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1.
Exp Parasitol ; 224: 108097, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33736972

RESUMO

The quest for the development of a novel antimalarial drug informed the decision to subject phytol to in vivo trials following a demonstration of therapeutic potential against chloroquine sensitive strain of Plasmodium falciparum under in vitro condition. On this basis, the in vivo anti-Plasmodium berghei activity of phytol including the ameliorative effects of the compound on P. berghei-associated anaemia and organ damage were investigated. Mice were infected with chloroquine-sensitive strain of P. berghei and were treated with phytol at a dose of 10 and 20 mg/kg body weight (BW) for four days. The levels of parasitemia, packed cell volume and redox sensitive biomarkers of liver, brain and spleen tissues were determined. Our result revealed that phytol significantly (p < 0.05) suppressed the multiplication of P. berghei in a dose-dependent manner. Additionally, the phytol significantly (p < 0.05) ameliorated the P. berghei-induced anaemia and brain damage. Data from the present study demonstrated that phytol has suppressive effect on P. berghei and could ameliorate some P. berghei-induced pathological changes.


Assuntos
Malária/tratamento farmacológico , Fitol/uso terapêutico , Plasmodium berghei/efeitos dos fármacos , Análise de Variância , Anemia/tratamento farmacológico , Anemia/parasitologia , Animais , Antimaláricos/farmacologia , Antimaláricos/uso terapêutico , Encéfalo/parasitologia , Encéfalo/patologia , Cloroquina/farmacologia , Cloroquina/uso terapêutico , Relação Dose-Resposta a Droga , Feminino , Hematócrito , Fígado/parasitologia , Fígado/patologia , Malária/sangue , Malária/parasitologia , Malária/patologia , Masculino , Camundongos , Oxirredução/efeitos dos fármacos , Parasitemia/tratamento farmacológico , Fitol/farmacologia , Distribuição Aleatória , Baço/parasitologia , Baço/patologia
2.
J Ethnopharmacol ; 266: 113424, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33010404

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria is a life-threatening health problem worldwide and treatment remains a major challenge. Natural products from medicinal plants are credible sources for better anti-malarial drugs. AIM OF THE STUDY: This study aimed at assessing the in vitro and in vivo antiplasmodial activities of the hydroethanolic extract of Bridelia atroviridis bark. MATERIALS AND METHODS: The phytochemical characterization of Bridelia atroviridis extract was carried out by High-Performance Liquid Chromatography-Mass spectrometry (HPLC-MS). The cytotoxicity test on Vero cells was carried out using the resazurin-based assay while the in vitro antiplasmodial activity was determined on Plasmodium falciparum (Dd2 strain, chloroquine resistant) using the SYBR green I-based fluorescence assay. The in vivo assay was performed on Plasmodium berghei-infected rats daily treated for 5 days with distilled water (10 mL/kg) for malaria control, 25 mg/kg of chloroquine sulfate for positive control and 50, 100 and 200 mg/kg of B. atroviridis extract for the three test groups. Parasitaemia was daily monitored using 10% giemsa-staining thin blood smears. At the end of the treatment, animals were sacrificed, blood was collected for hematological and biochemical analysis while organs were removed for biochemical and histopathological analyses. RESULTS: The HPLC-MS analysis data of B. atroviridis revealed the presence of bridelionoside D, isomyricitrin, corilagin, myricetin and 5 others compounds not yet identified. Bridelia atroviridis exhibited good in vitro antiplasmodial activity with the IC50 evaluated at 8.08 µg/mL and low cytotoxicity with the median cytotoxic concentration (CC50) higher than 100 µg/mL. B. atroviridis extract significantly reduced the parasitemia (p < 0.05) with an effective dose-50 (ED-50) of 89 mg/kg. B. atroviridis also prevented anemia, leukocytosis and liver and kidneys impairment by decrease of transaminases, ALP, creatinine, uric acid, and triglycerides concentrations. As well, B. atroviridis extract decreased some pro-inflammatory cytokines (TNF-α, IL-1ß, IL-6) levels and significantly improved the anti-inflammatory status (P < 0.01) of infected animals marked by a decrease of IL-10 concentration. These results were further confirmed by the improved of antioxidant status and the quasi-normal microarchitecture of the liver, kidneys and spleen in test groups. Overall, the hydroethanolic bark extract of Bridelia atroviridis demonstrated antimalarial property and justified its use in traditional medicine to manage malaria disease.


Assuntos
Antimaláricos/farmacologia , Euphorbiaceae/química , Extratos Vegetais/farmacologia , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/administração & dosagem , Antimaláricos/isolamento & purificação , Chlorocebus aethiops , Cloroquina/farmacologia , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Feminino , Concentração Inibidora 50 , Malária/tratamento farmacológico , Malária/parasitologia , Masculino , Espectrometria de Massas , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Ratos , Ratos Wistar , Células Vero
3.
J Ethnopharmacol ; 266: 113427, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33022339

