Efficacy Of Artesunate Research Articles

Effect of Co-administration of Vitamin A and Artesunate in Malaria-Infected Albino Mice

Malaria is a potentially fatal illness that results from infection by parasitic protozoa, which spread to humans via the bites of mosquitoes that have already been infected with the parasite. This research examines the impact of the simultaneous administration of Vitamin A and Artesunate on Plasmodium berghei-infected albino mice. A cohort of sixteen (16) albino mice, with a mean weight of 28g and indeterminate gender, were subjected to P. berghei inoculation. The mice were separated into four groups, each consisting of four animals. Artesunate was administered to Group A, distilled water was administered to Group B, Group C received antioxidant treatment in the form of vitamin A, and Group D was subjected to a combination treatment of Artesunate and Vitamin A. The study monitored the parasitemia level, hematocrit (PVC), percentage mortality rate, and change in body weight following the administration of various treatments, including an antimalarial drug (Artesunate), distilled water, Vitamin A, and a combination therapy of both Artesunate and Vitamin A. The co-administration of vitamin A and Artesunate may decrease the effectiveness of Artesunate in treating malaria infection. The research illustrates the intricate relationship between Artesunate and antioxidant (vitamin A) in mice infected with malaria. The efficacy of Artesunate in clearing the parasite was demonstrated by the reduction of Parasitaemia levels from +2(++) on the 5th day to +3 (+++) on the 7th day, followed by a decrease to +2(++) on the 9th day, and ultimately to +1(+) Parasitaemia on the 10th day. The co-administration of Vitamin A and Artesunate resulted in a reduction of the latter's efficacy in treating malaria, particularly in cases where the parasitemia level was at +3(+++) on the 5th, seventh, and 11th days and +2(++) on the ninth day. This procedure suggests that Vitamin A acted as an antagonist to the antimalarial effects of Artesunate.
 Furthermore, the mortality rate was 50%, and the PCV was reduced compared to Group A. Artesunate, a pro-oxidant that generates free oxygen radicals that act against the parasite. However, the presence of antioxidants like Vitamin A potentially counteracted the effects of pro-oxidants, indicating some form of pharmacological antagonism. The research findings indicate that the co-administration of vitamin A and Artesunate may reduce therapeutic effectiveness. Clinical interventions are recommended to be implemented to regulate the simultaneous administration of Artesunate and Vitamin A, as this may impact the therapeutic objective of malaria treatment.

Efficacy of artesunate in asthma: based on network pharmacology and molecular docking.

Asthma has brought great economicburdens to community. Artesunate has shown certain effects on asthma experimentally, but relevant mechanisms are not clear. This study aims to systemically evaluate the efficacy and safety of artesunate and its metabolite, dihydroartemisinin (DHA), in asthma, based on network pharmacology and molecular docking. All the information before March 1st, 2022 was collected. We evaluated the physicochemistry and Adsorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET) properties of artesunate and DHA by SwissADME and ADMETlab, identified targets of artesunate and DHA from SwissTargetPrediction and PharmMapper, and acquired genes participating in asthma from GeneCards and DisGeNET. Overlapping targets and hub genes were identified with Maximal Clique Centrality (MCC) algorithm in Cytoscape, cytoHubba. Enrichment analyses were performed to analyze the potential mechanisms and target sites. Molecular docking was utilized to investigate the receptor-ligand interactions on Autodock Vina and visualized in PyMOL. Artesunate and DHA showed acceptable druglikeness and safety for clinical application. A total of 282 targets of compounds and 7,997 targets of asthma were identified. 172 overlapping targets were visualized in a compound-target and protein-protein interaction network. Biofunction analysis showed the clustering associations with biosynthesis and metabolism of and response to steroid hormone, immune and inflammatory response, airway hyperresponsiveness, airway remodeling and cell survival and death regulation. CCND1, CASP3, MTOR, ERBB2, MAPK3, EGFR, MAP2K1, PTGS2, JAK2, and CASP8 were identified as the hub targets. Molecular docking indicated 10 stable receptor-ligand interactions, except for CASP3. Artesunate has the potential to be a potent and safe anti-asthmatic agent based on diverse therapeutic mechanisms and acceptable safety.

