GSK)-3β and phosphorylated tau. It also enhanced Nrf2, while reduced lipid peroxides and replenished glutathione. In conclusion, combating insulin resistance by P. harmala is a novel machinery in attenuating the insidious progression of AD by enhancing both insulin and GLP-1 trajectories in the hippocampus favoring GLUT4 production.

Redox Responsive Copolyoxalate Smart Polymers for Inflammation and Other Aging-Associated Diseases

Polyoxalate (POx) and copolyoxalate (CPOx) smart polymers are topics of interest the field of inflammation. This is due to their drug delivery ability and their potential to target reactive oxygen species (ROS) and to accommodate small molecules such as curcumin, vanilline, and p-Hydroxybenzyl alcohol. Their biocompatibility, ultra-size tunable characteristics and bioimaging features are remarkable. In this review we discuss the genesis and concept of oxylate smart polymer-based particles and a few innovative systemic delivery methods that is designed to counteract the inflammation and other aging-associated diseases (AADs). First, we introduce the ROS and its role in human physiology. Second, we discuss the polymers and methods of incorporating small molecule in oxalate backbone and its drug delivery application. Finally, we revealed some novel proof of concepts which were proven effective in disease models and discussed the challenges of oxylate polymers.

Potential therapeutic natural products against Alzheimer's disease with Reference of Acetylcholinesterase

Alzheimer's disease (AD), is the most common type of dementia primarily affecting the later years of life. Its prevalence is likely to increase in any aging population and will be a major burden on healthcare system by the mid of the century. Despite scientific and technological breakthroughs in the last 50 years, that have expanded our understanding of the disease on a system, cellular and molecular level, therapies that could stop or slow the progression of the disease are still unavailable. The Food and Drug Administration (FDA), has approved acetylcholinesterase (AChE) inhibitors (donepezil, galantamine, tacrine and rivastigmine) and glutamate receptor antagonist (memantine) for the treatment of AD. In this review we summarize the studies reporting phytocompounds and extracts from medicinal plants that show AChE inhibitory activities and could be of potential benefit in AD. Future research directions are suggested and recommendations made to expand the use of medicinal plants and their formulations to prevent, mitigate and treat AD.

Advances in biotechnology of Emblica officinalis Gaertn. syn. Phyllanthus emblica L.: a nutraceuticals-rich fruit tree with multifaceted ethnomedicinal uses

Emblica officinalis Gaertn. syn. Phyllanthus emblica L., universally known as ‘Amla’ or ‘Aonla’ or ‘Indian gooseberry’, is a popular fruit tree belonging to the family Euphorbiaceae and order Geraniales. It is said to be the very first tree that originated on earth, as claimed by age-old Indian mythology. Almost all parts of the tree i.e., root, bark, leaf, flower, fruit and seed are utilized in Ayurvedic and Unani medicinal formulations to improve the overall digestive process, decrease fever, act as a blood purifier, relieve asthma and cough, improve heart health, etc. This tree contains major secondary metabolites like emblicanin-A and emblicanin-B, and also is an affluent source of vitamin-C. Additionally, some other secondary metabolites like tannins, gallic acid, pyrogallol, and pectin are also present in significant amounts. Conventional propagation has been improved via suitable interventions of agrotechnology both in production and protection areas. However, the rate of propagation remains slower; therefore, attempts have been made for biotechnological advancements on E. officinalis. The present review makes an attempt to highlight the botanical description, geographical distribution, ethnopharmacological importance, conventional propagation and protection of this medicinal tree, describing the in vitro-based plant organ and tissue culture methods like direct and indirect organogenesis and somatic embryogenesis along with interventions of molecular marker-based biotechnology and nanotechnology. Further, the prospect of the yet-to-be-explored biotechnological methods for secondary metabolite enhancement like cell suspension, protoplast culture, genetic transformation, etc. and their potential for enhanced emblicanin production have also been discussed in this appraisal.