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria is caused by infection with some species of Plasmodium parasite which leads to adverse alterations in physical and hematological features of infected persons and ultimately results in death. Antrocaryon micraster is used to treat malaria in Ghanaian traditional medicine. However, there is no scientific validation of its anti-malaria properties. The plant does not also have any chemical fingerprint or standardization parameters. AIM OF THE STUDY: This study sought to evaluate the anti-malaria activity of standardized A. micraster stem bark extract (AMSBE) and its effect on mean survival time (MST) and body weight reduction of Plasmodiumberghei infested mice. And to study the effect of treatment of AMSBE on hematological indices of the P. berghei infested mice in order to partly elucidate its anti-malarial mechanism of action. MATERIALS AND METHODS: Malaria was induced in female ICR mice by infecting them with 0.2 mL of blood (i.p.) containing 1.0 × 107P. berghei-infested RBCs from a donor mouse and leaving them without treatment for 3 days. AMSBE or Lonart (standard control) was then orally administered at 50, 200 and 400 mg/kg or 10 mg/kg once daily for 4 consecutive days. The untreated control received sterile water. Malaria parasitemia reduction, anti-malarial activity, mean change in body weight and MST of the parasitized mice were evaluated. Furthermore, changes in white blood cells (WBCs), red blood cells (RBCs), platelets count, hemoglobin (HGB), hematocrit (HCT) and mean corpuscular volume (MCV) were also determined in the healthy animals before infection as baseline and on days 3, 5 and 8 after infection by employing complete blood count. Standardization of AMSBE was achieved by quantification of its constituents and chemical fingerprint analysis using UHPLC-MS. RESULTS: Administration of AMSBE, standardized to 41.51% saponins and 234.960 ± 0.026 mg/g of GAE phenolics, produced significant (P < 0.05) reduction of parasitemia development, maximum anti-malaria activity of 46.01% (comparable to 32.53% produced by Lonart) and significantly (P < 0.05) increased body weight and MST of P. berghei infected mice compared to the untreated control. Moreover, there were significant (P > 0.05) elevation in WBCs, RBCs, HGB, HCT and platelets in the parasitized-AMSBE (especially at 400 mg/kg p.o.) treated mice compared to their baseline values. Whereas, the non-treated parasitized control recorded significant reduction (P < 0.05) in all the above-mentioned parameters compared to its baseline values. The UHPLC-MS fingerprint of AMSBE revealed four compounds with their retention times, percentage composition in their chromatograms and m/z of the molecular ions and fragments in the spectra. CONCLUSIONS: These results show that A. micraster stem bark possessed significant anti-malaria effect and also has the ability to abolish body weight loss, leucopenia, anemia and thrombocytopenia in P. berghei infected mice leading to prolonged life span. The UHPLC-MS fingerprint developed for AMSBE can be used for rapid authentication and standardization of A. micraster specimens and herbal preparations produced from its hydroethanolic stem bark extract to ensure consistent biological activity. The results justify A. micraster's use as anti-malaria agent.


Assuntos
Anacardiaceae/química , Antimaláricos/farmacologia , Malária/tratamento farmacológico , Extratos Vegetais/farmacologia , Plasmodium berghei/efeitos dos fármacos , Animais , Antimaláricos/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Gana , Malária/parasitologia , Medicina Tradicional Africana , Camundongos , Camundongos Endogâmicos ICR , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Casca de Planta , Extratos Vegetais/administração & dosagem
4.
PLoS Negl Trop Dis ; 14(12): e0008947, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33338041

RESUMO

Leishmaniasis is among the world's most neglected diseases. Dogs are the main reservoirs/hosts of Leishmania infantum, causative agent of both canine and human visceral leishmaniosis. Canine leishmaniasis (CanL) represents a public health problem as one of the most prevalent zoonotic diseases worldwide. Current therapeutics present drawbacks; thus, there is a need for more effective, safer, and cheaper drugs. The aim of this study was to evaluate and to compare the efficacy of oral administration of artesunate or meglumine antimoniate/allopurinol in dogs with clinical leishmaniasis. Forty-two dogs with naturally occurring clinical leishmaniasis were included in this open-label, simple randomized positive-control clinical field trial with 6 months of follow-up. Dogs received meglumine antimoniate 100 mg/kg/day and allopurinol 30 mg/kg/day for 28 days (control group, n = 26) or artesunate 25 mg/kg/day for 6 days (test group, n = 16). The animals were evaluated for their clinical evolution, parasite load (by qPCR) and humoral response at different time points: 0, 30, 90, and 180 days after treatment. Data analyses showed a significant improvement in both groups in clinical scores, parasitemia and antibody titers after treatment. Compared to the control group, the artesunate group showed significantly lower clinical score (P = 0.0001), lower parasitemia (P = 0.0001) and antibody titers after 6 months of follow-up. Compared to baseline values, a rapid, significant reduction (P < 0.012) in antibody levels, 2.28- versus 3.04-fold for the control versus artesunate groups, respectively, was observed 30 days after treatment. Antibody levels continued to decrease further in the artesunate group, where 58% of cases became seronegative at the 6-month follow-up. All qPCR-positive dogs were negative after treatment with artesunate, while 14.3% remained positive with the appearance of two new cases in the control group. Artesunate was well tolerated, and no side effects were recorded. Treatment failures were similar in both groups with 27.27% (6/22), including 18.18% (4/22) mortality in the control group, versus 26.66% (4/15), including 13.33% (2/15) mortality in the artesunate group. This is the first report showing the potential of artesunate in the treatment of dogs with clinical leishmaniasis. Artesunate showed higher efficacy than the current first-line treatment for CanL without any adverse effects. It could be a good alternative chemotherapy for CanL, and may be considered for further studies in human leishmaniases. Further clinical trials are needed to confirm these findings, to determine if there are relapses after treatment and if dogs remain infective to sandflies, to define the ideal therapeutic dosage and duration of treatment with artesunate.


Assuntos
Alopurinol/uso terapêutico , Antiprotozoários/uso terapêutico , Artesunato/uso terapêutico , Doenças do Cão/tratamento farmacológico , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/veterinária , Antimoniato de Meglumina/uso terapêutico , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Masculino , Carga Parasitária/veterinária , Parasitemia/tratamento farmacológico , Zoonoses
5.
Cochrane Database Syst Rev ; 9: CD010458, 2020 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-32892362