Efficacy and safety of artesunate for patients with IgA nephropathy: a study protocol for a multicenter, double-blind, randomized, placebo-controlled trial

BackgroundIgA nephropathy is the most common glomerular disease and is a common cause of progression to end-stage renal disease in patients with kidney diseases. Proteinuria levels are critical for the prognosis of patients with IgA nephropathy, but many patients are still unable to effectively control their proteinuria levels after receiving RAAS blockers. Antimalarial drugs have shown good efficacy in the treatment of kidney disease in previous studies; however, there have been no strictly designed randomized controlled trials to confirm the clinical efficacy of artesunate for treating IgA nephropathy patients. Therefore, we designed this clinical trial to compare the effect of artesunate versus placebo in patients with IgA nephropathy.MethodsThis study is a randomized, double-blind, three-group-parallel, placebo-controlled clinical trial. One hundred and twenty eligible IgA nephropathy patients at risk of progression will be randomly divided into the artesunate 100-mg group, artesunate 50-mg group, and placebo group. Changes in proteinuria and renal function will be measured 6 months after the intervention. The levels of Gd-IgA1 and anti-Gd-IgA1 in the patient’s blood will also be tested to explore the possible immune mechanisms.DiscussionClinical evidence supporting artesunate treatment of IgA nephropathy is currently lacking, and we expect that the results of this trial will provide high-quality clinical evidence for artesunate as a treatment option for IgA nephropathy in the future.Trial registrationChinese Clinical Trial Registry ChiCTR2000038104. Registered on 10 September 2020

NIR-responsive polydopamine-based calcium carbonate hybrid nanoparticles delivering artesunate for cancer chemo-photothermal therapy

Artesunate (AS), the first-line treatment of malaria with a satisfactory safety profile, has been repurposed as a potential anticancer candidate as it mainly generates reactive oxygen species (ROS) through its intrinsic endoperoxide bridge reacting with ferrous-based catalysts to suppress cancer cell growth. However, further clinical translation of AS is hindered by the attenuated anticancer efficacy due to insufficient ROS generation. Herein, we rationally integrated hydrophobic-modified AS (hAS) with biomimetic polydopamine (PDA) and biomineral calcium carbonate to fabricate high AS-loaded nanomedicine (Ca-PDA/hAS@PEG) for cancer chemo-photothermal therapy, which exerted anticancer effects in the following ways: (1) the heat was generated when PDA was irradiated by near-infrared (NIR) light for photothermal therapy. Meanwhile, the increased temperature accelerated the production of ROS from hAS, thus enhancing the anticancer efficacy of hAS-based chemotherapy; (2) hAS-mediated chemotherapy boosted the cancer inhibition effect of photothermal therapy by arousing the intracellular ROS levels in the presence of endogenous ferrous ions and sensitizing cancer cells to thermal ablation; (3) the integration of calcium carbonate into the nanoparticle facilitated the pH-responsive drug release for precise treatment. Such hybrid nanoparticles exhibited a combinational antitumor effect of photothermal therapy and chemotherapy in vivo with no systemic toxicity. Taken together, our work presents a facile strategy to improve the anticancer efficacy of AS by combining chemical modification and photothermal therapy-assisted endoperoxide bridge cleavage, which may offer opportunities to pave the way for clinical translation of AS-based nanomedicines. Statement of significanceThe clinical translation of artesunate (AS) is hindered by the attenuated anticancer efficacy due to insufficient ROS generation. Herein, we rationally integrated hydrophobic-modified AS (hAS) with biomimetic polydopamine (PDA) and biomineral calcium carbonate to fabricate high AS-loaded nanomedicine (Ca-PDA/hAS@PEG) for improved cancer chemo-photothermal therapy. The heat generated from PDA in response to near-infrared light irradiation could locally ablate tumor as well as accelerate the production of ROS by hAS, thus enhancing the anticancer efficacy of hAS-based chemotherapy. On the other hand, hAS-based chemotherapy amplified the intracellular oxidative stress, sensitizing cancer cells to thermal ablation. Our work presents a facile strategy to improve the anticancer efficacy of AS by combining chemical modification and photothermal therapy-assisted endoperoxide bridge cleavage.

A comparative study of valaciclovir, valganciclovir, and artesunate efficacy in reactivated HHV-6 and HHV-7 infections associated with chronic fatigue syndrome/myalgic encephalomyelitis.

