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result(s) for
"Al-Dosari, Mohammed S."
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Methotrexate, an anti-inflammatory drug, inhibits Hepatitis E viral replication
by
Khatter, Radhika
,
Sinha, Neha
,
S. Al-Dosari, Mohammed
in
Anti-Inflammatory Agents
,
antiviral
,
Binding sites
2023
Hepatitis E Virus (HEV) is a positively oriented RNA virus having a 7.2 kb genome. HEV consists of three open reading frames (ORF1-3). Of these, ORF1 codes for the enzymes Methyltransferase (Mtase), Papain-like cysteine protease (PCP), RNA helicase, and RNA-dependent RNA polymerase (RdRp). Unavailability of a vaccine or effective drug against HEV and considering the side effects associated with the off-label use of ribavirin (RBV) and pegylated interferons, an alternative approach is required by the modulation of specific enzymes to prevent the infection. HEV helicase is involved in unwinding the double-stranded RNA, RNA processing, transcriptional regulation, and pre-mRNA processing. Therefore, we screened FDA-approved compounds from the ZINC15 database against the modelled 3D structure of HEV helicase and found that methotrexate and compound A (Pubchem ID BTB07890) inhibit the NTPase and dsRNA unwinding activity leading to inhibition of HEV RNA replication. This may be further authenticated by
study.
Journal Article
In silico exploration of deep-sea fungal metabolites as inhibitor of Ebola and Marburg VP35 and VP40
by
Alanzi, Abdullah R.
,
Al-Dosari, Mohammed S.
,
Alqahtani, Moneerah J.
in
Antiviral agents
,
Antiviral Agents - chemistry
,
Antiviral Agents - pharmacology
2024
VP30 and VP40 proteins of Ebola and Marburg viruses have been recognized as potential targets for antiviral drug development due to their essential roles in the viral lifecycle. Targeting these proteins could disrupt key stages of the viral replication process, inhibiting the viruses’ ability to propagate and cause disease. The current study aims to perform molecular docking and virtual screening on deep-sea fungal metabolites targeting Marburg virus VP40 Dimer, matrix protein VP40 from Ebola virus Sudan, Ebola VP35 Interferon Inhibitory Domain, and VP35 from Marburg virus. The top ten compounds for each protein target were chosen using the glide score. All the compounds obtained indicate a positive binding interaction. Furthermore, AdmetSAR was utilized to investigate the pharmacokinetics of the inhibitors chosen. Gliotoxin was used as a ligand with Marburg virus VP40 Dimer, Austinol with matrix protein VP40 from Ebola virus Sudan, Ozazino-cyclo-(2,3-dihydroxyl-trp-tyr) with Ebola VP35 Interferon Inhibitory Domain, and Dehydroaustinol with VP35 from Marburg virus. MD modeling and MMPBSA studies were used to provide a better understanding of binding behaviors. Pre-clinical experiments can assist validate our in-silico studies and assess whether the molecule can be employed as an anti-viral drug.
Journal Article
Plant-derived antiviral drugs as novel hepatitis B virus inhibitors: Cell culture and molecular docking study
by
Tabish Rehman, Md
,
Al-Dosari, Mohammed S.
,
Alqasoumi, Saleh I.
in
Antiviral
,
HBV polymerase
,
Hepatitis B virus
2019
Despite high anti-HBV efficacies, while the nucleoside analogs (e.g., lamivudine) lead to the emergence of drug-resistance, interferons (e.g., IFN-α causes adverse side-effects. Comparatively, various natural or plant products have shown similar or even better efficacy. Hence, new antiviral strategies must focus not only on synthetic molecules but also on potential natural compounds. In this report, we have combined the in vitro cell culture and in silico molecular docking methods to assess the novel anti-HBV activity and delineate the inhibitory mechanism of selected plant-derived pure compounds of different classes. Of the tested (2.5-50 μg/ml) twelve non-cytotoxic compounds, ten (10 μg/ml) were found to maximally inhibit HBsAg production at day 5. Compared to quercetin (73%), baccatin III (71%), psoralen (67%), embelin (65%), menisdaurin (64%) and azadirachtin (62%) that showed high inhibition of HBeAg synthesis, lupeol (52%), rutin (47%), β-sitosterol (43%) and hesperidin (41%) had moderate efficacies against HBV replication. Further assessment of quercetin in combination with the highly active compounds, enhanced its anti-HBV activity up to 10%. Being the most important drug target, a 3-D structure of HBV polymerase (Pol/RT) was modeled and docked with the active compounds, including lamivudine as standard. Docking of lamivudine indicated strong interaction with the modeled HBV Pol active-site residues that formed stable complex (∆G = −5.2 kcal/mol). Similarly, all the docked antiviral compounds formed very stable complexes with HBV Pol (∆G = −6.1 to −9.3 kcal/mol). Taken together, our data suggest the anti-HBV potential of the tested natural compounds as novel viral Pol/RT inhibitors.