RESUMO

BACKGROUND: Plasmodium vivax malaria has a persistent liver stage that causes relapse of the disease and continued P vivax transmission. Primaquine (PQ) is used to clear the liver stage of the parasite, but treatment is required for 14 days. Primaquine also causes haemolysis in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Tafenoquine (TQ) is a new alternative to PQ with a longer half-life and can be used as a single-dose treatment. OBJECTIVES: To assess the effects of tafenoquine 300 mg (single dose) on preventing P vivax relapse. SEARCH METHODS: We searched the following up to 3 June 2020: the Cochrane Infectious Diseases Group Specialized Register; CENTRAL; MEDLINE; Embase; and three other databases. We also searched the WHO International Clinical Trial Registry Platform and the metaRegister of Controlled Trials for ongoing trials using "tafenoquine" and "malaria" as search terms up to 3 June 2020. SELECTION CRITERIA: Randomized controlled trials (RCTs) that gave TQ to prevent relapse in people with P vivax malaria. We planned to include trials irrespective of whether participants had been screened for G6PD enzyme deficiency. DATA COLLECTION AND ANALYSIS: All review authors independently extracted data and assessed risk of bias. As true relapse and reinfection are difficult to differentiate in people living in endemic areas, studies report "recurrences" of infection as a proxy for relapse. We carried out meta-analysis where appropriate, and gave estimates as risk ratios (RR) with 95% confidence intervals (CI). We assessed the certainty of the evidence using the GRADE approach. MAIN RESULTS: Three individually randomized RCTs met our inclusion criteria, all in endemic areas, and thus reporting recurrence. Trials compared TQ with PQ or placebo, and all participants received chloroquine (CQ) to treat the asexual infection). In all trials, pregnant and G6PD-deficient people were excluded. Tafenoquine 300 mg single dose versus no treatment for relapse prevention Two trials assessed this comparison. TQ 300 mg single dose reduces P vivax recurrences compared to no antihypnozoite treatment during a six-month follow-up, but there is moderate uncertainty around effect size (RR 0.32, 95% CI 0.12 to 0.88; 2 trials, 504 participants; moderate-certainty evidence). In people with normal G6PD status, there is probably little or no difference in any type of adverse events (2 trials, 504 participants; moderate-certainty evidence). However, we are uncertain if TQ causes more serious adverse events (2 trials, 504 participants; very low-certainty evidence). Both RCTs reported a total of 23 serious adverse events in TQ groups (One RCT reported 21 events) and a majority (15 events) were a drop in haemoglobin level by > 3g/dl (or >30% reduction from baseline). Tafenoquine 300 mg single dose versus primaquine 15 mg/day for 14 days for relapse prevention Three trials assessed this comparison. There is probably little or no difference between TQ and PQ in preventing recurrences (proxy measure for relapse) up to six months of follow-up (RR 1.04, 95% CI 0.8 to 1.34; 3 trials, 747 participants; moderate-certainty evidence). In people with normal G6PD status, there is probably little or no difference in any type of adverse events (3 trials, 747 participants; moderate-certainty evidence). We are uncertain if TQ can cause more serious adverse events compared to PQ (3 trials, 747 participants; very low-certainty evidence). Two trials had higher point estimates against TQ while the other showed the reverse. Most commonly reported serious adverse event in TQ group was a decline in haemoglobin level (19 out of 29 events). Some other serious adverse events, though observed in the TQ group, are unlikely to be caused by it (Hepatitis E infection, limb abscess, pneumonia, menorrhagia). AUTHORS' CONCLUSIONS: TQ 300 mg single dose prevents relapses after clinically parasitologically confirmed P vivax malaria compared to no antihypnozoite treatment, and with no difference detected in studies comparing it to PQ to date. However, the inability to differentiate a true relapse from a recurrence in the available studies may affect these estimates. The drug is untested in children and in people with G6PD deficiency. Single-dose treatment is an important practical advantage compared to using PQ for the same purpose without an overall increase in adverse events in non-pregnant, non-G6PD-deficient adults.


Assuntos
Aminoquinolinas/administração & dosagem , Antimaláricos/administração & dosagem , Malária Vivax/tratamento farmacológico , Primaquina/administração & dosagem , Prevenção Secundária , Adulto , Aminoquinolinas/efeitos adversos , Antimaláricos/efeitos adversos , Cloroquina/administração & dosagem , Cloroquina/efeitos adversos , Esquema de Medicação , Deficiência de Glucosefosfato Desidrogenase/complicações , Humanos , Parasitemia/tratamento farmacológico , Placebos , Primaquina/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva
6.
Am J Trop Med Hyg ; 103(5): 1910-1917, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32815508

RESUMO

Liver transaminase elevations after treatment in malaria volunteer infection studies (VISs) have raised safety concerns. We investigated transaminase elevations from two human Plasmodium vivax VISs where subjects were treated with chloroquine (n = 24) or artefenomel (n = 8) and compared them with studies in Thailand (n = 41) and Malaysia (n = 76). In the VISs, alanine transaminase (ALT) increased to ≥ 2.5 × upper limit of normal (ULN) in 11/32 (34%) volunteers, peaking 5-8 days post-treatment. Transaminase elevations were asymptomatic, were not associated with elevated bilirubin, and resolved by day 42. The risk of an ALT ≥ 2.5 × ULN increased more than 4-fold (odds ratio [OR] 4.28; 95% CI: 1.26-14.59; P = 0.02) for every log10 increase in the parasite clearance burden (PCB), defined as the log-fold reduction in parasitemia 24 hours post-treatment. Although an elevated ALT ≥ 2.5 × ULN was more common after artefenomel than after chloroquine (5/8 [63%] versus 6/24 [25%]; OR 5.0; 95% CI: 0.91-27.47; P = 0.06), this risk disappeared when corrected for PCB. Peak ALT also correlated with peak C-reactive protein (R = 0.44; P = 0.012). Elevations in ALT (≥ 2.5 × ULN) were less common in malaria-endemic settings, occurring in 1/41 (2.5%) Thai patients treated with artefenomel, and in none of 76 Malaysians treated with chloroquine or artemisinin combination therapy. Post-treatment transaminase elevations are common in experimental P. vivax infection but do not appear to impact on participant safety. Although the mechanism of these changes remains uncertain, host inflammatory response to parasite clearance may be contributory.


