A review on ferulic acid and analogs based scaffolds for the management of Alzheimer's disease

Mitigating effect of ferulic acid on di-(2-ethylhexyl) phthalate-induced neurocognitive dysfunction in male rats with a comprehensive in silico survey

Di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate threatening public health-induced neurotoxicity. This neurotoxicity is associated with behavioral and biochemical deficits in male rats. Our study investigated the neuroprotective effect of ferulic acid (FA) on male rats exposed to DEHP. Thirty-two male Wistar rats were assigned to four groups. Group I control rats received corn oil, group II intoxicated rats received 300 mg/kg of DEHP, group III received 300 mg/kg of DEHP + 50 mg/kg of FA, and group IV received 50 mg/kg of FA, all agents administrated daily per os for 30 days. Anxiety-like behavior, spatial working memory, and recognition memory were assessed. Also, brain oxidative stress biomarkers, including brain malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NO), superoxide dismutase (SOD), brain-derived neurotrophic factor (BDNF) as well as heme oxygenase-1 (HO-1) were measured. Moreover, brain histopathology examinations associated with immunohistochemistry determination of brain caspase-3 were also evaluated. Furthermore, docking simulation was adapted to understand the inhibitory role of FA on caspase-3 and NO synthase. Compared to DEHP-intoxicated rats, FA-treated rats displayed improved cognitive memory associated with a reduced anxious state. Also, the redox state was maintained with increased BNDF levels. These changes were confirmed by restoring the normal architecture of brain tissue and a decrement in the immunohistochemistry caspase-3. In conclusion, FA has potent antioxidant and antiapoptotic properties that confirm the neuroprotective activity of FA, with a possible prospect for its therapeutic capabilities and nutritional supplement value.

Design, Synthesis, and Biological Evaluation of Ferulic Acid Template-Based Novel Multifunctional Ligands Targeting NLRP3 Inflammasome for the Management of Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia, which arises due to low levels of acetyl and butyrylcholines, an increase in oxidative stress, inflammation, metal dyshomeostasis, Aβ and tau aggregations. The currently available drugs for AD treatment can provide only symptomatic relief without interfering with pathological hallmarks of the disease. In our ongoing efforts to develop naturally inspired novel multifunctional molecules for AD, systematic SAR studies on EJMC-4e were caried out to improve its multifunctional properties. The rigorous medicinal efforts led to the development of 12o, which displayed a 15-fold enhancement in antioxidant properties and a 2-fold increase in the activity against AChE and BChE over EJMC-4e. Molecular docking and dynamics studies revealed the binding sites and stability of the complex of 12o with AChE and BChE. The PAMPA-BBB assay clearly demonstrated that 12o can easily cross the blood-brain barrier. Interestingly, 12o also expresses promising metal chelation activity, while EJMC-4e was found to be devoid of this property. Further, 12o inhibited metal-induced or self Aβ1-42 aggregation. Observing the neuroprotection ability of 12o against H2O2-induced oxidative stress in the PC-12 cell line is noteworthy. Furthermore, 12o also inhibited NLRP3 inflammasome activation and attenuated mitochondrial-induced ROS and MMP damage caused by LPS and ATP in HMC-3 cells. In addition, 12o is able to effectively reduce mitochondrial and cellular oxidative stress in the AD Drosophila model. Finally, 12o could reverse memory impairment in the scopolamine-induced AD mice model, as evident through in vivo and ex vivo studies. These findings suggest that this compound may act as a promising candidate for further improvement in the management of AD.

Ferulic acid's therapeutic odyssey: nano formulations, pre-clinical investigations, and patent perspective

INTRODUCTION

Ferulic acid (FA) is a phenolic phytochemical that has garnered the attention of the research community due to its abundant availability in nature. It is a compound that has been explored for its multifaceted therapeutic potential and benefits in modern and contemporary healthcare.

AREAS COVERED

This review furnishes a compilation of the molecular mechanisms underlying the anti-diabetic, anticancer, antioxidant, and anti-inflammatory effects of FA. We also aim to excavate an in-depth analysis of the role of nanoformulations to achieve release control, reduce toxicity, and deliver FA at specified target sites. To corroborate the safety and efficacy of FA, a multitude of pre-clinical studies have also been conducted by researchers and have been discussed comprehensively in this review. The various patented innovations and newer paradigms pertaining to FA have also been presented.

EXPERT OPINION

Enormous research has been conducted and should still be continued to find the best possible novel drug delivery system for FA delivery. The utilization of nanocarriers and nanoformulations has intrigued the scientists for delivery of FA, but before that, it is necessary to shed light upon toxicity, safety, and regulatory concerns of FA.

Recent approaches in regenerative medicine in the fight against neurodegenerative disease

Neurodegenerative diseases arise due to slow and gradual loss of structure and/or function of neurons and glial cells and cause different degrees of loss of cognition abilities and sensation. The little success in developing effective treatments imposes a high and regressive economic impact on society, patients and their families. In recent years, regenerative medicine has provided a great opportunity to research new innovative strategies with strong potential to treatleva these diseases. These effects are due to the ability of suitable cells and biomaterials to regenerate damaged nerves with differentiated cells, creating an appropriate environment for recovering or preserving existing healthy neurons and glial cells from destruction and damage. Ultimately, a better understanding and thus a further investigation of stem cell technology, tissue engineering, gene therapy, and exosomes allows progress towards practical and effective treatments for neurodegenerative diseases. Therefore, in this review, advances currently being developed in regenerative medicine using animal models and human clinical trials in neurological disorders are summarized.

Diet-gut microbiome interaction and ferulic acid bioavailability: implications on neurodegenerative disorders

PURPOSE OF THE REVIEW

Ferulic acid (FA), which occurs naturally as the feruloylated sugar ester in grains, fruits, and vegetables, is critical for combating oxidative stress and alleviating neurodegenerative diseases resulting from free radical-generated protein aggregates in brain cells. However, FA cannot be absorbed in conjugated form. Therefore, strategies to improve the bioavailability of FA are gaining more importance. Ferulic acid esterases (FAE) of the gut microbiota are critical enzymes that facilitate FA release from feruloylated sugar ester conjugates and influence systemic health. This review provides insight into a nutrition-based approach to preventing neurodegenerative disorders such as Alzheimer's and Parkinson's by altering the diversity of FAE-producing gut microbiota.

RECENT FINDINGS

The human gut is a niche for a highly dense microbial population. Nutrient components and the quality of food shape the gut microbiota. Microbiota-diet-host interaction primarily involves an array of enzymes that hydrolyse complex polysaccharides and release covalently attached moieties, thereby increasing their bio-accessibility. Moreover, genes encoding polysaccharide degrading enzymes are substrate inducible, giving selective microorganisms a competitive advantage in scavenging nutrients. Nutraceutical therapy using specific food components holds promise as a prophylactic agent and as an adjunctive treatment strategy in neurotherapeutics, as it results in upregulation of polysaccharide utilisation loci containing fae genes in the gut microbiota, thereby increasing the release of FA and other antioxidant molecules and combat neurodegenerative processes.