This study aimed to compare the efficacy of valaciclovir, valganciclovir, and artesunate in treating chronic reactivated human herpesvirus type 6 (HHV-6) and human herpesvirus type 7 (HHV-7) infection associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). From 255 patients (192 cases) with reactivated HHV-6 and HHV-7 infections (confirmed based on blood leukocyte PCR), valaciclovir, valganciclovir, or artesunate was administered at a dose of 3000, 900, and 100 mg/day, respectively, for 3 months (study group). The control group consisted of similar patients with ME/CFS (n = 63) not taking any antiviral drugs. The significance of differences was evaluated by Student's t-test and the nonparametric criterion-the number of Z-signs. Negative PCR results in patients with HHV-6 and HHV-7 treated with valaciclovir was achieved in 26% and 23% (first month), 34%, and 28% (second month), 37% and 34% of cases (third month), respectively (P < 0.05; Z < Z0.05 ). The same results with valganciclovir were obtained in 35% and 33% (first month), 44% and 39% (second month), 48% and 45% of cases (third month), but with artesunate in 44% and 41% (first month), 57% and 53% (second month), 68% and 63% of cases (third month), respectively (P < 0.05; Z < Z0.05 ). Artesunate is more effective than valganciclovir and valacyclovir in patients with ME/CFS with reactivated HHV-6 and HHV-7 infections.

The preclinical discovery and development of rectal artesunate for the treatment of malaria in young children: a review of the evidence

ABSTRACT Introduction Plasmodium falciparum, the deadliest malaria parasite, kills hundreds of thousands of people per year, mainly young children in Sub-Saharan Africa. Artesunate suppositories are recommended as pre-referral malaria treatment in remote endemic areas for severely ill children to prevent progression of the disease and to provide extra time for patients until the definitive severe malaria treatment can be administered. Areas covered The authors provide an overview of the discovery of artesunate and its different formulations focusing on rectal administration, summarizing key studies concerning the pharmacokinetic, pharmacodynamic, safety, tolerability and efficacy of rectal artesunate leading to WHO recommendation and market authorization in Africa. In addition, studies on acceptance and adherence to rectal artesunate administration and the post-launch status are also covered. Expert opinion Efforts by ministries of health in malaria endemic countries together with international health organizations should establish and enforce guidelines to ensure the correct use of artesunate suppositories only as pre-referral medication in presumed severe malaria cases to minimize the risk of abuse as a monotherapy for treatment of uncomplicated malaria. The priority is to not jeopardize the efficacy of artesunate and to prevent resistance development against this valuable drug class in Africa.

Enhancing the antimalarial activity of artesunate.

The global challenge to the treatment of malaria is mainly the occurrence of resistance of malaria parasites to conventionally used antimalarials. Artesunate, a semisynthetic artemisinin compound, and other artemisinin derivatives are currently used in combination with selected active antimalarial drugs in order to prevent or delay the emergence of resistance to artemisinin derivatives. Several methods, such as preparation of hybrid compounds, combination therapy, chemical modification and the use of synthetic materials to enhance solubility and delivery of artesunate, have been employed over the years to improve the antimalarial activity of artesunate. Each of these methods has advantages it bestows on the efficacy of artesunate. This review discussed the various methods employed in enhancing the antimalarial activity of artesunate and delaying the emergence of resistance of parasite to it.

THE RESULTS OF THE STUDY OF IMPORTANT CLINICAL ASPECTS OF TTV INFECTION: SPECTRUM OF MANIFESTATIONS, ASSOCIATION WITH MINOR IMMUNODEFICIENCIES, EFFICACY OF ARTESUNATE

