Displaying publications 41 - 60 of 276 in total

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  1. Ang HH, Chan KL, Mak JW
    Folia Parasitol., 1998;45(3):196-8.
    PMID: 9805783
    Five Malaysian isolates of the protozoan Plasmodium falciparum Welch were cultured in vitro following the method of Trager and Jensen (1976, 1977) and subsequently cloned using the limiting dilution method of Rosario (1981). Thirty clones were obtained and were later characterized against schizontocidal drugs, chloroquine, mefloquine and quinine, using the modified in vitro microtechnique. Results showed that these local isolates were heterogeneous and most of the clones exhibited similar pattern of susceptibility as their parent isolate except for ST 168 clone and two ST 195 clones that were sensitive but two ST 165 clones, two ST 168 clones and five ST 195 clones were resistant against quinine, respectively. Results also indicated that they were pure clones compared to their parent isolate because their drug susceptibility studies were significantly different (p < 0.05).
    Matched MeSH terms: Antimalarials/pharmacology*
  2. Gilles HM
    J Infect, 1989 Jan;18(1):11-23.
    PMID: 2644358
    The epidemiology, clinical features, diagnosis, prognosis, management, chemotherapy and chemoprophylaxis of malaria are reviewed.
    Matched MeSH terms: Antimalarials/therapeutic use
  3. Lyn PC, Fernandez E
    Med J Aust, 1987 Mar 16;146(6):335-6.
    PMID: 2950306
    Matched MeSH terms: Antimalarials/adverse effects*
  4. van Schalkwyk DA, Blasco B, Davina Nuñez R, Liew JWK, Amir A, Lau YL, et al.
    PMID: 30831468 DOI: 10.1016/j.ijpddr.2019.02.004
    New antimalarial agents are identified and developed after extensive testing on Plasmodium falciparum parasites that can be grown in vitro. These susceptibility studies are important to inform lead optimisation and support further drug development. Until recently, little was known about the susceptibility of non-falciparum species as these had not been adapted to in vitro culture. The recent culture adaptation of P. knowlesi has therefore offered an opportunity to routinely define the drug susceptibility of this species, which is phylogenetically closer to all other human malarias than is P. falciparum. We compared the in vitro susceptibility of P. knowlesi and P. falciparum to a range of established and novel antimalarial agents under identical assay conditions. We demonstrated that P. knowlesi is significantly less susceptible than P. falciparum to six of the compounds tested; and notably these include three ATP4 inhibitors currently under development as novel antimalarial agents, and one investigational antimalarial, AN13762, which is 67 fold less effective against P. knowlesi. For the other compounds there was a less than two-fold difference in susceptibility between species. We then compared the susceptibility of a recent P. knowlesi isolate, UM01, to that of the well-established, older A1-H.1 clone. This recent isolate showed similar in vitro drug susceptibility to the A1-H.1 clone, supporting the ongoing use of the better characterised clone to further study drug susceptibility. Lastly, we used isobologram analysis to explore the interaction of a selection of drug combinations and showed similar drug interactions across species. The species differences in drug susceptibility reported by us here and previously, support adding in vitro drug screens against P. knowlesi to those using P. falciparum strains to inform new drug discovery and lead optimisation.
    Matched MeSH terms: Antimalarials/pharmacology*
  5. Islahudin F, Ting KN, Pleass RJ, Avery SV
    Antimicrob Agents Chemother, 2013 Nov;57(11):5787.
    PMID: 24123347 DOI: 10.1128/AAC.01688-13
    Matched MeSH terms: Antimalarials/pharmacology*
  6. Krishna S, Augustin Y, Wang J, Xu C, Staines HM, Platteeuw H, et al.
    Trends Parasitol, 2021 01;37(1):8-11.
