scholarly journals Plasmodium falciparum: In Vitro Cytotoxicity Testing Using MTT

1998 ◽  
Vol 3 (1) ◽  
pp. 49-53 ◽  
Author(s):  
J. Enrico Lazaro ◽  
Frederick Gay

The microculture tetrazolium assay using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was used to estimate the 50% inhibitory concentration of chloroquine, quinine, artemisinin, and atovaquone using a Plasmodium falciparum in vitro culture system. The MTT assay was compared to the standard tritiated hypoxan-thine assay and to a previously described method, the 2,2′-di-p-nitrophenyl-5,5′-diphenyl-3,3′-[3,3′-dimethoxy-4,4′-diphenylenel-ditetrazolium chloride (NBT) assay. In general, the results show that the three assays generate comparative results. The results of this study suggest that the MTT method is able to give a profile of cytotoxic dose response effects over a wide range of concentrations of a drug. The method may be used in work that does not require extreme pre-cision and sensitivity, for instance, as a portable rapid screen to assay natural products for in vitro cytotoxic ac-tivity against Plasmodium falciparum.

Author(s):  
J. Creed ◽  
T.G. McEvoy ◽  
J.J. Robinson ◽  
R.P. Aitken ◽  
R.M. Palmer ◽  
...  

Superovulatory treatments for ewes are normally preceded by a period of priming. In a recent study involving two contrasting levels of feeding (0.6 versus 2.4 x maintenance), McEvoy et al (1993) observed that the higher level of feeding suppressed pre-ovulatory plasma progesterone concentrations and the subsequent early development and viability of fertilized ova. This finding suggests that there is a need to reconsider the recommendation, based on data for spontaneously-ovulating ewes, that ‘superovulated embryo donor ewes’ should be maintained on a high level of feeding during the period of oocyte maturation. It also raises questions regarding the form of the relationship between food intake and plasma progesterone concentrations over the wide range of feeding levels that occur in practice. The aims of the present study were therefore two-fold; firstly, to investigate the relationship between level of feeding and plasma progesterone for feed intakes that ranged from 0.6 x maintenance (M) to 2.4 M and secondly to assess the effect of pre-ovulatory feeding levels on the number, quality and viability of ova produced following superovulation.


2010 ◽  
Vol 54 (3) ◽  
pp. 1200-1206 ◽  
Author(s):  
Samuel L. Nsobya ◽  
Moses Kiggundu ◽  
Sarah Nanyunja ◽  
Moses Joloba ◽  
Bryan Greenhouse ◽  
...  

ABSTRACT The control of malaria is challenged by resistance of Plasmodium falciparum to multiple drugs. New combination regimens are now advocated for the treatment of uncomplicated falciparum malaria, but the extent of resistance to newer agents is incompletely understood. We measured the in vitro sensitivity of P. falciparum parasites cultured from children enrolled in a drug efficacy trial in Kampala, Uganda, from 2006 to 2008. Sensitivities were measured by comparing levels of histidine-rich protein-2 in parasites incubated with different concentrations of drugs with those in untreated controls. The cultured parasites exhibited a wide range of sensitivities to chloroquine (CQ); monodesethylamodiaquine (MDAQ), the major active metabolite of amodiaquine; and quinine (QN). Mean 50% inhibitory concentration (IC50) results were above standard cutoffs for resistance for CQ and MDAQ. Parasites were generally sensitive to dihydroartemisinin (DHA), lumefantrine (LM), and piperaquine (PQ). For CQ, MDAQ, and QN but not the other drugs, activities against individual strains were highly correlated. We also assessed known resistance-mediating polymorphisms in two putative transporters, pfcrt and pfmdr1. When parasites that were least and most sensitive to each drug were compared, the pfmdr1 86Y mutation was significantly more common in parasites that were most resistant to CQ and MDAQ, and the pfmdr1 D1246Y mutation was significantly more common in parasites that were most resistant to MDAQ and QN. In summary, we demonstrated in parasites from Kampala a range of sensitivities to older drugs; correlation of sensitivities to CQ, MDAQ, and QN; and good activity against nearly all strains for DHA, LM, and PQ.


