Inhibition Of Enzyme Acetylcholinesterase Research Articles

GINGER LOADED CHITOSAN NANOPARTICLES FOR THE MANAGEMENT OF 3–NITROPROPIONIC ACID-INDUCED HUNTINGTON’S DISEASE-LIKE SYMPTOMS IN MALE WISTAR RATS

Objective: The purpose of this research work is to enhance bioavailability and brain delivery of ginger through the development of ginger-loaded chitosan nanoparticles and evaluation of its neuroprotective potential against 3-Nitropropionic acid (3-NP) induced Huntington’s Disease model rats. Methods: Ginger-loaded chitosan nanoparticles were developed as five different formulations (F1-F5) by the ionic gelation method. Based on their release, formulations F1 and F3 were chosen for physicochemical characterization. The neuroprotective activity of formulations F1 and F3 were evaluated by behavioural (Neurological scoring, Hanging wire test, Elevated plus maze test), biochemical (estimation of lipid peroxidation, glutathione, protein, superoxide dismutase, catalase) and neurochemical (estimation of acetylcholine esterase inhibition) tests in comparison with ginger extract in Huntington’s Disease (HD) model rats. Results: Formulations F1 and F3 showed almost similar and significant controlled release. Formulation F1 showed spherical nanoparticles with optimum size range and negative zeta potential. The behavioural assessment revealed that there was an improvement in gait, movement, grip strength and memory in ginger-loaded chitosan nanoformulations administered to rats than ginger extract administered rats. Biochemical and neurochemical analyses also proved that ginger-loaded chitosan nanoformulations had greatly lowered the oxidative stress parameters such as malondialdehyde and protein carbonyls in comparison with ginger extract (p<0.05). The ginger nanoformulations had highly increased the activity of antioxidant enzymes such as superoxide dismutase, glutathione and catalase by reducing the formation of free radicals than ginger extract (p<0.05). The memory and cognition of ginger nanoformulations administered Wistar rats had highly improved than ginger extract administered Wistar rats (p<0.05 due to inhibition of acetylcholine esterase enzyme). Conclusion: The current study indicated that ginger-loaded chitosan nanoparticles have a superior neuroprotective effect than their extract due to their nano size, which facilitates their entry across the blood-brain barrier and eventually improves the bioavailability of ginger.

Potentiality of some botanical extracts as biopesticides against the maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae)

Laboratory studies were conducted to investigate the efficacy of some botanicals in the management of Sitophilus zeamais Motsch infesting stored sorghum. The selected plant species were Euphorbia balsamifera Aiton, Lawsonia inermis L. and Mitracarpus hirtus L. Chloroform leaf extracts of the botanicals applied at 6.25, 12.50, 25.00, 50.00 and 100.00 mg ml-1 were used to determine their effect on adult survival, the concentration of total body protein and inhibition of acetylcholinesterase enzyme (AChE) activity in the weevils at 30 ± 2 oC and 70 ± 5% R.H. The botanicals resulted in adult mortalities ranging from 10.00 ± 0.00 to 90.00 ± 5.77%, reduced body protein and significantly inhibited the activity of AChE in S. zeamais. The botanicals tested could serve as biopesticides in the management of S. zeamais infesting sorghum in the storage.

Doxycycline: An Antibiotic Attenuates Oxidant Stress, Perturbation of Lipid Metabolites, and Antioxidants against Vanadium Toxicity in Rat Hepatocytes

