scholarly journals Inhibitory Effects of Novel 7-Substituted 6-iodo-3-O-Flavonol Glycosides against Cholinesterases and β-secretase Activities, and Evaluation for Potential Antioxidant Properties

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3500 ◽  
Author(s):  
Agbo ◽  
Gildenhuys ◽  
Mphahlele

A series of 7-halogeno- (X = F, Cl, Br) and 7-methoxy-substituted acetylated 6-iodo-3-O-flavonol glycosides were prepared, and evaluated for inhibitory effect in vitro against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. 7-Bromo-2-(4-chlorophenyl)-6-iodo-4H-chromen-4-one-3-O-2,3,4,6-O-tetraacetyl-β-d-glucopyranoside (2k) and 7-bromo-6-iodo-2-(4-methoxyphenyl)-4H-chromen-4-one-3-O-2,3,4,6-O-tetraacetyl-β-d-glucopyranoside (2l) exhibited significant inhibitory effect against AChE activity when compared to the activity of the reference standard, donepezil. Compound 2k was found to be selective against AChE and to exhibit reduced inhibitory effect against BChE activity. 6-Iodo-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one-3-O-2,3,4,6-O-tetraacetyl-β-d-glucopyranoside (2p) was found to exhibit increased activity against BChE, more so than the activity of donepezil. The most active compounds were also evaluated for inhibitory effect against β-secretase activity and for potential radical scavenging activities. The experimental data were complemented with molecular docking (in silico) studies of the most active compounds into the active sites of these enzymes.

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1081
Author(s):  
Matilda Rădulescu ◽  
Călin Jianu ◽  
Alexandra Teodora Lukinich-Gruia ◽  
Marius Mioc ◽  
Alexandra Mioc ◽  
...  

The investigation aimed to study the in vitro and in silico antioxidant properties of Melissa officinalis subsp. officinalis essential oil (MOEO). The chemical composition of MOEO was determined using GC–MS analysis. Among 36 compounds identified in MOEO, the main were beta-cubebene (27.66%), beta-caryophyllene (27.41%), alpha-cadinene (4.72%), caryophyllene oxide (4.09%), and alpha-cadinol (4.07%), respectively. In vitro antioxidant properties of MOEO have been studied in 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging, and inhibition of β-carotene bleaching assays. The half-maximal inhibitory concentration (IC50) for the radical scavenging abilities of ABTS and DPPH were 1.225 ± 0.011 μg/mL and 14.015 ± 0.027 μg/mL, respectively, demonstrating good antioxidant activity. Moreover, MOEO exhibited a strong inhibitory effect (94.031 ± 0.082%) in the β-carotene bleaching assay by neutralizing hydroperoxides, responsible for the oxidation of highly unsaturated β-carotene. Furthermore, molecular docking showed that the MOEO components could exert an in vitro antioxidant activity through xanthine oxidoreductase inhibition. The most active structures are minor MOEO components (approximately 6%), among which the highest affinity for the target protein belongs to carvacrol.


2020 ◽  
Vol 13 (9) ◽  
pp. 240 ◽  
Author(s):  
Cezary Pawlukianiec ◽  
Małgorzata Ewa Gryciuk ◽  
Kacper Maksymilian Mil ◽  
Małgorzata Żendzian-Piotrowska ◽  
Anna Zalewska ◽  
...  

Meloxicam is a non-steroidal anti-inflammatory drug, which has a preferential inhibitory effect to cyclooxyganase-2 (COX-2). Although the drug inhibits prostaglandin synthesis, the exact mechanism of meloxicam is still unknown. This is the first study to assess the effect of meloxicam on protein glyco-oxidation as well as antioxidant activity. For this purpose, we used an in vitro model of oxidized bovine serum albumin (BSA). Glucose, fructose, ribose, glyoxal and methylglyoxal were used as glycating agents, while chloramine T was used as an oxidant. We evaluated the antioxidant properties of albumin (2,2-di-phenyl-1-picrylhydrazyl radical scavenging capacity, total antioxidant capacity and ferric reducing antioxidant power), the intensity of protein glycation (Amadori products, advanced glycation end products) and glyco-oxidation (dityrosine, kynurenine, N-formylkynurenine, tryptophan and amyloid-β) as well as the content of protein oxidation products (advanced oxidation protein products, carbonyl groups and thiol groups). We have demonstrated that meloxicam enhances the antioxidant properties of albumin and prevents the protein oxidation and glycation under the influence of various factors such as sugars, aldehydes and oxidants. Importantly, the antioxidant and anti-glycating activity is similar to that of routinely used antioxidants such as captopril, Trolox, reduced glutathione and lipoic acid as well as protein glycation inhibitors (aminoguanidine). Pleiotropic action of meloxicam may increase the effectiveness of anti-inflammatory treatment in diseases with oxidative stress etiology.


