Antiretroviral protease inhibitors potentiate chloroquine antimalarial activity in malaria parasites by regulating intracellular glutathione metabolism

Multipurpose Drugs Active Against Both Plasmodium spp. and Microorganisms: Potential Application for New Drug Development

Malaria, a disease caused by the protozoan parasites Plasmodium spp., is still causing serious problems in endemic regions in the world. Although the WHO recommends artemisinin combination therapies for the treatment of malaria patients, the emergence of artemisinin-resistant parasites has become a serious issue and underscores the need for the development of new antimalarial drugs. On the other hand, new and re-emergences of infectious diseases, such as the influenza pandemic, Ebola virus disease, and COVID-19, are urging the world to develop effective chemotherapeutic agents against the causative viruses, which are not achieved to the desired level yet. In this review article, we describe existing drugs which are active against both Plasmodium spp. and microorganisms including viruses, bacteria, and fungi. We also focus on the current knowledge about the mechanism of actions of these drugs. Our major aims of this article are to describe examples of drugs that kill both Plasmodium parasites and other microbes and to provide valuable information to help find new ideas for developing novel drugs, rather than merely augmenting already existing drug repurposing efforts.

The Manifesto of Pharmacoenosis: Merging HIV Pharmacology into Pathocoenosis and Syndemics in Developing Countries

Pathocoenosis and syndemics theories have emerged in the last decades meeting the frequent need of better understanding interconnections and reciprocal influences that coexistent communicable and non-communicable diseases play in a specific population. Nevertheless, the attention to pharmacokinetic and pharmacodynamics interactions of co-administered drugs for co-present diseases is to date limitedly paid to alert against detrimental pharmacological combos. Low and middle-income countries are plagued by the highest burden of HIV, tuberculosis, malaria, and helminthiasis, and they are experiencing an alarming rise in non-communicable disorders. In these settings, co-infections and comorbidities are common, but no tailored prescribing nor clinical trials are used to assess and exploit existing opportunities for the simultaneous and potentially synergistic treatment of intertwined diseases. Pharmacoenosis is the set of interactions that take place within a host as well as within a population due to the compresence of two or more diseases and their respective treatments. This framework should pilot integrated health programmes and routine clinical practice to face drug–drug interaction issues, avoiding negative co-administrations but also exploiting potential favourable ones to make the best out of the worst situations; still, to date, guiding data on the latter possibility is limited. Therefore, in this narrative review, we have briefly described both detrimental and favourable physiopathological interactions between HIV and other common co-occurring pathologies (malaria, tuberculosis, helminths, and cardiovascular disorders), and we have presented examples of advantageous potential pharmacological interactions among the drugs prescribed for these diseases from a pharmacokinetics, pharmacodynamics, and pharmacogenetics standpoint.

Repositioning of HIV Aspartyl Peptidase Inhibitors for Combating the Neglected Human Pathogen Trypanosoma cruzi

Chagas disease, caused by the flagellate parasite Trypanosoma cruzi, is a wellknown neglected tropical disease. This parasitic illness affects 6-7 million people and can lead to severe myocarditis and/or complications of the digestive tract. The changes in its epidemiology facilitate co-infection with the Human Immunodeficiency Virus (HIV), making even more difficult the diagnosis and prognosis. The parasitic infection is reactivated in T. cruzi/HIV co-infection, with the appearance of unusual manifestations in the chronic phase and the exacerbation of classical clinical signs. The therapeutic arsenal to treat Chagas disease, in all its clinical forms, is restricted basically to two drugs, benznidazole and nifurtimox. Both drugs are extremely toxic and the therapeutic efficacy is still unclear, making the clinical treatment a huge issue to be solved. Therefore, it seems obvious the necessity of new tangible approaches to combat this illness. In this sense, the repositioning of approved drugs appears as an interesting and viable strategy. The discovery of Human Immunodeficiency Virus Aspartyl Peptidase Inhibitors (HIV-PIs) represented a milestone in the treatment of Acquired Immune Deficiency Syndrome (AIDS) and, concomitantly, a marked reduction in both the incidence and prevalence of important bacterial, fungal and parasitic co-infections was clearly observed. Taking all these findings into consideration, the present review summarizes the promising and beneficial data concerning the effects of HIV-PIs on all the evolutionary forms of T. cruzi and in important steps of the parasite's life cycle, which highlight their possible application as alternative drugs to treat Chagas disease.