Background The liver is target following exposure to pentavalent vanadium (V5+). Doxycycline is an antioxidant that prevents the progression of disease through inhibition of lipid peroxidation. Aim The present study was designed to evaluate the protective effects of doxycycline against vanadium-induced hepatoxicity. Methods Sixty two male Sprague-Dawley rats (250–300 g) were equally divided into the following four groups: control group (received 0.2 mL of physiological saline), doxycycline control group (received 4 mg/kg body weight on day 1 and 2 mg/kg body weight daily thereafter), vanadium group (received elemental vanadium 1.5 mg/kg-body weight in distilled water), and concomitantly treated group (doxycycline + vanadium) received (doxycycline 4 mg/kg body weight on day 1 and 2 mg/kg body weight thereafter + vanadium 1.5 mg/kg body weight), all given orally for 10 consecutive days. The rats were sacrificed by decapitation 24 hours after the last dose. The liver was removed rapidly and processed for the evaluation of metabolic variables: phospholipids, cholesterol, cerebrosides, gangliosides, reduced glutathione (GSH), vitamin C, calcium, acetylcholinesterase enzyme, and lipid peroxidation. Results Vanadium administration significantly reduced (−60 g) the body weight and significantly increased (+28%) the relative liver weight compared with controls. The rats exhibited neurological function deficits. Vanadium administration decreased the concentrations of metabolic variables compared with controls, cerebrosides (−50%), cholesterol (−39%), phospholipids (−18%), GSH (−45%), and inhibited acetylcholinesterase enzyme (–48%). Gangliosides (+ 38%), vitamin C (+ 20%), and calcium (+ 80%) were increased together with an enhancement (+64%) in lipid peroxidation. The combined treatment (vanadium and doxycycline) significantly increased (+25 g) the body weight and relative liver weight of rat was significantly reduced (+5%) compared with vanadium administered group. The levels of metabolic variables were significantly reversed in this group in the following order: cholesterol (+17%), phospholipids (+7%), vitamin C (−14%), acetylcholinesterase enzyme activity (−27%) together with inhibition (−16%) of lipid peroxidation. All levels were (p < 0.05). Doxycycline presented no effect on the levels of GSH, cerebrosides, and gangliosides. Conclusion Results of this study suggested vanadium-induced oxidation of lipids and sphingolipids in hepatocytes and much of GSH was consumed against high production of reactive oxygen species. Doxycycline protected against vanadium-induced oxidative damage that could be attributed to its free radical scavenging effects on membrane-bound lipids and acetylcholinesterase enzyme.

Recent Advances in Approved, Withdrawn, Experimental and Investigational Drugs in Clinical Trials for Alzheimer’s disease

Alzheimer’s disease (AD) is an irreversible, chronic degenerative disease that slowly destroys memory and thinking skills, and eventually destroys the ability to carry out the simplest of day-to-day routine tasks. This disease is characterised by loss of neurons and synapses in the cerebral cortex and certain subcortical regions. Presence of beta-amyloid (Aβ) plaques and neurofibrillary tangles (NFTs) in brains of the affected patients are the distinguishable characteristics of this disease. Currently, no treatment is available to stop or reverse progression of AD, though it may temporarily improve symptoms. There are four USFDA approved drugs which are helpful for symptomatic treatment in AD namely Donepezil, Rivastigmine, Galantamine and Memantine. Memantine functions as an NMDA receptor antagonist, whereas the other three drugs act by inhibiting the acetylcholinesterase enzyme (AChE) resulting in an increase in the levels of acetylcholine (ACh) in the body. In the past decades, many advancements in the current drugs as well as the experimental drugs for AD have been made and these involve structural modifications and mechanistic improvements to increase the capacity of the molecules to cross the blood brain barrier (BBB). Synthesis of 2-acetylphenol-donepezil hybrids is an example of an approach which was adopted based on MultiTarget Directed Ligand (MTDL) strategy. Recently, synthesis of salicylanilide N-alkyl carbamates was carried out and these were observed to possess higher AChE inhibiting capacity than Rivastigmine. Memogain is an inactive prodrug of galantamine which has shown improved effectiveness, fewer side effects and due to its lipophilic nature is said to penetrate the BBB where it gets cleaved into active galantamine. Huperzine A is another highly selective AChE inhibitor and is approved for use only in China though not by USFDA. Tacrine and Huperazine A were combined together to form a hybrid molecule Huprine X, which is said to possess not only potency but also higher selectivity for AChE inhibition alongside anti-Aβ properties.