In silico Exploration of Bioactive Phytochemicals Against Neurodegenerative Diseases Via Inhibition of Cholinesterases

Neurodegenerative disorders are estimated to become the second leading cause of death worldwide by 2040. Despite the widespread use of diverse allopathic drugs, these brain-associated disorders can only be partially addressed and long term treatment is often linked with dependency and other unwanted side effects. Nature, believed to be an arsenal of remedies for any illness, presents an interesting avenue for the development of novel neuroprotective agents. Interestingly, inhibition of cholinesterases, involved in the breakdown of acetylcholine in the synaptic cleft, has been proposed to be neuroprotective. This review therefore aims to provide additional insight via docking studies of previously studied compounds that have shown potent activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in vitro. Indeed, the determination of potent plant-based ligands for this purpose through in silico methods enables the elimination of lengthy and costly traditional methods of drug discovery. Herein, a literature search was conducted to identify active phytochemicals which are cholinesterase inhibitors. Following which in silico docking methods were applied to obtain docking scores. Compound structures were extracted from online ZINC database and optimized using AM1 implemented in gaussian09 software. Noteworthy ligands against AChE highlighted in this study include: 19,20-dihydroervahanine A and 19, 20-dihydrotabernamine. Regarding BChE inhibition, the best ligands were found to be 8-Clavandurylkaempferol, Na-methylepipachysamine D; ebeiedinone; and dictyophlebine. Thus, ligand optimization between such phytochemicals and cholinesterases coupled with in vitro, in vivo studies and randomized clinical trials can lead to the development of novel drugs against neurodegenerative disorders.

Complementary and alternative medicine (CAM) for epilepsy treatment in the Middle East and North Africa (MENA) region

INTRODUCTION

The aim of this study is to provide the reader with a review on Complementary and Alternative Medicine (CAM) treatment in epilepsy in the Middle East and North Africa (MENA) region, to describe the extent and factors associated with its use among patients with epilepsy (PWE), and to recommend how effectively we will be able to reduce this alarming use.

MATERIAL AND METHODS

Retrospective literature search from 1945 to December 2019, regarding CAM use in the MENA region, using electronic databases (PubMed, Scopus, Google Scholar, Web of Science).

CONCLUSION

The use of CAM and consultation of traditional healers for the treatment of epilepsy has so far been widespread practice for centuries in the MENA region. Lack of health professionals and non-adherence to conventional epilepsy treatment are strongly associated with the use of CAM. Improvement in the level of knowledge of epilepsy among PWE, healthcare professionals, including traditional healers, will educate PWE and their caregivers on potentially unsafe practices and promote adherence to Antiseizure Drugs (ASDs). Additionally, randomized controlled trials are needed to study the role and value of various CAM treatment options in PWEs.

Zingiber officinale ameliorates Alzheimer's disease and Cognitive Impairments: Lessons from preclinical studies

Alzheimer's disease (AD) is a neurodegenerative condition mostly communal in people of advanced years accompanying various dysfunctionalities especially cognitive impairments. A number of cellular damages, such as amyloid-beta aggregation, tau protein hyperphosphorylation, some neurotransmitter imbalances, apoptosis, oxidative stress, and inflammatory responses are responsible for AD incidence. As a reason for inadequate efficacy, side effects, and pharmacokinetic problems of conventional drugs used for AD, the discovery of novel therapeutic agents with multi-targeted potential is desirable. Protective properties of phytochemicals combat numerous diseases and their vast acceptance and demand in human beings encouraged scientists to assess their effective activities. Zingiber officinale, gingerol, shogaol, and borneol were evaluated against memory impairments. Online databases including; Web of Science, Scopus, Embase, Pubmed, ProQuest, ScienceDirect, and Cochrane Library were searched until 3th February 2020. In vitro, in vivo, and clinical studies are included after screening their eligibility. Mostly interventive mechanisms such as; oxidative stress, neuroinflammation, and apoptosis are described. Correlation between the pathogenesis of AD and signaling pathways is explicated. Results and scores of cognition measurements are clarified due to in vivo studies and clinical trials. Some traditional aspects of consuming ginger in AD are also mentioned in the present review. In accumulation ginger and its components possess great potency for improving and abrogating memory dysfunctions but conducting further studies to evaluate their pharmacological and pharmaceutical aspects is required.

