MyMedR

Displaying publications 81 - 100 of 177 in total

Abstract:

Sort:

Fulltext Identification and characterisation of a novel anti-viral peptide against avian influenza virus H9N2

Rajik M, Jahanshiri F, Omar AR, Ideris A, Hassan SS, Yusoff K

Virol J, 2009;6:74.
PMID: 19497129 DOI: 10.1186/1743-422X-6-74

Avian influenza viruses (AIV) cause high morbidity and mortality among the poultry worldwide. Their highly mutative nature often results in the emergence of drug resistant strains, which have the potential of causing a pandemic. The virus has two immunologically important glycoproteins, hemagglutinin (HA), neuraminidase (NA), and one ion channel protein M2 which are the most important targets for drug discovery, on its surface. In order to identify a peptide-based virus inhibitor against any of these surface proteins, a disulfide constrained heptapeptide phage display library was biopanned against purified AIV sub-type H9N2 virus particles.

Matched MeSH terms: Drug Evaluation, Preclinical
Fulltext In vitro screening of anti-lice activity of Pongamia pinnata leaves

Anbu Jeba Sunilson JS, Suraj R, Rejitha G, Anandarajagopal K, Vimala AG, Husain HA

Korean J Parasitol, 2009 Dec;47(4):377-80.
PMID: 19967085 DOI: 10.3347/kjp.2009.47.4.377

Growing patterns of pediculocidal drug resistance towards head louse laid the foundation for research in exploring novel anti-lice agents from medicinal plants. In the present study, various extracts of Pongamia pinnata leaves were tested against the head louse Pediculus humanus capitis. A filter paper diffusion method was conducted for determining the potential pediculocidal and ovicidal activity of chloroform, petroleum ether, methanol, and water extracts of P. pinnata leaves. The findings revealed that petroleum ether extracts possess excellent anti-lice activity with values ranging between 50.3% and 100% where as chloroform and methanol extracts showed moderate pediculocidal effects. The chloroform and methanol extracts were also successful in inhibiting nymph emergence and the petroleum ether extract was the most effective with a complete inhibition of emergence. Water extract was devoid of both pediculocidal and ovicidal activities. All the results were well comparable with benzoyl benzoate (25% w/v). These results showed the prospect of using P. pinnata leave extracts against P. humanus capitis in difficult situations of emergence of resistance to synthetic anti-lice agents.

Matched MeSH terms: Drug Evaluation, Preclinical
Fulltext Status of vaccine research and development of vaccines for Nipah virus

Satterfield BA, Dawes BE, Milligan GN

Vaccine, 2016 06 03;34(26):2971-2975.
PMID: 26973068 DOI: 10.1016/j.vaccine.2015.12.075

Nipah virus (NiV) is a highly pathogenic, recently emerged paramyxovirus that has been responsible for sporadic outbreaks of respiratory and encephalitic disease in Southeast Asia. High case fatality rates have also been associated with recent outbreaks in Malaysia and Bangladesh. Although over two billion people currently live in regions in which NiV is endemic or in which the Pteropus fruit bat reservoir is commonly found, there is no approved vaccine to protect against NiV disease. This report examines the feasibility and current efforts to develop a NiV vaccine including potential hurdles for technical and regulatory assessment of candidate vaccines and the likelihood for financing.

Matched MeSH terms: Drug Evaluation, Preclinical
A Real-Time Cell Analyzing Assay for Identification of Novel Antiviral Compounds against Chikungunya Virus

Zandi K

Methods Mol Biol, 2016;1426:255-62.
PMID: 27233278 DOI: 10.1007/978-1-4939-3618-2_23

Screening of viral inhibitors through induction of cytopathic effects (CPE) by conventional method has been applied for various viruses including Chikungunya virus (CHIKV), a significant arbovirus. However, it does not provide the information about cytopathic effect from the beginning and throughout the course of virus replication. Conventionally, most of the approaches are constructed on laborious end-point assays which are not capable for detecting minute and rapid changes in cellular morphology. Therefore, we developed a label-free and dynamical method for monitoring the cellular features that comprises cell attachment, proliferation, and viral cytopathogenicity, known as the xCELLigence real-time cell analysis (RTCA). In this chapter, we provide a RTCA protocol for quantitative analysis of CHIKV replication using an infected Vero cell line treated with ribavirin as an in vitro model.