Malaria and HIV coinfection in sub-Saharan Africa: prevalence, impact, and treatment strategies

Malaria and HIV, two of the world's most deadly diseases, are widespread, but their distribution overlaps greatly in sub-Saharan Africa. Consequently, malaria and HIV coinfection (MHC) is common in the region. In this paper, pertinent publications on the prevalence, impact, and treatment strategies of MHC obtained by searching major electronic databases (PubMed, PubMed Central, Google Scholar, ScienceDirect, and Scopus) were reviewed, and it was found that the prevalence of MHC in SSA was 0.7%-47.5% overall. Prevalence was 0.7%-47.5% in nonpregnant adults, 1.2%-27.8% in children, and 0.94%-37% in pregnant women. MHC was associated with an increased frequency of clinical parasitemia and severe malaria, increased parasite and viral load, and impaired immunity to malaria in nonpregnant adults, children, and pregnant women, increased in placental malaria and related outcomes in pregnant women, and impaired antimalarial drug efficacy in nonpregnant adults and pregnant women. Although a few cases of adverse events have been reported in coinfected patients receiving antimalarial and antiretroviral drugs concurrently, available data are very limited and have not prompted major revision in treatment guidelines for both diseases. Artemisinin-based combination therapy and cotrimoxazole are currently the recommended drugs for treatment and prevention of malaria in HIV-infected children and adults. However, concurrent administration of cotrimoxazole and sulfadoxine-pyrimethamine in HIV-infected pregnant women is not recommended, because of high risk of sulfonamide toxicity. Further research is needed to enhance our understanding of the impact of malaria on HIV, drug-drug interactions in patients receiving antimalarials and antiretroviral drugs concomitantly, and the development of newer, safer, and more cost-effective drugs and vaccines to prevent malaria in HIV-infected pregnant women.

Simplified Reversed Chloroquines To Overcome Malaria Resistance to Quinoline-Based Drugs

Building on our earlier work of attaching a chemosensitizer (reversal agent) to a known drug pharmacophore, we have now expanded the structure-activity relationship study to include simplified versions of the chemosensitizer. The change from two aromatic rings in this head group to a single ring does not appear to detrimentally affect the antimalarial activity of the compounds. Data from in vitro heme binding and β-hematin inhibition assays suggest that the single aromatic RCQ compounds retain activities against Plasmodium falciparum similar to those of CQ, although other mechanisms of action may be relevant to their activities.

Physiochemical and cytotoxicity study of TPGS stabilized nanoemulsion designed by ultrasonication method

The main aim of the present work was to prepare TPGS stabilized D-α-Tocopherol, lemon oil, tween-80, and water nanoemulsion by low cost and highly effective sonication method. The prepared nanoemulsion showed good stability for 60days at variable temperature conditions i.e. 4, 25 and 37°C. The tolerance of the prepared nanoemulsion to salt (50mM-500mM) and pH (pH 2-pH 7.4) was also studied. The morphology and droplet size of pure and quinine loaded nanoemulsion was characterized with transmission electron microscopy. The prepared formulation was transparent and the obtained average particle size ranged between 25nm and 35nm. The nanoemulsion was found to be non toxic. The cell viability study of pure nanoemulsion carried out on Hep G2 cells revealed that the cell viability was 100%. The formulation further exhibited high quinine loading and release capacity with cumulative release up to 76±2% and 65±2% at pH 7.4 and pH 5.5 respectively. The interaction between quinine and vitamins (riboflavin, thiamine and biotin) was also carried out (aqueous medium). The study revealed that riboflavin had strong interaction with quinine and vitamins vis-à-vis thiamine and biotin.

Pharmacokinetic interactions between artesunate-mefloquine and ritonavir-boosted lopinavir in healthy Thai adults

Background

Concomitant use of anti-malarial and antiretroviral drugs is increasingly frequent in malaria and HIV endemic regions. The aim of the study was to investigate the pharmacokinetic interaction between the anti-malarial drugs, artesunate-mefloquine and the antiretroviral drug, lopinavir boosted with ritonavir (LPV/r).