Simple phenylpropanoids: recent advances in biological activities, biosynthetic pathways, and microbial production

Covering: 2000 to 2023Simple phenylpropanoids are a large group of natural products with primary C6-C3 skeletons. They are not only important biomolecules for plant growth but also crucial chemicals for high-value industries, including fragrances, nutraceuticals, biomaterials, and pharmaceuticals. However, with the growing global demand for simple phenylpropanoids, direct plant extraction or chemical synthesis often struggles to meet current needs in terms of yield, titre, cost, and environmental impact. Benefiting from the rapid development of metabolic engineering and synthetic biology, microbial production of natural products from inexpensive and renewable sources provides a feasible solution for sustainable supply. This review outlines the biological activities of simple phenylpropanoids, compares their biosynthetic pathways in different species (plants, bacteria, and fungi), and summarises key research on the microbial production of simple phenylpropanoids over the last decade, with a focus on engineering strategies that seem to hold most potential for further development. Moreover, constructive solutions to the current challenges and future perspectives for industrial production of phenylpropanoids are presented.

Carbamate as a potential anti-Alzheimer's pharmacophore: A review

Alzheimer's disease (AD) is a progressive age-related neurodegenerative brain disorder, which leads to loss of memory and other cognitive dysfunction. The underlying mechanisms of AD pathogenesis are very complex and still not fully explored. Cholinergic neuronal loss, accumulation of amyloid plaque, metal ions dyshomeostasis, tau hyperphosphorylation, oxidative stress, neuroinflammation, and mitochondrial dysfunction are major hallmarks of AD. The current treatment options for AD are acetylcholinesterase inhibitors (donepezil, rivastigmine, and galantamine) and NMDA receptor antagonists (memantine). These FDA-approved drugs mainly provide symptomatic relief without addressing the pathological aspects of disease progression. So, there is an urgent need for novel drug development that not only addresses the basic mechanisms of the disease but also shows the neuroprotective property. Various research groups across the globe are working on the development of multifunctional agents for AD amelioration using different core scaffolds for their design, and carbamate is among them. Rivastigmine was the first carbamate drug investigated for AD management. The carbamate fragment, a core scaffold of rivastigmine, act as a potential inhibitor of acetylcholinesterase. In this review, we summarize the last 10 years of research conducted on the modification of carbamate with different substituents which primarily target ChE inhibition, reduce oxidative stress, and modulate Aβ aggregation.

Berberine derivatives as inhibitors of acetylcholinesterase: A systematic review

Alzheimer's disease (AD) is a chronic age-related neurodegenerative brain disorder characterized by the impairment of memory accompanied by worsening of thinking ability of an individual. The exact pathophysiology of AD is not fully understood. However low level of the neurotransmitter named acetylcholine (ACh), aggregation of Aβ peptide into toxic Aβ plaque, hyperphosphorylation of tau, bio-metal imbalance, and oxidative stress are the main hallmarks of this disease. Due to the complex pathophysiology of AD, no specific treatment is available in the market, and treatment is only limited to the symptomatic relief. So, there is an urgent need for the development of new drug candidate, which can have disease-modifying effect and improve learning and memory in AD patient. Therefore, berberine-based multifunction compounds with potential cholinesterase inhibitory properties were reviewed in this article. Structure-activity relationship (SAR) and biological activity provide highlights on the new derivatives used for the management of AD.

Tryptamine: A privileged scaffold for the management of Alzheimer's disease

Alzheimer's disease (AD) is a chronic and irreversible neurodegenerative disease associated with aging. It is characterized by the progressive loss of memory and other cognitive functions. Although the exact etiology of AD is not well explored, several factors, such as the deposition of amyloid-β (Aβ) plaques, hyperphosphorylation of tau protein, presence of low levels of acetylcholine, and generation of oxidative stress, are key mediators in the progression of AD. Currently, the clinical treatment options for AD are limited and are based on cholinesterase (ChE) inhibitors (e.g., donepezil, rivastigmine, and galantamine), N-methyl- d-aspartic acid receptor antagonists (e.g., memantine), and the recently approved Aβ modulator (e.g., aducanumab). Tryptamine (2-(1H-indol-3-yl)ethan-1-amine) is a small molecule that contains an indole nucleus and an ethylamine side chain. It is also the active metabolite of tryptophan. It possesses a wide range of biological activities related to neurodegenerative disorders, such as ChE inhibition, Aβ aggregation inhibition, antioxidant effects, monoamine-oxidase inhibition, and neuroprotection. Several tryptamine-based hybrid analogs are currently being investigated as multifunctional agents for the development of novel hybrids for AD treatment. Thus, this review article aims to provide in-depth insights into the research progress and strategies for designing multifunctional agents used in Alzheimer's therapy.

Synthesis of lipoic acid ferulate and evaluation of its ability to preserve fish oil from oxidation during accelerated storage

Lipoic acid ferulate (LAF) was synthesized and its anti-free radical ability in vitro was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylbenzothiazoline-6-sulfonicacid) (ABTS) assays. Protective effects of LAF in stabilizing fish oil were tested, compared to antioxidants such as lipoic acid, ferulic acid and tert-butylhydroxyquinone (TBHQ) by measuring peroxide values, thiobarbituric acid reactants, p-anisidine values, nuclear magnetic resonance (NMR) spectra and gas chromatography-mass spectrometry (GC-MS) spectra of fish oil during accelerated storage (12 days, 80 °C). The inhibitory effect of these antioxidants on fish oil oxidation followed the order TBHQ ≧ LAF > ferulic acid > lipoic acid. In addition, the omega-3 polyunsaturated fatty acids were the first to be oxidized. The formation of oxidation products followed a first-order kinetic model, and the addition of LAF effectively reduced the reaction rate constants. Therefore, LAF can effectively slow down the formation of oxidative products and prolong the shelf life of fish oil.

Molecular mechanisms underlying cyclophosphamide-induced cognitive impairment and strategies for neuroprotection in preclinical models

Cyclophosphamide has drastically enhanced the expectancy and quality of life of cancer patients. However, it is accompanied by diverse neurological complications which are considered a dose-limiting adverse effect. Neurotoxicity caused by cyclophosphamide can manifest in numerous manners including anxiety, depression, motor dysfunction and cognitive deficits. This review article offers an overview on cyclophosphamide-induced neurotoxicity, providing a unified point of view on the possible underlying molecular mechanisms including oxidative brain damage, neuroinflammation, apoptotic neuronal cell death as well as disruption of the balance of brain neurotransmitters and neurotrophic factors. Besides, this review sheds light on the promising protective agents that have been investigated using preclinical animal models as well as their biological targets and protection mechanisms. Despite promising results in experimental models, none of these agents has been studied in clinical trials. Thus, there is lack of evidence to advocate the use of any neuroprotective agent in the clinical setting. Furthermore, none of the protective agents has been evaluated for its effect on the anticancer activity of cyclophosphamide in tumor-bearing animals. Therefore, there is a great necessity for adequate well-designed clinical studies for evaluation of the therapeutic values of these candidates. Conclusively, this review summarizes the molecular mechanisms accounting for cyclophosphamide-induced neurotoxicity together with the potential protective strategies seeking for downgrading this neurological complication, thus enhancing the quality of life and well-being of cancer patients treated with cyclophosphamide.

