Butyrylcholinesterase Inhibitory Activity Research Articles

Neuroprotective, neurite enhancing, and cholinesterase inhibitory effects of Lamiaceae family essential oils in Alzheimer’s disease model

IntroductionThe present study investigates the cholinesterase inhibitory and neuritogenic activities of selected essential oils from the Lamiaceae family, as well as their neuroprotective and antioxidant potential against scopolamine-induced cytotoxicity in SH-SY5Y cells. MethodsThe anticholinesterase activity was analysed using a modified Ellman’s assay. The neuroprotective potential was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Intracellular reactive oxygen species (ROS) levels were quantified using 2',7’- dichlorofluorescin diacetate assay. A neurite outgrowth assay was employed to evaluate the neuritogenic activity. ResultsOregano leaf (terpineol-type), peppermint leaf, rosemary, and sage essential oils have antibutyrylcholinesterase activity, while oregano leaf (phenol-type) essential oil has both acetylcholinesterase and butyrylcholinesterase inhibitory activities. Pretreatment with lavender flower essential oil (30 µg/mL), linalool, and linalyl acetate for 24 hours protects against scopolamine-induced toxicity. Linalool also displayed a significant decrease in intracellular ROS. The oregano leaf (terpineol-type), peppermint, rosemary, and sage essential oils at 100 µg/mL exhibited neuritogenic activity, with the highest activity being observed with oregano leaf (terpineol-type) essential oil. Discussion/ConclusionsEssential oils from plants of Lamiaceae family displayed anticholinesterase, neuroprotective, antioxidant, and neuritogenic activities. These properties demonstrate their potential as complementary treatments to prevent and/or delay dementia-related diseases such as Alzheimer’s disease.

Dictamnine derivatives as a novel family of dual inhibitors for cholinesterase and β-amyloid aggregation

A novel series of dictamnine derivatives were synthesized and evaluated as dual inhibitors for cholinesterase and β-amyloid aggregation. These molecules exhibited potent acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities at the micromolar to sub-micromolar levels. Compound 7k exhibited the strongest inhibitory activity for both AChE and BChE, with IC50 values of 0.40 μM and 0.63 μM, respectively, improving results from its precursor dictamnine and the commercial inhibitor galanthamine. Kinetic analyses and molecular modeling results indicated a mixed-type inhibition of AChE by compound 7k. In addition, some of the derivatives revealed potent inhibitory activity of AChE induced β-amyloid (Aβ) aggregation. Moreover, 7k did not show toxicity against SH-SY5Y and HL-7702 cells at the tested concentration. Therefore, these dictamnine derivatives, and especially 7k, are suitable candidates for the treatment of Alzheimer's disease and should be further studied.

Constituents and Selective BuChE Inhibitory Activity of the Essential Oil from Hypericum aciculare Kunth.

A potential source of new inhibitors of cholinesterase enzymes are certain compounds of natural plant origin; therefore, in the study described herein we have determined the chemical composition and the acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities of the essential oil (EO) steam distilled from aerial parts of Hypericum aciculare, which was collected in southern Ecuador. The oil qualitative and quantitative composition was determined by GC-FID and GC-MS using a non-polar and a polar chromatographic column. A total of fifty-three constituents were identified, that accounted for about 98% of the EO content. The hydrocarbon n-nonane (16.4-28.7%) and the aldehyde n-decanal (20.7-23.1%) were the predominant oil constituents. In addition, the EO showed significant inhibition of BuChE (IC50 = 28.3 ± 2.7 μg/mL) and moderate activity towards AChE (IC50 = 82.1 ± 12.1 µg/mL). Thus, the EO from H. aciculare aerial parts is an interesting candidate to investigate the mechanism of selective ChE inhibition by the two ChE enzymes with the aim to discover potential targets to control the progression of the Alzheimer's disease (AD).

1,2,3-Triazolo[4,5-b]aminoquinolines: Design, synthesis, structure, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, and molecular docking of novel modified tacrines

An efficient [4 + 2] cyclization protocol to synthesize a series of twelve examples of 1,2,3-triazolo[4,5-b]aminoquinolines (5) as novel structurally modified tacrines was obtained by reacting readily accessible precursors (i.e., 3-alky(aryl)-5-amino-1,2,3-triazole-4-carbonitriles (3)) and selected cycloalkanones (4) of five-, six-, and seven-membered rings. We evaluated the AChE and BChE inhibitory activity of the novel modified tacrines 5, and the compound derivatives from cyclohexanone (4b) showed the best AChE and BChE inhibitory activities. Specifically, 1,2,3-triazolo[4,5-b]aminoquinolines 5bb obtained from 3-methyl-carbonitrile (3b) showed the highest AChE (IC50 = 12.01 μM), while 5ib from 3-sulfonamido-carbonitrile (3i) was the most significant inhibitor for BChE (IC50 = 1.78 μM). In general, the inhibitory potency of compound 5 was weaker than the pure tacrine reference, and our findings may help to design and develop novel anticholinesterase drugs based on modified tacrines.