Author(s):  
RANA DATTA ◽  
SANKHADIP BOSE ◽  
SUDIP KUMAR MANDAL

Objective: The objective of the study was to determine the in vitro hepatic toxicity profile of methanolic extract of leaves of Pterospermum acerifolium (L.) Willd. (MEPA) using a mammalian hepatic cell line (HepG2). Methods: To assess its in vitro hepatic toxicity, 3-(4,5-dimethylthiazol-2-yl)-2,5-2,5-diphenyltetrazolium bromide assay using MEPA at a concentration of 25 μg, 50 μg, 100 μg, 200 μg, and 300 μg was carried out. Sorafenib tosylate was used as the standard agent to assess cytotoxicity. Results: The inhibitory concentration 50 (IC50) value for HepG2 cell lines was determined after 24 h. Thereafter the cytotoxicity study was again performed with the ½ IC50, IC50, and 2IC50 doses of MEPA. Experimentally, the IC50 was found to be 150.42 μg/ml for HepG2 using MEPA. A dose-dependent cytotoxicity and reduction in optical density were also observed with incremental MEPA administration. Conclusion: The cytotoxic potential of MEPA was found to be much less than that of sorafenib tosylate. Thus, MEPA shows in vitro cytotoxicity in mammalian hepatic cells (HepG2) at a concentration as low as 100 μg.


2013 ◽  
Vol 57 (4) ◽  
pp. 1723-1729 ◽  
Author(s):  
Mingming Hao ◽  
Dandan Jia ◽  
Qing Li ◽  
Yongshu He ◽  
Lili Yuan ◽  
...  

ABSTRACTThe recent reports of resistance inPlasmodium falciparumto artemisinin derivatives and their partner drugs demand intensive studies toward understanding the molecular mechanisms of resistance. In this study, we examined thein vitrosusceptibility of 63P. falciparumfield isolates collected from the China-Myanmar border area to chloroquine (CQ) and piperaquine (PPQ). Parasite isolates remained highly resistant to CQ, with the geometric mean 50% inhibitory concentration (IC50) of 252.7 nM and a range of 51.9 to 1,052.0 nM. In comparison, these parasites had a geometric mean IC50of 28.4 nM for PPQ, with a fairly wide range of 5.3 to 132.0 nM, suggesting that certain parasite isolates displayed relatively high levels of resistance to PPQ. Interestingly, within the 4 years of study, the parasites exhibited a continuous decline in susceptibilities to both CQ and PPQ, and there was a significant correlation between responses to CQ and PPQ (Pearson correlation coefficient = 0.79,P< 0.0001). Consistent with the CQ-resistant phenotype, all parasites carried thepfcrtK76T mutation, and most parasites had the CVIET type that is prevalent in Southeast Asia. In contrast,pfmdr1mutations were relatively rare, and no gene amplification was detected. Only thepfmdr1N1042D mutation was associated with resistance to CQ. For thepfmrp1gene, four substitutions reached relatively high prevalence of >22%, and the I876V mutation was associated with reduced sensitivity to CQ. However, we could not establish a link between PPQ responses and the polymorphisms in the three genes associated with quinoline drug resistance.


Author(s):  
Jhons Fatriyadi Suwandi ◽  
Mahardika Agus Wijayanti ◽  
Mustofa .

Objective: The aim of this study was to assess the antiplasmodial and cytotoxic activities and to evaluate the selectivity indices of acetone, ethanol and aqueous extracts of Peronema canescens leaves.Methods: Antiplasmodial activity was measured in vitro against Plasmodium falciparum strains D10 and FCR3 by 72 h incubation at 37 °C in a candle jar. Parasitaemia was calculated by counting the parasite numbers in thin smears. In vitro cytotoxicity was assayed in Vero cells using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and reading the absorbency at 595 nm with an ELISA reader. The assessed parameters included: 50% inhibitory concentration (IC50) of antiplasmodial activity, IC50 of cytotoxic activity and the selectivity index of the Peronema canescens leaf extract.Results: The IC50 values for the acetone, ethanol and aqueous extracts were 26.33±1.65, 37.96±8.17 and 12.26±1.05 μg/ml, respectively, against the Plasmodium falciparum D10 strain and 51.14±8.65, 70.22±14.13 and 34.85±6.04 μg/ml, respectively, against the FCR3 strain. For Vero cells, the IC50 values for the acetone, ethanol and aqueous extracts were 23.37±5.63, 629.46±24.85 and 634.00±144.82 μg/ml, respectively. The selectivity indices of these extracts were 0.89, 16.46 and 51.70, respectively, for the D10 strain and 0.46, 8.90 and 18.00, respectively, for the FCR3 strain.Conclusion: The aqueous extract of Peronema canescens leaves had the highest in vitro antiplasmodial activity and the best selectivity index.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sospeter N. Njeru ◽  
Jackson M. Muema