Assuntos
Adamantano/análogos & derivados , Alanina Transaminase/sangue , Antimaláricos/uso terapêutico , Hepatopatias/tratamento farmacológico , Malária Vivax/tratamento farmacológico , Peróxidos/uso terapêutico , Plasmodium vivax/isolamento & purificação , Adamantano/uso terapêutico , Adulto , Artemisininas/uso terapêutico , Cloroquina/uso terapêutico , Estudos de Coortes , Feminino , Humanos , Hepatopatias/sangue , Hepatopatias/parasitologia , Testes de Função Hepática , Malária Vivax/sangue , Malária Vivax/parasitologia , Malásia , Masculino , Parasitemia/tratamento farmacológico , Tailândia , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-32660993

RESUMO

Previously, ivermectin (1 to 10 mg/kg of body weight) was shown to inhibit the liver-stage development of Plasmodium berghei in orally dosed mice. Here, ivermectin showed inhibition of the in vitro development of Plasmodium cynomolgi schizonts (50% inhibitory concentration [IC50], 10.42 µM) and hypnozoites (IC50, 29.24 µM) in primary macaque hepatocytes when administered as a high dose prophylactically but not when administered in radical cure mode. The safety, pharmacokinetics, and efficacy of oral ivermectin (0.3, 0.6, and 1.2 mg/kg) with and without chloroquine (10 mg/kg) administered for 7 consecutive days were evaluated for prophylaxis or radical cure of P. cynomolgi liver stages in rhesus macaques. No inhibition or delay to blood-stage P. cynomolgi parasitemia was observed at any ivermectin dose (0.3, 0.6, and 1.2 mg/kg). Ivermectin (0.6 and 1.2 mg/kg) and chloroquine (10 mg/kg) in combination were well-tolerated with no adverse events and no significant pharmacokinetic drug-drug interactions observed. Repeated daily ivermectin administration for 7 days did not inhibit ivermectin bioavailability. It was recently demonstrated that both ivermectin and chloroquine inhibit replication of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro Further ivermectin and chloroquine trials in humans are warranted to evaluate their role in Plasmodium vivax control and as adjunctive therapies against COVID-19 infections.


Assuntos
Antimaláricos/farmacologia , Cloroquina/farmacologia , Ivermectina/farmacologia , Fígado/efeitos dos fármacos , Malária/tratamento farmacológico , Plasmodium cynomolgi/efeitos dos fármacos , Animais , Antimaláricos/sangue , Antimaláricos/farmacocinética , Disponibilidade Biológica , Cloroquina/sangue , Cloroquina/farmacocinética , Esquema de Medicação , Combinação de Medicamentos , Sinergismo Farmacológico , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/parasitologia , Ivermectina/sangue , Ivermectina/farmacocinética , Fígado/parasitologia , Macaca mulatta , Malária/parasitologia , Masculino , Parasitemia/tratamento farmacológico , Plasmodium cynomolgi/crescimento & desenvolvimento , Plasmodium cynomolgi/patogenicidade , Cultura Primária de Células , Esquizontes/efeitos dos fármacos , Esquizontes/crescimento & desenvolvimento
8.
Am J Trop Med Hyg ; 103(3): 1329-1334, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32342841

RESUMO

Reductions in malaria morbidity have been reported following azithromycin mass drug administration (MDA) for trachoma. The recent Macrolides Oraux pour Reduire les Deces avec un Oeil sur la Resistance (MORDOR) trial reported a reduction in child mortality following biannual azithromycin MDA. Here, we investigate the effects of azithromycin MDA on malaria at the MORDOR-Malawi study site. A cluster-randomized double-blind placebo-controlled trial, with 15 clusters per arm, was conducted. House-to-house census was updated biannually, and azithromycin or placebo syrup was distributed to children aged 1-59 months for a total of four biannual distributions. At baseline, 12-month, and 24-month follow-up visits, a random sample of 1,200 children was assessed for malaria with thick and thin blood smears and hemoglobin measurement. In the community-level analysis, there was no difference in the prevalence of parasitemia (1.0% lower in azithromycin-treated communities; 95% CI: -8.2 to 6.1), gametocytemia (0.7% lower in azithromycin-treated communities; 95% CI: -2.8 to 1.5), or anemia (1.7% lower in azithromycin-treated communities; 95% CI: -8.1 to 4.6) between placebo and azithromycin communities. Further interrogation of the data at the individual level, both per-protocol (including only those who received treatment 6 months previously) and by intention-to-treat, did not identify differences in parasitemia between treatment arms. In contrast to several previous reports, this study did not show an effect of azithromycin MDA on malaria parasitemia at the community or individual levels.


Assuntos
Anemia/epidemiologia , Antibacterianos/administração & dosagem , Azitromicina/administração & dosagem , Malária/tratamento farmacológico , Parasitemia/tratamento farmacológico , Mortalidade da Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Lactente , Malária/epidemiologia , Malária/parasitologia , Masculino , Administração Massiva de Medicamentos , Parasitemia/epidemiologia , Parasitemia/parasitologia , Prevalência
9.
Int J Infect Dis ; 95: 399-405, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32320811

RESUMO

BACKGROUND: Artemisinin resistance described as increased parasite clearance time (PCT) is rare in Africa. More sensitive methods such as qPCR might better characterize the clearance phenotype in sub-Saharan Africa. METHODS: PCT is explored in Mali using light microscopy and qPCR after artesunate for uncomplicated malaria. In two villages, patients were followed for 28 days. Blood smears and spots were collected respectively for microscopy and qPCR. Parasitemia slope half-life was calculated after microscopy. Patient residual parasitemia were measured by qPCR. RESULTS: Uncorrected adequate clinical and parasitological responses (ACPR) observed in Faladje and Bougoula-Hameau were 78% and 92%, respectively (p=0.01). This reached 100% for both after molecular correction. Proportions of 24H microscopy positive patients in Faladje and Bougoula-Hameau were 97.2% and 72%, respectively (p<0.0001). Slope half-life was 2.8h in Faladje vs 2H in Bougoula-Hameau (p<0.001) and Proportions of 72H patients with residual parasitemia were 68.5% and 40% in Faladje and Bougoula-Hameau, respectively (p=0.003). The mean residual parasitemia was 2.9 in Faladje vs. 0.008 in Bougoula-Hameau (p=0.002). Although artesunate is efficacious in Mali, the longer parasite clearance time with submicroscopic parasitemia observed may represent early signs of developing P. falciparum resistance to artemisinins.