    PMID: 33153922 DOI: 10.1016/j.pt.2020.10.003
    Artemisinin-based combination therapies (ACTs) have demonstrated in vitro inhibition of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Artemisinins have also shown anti-inflammatory effects, including inhibition of interleukin-6 (IL-6) that plays a key role in the development of severe coronavirus disease 2019 (COVID-19). There is now sufficient evidence for the effectiveness of ACTs, and in particular artesunate/pyronaridine, to support clinical studies for COVID-19 infections.
    Matched MeSH terms: Antimalarials/therapeutic use*
  7. Saad B, Zin ZM, Jab MS, Rahman IA, Saleh MI, Mahsufi S
    Anal Sci, 2005 May;21(5):521-4.
    PMID: 15913140
    Poly (vinyl chloride) membrane electrodes that responded selectively towards the antimalarial drug chloroquine are described. The electrodes were based on the use of the lipophilic potassium tetrakis(4-chlorophenyl)borate as ion-exchanger and bis(2-ethylhexyl)adipate (BEHA), or trioctylphosphate (TOP) or dioctylphenylphosphonate (DOPP) as plasticizing solvent mediator. All electrodes produced good quality characteristics such as Nernstian- and rapid responses, and are minimally interfered with by the alkali and alkaline earth metal ions tested. The membranes were next applied to a flow-through device, enabling it to function as flow-injection analysis (FIA) detector. The performance of the sensor after undergoing the FIA optimization was further evaluated for its selectivity characteristics and lifetime. Results for the determination of chloroquine in synthetic samples that contained common tablet excipients such as glucose, starch, and cellulose, and other foreign species such as cations, citric acid or lactic acid were generally satisfactory. The sensor was also successfully used for the determination of the active ingredients in mock tablets, synthetic fluids and biological fluids. The sensor was applied for the determination of active ingredients and the dissolution profile of commercial tablets was also established.
    Matched MeSH terms: Antimalarials/analysis*
  8. Chan EW, Wong SK, Chan HT
    J Integr Med, 2016 Jul;14(4):269-84.
    PMID: 27417173 DOI: 10.1016/S2095-4964(16)60261-3
    Apocynaceae is a large family of tropical trees, shrubs and vines with most species producing white latex. Major metabolites of species are triterpenoids, iridoids, alkaloids and cardenolides, which are known for a wide range of biological and pharmacological activities such as cardioprotective, hepatoprotective, neuroprotective, anti-inflammatory, anticancer and antimalarial properties. Prompted by their anticancer and antimalarial properties, the current knowledge on ten genera (Allamanda, Alstonia, Calotropis, Catharanthus, Cerbera, Dyera, Kopsia, Nerium, Plumeria and Vallaris) is updated. Major classes of metabolites are described using some species as examples. Species with antiproliferative (APF) and/or antiplasmodial (APM) properties have been identified. With the exception of the genus Dyera, nine genera of 22 species possess APF activity. Seven genera (Alstonia, Calotropis, Catharanthus, Dyera, Kopsia, Plumeria and Vallaris) of 13 species have APM properties. Among these species, Alstonia angustiloba, Alstonia macrophylla, Calotropis gigantea, Calotropis procera, Catharanthus roseus, Plumeria alba and Vallaris glabra displayed both APF and APM properties. The chemical constituents of these seven species are compiled for assessment and further research.
    Matched MeSH terms: Antimalarials/pharmacology*
  9. Naserrudin NA, Jiee SF, Habil B, Jantim A, Mohamed AFB, Dony JJF, et al.
    Malar J, 2023 Oct 03;22(1):292.
    PMID: 37789320 DOI: 10.1186/s12936-023-04693-1
    BACKGROUND: Since 2018, no indigenous human malaria cases has been reported in Malaysia. However, during the recent COVID-19 pandemic the World Health Organization is concerned that the pandemic might erode the success of malaria control as there are reports of increase malaria cases in resource limited countries. Little is known how the COVID-19 pandemic has impacted malaria in middle-income countries like Malaysia. Here the public health response to a Plasmodium malariae outbreak occurred in a village in Sabah state, Malaysia, during a COVID-19 movement control order is reported.

