Displaying publications 1 - 20 of 42 in total

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  1. Balakrishnan DD, Kumar SG
    Parasit Vectors, 2014;7:219.
    PMID: 24886677 DOI: 10.1186/1756-3305-7-219
    Biochemical evidence of a caspase-like execution pathway has been demonstrated in a variety of protozoan parasites, including Blastocystis spp. The distinct differences in the phenotypic characterization reported previously have prompted us to compare the rate of apoptosis in Blastocystis spp. isolated from individuals who were symptomatic and asymptomatic. In the current study, we analysed the caspase activation involved in PCD mediated by a cytotoxic drug, (metronidazole) in both symptomatic & asymptomatic isolates.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  2. Afzan MY, Sivanandam S, Suresh K
    J Appl Microbiol, 2012 Jan;112(1):132-7.
    PMID: 22040369 DOI: 10.1111/j.1365-2672.2011.05185.x
    We previously reported that Modified Field Stain (MF) can be used as a rapid stain for diagnosis. In the present study we extend the observation to include the stain as an alternative method to assess viability of the cells.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology
  3. Girish S, Kumar S, Aminudin N
    Parasit Vectors, 2015;8:332.
    PMID: 26082155 DOI: 10.1186/s13071-015-0942-y
    In the local Malaysian context, herbal plants such as Eurycoma longifolia (Tongkat Ali), Orthosiphon stamineus (MisaiKucing), Ficus deltoidea (Mas Cotek), Zingiber officinale (Halia Bara) and Barringtonia racemosa (Putat) are known and widely used for its therapeutic properties. The first part of this study aims to screen for the anti-protozoal activity of these herbal plant extracts against Blastocystis sp. isolate subtype (ST) 3. Herbal extract with the highest efficacy was further fractionized into water and ethyl acetate fractions and tested against ST1, ST3 and ST5 Blastocystis sp. isolates. These isolates were also exposed to allopathic drugs, Metronidazole (MTZ), Tinidazole, Trimethoprim-sulfamethoxazole(TMP-SMX), Ketoconazole and Nitazoxanide for comparison purpose.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  4. Taha M, Sain AA, Ali M, Anouar EH, Rahim F, Ismail NH, et al.
    Bioorg Chem, 2020 06;99:103819.
    PMID: 32325334 DOI: 10.1016/j.bioorg.2020.103819
    Leishmaniasis has affected a wider part of population around the globe. Most often, the existing regiments to battle against leishmaniasis are inadequate and limited. In our ongoing efforts to develop new leishmanicidal agents, we have synthesized a series of novel and symmetrical bis-Schiff base-disulfide hybrids 1-27. Intermediate disulfide was synthesized from corresponding 2-aminothiol followed by reacting the coupled adduct with various aromatic aldehydes. All these compounds showed outstanding inhibition when compared with standard (Table 1). Out of twenty seven analogues, twenty two analogues i.e. 1-5, 7-13, 17-21, 23-27 analogues showed excellent inhibitory potential with EC50 values ranging from 0.010 ± 0.00 to 0.096 ± 0.01 μM while five compounds i.e. 6, 14-16, and 22 showed good inhibitory potential with EC50 values ranging from 0.10 ± 0.00 to 0.137 ± 0.01 μM when compared with the standard Amphotericin B. Structure-activity relationship has been established while molecular docking studies were performed to pin the binding interaction of active molecules. This study will help to develop new antileishmanial lead compounds.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  5. Lasing T, Phumee A, Siriyasatien P, Chitchak K, Vanalabhpatana P, Mak KK, et al.
    Bioorg Med Chem, 2020 01 01;28(1):115187.
    PMID: 31761725 DOI: 10.1016/j.bmc.2019.115187
    In a search for potent antileishmanial drug candidates, eighteen rhodacyanine analogues bearing fluorine or perfluoroalkyl substituents at various positions were synthesized. These compounds were tested for their inhibitory activities against Leishmania martiniquensis and L. orientalis. This 'fluorine-walk' analysis revealed that the introduction of fluorine atom at C-5, 6, 5', or 6' on the benzothiazole units led to significant enhancement of the activity, correlating with the less negative reduction potentials of the fluorinated analogues confirmed by the electrochemical study. On the other hand, CF3 and OCF3 groups were found to have detrimental effects, which agreed with the poor aqueous solubility predicted by the in silico ADMET analysis. In addition, some of the analogues including the difluorinated species showed exceptional potency against the promastigote and axenic amastigote stages (IC50 = 40-85 nM), with the activities surpassing both amphotericin B and miltefosine.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  6. 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: Antiprotozoal Agents/pharmacology
  7. Rajendran K, Anwar A, Khan NA, Shah MR, Siddiqui R
    ACS Chem Neurosci, 2019 06 19;10(6):2692-2696.