Butyrylcholinesterase inhibitory activity of peptides identified from yellow field pea (Pisum sativum) enzymatic protein hydrolysates

Butyrylcholinesterase (BuChE) is an enzyme implicated in Alzheimer’s disease due to the excessive breakdown of neurotransmitters. The study screened and synthesized de novo peptides derived from yellow field pea as BuChE activity inhibitors. The conformational changes of the enzyme were evaluated to confirm interaction with the peptides, along with mode of inhibition by the peptide and their binding affinity. The result showed no significant conformational changes of the enzyme after interaction with peptides. The catalytic parameters were low indicating strong affinity at low peptide concentrations and maximum velocity (Vmax) decreased with increasing peptide concentration for all the peptides. Peptides with mixed inhibition mode had low docking energy scores suggesting high affinity for BuChE and peptide-enzyme interaction were through catalytic triad and /or peripheral anionic site. Results revealed that peptides derived from yellow field pea protein could be potential inhibitors of BuChE activity and probably effective in AD therapy.

Enzyme inhibitory and antioxidant activities and HPLC quantification of chlorogenic acid in Helichrysum stoechas (L.) Moench and H. stoechas subsp. barrelieri (Ten) Nyman

The inhibitory effects of ethanol (80%) and aqueous extracts of Helichrysum stoechas (L.) Moench and H. stoechas subsp. barrelieri (Ten) Nyman on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), two sister enzymes associated with pathogenesis of Alzheimer's disease (AD), as well as on elastase and collagenase, linked to inflammation and skin aging, were investigated. Simultaneously, antioxidant activity of the extracts was assessed through DPPH radical scavenging activity, ferric reducing antioxidant power (FRAP), and metal-chelating activity assays, since oxidative damage plays a critical role in both AD pathophysiology and skin aging. Total phenol and flavonoid contents in the extracts were spectrophotometrically determined. The highest AChE inhibitory activity (44.60 ± 4.4% at 2000 µg/mL) was found in the ethanol extract of H. stoechas subsp. barrelieri collected from Hatay, and the uppermost BChE inhibitory activity at same concentration was found in the aqueous extract of H. stoechas subsp. barrelieri collected from Izmir (80.24 ± 2.63%, IC50: 38.52 ± 1.41 µg/mL). Both of them inhibited AChE and BChE in a concentration-dependent manner. Nevertheless, none of the extracts from the two plants inhibited the elastase and collagenase. Although both ethanolic and aqueous extracts had significant antioxidant activity in DPPH radical scavenging and FRAP assays, they demonstrated inadequate antioxidant activity in metal-chelating assay. Chlorogenic acid was quantified in the extracts using HPLC. The mentioned two extracts having strong cholinesterase (ChE) inhibition had also the highest chlorogenic acid content. The ethanol extract of H. stoechas (Hatay sample) and the aqueous extract of H. stoechas (Izmir sample) seem to contain promising ChE inhibitors, which deserve further investigation.

Bioassay-guided identification of potential Alzheimer’s disease therapeutic agents from Kaempferol-Enriched fraction of Aframomum melegueta seeds using in vitro and chemoinformatics approaches