Inhibitory potential of nitrogen, oxygen and sulfur containing heterocyclic scaffolds against acetylcholinesterase and butyrylcholinesterase.

Heterocycles are the key structures in organic chemistry owing to their immense applications in the biological, chemical, and pharmaceutical fields. Heterocyclic compounds perform various noteworthy functions in nature, medication, innovation etc. Most frequently, pure nitrogen heterocycles or various positional combinations of nitrogen, oxygen, and sulfur atoms in five or six-membered rings can be found. Inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes is a popular strategy for the management of numerous mental diseases. In this context, cholinesterase inhibitors are utilized to relieve the symptoms of neurological illnesses like dementia and Alzheimer's disease (AD). The present review focuses on various heterocyclic scaffolds and their role in designing and developing new potential AChE and BChE inhibitors to treat AD. Moreover, a detailed structure–activity relationship (SAR) has been established for the future discovery of novel drugs for the treatment of AD. Most of the heterocyclic motifs have been used in the design of new potent cholinesterase inhibitors. In this regard, this review is an endeavor to summarize the biological and chemical studies over the past decade (2010–2022) describing the pursuit of new N, O and S containing heterocycles which can offer a rich supply of promising AChE and BChE inhibitory activities.

Comprehensive evaluation of Reseda lutea L. (Wild Mignonette) and 7 isolated flavonol glycosides: determination of antioxidant activity, anti-Alzheimer, antidiabetic and cytotoxic effects with in vitro and in silico methods.

In this study, anticholinergic, antidiabetic, antioxidant and cytotoxic activities of Reseda lutea L. (R. lutea) were determined. Ethanol extracts of R. lutea (EERL) and water extract of R. lutea (WERL) were prepared for biochemical analysis. The antioxidant capacities of EERL and WERL were evaluated with 6 different methods. In addition, acetylcholinesterase (AChE), α-amylase and α-glycosidase enzyme inhibition by EERL were measured. According to the results, EERL exhibited high inhibition effects against α-amylase, α-glycosidase and AChE enzymes. The IC50 values of EERL against AChE (2.21 μg/mL), α-glycosidase (1.38 μg/mL), and α-amylase (0.11 μg/mL) were determined. Also, high cytotoxic effect of EERL was observed on human lung cancer cell lines (A549) with an IC50 value of 3.58 ± 1.10 μg/mL. The affinities of 7 kaempferol and isorhamnetin rhamnopyranoside molecules, previously isolated from R. lutea, for AChE, α-amylase and, α-glycosidase were determined by molecular docking studies. Molecular docking results supported the in vitro results of the study. The results showed that the aerial parts of R. lutea have effective antioxidant, anticholinergic, antidiabetic and cytotoxic activities. This research will form the basis for further studies about R. lutea usage for drug development.

Synthesis and in vitro α-glucosidase and cholinesterases inhibitory actions of water-soluble metallophthalocyanines bearing ({6-[3-(diethylamino)phenoxy]hexyl}oxy groups.

In this paper, we have prepared peripherally tetra-({6-[3-(diethylamino)phenoxy]hexyl}oxy substituted cobalt(II), copper(II), manganese(III) phthalocyanines (3, 4, 5) and their water-soluble derivatives (3a, 4a, 5a). Then, in vitro α-glucosidase and cholinesterases inhibitory actions of the water-soluble 3a, 4a, 5a were examined using spectrophotometric methods. 4a had the highest inhibitory effects among the tested compounds against α-glucosidase due to IC50 values. 4a and 5a had 40 fold higher inhibitory effects than the positive control. For cholinesterases, the compounds showed significant inhibitory actions that of galantamine which was used as a positive control. According to the SI value, 3a inhibited acetylcholinesterase enzyme selectively. In kinetic studies, 4a was a mixed inhibitor for α-glucosidase, 3a was a competitive inhibitor for AChE, and 4a was a mixed inhibitor for BuChE. The therapeutic potential of these compounds has been demonstrated by in vitro studies, but these data should be supported by further studies.