    PMID: 30970208 DOI: 10.1021/acschemneuro.9b00111
    Primary amoebic meningoencephalitis (PAM), a deadly brain infection, is caused by brain-eating amoeba Naegleria fowleri. The current first line of treatment against PAM is a mixture of amphotericin B, rifampin, and miltefosine. Since, no single effective drug has been developed so far, the mortality rate is above 95%. Moreover, severe adverse side effects are associated with these drugs. Nanotechnology has provided several advances in biomedical applications especially in drug delivery and diagnosis. Herein, for the first time we report antiamoebic properties of cinnamic acid (CA) and gold nanoparticles conjugated with CA (CA-AuNPs) against N. fowleri. CA-AuNPs were successfully synthesized by sodium borohydride reduction of tetrachloroauric acid. Size and morphology were determined by atomic force microscopy (AFM) while the surface plasmon resonance band was analyzed by ultraviolet-visible (UV-vis) spectrophotometry for the characterization of the nanoparticles. Amoebicidal and cytopathogenicity (host cell cytotoxicity) assays revealed that both CA and CA-AuNPs displayed significant anti- N. fowleri properties ( P < 0.05), whereas nanoparticles conjugation further enhanced the anti- N. fowleri effects of CA. This study established a potential drug lead, while CA-AuNPs appear to be promising candidate for drug discovery against PAM.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  8. Kumarasamy V, Anbazhagan D, Subramaniyan V, Vellasamy S
    Curr Pharm Des, 2018;24(27):3172-3175.
    PMID: 30084327 DOI: 10.2174/1381612824666180807101536
    Blastocystis sp. is a unicellular parasitic microorganism commonly found in the gastrointestinal tracts of humans and animals. It causes symptomatic or asymptomatic infection and its route of transmission is via fecal-oral. High prevalence of Blastocystis infection in developing countries is usually due to poor hygiene practices, exposure to animals infected with the parasite and intake of contaminated water or food. Blastocystis infected individuals often suffer from diarrhea, abdominal pain, nausea, and stomach bloating. Even though pathogenicity of Blastocystis is unclear, it is commonly associated with irritable bowel syndrome. In this review, we have analysed the evidence that shows the association between this microorganism and gastrointestinal disorders. There have been a number of studies which showed that the pathogenicity of Blastocystis is related to its different STs. The pathogenicity is speculated to be due to cysteine proteases formation which stimulates mucosal cells to release interleukin-8 which has been associated with extreme dehydration and gut inflammation. In vitro studies on human colonic epithelial cells revealed that incubation of Blastocystis modulated the host immune response by stimulating the formation of pro-inflammatory cytokines and granulocyte macrophage colonystimulating factor. Metronidazole is found to be the first-line drug of choice. Another treatment option is the combination therapy with trimethoprim/sulfamethoxazole.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  9. Salin NH, Noordin R, Al-Najjar BO, Kamarulzaman EE, Yunus MH, Karim IZA, et al.
    PLoS One, 2020;15(5):e0225232.
    PMID: 32442170 DOI: 10.1371/journal.pone.0225232
    Toxoplasma gondii is the etiologic agent of toxoplasmosis, a disease which can lead to morbidity and mortality of the fetus and immunocompromised individuals. Due to the limited effectiveness or side effects of existing drugs, the search for better drug candidates is still ongoing. In this study, we performed structure-based screening of potential dual-targets inhibitors of active sites of T. gondii drug targets such as uracil phosphoribosyltransferase (UPRTase) and adenosine kinase (AK). First screening of virtual compounds from the National Cancer Institute (NCI) was performed via molecular docking. Subsequently, the hit compounds were tested in-vitro for anti- T. gondii effect using cell viability assay with Vero cells as host to determine cytotoxicity effects and drug selectivities. Clindamycin, as positive control, showed a selectivity index (SI) of 10.9, thus compounds with SI > 10.9 specifically target T. gondii proliferation with no significant effect on the host cells. Good anti- T. gondii effects were observed with NSC77468 (7-ethoxy-4-methyl-6,7-dihydro-5H-thiopyrano[2,3-d]pyrimidin-2-amine) which showed SI values of 25. This study showed that in-silico selection can serve as an effective way to discover potentially potent and selective compounds against T. gondii.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  10. He WH, Feng XX, Wu X, Zhai XH, Li YY, Zhang B, et al.
    Trop Biomed, 2020 Dec 01;37(4):871-876.