Pomegranate: A Source of Multifunctional Bioactive Compounds Potentially Beneficial in Alzheimer's Disease

Pomegranate fruit (PF) is a fruit rich in nutraceuticals. Nonedible parts of the fruit, especially peels, contain high amounts of bioactive components that have been largely used in traditional medicine, such as the Chinese, Unani, and Ayurvedic ones, for treating several diseases. Polyphenols such as anthocyanins, tannins, flavonoids, phenolic acids, and lignans are the major bioactive molecules present in PF. Therefore, PF is considered a source of natural multifunctional agents that exert simultaneously antioxidant, anti-inflammatory, antitumor, antidiabetic, cardiovascular, and neuroprotective activities. Recently, several studies have reported that the nutraceuticals contained in PF (seed, peel, and juice) have a potential beneficial role in Alzheimer's disease (AD). Research suggests that the neuroprotective effect of PF is mostly due to its potent antioxidant and anti-inflammatory activities which contribute to attenuate the neuroinflammation associated with AD. Despite the numerous works conducted on PF, to date the mechanism by which PF acts in combatting AD is not completely known. Here, we summarize all the recent findings (in vitro and in vivo studies) related to the positive effects that PF and its bioactive components can have in the neurodegeneration processes occurring during AD. Moreover, considering the high biotransformation characteristics of the nutraceuticals present in PF, we propose to consider the chemical structure of its active metabolites as a source of inspiration to design new molecules with the same beneficial effects but less prone to be affected by the metabolic degradation process.

Effects of Danggui-Shaoyao-San on central neuroendocrine and pharmacokinetics in female ovariectomized rats

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine formula Danggui-Shaoyao-San (DSS) has been reported to have estrogen-like effects and therapeutic effects on the symptoms of Alzheimer's disease (AD).

AIM OF THE STUDY

To explore whether the central oxytocin and neuroendocrine system is involved in the modulating effects of DSS on the cognition and neuropsychiatric hebaviors in female AD rats, and to investigate the pharmacokinetics of paeoniflorin and ferulic acid in female AD rats with DSS treatment.

MATERIAL AND METHODS

DSS (1.2, 3.2, 8.6g/kg/day) was orally administered to ovariectomized (OVX) rats, and saline was orally administered to sham operation rats as control group. The Morris water maze test, novel object recognition test, and passive avoidance test were conducted for evaluation of learning and memory abilities, while elevated plus maze test and forced swim test were performed to assess anxiety- and depressive-like behaviors. ELISA kits were used to detect the levels of estrogen (E), estrogen receptor α (ERα), oxytocin (OT), oxytocin receptor (OTR), acetylcholine (Ach), acetylcholin esterase (AchE), and choline acetyl transferase (ChAT) in the cortex. The concentrations of Ach, glutamate (Glu), γ-aminobutyric acid (GABA), 5-hydroxytryptamine (5-HT), norepinephrine (NE) and dopamine (DA) in the hippocampus were assessed by HPLC-MS. The changes of neuronal morphology in the hippocampus were observed by Nissl staining. The pharmacokinetics of paeoniflorin and ferulic acid in OVX rats with DSS treatment were studied by HPLC.

RESULTS

In the Morris water maze test, novel object recognition test, and passive avoidance test, OVX rats showed cognitive impairment. In the elevated plus maze test and forced swim test, the anxiety- and depressive-like behaviors of OVX rats were significant as compared to the control group. Treatment of DSS significantly imporved the cognitive deficits, and ameliorated anxiety- and depressive-like behaviors of OVX rats. The expression of E, ERα, OT, OTR, AchE and ChAT in the cortex of model group were significantly decreased, and DSS significantly reversed these changes. The concentrations of Ach, Glu, GABA, 5-HT and NE in the hippocampus of OVX rats were significantly decreased, whereas DSS significantly increased the levels of Ach, Glu, GABA, 5-HT and NE. There was no significant difference in the concentration of DA in the hippocampus among groups. Degenerating neurons in the hippocampal CA3 region were observed in OVX rats, and the number of neurons was decreased. DSS treatment reduced the degenerating neurons, and incresed the number of neurons. The MRT (0 - ∞), AUC (0 - ∞), Cmax and t1/2z values of paeoniflorin, and the AUC _0-∞ and C_max value of ferulic acid were higher in DSS-treated OVX rats than those in the DSS-treated control rats.

CONCLUSIONS

DSS improves the learning and memory ability, and attenuates anxiety- and depressive-like behaviors of OVX rats. The mechanism may be through increasing estrogen, reducing cholinergic damage, and modulating neurotransmitters. The increase in absorption and elimination time of paeoniflorin and ferulic acid in OVX rats may enhance the efficacy of DSS.

Ferulic acid-loaded polymeric nanoparticles prepared from nano-emulsion templates facilitate internalisation across the blood-brain barrier in model membranes

A hydroxycinnamic acid derivative, namely ferulic acid (FA) has been successfully encapsulated in polymeric nanoparticles (NPs) based on poly(lactic-co-glycolic acid) (PLGA). FA-loaded polymeric NPs were prepared from O/W nano-emulsion templates using the phase inversion composition (PIC) low-energy emulsification method. The obtained PLGA NPs exhibited high colloidal stability, good drug-loading capacity, and particle hydrodynamic diameters in the range of 74 to 117 nm, depending on the FA concentration used. In vitro drug release studies confirmed a diffusion-controlled mechanism through which the amount of released FA reached a plateau at 60% after 6 hours-incubation. Five kinetic models were used to fit the FA release data as a function of time. The Weibull distribution and Korsmeyer-Peppas equation models provided the best fit to our experimental data and suggested quasi-Fickian diffusion behaviour. Moderate dose-response antioxidant and radical scavenging activities of FA-loaded PLGA NPs were demonstrated using the DPPH˙ assay achieving inhibition activities close to 60 and 40%, respectively. Cell culture studies confirmed that FA-loaded NPs were not toxic according to the MTT colorimetric assay, were able to internalise efficiently SH-SY5Y neuronal cells and supressed the intracellular ROS-level induced by H₂O₂ leading to 52% and 24.7% of cellular viability at 0.082 and 0.041 mg mL^-1, respectively. The permeability of the NPs through the blood brain barrier was tested with an in vitro organ-on-a-chip model to evaluate the ability of the FA-loaded PLGA and non-loaded PLGA NPs to penetrate to the brain. NPs were able to penetrate the barrier, but permeability decreased when FA was loaded. These results are promising for the use of loaded PLGA NPs for the management of neurological diseases.

Response Surface Optimization of Extraction Conditions for the Active Components with High Acetylcholinesterase Inhibitory Activity and Identification of Key Metabolites from Acer truncatum Seed Oil Residue

The State Council of China has called for the comprehensive development and utilization of Acer truncatum resources. However, research on one of its by-products, namely seed oil residue (ASR), from seed oil extraction is seriously insufficient, resulting in a waste of these precious resources. We aimed to optimize the conditions of ultrasound-assisted extraction (UAE) using a response surface methodology to obtain high acetylcholinesterase (AChE) inhibitory components from ASR and to tentatively identify the active metabolites in ASR using non-targeted metabolomics. Based on the results of the independent variables test, the interaction effects of three key extracting variables, including methanol concentration, ultrasonic time, and material-to-liquid ratio, were further investigated using the Box-Behnken design (BBD) to obtain prior active components with high AChE inhibitory activity. UPLC-QTOF-MS combined with a multivariate method was used to analyze the metabolites in ASR and investigate the causes of activity differences. Based on the current study, the optimal conditions for UAE were as follows: methanol concentration of 85.06%, ultrasonic time of 39.1 min, and material-to-liquid ratio of 1.06:10 (g/mL). Under these optimal conditions, the obtained extracts show strong inhibitions against AChE with half maximal inhibitory concentration (IC₅₀) values ranging from 0.375 to 0.459 µg/mL according to an Ellman's method evaluation. Furthermore, 55 metabolites were identified from the ASR extracted using methanol in different concentrations, and 9 biomarkers were subsequently identified as potential compounds responsible for the observed AChE inhibition. The active extracts have potential to be used for the development of functional foods with positive effects on Alzheimer's disease owing to their high AChE inhibition activity. Altogether, this study provides insights into promoting the comprehensive utilization of A. truncatum resources.