Synthesis, in vitro biological screening and docking study of benzo[d]oxazole bis Schiff base derivatives as a potent anti-Alzheimer agent

We have synthesized benzo[d]oxazole derivatives (1–21) through a multistep reaction. Alteration in the structure of derivatives was brought in the last step via using various substituted aromatic aldehydes. In search of an anti-Alzheimer agent, all derivatives were evaluated against acetylcholinesterase and butyrylcholinesterase enzyme under positive control of standard drug donepezil (IC50 = 0.016 ± 0.12 and 4.5 ± 0.11 µM) respectively. In case of acetylcholinesterase enzyme inhibition, derivatives 8, 9 and 18 (IC50 = 0.50 ± 0.01, 0.90 ± 0.05 and 0.3 ± 0.05 µM) showed very promising inhibitory potentials. While in case of butyrylcholinesterase enzyme inhibition, most of the derivatives like 6, 8, 9, 13, 15, 18 and 19 (IC50 = 2.70 ± 0.10, 2.60 ± 0.10, 2.20 ± 0.10, 4.25 ± 0.10, 3.30 ± 0.10, 0.96 ± 0.05 and 3.20 ± 0.10 µM) displayed better inhibitory potential than donepezil. Moreover, derivative 18 is the most potent one among the series in both inhibitions. The binding interaction of derivatives with the active gorge of the enzyme was confirmed via a docking study. Furthermore, the binding interaction between derivatives and the active site of enzymes was correlated through the SAR study. Structures of all derivatives were confirmed through spectroscopic techniques such as 1H-NMR, 13C-NMR and HREI-MS, respectively. Communicated by Ramaswamy H. Sarma

Pharmacological Evaluation of Green Chilli in Alzheimer’s Disease

Pharmacognosy Research,2022,14,1,61-70.DOI:10.5530/pres.14.1.10Published:December 2021Type:Research ArticleAuthors:Pandurangan Perumal, and Desmond Yong Hua Chong Author(s) affiliations:Pandurangan Perumal1,*Desmond Yong Hua Chong2 1Department of Pharmaceutical Analysis, Sree Vidyanikethan College of Pharmacy, Tirupathi, Andrapradesh, INDIA. 1Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Asian Institute of Medicine Science Technology (AIMST ) University, Bedong, Kedah DarulAman, MALAYSIA. Abstract:Background: Green chilli pepper (Capsicum annum L. car frutescens) is popular as a spice used in many cuisines across the world. Capsaicin, as the pharmacologically active composition of chilli pepper, has been shown to possess antioxidant, local analgesic, and hypoglycemic effects according to many studies conducted on the red chilli pepper. However, there is no data associated with the role of green chilli peppers in Alzheimer’s disease (AD) caused by capsaicin, rather than red chilli peppers. Objectives: To evaluate the acetylcholinesterase (AChE) and beta-secretase enzyme inhibition of ethanolic extract of Capsicum frutescens (EECF) or known as green chilli in in-vitro manner. Materials and Methods: Extraction was carried out on the fruits of Capsicum frutescens with ethanol. Its ethanolic extract in different concentrations was applied as the analyte to test its anti-acetylcholinesterase activity and enzymatic inhibitory action on the beta-secretase. Donepezil with various concentrations was also prepared as the control set for comparison of effect with EECF. Both the analytes were tested using the QuantiChromTM and BACE-1 FRET assay kits, for evaluation of inhibition activity against acetylcholinesterase and BACE-1 respectively. Results: There is significant increase in the percentage of inhibition against acetylcholinesterase and BACE-1 when tested with increased concentration of EECF. Compared to inhibitory effects by EECF, donepezil exhibited higher values of IC50 against both the assayed key enzymes, though also demonstrated vital inhibitory actions in both assays. EECF also showed higher potency in controlling AD progression in terms of inhibition against acetylcholinesterase, shown by IC50 value for the acetylcholinesterase, if compared to IC50 value for BACE-1. Conclusion: Green chilli or EECF has potential to have inhibitory action on acetylcholinesterase and beta-secretase enzymes in patients with AD, but limited to optimum concentration or dose. Keywords:Acetylcholinesterase, Alzheimer’s disease, Betasecretase, Capsaicin., Green chilliView:PDF (344.54 KB) Full Text

