Phytochemical investigation and biological activity of Doronicum pardalianches L. roots against Alzheimer's disease.

The methanol extract of Doronicum pardalianches L. was fractionated using n-hexane, chloroform, and ethyl acetate to evaluate their cholinesterase (ChE) inhibitory activity via modified Ellman's method. It was perceived that only the ethyl acetate fraction was active toward acetylcholinesterase (AChE) with IC50 value of 172.21 µg/mL. Also, all fractions showed no butyrylcholinesterase (BChE) inhibitory activity. The ethyl acetate fraction was also investigated for its neuroprotectivity and metal chelating ability (Zn2+, Fe2+, and Cu2+) which demonstrated desired activity. Phytochemical analysis of the ethyl acetate fraction led to isolation and identification of formononetin 7-O-ß-D-glucopyranoside which has not been previously reported for this plant.

Phytochemical analysis and anticholinesterase activity of aril of Myristica fragrans Houtt.

In this study, the ethyl acetate fraction of Myristica fragrans Houtt. was investigated for its in vitro anticholinesterase activity as well as neuroprotectivity against H2O2-induced cell death in PC12 neuronal cells and the ability to chelate bio-metals (Zn2+, Fe2+, and Cu2+). The fraction was inactive toward acetylcholinesterase (AChE); however, it inhibited the butyrylcholinesterase (BChE) with IC50 value of 68.16 µg/mL, compared with donepezil as the reference drug (IC50 = 1.97 µg/mL) via Ellman's method. It also showed good percentage of neuroprotection (86.28% at 100 µg/mL) against H2O2-induced neurotoxicity and moderate metal chelating ability toward Zn2+, Fe2+, and Cu2+. The phytochemical study led to isolation and identification of malabaricone A (1), malabaricone C (2), 4-(4-(3,4-dimethoxyphenyl)-2,3-dimethylbutyl)benzene-1,2-diol (3), nectandrin B (4), macelignan (5), and 4-(4-(benzo[d][1,3]dioxol-5-yl)-1-methoxy-2,3-dimethylbutyl)-2-methoxyphenol (6) which were assayed for their cholinesterase (ChE) inhibitory activity. Compounds 1 and 3 were not previously reported for M. fragrans. Among isolated compounds, compound 2 showed the best activity toward both AChE and BChE with IC50 values of 25.02 and 22.36 µM, respectively, compared with donepezil (0.07 and 4.73 µM, respectively).

Cinnamomum verum J. Presl. Bark essential oil: in vitro investigation of anti-cholinesterase, anti-BACE1, and neuroprotective activity.

BACKGROUND: Cinnamomum verum J. Presl. (Lauraceae), Myrtus communis L. (Myrtaceae), Ruta graveolens L. (Rutaaceae), Anethum graveolens L. (Apiaceae), Myristica fragrans Houtt. (Myristicaceae), and Crocus sativus L. (Iridaceae) have been recommended for improvement of memory via inhalation, in Iranian Traditional Medicine (ITM). In this respect, the essential oils (EOs) from those plants were obtained and evaluated for cholinesterase (ChE) inhibitory activity as ChE inhibitors are the available drugs in the treatment of Alzheimer's disease (AD). METHODS: EOs obtained from the plants under investigation, were evaluated for their potential to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in vitro based on the modified Ellman's method. The most potent EO was candidate for the investigation of its beta-secretase 1 (BACE1) inhibitory activity and neuroprotectivity. RESULTS: Among all EOs, C. verum demonstrated the most potent activity toward AChE and BChE with IC50 values of 453.7 and 184.7 µg/mL, respectively. It also showed 62.64% and 41.79% inhibition against BACE1 at the concentration of 500 and 100 mg/mL, respectively. However, it depicted no neuroprotective potential against ß-amyloid (Aß)-induced neurotoxicity in PC12 cells. Also, identification of chemical composition of C. verum EO was achieved via gas chromatography-mass spectrometry (GC-MS) analysis and the major constituent; (E)-cinnamaldehyde, was detected as 68.23%. CONCLUSION: Potent BChE inhibitory activity of C. verum EO can be considered in the development of cinnamon based dietary supplements for the management of patients with advanced AD.

Phytochemical investigation and anticholinesterase activity of ethyl acetate fraction of Myristica fragrans Houtt. seeds.

In this work, n-hexane, chloroform, and ethyl acetate fractions of the methanol extract of Myristica fragrans Houtt. seeds were evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) via Ellman's method. It was found that all fractions depicted no anti-AChE activity, however, they were active toward BChE with IC50 values of 361.8, 215.0, and 145.8 µg/mL, respectively comparing with donepezil as the reference drug (IC50 = 1.97 µg/mL). The ethyl acetate fraction which also showed high neuroprotectivity and metal chelating ability was selected for the phytochemical analysis. Our results confirmed the presence of trimyristin and 5,7-diacetyl chrysin (reported for the first time in M. fragrans) in the corresponding fraction.