Therapeutic Potential of Phenolic Compounds in Medicinal Plants-Natural Health Products for Human Health

Phenolic compounds and flavonoids are potential substitutes for bioactive agents in pharmaceutical and medicinal sections to promote human health and prevent and cure different diseases. The most common flavonoids found in nature are anthocyanins, flavones, flavanones, flavonols, flavanonols, isoflavones, and other sub-classes. The impacts of plant flavonoids and other phenolics on human health promoting and diseases curing and preventing are antioxidant effects, antibacterial impacts, cardioprotective effects, anticancer impacts, immune system promoting, anti-inflammatory effects, and skin protective effects from UV radiation. This work aims to provide an overview of phenolic compounds and flavonoids as potential and important sources of pharmaceutical and medical application according to recently published studies, as well as some interesting directions for future research. The keyword searches for flavonoids, phenolics, isoflavones, tannins, coumarins, lignans, quinones, xanthones, curcuminoids, stilbenes, cucurmin, phenylethanoids, and secoiridoids medicinal plant were performed by using Web of Science, Scopus, Google scholar, and PubMed. Phenolic acids contain a carboxylic acid group in addition to the basic phenolic structure and are mainly divided into hydroxybenzoic and hydroxycinnamic acids. Hydroxybenzoic acids are based on a C6-C1 skeleton and are often found bound to small organic acids, glycosyl moieties, or cell structural components. Common hydroxybenzoic acids include gallic, syringic, protocatechuic, p-hydroxybenzoic, vanillic, gentistic, and salicylic acids. Hydroxycinnamic acids are based on a C6-C3 skeleton and are also often bound to other molecules such as quinic acid and glucose. The main hydroxycinnamic acids are caffeic, p-coumaric, ferulic, and sinapic acids.

Sarcococca saligna ameliorated D-galactose induced neurodegeneration through repression of neurodegenerative and oxidative stress biomarkers

Sarcococca saligna is a valuable source of bioactive secondary metabolites exhibiting antioxidant, anti-inflammatory and acetylcholinesterase inhibitory activities. The study was intended to explore the therapeutic pursuits of S. saligna in amelioration of cognitive and motor dysfunctions induced by D-galactose and linked mechanistic pathways. Alzheimer's disease model was prepared by administration of D-galactose subcutaneous injection100 mg/kg and it was treated with rivastigmine (100 mg/kg, orally) and plant extract for 42 days. Cognitive and motor functions were evaluated by behavioral tasks and oxidative stress biomarkers. Level of acetylcholinesterase, reduced level of glutathione, protein and nitrite level, and brain neurotransmitters were analyzed in brain homogenate. The level of apoptosis regulator Bcl-2, Caspases 3 and heat shock protein HSP-70 in brain homogenates were analyzed by ELISA and colorimetric method, respectively. AChE, IL-1β, TNF-α, IL-1α and β secretase expressions were analyzed by RT-PCR. S. saligna dose dependently suppressed the neurodegenerative effects of D-galactose induced behavioral and biochemical impairments through modulation of antioxidant enzymes and acetylcholinesterase inhibition. S. saligna markedly (P < 0.05) ameliorated the level of brain neurotransmitters, Bcl-2, HSP-70 and Caspases-3 level. S. saligna at 500-1000 mg/kg considerably recovered the mRNA expression of neurodegenerative and neuro-inflammatory biomarkers, also evident from histopathological analysis. These findings suggest that S. saligna could be applicable in cure of Alzheimer's disease.

Click-designed vanilloid-triazole conjugates as dual inhibitors of AChE and Aβ aggregation

Based on their reported neuroprotective properties, vanilloids provide a good starting point for the synthesis of anti-Alzheimer's disease (AD) agents. In this context, nine new 1,2,3-triazole conjugates of vanilloids were synthesized via click chemistry. The compounds were tested for their effect on acetylcholine esterase (AChE) and amyloid-beta peptide (Aβ) aggregation. The triazole esters (E)-(1-(4-hydroxy-3-methoxybenzyl)-1H-1,2,3-triazol-4-yl)methyl 3-(4-hydroxy-3 methoxyphenyl)acrylate 9 and (1-(4-hydroxy-3-methoxybenzyl)-1H-1,2,3-triazol-4-yl)methyl-4-hydroxy-3-methoxybenzoate 8 displayed dual inhibitory activity for AChE and Aβ aggregation with IC50 values of 0.47/0.31 μM and 1.2/0.95 μM, respectively, as compared to donepezil (0.27 μM) and tacrine (0.41 μM), respectively. The results showed that the triazole ester moiety is more favorable for the activity than the triazole ether moiety. This could be attributed to the longer length of the spacer between the two vanillyl moieties in the triazole esters. Furthermore, the binding affinities and modes of the triazole esters 9 and 8 were examined against AChE and Aβ utilizing a combination of docking predictions and molecular dynamics (MD) simulations. Docking computations revealed promising binding affinity of triazole esters 9 and 8 as potential AChE, Aβ40, and Aβ42 inhibitors with docking scores of -10.4 and -9.4 kcal mol-1, -5.8 and -4.7 kcal mol-1, and -3.3 and -2.9 kcal mol-1, respectively. The stability and binding energies of triazole esters 9 and 8 complexed with AChE, Aβ40, and Aβ42 were measured and compared to donepezil and tacrine over 100 ns MD simulations. According to the estimated binding energies, compounds 9 and 8 displayed good binding affinities with AChE, Aβ42, and Aβ40 with average ΔG binding values of -32.9 and -31.8 kcal mol-1, -12.0 and -10.5 kcal mol-1, and -20.4 and -16.6 kcal mol-1, respectively. Post-MD analyses demonstrated high steadiness for compounds 9 and 8 with AChE and Aβ during the 100 ns MD course. This work suggests the triazole conjugate of vanilloids as a promising skeleton for developing multi-target potential AD therapeutics.

Comparison of Yizhiqingxin formula extraction methods and their pharmacodynamic differences

Objectives

This study compared different extraction methods of Yizhiqingxin formula (YQF) and its neuroprotective effects based on pharmacodynamic indices such as learning and memory ability, brain tissue histopathology and morphology, and inflammatory factor expression in a mouse model of Alzheimer's disease (AD).

Methods

The pharmaceutical components of YQF were extracted using three extraction processes, and the components were analyzed by high performance liquid chromatography. Donepezil hydrochloride was used as a positive control drug. Fifty 7-8-month-old 3 × Tg AD mice were randomly divided into three YQF groups (YQF-1, YQF-2, and YQF-3), a donepezil group, and a model group. Ten age-matched C57/BL6 mice were used as normal controls. YQF and Donepezil were administered by gavage at a clinically equivalent dose of 2.6 and 1.3 mg⋅kg^-1⋅d^-1, respectively, with a gavage volume of 0.1 ml/10 g. Control and model groups received equal volumes of distilled water by gavage. After 2 months, the efficacy was evaluated using behavioral experiments, histopathology, immunohistochemistry, and serum assays.

