Displaying publications 1 - 20 of 88 in total

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  1. Abdallah HH, Mavri J, Repič M, Lee VS, Wahab HA
    Int J Mol Sci, 2012;13(2):1269-83.
    PMID: 22408390 DOI: 10.3390/ijms13021269
    Genistein, daidzein, glycitein and quercetin are flavonoids present in soybean and other vegetables in high amounts. These flavonoids can be metabolically converted to more active forms, which may react with guanine in the DNA to form complexes and can lead to DNA depurination. We assumed two ultimate carcinogen forms of each of these flavonoids, diol epoxide form and diketone form. Density functional theory (DFT) and Hartree-Fock (HF) methods were used to study the reaction thermodynamics between active forms of flavonoids and DNA guanine. Solvent reaction field method of Tomasi and co-workers and the Langevin dipoles method of Florian and Warshel were used to calculate the hydration free energies. Activation free energy for each reaction was estimated using the linear free energy relation. Our calculations show that diol epoxide forms of flavonoids are more reactive than the corresponding diketone forms and are hence more likely flavonoid ultimate carcinogens. Genistein, daidzein and glycitein show comparable reactivity while quercetin is less reactive toward DNA.
  2. Abdulbaqi IM, Assi RA, Yaghmur A, Darwis Y, Mohtar N, Parumasivam T, et al.
    Pharmaceuticals (Basel), 2021 Jul 27;14(8).
    PMID: 34451824 DOI: 10.3390/ph14080725
    Lung cancer (LC) is the leading cause of cancer-related deaths, responsible for approximately 18.4% of all cancer mortalities in both sexes combined. The use of systemic therapeutics remains one of the primary treatments for LC. However, the therapeutic efficacy of these agents is limited due to their associated severe adverse effects, systemic toxicity and poor selectivity. In contrast, pulmonary delivery of anticancer drugs can provide many advantages over conventional routes. The inhalation route allows the direct delivery of chemotherapeutic agents to the target LC cells with high local concertation that may enhance the antitumor activity and lead to lower dosing and fewer systemic toxicities. Nevertheless, this route faces by many physiological barriers and technological challenges that may significantly affect the lung deposition, retention, and efficacy of anticancer drugs. The use of lipid-based nanocarriers could potentially overcome these problems owing to their unique characteristics, such as the ability to entrap drugs with various physicochemical properties, and their enhanced permeability and retention (EPR) effect for passive targeting. Besides, they can be functionalized with different targeting moieties for active targeting. This article highlights the physiological, physicochemical, and technological considerations for efficient inhalable anticancer delivery using lipid-based nanocarriers and their cutting-edge role in LC treatment.
  3. Abduraman MA, Hariono M, Yusof R, Rahman NA, Wahab HA, Tan ML
    Heliyon, 2018 Dec;4(12):e01023.
    PMID: 30560214 DOI: 10.1016/j.heliyon.2018.e01023
    Background: Dengue infection is an endemic infectious disease and it can lead to dengue fever, dengue hemorrhagic fever, and/or dengue shock syndromes. Dengue NS2B/NS3 protease complex is essential for viral replication and is a primary target for anti-dengue drug development. In this study, a NS2B/NS3 protease inhibition assay was developed using AlphaScreen® beads and was used to screen compounds for their protease inhibition activities.

    Methods: The assay system utilized a known NS2B/NS3 peptide substrate, a recombinant of NS2B/NS3 protease with proprietary StrepTactin® donor and nickel chelate acceptor beads in 384-well format.

    Results: The optimized assay to screen for NS2B/NS3 protease inhibitors was demonstrated to be potentially useful with reasonable z' factor, coefficient variance and signal to background ratio. However, screening of synthesized thioguanine derivatives using the optimized AlphaScreen® assay revealed weak NS2B/NS3 inhibition activities.

    Conclusion: The AlphaScreen® assay to screen for NS2B/NS3 protease inhibitors is potentially applicable for high throughput screening.