    PMID: 33612740 DOI: 10.47665/tb.37.4.871
    To evaluate the inhibitory effects of drugs on the growth of Babesia gibsoni, relative quantification real-time PCR method was developed in this study. The 18S rRNA gene was used as a target gene for the 2-ΔΔCt method analysis. Additionally, chicken RNA was added to the parasitized blood before total RNA extraction. The chicken β-actin gene was selected as an internal control gene for the 2-ΔΔCt method analysis. The 100 µL parasitized blood samples with different percentages of parasitized erythrocytes (PPEs) (3%, 1.5%, 0.75%, 0.375% and 0.1875%) were prepared for relative quantification of B. gibsoni. Regression analysis results revealed significant linear relationships between the relative quantification value and parasitemia. 18S rRNA gene expression was significantly decreased after treatment with diminazene aceturate and artesunate in vitro drug sensitivity test. This result suggested that this relative quantification real-time PCR method can be used to evaluate the effects of drug inhibition.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  11. Dhurga DB, Suresh K, Tan TC
    PLoS One, 2016;11(7):e0155390.
    PMID: 27471855 DOI: 10.1371/journal.pone.0155390
    The role and function of the granular life cycle stage in Blastocystis sp, remains uncertain despite suggestions being made that the granules are metabolic, reproductive and lipid in nature. This present study aims to understand granular formation by triggering apoptosis in Blastocystis sp. by treating them with metronidazole (MTZ). Blastocystis sp.cultures of 4 sub-types namely 1, 2, 3 and 5 when treated with 0.01 and 0.0001 mg/ml of metronidazole (MTZ) respectively showed many of the parasites to be both viable and apoptotic (VA). Treated subtype 3 isolates exhibited the highest number of granular forms i.e. 88% (p<0.001) (0.0001 mg/ml) and 69% (p<0.01) (0.01 mg/ml) respectively at the 72 h in in vitro culture compared to other subtypes. These VA forms showed distinct granules using acridine orange (AO) and 4',6-diamino-2-phenylindole (DAPI) staining with a mean per cell ranging from 5 in ST 5 to as high as 16 in ST 3. These forms showed intact mitochondria in both viable apoptotic (VA) and viable non-apoptotic (VNA) cells with a pattern of accumulation of lipid droplets corresponding to viable cells. Granular VA forms looked ultra-structurally different with prominent presence of mitochondria-like organelle (MLO) and a changed mitochondrial trans-membrane potential with thicker membrane and a highly convoluted inner membrane than the less dense non-viable apoptotic (NVA) cells. This suggests that granular formation during apoptosis is a self-regulatory mechanism to produce higher number of viable cells in response to treatment. This study directs the need to search novel chemotherapeutic approaches by incorporating these findings when developing drugs against the emerging Blastocystis sp. infections.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  12. Thu HE, Hussain Z, Mohamed IN, Shuid AN
    Curr Drug Targets, 2018;19(14):1657-1671.
    PMID: 29468964 DOI: 10.2174/1389450119666180219123815
    BACKGROUND: Eurycoma longifolia (E. longifolia) has gained widespread recognition due to its versatile pharmacological activities including aphrodisiac, anticancer, antimicrobial, antioxidant, anti-inflammatory, anxiolytic, anti-diabetic, ergogenic, insecticidal, anti-rheumatism, bone protection, and anti-ulcer effects.

    OBJECTIVE: This review was aimed to critically overview the literature and summarizes the antibacterial, antiprotozoal, and antifungal trends of E. longifolia and its medicinally active components.

    RESULTS: Besides its well-documented safety, efficacy, and tolerability, a plethora of in vitro, in vivo, and human clinical studies has evidenced the antimicrobial efficacy of E. longifolia and its bioactive constituents. Phytochemical screening of various types of extracts (methanolic, ethyl acetate, and nbutanolic) from different parts (roots, stem, and leaves) of E. longifolia displayed a dose-dependent antibacterial, antiprotozoal, and antifungal responses. Comparative analysis revealed that the root extract of E. longifolia exhibited the highest antimicrobial efficacy compared to other parts of the plant. Bioactivity-guided fractionation identified that among all of the medicinal compounds isolated/ extracted from different parts of E. longifolia, eurycomanone displayed the strongest antibacterial, antiprotozoal and antifungal activities.

    CONCLUSION: Based on the critical analysis of the literature, we identified that E. longifolia exhibits promising antibacterial, antiprotozoal, and antifungal efficacies against various pathogenic microbes and thus can be considered as a potential complementary and alternative antimicrobial therapy.