    METHODS: An outbreak was declared following the detection of P. malariae in July 2020 and active case detection for malaria was performed by collecting blood samples from residents residing within 2 km radius of Moyog village. Vector prevalence and the efficacy of residual insecticides were determined. Health awareness programmes were implemented to prevent future outbreaks. A survey was conducted among villagers to understand risk behaviour and beliefs concerning malaria.

    RESULTS: A total of 5254 blood samples collected from 19 villages. Among them, 19 P. malariae cases were identified, including the index case, which originated from a man who returned from Indonesia. His return from Indonesia and healthcare facilities visit coincided with the movement control order during COVID-19 pandemic when the healthcare facilities stretched its capacity and only serious cases were given priority. Despite the index case being a returnee from a malaria endemic area presenting with mild fever, no malaria test was performed at local healthcare facilities. All cases were symptomatic and uncomplicated except for a pregnant woman with severe malaria. There were no deaths; all patients recovered following treatment with artemether-lumefantrine combination therapy. Anopheles balabacensis and Anopheles barbirostris were detected in ponds, puddles and riverbeds. The survey revealed that fishing and hunting during night, and self-treatment for mild symptoms contributed to the outbreak. Despite the index case being a returnee from a malaria-endemic area presenting with mild fever, no malaria test was performed at local healthcare facilities.

    CONCLUSION: The outbreak occurred during a COVID-19 movement control order, which strained healthcare facilities, prioritizing only serious cases. Healthcare workers need to be more aware of the risk of malaria from individuals who return from malaria endemic areas. To achieve malaria elimination and prevention of disease reintroduction, new strategies that include multisectoral agencies and active community participation are essential for a more sustainable malaria control programme.

    Matched MeSH terms: Antimalarials*
  10. Al-Adhroey AH, Nor ZM, Al-Mekhlafi HM, Amran AA, Mahmud R
    Molecules, 2010 Dec 28;16(1):107-18.
    PMID: 21189459 DOI: 10.3390/molecules16010107
    The need for new compounds active against malaria parasites is made more urgent by the rapid spread of drug-resistance to available antimalarial drugs. The crude methanol extract of Piper betle leaves (50-400 mg/kg) was investigated for its antimalarial activity against Plasmodium berghei (NK65) during early and established infections. The phytochemical and antioxidant potentials of the crude extract were evaluated to elucidate the possibilities of its antimalarial effects. The safety of the extract was also investigated in ICR mice of both sexes by the acute oral toxicity limit test. The leaf extract demonstrated significant (P < 0.05) schizonticidal activity in all three antimalarial evaluation models. Phytochemical screening showed that the leaf extract contains some vital antiplasmodial chemical constituents. The extract also exhibited a potent ability to scavenge the free radicals. The results of acute toxicity showed that the methanol extract of Piper betle leaves is toxicologically safe by oral administration. The results suggest that the Malaysian folklorical medicinal application of the extract of Piper betle leaf has a pharmacological basis.
    Matched MeSH terms: Antimalarials/pharmacology*
  11. Ramli N, Ahamed PO, Elhady HM, Taher M
    Pharmacognosy Res, 2014 Oct;6(4):280-4.
    PMID: 25276063 DOI: 10.4103/0974-8490.138248
    Malaria is a mosquito-borne disease caused by parasitic protozoa from the genus of Plasmodium. The protozoans have developed resistance against many of current drugs. It is urgent to find an alternative source of new antimalarial agent. In the effort to discover new antimalarial agents, this research has been conducted on Plectranthus amboinicus.
    Matched MeSH terms: Antimalarials
  12. Awang K, Mukhtar MR, Hadi AH, Litaudon M, Latip J, Abdullah NR
    Nat Prod Res, 2006 May 20;20(6):567-72.