Background. TT, or Torque teno virus, is a widespread population of DNA-containing simple virus from the Anelloviridae family that can cause both chronic hepatitis and extrahepatic lesions, but is still an under-studied pathogen that lacks effective antiviral drugs.&#x0D; Aim of the study: to study the spectrum of clinical phenotype, immune status and efficacy of artesunate in chronic reactivated TTV infection in humans.&#x0D; Materials and methods. In this retrospective clinical case study, we examined the results of case histories of 67 patients aged 19 to 52 years (36 men, 31 women) with reactivated TTV infection (PCR data from blood cells) who received artesunate therapy. 38 additional patients with reactivated TTV infection with similar age, gender distribution, and clinical picture who did not receive artesunate constituted the control group.&#x0D; Immunological study included the study of indicators of total blood count, subpopulation composition of lymphocytes using laser flow cytofluorimetry (cytofluorometer Epics Xl, USA) and indirect immunofluorescence method with monoclonal antibodies to CD (CD3+, CD3+ CD4+, CD3+CD8+, CD3-CD19+, CD3-CD16+CD56 +, CD3+CD16+ CD56+) (Beckman Coulter reagents, USA). Phagocytosis was evaluated according to a latex test to determine the index of phagocytosis, the number of active phagocytes and phagocytic blood capacity. Serum immunoglobulin concentrations of the major classes (M, G, A) were determined by Mancini simple radial immunodiffusion. Concentration of IgE, IgD and IgG subclasses (IgG1, IgG2, IgG3, IgG4) in serum was measured by enzyme-linked immunosorbent assay (VectorBEST, RF). Serum mannose binding lectin concentration and myeloperoxidase activity were determined by enzyme immunoassay.&#x0D; Within 1 month of therapy, artesunate was administered at a dose of 50 mg twice a day 1 time for 12 hours orally after meals, and for 2-3 months with insufficient effectiveness of the previous course - at a dose of 50 mg three times a day 1 time for 8 hours orally after food.&#x0D; Statistical analysis of information was performed using structural and comparative analyzes. Methods of variational statistics were applied with the calculation of the parametric index of the Student’s T-test with the index of confidence probability p and the nonparametric criterion of the number of signs Z by Urbach Yu.V.&#x0D; Results of the study and discussion. Hepatic lesions were reported in only 34%, while non-hepatic forms of the disease - in 66% of cases. Extrahepatic manifestations were determined by chronic fatigue syndrome (34%), neuropsychiatric symptoms associated with temporal mesial sclerosis (32%), mononucleosis-like syndrome (16%), vasculopathy of small cerebral vessels (14%), encephalitis (5% of cases) . All patients were immunocompromised individuals. Only one case was diagnosed with HIV infection, and all other patients suffered from minor immunodeficiencies, including deficiency of natural killer T-lymphocytes (49%), natural killer cells (30%), cytotoxic T-lymphocytes (24%), IgE and/or IgD, mannose-binding lectin (15%), myeloperoxidase (12%), IgA (4%), and idiopathic CD4+ T-cell lymphopenia (3% of cases). Artesunate therapy was effective in 62% of cases (p&lt;0.05; Z&lt;Z0.05), providing removal of virus DNA from blood cells according to PCR for 1-3 months. In 21% of cases there was a partial and 17% - complete resistance of the virus to artesunate. This is 10-15% more effective than previously reported in alpha interferon preparations, with better tolerability and ease of use for artesunate. According to PCR, the mean number of viral particles in blood cells during therapy decreased from 97 to 11 thousand in the sample (p&lt;0.05; Z&lt;Z0.05).&#x0D; Conclusions. TTV is not exclusively hepatotropic, but a multitropic opportunistic virus that is reactivated in an immunosuppressed organism, including primary minor immunodeficiencies with damage to various branches of the immune system. Artesunate, given a three-month course of 100-150 mg/day orally, provides the elimination of viral DNA from blood cells in 62% of cases with satisfactory tolerability, so it can be considered as a new promising drug for the treatment of this infection.

Artesunate targets oral tongue squamous cell carcinoma via mitochondrial dysfunction-dependent oxidative damage and Akt/AMPK/mTOR inhibition.