  4. Abou Assi R, Abdulbaqi IM, Tan SM, Wahab HA, Darwis Y, Chan SY
    Drug Dev Ind Pharm, 2023 Sep 18.
    PMID: 37722711 DOI: 10.1080/03639045.2023.2256404
    OBJECTIVE: Breast cancer affects women globally, regardless of age or location. On the other hand, Tamoxifen (TXN), a class II biopharmaceutical drug is acting as a prophylactic/treating agent for women at risk of and/or with hormone receptor-positive breast cancer. However, its oral administration has life-threatening side effects, which have led researchers to investigate alternative delivery methods. One such method is transdermal drug delivery utilizing bile salts as penetration enhancers, aka Bilosomes.

    METHODS: Bilosomes formulations were optimized statistically for the outcome of vesicle shape, size, and entrapment efficiency using two types of bile, i.e. sodium taurocholate and sodium cholate. These bilosomes were then loaded into HPMC base gel and further characterized for their morphology, drug content, pH, viscosity, spreadability and eventually ex-vivo skin penetration and deposition studies.

    RESULTS: Findings showed that sodium cholate has superiority as a penetration enhancer over sodium taurocholate in terms of morphological characterizes, zeta potential, and cumulative amounts of tamoxifen permeated per unit area (15.13 ± 0.71 μg/cm2 and 6.51 ± 0.6 μg/cm2 respectively). In fact, bilosomes designed with sodium cholate provided around 9 folds of skin deposition compared to TXN non-bilosomal gel.

    CONCLUSION: Bilosomes gels could be a promising option for locally delivering tamoxifen to the breast through the skin, offering an encouraging transdermal solution.