Camelina sativa Methanolic and Ethanolic Extract Potential in Alleviating Oxidative Stress, Memory Deficits, and Affective Impairments in Stress Exposure-Based Irritable Bowel Syndrome Mouse Models

Camelina sativa is mainly used as an oilseed crop; its edible oil is being also used as a traditional home remedy for the treatment of ulcers, wounds, and eye inflammations, due to the antioxidant activities. In the present study, the chemically characterized alcoholic extracts of Camelina sativa var. Madalina defatted seeds (5 g/kg body weight p.o., suspended in CMC-Na 0.1%) were administered to stress-induced animal models of irritable bowel syndrome (based on combinations of contention stress and multifactorial stress and maternal stress) and evaluated for the behavioural (short-term memory by the Y maze test, the anxious behaviour using the elevated plus maze test, and the antidepressant effect using the forced swimming test) and brain and bowel tissue oxidative status (superoxide dismutase and glutathione peroxidase enzymes activities and malondialdehyde and total soluble protein levels) improving effects. According to the chemical characterization, the extracts were rich in sinapine, glucosinolates, and flavonol glycosides. Moreover, this study showed the beneficial effects of Camelina sativa seed methanolic and ethanolic extracts on the behaviour and brain and bowel tissues oxidative stress status of stress exposure-based IBS mouse models. Despite the slight differences in the chemical composition of the methanolic and ethanolic extracts, the results suggested that the Camelina sativa extracts could reverse the short-term memory impairments caused by stress exposure and also could decrease the intensity and frequency of the anxiety and depressive-like behaviours observed in the stress-exposed animal models of IBS. Furthermore, the Camelina sativa extracts showed a significant effect on the oxidative stress markers in the brain and bowel tissues of the studied animal model by decreasing the superoxide dismutase activity and increasing the glutathione peroxidase activity. However, the results suggested that the extracts could also increase lipid peroxidation in bowel tissues. In this way, this study provides additional evidence that the administration of Camelina sativa seed alcoholic extracts could improve cognitive performances and mood and exhibit the antioxidant capacity in both the brain and bowel tissues.

Neuroprotective potential of the oxindole alkaloids isomitraphylline and mitraphylline in human neuroblastoma SH-SY5Y cells

The purified oxindole alkaloids, isomitraphylline and mitraphylline from Uncaria perrottetii, revealed their ability to break amyloid aggregates in vitro suggesting their therapeutic potentials in Alzheimer's disease (AD). Thioflavin-T assay for assessing amyloid-beta (Aβ) aggregation of these alkaloids exhibited inhibitions at 60.321% ± 2.61 (50 μM) for isomitraphylline and 43.17% ± 3.48 (50 μM) for mitraphylline. Neuroprotective effects were elaborated against Aβ-induced SH-SY5Y cells at 20 μM and 10 μM for isomitraphylline, and 20 μM for mitraphylline. In addition, both alkaloids attenuated and protected the H₂O₂-induced SH-SY5Y cell cytotoxicity at 20 μM. The intracellular ROS levels of SH-SY5Y cells from H₂O₂-induced oxidative stress were reduced at 20 μM and 10 μM, and the mitochondrial membrane potentials of Aβ-induced SH-SY5Y cells were protected at 20 μM. The overall results suggested the potentials of both alkaloids to target certain pathological biomarkers of AD and could be further investigated as therapeutic or preventive drug leads against AD.