Although mitochondrial metabolism has recently gained attention as a promising therapeutic strategy in cancer, little is known on the impact of mitochondrial respiration inhibition on oral tongue squamous cell carcinoma (OTSCC). Using in vitro and in vivo OTSCC models, our work demonstrates that inducing mitochondrial dysfunction by anti-malarial drug artesunate is effective in targeting OTSCC stem-cell like and bulk cells. Artesunate inhibits anchorage-independent colony formation, proliferation and survival in all tested OTSCC cell lines although with varying efficacy. Artesunate displays preferential anti-OTSCC activity by sparing normal cells. Mechanism analysis indicates that artesunate inhibits mitochondrial respiration via suppressing mitochondrial complex I and II but not IV or V, resulting in oxidative stress and damage. Interestingly, OTSCC cells that are more sensitive to artesunate have higher level of basal mitochondrial respiration and reversed respiratory capacity compared to those with less sensitivity to artesunate, suggesting the varying dependence on mitochondrial respiration among OTSCC cell lines. In addition, artesunate induces oxidative stress and damage in cells with low sensitivity to a less extent than in those with high sensitivity. We confirm that mitochondrial respiration inhibition is required for the action of artesunate in OTSCC. Mitochondrial dysfunction by artesunate further activates AMPK and suppresses Akt/mTOR. Importantly, the in vitro observations are reproducible in vivo OTSCC xenograft mouse model. Our findings provide pre-clinical evidence on the efficacy of artesunate and emphasize the therapeutic value of targeting mitochondrial respiration in OTSCC.

Treatment of Uncomplicated Malaria among Under-Five Children: A Systematic Review

Most uncomplicated malaria dominated countries have embraced the recommended first-line treatment of uncomplicated malaria. Artemisinin-based combination therapies such as Artemether-Lumefantrine, Artesunate + Amodiaquine and Dihydroartemisinin-Piperaquine have shown to be effective with Artemether-Lumefantrine and considered the most effective and approved by WHO. The study collected and reviewed recent randomized controlled trials for the treatment of uncomplicated malaria under five children. Eligibility criteria for the selected studies were based on the use of tools such as PICO (T) and data extraction tools such as REPOSE guidelines, PRISMA statement and eligibility criteria. This study includes only RCTs on the treatment of uncomplicated malaria under 5 s. Data was analyzed through comparative-narrative analysis. This study found 8 studies. Selected studies had a total of 10,682 participants within the age range of 0 - 59 months with the diagnosis of uncomplicated malaria and an MCP range of 2000 - 200,000 treated with different antimalarial drugs. Artesunate + Amodiaquine and Dihydroartemisinin-Piperaquine and Artemether-Lumefantrine drugs were found to be consistent in the treatment of uncomplicated malaria under 5 s within three days. Findings show that Artemether-Lumefantrine, Artesunate + Amodiaquine and Dihydroartemisinin-Piperaquine were the best drugs of choice due to their fast rate in fever reduction and parasite clearance. The efficacy of Artesunate + Amodiaquine and Dihydroartemisinin-Piperaquine is comparable to Dihydroartemisinin-Piperaquine. The study concludes that Artesunate + Amodiaquine and Dihydroartemisinin-Piperaquine can also be drugs of choice along with the well-known and utilized Artemether-Lumefantrine combination because of the fever reduction and parasite clearance within the first three days duration.

Efficacy of Artesunate against Pseudomonas aeruginosa Biofilm Mediated by Iron.

Pseudomonas aeruginosa is capable of causing a variety of chronic infections due to the formation of biofilms. Iron is essential for growth of Pseudomonas aeruginosa, and therapies that interfere with iron may help treat P. aeruginosa infections. Herein, we investigated whether artesunate, which is a type of iron-dependent drug, could influence Pseudomonas aeruginosa biofilm formation and structure, including the underlying mechanisms. Artesunate could enhance twitching motility significantly and decrease the proportion of surviving cells in Pseudomonas aeruginosa biofilms in a dose-dependent manner. Artesunate treatment also reduced biofilm thickness, diffusion in the biomass, and the content of Fe(II). However, changes in biofilm structure and ion concentration were very similar following treatment with 512 μg/ml and 1024 μg/ml artesunate. Interestingly, both biofilm structure and surviving cell fraction were recovered after iron supplementation. These results suggest that artesunate interferes with Pseudomonas aeruginosa biofilms by decreasing bacterial viability and enhancing twitching motility in an iron-independent manner.