Alzheimer's disease (AD) has become a major public health concern and the fifth major cause of death among the aging population globally. In this study, the total phenols and flavonoids contents (TPC and TFC) and in vitro antioxidant actions of the methanol extract and the various fractions of Aframomum melegueta were evaluated using 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, nitric oxide scavenging activity (NO), lipid peroxidation (TBARS) activity and ferric reducing power assay (FRAP). Furthermore, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities of the two most potent fractions were investigated, and the phytochemicals identified in the ethyl acetate fraction, which had the best antioxidant and cholinesterase inhibitory effects were subjected to chemoinformatics studies. The extract and its fraction had high amounts of TPC and TFC. The ethyl acetate fraction exerted the best DPPH, NO, TBARS, and FRAP inhibition with IC50 values of 5.06, 6.58, 2.12, and 88.73 µg/mL, respectively. Interestingly, n-hexane and ethyl acetate fractions inhibited AChE (IC5016.83 and 11.67 µg/mL) and BuChE (IC50 7.54 and 5.21 µg/mL) enzymatic activities more than the standard inhibitor, rivastigmine which had 11.99 and 11.40 µg/mL IC50 values, respectively. A total of 18 compounds were identified in ethyl acetate fraction, and kaempferol was the major component, with 40.01 µg/g (30%). More strikingly, the top-scoring compounds (catechin, and kaempferol) exhibited good binding affinity, and interacted favorably with amino acids residues around and within the active sites of AChE and BuChE and also obeyed drug-likeness rules, and did not show a tendency towards toxicity when placed side by side with rivastigmine which is immunogenic. Thus, A. melegueta seeds contain safe bioactive chemicals, which could be a veritable remedy for managing Alzheimer's and other neurodegenerative diseases.

Quantitative-HPLC-DAD polyphenols analysis, anxiolytic and cognition enhancing potentials of Sorbaria tomentosa Lindl. Rehder

Ethnopharmacological relevanceMedicinal plants of the family Rosaceae have a long history of traditional uses in the management of neurological disorders. Sorbaria tomentosa Lindl. Rehder is composed of antioxidant and neuroprotective polyphenolics. Aims of the studyThe current study was designed to explore phenolics profile via high performance liquid chromatography-photodiode array detector (HPLC-DAD) and validated the neuroprotective and anxiolytic potentials of S. tomentosa by applying in vitro and in vivo approaches. Materials and methodsThe plant crude methanolic extract (St.Crm) and fractions were subjected to HPLC-DAD analysis for qualitative and quantitative assessment of phytochemicals. Samples were screened for in vitro free radicals scavenging assays by using 2,2-diphenylpicrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) along with acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes inhibition assays. For cognitive and anxiolytic studies, mice were subjected to open field, elevated plus maze (EPM), light-dark model, Y-maze, shallow water maze (SWM), and novel object recognition (NOR) tests. ResultsHPLC-DAD analysis revealed the presence of high concentrations of phenolic compounds. For instance, in St.Cr, 21 phenolics were quantified, among which apigenin-7-glucoside (291.6 mg/g), quercetin (122.1 mg/g), quercetin-3-feruloylsophoroside-7-glucoside (52.6 mg/g), quercetin-7-glucoside (51.8 mg/g), ellagic acid (42.7 mg/g), luteolin (45.0 mg/g), kaempferol (40.5 mg/g), 5-feruloylquinic acid (43.7 mg/g) were present in higher concentrations. Likewise, in ethyl acetate fraction (St.Et.Ac), 21 phenolics were identified as 3,5-di-caffeoylquinic acid (177.4 mg/g) and 5-hydroxybenzoylquinic acid (46.9 mg/g) were most abundant phytochemicals. Highly valuable phenolics were also identified in other fractions including butanol (St.Bt), chloroform (St.Chf), and n-hexane (St.Hex). The various fractions exhibited concentration dependent inhibition of free radicals in DPPH and ABTS assays. Potent AChE inhibitory potentials were revealed by the test samples with St.Chf, St.Bt and St.EtAc being the most active having an IC50 of 298.1, 580.1, and 606.47 μg mL−1, respectively. Similarly, St.Chf, St.Bt, St.EtAc and St.Cr exhibited potent BChE inhibitory activity and was observed as 59.14, 54.73, 51.35 and 49.44%, respectively. A significant improvement in the exploratory behavior was observed in open field test and stress/anxiety was relieved effectively at 50-100 mg/kg. Likewise, EPM, light-dark and NOR tests revealed an anxiolytic and memory enhancing behaviors. These effects were further corroborated from the Y-maze and SWM transgenic studies that showed considerable improvement in cognition retention. ConclusionsThese findings concluded that S. tomentosa possessed potential anxiolytic and nootropic efficacies and may have therapeutic potential in neurodegenerative disorders.