Assuntos
Malária Falciparum/parasitologia , Plasmodium falciparum , Antimaláricos/uso terapêutico , Artesunato/uso terapêutico , Criança , Feminino , Humanos , Malária Falciparum/tratamento farmacológico , Masculino , Mali , Microscopia , Parasitemia/tratamento farmacológico , Plasmodium falciparum/genética , Plasmodium falciparum/imunologia , Reação em Cadeia da Polimerase em Tempo Real
10.
Am J Trop Med Hyg ; 103(1): 378-393, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32314694

RESUMO

Malaria volunteer infection studies (VISs) accelerate new drug and vaccine development. In the induced blood-stage malaria (IBSM) model, volunteers are inoculated with erythrocytes infected with Plasmodium falciparum. Observations of elevated liver enzymes in the IBSM model with new chemical entities (NCEs) promoted an analysis of available data. Data were reviewed from eight IBSM studies of seven different NCEs, plus two studies with the registered antimalarial piperaquine conducted between June 2013 and January 2017 at QIMR Berghofer, Brisbane, Australia. Alanine aminotransferase (ALT) was elevated (> 2.5 times the upper limit of normal [×ULN]) in 20/114 (17.5%) participants. Of these, 8.9% (10/114) had moderate increases (> 2.5-5 × ULN), noted in seven studies of six different NCEs ± piperaquine or piperaquine alone, and 8.9% (10/114) had severe elevations (> 5 × ULN), occurring in six studies of six different NCEs ± piperaquine. Aspartate aminotransferase (AST) was elevated (> 2.5 × ULN) in 11.4% (13/114) of participants, across six of the 10 studies. Bilirubin was > 2 × ULN in one participant. Published data from other VIS models, using sporozoite inoculation by systemic administration or mosquito feeding, also showed moderate/severe liver enzyme elevations. In conclusion, liver enzyme elevations in IBSM studies are most likely multifactorial and could be caused by the model conditions, that is, malaria infection/parasite density and/or effective parasite clearance, or by participant-specific risk factors, acetaminophen administration, or direct hepatotoxicity of the test drug. We make recommendations that may mitigate the risk of liver enzyme elevations in future VISs and propose measures to assist their interpretation, should they occur.


Assuntos
Alanina Transaminase/metabolismo , Antimaláricos/efeitos adversos , Aspartato Aminotransferases/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/epidemiologia , Voluntários Saudáveis , Malária Falciparum/tratamento farmacológico , Parasitemia/tratamento farmacológico , Acrilamidas/efeitos adversos , Adamantano/efeitos adversos , Adamantano/análogos & derivados , Adulto , Aminopiridinas/efeitos adversos , Aminoquinolinas/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Transfusão de Eritrócitos , Eritrócitos/parasitologia , Feminino , Compostos Ferrosos/efeitos adversos , Compostos Heterocíclicos de 4 ou mais Anéis/efeitos adversos , Humanos , Indóis/efeitos adversos , Isoquinolinas/efeitos adversos , Masculino , Metalocenos/efeitos adversos , Peróxidos/efeitos adversos , Piperazinas/efeitos adversos , Plasmodium falciparum , Primaquina/efeitos adversos , Pirimidinas/efeitos adversos , Quinolinas/efeitos adversos , Compostos de Espiro/efeitos adversos , Sulfonas/efeitos adversos , Triazóis/efeitos adversos , Adulto Jovem
11.
Trends Parasitol ; 36(5): 413-426, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32298629

RESUMO

Antimalarial drugs are vital for treating malaria and controlling transmission. Measuring drug efficacy in the field requires large clinical trials and thus we have identified proxy measures of drug efficacy such as the parasite clearance curve. This is often assumed to measure the rate of drug activity against parasites and is used to predict optimal treatment regimens required to completely clear a blood-stage infection. We discuss evidence that the clearance curve is not measuring the rate of drug killing. This has major implications for how we assess optimal treatment regimens, as well as how we prioritise new drugs in the drug development pipeline.


Assuntos
Antimaláricos/uso terapêutico , Malária Falciparum/tratamento farmacológico , Malária Falciparum/parasitologia , Antimaláricos/farmacologia , Humanos , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/fisiologia , Resultado do Tratamento
12.
Transfusion ; 60(4): 799-805, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32129497

RESUMO

BACKGROUND: Risk of transfusion-transmitted (TT) malaria is mainly associated with whole blood (WB) or red blood cell (RBC) transfusion. Risk mitigation relies mostly on donor deferral while a limited number of countries perform blood testing, both negatively impacting blood availability. This study investigated the efficacy of the pathogen reduction system using amustaline and glutathione (GSH) to inactivate Plasmodium falciparum in WB. STUDY DESIGN AND METHODS: WB units were spiked with ring stage P. falciparum infected RBCs. Parasite loads were measured in samples at time of infection, after 24 hours at room temperature (RT), and after a 24-hour incubation at RT post-treatment with 0.2 mM amustaline and 2 mM GSH. Serial 10-fold dilutions of the samples were inoculated to RBC cultures and maintained up to 4 weeks. Parasitemia was quantified by cytometry. RESULTS: The P. falciparum viability assay has a limit of detection of a single live parasite per sample. Input parasite titer was >5.7 log10 TCID50 per mL. A 24-hour incubation at RT paused parasite development in controls, but they retained viability and infectivity when tested in culture. In contrast, no infectious parasites were detected in the amustaline/GSH-treated sample after 4 weeks of culture. CONCLUSION: A robust level of P. falciparum inactivation was achieved in WB using amustaline/GSH treatment. Parasite log reduction was >5.7 log10 TCID50 per mL. Development of such a pathogen reduction system may provide an opportunity to reduce the risk of TT malaria and improve blood availability.