Azobioisosteres of Curcumin with Pronounced Activity against Amyloid Aggregation, Intracellular Oxidative Stress, and Neuroinflammation.

Many (poly-)phenolic natural products, for example, curcumin and taxifolin, have been studied for their activity against specific hallmarks of neurodegeneration, such as amyloid-ß 42 (Aß42) aggregation and neuroinflammation. Due to their drawbacks, arising from poor pharmacokinetics, rapid metabolism, and even instability in aqueous medium, the biological activity of azobenzene compounds carrying a pharmacophoric catechol group, which have been designed as bioisoteres of curcumin has been examined. Molecular simulations reveal the ability of these compounds to form a hydrophobic cluster with Aß42, which adopts different folds, affecting the propensity to populate fibril-like conformations. Furthermore, the curcumin bioisosteres exceeded the parent compound in activity against Aß42 aggregation inhibition, glutamate-induced intracellular oxidative stress in HT22 cells, and neuroinflammation in microglial BV-2 cells. The most active compound prevented apoptosis of HT22 cells at a concentration of 2.5 µm (83 % cell survival), whereas curcumin only showed very low protection at 10 µm (21 % cell survival).

Design and synthesis of multi-target directed 1,2,3-triazole-dimethylaminoacryloyl-chromenone derivatives with potential use in Alzheimer's disease.

To discover multifunctional agents for the treatment of Alzheimer's disease (AD), a new series of 1,2,3-triazole-chromenone derivatives were designed and synthesized based on the multi target-directed ligands approach. The in vitro biological activities included acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition as well as anti-Aß aggregation, neuroprotective effects, and metal-chelating properties. The results indicated a highly selective BuChE inhibitory activity with an IC50 value of 21.71 µM for compound 10h as the most potent compound. Besides, compound 10h could inhibit self-induced Aß1-42 aggregation and AChE-induced Aß aggregation with 32.6% and 29.4% inhibition values, respectively. The Lineweaver-Burk plot and molecular modeling study showed that compound 10h targeted both the catalytic active site (CAS) and peripheral anionic site (PAS) of BuChE. It should be noted that compound 10h was able to chelate biometals. Thus, the designed scaffold could be considered as multifunctional agents in AD drug discovery developments.

Design and Synthesis of Novel Arylisoxazole-Chromenone Carboxamides: Investigation of Biological Activities Associated with Alzheimer's Disease.

A novel series of hybrid arylisoxazole-chromenone carboxamides were designed, synthesized, and evaluated for their cholinesterase (ChE) inhibitory activity based on the modified Ellman's method. Among synthesized compounds, 5-(3-nitrophenyl)-N-{4-[(2-oxo-2H-1-benzopyran-7-yl)oxy]phenyl}-1,2-oxazole-3-carboxamide depicted the most acetylcholinesterase (AChE) inhibitory activity (IC50 =1.23 µm) and 5-(3-chlorophenyl)-N-{4-[(2-oxo-2H-1-benzopyran-7-yl)oxy]phenyl}-1,2-oxazole-3-carboxamide was found to be the most potent butyrylcholinesterase (BChE) inhibitor (IC50 =9.71 µm). 5-(3-Nitrophenyl)-N-{4-[(2-oxo-2H-1-benzopyran-7-yl)oxy]phenyl}-1,2-oxazole-3-carboxamide was further investigated for its BACE1 inhibitory activity as well as neuroprotectivity and metal chelating ability as important factors involved in onset and progress of Alzheimer's disease. It could inhibit BACE1 by 48.46 % at 50 µm. It also showed 6.4 % protection at 25 µm and satisfactory chelating ability toward Zn2+ , Fe2+ , and Cu2+ ions. Docking studies of 5-(3-nitrophenyl)-N-{4-[(2-oxo-2H-1-benzopyran-7-yl)oxy]phenyl}-1,2-oxazole-3-carboxamide and 5-(3-chlorophenyl)-N-{4-[(2-oxo-2H-1-benzopyran-7-yl)oxy]phenyl}-1,2-oxazole-3-carboxamide confirmed desired interactions with those amino acid residues of the AChE and BChE, respectively.

Anti-cholinesterase and Neuroprotective Activities of Sweet and Bitter Apricot Kernels (Prunus armeniaca L.).