Essential Oil and Crude Extracts of Pulicaria arabica (L.) Cass. Aerial Parts: Chemical Composition, Antioxidant Effect, α-Glucosidase, Acetylcholinesterase, and Butyrylcholinesterase Inhibitory Activities

Plants have been an important source of bioactive compounds since ancient times and have recently attracted much attention from researchers and consumers due to the toxic effects of synthetic drugs. Our work aimed to study the chemical composition and some biological activities of the essential oil (EO) and the crude extracts of an endemic plant from Algeria: Pulicaria arabica (L.) Cass. Gas chromatographymass spectrometry (GC/MS) analysis of the EO is conducted for the identification of eight compounds representing 99.6% of the total content. The main compounds were α-Cadinol (35.0%), δ-Cadinene (22.5%), τ-Muurolol (12.6%), and τ-Cadinol (11.7%). The highest contents of total phenolics and flavonoids of the crude extracts were recorded with the methanol extract (185.91 ± 3.11 μg GAE/mg and 62.86 ± 1.98 μg QE/mg of extract, respectively). The antioxidant activity of the EO and the crude extracts was evaluated using six different methods: DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, ABTS (2,2’-azinobis(3-ethylbenzothiazoline)-6-sulfonic)) scavenging activity, the ferric reducing ability of plasma (FRAP), iron chelation, β-carotene bleaching inhibition, and cupric reducing antioxidant capacity (CUPRAC). Acetone and methanol extracts exhibited the highest antioxidant capacity, which can be attributed to their high phenol content. On the contrary, the EO and the hydro-methanolic extract exhibited the highest α-glucosidase inhibitory activity (IC50: 39.74 ± 1.91 and 42.45 ± 4.67 μg/mL, respectively). All the tested extracts were found to be inactive against acetylcholinesterase (AChE) while they showed an interesting inhibitory effect against butyrylcholinesterase (BChE). These findings showed that Pulicaria arabica EO and extracts have important biological activities and might be used in the treatment of diabetes and Alzheimer's disease with antioxidant properties.

Understanding the Chemical Composition and Biological Activities of Different Extracts of Secamone afzelii Leaves: A Potential Source of Bioactive Compounds for the Food Industry.

Secamone afzelii (Roem. & Schult.) K. Schum (family Asclepiadaceae) is a creeping woody climber used to treat ailments in many traditional medicine systems. The present study aims to examine the antioxidant and enzyme inhibition activities of S. afzelii leaf using different compositions of methanol-water mixture as an extraction solvent. The extracts were characterized by HPLC-ESI-MSn in terms of chemical compounds. The in silico results show that compound 23 (quercitrin) has the higher docking scores among the selected substances and the MD simulation revealed that the interactions with the enzymatic pocket are stable over the simulation time and strongly involve the tyrosinase catalytic Cu atoms. All together the results showed that both 80% and 100% methanolic extracts contained significantly (p < 0.05) the highest total phenolics content while the highest content of total flavonoids was significantly (p < 0.05) extracted by 100% methanol. About 26 compounds were tentatively identified by HPLC-ESI-MSn and 6 of them were quantified using standards. Results showed that the extracts were rich in flavonoids with a relatively high abundance of two kaempferol glycosides comprising 60% of quantified compounds. The 100% and 80% methanol extracts recorded significantly (p < 0.05) the highest total antioxidant, DPPH and ABTS activity as well as tyrosinase and ⍺-amylase inhibitory activities. The best significant (p < 0.05) cholinesterase inhibitory activity and reducing capacity of Fe+++ and Cu++ was recorded from the 80% methanolic extract while 100% ethanolic extract gave the highest significant (p < 0.05) butyrylcholinesterase inhibitory activity. The best glucosidase activity was observed in the 50% and 80% methanolic extracts. Although the water extract displayed the least total phenolics and flavonoids content and consequently the lowest antioxidant and enzyme inhibition activity, it displayed significantly (p < 0.05) the highest chelating power. In conclusion, these results demonstrated the richness of S. afzelii leaf as a potential source of bioactive compounds for the food industry, for the preparation of food supplements and functional foods.

Design, synthesis, and biological evaluation of thienopyrimidine derivatives as multifunctional agents against Alzheimer's disease.