Assuntos
Acridinas/farmacologia , Glutationa/farmacologia , Malária Falciparum/prevenção & controle , Viabilidade Microbiana/efeitos dos fármacos , Compostos de Mostarda Nitrogenada/farmacologia , Segurança do Sangue/métodos , Eritrócitos/microbiologia , Eritrócitos/parasitologia , Humanos , Malária Falciparum/sangue , Malária Falciparum/transmissão , Carga Parasitária , Parasitemia/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento
13.
Mem Inst Oswaldo Cruz ; 115: e190389, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32074167

RESUMO

BACKGROUND: Chagas disease, which is caused by the protozoan Trypanosoma cruzi, is endemic to Latin America and mainly affects low-income populations. Chemotherapy is based on two nitrocompounds, but their reduced efficacy encourages the continuous search for alternative drugs. Our group has characterised the trypanocidal effect of naphthoquinones and their derivatives, with naphthoimidazoles derived from ß-lapachone (N1, N2 and N3) being the most active in vitro. OBJECTIVES: In the present work, the effects of N1, N2 and N3 on acutely infected mice were investigated. METHODS: in vivo activity of the compounds was assessed by parasitological, biochemical, histopathological, immunophenotypical, electrocardiographic (ECG) and behavioral analyses. FINDINGS: Naphthoimidazoles led to a decrease in parasitaemia (8 dpi) by reducing the number of bloodstream trypomastigotes by 25-50% but not by reducing mortality. N1 protected mice from heart injury (15 dpi) by decreasing inflammation. Bradycardia was also partially reversed after treatment with N1 and N2. Furthermore, the three compounds did not reverse hepatic and renal lesions or promote the improvement of other evaluated parameters. MAIN CONCLUSION: N1 showed moderate trypanocidal and promising immunomodulatory activities, and its use in combination with benznidazole and/or anti-arrhythmic drugs as well as the efficacy of its alternative formulations must be investigated in the near future.


Assuntos
Doença de Chagas/tratamento farmacológico , Naftoquinonas/uso terapêutico , Nitroimidazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , Doença Aguda , Animais , Anti-Inflamatórios , Modelos Animais de Doenças , Eletrocardiografia , Masculino , Camundongos , Naftoquinonas/química , Nitroimidazóis/química , Parasitemia/tratamento farmacológico , Fatores de Tempo , Tripanossomicidas/química
14.
Am J Trop Med Hyg ; 103(3): 1315-1318, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32067628

RESUMO

The relationship between malaria and malnutrition is complicated, and existence of one may predispose or exacerbate the other. We evaluated the relationship between malaria parasitemia and nutritional status in children living in communities participating in a cluster-randomized trial of biannual azithromycin compared with placebo for prevention of childhood mortality. Data were collected during the low malaria transmission and low food insecurity season. Parasitemia was not associated with weight-for-height Z-score (24 months: P = 0.11 azithromycin communities, P = 0.75 placebo communities), weight-for-age Z-score (24 months: P = 0.83 azithromycin, P = 0.78 placebo), height-for-age Z-score (24 months: P = 0.30 azithromycin, P = 0.87 placebo), or mid-upper arm circumference (24 months: P = 0.12 azithromycin, P = 0.56 placebo). There was no statistically significant evidence of a difference in the relationship in communities receiving azithromycin or placebo. During the low transmission season, there was no evidence that malaria parasitemia and impaired nutritional status co-occur in children.


Assuntos
Antibacterianos/administração & dosagem , Azitromicina/administração & dosagem , Malária/epidemiologia , Administração Massiva de Medicamentos , Estado Nutricional , Parasitemia/epidemiologia , Pré-Escolar , Feminino , Humanos , Lactente , Malária/tratamento farmacológico , Malária/parasitologia , Malária/transmissão , Masculino , Níger/epidemiologia , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Parasitemia/transmissão , Estações do Ano
15.
Malar J ; 19(1): 71, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054478

RESUMO

BACKGROUND: Naphthoquine (NQ) is a suitable partner anti-malarial for the artemisinin-based combination therapy (ACT), which is recommended to be taken orally as a single-dose regimen. The metabolism of NQ was mainly mediated by CYP2D6, which is well-known to show gender-specific differences in its expression. In spite of its clinical use, there is limited information on the pharmacokinetics of NQ, and no data are available for females. In this study, the effect of gender on the pharmacokinetics and antiplasmodial efficacy of NQ in rodents was evaluated. The underlying factors leading to the potential gender difference, i.e., plasma protein binding and metabolic clearance, were also evaluated. METHODS: The pharmacokinetic profiles of NQ were investigated in healthy male or female rats after a single oral administration of NQ. The antiplasmodial efficacy of NQ was studied in male or female mice infected with Plasmodium yoelii. The recrudescence and survival time of infected mice were also recorded after drug treatment. Plasma protein binding of NQ was determined in pooled plasma collected from male or female mice, rat or human. In vitro metabolism experiments were performed in the liver microsomes of male or female mice, rat or human. RESULTS: The results showed that the gender of rats did not affect NQ exposure (AUC0-t and Cmax) significantly (P > 0.05). However, a significant (P < 0.05) longer t1/2 was found for NQ in male rats (192.1 ± 47.7), compared with female rats (143.9 ± 27.1). Slightly higher but not significant (P > 0.05) antiplasmodial activity was found for NQ in male mice (ED90, 1.10 mg/kg) infected with P. yoelii, compared with female mice (ED90, 1.67 mg/kg). The binding rates of NQ to plasma protein were similar in males and females. There was no metabolic difference for NQ in male and female mice, rat or human liver microsomes. CONCLUSIONS: These results indicated that the pharmacokinetic profiles of NQ were similar between male and female rats, except for a longer t1/2 in male rats. The difference was not associated with plasma protein binding or hepatic metabolic clearance. Equivalent antiplasmodial activity was found for NQ in male and female mice infected with P. yoelii. This study will be helpful for the rational design of clinical trials for NQ.