  5. Ahmad R, Khairul Nizam Mazlan M, Firdaus Abdul Aziz A, Mohd Gazzali A, Amir Rawa MS, Wahab HA
    Saudi Pharm J, 2023 Jun;31(6):874-888.
    PMID: 37234341 DOI: 10.1016/j.jsps.2023.04.006
    Phaleria macrocarpa (Scheff.) Boerl. is geographically distributed around Papua Island, Indonesia. Traditionally, P. macrocarpa is exercised to reduce pain, stomachache, diarrhea, tumor problems, blood glucose, cholesterol, and blood pressure. A growing interest in the medicinal values of P. macrocarpa especially in Asia reflects the usage of diverse extraction techniques, particularly modern approaches. In this review article, the extraction methods and solvents relevant to P. macrocarpa were discussed, with the extent of its pharmacological activities. Recent bibliographic databases such as Google Scholar, PubMed, and Elsevier between 2010 and 2022 were assessed. Based on the findings, the pharmacological studies of P. macrocarpa are still pertinent to its traditional uses but primarily emphasise anti-proliferative activity especially colon and breast cancer cells with low toxicity and fruit as the most studied plant part. The utilization of modern separation techniques has predominantly been aimed at extracting mangiferin and phenolic-rich compounds and evaluating their antioxidant capacity. However, the isolation of bioactive compounds remains a challenge, leading to the extensive utilization of the extracts in in vivo studies. This review endeavors to highlight modern extraction methods that could potentially be used as a point of reference in the future for exploring novel bioactive compounds and drug discovery on a multi-scale extraction level.
  6. Al-Najjar BO, Wahab HA, Tengku Muhammad TS, Shu-Chien AC, Ahmad Noruddin NA, Taha MO
    Eur J Med Chem, 2011 Jun;46(6):2513-29.
    PMID: 21482446 DOI: 10.1016/j.ejmech.2011.03.040
    Peroxisome Proliferator-Activated Receptor γ (PPARγ) activators have drawn great recent attention in the clinical management of type 2 diabetes mellitus, prompting several attempts to discover and optimize new PPARγ activators. With this in mind, we explored the pharmacophoric space of PPARγ using seven diverse sets of activators. Subsequently, genetic algorithm and multiple linear regression analysis were employed to select an optimal combination of pharmacophoric models and 2D physicochemical descriptors capable of accessing self-consistent and predictive quantitative structure-activity relationship (QSAR) (r2(71)=0.80, F=270.3, r2LOO=0.73, r2PRESS against 17 external test inhibitors=0.67). Three orthogonal pharmacophores emerged in the QSAR equation and were validated by receiver operating characteristic (ROC) curves analysis. The models were then used to screen the national cancer institute (NCI) list of compounds. The highest-ranking hits were tested in vitro. The most potent hits illustrated EC50 values of 15 and 224 nM.
  7. Al-Thiabat MG, Saqallah FG, Gazzali AM, Mohtar N, Yap BK, Choong YS, et al.
    Molecules, 2021 Feb 18;26(4).
    PMID: 33670773 DOI: 10.3390/molecules26041079
    Folate receptor alpha (FRα) is known as a biological marker for many cancers due to its overexpression in cancerous epithelial tissue. The folic acid (FA) binding affinity to the FRα active site provides a basis for designing more specific targets for FRα. Heterocyclic rings have been shown to interact with many receptors and are important to the metabolism and biological processes within the body. Nineteen FA analogs with substitution with various heterocyclic rings were designed to have higher affinity toward FRα. Molecular docking was used to study the binding affinity of designed analogs compared to FA, methotrexate (MTX), and pemetrexed (PTX). Out of 19 FA analogs, analogs with a tetrazole ring (FOL03) and benzothiophene ring (FOL08) showed the most negative binding energy and were able to interact with ASP81 and SER174 through hydrogen bonds and hydrophobic interactions with amino acids of the active site. Hence, 100 ns molecular dynamics (MD) simulations were carried out for FOL03, FOL08 compared to FA, MTX, and PTX. The root mean square deviation (RMSD) and root mean square fluctuation (RMSF) of FOL03 and FOL08 showed an apparent convergence similar to that of FA, and both of them entered the binding pocket (active site) from the pteridine part, while the glutamic part was stuck at the FRα pocket entrance during the MD simulations. Molecular mechanics Poisson-Boltzmann surface accessible (MM-PBSA) and H-bond analysis revealed that FOL03 and FOL08 created more negative free binding and electrostatic energy compared to FA and PTX, and both formed stronger H-bond interactions with ASP81 than FA with excellent H-bond profiles that led them to become bound tightly in the pocket. In addition, pocket volume calculations showed that the volumes of active site for FOL03 and FOL08 inside the FRα pocket were smaller than the FA-FRα system, indicating strong interactions between the protein active site residues with these new FA analogs compared to FA during the MD simulations.