Abstract Objectives We and others have shown that Aspilia pluriseta is associated with various biological activities. However, there is a lack of information on its cytotoxicity. This has created an information gap about the safety of A. pluriseta extracts. As an extension to our recent publication on the antimicrobial activity and the phytochemical characterization of A. pluriseta root extracts, here we report on cytotoxicity of tested solvent fractions. We evaluated the potential cytotoxicity of these root extract fractions on Vero cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Results We show that all solvent extract fractions (except methanolic solvent fractions) had cytotoxic concentration values that killed 50% of the Vero cells (CC50) greater than 20 µg/mL and selectivity index (SI) greater than 1.0. Taken together, we demonstrate that, A. pluriseta extract fractions’ earlier reported bioactivities are within the acceptable cytotoxicity and selective index limits. This finding scientifically validates the potential use of A. pluriseta in the discovery of safe therapeutics agents.


2006 ◽  
Vol 50 (10) ◽  
pp. 3343-3349 ◽  
Author(s):  
Halima Kaddouri ◽  
Serge Nakache ◽  
Sandrine Houzé ◽  
France Mentré ◽  
Jacques Le Bras

ABSTRACT The extension of drug resistance among malaria-causing Plasmodium falciparum parasites in Africa necessitates implementation of new combined therapeutic strategies. Drug susceptibility phenotyping requires precise measurements. Until recently, schizont maturation and isotopic in vitro assays were the only methods available, but their use was limited by technical constraints. This explains the revived interest in the development of replacement methods, such as the Plasmodium lactate dehydrogenase (pLDH) immunodetection assay. We evaluated a commercially controlled pLDH enzyme-linked immunosorbent assay (ELISA; the ELISA-Malaria antigen test; DiaMed AG, Cressier s/Morat, Switzerland) to assess drug susceptibility in a standard in vitro assay using fairly basic laboratory equipment to study the in vitro resistance of malaria parasites to major antimalarials. Five Plasmodium falciparum clones and 121 clinical African isolates collected during 2003 and 2004 were studied by the pLDH ELISA and the [8-3H]hypoxanthine isotopic assay as a reference with four antimalarials. Nonlinear regression with a maximum effect model was used to estimate the 50% inhibitory concentration (IC50) and its confidence intervals. The two methods were observed to have similar reproducibilities, but the pLDH ELISA demonstrated a higher sensitivity. The high correlation (r = 0.98) and the high phenotypic agreement (κ = 0.88) between the two methods allowed comparison by determination of the IC50s. Recently collected Plasmodium falciparum African isolates were tested by pLDH ELISA and showed drug resistance or decreased susceptibilities of 62% to chloroquine and 11.5% to the active metabolite of amodiaquine. No decreased susceptibility to lumefantrine or the active metabolite of artemisinin was detected. The availability of this simple and highly sensitive pLDH immunodetection assay will provide an easier method for drug susceptibility testing of malaria parasites.


2014 ◽  
Vol 29 (4) ◽  
pp. 457-469 ◽  
Author(s):  
Federica Riva ◽  
Claudia Omes ◽  
Roberto Bassani ◽  
Rossella E Nappi ◽  
Giuliano Mazzini ◽  
...  

2011 ◽  
Vol 40 (1) ◽  
pp. 124-128
Author(s):  
Sabine Wohlres-Viana ◽  
Mariana Cortes Boite ◽  
João Henrique Moreira Viana ◽  
Marco Antonio Machado ◽  
Luiz Sérgio de Almeida Camargo

The objectives of this work were to identify and to evaluate possible differences on gene expression of aquaporins and Na/K-ATPases transcripts between embryos in vivo and in vitro produced. For each group, 15 blastocysts distributed in three pools were used for RNA extraction followed by amplification and reverse transcription. The resulting cDNAs were submitted to Real-Time PCR, using the GAPDH gene as endogenous control. It was not possible to identify AQP1 transcripts. Relative expression of AQP3 (1.33 ± 0.78) and AQP11 (2.00 ± 1.42) were not different in blastocysts in vitro and in vivo produced. Na/K-ATPase α1 gene (2.25 ± 1.07) was overregulated whereas Na/K-ATPase β2 transcripts 0.40 ± 0.30) did not differ among blastocysts produced in vitro from those produced in vivo. Transcripts for gene AQP1 are not present in bovine blastocysts. In vitro culture system does not alter expression of genes AQP3, AQP11 and Na/K-ATPase β2 genes, however, it affects expression of Na/K-ATPase α1.


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