Author(s):  
Stephen Adeniyi Adefegha ◽  
Ganiyu Oboh ◽  
Bathlomew Maduka Okeke

Abstract Objectives This study examined effect of berberine and piperine on neuroprotective potential of neostigmine in the management of neurological disorders. Methods Berberine and neostigmine were weighed (30 g), dissolved in distilled water (30 mL) separately, while, 30 mg piperine was dissolved in ethanol (0.45 mL), made up to 30 mL with distilled water. Antioxidant activities in 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH), 2, 2-azinobis (3-ethylbenzothiazoline-6-sulfonate) radical (ABTS), Fe-chelation, ferric reducing properties (FRAP), nitric oxide (NO) and hydroxyl (OH) radical scavenging abilities and Fe2+, cisplatin and sodium nitroprusside (SNP) induced lipid peroxidation (LPO), and acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and monoamine oxidase (MAO) activities were assessed in vitro. Results The result revealed that tested compounds inhibited enzymes activities dose-dependently. However, berberine (IC50=0.17 mg/mL) had slight higher AChE inhibitory effect than piperine and neostigmine (p<0.05). Also, berberine had the highest BChE inhibitory effect (IC50=0.16 mg/mL) while piperine exhibited the highest MAO inhibitory effect (IC50=0.21 mg/mL). Berberine, piperine and neostigmine exhibited high antioxidant properties and inhibited Fe2+, cisplatin and SNP induced LPO. Conclusions Both alkaloids demonstrated antiradical scavenging ability comparable to neostigmine action against Alzheimer’s disease (AD). The modulatory and antioxidant berberine and piperine properties on these enzymes (AChE, BChE and MAO) could be possible underlying mechanisms in employing these compounds as a complementary therapy in neurodegenerative diseases (NDDs) management.


Author(s):  
Natarajan Kiruthiga ◽  
Govindaraj Saravanan ◽  
Chellappa Selvinthanuja ◽  
Kulandaivel Srinivasan ◽  
Thangavel Sivakumar

Background:: Diabetes mellitus is a challengeable metabolic disorder that leads to a group of complications when HbA1c level not maintained. Most of the existing drugs available in the market in long-term use may lead to serious adverse effects. Hence, current research focuses on drug development for the management of diabetes by synthesizing natural mimicking flavonoid analogues. Objective:: This study focused on the synthesis of flavanone derivatives imitating natural flavonoid core and investigated for their antidiabetic and antioxidant activity, which can help in the development of drug discovery targeting diabetic management. Methods:: The novel 2-phenyl-2,3-dihydro-chromen-4-ones were synthesized from 1,3-diphenyl-prop-2-en-1-one derivatives and characterized using UV, IR, 1HNMR, 13CNMR and mass spectroscopic techniques. Drug target site was determined using graph theoretical analysis and screened the characterized title compounds for their in-silico studies by analyzing their physiochemical properties, ADMET studies, and molecular docking analysis. Antidiabetic and free radical scavenging effects were investigated both by in-vitro (alpha-amylase inhibitory assay) and in-vivo models. Streptozotocin (STZ) induced rats were used as in-vivo models. Results and Discussion:: The α-amylase inhibitory assay showed flavanones with hydroxyl substitution HFA1-HFA7 had significant IC50 values. The test compounds (HFA3-HFA7) were investigated for their antidiabetic activity on STZ induced rats at 40 mg/kg. The blood glucose level and antioxidant enzymes were significantly restored by title compounds (HFA5, HFA4, and HFA6) with an electron-donating group such as hydroxyl, methoxy and thiophenyl group on ring B compared to glibenclamide. Conclusion:: These results suggest that naturally mimicking synthesized flavanone have antidiabetic and antioxidant properties, which can aid in the development of drug towards diabetes management.