Matched MeSH terms: Drug Evaluation, Preclinical
Fulltext Understanding the physicochemical properties of mitragynine, a principal alkaloid of Mitragyna speciosa, for preclinical evaluation

Ramanathan S, Parthasarathy S, Murugaiyah V, Magosso E, Tan SC, Mansor SM

Molecules, 2015 Mar 18;20(3):4915-27.
PMID: 25793541 DOI: 10.3390/molecules20034915

Varied pharmacological responses have been reported for mitragynine in the literature, but no supportive scientific explanations have been given for this. These studies have been undertaken without a sufficient understanding of the physicochemical properties of mitragynine. In this work a UV spectrophotometer approach and HPLC-UV method were employed to ascertain the physicochemical properties of mitragynine. The pKa of mitragynine measured by conventional UV (8.11 ± 0.11) was in agreement with the microplate reader determination (8.08 ± 0.04). Mitragynine is a lipophilic alkaloid, as indicated by a logP value of 1.73. Mitragynine had poor solubility in water and basic media, and conversely in acidic environments, but it is acid labile. In an in vitro dissolution the total drug release was higher for the simulated gastric fluid but was prolonged and incomplete for the simulated intestinal fluid. The hydrophobicity, poor water solubility, high variability of drug release in simulated biological fluids and acid degradable characteristics of mitragynine probably explain the large variability of its pharmacological responses reported in the literature. The determined physicochemical properties of mitragynine will provide a basis for developing a suitable formulation to further improve its solubility, stability and oral absorption for better assessment of this compound in preclinical studies.

Matched MeSH terms: Drug Evaluation, Preclinical
Fulltext Single-dose oral ampicillin in the treatment of gonococcal urethritis in males

Bakar R, Lim VKE

Med J Malaysia, 1981 Dec;36(4):202-4.
PMID: 7334952

One hundred and eight consecutive previously untreated males with gonococcal urethritis were treated with single-dose oral ampicillin under supervision. A high failure-rate of 41.5 percent was obtained. The main cause of failure was the high incidence of penicillinase-producing Neisseria gonorrhoeae - an overall incidence of 37.2 percent was obtained.

Matched MeSH terms: Drug Evaluation
Omeprazole in acute and long-term treatment of Asian patients with peptic ulcer refractory to H2-antagonists

Chelvam P, Wong EC

J Gastroenterol Hepatol, 1989;4 Suppl 2:75-81.
PMID: 2577478

Twenty-seven patients with peptic ulcer (19 with duodenal ulcer (DU) and eight with gastric ulcer (GU] refractory to H2-antagonists were treated with 40 mg of omeprazole once daily for 4-8 weeks, depending on the rate of ulcer healing. Clinical assessment, endoscopy and laboratory tests were performed at entry, after 2 and after 4 weeks, and if unhealed, also after 8 weeks' treatment. Ten healed patients were given a maintenance therapy of omeprazole 20 mg daily for up to 12 months during which the patients returned for endoscopy, gastric biopsy and laboratory tests at 3-monthly intervals. The initial treatment healed 15 of 19 (79%) DU patients in 2 weeks and all DU patients by 4 weeks. Seven of eight (87%) GU patients healed in 4 weeks and only one required 8 weeks' treatment. Symptom relief was rapid, with most patients being symptom-free within the first day of treatment. Six patients received 12 months' continuous maintenance therapy, one patient 9 months and three patients 6 months' treatment. All patients remained in remission whilst on omeprazole therapy. No adverse events were reported throughout the study. There were no clinically significant changes in haematology or blood chemistry after healing or during the long-term treatment. Biopsy samples revealed no histological changes in the gastric mucosa at any stage. Omeprazole 40 mg therefore was found to produce rapid healing and symptom relief in Asian patients with H2-antagonist-resistant peptic ulcers. Maintenance therapy with omeprazole 20 mg daily was shown to be safe and effective in preventing recurrence of peptic ulceration.

