In vitro effect of the antimalarial drug proguanil hydrochloride on viability and DNA damage in human peripheral blood lymphocytes

Gajski, Goran; Dinter, Domagoj; Garaj‐Vrhovac, Vera

doi:10.1016/j.etap.2010.07.001

Cited by 6 publications

(6 citation statements)

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“…Samples with S9 metabolic activation also did not show any significant difference in percentage of viable cells, which was expected as no active metabolite of ATO has been identified so far [50,51]. Given that a greater part of DNA-damaging effect was induced after S9 metabolic activation, it is to presume that principal metabolite CYC has the greatest impact on DNA molecule [23]. Based on these results, we concluded that ATO at the tested concentrations is not cyto/genotoxic [24].…”

Section: Discussionsupporting

confidence: 52%

“…These results lead us to the conclusion that PROG and its metabolites have an impact on cell viability and DNA integrity. Given that a greater part of DNA-damaging effect was induced after S9 metabolic activation, it is to presume that principal metabolite CYC has the greatest impact on DNA molecule [23].…”

Section: Discussionmentioning

confidence: 99%

“…Both ATO and PROG have a favourable side effect profile [21,22], and although they have not been often associated with severe adverse reactions in the recommended dosages, to the best of our knowledge, cyto/ genotoxicity studies have not been performed with ATO in combination with PROG in vitro. Previously, we reported that PROG alone in clinically relevant concentrations has an impact on cytotoxicity and DNA integrity of human peripheral blood lymphocytes (HPBLs) in vitro [23]. On the contrary, ATO alone did not have any impact on cell viability and DNA damage in clinically relevant concentrations in HPBLs in vitro [24].…”

Section: Introductionmentioning

confidence: 91%

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Cytogenetic and oxidative status of human lymphocytes after exposure to clinically relevant concentrations of antimalarial drugs atovaquone and proguanil hydrochloride in vitro

Dinter

Gajski

Domijan

et al. 2015

Fundamemntal Clinical Pharma

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Atovaquone (ATO) and proguanil hydrochloride (PROG) is the fixed combination for the prevention and treatment of Plasmodium falciparum malaria. As safe and effective antimalarial drugs are needed in both the treatment and the prophylaxis of malaria, this study was performed to investigate their possible cyto/genotoxic potential towards human lymphocytes and the possible mechanism responsible for it. Two different concentrations of ATO and PROG were used with and without S9 metabolic activation. The concentrations used were those found in human plasma when a fixed-dose combination of ATO and PROG was used: 2950/130 ng/mL after prophylactic treatment and 11 800/520 ng/mL after treatment of malaria, respectively. Possible cellular and DNA-damaging effects were evaluated by cell viability and alkaline comet assays, while oxidative stress potential was evaluated by formamidopyrimidine-DNA glycosylase (Fpg)-modified comet assay, in addition to measuring malondialdehyde and glutathione levels. According to our results, the ATO/PROG combination displayed only weak cyto/genotoxic potential towards human lymphocytes with no impact on oxidative stress parameters, suggesting that oxidative stress is not implicated in their mechanism of action towards human lymphocytes. Given that the key portion of the damaging effects was induced after S9 metabolic activation, it is to presume that the principal metabolite of PROG, cycloguanil, had the greatest impact. The obtained results indicate that the ATO/PROG combination is relatively safe for the consumption from the aspect of cyto/genotoxicity, especially if used for prophylactic treatment. Nevertheless, further cytogenetic research and regular patient monitoring are needed to minimize the risk of adverse events especially among frequent travellers.

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Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 91%

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Cytogenetic and oxidative status of human lymphocytes after exposure to clinically relevant concentrations of antimalarial drugs atovaquone and proguanil hydrochloride in vitro

Dinter

Gajski

Domijan

et al. 2015

Fundamemntal Clinical Pharma

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“…In the present study, assessment of possible cytotoxic and genotoxic potential of atovaquone was made by determination of lymphocytes viability and by virtue of measuring the DNA migration of treated cells in vitro by the use of the alkaline comet assay. These techniques, especially comet assay, are relatively fast, simple and sensitive for the assessment of citotoxicity and genotoxicity in human cells after exposure to different physical and chemical agents including drugs, both in vivo and in vitro (Collins et al , ; Dusinska and Collins, ; Gajski et al ., ; Garaj‐Vrhovac and Oreščanin, ; McArt et al ., ; Piperakis, ; Tice et al ., ). Hence, the in vitro comet assay is proposed as an alternative to standard cytogenetic assays in early genotoxicity screening of drug candidates (Snyder and Green, ; Witte et al ., ).…”

Section: Discussionmentioning

confidence: 99%

An alkaline comet assay study on the antimalarial drug atovaquone in human peripheral blood lymphocytes: a study based on clinically relevant concentrations