Author(s):  
Opeyemi B. Ogunsuyi ◽  
Adedayo O. Ademiluyi ◽  
Ganiyu Oboh

AbstractBackgroundThis study sought to determine the in vitro antioxidant, anti-monoamine oxidase and anticholinesterase properties of extracts (aqueous and alkaloid) of two tropical vegetables from Solanum spp- African eggplant (Solanum macrocarpon L) and black nightshade (Solanum nigrum L) as indices of their neuroprotective properties.MethodsBoth aqueous and alkaloid extracts of African eggplant (AE) and black nightshade (BN) were prepared by solvent extraction according to standard methods. Thereafter, the inhibitory effects of the extracts on monoamine oxidase (MAO) and acetylcholinesterase (AChE) activities, as well as their free radical-scavenging and reducing abilities were assessed. Also, phytochemical analysis for phenols, flavonoids, and alkaloids were carried out.ResultsThe results showed that the extracts inhibited MAO and AChE activities dose dependently, with aqueous extracts showing significantly higher MAO inhibition that the alkaloid extracts from both samples, but in all, BN showed higher MAO inhibitory effect compared to AE; the reverse was however, observed for AChE inhibition. Furthermore, the aqueous extracts showed significantly higher antioxidant properties than the alkaloid extracts, while BN had higher antioxidant properties compared to AN. The phytochemical analysis also showed that BN had significantly higher amount of phenols, flavonoids, and alkaloids than AE.ConclusionsThe anti-monoamine oxidase, anticholinesterase, and antioxidant properties exhibited by extracts from both samples could contribute to their neuroprotective abilities. Thus, these vegetables can be potential sources of functional foods and nutraceuticals in the management of neurodegenerative diseases, especially in the tropics.


2021 ◽  
Vol 11 (5) ◽  
pp. 13333-13346

This study contains the synthesis of the 1-(2-methyl-1,4-benzodioxane)benzimidazole and 2-methyl-1,4-benzodioxane substituted benzimidazolium salts. The benzimidazolium salts were synthesized from the reaction of the 1-(2-methyl-1,4-benzodioxane)benzimidazole and various aryl chlorides. All compounds were characterized using 1H NMR, 13C NMR, FTIR spectroscopy, and elemental analysis techniques. The antioxidant properties of benzimidazolium salts were examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and hydrogen peroxide scavenging ability assays. The compounds showed a moderate inhibitory effect on DPPH radical (The percent inhibition = 29.53-39.75). Also, the compounds exhibited significant H2O2 radical scavenging activity. Antimicrobial activities of the compounds were examined against nine bacterial strains and Candida albicans. All compounds displayed marked antimicrobial activity against tested microorganisms, particularly against Pseudomonas aeruginosa, Listeria monocytogenes, and C. albicans. From the computational perspective, benzimidazolium salts were also optimized at B3LYP / DMol3// DFT level using the Discovery Studio 2020 program. HOMO–LUMO analysis and molecular electrostatic potential surface (MESP) were exerted to examine the effects of benzimidazolium salts' electronic and structural properties.


Author(s):  
Mojgan Azadpour ◽  
Mohammad Mehdi Farajollahi ◽  
Ali Mohammad Varzi ◽  
Pejman Hashemzadeh ◽  
Hossein Mahmoudvand ◽  
...  

Introduction: This study aimed to evaluate the antioxidant property of silymarin (SM) extracted from the seed of Silybum marianum and its anticancer activity on KB and A549 cell lines following 24, 48, and 72 h of treatment. Methods: Ten grams of powdered S. marianum seeds were defatted using n-hexane for 6 hours and then extracted by methanol. The silymarin extracted of extraction components The extracted components of silymarin were measured by spectrophotometric assay and HPLC analysis. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, phenol content, total flavonoid content, and total antioxidant capacity were measured to detect the antioxidant properties of SM. The anticancer activity of the SM on cell lines evaluated by MTT. Results: In HPLC analysis, more than 50% of the peaks were related to silibin A and B. SM was reducedDPPH (the stable free radical) with a 50% inhibitory concentration (IC50) of 6.56 μg/ ml in comparison with butylated hydroxyl toluene (BHT), which indicated an IC50 of ~3.9 μg/ ml.The cytotoxicity effect of SM on the cell lines was studied by MTT assay. The cytotoxicity effect of the extracted silymarin on KB and A549 cell lines was observed up to 80 and 70% at 156 and 78 µg/ml, respectively. The IC50 value of the extracted SM on KB and A549 cell lines after 24 hours of treatment was seen at 555 and 511 µg/ml, respectively. Conclusion: Due to the good antioxidant and anticancer properties of the isolated silymarin, its use as an anticancer drug is suggested.