Synthesis of Spirooxindole Analogs Tethered Pyrazole Scaffold as Acetylcholinesterase Inhibitors

AbstractA new series of spirooxindole analogs tethered pyrazole scaffold constructed via [3+2] cycloaddition (32CA) reaction starting from the new chalcone named (E)‐3‐(5‐chloro‐3‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)‐1‐(5‐methyl‐1‐phenyl‐1H‐pyrazol‐4‐yl)prop‐2‐en‐1‐one which confirmed by single crystal X‐ray diffraction analysis. Synthesized spirooxindole analogs were evaluated for their neuroprotection through the inhibition of acetylcholine esterase enzyme using Ellman's method. Compounds 9 w, 9 e and 9 x showed the strongest acetylcholine esterase inhibition (AChEI) with IC50 values of 5.7, 7.8 and 8.3 μM, respectively. Obviously, the incorporation of NO2 group into isatin 5th position and N‐methylglycine (sarcosine) play a crucial role for the activity which lead to compound 9 w had the most potent inhibitory activity with IC50 value of 5.7 μM. Molecular docking was used to study their interaction with the active site of hAChE. These 32CA reactions takes place via a one‐step mechanism with a high polar character as a consequence of the supernucleophilic character of azomethine yildes and the strong electrophilic character of ethylenes.

Temporal exposure to malathion: Biochemical changes in the Amazonian fish tambaqui, Colossoma macropomum.

The main toxicity mechanism of organophosphate insecticides such as malathion is the acetylcholinesterase enzyme inhibition. However, fish responses to organophosphates may vary depending on the activation of different defense mechanisms as well as the length of exposure. As such, the evaluation of acetylcholinesterase activity, in combination with the evaluation of biotransformation and antioxidants enzymes levels, is useful for indicating damage in fish exposed to this insecticide. Moreover, evaluating mitochondrial activity might evidence how the hierarchic responses occur in relation to the length of time that the fish is exposed. Therefore, the aim of our study is to evaluate whether the length of exposure to malathion differentially affects the biochemical responses of tambaqui. Our hypothesis is that the physiological alterations due to exposure are time dependent. Fish were exposed to sublethal concentrations of the insecticide during 6, 12, 24, 36, and 48h. Contrary to expectations, there was no acetylcholinesterase activity inhibition during the experiment, which indicates an absence of neurotoxicity. Phase II biotransformation mechanism was activated early, especially in the liver. Oxidative damage was evident in the first hours of exposure and was concurrent with the activation of antioxidant enzymes. Mitochondrial bioenergetics were differentially affected by the length of exposure. The data suggest that the tambaqui regulates mitochondrial respiration differently over time, seeking to maintain homeostasis and ATP demand, and ensures the activation of response mechanisms, thus minimizing oxidative damage and avoiding the neurotoxicity of malathion.

Novel tetrakis–phthalocyanines bearing pyrimidine derivative: crystal XRD analysis, enzyme inhibition, molecular docking, and anticancer effects

In this study, the novel 4-(4-Aminopyrimidin-2-ylthio) phthalonitrile (1) as starting material was synthesized and its 3D structure was verified by the single crystal X-ray diffraction experiment. Then, its peripherally tetra-substituted phthalocyanines (2,3) and the methylated derivatives (2a,3a) containing pyrimidine derivative were synthesized. All these newly synthesized compounds were characterized with various spectroscopic methods such as UV–Vis, FT-IR, 1H-NMR, 13C-NMR and MALDI-TOF MS by obtaining satisfactory results. In addition, these novel phthalocyanines effectively inhibited acetylcholinesterase enzyme, with K i values in the range of 10.43 ± 2.38 to 41.70 ± 9.32 µM. For the related enzyme, the IC50 values were obtained in the range of 11.68 to 44.28 µM. For α-glycosidase enzyme the most effective K i values of (3a) and (2) were with K i values of 92.87 ± 10.70 and 95.18 ± 17.83 µM, respectively. Indeed, the most potent phthalocyanines against both enzymes were recorded for the purpose of investigating interaction modes of these complexes in the active site of the target enzyme. The cytotoxicity potential of these phthalocyanines against human breast, colon, and prostate cancers demonstrated that these compounds had normal cytotoxic effects. Communicated by Ramaswamy H. Sarma