Ayahuasca Beverages: Phytochemical Analysis and Biological Properties

Ayahuasca is a psychoactive beverage, originally consumed by indigenous Amazon tribes, of which consumption has been increasing worldwide. The aim of this study was to evaluate the phytochemical profile, as well as the antioxidant, anti-inflammatory and antimicrobial properties of decoctions of four individual plants, a commercial mixture and four mixtures of two individual plants used in the Ayahuasca preparation. For this purpose, a phytochemical characterization was performed, determining the content of flavonoids, total phenolic compounds, and analyzing the phenolic profile. Besides, 48 secondary metabolites were investigated by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS) and their concentration estimated with real standards when present. The antioxidant activity was evaluated by both the β-carotene bleaching test and DPPH free radical scavenging assay, and the anti-inflammatory activity was determined by a protein denaturation method. Finally, the antimicrobial properties were evaluated using the disc diffusion assay, resazurin microtiter method, anti-quorum sensing and anti-biofilm activity assays. The obtained results showed that, in general, the samples have a high content of phenolic compounds and flavonoids with noticeable differences, reflecting on remarkable antioxidant and anti-inflammatory activities. Significant antimicrobial properties were also observed, with emphasis on the effect of B. caapi and P. harmala on planktonic and biofilm cells of A. baumannii, inhibiting both the biofilm formation and the production of violacein pigment.

Antia, a Natural Antioxidant Product, Attenuates Cognitive Dysfunction in Streptozotocin-Induced Mouse Model of Sporadic Alzheimer's Disease by Targeting the Amyloidogenic, Inflammatory, Autophagy, and Oxidative Stress Pathways

Background

Many neurodegenerative diseases such as Alzheimer's disease are associated with oxidative stress. Therefore, antioxidant therapy has been suggested for the prevention and treatment of neurodegenerative diseases.

Objective

We investigated the ability of the antioxidant Antia to exert a protective effect against sporadic Alzheimer's disease (SAD) induced in mice. Antia is a natural product that is extracted from the edible yamabushitake mushroom, the gotsukora and kothala himbutu plants, diosgenin (an extract from wild yam tubers), and amla (Indian gooseberry) after treatment with MRN-100.

Methods

Single intracerebroventricular (ICV) injection of streptozotocin (STZ) (3 mg/kg) was used for induction of SAD in mice. Antia was injected intraperitoneally (i.p.) in 3 doses (25, 50, and 100 mg/kg/day) for 21 days. Neurobehavioral tests were conducted within 24 h after the last day of injection. Afterwards, mice were sacrificed and their hippocampi were rapidly excised, weighed, and homogenized to be used for measuring biochemical parameters.

Results

Treatment with Antia significantly improved mice performance in the Morris water maze. In addition, biochemical analysis showed that Antia exerted a protective effect for several compounds, including GSH, MDA, NF-κB, IL-6, TNF-α, and amyloid β. Further studies with western blot showed the protective effect of Antia for the JAK2/STAT3 pathway.

Conclusions

Antia exerts a significant protection against cognitive dysfunction induced by ICV-STZ injection. This effect is achieved through targeting of the amyloidogenic, inflammatory, and oxidative stress pathways. The JAK2/STAT3 pathway plays a protective role for neuroinflammatory and neurodegenerative diseases such as SAD.

In vitro evaluation of the protective effects of plant extracts against amyloid-beta peptide-induced toxicity in human neuroblastoma SH-SY5Y cells

Alzheimer's disease (AD) is the most common form of dementia and has no cure. Therapeutic strategies focusing on the reduction of oxidative stress, modulation of amyloid-beta (Aβ) toxicity and inhibition of tau protein hyperphosphorylation are warranted to avoid the development and progression of AD. The aim of this study was to screen the crude extracts (CEs) and ethyl-acetate fractions (EAFs) of Guazuma ulmifolia, Limonium brasiliense, Paullinia cupana, Poincianella pluviosa, Stryphnodendron adstringens and Trichilia catigua using preliminary in vitro bioassays (acetylcholinesterase inhibition, antioxidant activity and total polyphenol content) to select extracts/fractions and assess their protective effects against Aβ25-35 toxicity in SH-SY5Y cells. The effect of the EAF of S. adstringens on mitochondrial membrane potential, lipid peroxidation, superoxide production and mRNA expression of 10 genes related to AD was also evaluated and the electropherogram fingerprints of EAFs were established by capillary electrophoresis. Chemometric tools were used to correlate the in vitro activities of the samples with their potential to be evaluated against AD and to divide extracts/fractions into four clusters. Pretreatment with the EAFs grouped in cluster 1 (S. adstringens, P. pluviosa and L. brasiliense) protected SH-SY5Y cells from Aβ25-35-induced toxicity. The EAF of S. adstringens at 15.62 μg/mL was able completely to inhibit the mitochondrial depolarization (69%), superoxide production (49%) and Aβ25-35-induced lipid peroxidation (35%). With respect to mRNA expression, the EAF of S. adstringens also prevented the MAPT mRNA overexpression (expression ratio of 2.387x) induced by Aβ25-35, which may be related to tau protein hyperphosphorylation. This is the first time that the neuroprotective effects of these fractions have been demonstrated and that the electropherogram fingerprints for the EAFs of G. ulmifolia, L. brasiliense, P. cupana, P. pluviosa and S. adstringens have been established. The study expands knowledge of the in vitro protective effects and quality control of the evaluated fractions.