A series of 12 S-substituted tetrahydrobenzothienopyrimidines were designed and synthesized based on the donepezil scaffold. All the newly synthesized compounds were evaluated for their acetylcholinesterase (AChE) inhibitory activity and the most active compounds were tested for their butyrylcholinesterase (BuChE) inhibitory activity. Moreover, all the synthesized compounds were evaluated for their inhibitory effects against Aβ aggregation and antioxidant activity using the oxygen radical absorbance capacity method. Compounds 4b, 6b, and 8b displayed the most prominent AChE inhibitory action comparable to donepezil. Compound 6b showed the greatest AChE inhibitory action (IC50 = 0.07 ± 0.003 µM) and the most potent BuChE inhibitory action (IC50 = 0.059 ± 0.004 µM). Furthermore, the three compounds exhibited significant antioxidant activity. Compounds 6b and 8b exerted more inhibitory action on Aβ aggregation than donepezil. The cytotoxic activity of compounds 4b, 6b, and 8b against the WI-38 cell line in comparison with donepezil was examined using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay. The results revealed that compounds 6b and 8b were less cytotixic than donepezil, while compound 4b showed nonsignificant cytotoxicity compared to donepezil. For more insights about the binding patterns of the most promising compounds (4b, 6b, and 8b) with the AChE at molecular levels; molecular docking and molecular dynamics simulations were performed. The densityfunctional theory calculations and absorption, distribution, metabolism, excretion and toxicity properties were described as well. The results highlighted compound 6b, which incorporates a phenylpiperazine moiety coupled to a thienopyrimidone scaffold via two-atom spacer, to be a promising multifunctional therapeutic agent for the treatment of Alzheimer's disease. It is a potent dual AChE and BuChE inhibitor. Furthermore, it had stronger Aβ aggregation inhibitory action than donepezil. Additionally, compound 6b exerted significant antioxidant activity.

Anti-Alzhimer Activity of Bay Leaves in Scopolamine-induced Rat Model

Indian spices always play a great role in Ayurveda and Indian medicine. So, analyzing these plants for their unknown and specialized activity is great. Nearly all the spices have some activity on the brain and CNS. Bay leaves are one of the most common culinary spices from day to day life of Indians. In this study, we have studied bay leaves for their anti-Alzheimer activity which depends on the inhibition of acetylcholine esterase and butyrylcholinesterase. For this study, fi rstly bay leaf oil was extracted by hydrodistillation. Further phytoconstituent like alpha-pinene, terpineol, 1,8-cineol, sabinene, and methyl eugenol were isolated and purifi ed by using TLC, HPLC, and column chromatography followed by fractional distillation. These isolated phytoconstituents were evaluated for their acetylcholinesterase and butyrylcholinesterase inhibition activity in scopolamine-induced rats. This study used galanthamine as a reference, and compared the anti-alzheimer activity of all isolated phytoconstituents.

Sweroside: An iridoid glycoside of potential neuroprotective, antidiabetic, and antioxidant activities supported by molecular docking.

Oxidative stress can be a series burden on human health and may lead to many chronic diseases such as diabetes and neurological disorders. The use of natural products to scavenge the reactive oxygen species has attracted the attention of many researchers, to safely manage these conditions with fewer side effects, in available and cost-effective ways. The current study aimed at the isolation and structure elucidation of sweroside from Schenkia spicata (Gentianaceae) and the evaluation of its antioxidant, antidiabetic, neuroprotective, and enzyme inhibitory potential via in vitro and in silico studies. The antioxidant potential was evaluated by a variety of assays as ABTS, CUPRAC and FRAP, showing values of 0.34 ± 0.08, 21.14 ± 0.43, and 12.32 ± 0.20mg TE/g, respectively, while demonstrating 0.75 ± 0.03mmol TE/g for phosphomolybdenum (PBD) assay. Acetylcholinestrase (AChE), butyrylcholinesterase (BChE) and tyrosinase inhibitory activities were used to evaluate the neuroprotective effect, while the antidiabetic potential was evaluated by measuring α-amylase and glucosidase inhibitory activities. Results revealed that sweroside showed antioxidant and inhibitory effects on the enzymes tested with the exception of AChE. It demonstrated good tyrosinase inhibitory ability with 55.06 ± 1.85mg Kojic acid equivalent /g. Regarding the antidiabetic ability, the compound displayed both amylase and glucosidase (0.10 ± 0.01 and 1.54 ± 0.01mmol Acarbose equivalent/g, respectively) inhibitory activities. Molecular docking studies of sweroside on the active sites of the aforementioned enzymes in addition to NADPH oxidase were performed using Discovery Studio 4.1 software. Results revealed good binding affinities of sweroside to these enzymes mainly through hydrogen bonds and van der Waals interactions. Sweroside can be an important antioxidant and enzyme inhibitory supplement, yet further in vivo and clinical studies are required.