Journal Article
Isolation and Characterization of Two Chalcone Derivatives with Anti-Hepatitis B Virus Activity from the Endemic Socotraen Dracaena cinnabari (Dragon’s Blood Tree)
by
Arbab, Ahmed H.
,
Al-Dosari, Mohammed S.
,
Mothana, Ramzi A.
in
Antigens
,
antiviral
,
Biodiversity
2022
Hepatitis B virus (HBV) infection is prevalent and continues to be a global health concern. In this study, we determined the anti-hepatitis B virus (HBV) potential of the Socotra-endemic medicinal plant Dracaena cinnabari and isolated and characterized the responsible constituents. A bioassay-guided fractionation using different chromatographic techniques of the methanolic extract of D. cinnabari led to the isolation of two chalcone derivatives. Using a variety of spectroscopic techniques, including 1H-, 13C-, and 2D-NMR, these derivatives were identified as 2,4’-dihydroxy-4-methoxydihydrochalcone (compound 1) and 2,4’-dihydroxy-4-methoxyhydrochalcone (compound 2). Both compounds were isolated for the first time from the red resin (dragon’s blood) of D. cinnabari. The compounds were first evaluated for cytotoxicity on HepG2.2.15 cells and 50% cytotoxicity concentration (CC50) values were determined. They were then evaluated for anti-HBV activity against HepG2.2.15 cells by assessing the suppression of HBsAg and HBeAg production in the culture supernatants and their half maximum inhibitory concentration (IC50) and therapeutic index (TI) values were determined. Compounds 1 and 2 indicated inhibition of HBsAg production in a dose- and time-dependent manner with IC50 values of 20.56 and 6.36 μg/mL, respectively.
Journal Article
Organosulfurs, S-allyl cysteine and N-acetyl cysteine sequester di-carbonyls and reduces carbonyl stress in HT22 cells
2023
Diabetes, characterized by high blood glucose level, is a progressive metabolic disease that leads to serious health complications. One of the major pathological consequences associated with diabetes is the accumulation of highly reactive carbonyl compounds called advanced glycation end products (AGEs). Most of the AGEs are dicarbonyls and have the potential to covalently modify proteins especially at the lysine residues in a non-enzymatic fashion (a process termed as glycation) resulting in the functional impairment and/or toxic gain in function. Therefore, non-toxic small molecules that can inhibit glycation are of interest for the therapeutic intervention of diabetes. In the present communication, we have investigated the effect of organosulfurs (
S
-allyl cysteine, SAC and
N
-acetyl cysteine, NAC) that are major principal components of
Allium sativa
against the glycation of different proteins. We discovered that both SAC and NAC are potent anti-glycating agents. We also found that both SAC and NAC reduce ROS level and inhibit apoptosis caused by protein glycation.
Journal Article
Expanding the clinical and genetic heterogeneity of hereditary disorders of connective tissue
by
Alfadhel, Majid
,
Kircher, Martin
,
Shendure, Jay
in
Amino Acid Sequence
,
Biomedical and Life Sciences
,
Biomedicine
2016
Ehlers–Danlos syndrome (EDS) describes a group of clinical entities in which the connective tissue, primarily that of the skin, joint and vessels, is abnormal, although the resulting clinical manifestations can vary widely between the different historical subtypes. Many cases of hereditary disorders of connective tissue that do not seem to fit these historical subtypes exist. The aim of this study is to describe a large series of patients with inherited connective tissue disorders evaluated by our clinical genetics service and for whom a likely causal variant was identified. In addition to clinical phenotyping, patients underwent various genetic tests including molecular karyotyping, candidate gene analysis, autozygome analysis, and whole-exome and whole-genome sequencing as appropriate. We describe a cohort of 69 individuals representing 40 families, all referred because of suspicion of an inherited connective tissue disorder by their primary physician. Molecular lesions included variants in the previously published disease genes
B3GALT6
,
GORAB
,
ZNF469
,
B3GAT3
,
ALDH18A1
,
FKBP14
,
PYCR1
,
CHST14
and
SPARC
with interesting variations on the published clinical phenotypes. We also describe the first recessive EDS-like condition to be caused by a recessive
COL1A1
variant. In addition, exome capture in a familial case identified a homozygous truncating variant in a novel and compelling candidate gene,
AEBP1
. Finally, we also describe a distinct novel clinical syndrome of cutis laxa and marked facial features and propose
ATP6V1E1
and
ATP6V0D2
(two subunits of vacuolar ATPase) as likely candidate genes based on whole-genome and whole-exome sequencing of the two families with this new clinical entity. Our study expands the clinical spectrum of hereditary disorders of connective tissue and adds three novel candidate genes including two that are associated with a highly distinct syndrome.