    PMID: 16835089
    The alkaloidal extract of the leaves of Phoebe grandis (nees) merr. have provided two new minor alkaloids; phoebegrandine D (1), a proaporphine-tryptamine dimer, and phoebegrandine E (2), an indoloquinolizidine. This is the first report on the occurrence of an indoloquinolizidine in the Phoebe species. The crude extract also exhibited antiplasmodial activity (IC50<8 microg mL-1). The structures of the novel compounds were elucidated by spectroscopic methods, notably 2D NMR and HRMS.
    Matched MeSH terms: Antimalarials/isolation & purification*; Antimalarials/pharmacology; Antimalarials/chemistry
  13. Wani WA, Jameel E, Baig U, Mumtazuddin S, Hun LT
    Eur J Med Chem, 2015 Aug 28;101:534-51.
    PMID: 26188909 DOI: 10.1016/j.ejmech.2015.07.009
    Malaria has been teasing human populations from a long time. Presently, several classes of antimalarial drugs are available in market, but the issues of toxicity, lower efficacy and the resistance by malarial parasites have decreased their overall therapeutic indices. Thus, the search for new promising antimalarials continues, however, the battle against malaria is far from over. Ferroquine is a derivative of chloroquine with antimalarial properties. It is the most successful of the chloroquine derivatives. Not only ferroquine, but also its derivatives have shown promising potential as antimalarials of clinical interest. Presently, much research is dedicated to the development of ferroquine derivatives as safe alternatives to antimalarial chemotherapy. The present article describes the structural, chemical and biological features of ferroquine. Several classes of ferroquine derivatives including hydroxyferroquines, trioxaferroquines, chloroquine-bridged ferrocenophanes, thiosemicarbazone derivatives, ferrocene dual conjugates, 4-N-substituted derivatives, and others have been discussed. Besides, the mechanism of action of ferroquine has been discussed. A careful observation has been made into pharmacologically significant ferroquine derivatives with better or equal therapeutic effects to that of chloroquine and ferroquine. A brief discussion of the toxicities of ferroquine derivatives has been made. Finally, efforts have been made to discuss the current challenges and future perspectives of ferroquine-based antimalarial drug development.
    Matched MeSH terms: Antimalarials/chemical synthesis; Antimalarials/pharmacology*; Antimalarials/chemistry
  14. Tan HS, Tan PE
    Med J Malaysia, 1983 Sep;38(3):217-23.
    PMID: 6369092
    One hundred and ten consecutive patients with falciparum malaria were treated with Fansidar and primaquine. Of the 61 patients who were followed up at one week, 4 (6.5%) failed to clear their parasitemia (1 R III and 3 R Il treatment failures). Of the subsequent 40 patients who were seen again at one month, another 3 (7.5%) had recrudesced (R 1 treatment failure). A total of 7 patients thus experienced some form of treatment failure in the cohort of 40 who completed the one month follow up. Only 1 of these 7patients (with R III treatment) failure) failed to respond to repeat Fansidar treatment, and may be the only one with true Fansidar resistance. The overall treatment failure rate of 17.5% (95% confidence interval: 6-29%) in the cohort who completed the study is consistent with the known clinical efficacy of Fansidar. These results suggest no significant Fansidar resistance in falciparum malaria found in Sabah.
    Matched MeSH terms: Antimalarials/administration & dosage; Antimalarials/adverse effects; Antimalarials/therapeutic use*
  15. Abdullah MA, Mohd Faudzi SM, Nasir NM
    Mini Rev Med Chem, 2021;21(9):1058-1070.
    PMID: 33272171 DOI: 10.2174/1389557520999201203213957
    Medicinal chemists have continuously shown interest in new curcuminoid derivatives, diarylpentadienones, owing to their enhanced stability feature and easy preparation using a one-pot synthesis. Thus far, methods such as Claisen-Schmidt condensation and Julia- Kocienski olefination have been utilised for the synthesis of these compounds. Diarylpentadienones possess a high potential as a chemical source for designing and developing new and effective drugs for the treatment of diseases, including inflammation, cancer, and malaria. In brief, this review article focuses on the broad pharmacological applications and the summary of the structure-activity relationship of molecules, which can be employed to further explore the structure of diarylpentadienone. The current methodological developments towards the synthesis of diarylpentadienones are also discussed.