Antimicrobial, Cytotoxic, and α-Glucosidase Inhibitory Potentials Using the One Strain Many Compounds Technique for Red Sea Soft Corals Associated Fungi’ Secondary Metabolites and Chemical Composition Correlations

Aspergillus unguis SPMD-EGY (A. unguis) and Aspergillus sp. 2C1-EGY (Aspergillus sp.) were isolated from the soft corals Sinularia and Lobophyton sp in the Hurghada coast, Red Sea, Egypt. One strain many compounds (OSMAC) was applied to trigger fungal silent biosynthetic genes. The results revealed that the A. unguis static filtrate extracts (St F) of all tested media exhibited the highest antimicrobial activity (inhibition zones 18.5-30.5 mm) against S. aureus, P. aeruginosa, and C. albicans. The A. unguis shake cell extracts of media A and C exhibited the highest α-glucosidase inhibitory activity (Sh Cell, 78 and 82 %). A high degree of acetylcholinesterase enzyme inhibition was obtained from A. unguis (Sh F, 61-66 %) shake filtrate extracts. The A. unguis extracts (A St F and D St Cell) demonstrated the highest cytotoxic activity against cancer cells, namely, HepG2, MCF-7, and HCT-116 (%I: 62-95; IC50: 7.9-90.8 µg/mL). The A. unguis extracts (A St F&D St F) exhibited high cytotoxic activities against HCT116 cancer spheroids compared with cisplatin (42.2 % and 51 %, respectively, vs 32.6 % for cisplatin). The biological activities of the extracts were due to the presence of various secondary metabolites detected by GC/MS analysis. Further pharmacological studies may lead to the isolation of new antitumor compounds besides the prospective antimicrobial and α-glucosidase inhibition capacity of the active extracts.

Synthesis of fluorescent carbon quantum dots from Jatropha fruits and their application in fluorometric sensor for the detection of chlorpyrifos

In this study, we have synthesized fluorescent carbon quantum dots (J-CQDs) from Jatropha fruit by using a one-pot hydrothermal approach, for the first time. The as-synthesized J–CQDs exhibited bright blue fluorescence emission with a high quantum yield of 13.7 %. Furthermore, the synthesized fluorescent J-CQDs have been used as a fluorometric sensor for the detection of pesticides. The sensing of pesticides is based on the irreversible catalytic inhibition of acetylcholinesterase (AChE) enzyme with a controlled fluorescence quenching process. The thiocholine was mainly triggered by the decomposition of DTNB to form yellow-colored TNBA. Further, TNBA gradually quenched the fluorescence emission spectra of added J-CQDs via dynamic quenching. The catalytic activity of AChE was inhibited in the presence of OPs, leading to the recovery of the fluorescence signal. Thus, a sensitive and selective nanoprobe was designed for the sensing of OPs (chlorpyrifos) along with a detection limit 2.7 ng/mL. Apart from this, the proposed sensing method has been successfully applied for pesticide detection in environmental and agricultural samples with acceptable recovery. Thus, the delivered result suggests that our probe is simple in design, having a short reaction time, and could be proficiently used in further analytical and environmental applications in the future.

Polystyrene Microplastics Exposure: An Insight into Multiple Organ Histological Alterations, Oxidative Stress and Neurotoxicity in Javanese Medaka Fish (Oryzias javanicus Bleeker, 1854).

