Ilhame BOURAIS - Academia.edu (original) (raw)

Papers by Ilhame BOURAIS

Records of natural produc, Feb 21, 2024

Sensors, Jan 9, 2018

A large number of enzyme inhibitors are used as drugs to treat several diseases such as gout, dia... more A large number of enzyme inhibitors are used as drugs to treat several diseases such as gout, diabetes, AIDS, depression, Parkinson's and Alzheimer's diseases. Electrochemical biosensors based on enzyme inhibition are useful devices for an easy, fast and environment friendly monitoring of inhibitors like drugs. In the last decades, electrochemical biosensors have shown great potentials in the detection of different drugs like neostigmine, ketoconazole, donepezil, allopurinol and many others. They attracted increasing attention due to the advantage of being high sensitive and accurate analytical tools, able to reach low detection limits and the possibility to be performed on real samples. This review will spotlight the research conducted in the past 10 years (2007-2017) on inhibition based enzymatic electrochemical biosensors for the analysis of different drugs. New assays based on novel bio-devices will be debated. Moreover, the exploration of the recent graphical approach in diagnosis of reversible and irreversible inhibition mechanism will be discussed. The accurate and the fast diagnosis of inhibition type will help researchers in further drug design improvements and the identification of new molecules that will serve as new enzyme targets.

Biosensors and Bioelectronics, Feb 1, 2006

Analytical technology based on sensors is an extremely broad field which impacts on many major in... more Analytical technology based on sensors is an extremely broad field which impacts on many major industrial sectors such as the pharmaceutical, healthcare, food, and agriculture industries as well as environmental monitoring. This review will highlight the research carried out during the last 5 years on biosensors that are based on enzyme inhibition for determination of pollutants and toxic compounds in a wide range of samples. Here the different enzymes implicated in the inhibition, different transducers forming the sensing devices, and the different contaminants analyzed are considered. The general application of the various biosensors developed, with emphasis on food and environmental applications, is reviewed as well as the general approaches that have been used for enzyme immobilization, the enzyme catalysis, and the inhibition mechanism.

Evidence-based Complementary and Alternative Medicine, May 5, 2023

In order to highlight the activities of bioactive compounds present in the stem of sweet cherries... more In order to highlight the activities of bioactive compounds present in the stem of sweet cherries, four diferent cultivars (Van, Burlat, Napoleon, and Coeur pigeon) were collected in Sefrou city in Morocco and were studied. Several assays were performed for this purpose, such as the quantifcation of phenolic compounds (TPC, TFC, and CTC) and the evaluation of the antioxidant activity using DPPH, ABTS, and FRAP assays. Te phenolic profle of each extract was characterized by UHPLC-DAD/MS analysis. Te antidiabetic (α-amylase inhibition) and antigout (xanthine oxidase inhibition) activities were also investigated. Te results showed high levels of phenolic compounds, with the values of 340 ± 12.06, 244 ± 10.20, 232 ± 5.07, and 19 ± 3.10 mg gallic acid equivalent/g extract for the cultivars Napoleon, Coeur de pigeon, Van, and Burlat, respectively. According to the same order, the favonoids showed amounts of 34.31 ± 2.08, 23.75 ± 1.02, 24.37 ± 1.20, and 23.31 ± 0.90 mg (rutin equivalent) RE/g extract. Tese values were correlated with the results of the antioxidant assays, where the Napoleon cultivar proved to be the most potent using the DPPH (IC 50 = 2.51 µg/mL) and ABTS (IC 50 = 55.38 µg/mL) assays. Te phenolic profle of each extract resulted in the identifcation of twenty-two compounds belonging to fve distinct groups. Te major phenolic compounds identifed were sakuranetin and dihydrowgonin with their glucosides. Antidiabetic activity assays showed that only stem extracts from Burlat and Napoleon cultivars were able to inhibit the α-amylase enzyme with values of 85.57 ± 1.09% and 68.01 ± 3.52%, respectively. All stem extracts proved their ability to inhibit the xanthine oxidase enzyme which is directly linked to the gout disease, with a high value for Van cultivar (40.63 ± 2.37%). Tese new fndings could provide new opportunities for the valorization of cherry stems for the pharmaceutical application of their active phytochemicals.