Methods

The study was an open-label, three-way, sequential, cross-over, pharmacokinetic study in healthy Thai adults. Subjects received the following treatments: Period 1: standard 3-day artesunate-mefloquine combination; Period 2 (2 months wash-out): oral LPV/r 400 mg/100 mg twice a day for 14 days; and, Period 3: artesunate-mefloquine and LPV/r twice a day for 3 days. Sixteen subjects (eight females) were enrolled and pharmacokinetic parameters were determined by non-compartmental analysis.

Results

In the presence of LPV/r, artesunate C_max and systemic exposure were significantly increased by 45–80 %, while the metabolic ratio of dihydroartemisinin to artesunate was significantly reduced by 72 %. In addition, mefloquine C_max and systemic exposure were significantly reduced by 19–37 %. In the presence of artesunate-mefloquine, lopinavir C_max was significantly reduced by 22 % but without significant change in systemic drug exposure. The 90 % CI of the geometric mean ratio (GMR) of AUC_0−∞ and C_max were outside the acceptable bioequivalent range for each drug. Drug treatments were generally well tolerated with no serious adverse events. Vertigo, nausea and vomiting were the most common adverse events reported.

Conclusion

The reduction in systemic exposure of all investigated drugs raises concerns of an increased risk of treatment failure rate in co-infected patients and should be further investigated.

Piperaquine and Lumefantrine resistance in Plasmodium berghei ANKA associated with increased expression of Ca2+/H+ antiporter and glutathione associated enzymes

We investigated the mechanisms of resistance of two antimalarial drugs piperaquine (PQ) and lumefantrine (LM) using the rodent parasite Plasmodium berghei as a surrogate of the human parasite, Plasmodium falciparum. We analyzed the whole coding sequence of Plasmodium berghei chloroquine resistance transporter (Pbcrt) and Plasmodium berghei multidrug resistance gene 1(Pbmdr-1) for polymorphisms. These genes are associated with quinoline resistance in Plasmodium falciparum. No polymorphic changes were detected in the coding sequences of Pbcrt and Pbmdr1 or in the mRNA transcript levels of Pbmdr1. However, our data demonstrated that PQ and LM resistance is achieved by multiple mechanisms that include elevated mRNA transcript levels of V-type H(+) pumping pyrophosphatase (vp2), Ca(2+)/H(+) antiporter (vcx1), gamma glutamylcysteine synthetase (ggcs) and glutathione-S-transferase (gst) genes, mechanisms also known to contribute to chloroquine resistance in P. falciparum and rodent malaria parasites. The increase in ggcs and gst transcript levels was accompanied by high glutathione (GSH) levels and elevated activity of glutathione-S-transferase (GST) enzyme. Taken together, these results demonstrate that Pbcrt and Pbmdr1 are not associated with PQ and LM resistance in P. berghei ANKA, while vp2, vcx1, ggcs and gst may mediate resistance directly or modulate functional mutations in other unknown genes.

Degrees of chloroquine resistance in Plasmodium - is the redox system involved?

Chloroquine (CQ) was once a very effective antimalarial drug that, at its peak, was consumed in the hundreds of millions of doses per year. The drug acts against the Plasmodium parasite during the asexual intraerythrocytic phase of its lifecycle. Unfortunately, clinical resistance to this drug is now widespread. Questions remain about precisely how CQ kills malaria parasites, and by what means some CQ-resistant (CQR) parasites can withstand much higher concentrations of the drug than others that also fall in the CQR category. In this review we investigate the evidence for and against the proposal that CQ kills parasites by generating oxidative stress. Further, we examine a long-held idea that the glutathione system of malaria parasites plays a role in CQ resistance. We conclude that there is strong evidence that glutathione levels modulate CQ response in the rodent malaria species P. berghei, but that a role for redox in contributing to the degree of CQ resistance in species infectious to humans has not been firmly established.

HIV and malaria interactions: where do we stand?

Reversing the spread of HIV infection and the incidence of malaria constitute two of the Millenium Development Goals. However, despite recent achievements, both diseases still entail global heath problems. Furthermore, their overlapping geographical distribution raises concerns and challenges for potential immunological, clinical and therapeutic interactions. It has been reported that HIV infection increases malaria susceptibility and reduces the efficacy of antimalarial drugs. On the other hand, the effect of malaria on HIV-infected individuals has also been explored, with the parasitic infection increasing the risk of HIV disease progression and mother-to-child transmission of HIV. The spread of malaria and parasite resistance to antimalarials could also be accelerated by HIV-associated immunosuppresion. Current knowledge of the epidemiological, clinical, immunological and therapeutic interactions of the two diseases is reviewed in this article. We focus on the latest available data, pointing out key future research areas and challenges of the field.