Matched MeSH terms: Drug Evaluation
Albendazole, an effective single dose, broad spectrum anthelmintic drug

Ramalingam S, Sinniah B, Krishnan U

Am J Trop Med Hyg, 1983 Sep;32(5):984-9.
PMID: 6625078

Albendazole, a new anthelmintic drug was evaluated in Malaysia in 91 patients, with single or mixed infections of Ascaris, Trichuris, and hookworm. Albendazole was administered as a single dose of 400 mg, 600 mg, or 800 mg. The cure rate for Ascaris at all three doses was 100% at days 14 and 21 post-treatment; for hookworm it was 98.8%, 100% and 98%, respectively, at day 14 and 68.8%, 100% and 84%, respectively, at day 21; for Trichuris it was 31.2%, 57.1% and 42.3%, respectively, at day 14 and 27.3%, 60.9% and 48.0%, respectively, at day 21. The egg reduction rate at day 21 was 100% at all three doses for Ascaris, 94.5%, 100% and 96.1%, respectively, for hookworm; and 39.2%, 85.1% and 72.8%, respectively, for Trichuris. There were no side effects, and biochemical examination of blood and urine did not indicate any unfavourable changes. Based on this trial, the recommended dosage for Ascaris and hookworm is a 400 mg single dose, and for Trichuris is a 600 mg single dose. Albendazole appears to be more effective than other available anthelmintic drugs.

Matched MeSH terms: Drug Evaluation
An open clinical trial comparing (paired comparisons) desoximetasone with betamethasone 17-valerate

Adam BA

Med J Malaysia, 1978 Jun;32(4):302-3.
PMID: 732627
Matched MeSH terms: Drug Evaluation
Studies on the resistance of malaria to chloroquine and to a combination of chloroquine and pyrimethamine in Peninsular Malaysia

Dondero TJ, Parsons RE, Ponnampalam JT

Trans R Soc Trop Med Hyg, 1976;70(2):145-8.
PMID: 785725

In vivo chloroquine resistance surveys, which allowed for detection of late recrudescing RI resistance, were conducted in three regions of Peninsular Malaysia, which were previously not recognized as having appreciable drug resistance. Among the 485 Plasmodium falciparum infections tested resistance rates ranged locally from 20% to 67% in those with parasitaemias over 1,000 per mm3, and 5% to 59% in all parasitaemias. The region found to have the most serious resistance was western Pahang. In one study a combination of chloroquine and pyrimethamine proved no more efficacious than chloroquine alone. Most of the resistance encountered was the late recrudescing RI type. There was no apparent correlation between drug resistance and Anopheles balabacensis as this species was not found despite intensive collections in two of the three main regions. There was no evidence of resistance among the 222 P. vivax and 35 P. malariae infections also tested.

Matched MeSH terms: Drug Evaluation
"Catapres in the management of hypertension"

Singh N, Menon V

Med J Malaysia, 1975 Mar;30(3):209-13.
PMID: 1160681
Matched MeSH terms: Drug Evaluation
Fulltext 3D Microfluidic Bone Tumor Microenvironment Comprised of Hydroxyapatite/Fibrin Composite

Ahn J, Lim J, Jusoh N, Lee J, Park TE, Kim Y, et al.

Front Bioeng Biotechnol, 2019;7:168.
PMID: 31380359 DOI: 10.3389/fbioe.2019.00168

Bone is one of the most common sites of cancer metastasis, as its fertile microenvironment attracts tumor cells. The unique mechanical properties of bone extracellular matrix (ECM), mainly composed of hydroxyapatite (HA) affect a number of cellular responses in the tumor microenvironment (TME) such as proliferation, migration, viability, and morphology, as well as angiogenic activity, which is related to bone metastasis. In this study, we engineered a bone-mimetic microenvironment to investigate the interactions between the TME and HA using a microfluidic platform designed for culturing tumor cells in 3D bone-mimetic composite of HA and fibrin. We developed a bone metastasis TME model from colorectal cancer (SW620) and gastric cancer (MKN74) cells, which has very poor prognosis but rarely been investigated. The microfluidic platform enabled straightforward formation of 3D TME composed the hydrogel and multiple cell types. This facilitated monitoring of the effect of HA concentration and culture time on the TME. In 3D bone mimicking culture, we found that HA rich microenvironment affects cell viability, proliferation and cancer cell cytoplasmic volume in a manner dependent on the different metastatic cancer cell types and culture duration indicating the spatial heterogeneity (different origin of metastatic cancer) and temporal heterogeneity (growth time of cancer) of TME. We also found that both SW620 and MKN72 cells exhibited significantly reduced migration at higher HA concentration in our platform indicating inhibitory effect of HA in both cancer cells migration. Next, we quantitatively analyzed angiogenic sprouts induced by paracrine factors that secreted by TME and showed paracrine signals from tumor and stromal cell with a high HA concentration resulted in the formation of fewer sprouts. Finally we reconstituted vascularized TME allowing direct interaction between angiogenic sprouts and tumor-stroma microspheroids in a bone-mimicking microenvironment composing a tunable HA/fibrin composite. Our multifarious approach could be applied to drug screening and mechanistic studies of the metastasis, growth, and progression of bone tumors.