Assuntos
1-Naftilamina/análogos & derivados , Aminoquinolinas/farmacologia , Aminoquinolinas/farmacocinética , Antimaláricos/farmacologia , Antimaláricos/farmacocinética , 1-Naftilamina/administração & dosagem , 1-Naftilamina/farmacocinética , 1-Naftilamina/farmacologia , Administração Oral , Aminoquinolinas/administração & dosagem , Aminoquinolinas/sangue , Animais , Antimaláricos/administração & dosagem , Antimaláricos/sangue , Área Sob a Curva , Proteínas Sanguíneas/metabolismo , Cloroquina/administração & dosagem , Cromatografia Líquida , Relação Dose-Resposta a Droga , Feminino , Humanos , Modelos Lineares , Malária/tratamento farmacológico , Malária/metabolismo , Malária/parasitologia , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos ICR , Microssomos Hepáticos/metabolismo , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Plasmodium yoelii/efeitos dos fármacos , Ligação Proteica , Ratos , Ratos Wistar , Fatores Sexuais
16.
BMC Complement Med Ther ; 20(1): 24, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-32020885

RESUMO

BACKGROUND: Citrus plants particularly lemon (Citrus limon L.) concoctions are ethno-medically used for treatment of infectious diseases including malaria. Therefore, we set an experiment to investigate the effects of lemon decoction in mice infected with Plasmodium berghei ANKA parasites. METHODS: Antimalarial activity was determined using Rane's curative test on 25 Theiler's albino mice. Twenty mice were each injected with 2 × 107 infected red blood cells (iRBCs). The mice were divided into four groups, consisting of five mice per group. Each group received an oral dose of either 5% carboxymethyl cellulose/placebo (negative infected control), lemon decoction (Citrus limon [CILI extract]) alone or a combination of artemether/lumefantrine (A/LU, 28 mg/kg) and CILI extract and A/LU alone. A fifth group of mice consisted of uninfected mice as parasite-negative control. RESULTS: Within 72 hours after initiation of treatment, the mean percentage parasitemia ± standard deviation of the CILI extract group (24.2% ± 9.83%) was lower compared to placebo group (40.0% ± 14.78%), p = 0.037. CILI extract group was found to have an increased survival rate (11 days ± 1.6 days) as compared to placebo group (8.6 days ± 3.4 days), p = 0.226. Mice in the combination group (A/LU + CILI extract) had the highest mean counts in terms of hemato-immunological parameters, whereas those in the CILI extract alone had the lowest hematocrit levels. The study also found that mice that received a combination of CILI extract and A/LU exhibited a decreased lag time with regards to time required to clear 99% of parasites (58.8 h vs. 64.2 h, p = 0.681) as compared to the A/LU alone group. CONCLUSION: Lemon decoction demonstrated antimalarial activity in mice infected with P. berghei ANKA through parasites suppression by 39% as compared to those received placebo. However, when used alone, lemons did not suffice as a cure but in combination with standard antimalarials, lemons promoted early parasite clearance with an improved hematological parameters.


Assuntos
Antimaláricos/farmacologia , Citrus/química , Malária/tratamento farmacológico , Parasitemia/tratamento farmacológico , Extratos Vegetais/farmacologia , Animais , Combinação Arteméter e Lumefantrina/farmacologia , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Masculino , Camundongos , Plasmodium berghei/efeitos dos fármacos , Tanzânia
17.
Malar J ; 19(1): 54, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32005233

RESUMO

BACKGROUND: Tracking and understanding artemisinin resistance is key for preventing global setbacks in malaria eradication efforts. The ring-stage survival assay (RSA) is the current gold standard for in vitro artemisinin resistance phenotyping. However, the RSA has several drawbacks: it is relatively low throughput, has high variance due to microscopy readout, and correlates poorly with the current benchmark for in vivo resistance, patient clearance half-life post-artemisinin treatment. Here a modified RSA is presented, the extended Recovery Ring-stage Survival Assay (eRRSA), using 15 cloned patient isolates from Southeast Asia with a range of patient clearance half-lives, including parasite isolates with and without kelch13 mutations. METHODS: Plasmodium falciparum cultures were synchronized with single layer Percoll during the schizont stage of the intraerythrocytic development cycle. Cultures were left to reinvade to early ring-stage and parasitaemia was quantified using flow cytometry. Cultures were diluted to 2% haematocrit and 0.5% parasitaemia in a 96-well plate to start the assay, allowing for increased throughput and decreased variability between biological replicates. Parasites were treated with 700 nM of dihydroartemisinin or 0.02% dimethyl sulfoxide (DMSO) for 6 h, washed three times in drug-free media, and incubated for 66 or 114 h, when samples were collected and frozen for PCR amplification. A SYBR Green-based quantitative PCR method was used to quantify the fold-change between treated and untreated samples. RESULTS: 15 cloned patient isolates from Southeast Asia with a range of patient clearance half-lives were assayed using the eRRSA. Due to the large number of pyknotic and dying parasites at 66 h post-exposure (72 h sample), parasites were grown for an additional cell cycle (114 h post-exposure, 120 h sample), which drastically improved correlation with patient clearance half-life compared to the 66 h post-exposure sample. A Spearman correlation of - 0.8393 between fold change and patient clearance half-life was identified in these 15 isolates from Southeast Asia, which is the strongest correlation reported to date. CONCLUSIONS: eRRSA drastically increases the efficiency and accuracy of in vitro artemisinin resistance phenotyping compared to the traditional RSA, which paves the way for extensive in vitro phenotyping of hundreds of artemisinin resistant parasites.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Malária Falciparum/diagnóstico , Parasitemia/diagnóstico , Plasmodium falciparum/isolamento & purificação , Resistência a Medicamentos , Eritrócitos/parasitologia , Citometria de Fluxo , Corantes Fluorescentes , Meia-Vida , Humanos , Malária Falciparum/tratamento farmacológico , Compostos Orgânicos , Parasitemia/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Povidona , Reação em Cadeia da Polimerase em Tempo Real/métodos , Dióxido de Silício
18.
Rev Soc Bras Med Trop ; 53: e20190477, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049205