Cholinesterase Inhibitors from an Endophytic Fungus Aspergillus niveus Fv-er401: Metabolomics, Isolation and Molecular Docking

Alzheimer's disease poses a global health concern with unmet demand requiring creative approaches to discover new medications. In this study, we investigated the chemical composition and the anticholinesterase activity of Aspergillus niveus Fv-er401 isolated from Foeniculum vulgare (Apiaceae) roots. Fifty-eight metabolites were identified using UHPLC-MS/MS analysis of the crude extract. The fungal extract showed acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects with IC50 53.44 ± 1.57 and 48.46 ± 0.41 µg/mL, respectively. Two known metabolites were isolated, terrequinone A and citrinin, showing moderate AChE and BuChE inhibitory activity using the Ellman's method (IC50 = 11.10 ± 0.38 µg/mL and 5.06 ± 0.15 µg/mL, respectively for AChE, and IC50 15.63 ± 1.27 µg/mL and 8.02 ± 0.08 µg/mL, respectively for BuChE). As evidenced by molecular docking, the isolated compounds and other structurally related metabolites identified by molecular networking had the required structural features for AChE and BuChE inhibition. Where varioxiranol G (-9.76 and -10.36 kcal/mol), penicitrinol B (-9.50 and -8.02 kcal/mol), dicitrinol A (-8.53 and -7.98 kcal/mol) and asterriquinone CT5 (-8.02 and -8.25 kcal/mol) showed better binding scores as AChE and BuChE inhibitors than the co-crystallized inhibitor (between -7.89 and 7.82 kcal/mol) making them promising candidates for the development of new drugs to treat Alzheimer's.

GC-MS Identification of Cholinesterase Inhibitory and Antioxidant Molecules from Leaves of Cnidoscolus aconitifolius (Miller) I.M. Johnston (Euphorbiaceae)

Backgound: Alzheimer’s disease (AD) is a progressive and fatal neurodegenerative disease, clinically characterized by memory and cognitive dysfunction. AD affects about 35 million people worldwide today and is estimated to nearly double every 20 years. Cnidoscolus aconitifolius (Miller) I.M. Johnston has been reported in Nigerian ethnomedicine as a memory enhancer. There is a lack of scientific evidence to justify the claims. Moreover, there are no effective neurotherapeutic agents available for the treatment of AD; hence the need arises to search for new and more effective agents. Objective: This study aims to evaluate and identify potential molecules with anti-Alzheimer’s and antioxidant potentials from Cnidoscolus aconitifolius leaves. Methods: The air-dried leaves of Cnidoscolus aconitifolius (Miller) I.M. Johnston (PCG/UNN/0267) were extracted using the successive extraction procedure based on increasing the polarity of the eluent in the ascending order of n-hexane, ethyl acetate, and methanol. Phytochemical screening was carried out on the extracts using standard procedures. Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities were done according to Ellman’s method. Eserine was used as standard. Antioxidant potentials were evaluated using standard in vitro chemical analyses. A GC-MS (QP2010SE, SHIDMAZU JAPAN) analysis was done to identify bioactive compounds from the most active fraction. Statistical analyses were performed using one-way ANOVA followed by Dunnett’s Multiple Comparison test at α0.05. Results: Phytochemical analysis revealed the presence of tannins, resins, saponins, flavonoids, phenols, carbohydrates, alkaloids, and terpenoids. Ethyl acetate fraction demonstrated the highest acetylcholinesterase and butyrylcholinesterase inhibitory activity at 1 mg/mL with IC50 values of 0.288 ± 0.00 mg/mL (82.9% inhibition) and 0.440±0.02 mg/mL ((75.4% inhibition), respectively, compared to eserine (IC50=0.050 ± 0.01 mg/mL) for AChE and (IC50=0.049 ± 0.00 mg/mL) for BuChE. Metal (ferrous ion) chelating activity was also high in the ethyl acetate fraction with IC50 value of 0.160 ± 0.00 mg/mL compared to EDTA (IC50 = 0.085 ± 0.00 mg/mL) at 1 mg/mL. Hydroxyl radical scavenging activity was higher in the ethyl acetate fraction (IC50 = 0.352 ± 0.01 mg/mL) when compared to BHT (IC50 = 0.074 ± 0.00 mg/mL) at 1 mg/mL. The pro-anthocyanidin content was also higher in ethyl acetate (6.94 ± 0.16 mg cyanidin/g of sample) compared to other fractions. GC-MS analysis of the most active fraction (ethyl acetate) revealed a total of 56 compounds. The major compounds revealed were: n-Hexadecanoic acid (Area % of 13.45%; Retention time of 14.863), Phytol (Area % of 5.13%; Retention time of 15.864), Octadecanoic acid (Area % of 4.86%; Retention time of 16.211), 9, 12, 15-Octadecatrienoic acid (Z,Z,Z) (Area % of 26.85%; Retention time of 16.09), Squalene (% Area of 2.65%; Retention time of 20.94) and alpha-Tocopheryl acetate (% Area of 1.71%; Retention time of 23.40). Conclusion: C. aconitifolius has the potential to inhibit cholinesterase enzymes involved in the pathology of Alzheimer’s disease. The molecules identified could serve as potential drug leads in managing Alzheimer’s disease.