    Matched MeSH terms: Antimalarials/chemical synthesis; Antimalarials/therapeutic use*; Antimalarials/chemistry
  16. Kam MYY, Yap WSP
    Biotechnol Genet Eng Rev, 2020 Apr;36(1):1-31.
    PMID: 32308142 DOI: 10.1080/02648725.2020.1749818
    Artemisinin (ART) is an antimalarial compound that possesses a variety of novel biological activities. Due to the low abundance of ART in natural sources, agricultural supply has been erratic, and prices are highly volatile. While heterologous biosynthesis and semi-synthesis are advantageous in certain aspects, these approaches remained disadvantageous in terms of productivity and cost-effectiveness. Therefore, further improvement in ART production calls for approaches that should supplement the agricultural production gap, while reducing production costs and stabilising supply. The present review offers a discussion on the elicitation of plants and/or in vitro cultures as an economically feasible yield enhancement strategy to address the global problem of access to affordable ART. Deemed critical for the manipulation of biosynthetic potential, the mechanism of ART biosynthesis is reviewed. It includes a discussion on the current biotechnological solutions to ART production, focusing on semi-synthesis and elicitation. A brief commentary on the possible aspects that influence elicitation efficiency and how oxidative stress modulates ART synthesis is also presented. Based on the critical analysis of current literature, a hypothesis is put forward to explain the possible involvement of enzymes in assisting the final non-enzymatic transformation step leading to ART formation. This review highlights the critical factors limiting the success of elicitor-induced modulation of ART metabolism, that will help inform strategies for future improvement of ART production. Additionally, new avenues for future research based on the proposed hypothesis will lead to exciting perspectives in this research area and continue to enhance our understanding of this intricate metabolic process.
    Matched MeSH terms: Antimalarials/chemical synthesis; Antimalarials/metabolism*; Antimalarials/therapeutic use
  17. Navaratnam V, Mansor SM, Mordi MN, Akbar A, Abdullah MN
    Eur J Clin Pharmacol, 1998 Jul;54(5):411-4.
    PMID: 9754985
    OBJECTIVE: A single cross-over, comparative pharmacokinetic study of oral and rectal formulations of 200 mg artesunic acid in 12 healthy Malaysian volunteers is reported.

    METHODS: Plasma concentrations of artesunic acid and dihydroartemisinin were determined simultaneously by HPLC with electrochemical detection. The test drug was well tolerated and no undesirable adverse effects were observed.

    RESULTS: Comparison of pharmacokinetic parameters of artesunic acid after oral and rectal administration showed statistically significant differences in t(max) and AUC, with no changes for Cmax and t1/2. As for dihydroartemisinin, differences were observed for t(max) and Cmax but not for AUC.

    CONCLUSION: There appear to be pharmacokinetic differences between oral and rectal modes of administration. The significance of these findings should be explored in malaria patients before appropriate therapeutic regimens are devised.

    Matched MeSH terms: Antimalarials/administration & dosage; Antimalarials/blood; Antimalarials/pharmacokinetics*
  18. Mohd Ridzuan MA, Sow A, Noor Rain A, Mohd Ilham A, Zakiah I
    Trop Biomed, 2007 Jun;24(1):111-8.