Therapeutic efficacy of artesunate\u2013amodiaquine and artemether\u2013lumefantrine combinations for uncomplicated malaria in 10 sentinel sites across Ghana: 2015\u20132017

BackgroundRoutine surveillance on the therapeutic efficacy of artemisinin-based combination therapy (ACT) has been ongoing in Ghana since 2005. The sixth round of surveillance was conducted between 2015 and 2017 to determine the therapeutic efficacy of artesunate–amodiaquine (AS–AQ) and artemether–lumefantrine (AL) in 10 sentinel sites across the country.MethodsThe study was a one-arm, prospective, evaluation of the clinical, parasitological, and haematological responses to directly observed treatment with AS–AQ and AL among children 6 months to 9 years old with uncomplicated falciparum malaria. The WHO 2009 protocol on surveillance of anti-malaria drug efficacy was used for the study with primary outcomes as prevalence of day 3 parasitaemia and clinical and parasitological cure rates on day 28. Secondary outcomes assessed included patterns of fever and parasite clearance as well as changes in haemoglobin concentration.ResultsDay 3 parasitaemia was absent in all sites following treatment with AS–AQ whilst only one person (0.2%) was parasitaemic on day 3 following treatment with AL. Day 28 PCR-corrected cure rates following treatment with AS–AQ ranged between 96.7% (95% CI 88.5–99.6) and 100%, yielding a national rate of 99.2% (95% CI 97.7–99.7). Day 28 PCR-corrected cure rates following treatment with AL ranged between 91.3% (95% CI 79.2–97.6) and 100%, yielding a national rate of 96% (95% CI 93.5–97.6). Prevalence of fever declined by 88.4 and 80.4% after first day of treatment with AS–AQ and AL, respectively, whilst prevalence of parasitaemia on day 2 was 2.1% for AS–AQ and 1.5% for AL. Gametocytaemia was maintained at low levels (< 5%) during the 3 days of treatment. Post-treatment mean haemoglobin concentration was significantly higher than pre-treatment concentration following treatment with either AS–AQ or AL.ConclusionsThe therapeutic efficacy of AS–AQ and AL is over 90% in sentinel sites across Ghana. The two anti-malarial drugs therefore remain efficacious in the treatment of uncomplicated malaria in the country and continue to achieve rapid fever and parasite clearance as well as low gametocyte carriage rates and improved post-treatment mean haemoglobin concentration.

Slow parasite clearance, absent K13-propeller gene polymorphisms and adequate artesunate levels among patients with malaria: A pilot study from southern India.

Artemisinin-based combination therapy (ACT) is widely used in India and many generic preparations are available. Delayed response has been reported, suggesting inadequate response to artesunate (AS) or genotypic resistance. We designed a prospective observational study to assess the therapeutic response, elaborate pharmacokinetics of AS and identify Plasmodium falciparum kelch 13 (pfk13) propeller gene polymorphisms among hospitalized Indian patients with severe malaria. We collected blood samples from adult patients with severe P. falciparum or mixed (P. falciparum and P. vivax) malaria on ACT. We calculated the parasite clearance (CL) half-life using the Worldwide Antimalarial Resistance Network (WWARN) online parasite clearance estimator (PCE). We used the liquid chromatography tandem mass spectrophoto-metry method for simultaneous quantification of AS and dihydroartemisinin. We genotyped longitudinally archived DNA samples obtained pre-treatment (day 0) to study the point mutations in the pfk13 propeller domain. A total of 54 patients with malaria were included, with a majority fulfilling the definitions of severe malaria. The median parasite CL slope half-life was estimated to be 6.44 hours (interquartile range 4.79-10.24). AS pharmacokinetics, assessed in 17 patients, were found to be similar in the groups with rapid (<48 hours) and slow CL (>48 hours) of parasites. No known mutations associated with artemisinin resistance in Southeast Asia were observed in our study participants. Slow parasite CL was seen with a high parasite burden without genotypic evidence of AS resistance. There is a need to standardize definitions of therapeutic efficacy of AS in cases of severe malaria.

Efficacy of artesunate\u2013amodiaquine in the treatment of falciparum uncomplicated malaria in Madagascar