    Matched MeSH terms: Antiprotozoal Agents/pharmacology
  13. Anwar A, Khan NA, Siddiqui R
    Parasit Vectors, 2018 01 09;11(1):26.
    PMID: 29316961 DOI: 10.1186/s13071-017-2572-z
    Acanthamoeba spp. are protist pathogens and causative agents of serious infections including keratitis and granulomatous amoebic encephalitis. Its ability to convert into dormant and highly resistant cysts form limits effectiveness of available therapeutic agents and presents a pivotal challenge for drug development. During the cyst stage, Acanthamoeba is protected by the presence of hardy cyst walls, comprised primarily of carbohydrates and cyst-specific proteins, hence synthesis inhibition and/or degradation of cyst walls is of major interest. This review focuses on targeting of Acanthamoeba cysts by identifying viable therapeutic targets.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  14. Taha M, Ismail NH, Jamil W, Rashwan H, Kashif SM, Sain AA, et al.
    Eur J Med Chem, 2014 Sep 12;84:731-8.
    PMID: 25069019 DOI: 10.1016/j.ejmech.2014.07.078
    4-Methylbenzimidazole 1-28 novel derivatives were synthesized and evaluated for their antiglycation and antioxidant activities. Compounds 1-7 and 11 showed excellent activities ranged 140-280 μM, better than standard drug rutin (294.46 ± 1.50 μM). Compound 1-28 were also evaluated for DPPH activities. Compounds 1-8 showed excellent activities, ranging 12-29 μM, better than standard drug n-propylgallate (IC50 = 30.30 ± 0.40 μM). For superoxide anion scavenging activity, compounds 1-7 showed better activity than standard n-propylgallate (IC50 = 106.34 ± 1.6 μM), ranged 82-104 μM. These compounds were found to be nontoxic to THP-1 cells.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  15. Ibrahim MA, Yusof MS, Amin NM
    Molecules, 2014 Apr 22;19(4):5191-204.
    PMID: 24759076 DOI: 10.3390/molecules19045191
    Thiourea derivatives display a broad spectrum of applications in chemistry, various industries, medicines and various other fields. Recently, different thiourea derivatives have been synthesized and explored for their anti-microbial properties. In this study, four carbonyl thiourea derivatives were synthesized and characterized, and then further tested for their anti-amoebic properties on two potential pathogenic species of Acanthamoeba, namely A. castellanii (CCAP 1501/2A) and A. polyphaga (CCAP 1501/3A). The results indicate that these newly-synthesized thiourea derivatives are active against both Acanthamoeba species. The IC50 values obtained were in the range of 2.39-8.77 µg·mL⁻¹ (9.47-30.46 µM) for A. castellanii and 3.74-9.30 µg·mL⁻¹ (14.84-31.91 µM) for A. polyphaga. Observations on the amoeba morphology indicated that the compounds caused the reduction of the amoeba size, shortening of their acanthopodia structures, and gave no distinct vacuolar and nuclear structures in the amoeba cells. Meanwhile, fluorescence microscopic observation using acridine orange and propidium iodide (AOPI) staining revealed that the synthesized compounds induced compromised-membrane in the amoeba cells. The results of this study proved that these new carbonyl thiourea derivatives, especially compounds M1 and M2 provide potent cytotoxic properties toward pathogenic Acanthamoeba to suggest that they can be developed as new anti-amoebic agents for the treatment of Acanthamoeba keratitis.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  16. Kavitha N, Noordin R, Kit-Lam C, Sasidharan S
    Molecules, 2012 Aug 02;17(8):9207-19.
    PMID: 22858841 DOI: 10.3390/molecules17089207
    The inhibitory effect of active fractions of Eurycoma longifolia (E. longifolia) root, namely TAF355 and TAF401, were evaluated against Toxoplasma gondii (T. gondii). In our previous study, we demonstrated that T. gondii was susceptible to TAF355 and TAF401 with IC₅₀ values of 1.125 µg/mL and 1.375 µg/mL, respectively. Transmission (TEM) and scanning electron microscopy (SEM) observations were used to study the in situ antiparasitic activity at the IC₅₀ value. Clindamycin was used as positive control. SEM examination revealed cell wall alterations with formation of invaginations followed by completely collapsed cells compared to the normal T. gondii cells in response to the fractions. The main abnormality noted via TEM study was decreased cytoplasmic volume, leaving a state of structural disorganization within the cell cytoplasm and destruction of its organelles as early as 12 h of treatment, which indicated of rapid antiparasitic activity of the E. longifolia fractions. The significant antiparasitic activity shown by the TAF355 and TAF401 active fractions of E. longifolia suggests their potential as new anti-T. gondii agent candidates.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  17. Nakisah MA, Ida Muryany MY, Fatimah H, Nor Fadilah R, Zalilawati MR, Khamsah S, et al.