Journal Article
Quantitative analysis of rutin, quercetin, naringenin, and gallic acid by validated RP- and NP-HPTLC methods for quality control of anti-HBV active extract of Guiera senegalensis
2017
Context:Guiera senegalensis J.F. Gmel (Combretaceae) is a folk medicinal plant used in various metabolic and infectious diseases. In addition to its antiviral activities against herpes and fowlpox, the anti-HBV efficacy is very recently reported.Objective: To develop and validate simple, sensitive RP-/NP-HPTLC methods for quantitative determination of biomarkers rutin, quercetin, naringenin, and gallic acid in the anti-HBV active G. senegalensis leaves ethanol-extract.Materials and methods: RP-HPTLC (rutin & quercetin; phase- acetonitrile:water, 4:6) and NP-HPTLC (naringenin & gallic acid; phase- toluene:ethyl acetate:formic acid, 6:4:0.8) were performed on glass-backed silica gel plates 60F254-RP18 and 60F254, respectively. The methods were validated according to the ICH guidelines.Results: Well-separated and compact spots (Rf) of rutin (0.52 ± 0.006), quercetin (0.23 ± 0.005), naringenin (0.56 ± 0.009) and gallic acid (0.28 ± 0.006) were detected. The regression equations (Y) were 12.434x + 443.49, 10.08x + 216.85, 11.253x + 973.52 and 11.082x + 446.41 whereas the coefficient correlations (r2) were 0.997 ± 0.0004, 0.9982 ± 0.0001, 0.9974 ± 0.0004 and 0.9981 ± 0.0001, respectively. The linearity ranges (ng/spot) were 200–1400 (RP-HPTLC) and 100–1200 (NP-HPTLC). The LOD/LOQ (ng/band) were 33.03/100.1 (rutin), 9.67/29.31 (quercetin), 35.574/107.8 (naringenin), and 12.32/37.35 (gallic acid). Gallic acid (7.01 μg/mg) was the most abundant biomarker compared to rutin (2.42 μg/mg), quercetin (1.53 μg/mg) and naringenin (0.14 μg/mg) in the extract.Conclusion: The validated NP-/RP-HPTLC methods were simple, accurate, and sensitive for separating and quantifying antiviral biomarkers in G. senegalensis, and endorsed its anti-HBV activity. The developed methods could be further employed in the standardization and quality-control of herbal formulations.
Journal Article
The anti‑hepatitis B virus activity of sea buckthorn is attributed to quercetin, kaempferol and isorhamnetin
by
Al-Dosari, Mohammed S
,
Parvez, Mohammad K
,
Basudan, Omar A
in
Acetic acid
,
Acids
,
Amino acids
2022
The present study assessed the in vitro anti-hepatitis B virus (HBV) effects of cold-adapted sea buckthorn (Hippophae rhamnoides). Sea buckthorn leaf ethanol extracts subjected to chloroform (SB-Chl), ethyl acetate (SB-Eac), n-butanol (SB-But) and aqueous (SB-Aqu) fractionation were first examined (MTT assay) for their toxic effects on HepG2 cells. While SB-Chl (IC50, 32.58 µg/ml) exhibited high cytotoxicity, SB-Eac, SB-But SB-Aqu were non-toxic at up to 150 µg/ml. High performance liquid chromatography analysis led to the identification of the anti-HBV active flavonols, quercetin (93.09 µg/g), kaempferol (44.19 µg/g) and isorhamnetin (138.75 µg/g) in the extract. The analysis of the anti-HBV effects of SB-Eac, SB-But and SB-Aqu (50 µg/ml, each) on HepG2.2.15 cells revealed the marked inhibition of HBsAg and HBeAg expression levels. At the concentration of 10 µg/ml, quercetin and kaempferol exerted potent inhibitory effects on HBsAg (60.5 and 62.3%, respectively) and HBeAg synthesis (64.4 and 60.2%, respectively), as compared to isorhamnetin (30.5 and 28.4%, respectively). The HBV-polymerase inhibitor drug, lamivudine (2 µM), inhibited HBsAg and HBeAg expression by 87.4 and 83.5%, respectively. The data were in good agreement with a previous in vitro and in silico molecular docking analysis performed by the authors where quercetin, kaempferol and lamivudine had formed stable complexes with HBV-polymerase binding-pocket amino acids. On the whole, to the best of our knowledge, the present study provides the first report of the anti-HBV therapeutic potential of sea buckthorn, attributed to quercetin, kaempferol and isorhamnetin.
