ORCID Profile
0000-0002-9787-3996
Current Organisations
Swinburne University of Technology
,
Universidad del Desarrollo
,
University of Nottingham
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Publisher: Springer Science and Business Media LLC
Date: 24-04-2023
Publisher: Springer Science and Business Media LLC
Date: 29-09-2022
DOI: 10.1007/S00204-022-03382-3
Abstract: With more than 80 cytochrome P450 (CYP) encoding genes found in the nematode Caenorhabditis elegans (C. elegans), the cyp35 genes are one of the important genes involved in many biological processes such as fatty acid synthesis and storage, xenobiotic stress response, dauer and eggshell formation, and xenobiotic metabolism. The C. elegans CYP35 subfamily consisted of A, B, C, and D, which have the closest homolog to human CYP2 family. C. elegans homologs could answer part of the hunt for human disease genes. This review aims to provide an overview of CYP35 in C. elegans and their human homologs, to explore the roles of CYP35 in various C. elegans biological processes, and how the genes of cyp35 upregulation or downregulation are influenced by biological processes, upon exposure to xenobiotics or changes in diet and environment. The C. elegans CYP35 gene expression could be upregulated by heavy metals, pesticides, anti-parasitic and anti-chemotherapeutic agents, polycyclic aromatic hydrocarbons (PAHs), nanoparticles, drugs, and organic chemical compounds. Among the cyp35 genes, cyp-35A2 is involved in most of the C. elegans biological processes regulation. Further venture of cyp35 genes, the closest homolog of CYP2 which is the largest family of human CYPs, may have the power to locate cyps gene targets, discovery of novel therapeutic strategies, and possibly a successful medical regime to combat obesity, cancers, and cyps gene-related diseases.
Publisher: Elsevier BV
Date: 2022
Publisher: Walter de Gruyter GmbH
Date: 17-08-2021
DOI: 10.1515/DMPT-2021-1000196
Abstract: Khat, a natural hetamine-like psychostimulant plant, are widely consumed globally. Concurrent intake of khat and xenobiotics may lead to herb-drug interactions and adverse drug reactions (ADRs). This study is a continuation of our previous study, targeted to evaluate the in vitro inhibitory effects of khat ethanol extract (KEE) on human cytochrome (CYP) 1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, and CYP3A5, major human drug metabolizing enzymes. In vitro fluorescence enzyme assays were employed to assess CYPs inhibition with the presence and absence of various KEE concentrations. KEE reversibly inhibited CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 but not CYP1A2 with IC 50 values of 25.5, 99, 4.5, 21, 27, 17, and 10 μg/mL respectively. No irreversible inhibition of KEE on all the eight CYPs were identified. The K i values of CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2 and CYP3A5 were 20.9, 85, 4.8, 18.3, 59.3, 3, and 21.7 μg/mL, respectively. KEE inhibited CYP2B6 via competitive or mixed inhibition CYP2E1 via un-competitive or mixed inhibition while CYP2A6, CYP2C8, CYP2C19, CYP2J2 and CYP3A5 via non-competitive or mixed inhibition. Caution should be taken by khat users who are on medications metabolized by CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2E1, CYP2J2, and CYP3A5.
Publisher: Springer International Publishing
Date: 2022
Publisher: SAGE Publications
Date: 13-02-2020
Abstract: Cytochrome P450 4B1 (CYP4B1) plays crucial roles in biotransforming of xenobiotics. Its predominant extrahepatic expression has been associated with certain tissue-specific toxicities. However, the expressions of CYP4B1 in various cancers and hence their potential roles in cancer development were inclusive. In this work, existing knowledge on expression and regulation of CYP4B1 gene and protein, catalysis of CYP4B1, association of CYP4B1 with cancers, contradicting findings about human CYP4B1 activities as well as the employing CYP4B1 in suicide gene approach for cancer treatment were reviewed. To date, it appears that there is a wide spectrum of tissue distribution of CYP4B1 with lungs as the predominant sites. Several nuclear receptors are possibly responsible for regulating its gene expression. The involvement of CYP4B1 in cancer was considered via activation of procarcinogens and neovascularization. However, human CYP4B1 was found to be inactive due to a substitution of proline with serine at position 427. Suicide gene approach combining reengineered CYP4B1 and prodrug 4-ipomeanol (4-IPO) has shown a promising potential for targeted cancer therapy. Further studies should focus on the verification of human CYP4B1 catalytic activities. More compounds with similar structure as 4-IPO should be tested to identify more alternative agents for the suicide gene approach in cancer treatment.