Matched MeSH terms: Drug Evaluation, Preclinical
Fulltext Evaluation of Chondroprotective Activity of Channa striatus in Rabbit Osteoarthritis Model

Abdul Kadir A, Abdul Kadir A, Abd Hamid R, Mat Jais AM, Omar J, Sadagatullah AN, et al.

Biomed Res Int, 2019;2019:6979585.
PMID: 31355276 DOI: 10.1155/2019/6979585

Objectives: The objective of the study is to evaluate the chondroprotective activity of Channa striatus (Channa) and glucosamine sulphate (glucosamine) on histomorphometric examinations, serum biomarker, and inflammatory mediators in experimental osteoarthritis (OA) rabbit model.
Design: Anterior cruciate ligament transection (ACLT) was performed to induce OA in thirty-three male New Zealand white rabbits and were randomly divided into three groups: Channa, glucosamine, and control group. The control group received drinking water and the Channa and glucosamine groups were orally administered with 51.4 mg/kg of Channa extract and 77.5 mg/kg of glucosamine sulphate in drinking water, respectively, for eight weeks and then sacrificed. The articular cartilage was evaluated macroscopically and histologically using semiquantitative and quantitative methods. Serum cartilage oligomeric matric protein (COMP), cyclooxygenase 2 (COX-2) enzyme, and prostaglandin E2 (PGE2) were also determined.
Results: Macroscopic analysis revealed that Channa group have a significantly lower severity grade of total macroscopic score compared to the control (p < 0.001) and glucosamine (p < 0.05) groups. Semiquantitative histology scoring showed that both Channa and glucosamine groups had lower severity grading of total histology score compared to the control group (p < 0.001). In comparison with the control, Channa group had lower histopathological changes in three compartments of the joint compared to glucosamine group which had lower histological scoring in two compartments only. The cartilage thickness, area, and roughness of both Channa (p < 0.05) and glucosamine (p < 0.05) groups were superior compared to the control group. However, the Channa group demonstrated significantly less cartilage roughness compared to the glucosamine group (p < 0.05). Serum COMP levels were lower in both Channa (p < 0.05) and glucosamine (p < 0.05) groups compared to the control group.
Conclusion: Both oral administration of Channa extract and glucosamine exhibited chondroprotective action on an ACLT OA-induced rabbit model. However, Channa was superior to glucosamine in maintaining the structure of the cartilage.

Matched MeSH terms: Drug Evaluation, Preclinical
Applications of Ensemble Docking in Potential Inhibitor Screening for Mycobacterium tuberculosis Isocitrate Lyase Using a Local Plant Database

Lee YV, Choi SB, Wahab HA, Lim TS, Choong YS

J Chem Inf Model, 2019 05 28;59(5):2487-2495.
PMID: 30840452 DOI: 10.1021/acs.jcim.8b00963