Dinter

Gajski

Garaj‐Vrhovac

2011

J of Applied Toxicology

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Atovaquone, a hydroxynaphthoquinone, is an anti-parasite drug, selectively targeting the mitochondrial respiratory chain of malaria parasite. It is used for both the treatment and prevention of malaria, usually in a fixed combination with proguanil. Although atovaquone has not often been associated with severe adverse reactions in the recommended dosages and has a relatively favorable side effect profile, the present study was undertaken to evaluate its cytogenotoxic potential towards human peripheral blood lymphocytes. Two different concentrations of atovaquone found in plasma when used in fixed-dose combination with proguanile hydrochloride were used with and without S9 metabolic activation: 2950 ng ml(-1) used for prophylactic treatment and 11 800 ng ml(-1) used in treatment of malaria. The results showed that lymphocyte viability was not affected after the treatment, suggesting that atovaquone was not cytotoxic in the given concentrations. With the alkaline comet assay we demonstrated that in human peripheral blood lymphocytes no significant changes in comet parameters occurred after the treatment. There were no differences in tested parameters with the addition of S9 metabolic activation, indicating that atovaquone either has no metabolite or it is not toxic in the given concentrations. Since no effects were observed after the treatment, it is to be concluded that atovaquone is safe from the aspect of genototoxicity in the recommended dosages.

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“…In mammalian cells, depletion of glutathione by BSO or other chemicals leads to DNA damage and prevents DNA repair, while the addition of glutathione or glutathione precursor results in a rescue of DNA repair (42)(43)(44). While antifolates directly inhibit folate and hence DNA biosynthesis and induce chromosome damage in vitro (45), GSH has been shown to play a positive role in cell proliferation, chromosome structure formation, and nuclear protein function (46)(47)(48)(49)(50). Depletion of GSH in P. berghei ANKA may make the parasites more susceptible to DNA damage and hence more sensitive to the effects of antifolates.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Glutathione Biosynthesis Sensitizes Plasmodium berghei to Antifolates

Songsungthong

Koonyosying

Uthaipibull

et al. 2016

Antimicrob Agents Chemother

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Glutathione plays a central role in maintaining cellular redox homeostasis, and modulations to this status may affect malaria parasite sensitivity to certain types of antimalarials. In this study, we demonstrate that inhibition of glutathione biosynthesis in the Plasmodium berghei ANKA strain through disruption of the ␥-glutamylcysteine synthetase (␥-GCS) gene, which encodes the first and rate-limiting enzyme in the glutathione biosynthetic pathway, significantly sensitizes parasites in vivo to pyrimethamine and sulfadoxine, but not to chloroquine, artesunate, or primaquine, compared with control parasites containing the same pyrimethamine-resistant marker cassette. Treatment of mice infected with an antifolate-resistant P. berghei control line with a ␥-GCS inhibitor, buthionine sulfoximine, could partially abrogate pyrimethamine and sulfadoxine resistance. The role of glutathione in modulating the malaria parasite's response to antifolates suggests that development of specific inhibitors against Plasmodium ␥-GCS may offer a new approach to counter Plasmodium antifolate resistance. Malaria causes approximately 438,000 deaths from 214 million cases annually (1). As no effective vaccine is yet available, chemotherapy is relied upon to combat the disease. However, Plasmodium falciparum has become resistant to all front-line antimalarial drugs in current use, such as chloroquine (2), combination sulfadoxine-pyrimethamine (Fansidar) (3, 4) and, most worrying, artemisinin and its analogs (5-9). Thus, new strategies are needed to counter drug resistance in Plasmodium.Among the various metabolic pathways in Plasmodium, antioxidant systems are likely to be involved in drug sensitivity as they maintain redox homeostasis and counter oxidant stress triggered by antimalarials (10, 11). Glutathione (GSH) is a major antioxidant in Plasmodium (12, 13). De novo GSH biosynthesis consists of two steps: (i) production of ␥-glutamylcysteine (␥-GC) from glutamic acid and cysteine by the rate-limiting ␥-glutamylcysteine synthetase (␥-GCS) and (ii) production of GSH from ␥-GC and glycine by glutathione synthetase (14, 15). Levels of intracellular GSH content and expression of GSH biosynthetic genes have been shown to correlate with artemisinin and chloroquine sensitivity (10,(16)(17)(18). However, knocking out or overexpressing the ␥-gcs gene in Plasmodium berghei does not alter chloroquine or artemisinin sensitivity but rather affects the ability of the parasite to recrudesce after artemisinin treatment (19).The effect of GSH on modulating Plasmodium sensitivity to other antimalarials is unclear. In this study, we investigated whether inhibiting GSH biosynthesis by genetically disrupting ␥-gcs or by using a ␥-GCS inhibitor would alter P. berghei sensitivity to other standard antimalarials, such as pyrimethamine, sulfadoxine, and primaquine. MATERIALS AND METHODSP. berghei infection of mice. Six-to 10-week-old female BALB/c mice, purchased from the National Laboratory Animal Center, Mahidol University, Thailand, were used for P. berghe...

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In vitro effect of the antimalarial drug proguanil hydrochloride on viability and DNA damage in human peripheral blood lymphocytes

Cited by 6 publications

References 45 publications

Cytogenetic and oxidative status of human lymphocytes after exposure to clinically relevant concentrations of antimalarial drugs atovaquone and proguanil hydrochloride in vitro

Cytogenetic and oxidative status of human lymphocytes after exposure to clinically relevant concentrations of antimalarial drugs atovaquone and proguanil hydrochloride in vitro

An alkaline comet assay study on the antimalarial drug atovaquone in human peripheral blood lymphocytes: a study based on clinically relevant concentrations

Inhibition of Glutathione Biosynthesis Sensitizes Plasmodium berghei to Antifolates

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