Nootropic and Anti-Alzheimer's Actions of Medicinal Plants: Molecular Insight into Therapeutic Potential to Alleviate Alzheimer's Neuropathology

Medicinal plants are the backbone of modern medicine. In recent times, there is a great urge to discover nootropic medicinal plants to reverse cognitive dysfunction owing to their less adverse effects. Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the inevitable loss of cognitive function, memory and language impairment, and behavioral disturbances, which turn into gradually more severe. Alzheimer's has no current cure, but symptomatic treatments are available and research continues. The number of patients suffering from AD continues to rise and today, there is a worldwide effort under study to find better ways to alleviate Alzheimer's pathogenesis. In this review, the nootropic and anti-Alzheimer's potentials of 6 medicinal plants (i.e., Centella asiatica, Clitoria ternatea, Crocus sativus, Terminalia chebula, Withania somnifera, and Asparagus racemosus) were explored through literature review. This appraisal focused on available information about neuroprotective and anti-Alzheimer's use of these plants and their respective bioactive compounds/metabolites and associated effects in animal models and consequences of its use in human as well as proposed molecular mechanisms. This review progresses our existing knowledge to reveal the promising linkage of traditional medicine to halt AD pathogenesis. This analysis also avowed a new insight to search the promising anti-Alzheimer's drugs.

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.

Naturally Occurring Acetylcholinesterase Inhibitors and Their Potential Use for Alzheimer's Disease Therapy

Alzheimer's disease (AD) is a main cause of dementia, accounting for up to 75% of all dementia cases. Pathophysiological processes described for AD progression involve neurons and synapses degeneration, mainly characterized by cholinergic impairment. This feature makes acetylcholinesterase inhibitors (AChEi) the main class of drugs currently used for the treatment of AD dementia phase, among which galantamine is the only naturally occurring substance. However, several plant species producing diverse classes of alkaloids, coumarins, terpenes, and polyphenols have been assessed for their anti-AChE activity, becoming potential candidates for new anti-AD drugs. Therefore, this mini-review aimed to recapitulate last decade studies on the anti-AChE activity of plant species, their respective extracts, as well as isolated compounds. The anti-AChE activity of extracts prepared from 54 plant species pertaining 29 families, as well as 36 isolated compounds were classified and discussed according to their anti-AChE pharmacological potency to highlight the most prominent ones. Besides, relevant limitations, such as proper antioxidant assessment, and scarcity of toxicological and clinical studies were also discussed in order to help researchers out with the bioprospection of potentially new AChEi.