Isocitrate lyase (ICL) is a persistent factor for the survival of dormant stage Mycobacterium tuberculosis (MTB), thus a potential drug target for tuberculosis treatment. In this work, ensemble docking approach was used to screen for potential inhibitors of ICL. The ensemble conformations of ICL active site were obtained from molecular dynamics simulation on three dimer form systems, namely the apo ICL, ICL in complex with metabolites (glyoxylate and succinate), and ICL in complex with substrate (isocitrate). Together with the ensemble conformations and the X-ray crystal structures, 22 structures were used for the screening against Malaysian Natural Compound Database (NADI). The top 10 compounds for each ensemble conformation were selected. The number of compounds was then further narrowed down to 22 compounds that were within the Lipinski's Rule of Five for drug-likeliness and were also docked into more than one ensemble conformation. Theses 22 compounds were furthered evaluate using whole cell assay. Some compounds were not commercially available; therefore, plant crude extracts were used for the whole cell assay. Compared to itaconate (the known inhibitor of ICL), crude extracts from Manilkara zapota, Morinda citrifolia, Vitex negundo, and Momordica charantia showed some inhibition activity. The MIC/MBC value were 12.5/25, 12.5/25, 0.78/1.6, and 0.39/1.6 mg/mL, respectively. This work could serve as a preliminary study in order to narrow the scope for high throughput screening in the future.

Matched MeSH terms: Drug Evaluation, Preclinical
Synthesis of 2-methoxybenzoylhydrazone and evaluation of their antileishmanial activity

Taha M, Baharudin MS, Ismail NH, Khan KM, Jaafar FM, Samreen, et al.

Bioorg Med Chem Lett, 2013 Jun 1;23(11):3463-6.
PMID: 23608761 DOI: 10.1016/j.bmcl.2013.03.051

Compounds 1-25 showed varying degree of antileishmanial activities with IC50 values ranging between 1.95 and 88.56 μM. Compounds 2, 10, and 11 (IC50=3.29±0.07 μM, 1.95±0.04 μM, and 2.49±0.03 μM, respectively) were found to be more active than standard pentamidine (IC50=5.09±0.04 μM). Compounds 7 (IC50=7.64±0.1 μM), 8 (IC50=13.17±0.46 μM), 18 (IC50=13.15±0.02 μM), and 24 (IC50=15.65±0.41 μM) exhibited good activities. Compounds 1, 3, 4, 5, 9, 12, 15, 18, and 19 were found to be moderately active. Compounds 13, 14, 16, 17, 20-25 showed weak activities with IC50 values ranging between 57 and 88 μM.

Matched MeSH terms: Drug Evaluation, Preclinical
Computational pharmacology and bioinformatics to explore the potential mechanism of Schisandra against atherosclerosis

Duan H, Khan GJ, Shang LJ, Peng H, Hu WC, Zhang JY, et al.

Food Chem Toxicol, 2021 Apr;150:112058.
PMID: 33582168 DOI: 10.1016/j.fct.2021.112058

The present study uses network pharmacology to study the potential mechanism of Schisandra against atherosclerosis. Drug-disease targets were explored through the traditional Chinese medicine systemic pharmacology network. STRING database and Cytoscape software were employed to construct a component/pathway-target interaction network to screen the key regulatory factors from Schisandra. For cellular, biological and molecular pathways, Gene Ontology (GO) and KEGG pathway analyses were used while the interceptive acquaintances of the pathways was obtained through Metascape database. Initial molecular docking analyses of components from Schisandra pointed the possible interaction of non-muscle myosin ⅡA (NM ⅡA) against atherosclerosis. The screening results from GO and KEGG identified 525 possible targets of 18 active ingredients from Schisandra that further pointed 1451 possible pathways against the pathogenesis of disease whereas 167 targets were further refined based on common/interesting signaling target pathways. Further results of molecular signaling by docking identified very compatible binding between NM IIA and the constituents of Schisandra. Schisandra has a possible target of the serotonergic synapse, neuroactive ligand-receptor interaction and also has close interference in tumor pathways through PTGS2, NOS3, HMOX1 and ESR1. Moreover, it is also concluded that Schisandra has a close association with neuroendocrine, immune-inflammation and oxidative stress. Therefore, it may have the potential of therapeutic utility against atherosclerosis.