Publisher: Springer Science and Business Media LLC
Date: 17-07-2023
Publisher: Springer Science and Business Media LLC
Date: 10-10-2018
DOI: 10.1007/S13318-018-0518-2
Abstract: A significant number of people worldwide consume khat on daily basis. Long term of khat chewing has shown negative impact on several organ systems. It is likely that these people are co-administered khat preparations and conventional medication, which may lead to khat-drug interactions. This study aimed to reveal the inhibitory potencies of khat ethanol extract (KEE) and its major active ingredient (cathinone) on human cytochrome P450 (CYP) 2C9, CYP2D6, and CYP3A4 enzymes activities, which are collectively responsible for metabolizing 70-80% clinically used drugs. In vitro fluorescence-based enzyme assays were developed and the CYP enzyme activities were quantified in the presence and absence of KEE and cathinone employing Vivid KEE inhibited human CYP2C9, CYP2D6, and CYP3A4 enzyme activities with IC Khat-drug interactions are possible due to administration of clinical drugs metabolized by CYP2C9/CYP2D6/CYP3A4 together with khat chewing. Further in vivo studies are required to confirm our findings and identify the causative constituents of these inhibitory effects.
Publisher: Elsevier BV
Date: 11-2022
Publisher: SAGE Publications
Date: 04-06-2022
DOI: 10.1177/10915818221103790
Abstract: Cathine is the stable form of cathinone, the major active compound found in khat ( Catha edulis Forsk) plant. Khat was found to inhibit major phase I drug metabolizing cytochrome P450 (CYP) enzyme activities in vitro and in vivo. With the upsurge of khat consumption and the potential use of cathine to combat obesity, efforts should be channelled into understanding potential cathine-drug interactions, which have been rather limited. The present study aimed to assess CYPs activity and inhibition by cathine in a high-throughput in vitro fluorescence-based enzyme assay and molecular docking analysis to identify how cathine interacts within various CYPs’ active sites. The half maximal inhibitory concentration (IC 50 ) values of cathine determined for CYP2A6 and CYP3A4 were 80 and 90 μM, while CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, CYP2J2 and CYP3A5 showed no significant inhibition. Furthermore, in K i analysis, the Lineweaver-Burk plots depicted non-competitive mixed inhibition of cathine on both CYP2A6 and CYP3A4 with K i value of 63 and 100 μM, respectively. Cathine showed negligible time-dependent inhibition on CYPs. Further, molecular docking studies showed that cathine was bound to CYP2A6 via hydrophobic, hydrogen and π-stacking interactions and formed hydrophobic and hydrogen bonds with active site residues in CYP3A4. Both molecular docking prediction and in vitro outcome are in agreement, granting more detailed insights for predicting CYPs metabolism besides the possible cathine-drug interactions. Cathine-drug interactions may occur with concomitant consumption of khat or cathine-containing products with medications metabolized by CYP2A6 and CYP3A4.
Publisher: Bentham Science Publishers Ltd.
Date: 12-2023
DOI: 10.2174/2210315513666230307115348
Abstract: Mangiferin has been identified as one of the major active constituents of Aquilaria plants. It was reported to have several promising chemotherapeutic potentials. Our preliminary data suggested that Aquilaria plant water extracts inhibited several cytochrome P450 (CYP) isoenzymes in vitro. This study aimed to investigate the modulatory effects of mangiferin on six major drug metabolizing CYP enzymes including CYP2A6, CYP2B6, CYP2C9, CYP2D6, CYP3A4, and CYP3A5. The enzyme activities were measured using fluorescence-based assays and enzyme kinetic such as IC50 parameters and Ki values were calculated to evaluate inhibitory potencies and mechanisms. Moreover, for potent inhibitions, molecular docking studies were carried out to explore potential interactions of residues between mangiferin and CYP enzymes. Our findings suggested that mangiferin could inhibit CYP2D6, CYP3A4, and CYP3A5 in vitro with IC50 values of 9.2, 8.7, and 4.3 μM, and Ki values of 3.8, 10.8, and 9.6 μM, in a non-competitive inhibition pattern. Molecular docking studies using AutoDock 4.2 identified potential residues contained in mangiferin that interacted with CYP2D6, CYP3A4, and CYP3A5, resulting in the observed inhibitory effects. Mangiferin should be used carefully, in particular, with conventional drugs metabolized mainly by CYP2D6, CYP3A4, and CYP3A5. Further in vivo studies are recommended to evaluate the clinical relevance of these inhibitions.
Publisher: Springer International Publishing
Date: 2022
Publisher: Informa UK Limited
Date: 28-12-2020
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Sharoen Yu Ming Lim.