Microplastics (MPs) have become pollutants of concern due to their unknown human health effect and negative impact on terrestrial and aquatic ecosystems. There is increasing number of experimental research on MPs globally with its effects not fully understood; recent animal studies explore its effects on the intestines, yet on other vital organs. Javanese medaka fish was exposed to polystyrene microplastics (PS-MPs) beads for a period of 21 days. Histological alterations, intestinal oxidative stress, permeability and neurotoxicity were evaluated. Significant inflammatory changes and tissue damage were observed in the intestine, liver and kidney. Intestinal oxidative stress and permeability were found to be significantly increased. In the brain, neurotoxicity characterised by a significant induction of oxidative stress, lipid peroxidation and the inhibition of acetylcholinesterase enzyme were elucidated. This study provided an insight into the multiple organ effect of microplastics exposure, necessitating further exploration and identification of biomarkers to be utilised for biomonitoring population at risk in the future.

Pharmacokinetics, Mechanism, and Docking Study of Antioxidant Aryl‐Bisthiourea Derivatives for Alzheimer's Disease

AbstractNovel aryl‐bisthiourea derivatives (3 a–3 j) were synthesized by a two‐step route for the study of free‐radical scavenging property and acetylcholinesterase enzyme (AChE) inhibition study. The effect of the electronic environment on the aryl structure of ArBTU on the AChE inhibition was studied. Lineweaver‐Burk plot was used for kinetic study of inhibition of AChE by using ArBTU derivatives which exhibited very good bioactivity of inhibition against acetylcholinesterase enzyme. Central Nervous System (CNS) permeability and the Blood‐Brain Barrier values of all ArBTU derivatives (3 a–3 j) were also similar to the reference value (>−2 logPS< −3 and >−0.3 log BB< −1), respectively. The molecular docking study of derivative 3 g presented a very good interactions with tested protein. The mechanism of AChE inhibition was found from the kinetic studies of novel ArBTU derivatives. A pharmacokinetic study of AChE inhibition was also evaluated. ArBTU derivatives (3 a–3 j) exhibited the best lead‐like potential. Molecular docking study described the binding ability of the highly effective derivative 3 g with the acetylcholinesterase enzyme.

HPLC-Analysis, Biological Activities and Characterization of Action Mode of Saudi Marrubium vulgare against Foodborne Diseases Bacteria.

The present study aims to evaluate the chemical composition, metabolites secondary and pharmacology activities of methanolic extract of Marrubium vulgare collected from King Saudi Arabia. Moreover, the primary mode of action of the tested extract was studied here for the first time against E. coli and L. monocytogenes. HPLC analysis shows that the major components in the tested extract are luteolin-7-O-d-glucoside, ferulic acid and premarrubiin. Obtained data demonstrated that the investigated extract was richer in phenol (26.8 ± 0.01 mg/GAE g) than in flavonoids (0.61 ± 0.05 mg EC/mL). In addition, the methanolic extract showed an important antioxidant capacity against the DPPH (IC50 = 35 ± 0.01 µg/mL) and ABTS (IC50 = 25 ± 0.2 µg/mL) radical scavenging and a strong inhibition of acetylcholinesterase enzyme with an IC50 value corresponding to 0.4 mg/mL. The antibacterial activity demonstrated that the evaluated extract had significant activity against both Gram-positive and Gram-negative bacteria. The effect of time on cell integrity on E. coli and L. monocytogenes determined by time–kill and bacteriolysis tests showed that the M. vulgare extract reduced the viability of both strains after 8 and 10 h and had a bacteriolytic effect against two different categories of bacteria, Gram-positive and negative, which are not of the same potency. Based on obtained data, it can be concluded that Saudi M. vulgare has a high pharmacological importance and can be used in preparation of food or drugs.