Apricot (Prunus armeniaca L.) is a fruit cultivated in various parts of the world. Both sweet and bitter kernels of apricot have been used for the treatment of different diseases such as loss of memory in Iranian traditional medicine (ITM). In the present study, the inhibitory activity of sweet and bitter extracts of apricot kernels towards cholinesterase (ChE) enzymes, both acetyl and butyrylcholinesterase was examined through Ellman's method. In addition, neuroprotectivity of aqueous extracts and amygdalin were investigated against H2O2-induced cell death in PC12 neurons. Among them, the best acetylcholinesterase (AChE) inhibitory activity (IC50 = 134.93 ± 2.88 µg/mL) and neuroprotectivity (P-value < 0.0001) were obtained by the aqueous extract of bitter type. It was found that all extracts showed no butyrylcholinesterase (BChE) inhibitory activity.

Investigation of polysaccharide extracts from Iranian and French strains of Agaricus subrufescens against enzymes involved in Alzheimer's disease / Investigación de extractos de polisacáridos de cepas iraníes y francesas de Agaricus subrufescens contra enzimas relevantes para la enfermedad de Alzheimer

In this work, the inhibitory activity of a wide range of polysaccharide extracts from two Iranian and French strains of Agaricus subrufescens were evaluated toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Among them, two extracts S9 and S'7 obtained from Iranian and French strains under different extraction conditions showed selective AChE inhibitory activity with IC50 values of 154.63 and 145.43 µg/mL, respectively. It should be noted that all extracts from both strains demonstrated no BChE inhibitory activity. S9 and S'7 were also tested for their effect on amyloid beta (Aß) aggregation, antioxidant activity, and neuroprotectivity. Their activity against Aß aggregation was comparable to that of donepezil as the reference drug but they induced moderate antioxidant activity by DPPH radical scavenging activity and negligible neuroprotectivity against Aß-induced damage.

En este trabajo, se evaluó la actividad inhibitoria de acetilcolinesterasa (AChE) y butirilcolinesterasa (BChE) para varios extractos de polisacáridos de dos cepas iraníes y francesas de Agaricus subrufescens. Los extractos más potentes mostraron valores de IC50 de 154,63 y 145 µg/ml para las cepas iraní (S9) y francesa (S'7), respectivamente, las cuales se obtuvieron de diferentes condiciones de extracción; sin embargo, todos los extractos no mostraron actividad inhibitoria de BChE. Además, S9 y S'7 se probaron para determinar su efecto sobre la agregación de beta-amiloide (Aß), así como su actividad antioxidante y neuroprotectora. Su actividad inhibitoria de la agregación de Aß fue comparable con donepezil, fármaco de referencia, pero indujeron una actividad antioxidante moderada, medida mediante la captación de radicales DPPH, y una neuroprotectora insignificante contra el daño inducido por Aß.

Novel N-benzylpyridinium moiety linked to arylisoxazole derivatives as selective butyrylcholinesterase inhibitors: Synthesis, biological evaluation, and docking study.

A novel series of N-benzylpyridinium moiety linked to arylisoxazole ring were designed, synthesized, and evaluated for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Synthesized compounds were classified into two series of 5a-i and 5j-q considering the position of positively charged nitrogen of pyridinium moiety (3- or 4- position, respectively) connected to isoxazole carboxamide group. Among the synthesized compounds, compound 5n from the second series of compounds possessing 2,4-dichloroaryl group connected to isoxazole ring was found to be the most potent AChE inhibitor (IC50 = 5.96 µM) and compound 5j also from the same series of compounds containing phenyl group connected to isoxazole ring demonstrated the most promising inhibitory activity against BChE (IC50 = 0.32 µM). Also, kinetic study demonstrated competitive inhibition mode for both AChE and BChE inhibitory activity. Docking study was also performed for those compounds and desired interactions with those active site amino acid residues were confirmed through hydrogen bonding as well as π-π and π-anion interactions. In addition, the most potent compounds were tested against BACE1 and their neuroprotectivity on Aß-treated neurotoxicity in PC12 cells which depicted negligible activity. It should be noted that most of the synthesized compounds from both categories 5a-i and 5j-q showed a significant selectivity toward BChE. However, series 5j-q were more active toward AChE than series 5a-i.

Design, synthesis and anti-Alzheimer's activity of novel 1,2,3-triazole-chromenone carboxamide derivatives.