Angelica sinensis Supercritical Fluid CO2 Extract Attenuates D-Galactose-Induced Liver and Kidney Impairment in Mice by Suppressing Oxidative Stress and Inflammation

Angelica sinensis (AS, Danggui in Chinese) is an important herbal component of various traditional formulae for the management of asthenia and its tonic effects. Although AS has been shown to ameliorate cognitive damage and nerve toxicity in D-galactose (D-gal)-elicited senescent mice brain, its effects on liver and kidney injury have not yet been explored. In this work, mice were subjected to hypodermic injection with D-gal (200 mg/kg) and orally gavaged with AS (20, 40, or 80 mg/kg) once a day for 8 successive weeks. Results revealed that AS significantly improved liver and kidney function as assessed by organ index and functional parameters. In addition, AS pretreatment effectively ameliorated the histological deterioration. AS attenuated the MDA level and markedly enhanced the activities and gene expressions of antioxidative enzymes, namely Cu, Zn-SOD, CAT, and GPx. Furthermore, AS markedly inhibited the D-gal-mediated increment of expressions of inflammatory cytokines iNOS, COX-2, IκBα, p-IκBα, and p65 and promoted the IκBα expression level in both hepatic and renal tissues. In sum, AS pretreatment could effectively guard the liver and kidney of mice from D-gal-induced injury, and the underlying mechanism was deemed to be intimately related to attenuating oxidative response and inflammatory stress.

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.

Neuroprotective effect of ipriflavone against scopolamine-induced memory impairment in rats

BACKGROUND

Alzheimer's disease is an age-related neurodegenerative disorder characterized clinically by a progressive loss of memory and cognitive functions resulting in severe dementia. Ipriflavone (IPRI) is a non-hormonal, semi-synthetic isoflavone, clinically used in some countries for the treatment and prevention of postmenopausal osteoporosis. Moreover, ipriflavone is a non-peptidomimetic small molecule AChE inhibitor with an improved bioavailability after systemic administration, due to its efficient blood-brain barrier permeability in comparison with peptidomimetic inhibitors.

OBJECTIVE

The present study aimed to evaluate the possible enhancing effects of IPRI on memory impairments caused by scopolamine administration.

METHODS

Male rats were administered IPRI (50 mg/kg, oral) 2 h before scopolamine injection (2 mg/kg, intraperitoneally injected) daily for 4 weeks. Effects of IPRI on acetylcholinesterase activity, amyloid-β precursor processing, and neuroplasticity in the rats' hippocampus were investigated.

RESULTS

Daily administration of IPRI reverted memory impairment caused by scopolamine as measured by the reduction of the escape latency. IPRI significantly alleviated the oxidative stress and restored the mRNA expression of both cAMP-response element-binding protein and brain-derived neurotrophic factor in the hippocampus. Furthermore, it significantly increased the expression of ADAM10 and ADAM17 (two putative α-secretase enzymes) and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) that associated with decreased expression of β-secretase (BACE) in the hippocampus. Finally, both the amyloid-β (Aβ) and Tau pathologies were reduced.

CONCLUSIONS

IPRI showed promising neuroprotective effects against scopolamine-induced memory dysfunction in rats. These findings contributed to the stimulation of α-secretase enzymes, the activation of MAPK/ERK1/2, and the alleviation of oxidative stress.

Possible Role of Common Spices as a Preventive and Therapeutic Agent for Alzheimer's Disease

For centuries, spices have been consumed as food additives or medicinal agents. However, there is increasing evidence indicating the plant-based foods in regular diet may lower the risk of neurodegenerative diseases including Alzheimer disease. Spices, as one of the most commonly used plant-based food additives may provide more than just flavors, but as agents that may prevent or even halt neurodegenerative processes associated with aging. In this article, we review the role and application of five commonly used dietary spices including saffron turmeric, pepper family, zingiber, and cinnamon. Besides suppressing inflammatory pathways, these spices may act as antioxidant and inhibit acetyl cholinesterase and amyloid β aggregation. We summarized how spice-derived nutraceuticals mediate such different effects and what their molecular targets might be. Finally, some directions for future research are briefly discussed.