Withania somnifera L.: Phenolic Compounds Composition and Biological Activity of Commercial Samples and Its Aqueous and Hydromethanolic Extracts.

In the present study, the chemical composition and bioactive properties of commercially available Withania somnifera samples were evaluated. The hydromethanolic and aqueous extracts of the tested samples were analyzed in terms of phenolic compound composition, ascorbic acid content, antioxidant and antibacterial activity, and acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. Polyphenols and ascorbic acid content, as well as the antioxidant activity, were higher in the aqueous extracts than in the hydromethanolic extracts. Generally, aqueous extracts presented higher antioxidant activity than the hydromethanolic ones, especially in the case of 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay. Moreover, higher amounts of phenolic acids and flavonoids were found in the hydromethanolic extracts compared to the aqueous ones. Regarding the antibacterial properties, samples 4, 6, and 10 showed the best overall performance with growth-inhibitory activities against all the examined bacteria strains. Finally, the aqueous and hydromethanolic extracts were the most efficient extracts in terms of AChE and BChE inhibitory activities, respectively. In conclusion, our results indicate that W. somnifera possesses important bioactive properties which could be attributed to the high amounts of phenolic compounds. However, a great variability was recorded in commercially available products, suggesting significant differences in the origin of product and the processing method.

Chemical Composition, and Antioxidant and Cholinesterase Inhibitory Activities of Lindera glauca Fruit Essential Oil and Molecular Docking Studies of Six Selected Compounds

Lindera glauca is a shrub or small tree mostly distributed in China, Japan and Korea. However, reports on the biological activities of Lindera glauca fruit essential oil (LGFEO) are limited. The study on its chemical composition, and antioxidant and cholinesterase inhibitory activities were performed, along with molecular docking of six selected compounds. The LGFEO was extracted by hydro distillation and analyzed by GC-MS and GC-FID. Antioxidant activities of LGFEO were evaluated by three methods with different mechanisms. Acetylcholinesterase and butyrylcholinesterase inhibitory activities of LGFEO were tested. A total of 48 components were identified representing 95.74% of the total composition of LGFEO in which the major compounds were (E)-β-ocimene (41.53%), α-copaene (13.17%), δ-cadinene (6.20%), 3-carene (5.89%) and eucalyptol (3.57%). Weak antioxidant activities of LGFEO in three assays (9.52, 11.36 and 38.98 μmol TE/g, respectively) were observed. LGFEO showed obvious cholinesterase inhibitory activities at the final concentrations of 50 and 20 μg/mL. IC50 values for acetylcholinesterase and butyrylcholinesterase were 46.48 and 34.85 μg/mL, respectively. Molecular docking revealed that geranyl acetate, β-caryophyllene and limonene had lower binding affinities in the range of −7.1 to −6.1 kcal/mol through hydrophobic interactions and hydrogen bond. Six compounds including 3-carene, limonene, eucalyptol, (E)-β-ocimene, geranyl acetate and β-caryophyllene could contribute together to cholinesterase inhibitory activities of LGFEO. This essential oil indicated low potential as natural antioxidant, but it could be potentially used as cholinesterase inhibitor with possible application in food, aromatherapy and pharmaceutical industries.

Chemical composition, antioxidant, anticholinesterase, and alpha-glucosidase activity of Stevia rebaudiana Bertoni extracts cultivated in Algeria

Stevia rebaudiana Bertoni is an endemic species to Paraguay famous for its sweetening power and therapeutic potential for various diseases such as diabetes. The present work evaluates the chemical composition and antioxidant, anticholinesterase, and α-glucosidase activities of S. rebaudiana. The essential oil (EO) of dry Stevia leaves was analyzed by GC/MS and detected the presence of 33 components. Caryophyllene oxide (24.28%), spathulenol (12.31%) and nerolidol (11.8%), and manool oxide (7.36%) were identified as the major ones. The antioxidant activity was evaluated by four complementary methods: DPPH (2,2 diphenylpicrylhydrazyl, ABTS (2, 2’-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid) free radicals scavenging, Cupric reducing antioxidant capacity (CUPRAC), and reducing power. The crude methanolic extract and its fractions showed a variable antioxidant activity and strongly correlated with the content of quantified bioactive compounds. The ethyl acetate fraction showed a very high antioxidant activity close to the tested standards, while EO was active only in the CUPRAC assy. The petrol ether and chloroform fractions showed the best butyrylcholinesterase (BChE) inhibitory activity with IC50 values: 123.7 ± 1.78 and 170.1 ± 0.78 μg/mL, respectively. On the other hand, EO and chloroform revealed a moderate inhibitory activity against acetylcholinesterase (AChE). The in vitro inhibitory effect of the extracts on α-glucosidase indicated that EO effectively inhibited the enzyme with an IC50: 74.9 ± 6.4 µg/mL, better than the standard acarbose. The EO of Stevia has a significant anti-diabetic potential.