Alzheimer's disease (AD) is a well-known neurodegenerative disorder affecting millions of old people worldwide and the corresponding epidemiological data highlights the significance of the disease. As AD is a multifactorial illness, various single-target directed drugs that have reached clinical trials have failed. Therefore, various factors associated with outset of AD have been considered in targeted drug discovery and development. In this work, a wide range of 1,2,3-triazole-chromenone carboxamides were designed, synthesized, and evaluated for their cholinesterase inhibitory activity. Among them, N-(1-benzylpiperidin-4-yl)-7-((1-(3,4-dimethylbenzyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-oxo-2H-chromene-3-carboxamide (11b) showed the best acetylcholinesterase inhibitory activity (IC50 = 1.80 µM), however, it was inactive toward butyrylcholinesterase. It should be noted that compound 11b was evaluated for its BACE1 inhibitory activity and calculated IC50 = 21.13 µM confirmed desired inhibitory activity. Also, this compound revealed satisfactory neuroprotective effect against H2O2-induced cell death in PC12 neurons at 50 µM as well as metal chelating ability toward Fe2+, Cu2+, and Zn2+ ions.

Zinc oxide nanoparticles (ZnO NP) mediated regulation of bacosides biosynthesis and transcriptional correlation of HMG-CoA reductase gene in suspension culture of Bacopa monnieri.

Bacopa monnieri (L.) Wettst. is a well documented nootropic plant, extensive known for alleviating symptoms of neurological disorder, along with other symptomatic relief. This property is attributed to the active phytocompounds, saponins (bacoside A) present in the plant. However, lack of stringent validation guidelines in most of the countries bring to the market, formulations differing in phytocompounds yield, thereby suggesting possible variation in therapeutic efficacy. The in-vitro suspension cultures of the Bacopa monnieri, provide an ease of scale-up, but regulating saponin yield is a stringent task. The aim of the study is to explore the effects of different concentrations (0, 0.25, 0.50, 0.75 and 1.0 ppm) of zinc oxide nanoparticles (ZnO NP) (24 nm in size), in regulating growth rate, bacoside yield and transcriptional profile of HMG CoA reductasegene in the suspension cells of Bacopa monnieri. Results showed a linear correlation between Bacoside A yield and ZnO NP concentrations with around 2 fold increase in total bacoside A concentration at 1 ppm. Also, ZnO NP supplemented suspension cells showed variation in the specific growth rate. Neuroprotective properties, analyzed using methanolic extracts of suspension cells again obtrude the extract of ZnO NP supplemented (0.75 ppm and 1 ppm) culture for better response in alleviating oxidative stress mediated damage to neuronal cells. ZnO NP supplemented system showed lower expression of HMG CoA reductasegene (the rate limiting step in bacoside A biosynthesis) but higher concentration of bacoside A, suggesting possible role of ZnO NP in isoprenoid pathway than MVA pathways.

Efficient Discovery of Quality Control Markers for Gastrodia elata Tuber by Fingerprint-Efficacy Relationship Modelling.

INTRODUCTION: Gastrodia elata tuber (GET) has been widely used in China as a famous herbal medicine. However, the quality control markers (QCMs) for GET still need further investigation. OBJECTIVE: To develop a rational strategy based on fingerprint-efficacy relationship modelling to discover the efficacy-related QCMs, using GET as a case study. METHODOLOGY: The high-performance liquid chromatography (HPLC) fingerprints of 13 batches of GET extracts were established and 10 common peaks were structurally characterised by HPLC coupled with quadrupole time-of-flight mass spectrometry (QTOF-MS). The neuroprotective effects of GET samples were evaluated using the in vitro model of ß-amyloid peptide (Aß25-35 )-induced PC12 cell death. The fingerprint-efficacy relationship of chemical fingerprints and neuroprotective effects was linked by orthogonal projection to latent structure-discriminant analysis (OPLS-DA) model. RESULTS: The chemical combination of 5-hydroxymethyl-2-furaldehyde (5-HMF), parishin B (PB) and parishin C (PC) was discovered and confirmed as QCMs of GET by the OPLS-DA method. The selected QCMs allowed to evaluate the relative quality of GET samples. CONCLUSION: This study has demonstrated that the rational strategy based on fingerprint-efficacy relationship modelling might be generally applicable for the quality control of herbal medicines. Copyright © 2017 John Wiley & Sons, Ltd.

Design, synthesis and biological evaluation of pyridazino[3,4,5-de]quinazolin-3(2H)-one as a new class of PARP-1 inhibitors.

A series of pyridazino[3,4,5-de]quinazolin-3(2H)-one derivatives were designed and synthesized as PARP-1 inhibitors. Most of the synthesized compounds showed good inhibitory activities of PARP-1 and four of them achieved at the IC50 values ranging from 0.0914 µM to 0.244 µM. Two compounds, 1a and 1b, were further tested for their neuroprotective effect in the PC12 cell model injured by H2O2 and both of them exhibited excellent activities.