Food Chemistry, Jun 1, 2006

A commercial kit (Gly-Pro), usually used for clinical diagnosis relative to diabetes, was employe... more A commercial kit (Gly-Pro), usually used for clinical diagnosis relative to diabetes, was employed to estimate the effect of heat treatment applied to food and also protein-sugar model systems. The assay employs two enzymatic reagents that react with glycated proteins that result from the Maillard reaction; the hydrogen peroxide produced is then consumed in a colorimetric reaction. Food samples and model systems were heated and incubated at different temperatures and holding times. The enzymatic method was demonstrated to be useful for detecting early products of the Maillard reaction. However, the Gly-Pro kit seems to be specific for glucose binding proteins.

Journal of Herbs, Spices & Medicinal Plants, May 3, 2022

Journal of HerbMed Pharmacology, Oct 20, 2020

Extracts of Pinus halepensis exhibited remarkable antioxidant and antidiabetic effects, which may... more Extracts of Pinus halepensis exhibited remarkable antioxidant and antidiabetic effects, which may have significant implications for the future development of antidiabetic drugs from P. halepensis.

Enzyme and microbial technology, 2017

Highlights  Novel sensing device based on the achievement of high-throughput by simultaneous pre... more Highlights  Novel sensing device based on the achievement of high-throughput by simultaneous preparation of up to 96 samples using multiwell plates for sulfonamides screening.  Novel electrochemical Carbonic Anhydrase (CA) inhibition biosensor for sulfanilamide determination.  CA inhibition mechanism was noncompetitive for sulfanilamide.  Interference study demonstrated very good selectivity towards sulfanilamide.

Les technologies de laboratoire, 2006

Les aflatoxines sont des métabolites produits par des moisissures du genre Aspergillus et plus pa... more Les aflatoxines sont des métabolites produits par des moisissures du genre Aspergillus et plus particulièrement A. flavus et A. parsiticus se développant sur différents produits alimentaires. Ainsi, on les trouve dans les céréales, le maïs, le riz et aussi dans les graines de coton, les épices et le lait. Ces mycotoxines sont connues pour leur grande toxicité et leurs effets mutagéniques, tératogéniques et carcinogéniques. C'est ainsi que de nombreux pays ont instauré une législation stricte quand aux quantités maximales admissibles des aflatoxines dans les aliments. La protection contre d'éventuelles aflatoxicoses reste évidente. Seul le contrôle continu des aliments assure leur innocuité. Des techniques performantes et sensibles sont largement utilisées pour ces fins sécuritaires.

The Journal of Microbiology, Biotechnology and Food Sciences, Jun 2, 2022

This work aims to determine the antioxidant, antibacterial properties and chemical profile of the... more This work aims to determine the antioxidant, antibacterial properties and chemical profile of the essential oil (EO) of Lavandula multifida (LM) at the flowering stage collected in northwestern Morocco. So far, information on essential oils of L. multifida remains limited. The extraction yield of the essential oil was 0.46%. The composition was determined by GC-MS-FID. Twenty compounds were identified and the major phytochemicals were carvacrol, ß-bisabolene, and careophyllene oxide (44.3%, 31.9%, and 5.8% respectively). In addition, information on the essential oil of L. multifida collected in the Rabat region is reported for the first time in this study. DPPH and FRAP tests were used to evaluate its antioxidant activity. Antibacterial activities were also studied. Indeed, the essential oil of L. multifida exhibited inhibition effects on the growth of various microorganisms, including S. aureus where the MIC and MBC were equal to 0.5 and 2μg/ml, respectively. Therefore, the use of Lavandula multifida essential oil shows great promise in various fields. ARTICLE INFO

