Artemisinin-based Combination Therapy Research Articles

Quality of Oral Drug Formulations of Artemisinin-Based Combination Therapy Sold in Katsina State, Nigeria

There are increasing reports of substandard antimalarial drugs, and these have been a severe under-recognised public health problem especially in developing countries. For this reason, 21 samples of different brands of artemisinin-based combination therapies (ACTs) comprising of artemether/lumefantrine and artesunate/amodiaquine oral drug formulations that are available on sale in different hospital pharmacies and patent medicine stores in Katsina State, Nigeria were evaluated for microbial and chemical qualities. Microbial limit test (MLT) and assay for the content of the active pharmaceutical ingredients (APIs) using standard high performance liquid chromatography (HPLC) procedures were carried out as described in the official monograph of the United States Pharmacopoeia (USP) and the International Pharmacopoeia (IP). The results obtained had indicated that all the ACTs oral drug preparations were free from microbial contamination except one sample of artesunate-amodiaquine showing viable total combined yeasts/moulds count (TYMC) of 1.0 x 101 colony forming units (CFU)/g. All the samples complied with the USP and IP criteria for the microbiological quality of non-sterile oral dosage forms. On the other hand, 10 (47.6%) out of the 21 samples met the specific chemical quality standards. Moreover, 8 (57.1%) and 3 (42.9%) of the artemether/lumefantrine and artesunate/amodiaquine had active ingredient outside the set pharmacopoeial limit and, therefore, were none compliant to the IP specifications for percentage content. The presence of substandard ACTs may lead to possible therapeutic failure from the use of such kind of formulations, facilitate the development and spread of drug-resistance. There is the need for effective government regulation and adequate enforcement on the production, distribution and sales of good quality medicines.

Plasmodium falciparum Drug Resistance Genes pfmdr1 and pfcrt In Vivo Co-Expression During Artemether-Lumefantrine Therapy.

Background: Artemisinin-based combination therapies (ACTs) are the global mainstay treatment of uncomplicated Plasmodium falciparum infections. PfMDR1 and PfCRT are two transmembrane transporters, associated with sensitivity to several antimalarials, found in the parasite food vacuole. Herein, we explore if their relatedness extends to overlapping patterns of gene transcriptional activity before and during ACT administration. Methods: In a clinical trial performed in Tanzania, we explored the pfmdr1 and pfcrt transcription levels from 48 patients with uncomplicated P. falciparum malaria infections who underwent treatment with artemether-lumefantrine (AL). Samples analyzed were collected before treatment initiation and during the first 24 h of treatment. The frequency of PfMDR1 N86Y and PfCRT K76T was determined through PCR-RFLP or direct amplicon sequencing. Gene expression was analyzed by real-time quantitative PCR. Results: A wide range of pre-treatment expression levels was observed for both genes, approximately 10-fold for pfcrt and 50-fold for pfmdr1. In addition, a significant positive correlation demonstrates pfmdr1 and pfcrt co-expression. After AL treatment initiation, pfmdr1 and pfcrt maintained the positive co-expression correlation, with mild downregulation throughout the 24 h post-treatment. Additionally, a trend was observed for PfMDR1 N86 alleles and higher expression before treatment initiation. Conclusion: pfmdr1 and pfcrt showed significant co-expression patterns in vivo, which were generally maintained during ACT treatment. This observation points to relevant related roles in the normal parasite physiology, which seem essential to be maintained when the parasite is exposed to drug stress. In addition, keeping the simultaneous expression of both transporters might be advantageous for responding to the drug action.

Artemisinin-based antimalarial combination therapy amongst healthcare professionals in a tertiary facility in south-south Nigeria: preferences, tolerability, and cost considerations

Background: Nigeria adopted the Artemisinin-Based Combination Therapy (ACT) as the mainstay of treating uncomplicated malaria in February 2005. However, the individual preferences for the use of these medicines by health care professionals (HCP) as distinct from their observed prescribing practices is largely unknown. This study determined the preferences, tolerability and cost of the ACTs among HCPin Benin-City.Methods: This descriptive cross-sectional study was conducted in the University of Benin Teaching Hospital, Benin-City, Nigeria. Consenting HCPs were recruited consecutively for the study. Semistructured questionnaires were administered to doctors, nurses and pharmacists in the hospital. Information obtained included demographics, treatment of malaria in the previous year, antimalarial medication preferences and tolerability as well as cost of ACT.Results: A total of 556 HCPs, 295 doctors (54.1%), nurses 200 (36.0%), pharmacists 61(11.0%) completed the questionnaire. In the previous year, 224 (75.9%) doctors, 153 (79.1%) nurses, and 48 (70.5%) pharmacists had treatment for malaria and self-medication was highest among doctors (228, 77.3%). Artemether-Lumenfantrine was the most preferred antimalarial used, 294 (52.8%); however, 1.6% used chloroquine sulphate and ACTs were perceived to be ineffective by 25.4%. Adverse effects were experienced by 167 (29.1%) resulting in 50 (9.0%) discontinuing their medication. Between 500 and 1500 Naira (~US$1-4) was expended on ACT by 66.3% of the staff, while 21.4% were concerned about the high cost of medications.Conclusion: This study highlights the use and preferences, self-medication practices, perceived lack of effectiveness and high cost of ACTs from a HCP perspective. There is an urgent need to address these concerns in view of adverse consequences as well as the likely possibility of its the impact on prescribingpractices.