  8. Al-Thiabat MG, Gazzali AM, Mohtar N, Murugaiyah V, Kamarulzaman EE, Yap BK, et al.
    Molecules, 2021 Aug 31;26(17).
    PMID: 34500740 DOI: 10.3390/molecules26175304
    Drug targeting is a progressive area of research with folate receptor alpha (FRα) receiving significant attention as a biological marker in cancer drug delivery. The binding affinity of folic acid (FA) to the FRα active site provides a basis for recognition of FRα. In this study, FA was conjugated to beta-cyclodextrin (βCD) and subjected to in silico analysis (molecular docking and molecular dynamics (MD) simulation (100 ns)) to investigate the affinity and stability for the conjugated system compared to unconjugated and apo systems (ligand free). Docking studies revealed that the conjugated FA bound into the active site of FRα with a docking score (free binding energy < -15 kcal/mol), with a similar binding pose to that of unconjugated FA. Subsequent analyses from molecular dynamics (MD) simulations, root mean square deviation (RMSD), root mean square fluctuation (RMSF), and radius of gyration (Rg) demonstrated that FA and FA-βCDs created more dynamically stable systems with FRα than the apo-FRα system. All systems reached equilibrium with stable RMSD values ranging from 1.9-2.4 Å and the average residual fluctuation values of the FRα backbone atoms for all residues (except for terminal residues ARG8, THR9, THR214, and LEU215) were less than 2.1 Å with a consistent Rg value of around 16.8 Å throughout the MD simulation time (0-100 ns). The conjugation with βCD improved the stability and decreased the mobility of all the residues (except residues 149-151) compared to FA-FRα and apo-FRα systems. Further analysis of H-bonds, binding free energy (MM-PBSA), and per residue decomposition energy revealed that besides APS81, residues HIS20, TRP102, HIS135, TRP138, TRP140, and TRP171 were shown to have more favourable energy contributions in the holo systems than in the apo-FRα system, and these residues might have a direct role in increasing the stability of holo systems.
  9. Alhawarri MB, Dianita R, Razak KNA, Mohamad S, Nogawa T, Wahab HA
    Molecules, 2021 Apr 29;26(9).
    PMID: 33946788 DOI: 10.3390/molecules26092594
    Despite being widely used traditionally as a general tonic, especially in South East Asia, scientific research on Cassia timoriensis, remains scarce. In this study, the aim was to evaluate the in vitro activities for acetylcholinesterase (AChE) inhibitory potential, radical scavenging ability, and the anti-inflammatory properties of different extracts of C. timoriensis flowers using Ellman's assay, a DPPH assay, and an albumin denaturation assay, respectively. With the exception of the acetylcholinesterase activity, to the best of our knowledge, these activities were reported for the first time for C. timoriensis flowers. The phytochemical analysis confirmed the existence of tannins, flavonoids, saponins, terpenoids, and steroids in the C. timoriensis flower extracts. The ethyl acetate extract possessed the highest phenolic and flavonoid contents (527.43 ± 5.83 mg GAE/g DW and 851.83 ± 10.08 mg QE/g DW, respectively) as compared to the other extracts. In addition, the ethyl acetate and methanol extracts exhibited the highest antioxidant (IC50 20.12 ± 0.12 and 34.48 ± 0.07 µg/mL, respectively), anti-inflammatory (92.50 ± 1.38 and 92.22 ± 1.09, respectively), and anti-AChE (IC50 6.91 ± 0.38 and 6.40 ± 0.27 µg/mL, respectively) activities. These results suggest that ethyl acetate and methanol extracts may contain bioactive compounds that can control neurodegenerative disorders, including Alzheimer's disease, through high antioxidant, anti-inflammatory, and anti-AChE activities.
  10. Amir Rawa MS, Hassan Z, Murugaiyah V, Nogawa T, Wahab HA
    J Ethnopharmacol, 2019 Dec 05;245:112160.
    PMID: 31419500 DOI: 10.1016/j.jep.2019.112160
    ETHNOPHARMACOLOGICAL RELEVANCE: Enhancement of cholinergic functions in the brain via acetylcholinesterase inhibition is one of the main therapeutic strategies to improve symptoms associated with Alzheimer's or related cognitive deficits. There is a pathophysiological correlation between Alzheimer's and Diabetes Mellitus, as well as inflammation and oxidative stress that may cause cognitive decline.