Results

The main components in YQF are ginsenoside Re, ginsenoside Rg1, ginsenoside Rb1, epiberberine, coptisine chloride, palmatine, berberine, and ferulic acid. YQF-3 (alcohol extraction) has the highest content of active compounds, followed by YQF-2 (water extraction and alcohol precipitation method). Compared to the model group, the three YQF groups showed alleviated histopathological changes and improved spatial learning and memory, with the effect in YQF-2 being the most significant. YQF showed protection of hippocampal neurons, most significantly in the YQF-1 group. YQF significantly reduced Aβ pathology and tau hyperphosphorylation, decreased expressions of serum pro-inflammatory factors interleukin-2 and interleukin-6 as well as serum chemokines MCP-1 and MIG.

Conclusion

YQF prepared by three different processes showed differences in pharmacodynamics in an AD mouse model. YQF-2 was significantly better than the other extraction processes in improving memory.

Neuroprotective potential of ferulic acid against cyclophosphamide-induced neuroinflammation and behavioral changes

In the present study, ferulic acid (FRA) has been explored for possible neuroprotective effects against cyclophosphamide (CP)-induced neurotoxicity in the Swiss Albino mice. Animals were divided into five groups and treated with FRA for fourteen days and a single dose of CP was administered on the seventh day. Animals were subjected to neurobehavioral tests such as the forced swim test and Morris Water Maze test. On day fifteenth, the brain was removed and used for biochemical analysis. The outcome of the study showed that CP administration induced significant neurotoxicity in the form of depression, anxiety, and cognitive dysfunction. Cyclophosphamide administration also reduced the activity of antioxidant enzymes, reduced the level of neurotransmitters (i.e., dopamine, 5-HT, and BDNF), anti-inflammatory cytokines (IL-10), and increased lipid peroxidation and proinflammatory cytokines (IL-1β, IL-6, and TNF-α). Additionally, CP administration increased the level of acetylcholine esterase. Treatment with FRA significantly reversed these behavioral, and biochemical markers towards normal and mitigated CP-induced neurotoxic manifestation. PRACTICAL APPLICATIONS: Ferulic acid has a variety of pharmacological activities viz. anti-inflammatory, antioxidant, antimicrobial activity, anti-cancer, and anti-diabetic effects. The results of the present study showed that FRA mitigates the neurotoxicity (i.e., alteration of neurotransmitters, inflammation, and oxidative stress) induced by CP in mice. Treatment with FRA knowingly overturned the behavioral and biochemical markers in the direction of the moderated CP-influenced neurotoxic demonstration. Thus, FRA can be useful in the prevention of anticancer drugs induced neurotoxicity. Contrariwise, supplementary in-depth studies are obligatory to bring FRA from bench to bedside that it be used as an adjuvant among chemotherapeutically treated patients.

Interactions of Curcumin's Degradation Products with the Aβ42 Dimer: A Computational Study

Amyloid-β (Aβ) dimers are the smallest toxic species along the amyloid-aggregation pathway and among the most populated oligomeric accumulations present in the brain affected by Alzheimer's disease (AD). A proposed therapeutic strategy to avoid the aggregation of Aβ into higher-order structures is to develop molecules that inhibit the early stages of aggregation, i.e., dimerization. Under physiological conditions, the Aβ dimer is highly dynamic and does not attain a single well-defined structure but is rather characterized by an ensemble of conformations. In a recent study, a highly heterogeneous library of conformers of the Aβ dimer was generated by an efficient sampling method with constraints based on ion mobility mass spectrometry data. Here, we make use of the Aβ dimer library to study the interaction with two curcumin degradation products, ferulic aldehyde and vanillin, by molecular dynamics (MD) simulations. Ensemble docking and MD simulations are used to provide atomistic detail of the interactions between the curcumin degradation products and the Aβ dimer. The simulations show that the aromatic residues of Aβ, and in particular ¹⁹FF²⁰, interact with ferulic aldehyde and vanillin through π-π stacking. The binding of these small molecules induces significant changes on the ¹⁶KLVFF²⁰ region.

Recent Advances in the Neuroprotective Properties of Ferulic Acid in Alzheimer’s Disease: A Narrative Review

Alzheimer’s disease (AD) is a progressive degenerative disorder of the central nervous system, characterized by neuroinflammation, neurotransmitter deficits, and neurodegeneration, which finally leads to neuronal death. Emerging evidence highlighted that hyperglycemia and brain insulin resistance represent risk factors for AD development, thus suggesting the existence of an additional AD form, associated with glucose metabolism impairment, named type 3 diabetes. Owing to the limited pharmacological options, novel strategies, especially dietary approaches based on the consumption of polyphenols, have been addressed to prevent or, at least, slow down AD progression. Among polyphenols, ferulic acid is a hydroxycinnamic acid derivative, widely distributed in nature, especially in cereal bran and fruits, and known to be endowed with many bioactivities, especially antioxidant, anti-inflammatory and antidiabetic, thus suggesting it could be exploited as a possible novel neuroprotective strategy. Considering the importance of ferulic acid as a bioactive molecule and its widespread distribution in foods and medicinal plants, the aim of the present narrative review is to provide an overview on the existing preclinical and clinical evidence about the neuroprotective properties and mechanisms of action of ferulic acid, also focusing on its ability to modulate glucose homeostasis, in order to support a further therapeutic interest for AD and type 3 diabetes.

Isosteroidal alkaloids of Fritillaria taipaiensis and their implication to Alzheimer's disease: Isolation, structural elucidation and biological activity

Four undescribed and five known isosteroidal alkaloids were isolated from the bulbs of Fritillaria taipaiensis and their structures were elucidated on the basis of HR-ESI-MS, 1D and 2D NMR spectroscopic data analyses. The undescribed compounds were designated taipainines A-D. Of these, taipainine D presented a unique structure having the D/E trans (H-13α/H-17β) and E/F cis (β-axial lone pair of the N atom/H-22β) ring junctions. Possible biosynthetic pathway to taipainine D is proposed. Four compounds showed significant BChE inhibitory activities similar or better than the positive control galantamine. In addition, the preliminary structure-activity relationships (SARs) of these isosteroidal alkaloids were also investigated.

Medicine-food herb: Angelica sinensis, a potential therapeutic hope for Alzheimer's disease and related complications

Alzheimer's disease (AD) is a progressive neurodegenerative disease, which has brought a huge burden to the world. The current therapeutic approach of one-molecule-one-target strategy fails to address the issues of AD because of multiple pathological features of AD. Traditionally, the herb of Angelica sinensis (AS) comes from the root of an umbrella plant Angelica sinensis (Oliv.) Diels. As a typical medicine-food herb, studies have shown that AS can alleviate AD and AD-complications by multiple targets through the various foundations of pharmaceutical material and dietary supply basis. Therefore, this review summarizes the pharmacological effects of AS for the treatment of AD and AD-complications for the first time. AS contains many effective components, such as ligustilide, z-ligustilide, n-butylidenephthalide, α-pinene, p-cymene, myrcene, ferulic acid, vanillic acid and coniferyl ferulate. It is found that AS, AS-active compounds and AS-compound recipes mainly treat AD through neuroprotective, anti-inflammation, and anti-oxidant effects, improving mitochondrial dysfunction, anti-neuronal apoptosis, regulating autophagy, regulating intestinal flora and enhancing the central cholinergic system, which shows the multi-component and multi-target effect of AS. The role of dietary supplement components in AS for AD intervention is summarized, including vitamin B₁₂, folic acid, arginine, and oleic acid, which can improve the symptoms of AD. Besides, this review focuses on the safety and toxicity evaluation of AS, which provides a basis for its application. This review will provide further support for the research on AD and the application of medicine-food herb AS in a healthy lifestyle in the future.