BackgroundSince 2006, the artemisinin-based combination therapy (ACT) are recommended to treat uncomplicated malaria including non Plasmodium falciparum malaria in Madagascar. Artesunate–amodiaquine (ASAQ) and artemether–lumefantrine are the first- and second-line treatment in uncomplicated falciparum malaria, respectively. No clinical drug efficacy study has been published since 2009 to assess the efficacy of these two artemisinin-based combinations in Madagascar, although the incidence of malaria cases has increased from 2010 to 2016. In this context, new data about the efficacy of the drug combinations currently used to treat malaria are needed.MethodsTherapeutic efficacy studies evaluating the efficacy of ASAQ were conducted in 2012, 2013 and 2016 among falciparum malaria-infected patients aged between 6 months and 56 years, in health centres in 6 sites representing different epidemiological patterns. The 2009 World Health Organization protocol for monitoring anti-malarial drug efficacy was followed.ResultsA total of 348 enrolled patients met the inclusion criteria including 108 patients in 2012 (n = 64 for Matanga, n = 44 for Ampasipotsy), 123 patients in 2013 (n = 63 for Ankazomborona, n = 60 for Anjoma Ramartina) and 117 patients in 2016 (n = 67 for Tsaratanana, n = 50 for Antanimbary). The overall cumulative PCR-corrected day 28 cure rate was 99.70% (95% IC 98.30–99.95). No significant difference in cure rates was observed overtime: 99.02% (95% IC 94.65–99.83) in 2012; 100% (95% IC 96.8–100) in 2013 and 100% (95% IC 96.65–100) in 2016.ConclusionThe ASAQ combination remains highly effective for the treatment of uncomplicated falciparum malaria in Madagascar.

In vitro oxygen availability modulates the effect of artesunate on HeLa cells.

Hypoxia can affect chemotherapeutic drug efficacy in cancer patients, yet related in vitro assays in oxygen-rich environment remain the norm. Such levels are well beyond normoxic/hypoxic levels typically experienced by normal tissues/tumor masses. The present study evaluated how artesunate anti-tumor efficacy is modulated by oxygen availability in HeLa cells and its implications for future in vitro analyses. Real-time cell analysis was employed to evaluate HeLa cell toxicity to artesunate at 21%, 4% or 1% oxygen. Cell count analysis was performed to validate real-time data. An increase in artesunate efficacy was observed when oxygen concentration was reduced from atmospheric levels down to in vivo-relevant levels. Artesunate is more potent than originally reported using standard oxygen conditions during in vitro studies. The inclusion of this long overlooked variable as standard in future in vitro analysis procedures is warranted.

PF3D7_1343700 KELCH PROPELLER (K13-PROPELLER) POLYMORPHISMS AND ARTESUNATE MONOTHERAPY EFFICACY IN UNCOMPLICATED MALARIA TREATMENT IN MALI

BackgroundSeveral mutations in the PF3D7_1343700 kelch propeller (K13-propeller) were recently described as associated with artemisinin resistance in vivo and in vitro in Southeast Asia. In Mali, a preliminary study on...

Continued Sensitivity of Plasmodium falciparum to Artemisinin in Guyana, With Absence of Kelch Propeller Domain Mutant Alleles.

Because of concerns about possible emergence of artemisinin resistance strains of Plasmodium falciparum in mining areas of the interior of Guyana, a 7-day artesunate trial was conducted from March to December 2014. The day-3 parasite clearance rate, the efficacy of artesunate at day 28, and polymorphism of Kelch 13 (PfK13)—the marker of artemisinin resistance—were assessed. The study confirmed the continued sensitivity of P falciparum to artemisinin. A 7-day course of artesunate was 100% efficacious with only 2% (95% confidence interval, .1%–10.9%) of enrolled subjects positive at day 3. All day-0 parasite samples were wild type. Continued resistance monitoring is nevertheless recommended, given the widespread availability and uncontrolled use of artemisinin drugs in mining areas of Guyana.

In Vivo Efficacy and Parasite Clearance of Artesunate + Sulfadoxine-Pyrimethamine Versus Artemether-Lumefantrine in Mali.

Although artemisinin resistance has yet to be reported in Africa, surveillance of the efficacy of artemisinin-based combination therapies (ACTs) is warranted. Here, the efficacy of artesunate + sulfadoxine-pyrimethamine (AS + SP) and artemether-lumefantrine (AL) was evaluated in Mali. Randomized open-label comparative in vivo assay of AS + SP versus AL were carried out using the 28-day follow-up World Health Organization protocol. Patients with uncomplicated falciparum malaria and at least 6 months of age were recruited between October 2010 and January 2014. A subset of these patients was selected to measure Plasmodium falciparum clearance time. Polymerase chain reaction-corrected adequate clinical and parasitological responses were 100% for AS + SP and 98.2% for AL with no significant difference (P = 0.06). The reinfection rates were comparable (P = 0.63) with 8.0% for AS + SP and 12.6% for AL. Individuals under 8 years were more susceptible to treatment failure (relative risk = 1.9; 95% confidence interval = 1.2, 3.3). Median parasite clearance half-life was 1.7 hours (interquartile range [IQR] = 1.3-2.2) for AS + SP and 1.9 hours (IQR = 1.5-2.5) for AL with no statistically significant difference (P = 0.24). Efficacy of AS + SP and AL was high. This study provides baseline information on parasite clearance half-lives after ACT treatment, particularly AS + SP, in Mali.