Journal Article
Mutation in MPDZ causes severe congenital hydrocephalus
2013
Background Congenital hydrocephalus is an important birth defect that is heterogeneous in aetiology and clinical presentation. Although genetics is believed to play an important role in the aetiology of non-syndromic congenital hydrocephalus, the overwhelming majority of cases lack mutations in L1CAM, the only disease gene identified to date. The purpose of this study is to identify a novel genetic cause of congenital hydrocephalus. Methods Families with congenital hydrocephalus were phenotyped clinically and, in one family, autoyzogisty mapping and linkage analysis were pursued. Sequencing of the genes within the candidate locus was followed by targeted sequencing of the likely candidate gene in two other families. Results We have identified a family in which severe congenital hydrocephalus of the communicating type follows an autosomal recessive mode of inheritance. Linkage analysis and autozygosity mapping narrowed the critical interval to 6.9 Mb on 9p24.1–p22.3 spanning just six genes. Direct sequencing of these genes revealed a truncating mutation in MPDZ, encoding a tight junction protein. Remarkably, we have also identified the same founder mutation in a stillbirth with massive congenital hydrocephalus from another family. Conclusions Our data strongly support the candidacy of MPDZ as a novel congenital hydrocephalus disease gene.
Journal Article
Novel anti‑hepatitis B virus flavonoids sakuranetin and velutin from Rhus retinorrhoea
by
Ahmed, Sarfaraz
,
Al-Dosari, Mohammed S
,
Abdelwahid, Mazin A.S
in
Adefovir dipivoxil
,
anti-HBV
,
Antibodies - pharmacology
2023
Drug-resistance in hepatitis B virus (HBV), especially due to prolonged treatment with nucleoside analogs, such as lamivudine (LAM), remains a clinical challenge. Alternatively, several plant products and isolated phytochemicals have been used as promising anti-HBV therapeutics with no sign of resistance. Among all known Rhus species, R. coriaria, R. succedanea and R. tripartite have been widely studied for their anti-HBV efficacy, however, the effects of R. retinorrhoea have not been previously investigated. The current study reported the isolation of two flavonoids, namely sakuranetin (SEK) and velutin (VEL), from the dichloromethane fraction of R. retinorrhoea aerial parts using chromatography and spectral analyses. The two flavonoids (6.25-50 µg/ml) were pre-tested for non-hepatocytotoxicity using an MTT assay and their dose- and time-dependent inhibitory activities against HBV [hepatitis B surface antigen (HBsAg) and hepatitis B 'e' antigen (HBeAg)] in cultured HepG2.2.15 cells were assessed by ELISA. SEK and VEL at the selected doses (12.5 µg/ml) significantly inhibited HBsAg by ~58.8 and ~56.4%, respectively, and HBeAg by ~55.5 and ~52.4%, respectively, on day 5. The reference drugs LAM and quercetin (anti-HBV flavonoids), suppressed the production of HBsAg/HBeAg by ~86.4/~64 and ~84.5/~62%, respectively. Furthermore, molecular docking of the flavonoids with HBV polymerase and capsid proteins revealed the formation of stable complexes with good docking energies, thus supporting their structure-based antiviral mechanism. In conclusion, the present study was the first to demonstrate the anti-HBV therapeutic activities of SEK and VEL isolated from R. retinorrhoea.
Journal Article