Ferulic Acid as a Protective Antioxidant of Human Intestinal Epithelial Cells

The intestinal epithelial barrier is the primary and most significant defense barrier against ingested toxins and pathogenic bacteria. When the intestinal epithelium barrier is breached, inflammatory response is triggered. GWAS data showed that endoplasmic reticulum (ER) stress markers are elevated in Inflammatory Bowel Disease (IBD) patients, which suggests ER stress regulation might alleviate IBD symptoms. Ferulic acid (FA) is a polyphenol that is abundant in plants and has antioxidant and anti-inflammatory properties, although it is unclear whether FA has these effects on the intestine. Therefore, we investigated the effect of FA in vitro and in vivo. It was found that FA suppressed ER stress, nitric oxide (NO) generation, and inflammation in polarized Caco-2 and T84 cells, indicating that the ER stress pathway was implicated in its anti-inflammatory activities. The permeability of polarized Caco-2 cells in the presence and absence of proinflammatory cytokines were decreased by FA, and MUC2 mRNA was overexpressed in the intestines of mice fed a high-fat diet (HFD) supplemented with FA. These results suggest that FA has a protective effect on intestinal tight junctions. In addition, mouse intestine organoids proliferated significantly more in the presence of FA. Our findings shed light on the molecular mechanism responsible for the antioxidant effects of FA and its protective benefits on the health of the digestive system.

Dietary Intake of Polyphenols Enhances Executive/Attentional Functioning and Memory with an Improvement of the Milk Lipid Profile of Postpartum Women from Argentina

Puerperium may lead to memory and executive/attentional complaints that interfere with women’s daily life. This might be prevented by dietary compounds, such as neuroprotective polyphenols. Their bioactivity depends on their effects on lipid metabolism in different tissues, such as the brain, fat, and breast. Thus, a polyphenol-related cognitive improvement may be associated with changes of lipids in human milk, which are key for infant neurodevelopment. A cross-sectional study was conducted on 75 postpartum women from Córdoba (Argentina), involving several neuropsychological tests. Diet was registered to identify polyphenol intake and food pattern adherence, with sociodemographic and other psychological variables (insomnia, stress, subjective cognitive complaints) being also studied. Triacylglycerols, cholesterol, and their oxidative forms were analyzed as milk biomarkers. Multivariate statistical methods were applied. Results confirmed that women who consumed polyphenols presented better executive/attentional performance (i.e., higher correct responses, conceptual level responses, complete categories, verbal fluency; lower attentional interferences, and perseverative errors) and word retention with lower interference. Polyphenols were positively associated with milk lipids, which were higher in women with better cognition. Furthermore, they had lower oxidized triacylglycerols. In conclusion, polyphenolic intake during postpartum may improve executive/attentional functioning, memory, and milk lipid profile.

Mangifera indica ‘Namdokmai’ Prevents Neuronal Cells from Amyloid Peptide Toxicity and Inhibits BACE-1 Activities in a Drosophila Model of Alzheimer’s Amyloidosis

Alzheimer’s disease (AD) is a progressive neurological illness with few effective treatments. Thus, ameliorating the effects of AD using natural products has attracted global attention with promising efficacy and safety. In this study, ten tropical fruits including Ananas comosus ‘Phulae’, Ananas comosus ‘Pattavia’, Carica papaya ‘Khaekdum’, Carica papaya ‘Khaeknuan’, Durio zibethinus ‘Monthong’, Durio zibethinus ‘Chanee’, Psidium guajava ‘Kimju’, Psidium guajava ‘Keenok’, Mangifera indica ‘Kaew’ and Mangifera indica ‘Namdokmai’ were screened for their inhibitory activities against the key enzymes, cholinesterases and β-secretase (BACE-1), involved in AD pathogenesis. The top three fruit extracts with promising in vitro anti-AD activities were further investigated using rat pheochromocytoma PC-12 neuronal cell line and Drosophila AD model. Data showed that M. indica ‘Kaew’, M. indica ‘Namdokmai’ and P. guajava ‘Kimju’ reduced Aβ1–42-mediated neurotoxicity by promoting glutathione-dependent enzymes, while M. indica ‘Namdokmai’ limited Aβ1–42 peptide formation via BACE-1 inhibition and amended locomotory behavior of the Drosophila AD model. Results indicated the potential anti-AD properties of tropical fruits, particularly M. indica ‘Namdokmai’ in the prevention of Aβ1–42-mediated neurotoxicity and as a BACE-1 blocker.

Chemical Composition, Antioxidant and Anti-Enzymatic Activity of Golden Root (Rhodiola rosea L.) Commercial Samples

The aim of the study was to compare the chemical composition of the water and hydromethanolic extracts of R. rosea commercial samples in relation to their biological activity. For this purpose, the HPLC method was used for the determination of eleven phenolic compounds and AAS/AES was used for determination of five essential elements. Moreover, the contents of total phenolic, total flavonoid, total phenolic acids, and L(+)-ascorbic acid were determined. The antioxidant activity was assessed by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS radical scavenging activity, ferric-reducing/antioxidant power (FRAP), and cupric-reducing antioxidant capacity (CUPRAC) assays, while the inhibitory activity against AChE and BChE enzymes was determined using Ellman’s method. The results showed that the hydromethanolic extracts of R. rosea were richer in phenolic compounds and showed higher antioxidant and neurobiological activity than the water extracts. However, the water extracts gave higher contents of determined elements. Among the individual phenolic compounds gallic acid (2.33 mg/g DW) and sinapic acid (386.44 µg/g DW) had the highest concentrations in the hydromethanolic and water extracts, respectively. Moreover, the most extracts were observed to be more efficient on BChE. Moreover, the correlation analysis indicated a high positive relationship between chemical composition and biological activity in both extracts of R. rosea.

Natural products as novel scaffolds for the design of glycogen synthase kinase 3β inhibitors

INTRODUCTION

The different and relevant roles of GSK-3 are of critical importance since they deal with development, metabolic homeostasis, cell polarity and fate, neuronal growth and differentiation as well as modulation of apoptotic potential. Given their involvement with different diseases, many investigations have been undertaken with the aim of discovering new and promising inhibitors for this target. In this context, atural products represent an invaluable source of active molecules.

AREAS COVERED

In order to overcome issues such as poor pharmacokinetic properties or efficacy, frequently associated with natural compounds, different GSK-3β inhibitors belonging to alkaloid or flavonoid classes have been subjected to structural modifications in order to obtain more potent and safer compounds. Herein, the authors report the results obtained from studies where natural compounds have been used as hits with the aim of providing new kinase inhibitors endowed with a better inhibitory profile.

EXPERT OPINION

Structurally modification of natural scaffolds is a proven approach taking advantage of their pharmacological characteristics. Indeed, whatever the strategy adopted is and, despite the limitations associated with the structural complexity of natural products, the authors recommend the use of natural scaffolds as a promising strategy for the discovery of novel and potent GSK-3β inhibitors.