Saquinavir inhibits the malaria parasite's chloroquine resistance transporter

The antiretroviral protease inhibitors (APIs) ritonavir, saquinavir, and lopinavir, used to treat HIV infection, inhibit the growth of Plasmodium falciparum at clinically relevant concentrations. Moreover, it has been reported that these APIs potentiate the activity of chloroquine (CQ) against this parasite in vitro. The mechanism underlying this effect is not understood, but the degree of chemosensitization varies between the different APIs and, with the exception of ritonavir, appears to be dependent on the parasite exhibiting a CQ-resistant phenotype. Here we report a study of the role of the P. falciparum chloroquine resistance transporter (PfCRT) in the interaction between CQ and APIs, using transgenic parasites expressing different PfCRT alleles and using the Xenopus laevis oocyte system for the heterologous expression of PfCRT. Our data demonstrate that saquinavir behaves as a CQ resistance reverser and that this explains, at least in part, its ability to enhance the effects of CQ in CQ-resistant P. falciparum parasites.

Drugs for malaria: something old, something new, something borrowed

Malaria was estimated to cause 800,000 deaths and 225 million cases worldwide in 2010. Worryingly, the first-line treatment currently relies on a single drug class called artemisinins, and there are signs that the parasite is becoming resistant to these drugs. The good news is that new technology has given us new approaches to drug discovery. New drugs generated this way are probably 10-15 years away from the clinic. Other antimalarials that may offer hope include those rehabilitated after not being used for some time, those that act as inhibitors of resistance mechanisms, those that limit infection while allowing protective immunity to develop, and those which are drugs borrowed from other disease treatments. All of these offer new hope of turning the tables on malaria. In parallel with the effort to develop vaccines that interrupt malaria transmission, drugs that target the parasite during transmission to the mosquito or during its pre-erythrocytic development in the liver, may allow us to terminate the parasite's spread.

Consequences of HIV infection on malaria and therapeutic implications: a systematic review

Despite recent changes in the epidemiology of HIV infection and malaria and major improvements in their control, these diseases remain two of the most important infectious diseases and global health priorities. As they have overlapping distribution in tropical areas, particularly sub-Saharan Africa, any of their clinical, diagnostic, and therapeutic interactions might have important effects on patient care and public health policy. The biological basis of these interactions is well established. HIV infection induces cellular depletion and early abnormalities of CD4+ T cells, decreases CD8+ T-cell counts and function (cellular immunity), causes deterioration of specific antigen responses (humoral immunity), and leads to alteration of innate immunity through impairment of cytolytic activity and cytokine production by natural killer cells. Therefore, HIV infection affects the immune response to malaria, particularly premunition in adolescents and adults, and pregnancy-specific immunity, leading to different patterns of disease in HIV-infected patients compared with HIV-uninfected patients. In this systematic review, we collate data on the effects of HIV on malaria and discuss their therapeutic consequences. HIV infection is associated with increased prevalence and severity of clinical malaria and impaired response to antimalarial treatment, depending on age, immunodepression, and previous immunity to malaria. HIV also affects pregnancy-specific immunity to malaria and response to intermittent preventive treatment. Co-trimoxazole (trimethoprim-sulfamethoxazole) prophylaxis and antiretroviral treatment reduce occurrence of clinical malaria; however, these therapies interact with antimalarial drugs, and new therapeutic guidelines are needed for concomitant use.