Four years’ monitoring of in vitro sensitivity and candidate molecular markers of resistance of Plasmodium falciparum to artesunate-mefloquine combination in the Thai-Myanmar border

BackgroundThe decline in efficacy of artesunate (AS) and mefloquine (MQ) is now the major concern in areas along the Thai-Cambodian and Thai-Myanmar borders.MethodsThe correlation between polymorphisms of pfatp6, pfcrt, pfmdr1 and pfmrp1 genes and in vitro sensitivity of Plasmodium falciparum isolates to the artemisinin-based combination therapy (ACT) components AS and MQ, including the previously used first-line anti-malarial drugs chloroquine (CQ) and quinine (QN) were investigated in a total of 119 P. falciparum isolates collected from patients with uncomplicated P. falciparum infection during 2006–2009.ResultsReduced in vitro parasite sensitivity to AS [median (95% CI) IC50 3.4 (3.1-3.7) nM] was found in 42% of the isolates, whereas resistance to MQ [median (95% CI) IC50 54.1 (46.8-61.4) nM] accounted for 58% of the isolates. Amplification of pfmdr1 gene was strongly associated with a decline in susceptibility of P. falciparum isolates to AS, MQ and QN. Significant difference in IC50 values of AS, MQ and QN was observed among isolates carrying one, two, three, and ≥ four gene copies [median (95% CI) AS IC50: 1.6 (1.3-1.9), 1.8 (1.1-2.5), 2.9 (2.1-3.7) and 3.1 (2.5-3.7) nM, respectively; MQ IC50: 19.2 (15.8-22.6), 37.8 (10.7-64.8), 55.3 (47.7-62.9) and 63.6 (49.2-78.0) nM, respectively; and QN IC50: 183.0 (139.9-226.4), 256.4 (83.7-249.1), 329.5 (206.6-425.5) and 420.0 (475.2-475.6) nM, respectively]. The prevalence of isolates which were resistant to QN was reduced from 21.4% during the period 2006–2007 to 6.3% during the period 2008–2009. Pfmdr1 86Y was found to be associated with increased susceptibility of the parasite to MQ and QN. Pfmdr1 1034C was associated with decreased susceptibility to QN. Pfmrp1 191Y and 1390I were associated with increased susceptibility to CQ and QN, respectively.ConclusionHigh prevalence of CQ and MQ-resistant P. falciparum isolates was observed during the four-year observation period (2006–2009). AS sensitivity was declined, while QN sensitivity was improved. Pfmdr1 and pfmrp1 appear to be the key genes that modulate multidrug resistance in P. falciparum.

The Efficacy of Artesunate, Chloroquine, Doxycycline, Primaquine and a Combination of Artesunate and Primaquine against Avian Malaria in Broilers

ABSTRACTThe efficacy of 5 antimalarial drugs was evaluated on P. gallinaceum infected broilers. One hundred and forty-seven 19-day-old broilers were divided into 7 groups of 21 chicks each. Group 1 was the unmedicated, uninfected control. Groups 2–6 were infected and medicated with artesunate, chloroquine, doxycycline, primaquine and an artesunate-primaquine combination, respectively. Group 7 was the unmedicated, infected control. Infectivity, mortality, parasitemia, schizonts in tissues and body weight gain were monitored. The results revealed that the two most effective drugs for treating P. gallinaceum at the asexual erythrocyte stage were chloroquine and doxycycline. Tissue schizonts of P. gallinaceum in all the medicated groups were significantly fewer than the unmedicated, infected control (P<0.05). The mortality rate of all the medicated groups was significantly lower than the unmedicated, infected control (P<0.05).