Synthesis, kinetics and biological assay of some novel aryl bis-thioureas: A potential drug candidates for Alzheimer's disease

A new series of bis-thioureas (4a-4j) was synthesized and characterized through spectroscopic and elemental analysis. The synthesized compounds 4a-4j were subjected to acetylcholinesterase enzyme (AChE) inhibition activity and free radical scavenging activity. The results of AChE inhibition assay were found to be active in inhibiting the target enzyme with different IC50 values. Among all derivatives, the 4 g showed highly potent inhibition potential against AChE enzyme with IC50 value of 0.1761±0.00768 µM, which is several times better than the reference inhibitor neostigmine methylsulfate IC50 2.469±0.069 µM. The initial structure-activity relationship (SAR) of 4 g revealed dual hydrogen bonding ability (donor and acceptor). Moreover, the electronic environment around the aromatic ring also greatly influenced the enzyme inhibition of AChE. To further explore the newly synthesized AChE inhibitors, kinetic studies were carried out to determine the mode of inhibition and it was found to be competitive inhibition. Pharmacokinetic predictions (ADMET parameters) were also evaluated and compounds showed good lead-like potential with little hepatotoxic and no skin-sensitive effects. The molecular docking studies delineated the binding affinity of the ligands with target protein and showed docking scores in the range of -10.3 to -7.6 kcal/mol.

Neuroprotective effects of Bhilawanol and Anacardic acid during glutamate-induced neurotoxicity

Bhilawanol (Bh) and anacardic acid (AA) are two lipid-soluble compounds mostly found in the nut of Semecarpus anacardium (SA). This herb has many medicinal properties including enhancing learning and memory, yet its active compounds have not been studied for neuroprotective effects. We investigated the neuroprotective effects of Bh and AA against glutamate induced cell death in the adrenal pheochromocytoma cell line of rats (PC12 cells). Cell viability, toxicity and calcium influx were determined by MTT assay, LDH release assay and Fluo-3 imaging while apoptosis was assayed by caspase-3 and Bcl-2 gene expression. Our results showed that Bh and AA treatments significantly increased cell viability, reduced cell toxicity and calcium influx in PC12 cells in addition to suppressing the reactive oxygen species. Furthermore, AA treatment decreased caspase-3 expression level whereas both Bh and AA enhanced the expression of anti-apoptotic gene Bcl-2 in PC12 cells. Both compounds potently inhibited acetylcholinesterase enzyme (AChE) in a dose and time dependent manner. These findings suggest that the traditional use of SA may be explained on the basis of both Bh and AA showing neuroprotective potential due to their effects on enhancing cell viability, reducing cell toxicity most probably by reducing excessive calcium influx and suppression of ROS as well as by decreasing the expression of proapoptotic caspase 3 gene and increasing the expression of antiapoptotic gene Bcl2. Traditional use in enhancing learning and memory was justified in part by inhibition of AChE.

Larvicidal activity and in silico studies of cinnamic acid derivatives against Aedes aegypti (Diptera: Culicidae)

Cinnamic acid derivatives (CAD's) represent a great alternative in the search for insecticides against Aedes aegypti mosquitoes since they have antimicrobial and insecticide properties. Ae. aegypti is responsible for transmitting Dengue, Chikungunya, and Zika viruses, among other arboviruses associated with morbimortality, especially in developing countries. In view of this, in vitro analyses of n-substituted cinnamic acids and esters were performed upon 4th instar larvae (L4) of Ae. aegypti, as well as, molecular docking studies to propose a potential biological target towards this mosquitoes species. The larvicide assays proved that n-substituted ethyl cinnamates showed a more pronounced activity than their corresponding acids, in which p-chlorocinnamate (3j) presented a LC50 value of 8.3 µg/mL. Thusly, external morphologic alterations (rigid and elongated body, curved bowel, and translucent or darkened anal papillae) of mosquitoes’ group exposed to compound 3j, were observed by microscopy. In addition, an analytical method was developed for the quantification of the most promising analog by using high-performance liquid chromatography with UV detection (HPLC-UV). Molecular docking studies suggested that the larvicide action is associated with inhibition of acetylcholinesterase (AChE) enzyme. Therefore, expanding the larvicidal study with the cinnamic acid derivatives against the vector Ae. aegypti is important for finding search for more effective larvicides and with lower toxicity, since they have already shown good larvicidal properties against Ae. aegypti.