In vitro activity of antiretroviral drugs against Plasmodium falciparum

Malaria and HIV infection are both very common in many developing countries. With the increasing availability of therapy for HIV infection, it was of interest to determine whether antiretroviral drugs exert antimalarial effects. We therefore tested the in vitro activity of 19 antiretroviral drugs against the W2 and 3D7 strains of Plasmodium falciparum at concentrations up to 50 μM. None of 5 tested nucleoside reverse transcriptase inhibitors demonstrated activity. Two nonnucleoside reverse transcriptase inhibitors, efavirenz (mean 50% inhibitory concentration [IC(50)] of 22 to 30 μM against the two strains) and etravirine (3.1 to 3.4 μM), were active; nevirapine was not active. Also active were the fusion inhibitor enfuvirtide (6.2 to 7.9 μM) and the entry inhibitor maraviroc (15 to 21 μM). Raltegravir was not active. However, for all active drugs mentioned above, the IC(50)s were considerably greater than the concentrations achieved with standard dosing. The effects most likely to be clinically relevant were with HIV protease inhibitors. Of the tested compounds, activity was seen with lopinavir (2.7 to 2.9 μM), atazanavir (3.3 to 13.0 μM), saquinavir (5.0 to 12.1 μM), nelfinavir (6.5 to 12.1 μM), ritonavir (9.5 to 10.9 μM), tipranavir (15.5 to 22.3 μM), and amprenavir (28.1 to 40.8) but not darunavir. Lopinavir was active at levels well below those achieved with standard dosing of coformulated lopinavir-ritonavir. Lopinavir also demonstrated modest synergy with the antimalarial lumefantrine (mean fractional inhibitory concentration index of 0.66 for W2 and 0.53 for 3D7). Prior data showed that lopinavir-ritonavir also extends the pharmacokinetic exposure of lumefantrine. Thus, when used to treat HIV infection, lopinavir-ritonavir may have clinically relevant antimalarial activity and also enhance the activity of antimalarials.

Synergy of the antiretroviral protease inhibitor indinavir and chloroquine against malaria parasites in vitro and in vivo

Many malaria-endemic areas are also associated with high rates of human immunodeficiency virus (HIV) infection. An understanding of the chemotherapeutic interactions that occur during malaria and HIV co-infections is important. Our previous studies have demonstrated that some antiretroviral protease inhibitors are effective in inhibiting Plasmodium falciparum growth in vitro. Currently, studies examining the interactions between antiretroviral protease inhibitors and antimalarial drugs are being conducted, but the data are limited. In this study, we examined the synergistic interactions between the antiretroviral protease inhibitor indinavir and chloroquine (CQ) in chloroquine-resistant and chloroquine-sensitive malaria parasites in vitro and in vivo. In vitro, by using modified fixed-ratio isobologram method, fractional inhibitory concentrations index (FICI) was calculated to indicate the interaction between the two drugs. The results demonstrated that indinavir interacted synergistically with chloroquine against both chloroquine-sensitive P. falciparum clone 3D7 (mean FICI 0.784) and multidrug-resistant P. falciparum clone Dd2 (mean FICI 0.599). In vivo drug interactions were measured using a 4-day suppressive test in a rodent malaria model infected with Plasmodium chabaudi. We observed that indinavir enhanced the antimalarial activity of chloroquine against both the chloroquine-sensitive line P. chabaudi ASS and the chloroquine-resistant line P. chabaudi ASCQ. More importantly, chloroquine had a 100% clearance of asexual parasites when used in combination with indinavir at an appropriate dose ratio (10 mg/kg CQ + 1.8 g/kg indinavir) where there was no obvious toxicity. We conclude from this study that the combination of indinavir and chloroquine may become a novel antimalarial drug regimen.

Antimalarial effects of human immunodeficiency virus protease inhibitors in rhesus macaques

The antimalarial activity of the human immunodeficiency virus protease inhibitors indinavir and saquinavir was evaluated in rhesus macaques for the first time. Indinavir effectively suppressed the growth of Plasmodium cynomolgi and Plasmodium knowlesi in vivo after a 7- or 3-day treatment, respectively, with clinically relevant doses, whereas saquinavir showed only weak activity against P. cynomolgi.

HIV Protease Inhibitors: Effect on the Opportunistic Protozoan Parasites

The impact of highly active antiretroviral therapy (HAART) in the natural history of AIDS disease has been allowed to prolong the survival of people with HIV infection, particularly whose with increased HIV viral load. Additionally, the antiretroviral therapy could exert a certain degree of protection against parasitic diseases. A number of studies have been evidenced a decrease in the incidence of opportunistic parasitic infections in the era of HAART. Although these changes have been attributed to the restoration of cell-mediated immunity, induced by either non-nucleoside reverse transcriptase inhibitors or HIV protease inhibitors, in combination with at least two nucleoside reverse transcriptase inhibitors included in HAART, there are evidence that the control of these parasitic infections in HIV-positive persons under HAART, is also induced by the inhibition of the proteases of the parasites. This review focuses on the principal available data related with therapeutic HIV-protease inhibitors and their in vitro and in vivo effects on the opportunistic protozoan parasites.