    World J Microbiol Biotechnol, 2012 Mar;28(3):1237-44.
    PMID: 22805843 DOI: 10.1007/s11274-011-0927-8
    Crude methanol extracts of a marine sponge, Aaptos aaptos, collected from three different localities namely Kapas, Perhentian and Redang Islands, Terengganu, Malaysia, were tested in vitro on a pathogenic Acanthamoeba castellanii (IMR isolate) to examine their anti-amoebic potential. The examination of anti-Acanthamoebic activity of the extracts was conducted in 24 well plates for 72 h at 30 °C. All extracts possessed anti-amoebic activity with their IC(50) values ranging from 0.615 to 0.876 mg/mL. The effect of the methanol extracts on the surface morphology of A. castellanii was analysed under scanning electron microscopy. The ability of the extracts to disrupt the amoeba cell membrane was indicated by extensive cell's blebbing, changes in the surface morphology, reduced in cell size and with cystic appearance of extract-treated Acanthamoeba. Number of acanthapodia and food cup was also reduced in this Acanthamoeba. Morphological criteria of apoptosis in Acanthamoeba following treatment with the sponge's extracts was determined by acridine orange-propidium iodide staining and observed by fluorescence microscopy. By this technique, apoptotic and necrotic cells can be visualized and quantified. The genotoxic potential of the methanol extracts was performed by the alkaline comet assay. All methanol extracts used were significantly induced DNA damage compared to untreated Acanthamoeba by having high percentage of scores 1, 2, and 3 of the DNA damage. Results from cytotoxicity and genotoxicity studies carried out in the present study suggest that all methanol extracts of A. aaptos have anti-amoebic properties against A. castellanii.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  18. Kavitha N, Noordin R, Chan KL, Sasidharan S
    PMID: 22781137 DOI: 10.1186/1472-6882-12-91
    Toxoplasma gondii infection causes toxoplasmosis, an infectious disease with worldwide prevalence. The limited efficiency of drugs against this infection, their side effects and the potential appearance of resistant strains make the search of novel drugs an essential need. We examined Eurycoma longifolia root extract and fractions as potential sources of new compounds with high activity and low toxicity. The main goal of this study was to investigate the anti-T. gondii activity of crude extract (TACME) and four fractions (TAF 273, TAF 355, TAF 191 and TAF 401) from E. longifolia, with clindamycin as the positive control.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  19. Dhurga DB, Suresh KG, Tan TC, Chandramathi S
    Trans R Soc Trop Med Hyg, 2012 Dec;106(12):725-30.
    PMID: 23141370 DOI: 10.1016/j.trstmh.2012.08.005
    Previous studies have shown that apoptosis-like features are observed in Blastocystis spp., an intestinal protozoan parasite, when exposed to the cytotoxic drug metronidazole (MTZ). This study reports that among the four subtypes of Blastocystis spp. investigated for rate of apoptosis when treated with MTZ, subtype 3 showed the highest significant increase after 72h of in vitro culture when treated with MTZ at 0.1mg/ml (79%; p<0.01) and 0.0001mg/ml (89%; p<0.001). The close correlation between viable cells and apoptotic cells for both dosages implies that the pathogenic potential of these isolates has been enhanced when treated with MTZ. This suggests that there is a mechanism in Blastocystis spp. that actually regulates the apoptotic process to produce higher number of viable cells when treated. Apoptosis may not just be programmed cell death but instead a mechanism to increase the number of viable cells to ensure survival during stressed conditions. The findings of the present study have an important contribution to influence chemotherapeutic approaches when developing drugs against the emerging Blastocystis spp. infections.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology*
  20. Imran S, Taha M, Ismail NH
    Curr Med Chem, 2015;22(38):4412-33.
    PMID: 26438249
    Bisindolylmethane and its derivatives are pharmacologically active and applicable in the field of pharmaceutical chemistry. Bisindolylmethanes have a variety of biological activities such as antihyperglycemic, antiinflammatory, antibacterial, anticancer, and antileishmanial activities, including enzyme inhibition activity. They play a crucial role in many diseases especially anticancer activity. Modifying their structure had proven to be useful in the search of new therapeutic agents. Extensive research carried out on bisindolylmethane and its derivatives shows that they are pharmacologically significant. The present review focuses on the pharmacological profile of bisindolylmethane derivatives. This review includes the current literature with an update of research findings as well as the perspectives that they hold for future research.
    Matched MeSH terms: Antiprotozoal Agents/pharmacology
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