Medicine-Food Herbs against Alzheimer’s Disease: A Review of Their Traditional Functional Features, Substance Basis, Clinical Practices and Mechanisms of Action

Alzheimer’s disease (AD) is a progressive, neurodegenerative disorder that currently has reached epidemic proportions among elderly populations around the world. In China, available traditional Chinese medicines (TCMs) that organically combine functional foods with medicinal values are named “Medicine Food Homology (MFH)”. In this review, we focused on MFH varieties for their traditional functional features, substance bases, clinical uses, and mechanisms of action (MOAs) for AD prevention and treatment. We consider the antiAD active constituents from MFH species, their effects on in vitro/in vivo AD models, and their drug targets and signal pathways by summing up the literature via a systematic electronic search (SciFinder, PubMed, and Web of Science). In this paper, several MFH plant sources are discussed in detail from in vitro/in vivo models and methods, to MOAs. We found that most of the MFH varieties exert neuroprotective effects and ameliorate cognitive impairments by inhibiting neuropathological signs (Aβ-induced toxicity, amyloid precursor protein, and phosphorylated Tau immunoreactivity), including anti-inflammation, antioxidative stress, antiautophagy, and antiapoptosis, etc. Indeed, some MFH substances and their related phytochemicals have a broad spectrum of activities, so they are superior to simple single-target drugs in treating chronic diseases. This review can provide significant guidance for people’s healthy lifestyles and drug development for AD prevention and treatment.

The Use of Bioactive Compounds in Hyperglycemia- and Amyloid Fibrils-Induced Toxicity in Type 2 Diabetes and Alzheimer’s Disease

It has become increasingly apparent that defective insulin signaling may increase the risk for developing Alzheimer’s disease (AD), influence neurodegeneration through promotion of amyloid formation or by increasing inflammatory responses to intraneuronal β-amyloid. Recent work has demonstrated that hyperglycemia is linked to cognitive decline, with elevated levels of glucose causing oxidative stress in vulnerable tissues such as the brain. The ability of β-amyloid peptide to form β-sheet-rich aggregates and induce apoptosis has made amyloid fibrils a leading target for the development of novel pharmacotherapies used in managing and treatment of neuropathological conditions such as AD-related cognitive decline. Additionally, deposits of β-sheets folded amylin, a glucose homeostasis regulator, are also present in diabetic patients. Thus, therapeutic compounds capable of reducing intracellular protein aggregation in models of neurodegenerative disorders may prove useful in ameliorating type 2 diabetes mellitus symptoms. Furthermore, both diabetes and neurodegenerative conditions, such as AD, are characterized by chronic inflammatory responses accompanied by the presence of dysregulated inflammatory biomarkers. This review presents current evidence describing the role of various small bioactive molecules known to ameliorate amyloidosis and subsequent effects in prevention and development of diabetes and AD. It also highlights the potential efficacy of peptide–drug conjugates capable of targeting intracellular targets.

Natural Products as Sources of Multitarget Compounds: Advances in the Development of Ferulic Acid as Multitarget Therapeutic

Nature has provided therapeutic substances for millennia, with many valuable medications derived from plant sources. Multitarget drugs become essential in the management of various disorders including hepatic disorders, neurological disorders, diabetes, and carcinomas. Ferulic acid is a significant potential therapeutic agent, which is easily available at low cost, possesses a low toxicity profile, and has minimum side effects. Ferulic acid exhibits various therapeutic actions by modulation of various signal transduction pathways such as Nrf2, p38, and mTOR. The actions exhibited by ferulic acid include anti-apoptosis, antioxidant, anti-inflammatory, antidiabetic, anticarcinogenic, hepatoprotection, cardioprotection, activation of transcriptional factors, expression of genes, regulation of enzyme activity, and neuroprotection, which further help in treating various pathophysiological conditions such as cancer, skin diseases, brain disorders, diabetes, Parkinson's disease, Alzheimer's disease, hypoxia, hepatic disorders, H1N1 flu, and viral infections. The current review focuses on the significance of natural products as sources of multitarget compounds and a primary focus has been made on ferulic acid and its mechanism, role, and protective action in various ailments.

Nanotechnology-Based Drug Delivery Strategies to Repair the Mitochondrial Function in Neuroinflammatory and Neurodegenerative Diseases

Mitochondria are vital organelles in eukaryotic cells that control diverse physiological processes related to energy production, calcium homeostasis, the generation of reactive oxygen species, and cell death. Several studies have demonstrated that structural and functional mitochondrial disturbances are involved in the development of different neuroinflammatory (NI) and neurodegenerative (ND) diseases (NI&NDDs) such as multiple sclerosis, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Remarkably, counteracting mitochondrial impairment by genetic or pharmacologic treatment ameliorates neurodegeneration and clinical disability in animal models of these diseases. Therefore, the development of nanosystems enabling the sustained and selective delivery of mitochondria-targeted drugs is a novel and effective strategy to tackle NI&NDDs. In this review, we outline the impact of mitochondrial dysfunction associated with unbalanced mitochondrial dynamics, altered mitophagy, oxidative stress, energy deficit, and proteinopathies in NI&NDDs. In addition, we review different strategies for selective mitochondria-specific ligand targeting and discuss novel nanomaterials, nanozymes, and drug-loaded nanosystems developed to repair mitochondrial function and their therapeutic benefits protecting against oxidative stress, restoring cell energy production, preventing cell death, inhibiting protein aggregates, and improving motor and cognitive disability in cellular and animal models of different NI&NDDs.

An overview of recent analysis and detection of acetylcholine

Acetylcholine (ACh), the major neurotransmitter secreted by cholinergic neurons, is widely found in the peripheral and central nervous systems, and its main function is to complete the transmission of neural signals. When cholinergic neurons are impaired, the synthesis and decomposition of ACh are abnormal and the neural signalling transition is blocked. To some extent, the concentration changes of ACh reflects the occurrence and development of many kinds of nervous system diseases, such as Alzheimer's disease, Parkinson's disease, Myasthenia gravis and so on. Thus, researches of the physiological and pathological roles and the tracking of the concentration changes of ACh in vivo are significant to the prevention and treatment of these diseases. In the paper, the pathophysiological functions and the comprehensive research progress on detection methods of ACh are summarized. Specifically, the latest research and related applications of the optical and electrochemical biosensors are described, and the future development directions and challenges are prospected, which provides a reference for the detection and applications of ACh.

Hybrid Quinoline-Thiosemicarbazone Therapeutics as a New Treatment Opportunity for Alzheimer's Disease‒Synthesis, In Vitro Cholinesterase Inhibitory Potential and Computational Modeling Analysis

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. The limited pharmacological approaches based on cholinesterase inhibitors only provide symptomatic relief to AD patients. Moreover, the adverse side effects such as nausea, vomiting, loss of appetite, muscle cramps, and headaches associated with these drugs and numerous clinical trial failures present substantial limitations on the use of medications and call for a detailed insight of disease heterogeneity and development of preventive and multifactorial therapeutic strategies on urgent basis. In this context, we herein report a series of quinoline-thiosemicarbazone hybrid therapeutics as selective and potent inhibitors of cholinesterases. A facile multistep synthetic approach was utilized to generate target structures bearing multiple sites for chemical modifications and establishing drug-receptor interactions. The structures of all the synthesized compounds were fully established using readily available spectroscopic techniques (FTIR, ¹H- and ¹³C-NMR). In vitro inhibitory results revealed compound 5b as a promising and lead inhibitor with an IC₅₀ value of 0.12 ± 0.02 μM, a 5-fold higher potency than standard drug (galantamine; IC₅₀ = 0.62 ± 0.01 μM). The synergistic effect of electron-rich (methoxy) group and ethylmorpholine moiety in quinoline-thiosemicarbazone conjugates contributes significantly in improving the inhibition level. Molecular docking analysis revealed various vital interactions of potent compounds with amino acid residues and reinforced the in vitro results. Kinetics experiments revealed the competitive mode of inhibition while ADME properties favored the translation of identified inhibitors into safe and promising drug candidates for pre-clinical testing. Collectively, inhibitory activity data and results from key physicochemical properties merit further research to ensure the design and development of safe and high-quality drug candidates for Alzheimer’s disease.