    PMID: 17568384 MyJurnal
    Eurycoma longifolia, locally known as 'Tongkat Ali' is a popular local medicinal plant that possess a lot of medicinal properties as claimed traditionally, especially in the treatment of malaria. The claims have been proven scientifically on isolated compounds from the plant. The present study is to investigate the anti malaria properties of Eurycoma longifolia standardized extract (root) (TA164) alone and in combination with artemisinin in vivo. Combination treatment of the standardized extract (TA164) with artemisinin suppressed P. yoelii infection in the experimental mice. The 4 day suppressive test showed that TA164 suppressed the parasitemia of P. yoelii-infected mice as dose dependent manner (10, 30 and 60 mg/kg BW) by oral and subcutaneous treatment. By oral administration, combination of TA164 at 10, 30 and 60 mg/kg BW each with artemisinin respectively showed a significant increase in the parasitemia suppression to 63, 67 and 80 percent as compared to artemisinin single treatment (31%). Using subcutaneous administration, at 10 mg/kg BW of TA164 in combination with 1.7 mg/kg BW of artemisinin gave a suppression of 80% of infection. This study showed that combination treatment of TA164 with artemisinin gives a promising potential anti malaria candidate using both oral and subcutaneous route, the later being the most potent.
    Matched MeSH terms: Antimalarials/administration & dosage; Antimalarials/pharmacology; Antimalarials/chemistry
  19. Ghazali SZ, Mohamed Noor NR, Mustaffa KMF
    Prep Biochem Biotechnol, 2022;52(1):99-107.
    PMID: 33890844 DOI: 10.1080/10826068.2021.1913602
    The objective of this study is to synthesize neem-silver nitrate nanoparticles (neem-AgNPs) using aqueous extracts of Azadirachta indica A. Juss for malaria therapy. Neem leaves collected from FRIM Malaysia were authenticated and extracted using Soxhlet extraction method. The extract was introduced to 1 mM of silver nitrate solution for neem-AgNPs synthesis. Synthesized AgNPs were further characterized by ultraviolet-visible spectroscopy and the electron-scanning microscopy. Meanwhile, for the anti-plasmodial activity of the neem-AgNPs, two lab-adapted Plasmodium falciparum strains, 3D7 (chloroquine-sensitive), and W2 (chloroquine-resistant) were tested. Red blood cells hemolysis was monitored to observe the effects of neem-AgNPs on normal and parasitized red blood cells. The synthesized neem-AgNPs were spherical in shape and showed a diameter range from 31-43 nm. When compared to aqueous neem leaves extract, the half inhibitory concentration (IC50) of the synthesized neem-AgNPs showed a four-fold IC50 decrease against both parasite strains with IC50 value of 40.920 µg/mL to 8.815 µg/mL for 3D7, and IC50 value of 98.770 µg/mL to 23.110 µg/mL on W2 strain. The hemolysis assay indicates that the synthesized neem-AgNPs and aqueous extract alone do not have hemolysis activity against normal and parasitized red blood cells. Therefore, this study shows the synthesized neem-AgNPs has a great potential to be used for malaria therapy.
    Matched MeSH terms: Antimalarials/chemical synthesis; Antimalarials/pharmacology; Antimalarials/chemistry*
  20. Ramanathan S, Karupiah S, Nair NK, Olliaro PL, Navaratnam V, Wernsdorfer WH, et al.
    PMID: 16046285
    A new approach using a simple solid-phase extraction technique has been developed for the determination of pyronaridine (PND), an antimalarial drug, in human plasma. After extraction with C18 solid-phase sorbent, PND was analyzed using a reverse phase chromatographic method with fluorescence detection (at lambda(ex)=267 nm and lambda(em)=443 nm). The mean extraction recovery for PND was 95.2%. The coefficient of variation for intra-assay precision, inter-assay precision and accuracy was less than 10%. The quantification limit with fluorescence detection was 0.010 microg/mL plasma. The method described herein has several advantages over other published methods since it is easy to perform and rapid. It also permits reducing both, solvent use and sample preparation time. The method has been used successfully to assay plasma samples from clinical pharmacokinetic studies.
    Matched MeSH terms: Antimalarials/blood*; Antimalarials/isolation & purification; Antimalarials/pharmacokinetics
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