Matched MeSH terms: Drug Evaluation, Preclinical
Interference Potential of Tannins and Chlorophylls in Zebrafish Phenotypic-Based Assays

Samat N, Ng MF, Ruslan NF, Okuda KS, Tan PJ, Patel V

Assay Drug Dev Technol, 2018 10;16(7):408-419.
PMID: 29985634 DOI: 10.1089/adt.2017.833

Natural products are prolific producers of diverse chemical scaffolds, which have yielded several clinically useful drugs. However, the complex features of natural products present challenges for identifying bioactive molecules using high-throughput screens. For most assays, measured endpoints are either colorimetric or luminescence based. Thus, the presence of the major metabolites, tannins, and chlorophylls, in natural products could potentially interfere with these measurements to give either false-positive or false-negative hits. In this context, zebrafish phenotypic assays provide an alternative approach to bioprospect naturally occurring bioactive compounds. Whether tannins and/or chlorophylls interfere in zebrafish phenotypic assays, is unclear. In this study, we evaluated the interference potential of tannins and chlorophylls against efficacy of known small-molecule inhibitors that are known to cause phenotypic abnormalities in developing zebrafish embryos. First, we fractionated tannin-enriched fraction (TEF) and chlorophyll-enriched fraction (CEF) from Camellia sinensis and cotreated them with PD0325901 [mitogen-activated protein kinase-kinase (MEK) inhibitor] and sunitinib malate (SM; anti-[lymph]angiogenic drug). While TEF and CEF did not interfere with phenotypic or molecular endpoints of PD0325901, TEF at 100 μg/mL partially masked the antiangiogenic effect of SM. On the other hand, CEF (100 μg/mL) was toxic when treated up to 6 dpf. Furthermore, CEF at 100 μg/mL potentially enhanced the activity of γ-secretase inhibitors, resulting in toxicity of treated embryos. Our study provides evidence that the presence of tannin and/or chlorophyll in natural products do interfere with zebrafish phenotype assays used for identifying potential hits. However, this may be target/assay dependent and thus requiring additional optimization steps to assess interference potential of tannins and chlorophylls before performing any screening assay.

Matched MeSH terms: Drug Evaluation, Preclinical
Fulltext Pathological findings in a mouse model for Coxsackievirus A16 infection

Hooi, Yuan Teng, Ong, Kien Chai, Perera, David, Wong, Kum Thong

Neurology Asia, 2015;20(4):343-347.
MyJurnal

Coxsackievirus A16 (CV-A16) is the leading cause of hand-foot-mouth disease (HFMD), which usually
presents as mild and self-limiting symptoms in young children. Rarely, CV-A16 has been reported
to cause severe and fatal neurological complications but little is known about these complications.
In the present study, 1-day and 7-day old mouse models of CV-A16 were developed using a clinical
strain via subcutaneous inoculation. All infected mice exhibited clinical signs of infection, including
reduced mobility, limb weakness and paralysis between 3 to 6 days post-infection. Pathologically,
the main organs involved were the central nervous system (CNS), skeletal muscles and brown fat. In
the CNS, viral antigens as demonstrated by immunohistochemistry, were localized mainly to neurons
in the brain stem and spinal cord, suggesting that CV-A16 is neurotropic although inflammation is
very mild. The skeletal muscles showed necrosis and myositis due to viral infection as evidenced by
the dense viral antigens. Focal viral antigens were also detected in the brown fat. These preliminary
pathological findings indicate that our mouse models can be further developed to be useful models
for pathogenesis studies, and vaccine and anti-viral drug evaluation.

Matched MeSH terms: Drug Evaluation
Lorazepam in patients with mixed psychic and somatic symptoms

Sundarm K, Lumpur K

Med J Malaysia, 1975 Mar;30(3):214-8.
PMID: 240111
Matched MeSH terms: Drug Evaluation
New cembrane-type diterpenoids from Bornean soft coral Nephthea sp. with antifungal activity against Lagenidium thermophilum

Tani K, Kamada T, Phan CS, Vairappan CS

Nat Prod Res, 2019 Dec;33(23):3343-3349.
PMID: 29772929 DOI: 10.1080/14786419.2018.1475387

Three new cembrane diterpenes, nephthecrassocolides A-B (1-2) and 6-acetoxy nephthenol acetate (3) along with three known compounds, 6-acetoxy-7,8-epoxy nephthenol acetate (4), epoxy nephthenol acetate (5) and nephthenol (6) were isolated from one population of Nephthea sp. Their structures were elucidated based on spectroscopic data analysis and the antifungal activities of compounds 1-6 were evaluated.

Matched MeSH terms: Drug Evaluation, Preclinical

Filters

Please provide feedback to Administrator ([email protected])

External Links