    AIM OF THE STUDY: The present study was intended to evaluate anti-cholinesterase potential of 177 Malaysian plant extracts from 148 species known to have related ethnomedicinal uses such as anti-inflammatory, anti-oxidant, anti-diabetic, epilepsy, headache, memory enhancement and anti-aging.

    MATERIALS AND METHODS: Anti-cholinesterase screening against both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes was performed on the basis of in-vitro colorimetric 96-well microplate-based assay method. Potent active plant extracts were subjected to liquid-liquid extraction and acid-base fractionation for further analysis.

    RESULTS: Fifty-seven plant extracts exhibited potent anti-cholinesterase activities (50-100% inhibition) at 200 μg/ml. Majority of the active plants originated from Fabaceae family. Coccoloba uvifera (L.) L. stem extract manifested the lowest IC50 of 3.78 μg/ml for AChE and 5.94 μg/ml for BChE. A few native species including Tetracera indica (Christm. & Panz.) Merr., Cyrtostachys renda Blume and Ixora javanica (Blume) DC. showed cholinesterase inhibition despite limited local medical applications. Further anti-AChE evaluation (50 μg/ml) of 18 potent plant extracts harbored active polar components in butanol and water fractions, except Senna pendula (Willd.) H.S.Irwin & Barneby (leaves and stems), Acacia auriculiformis Benth. (leaves), Artocarpus altilis (Parkinson ex F.A.Zorn) Fosberg (leaves), and Macaranga tanarius (L.) Mull.Arg. (leaves) that showed inhibitory activity in less polar fractions. The acidic extraction of these four plant species improved their inhibition level against AChE.

    CONCLUSION: This study rendered a preliminary overview of anti-cholinesterase activity from diverse Malaysian botanical families in which provided the medical relevance toward these native plant species, especially ones with limited ethnobotanical record or practice.