HIV proteinase inhibitors target the Ddi1-like protein of Leishmania parasites

HIV proteinase inhibitors reduce the levels of Leishmania parasites in vivo and in vitro, but their biochemical target is unknown. We have identified an ortholog of the yeast Ddi1 protein as the only member of the aspartic proteinase family in Leishmania parasites, and in this study we investigate this protein as a potential target for the drugs. To date, no enzyme assay has been developed for the Ddi1 proteins, but Saccharomyces cerevisiae lacking the DDI1 gene secrete high levels of protein into the medium. We developed an assay in which these knockout yeast were functionally complemented to low secretion by introduction of genes encoding Ddi1 orthologs from Leishmania major or humans. Plasmid alone controls gave no complementation. Treatment of the Ddi1 transformants with HIV proteinase inhibitors showed differential effects dependent on the origin of the Ddi1. Dose responses allowed calculation of IC₅₀ values; e.g., for nelfinavir, of 3.4 μM (human Ddi1) and 0.44 μM (Leishmania Ddi1). IC₅₀ values with Leishmania constructs mirror the potency of inhibitors against parasites. Our results show that Ddi1 proteins are targets of HIV proteinase inhibitors and indicates the Leishmania Ddi1 as the likely target for these drugs and a potential target for antiparasitic therapy.—White, R. E., Powell, D. J., Berry, C. HIV proteinase inhibitors target the Ddi1-Like protein of Leishmania parasites.

Implication of intracellular glutathione and its related enzymes on resistance of malaria parasites to the antimalarial drug arteether

The control of malaria has been complicated by the increasing resistance of malarial parasites to multiple drugs. However, artemisinin-based drugs offer hope in the fight against drug-resistant parasites. The mode of action of these drugs remains unclear, but evidence suggests a role for free radicals in their mechanism of action. In this study, we examined the relationship between the intracellular levels of glutathione (GSH) and antioxidant enzymes and resistance to the artemisinin-based drug arteether in experimentally selected arteether-resistant Plasmodium vinckei. GSH plays a critical role in the detoxification and protection of cells against oxidative stress. Our comparative studies showed a significant (2.9-fold) increase in the GSH level in arteether-resistant parasites as compared to arteether-sensitive parasites. Simultaneously, significantly increased activities of glutathione reductase, glutathione-S transferase and glucose-6-phosphate dehydrogenase and decreased activity of superoxide dismutase were recorded in resistant parasites; the activity of glutathione peroxidase was comparable in arteether-sensitive and -resistant parasites. Artemisinin derivatives act by generating free radicals and our results indicate that glutathione's antioxidant effects may counteract that drug effect and thereby contribute to the parasites' resistance to arteether and other artemisinin-based antimalarials.

Targeting glutathione by dimethylfumarate protects against experimental malaria by enhancing erythrocyte cell membrane scrambling

The balance between GSH-levels and oxidative stress is critical for cell survival. The GSH-levels of erythrocytes are dramatically decreased during infection with Plasmodium spp. We therefore investigated the consequences of targeting GSH for erythrocyte and Plasmodium survival in vitro and in vivo using dimethylfumarate (DMF) at therapeutically established dosage. We first show that noninfected red blood cells (RBC) exposed to DMF undergo changes typical of apoptosis or eryptosis, such as cell shrinkage and cell membrane scrambling with subsequent phosphatidylserine (PS) exposure. DMF did not induce appreciable hemolysis. DMF-triggered PS exposure was mediated by intracellular GSH depletion and reversed by the antioxidative N-acetyl-l-cysteine. DMF treatment controlled intraerythrocyte DNA amplification and in vitro parasitemia of Plasmodium falciparum-infected RBC. In vivo, DMF treatment had no effect on RBC count or GSH levels in noninfected mice. Consistent with its effects on infected RBC, DMF treatment abrogated parasitemia and enhanced the survival of mice infected with Plasmodium berghei from 0% to 60%. In conclusion, DMF sensitizes the erythrocytes to the effect of Plasmodium infection on PS exposure, thus accelerating the clearance of infected erythrocytes. Accordingly, DMF treatment favorably influences the clinical course of malaria. As DMF targets mechanisms within the host cell, it is not likely to generate resistance of the pathogen.