Antiparasitic Activity of Hippeastrum Species and Synergistic Interaction between Montanine and Benznidazole against Trypanosoma cruzi.

Hippeastrum species have a wide range of biological properties. In Argentina, this genus comprises ten widely distributed species. To evaluate the antiparasitic and anticholinesterase activities and chemical profiles of seven Argentinean Hippeastrum species and determine the synergism between the major isolated alkaloid-montanine-and benznidazole in anti-Trypanosoma cruzi activity. The antiparasitic activity was evaluated through antiproliferative and viability assays against T. cruzi epimastigotes. Synergism assays were performed using the Chou-Talalay method. AChE and BuChE inhibitory activities were also assessed. The alkaloid composition was obtained using GC-MS analysis. All extracts showed strong growth inhibition of T. cruzi epimastigote proliferation. The extracts from H. aglaiae, H. aulicum, and H. hybrid stand out for their potent and total growth inhibition, which was comparable to benznidazole. The H. reticulatum extract showed strong Acetylcholinesterase (AChE) inhibitory activities, while five species showed moderate Butyrylcholinesterase (BuChE) inhibition. Fifteen alkaloids were identified by means of GC-MS. Regarding the synergism assessment, the highest synergistic effect was obtained from the combination of montanine and benznidazole. Hippeastrum species bulb extracts from Argentina were shown to be a good source of antiparasitic alkaloids and cholinesterase inhibitors. The synergism between montanine and benznidazole emerges as a potential combination for future studies to treat Chagas disease.

Synthesis and Preliminary Biological Evaluation of New Phthalazinone Derivatives with PARP-1 and Cholinesterase Inhibitory Activities

Background: Alzheimer's disease (AD) is the most common brain disorder and remains a major health concern worldwide. Considering the highly complex mechanisms of AD, the search for agents based on a multitarget-directed ligands (MTDLs) strategy to treat AD may be more promising than the traditional “one drug-one target” strategy. Inhibition of Poly (ADP-ribose) polymerases-1 (PARP-1) has a potentially therapeutical effect on AD. Therefore, it is worthy to investigate compounds that target both PARP-1 and cholinesterase, which perhaps produces new agents against AD. Objective: To search for new agents with PARP-1 and cholinesterase inhibitory activities for the treatment of AD. Methods: A series of 21 novel compounds incorporated the respective pharmacophores of two marketed drugs, namely the 4-benzyl phthalazinone moiety of a PARP-1 inhibitor, Olaparib, and the Nbenzylpiperidine moiety of an AChE inhibitor, Donepezil, into one molecule was synthesized. The inhibitory activities of all the synthesized compounds against the enzymes PARP-1, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were evaluated. The binding modes of the most potent compound inside the PARP-1 and the human BChE (hBChE) were investigated by molecular docking. Results: N-((1-(4-fluorobenzyl)piperidin-4-yl)methyl)-2-fluoro-5-((1, 2-dihydro-1-oxophthalazin-4- yl)methyl)benzamide (30) exhibited the most potent inhibitory effect on PARP-1 enzyme (IC50=8.18±2.81nM) and moderate BChE inhibitory activity (IC50=1.63±0.52μM), while its AChE inhibitory activity (IC50=13.48±2.15μM) was weaker than Donepezil (IC50=0.04±0.01μM). Further molecular docking studies revealed that four hydrogen bonds were formed between 30 and PARP-1, meanwhile, 30 interacted with the critical residues His438 and Trp82 of hBChE through hydrogen bonds and hydrophobic interactions, which were necessary for hBChE inhibitory potency. Conclusion: A new compound with potent PARP-1 inhibitory activity and moderate BChE inhibitory activity was obtained, which merited to be further investigated as an anti-AD drug. The studies gave a clue to search for new agents based on PARP-1 and cholinesterase dual-inhibited activities to treat AD.