A Review on Potential Mechanisms of Terminalia chebula in Alzheimer's Disease

The current management of Alzheimer's disease (AD) focuses on acetylcholinesterase inhibitors (AChEIs) and NMDA receptor antagonists, although outcomes are not completely favorable. Hence, novel agents found in herbal plants are gaining attention as possible therapeutic alternatives. The Terminalia chebula (Family: Combretaceae) is a medicinal plant with a wide spectrum of medicinal properties and is reported to contain various biochemicals such as hydrolysable tannins, phenolic compounds, and flavonoids, so it may prove to be a good therapeutic alternative. In this research, we reviewed published scientific literature found in various databases: PubMed, Science Direct, Scopus, Web of Science, Scirus, and Google Scholar, with the keywords: T. chebula, AD, neuroprotection, medicinal plant, antioxidant, ellagitannin, gallotannin, gallic acid, chebulagic acid, and chebulinic acid. This review shows that T. chebula extracts and its constituents have AChEI and antioxidant and anti-inflammatory effects, all of which are currently relevant to the treatment of Alzheimer's disease.

Influence of asafoetida on prevention and treatment of memory impairment induced by d-galactose and NaNO2 in mice

In Iranian traditional medicine, asafoetida is introduced as a valuable remedy for nervous disorders. Dementia was induced by injection of d-galactose and NaNO2 for 60 consecutive days. Animals were divided into normal control (NC), dementia control (DC), dementia prophylactic (DP), and dementia treated (DT). The learning and memory functions were examined by 1-way active and passive avoidance tests, using a shuttle box device. Avoidance response in training tests and 1 and 3 weeks later was significantly increased in NC, DP, and DT groups compared to the DC group. Step through latency in all groups was significantly greater than the DC group. Total time spent in light room, which shows the memory retention ability, in DP, NC, and DT was significantly greater than the DC group. Our findings indicate that asafoetida could prevent and treat amnesia. These beneficial effects maybe related to some constituent's effectiveness such as ferulic acid and umbelliferone.

Recent updates in the treatment of neurodegenerative disorders using natural compounds

Neurodegenerative diseases are characterized by protein aggregates and inflammation as well as oxidative stress in the central nervous system (CNS). Multiple biological processes are linked to neurodegenerative diseases such as depletion or insufficient synthesis of neurotransmitters, oxidative stress, abnormal ubiquitination. Furthermore, damaging of blood brain barrier (BBB) in the CNS also leads to various CNS-related diseases. Even though synthetic drugs are used for the management of Alzheimer's disease, Parkinson's disease, autism, and many other chronic illnesses, they are not without side effects. The attentions of researchers have been inclined towards the phytochemicals, many of which have minimal side effects. Phytochemicals are promising therapeutic agents because many phytochemicals have anti-inflammatory, antioxidative as well as anticholinesterase activities. Various drugs of either synthetic or natural origin applied in the treatment of brain disorders need to cross the BBB before they can be used. This paper covers various researches related to phytochemicals used in the management of neurodegenerative disorders.

Pharmacogenomics of Alzheimer's disease: novel therapeutic strategies for drug development

Alzheimer's disease (AD) is a major problem of health and disability, with a relevant economic impact on our society. Despite important advances in pathogenesis, diagnosis, and treatment, its primary causes still remain elusive, accurate biomarkers are not well characterized, and the available pharmacological treatments are not cost-effective. As a complex disorder, AD is a polygenic and multifactorial clinical entity in which hundreds of defective genes distributed across the human genome may contribute to its pathogenesis. Diverse environmental factors, cerebrovascular dysfunction, and epigenetic phenomena, together with structural and functional genomic dysfunctions, lead to amyloid deposition, neurofibrillary tangle formation, and premature neuronal death, the major neuropathological hallmarks of AD. Future perspectives for the global management of AD predict that genomics and proteomics may help in the search for reliable biomarkers. In practical terms, the therapeutic response to conventional drugs (cholinesterase inhibitors, multifactorial strategies) is genotype-specific. Genomic factors potentially involved in AD pharmacogenomics include at least five categories of gene clusters: (1) genes associated with disease pathogenesis; (2) genes associated with the mechanism of action of drugs; (3) genes associated with drug metabolism (phase I and II reactions); (4) genes associated with drug transporters; and (5) pleiotropic genes involved in multifaceted cascades and metabolic reactions. The implementation of pharmacogenomic strategies will contribute to optimize drug development and therapeutics in AD and related disorders.