Multifunctional Small Molecules as Potential Anti-Alzheimer's Disease Agents

Alzheimer's disease (AD) is a severe multifactorial neurodegenerative disorder characterized by a progressive loss of neurons in the brain. Despite research efforts, the pathogenesis and mechanism of AD progression are not yet completely understood. There are only a few symptomatic drugs approved for the treatment of AD. The multifactorial character of AD suggests that it is important to develop molecules able to target the numerous pathological mechanisms associated with the disease. Thus, in the context of the worldwide recognized interest of multifunctional ligand therapy, we report herein the synthesis, characterization, physicochemical and biological evaluation of a set of five (1a-e) new ferulic acid-based hybrid compounds, namely feroyl-benzyloxyamidic derivatives enclosing different substituent groups, as potential anti-Alzheimer's disease agents. These hybrids can keep both the radical scavenging activity and metal chelation capacity of the naturally occurring ferulic acid scaffold, presenting also good/mild capacity for inhibition of self-Aβ aggregation and fairly good inhibition of Cu-induced Aβ aggregation. The predicted pharmacokinetic properties point towards good absorption, comparable to known oral drugs.

Further SAR studies on natural template based neuroprotective molecules for the treatment of Alzheimer's disease

In our earlier paper, we described ferulic acid (FA) template based novel series of multifunctional cholinesterase (ChE) inhibitors for the management of AD. This report has further extended the structure-activity relationship (SAR) studies of this series of molecules in a calibrated manner to improve upon the ChEs inhibition and antioxidant property to identify the novel potent multifunctional molecules. To investigate the effect of replacement of phenylpiperazine ring with benzylpiperazine, increase in the linker length between FA and substituted phenyl ring, and replacement of indole moiety with tryptamine on this molecular template, three series of novel molecules were developed. All synthesized compounds were tested for their acetyl and butyryl cholinestrases (AChE and BChE) inhibitory properties. Enzyme inhibition and PAS binding studies identified compound 13b as a lead molecule with potent inhibitor property towards AChE/BChE (AChE IC₅₀ = 0.96 ± 0.14 µM, BChE IC₅₀ = 1.23 ± 0.23 µM) compared to earlier identified lead molecule EJMC-G (AChE IC₅₀ = 5.74 ± 0.13 μM, BChE IC₅₀ = 14.05 ± 0.10 μM, respectively). Molecular docking and dynamics studies revealed that 13b fits well into the active sites of AChE and BChE, forming stable and strong interactions with key residues Trp86, Ser125, Glu202, Trp 286, Phe295, Tyr 337 in AChE, and with Trp 82, Gly115, Tyr128, and Ser287 in BChE. The compound, 13b was found to be three times more potent antioxidant in a DPPH assay (IC₅₀ = 20.25 ± 0.26 µM) over the earlier identified EJMC-B (IC₅₀ = 61.98 ± 0.30 µM) and it also was able to chelate iron. Co-treatment of 13b with H₂O₂, significantly attenuated and reversed H₂O₂-induced toxicity in the SH-SY5Y cells. The parallel artificial membrane permeability assay-blood brain barrier (PAMPA-BBB) revealed that 13b could cross BBB efficiently. Finally, the in-vivo efficacy of 13b at dose of 10 mg/kg in scopolamine AD model has been demonstrated. The present study strongly suggests that the naturally inspired multifunctional molecule 13b may behave as a potential novel therapeutic agent for AD management.

Simultaneous Determination of Seven Bioactive Constituents from Salvia miltiorrhiza in Rat Plasma by HPLC-MS/MS: Application to a Comparative Pharmacokinetic Study

The roots of Salvia miltiorrhiza (Danshen) is a precious herbal medicine used to treat cardiovascular diseases. This study establishes a high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method to quantify seven bioactive constituents from Danshen in rat plasma simultaneously. Chromatographic separation is performed on an Agilent Eclipse Plus C18 column (150 mm × 2.1 mm, 5 μm), utilizing a gradient of acetonitrile and 0.2% formic acid aqueous solution as the mobile phase, at a flow rate of 0.6 mL/min. We conduct a tandem mass spectrometric detection with electrospray ionization (ESI) interface via multiple reaction monitoring (MRM) in both positive and negative ionization mode. Our results show that a linear relationship is established for each analyte of interest over the concentration range of 0.5–300 ng/mL with r ≥ 0.9976. The validated method is successfully used to compare the pharmacokinetic properties of crude and wine-processed Danshen extract orally administered to rats. Cmax of tanshinone IIA, Cmax, and AUC0-t of dihydrotanshinone I decrease significantly (p < 0.05) in the wine-processed group. No significant changes for other compounds are observed. These results might provide meaningful information for the further application of wine-processed Danshen and understanding of wine-processing mechanisms.

Dietary Phenolic Acids and Their Major Food Sources Are Associated with Cognitive Status in Older Italian Adults

BACKGROUND

Life expectancy is increasing along with the rising prevalence of cognitive disorders. Among the factors that may contribute to their prevalence, modifiable risk factors such as diet may be of primary importance. Unarguably, plant-based diets rich in bioactive compounds, such as polyphenols, showed their potential in decreasing risk of neurodegenerative disorders. Therefore, the aim of the present study is to investigate whether exposure to components of plant-based diets, namely phenolic acids, may affect cognitive status in older Italian adults.

METHODS

The demographic, lifestyle and dietary habits of a sample of individuals living in southern Italy were analyzed. Dietary intake was assessed through food frequency questionnaires (FFQs). Data on the phenolic acids content in foods were estimated using the Phenol-Explorer database. Cognitive status was evaluated using The Short Portable Mental Status Questionnaire. Multivariate logistic regression analyses were used to assess the associations.

RESULTS

The mean intake of phenolic acids was 346.6 mg/d. After adjustment for potential confounding factors, individuals in the highest quartile of total phenolic acid intake were less likely to have impaired cognitive status (OR = 0.36 (95% CI: 0.14, 0.92)); similarly, the analysis for subclasses of phenolic acids showed the beneficial effect toward cognitive status of greater intake of hydroxycinnamic acids (OR = 0.35 (95% CI: 0.13, 0.91)). Among individual compounds, only higher intake of caffeic acid was inversely associated with impaired cognitive status (OR = 0.32 (95% CI: 0.11, 0.93)); notably, the association with ferulic acid intake was significant only when adjusting for background characteristics, and not for adherence to the Mediterranean diet.

CONCLUSIONS

This study revealed that greater intakes of dietary phenolic acids were significantly inversely associated with impaired cognition, emphasizing the possible role of phenolic acids in the prevention of cognitive disorders.