RESUMO

INTRODUCTION: Benznidazole (BZL) and Nifurtimox (NFX) are the pharmacological treatment for acute phase Chagas Disease (CD); however, therapy resistance and residual mortality development remain important unresolved issues. Posaconazole (POS) has shown a trypanocidal effect in vivo and in vitro. Thus, this study aimed at comparing the T. Cruzi parasitic load-reducing effect of the combination of BZL+POS against that of monotherapy with either, during acute phase CD, in an experimental murine model. METHODS: Nineteen Wistar rats were randomly allocated to four groups and inoculated with the trypomastigotes of T. cruzi strain´s JChVcl1. The rats were administered anti-parasites from day 20-29 post-infection. The Pizzi and Brener method was used for parasitemia measurement. Longitudinal data analysis for the continuous outcome of repeated measures was performed using parasitemia as the outcome measured at days 20, 22, 24, 27, and 29 post-infection. RESULTS: All four groups had similar parasitic loads (p=0.143) prior to therapy initiation. Among the three treatment groups, the BZL+POS (n=5) group showed the highest mean parasitic load reduction (p=0.000) compared with the control group. Likewise, the BZL+POS group rats showed an earlier therapeutic effect and were the only ones without parasites in their myocardial samples. CONCLUSIONS: Treatment of acute phase CD with BZL+POS was more efficacious at parasitemia and myocardial injury reduction, compared with monotherapy with either.


Assuntos
Doença de Chagas/tratamento farmacológico , Nitroimidazóis/administração & dosagem , Parasitemia/tratamento farmacológico , Triazóis/administração & dosagem , Tripanossomicidas/administração & dosagem , Doença Aguda , Animais , DNA de Protozoário , Modelos Animais de Doenças , Progressão da Doença , Quimioterapia Combinada , Carga Parasitária , Ratos , Ratos Wistar
19.
Eur J Pharm Sci ; 144: 105208, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31883446

RESUMO

The Malaria burden was an escalating global encumbrance and need to be addressed with critical care. Anti-malarial drug discovery was integrated with supervised machine learning (ML) models to identify potent thiazolyl-traizine derivatives. This assimilated approach of Direct Kernel-based Partial Least Squares regression (DKPLS) with molprint 2D fingerprints in Quantitative Structure Activity Relationship models was utilized to map the knowledge of known actives and to design novel molecules. This QSAR study had revealed the structural features required for better antimalarial activity. Two of the molecules which were designed based on the results of this QSAR study, had shown good percentage of parasitemia against both chloroquine sensitive (3D7) and chloroquine resistant (Dd2) strains of Plasmodium falciparum respectively. The IC50 of 201D and 204D was 3.02 and 2.17 µM against chloroquine resistant Dd2 strain of Plasmodium falciparum. This result had proved the efficiency of a multidisciplinary approach of medicinal chemistry and machine learning for the design of novel potent anti-malarial compounds.


Assuntos
Antimaláricos/química , Antimaláricos/síntese química , Aprendizado de Máquina , Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Triazinas/química , Cloroquina/uso terapêutico , Parasitemia/tratamento farmacológico
20.
J Ethnopharmacol ; 248: 112334, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31669101

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Coccinia barteri (Hook. F.) is traditional used in Southeast of Nigeria in management of fever. This study aimed to evaluate the antimalarial activities of hydro-methanol crude extract and solvent fractions of Coccinia barteri leaf. MATERIALS AND METHODS: Two animal models employed for the study were, 4-day suppressive and curative assays against chloroquine sensitive Plasmodium berghei NK65. Level of parasitaemia, mean survival time (MST), anal temperature and weight loss were measured to assess antimalarial efficacy of the extract/fractions. Chloroquine (10 mg kg-1) was used as positive control. Chemo-profile of extract was evaluated using GC-MS, HPLC techniques and standard phytochemical analysis. Preliminary toxicity test was done using modified Lorke's method. RESULTS: The crude extract (100-400 mg kg-1) and solvent fractions (20-80 mg kg-1) demonstrated antimalarial activity in both models compared to controls. Semi purified fractions of the extract produced stronger percentage chemosuppression and inhibition of parasite. The % inhibition of the fractions, hexane, chloroform, ethyl acetate and aqueous at 80 mg kg-1 were 96.0 0, 95.29, 89.86 and 96.00% respectively on day 8 (D8). While on D14, 100% parasite clearance, indicating cure was obtained for hexane, chloroform and aqueous fraction treatment groups, no death occurred in these groups. Ethyl acetate fraction treated groups lived longer but were not fully protected. Some marker compounds were identified. CONCLUSIONS: These results support the use of C. barteri as malaria remedy and potential source of antimalarial templates. Long acting parasitaemia reduction effect indicates its possible combination potential in poly-herbal combination therapy.


Assuntos
Antimaláricos/farmacologia , Cucurbitaceae , Malária/tratamento farmacológico , Extratos Vegetais/farmacologia , Folhas de Planta , Plasmodium berghei/efeitos dos fármacos , Solventes/química , Animais , Antimaláricos/isolamento & purificação , Antimaláricos/toxicidade , Cloroquina/farmacologia , Cucurbitaceae/química , Cucurbitaceae/toxicidade , Modelos Animais de Doenças , Feminino , Malária/parasitologia , Masculino , Camundongos , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Folhas de Planta/química , Folhas de Planta/toxicidade , Plasmodium berghei/crescimento & desenvolvimento
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