Analytical Letters, Aug 1, 2005

A novel method of extraction has been developed to avoid the presence of heavy metals during the ... more A novel method of extraction has been developed to avoid the presence of heavy metals during the measurement of pesticides based on acetylcholinesterase (AchE) inhibition. Heavy metals have been in fact demonstrated in this article to interfere when the assay is performed by using the classic spectrophotometric Ellman's method. We present the results obtained with an assay system using two different phases, one organic and the other aqueous, in which the pesticide and the enzyme are, respectively, solubilized. In a first step, the concentration of the substrate acetylthiocholine (1 mM), of the enzyme (7 mU mL 21), and the reaction time (20 min) for measurement of enzyme activity were optimized in aqueous solution. Next, the effect of an organic phase on the enzyme activity was studied by the addition of various solvents with the activity being evaluated after 10 min of mixing. It was found that by using hexane, the enzyme retained almost 100% of its

Analytical Letters, Dec 27, 2004

The electrocatalytic activity of copper-modified gold electrodes has been investigated for the si... more The electrocatalytic activity of copper-modified gold electrodes has been investigated for the simultaneous detection of glucose and starch using a-amyloglucosidase in solution. The amperometric response of glucose at the modified gold electrode was monitored for different copper loadings (0.04, 0.1, 0.2, and 0.3 mg cm 22), that of 0.2 mg cm 22 deposited on the electrode surface being chosen for further investigation. The surface characteristics were confirmed by the electrochemical impedance spectra. The oxidation of glucose and starch was studied by linear sweep voltammetry (LSV) in order to determine the best applied potential for measuring

Plants, Dec 2, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Biocatalysis and Agricultural Biotechnology

Progress In Microbes & Molecular Biology

Exopolysaccharides, known as bacterial EPS, are complex sugar polymers that bacteria secrete into... more Exopolysaccharides, known as bacterial EPS, are complex sugar polymers that bacteria secrete into their environment. EPSs play a crucial role in bacterial survival and proliferation by protecting cells from environmental threats. They also contribute to proper adhesion to numerous surfaces through biofilm production. Bacterial EPS display a wide range of biological activities conferred by their outstanding physical and chemical properties, which make them great candidates for medical and industrial applications. The main biological activities recorded up-to-day include antioxidant, anticancer, antiviral, anti-inflammatory, anticancer, antibacterial, immune-modulatory and chelating properties. They also can be used as thickening agents in the industry or as additives to improve soil quality in agriculture. The current review offers a thorough overview of bacterial EPS, their biosynthesis processes and regulation, and biotechnological strategies to increase their production. The revie...

Biosensors & bioelectronics, Jan 5, 2015

Graphene as a star among two-dimensional nanomaterials has attracted tremendous research interest... more Graphene as a star among two-dimensional nanomaterials has attracted tremendous research interest in the field of electrochemistry due to their intrinsic properties, including the electronic, optical, and mechanical properties associated with their planar structure. The marriage of graphene and electrochemical biosensors has created many ingenious biosensing strategies for applications in the areas of clinical diagnosis and food safety. This review provides a comprehensive overview of the recent advances in the development of graphene based electrochemical biosensors. Special attention is paid to graphene-based enzyme biosensors, immunosensors, and DNA biosensors. Future perspectives on high-performance graphene-based electrochemical biosensors are also discussed.

Evidence-Based Complementary and Alternative Medicine

Molecules

Leaves, husk, kernels, and bark methanolic extracts of Juglans regia L. were tested for their in ... more Leaves, husk, kernels, and bark methanolic extracts of Juglans regia L. were tested for their in vitro antidiabetic, anti-inflammatory, and antioxidant activities. For these purposes, α-amylase and α-glucosidase were used as the main enzymes to evaluate antidiabetic activities. Moreover, lipoxidase and tyrosinase activities were tested to estimate anti-inflammatory properties. Antioxidant properties of Juglans regia L., extracts were determined using three different assays. Leaves extract has an important radical scavenging activity and a-amylase inhibition. Similarly, husk extracts showed high total phenolic content (306.36 ± 4.74 mg gallic acid equivalent/g dry extract) with an important α-amylase inhibition (IC50 = 75.42 ± 0.99 µg/mL). Kernels exhibit significant tyrosinase (IC50 = 51.38 ± 0.81 µg/mL) correlated with antioxidant activities (p < 0.05). Husk and bark extracts also showed strong anti-lipoxidase activities with IC50 equal to 29.48 ± 0.28 and 28.58 ± 0.35 µg/mL, re...