  11. Azman NAN, Alhawarri MB, Rawa MSA, Dianita R, Gazzali AM, Nogawa T, et al.
    Molecules, 2020 Oct 04;25(19).
    PMID: 33020403 DOI: 10.3390/molecules25194545
    Seventeen methanol extracts from different plant parts of five different Cassia species, including C. timorensis, C. grandis, C. fistula, C. spectabilis, and C. alata were screened against acetylcholinesterase (AChE). C. timorensis extracts were found to exhibit the highest inhibition towards AChE whereby the leaf, stem, and flower methanol extracts showed 94-97% inhibition. As far as we are aware, C. timorensis is one of the least explored Cassia spp. for bioactivity. Further fractionation led to the identification of six compounds, isolated for the first time from C. timorensis: 3-methoxyquercetin (1), benzenepropanoic acid (2), 9,12,15-octadecatrienoic acid (3), β-sitosterol (4), stigmasterol (5), and 1-octadecanol (6). Compound 1 showed moderate inhibition towards AChE (IC50: 83.71 μM), while the other compounds exhibited poor to slightly moderate AChE inhibitory activity. Molecular docking revealed that the methoxy substitution of 1 formed a hydrogen bond with TYR121 at the peripheral anionic site (PAS) and the hydroxyl group at C5 formed a covalent hydrogen bond with ASP72. Additionally, the OH group at the C3' position formed an interaction with the protein at the acyl pocket (PHE288). This possibly explains the activity of 1 in blocking the entry of acetylcholine (ACh, the neurotransmitter), thus impeding the hydrolysis of ACh.
  12. Choi SB, Normi YM, Wahab HA
    BMC Bioinformatics, 2011;12 Suppl 13:S11.
    PMID: 22372825 DOI: 10.1186/1471-2105-12-S13-S11
    Previously, the hypothetical protein, KPN00728 from Klebsiella pneumoniae MGH78578 was the Succinate dehydrogenase (SDH) chain C subunit via structural prediction and molecular docking simulation studies. However, due to limitation in docking simulation, an in-depth understanding of how SDH interaction occurs across the transmembrane of mitochondria could not be provided.
  13. Choi SB, Normi YM, Wahab HA
    Protein J, 2009 Dec;28(9-10):415-27.
    PMID: 19859792 DOI: 10.1007/s10930-009-9209-9
    Twenty percent of genes that encode for hypothetical proteins from Klebsiella pneumoniae MGH78578 were identified, leading to KPN00728 and KPN00729 after bioinformatics analysis. Both open reading frames showed high sequence homology to Succinate dehydrogenase Chain C (SdhC) and D (SdhD) from Escherichia coli. Recently, KPN00729 was assigned as SdhD. KPN00728 thus remains of particular interest as no annotated genes from the complete genome sequence encode for SdhC. We discovered KPN00728 has a missing region with conserved residues important for ubiquinone (UQ) and heme group binding. Structure and function prediction of KPN00728 coupled with secondary structure analysis and transmembrane topology showed KPN00728 adopts SDH-(subunit C)-like structure. To further probe its functionality, UQ was docked on the built model (consisting KPN00728 and KPN00729) and formation of hydrogen bonds between UQ and Ser27, Arg31 (KPN00728) and Tyr84 (KPN00729) further reinforces and supports that KPN00728 is indeed SDH. This is the first report on the structural and function prediction of KPN00728 of K. pneumoniae MGH78578 as SdhC.
  14. Choi SB, Choong YS, Saito A, Wahab HA, Najimudin N, Watanabe N, et al.
    Mol Inform, 2014 Dec;33(11-12):742-8.
    PMID: 27485420 DOI: 10.1002/minf.201400080
    Present HIV antiviral therapy only targets structural proteins of HIV, but evidence shows that the targeting of accessory proteins will expand our options in combating HIV. HIV-1 Vpr, a multifunctional accessory protein involved in viral infection, replication and pathogenesis, is a potential target. Previously, we have shown that phenyl coumarin compounds can inhibit the growth arrest activity of Vpr in host cells and predicted that the inhibitors' binding site is a hydrophobic pocket on Vpr. To investigate our prediction of the inhibitors' binding site, we docked the coumarin inhibitors into the predicted hydrophobic binding pocket on a built model of Vpr and observed a linear trend between their calculated binding energies and prior experimentally determined potencies. Subsequently, to analyze the inhibitor-protein binding interactions in detail, we built homology models of Vpr mutants and performed docking studies on these models too. The results revealed that structural changes on the binding pocket that were caused by the mutations affected inhibitor binding. Overall, this study showed that the binding energies of the docked molecules are good indicators of the activity of the inhibitors. Thus, the model can be used in virtual screening to identify other Vpr inhibitors and for designing more potent inhibitors.
  15. Cournia Z, Soares TA, Wahab HA, Amaro RE
    J Chem Inf Model, 2021 11 22;61(11):5305-5306.
    PMID: 34668709 DOI: 10.1021/acs.jcim.1c01185
  16. Faisalina AF, Sonvico F, Colombo P, Amirul AA, Wahab HA, Majid MIA
    Nanomaterials (Basel), 2020 Oct 26;10(11).
    PMID: 33114572 DOI: 10.3390/nano10112123
    Polyhydroxyalkanoate (PHA) copolymers show a relatively higher in vivo degradation rate compared to other PHAs, thus, they receive a great deal of attention for a wide range of medical applications. Nanoparticles (NPs) loaded with poorly water-soluble anticancer drug docetaxel (DCX) were produced using poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P(3HB-co-4HB), copolymers biosynthesised from Cupriavidus malaysiensis USMAA1020 isolated from the Malaysian environment. Three copolymers with different molar proportions of 4-hydroxybutirate (4HB) were used: 16% (PHB16), 30% (PHB30) and 70% (PHB70) 4HB-containing P(3HB-co-4HB). Blank and DCX-loaded nanoparticles were then characterized for their size and size distribution, surface charge, encapsulation efficiency and drug release. Preformulation studies showed that an optimised formulation could be achieved through the emulsification/solvent evaporation method using PHB70 with the addition of 1.0% PVA, as stabilizer and 0.03% VitE-TPGS, as surfactant. DCX-loaded PHB70 nanoparticles (DCX-PHB70) gave the desired particle size distribution in terms of average particle size around 150 nm and narrow particle size distribution (polydispersity index (PDI) below 0.100). The encapsulation efficiency result showed that at 30% w/w drug-to-polymer ratio: DCX- PHB16 NPs were able to encapsulate up to 42% of DCX; DCX-PHB30 NPs encapsulated up to 46% of DCX and DCX-PHB70 NPs encapsulated up to 50% of DCX within the nanoparticle system. Approximately 60% of DCX was released from the DCX-PHB70 NPs within 7 days for 5%, 10% and 20% of drug-to-polymer ratio while for the 30% and 40% drug-to-polymer ratios, an almost complete drug release (98%) after 7 days of incubation was observed.
  17. Fatiha Muhammad E, Kumar A, Wahab HA, Zhang KYJ
    Mol Inform, 2021 08;40(8):e2100020.
    PMID: 34060234 DOI: 10.1002/minf.202100020
    Acetylcholinesterase (AChE) inhibitors are the most effective drugs for Alzheimer's disease treatment. However, considering the potential and failure rates of AChE inhibitors, chemical scaffolds targeting cholinesterase specifically are still very limited. Herein, we report a new class of AChE inhibitors identified by employing a virtual screening approach that combines shape similarity with molecular docking calculations. Virtual screening followed by the evaluation of AChE inhibitory activity allowed us to identify 1,2,4-triazolylthioethanones as a novel class of AChE inhibitors. Thirteen compounds with 1,2,4-triazolylthiothanone core and IC50 values in the range of 0.15±0.07 to 3.32±0.92 μM have been reported here. Our findings shed light into a class of AChE inhibitors that could be useful starting point for the development of novel therapeutics to tackle Alzheimer's disease.
  18. Hariono M, Wahab HA, Tan ML, Rosli MM, Razak IA
    PMID: 24764997 DOI: 10.1107/S1600536814001986
    In the title compound, C19H17N5S, the dihedral angles between the purine ring system (r.m.s. deviation = 0.009 Å) and the S-bound and methyl-ene-bound phenyl rings are 74.67 (8) and 71.28 (7)°, respectively. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(8) loops. C-H⋯N inter-actions link the dimers into (100) sheets.
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