2020 ◽  
Vol 16 ◽  
Author(s):  
Sajjad Esmaeili ◽  
Nazanin Ghobadi ◽  
Donya Nazari ◽  
Alireza Pourhossein ◽  
Hassan Rasouli ◽  
...  

Background: Curcumin, as the substantial constituent of the turmeric plant (Curcuma longa), plays a significant role in the prevention of various diseases, including diabetes. It possesses ideal structure features as enzyme inhibitor, including a flexible backbone, hydrophobic nature, and several available hydrogen bond (H-bond) donors and acceptors. Objective: The present study aimed at synthesizing several novel curcumin derivatives and further evaluation of these compounds for possible antioxidant and anti-diabetic properties along with inhibitory effect against two carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase, as these enzymes are therapeutic targets for attenuation of postprandial hyperglycemia. Methods: Therefore, curcumin-based pyrido[2,3-d]pyrimidine derivatives were synthesized and identified using an instrumental technique like NMR spectroscopy and then screened for antioxidant and enzyme inhibitory potential. Total antioxidant activity, reducing power assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH• ) radical scavenging activity were done to appraisal the antioxidant potential of these compounds in vitro. Results: Compounds L6-L9 showed higher antioxidant activity while L4, L9, L12 and especially L8 exhibited the best selectivity index (lowest α-amylase/α-glucosidase inhibition ratio). Conclusion: These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index but also to limit the activity of the major reactive oxygen species (ROS) producing pathways.


2021 ◽  
Vol 22 (4) ◽  
pp. 1866
Author(s):  
Fadia S. Youssef ◽  
Elham Alshammari ◽  
Mohamed L. Ashour

Genus Aspergillus represents a widely spread genus of fungi that is highly popular for possessing potent medicinal potential comprising mainly antimicrobial, cytotoxic and antioxidant properties. They are highly attributed to its richness by alkaloids, terpenes, steroids and polyketons. This review aimed to comprehensively explore the diverse alkaloids isolated and identified from different species of genus Aspergillus that were found to be associated with different marine organisms regarding their chemistry and biology. Around 174 alkaloid metabolites were reported, 66 of which showed important biological activities with respect to the tested biological activities mainly comprising antiviral, antibacterial, antifungal, cytotoxic, antioxidant and antifouling activities. Besides, in silico studies on different microbial proteins comprising DNA-gyrase, topoisomerase IV, dihydrofolate reductase, transcriptional regulator TcaR (protein), and aminoglycoside nucleotidyl transferase were done for sixteen alkaloids that showed anti-infective potential for better mechanistic interpretation of their probable mode of action. The inhibitory potential of compounds vs. Angiotensin-Converting Enzyme 2 (ACE2) as an important therapeutic target combating COVID-19 infection and its complication was also examined using molecular docking. Fumigatoside E showed the best fitting within the active sites of all the examined proteins. Thus, Aspergillus species isolated from marine organisms could afford bioactive entities combating infectious diseases.


Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 751
Author(s):  
Marwa Reda Bakkar ◽  
Ahmed Hassan Ibrahim Faraag ◽  
Elham R. S. Soliman ◽  
Manar S. Fouda ◽  
Amir Mahfouz Mokhtar Sarguos ◽  
...  

COVID-19 is a pandemic disease caused by the SARS-CoV-2, which continues to cause global health and economic problems since emerging in China in late 2019. Until now, there are no standard antiviral treatments. Thus, several strategies were adopted to minimize virus transmission, such as social distancing, face covering protection and hand hygiene. Rhamnolipids are glycolipids produced formally by Pseudomonas aeruginosa and as biosurfactants, they were shown to have broad antimicrobial activity. In this study, we investigated the antimicrobial activity of rhamnolipids against selected multidrug resistant bacteria and SARS-CoV-2. Rhamnolipids were produced by growing Pseudomonas aeruginosa strain LeS3 in a new medium formulated from chicken carcass soup. The isolated rhamnolipids were characterized for their molecular composition, formulated into nano-micelles, and the antibacterial activity of the nano-micelles was demonstrated in vitro against both Gram-negative and Gram-positive drug resistant bacteria. In silico studies docking rhamnolipids to structural and non-structural proteins of SARS-CoV-2 was also performed. We demonstrated the efficient and specific interaction of rhamnolipids with the active sites of these proteins. Additionally, the computational studies suggested that rhamnolipids have membrane permeability activity. Thus, the obtained results indicate that SARS-CoV-2 could be another target of rhamnolipids and could find utility in the fight against COVID-19, a future perspective to be considered.


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