Novel pfk13 polymorphisms in Plasmodium falciparum population in Ghana

The molecular determinants of Plasmodium falciparum artemisinin resistance are the single nucleotide polymorphisms in the parasite’s kelch propeller domain, pfk13. Validated and candidate markers are under surveillance in malaria endemic countries using artemisinin-based combination therapy. However, pfk13 mutations which may confer parasite artemisinin resistance in Africa remains elusive. It has therefore become imperative to report all observed pfk13 gene polymorphisms in malaria therapeutic efficacy studies for functional characterization. We herein report all novel pfk13 mutations observed only in the Ghanaian parasite population. In all, 977 archived samples from children aged 12 years and below with uncomplicated malaria from 2007 to 2017 were used. PCR/Sanger sequencing analysis revealed 78% (763/977) of the samples analyzed were wild type (WT) for pfk13 gene. Of the 214 (22%) mutants, 78 were novel mutations observed only in Ghana. The novel SNPs include R404G, P413H, N458D/H/I, C473W/S, R529I, M579T/Y, C580R/V, D584L, N585H/I, Q661G/L. Some of the mutations were sites and ecological zones specific. There was low nucleotide diversity and purifying selection at the pfk13 locus in Ghanaian parasite population. With increasing drug pressure and its consequent parasite resistance, documenting these mutations as baseline data is crucial for future molecular surveillance of P. falciparum resistance to artemisinin in Ghana.

Biotechnological Approaches for Production of Artemisinin, an Anti-Malarial Drug from Artemisia annua L.

Artemisinin is an anti-malarial sesquiterpene lactone derived from Artemisia annua L. (Asteraceae family). One of the most widely used modes of treatment for malaria is an artemisinin-based combination therapy. Artemisinin and its associated compounds have a variety of pharmacological qualities that have helped achieve economic prominence in recent years. So far, research on the biosynthesis of this bioactive metabolite has revealed that it is produced in glandular trichomes and that the genes responsible for its production must be overexpressed in order to meet demand. Using biotechnological applications such as tissue culture, genetic engineering, and bioreactor-based approaches would aid in the upregulation of artemisinin yield, which is needed for the future. The current review focuses on the tissue culture aspects of propagation of A. annua and production of artemisinin from A. annua L. cell and organ cultures. The review also focuses on elicitation strategies in cell and organ cultures, as well as artemisinin biosynthesis and metabolic engineering of biosynthetic genes in Artemisia and plant model systems.

India Needs to Consider Planning a Change to Artemether-Lumefantrine to Treat Plasmodium falciparum Malaria.

As the malaria elimination target draws closer for India, it must be ensured that the country's policies, strategies, and tools remain effective. Artemisinin-based combination therapies are the mainstay of Plasmodium falciparum malaria management. India has a differential standard therapy for uncomplicated falciparum malaria in the form of artemether-lumefantrine in its northeastern states and artesunate + sulfadoxine-pyrimethamine in the rest of the country. The clinical failure of artesunate + sulfadoxine-pyrimethamine in the northeast regions were attributed primarily to parasite resistance resulting from mutations in the enzymes dihydropteroate synthase and dihydrofolate reductase. Artemether-lumefantrine was therefore substituted for artesunate + sulfadoxine-pyrimethamine in the region. The change has been a success, as evidenced by the therapeutic efficacy studies conducted at regular intervals in India. However, studies suggest that resistance may be emerging toward sulfadoxine-pyrimethamine in multiple parts of the nation. Hence, there is a possibility that the artesunate + sulfadoxine-pyrimethamine combination may be acting in part as a monotherapy, and this makes the longevity of the artesunate + sulfadoxine-pyrimethamine drug combination therapy uncertain. The increasing presence of drug-resistant mutants in P. falciparum dhps and dhfr genes suggests the need for a policy switch for uncomplicated P. falciparum malaria from artesunate + sulfadoxine-pyrimethamine to artemether-lumefantrine.

In silico evaluation of inhibitors of Plasmodium falciparumAP2‐I transcription factor

Recent treatment failures observed for Artemisinin‐based combination therapy (ACT) have raised concerns about the efficacy of the front‐line drug to treat malaria and the need to develop a new antimalarial drug regimen. Plasmodium falciparum Apicomplexan Apetala 2 Invasion (PfAP2‐I) transcription factor (TF) is a protein that regulates the expression of a subset of gene families involved in Plasmodium falciparum red blood cell (RBC) invasion. Inhibiting PfAP2‐I TF with small molecules represents a potential new antimalarial therapeutic target to combat drug resistance, which is the aim of this study. The 3D model structure of PfAP2‐I was predicted ab initio using ITASSER and ROBETTA prediction tools and was validated using Errat and Procheck from the Save server 6.0. Computed Atlas of Surface Topography of proteins (CASTp) 3.0 and ConCavity were used to predict the active sites of the PfAP2‐I 3D7 modeled structure. Pharmacophore modeling of the control ligand (3W7 from COACH server) and modeled 3D structure of PfAP2‐I was carried out using the Pharmit server to obtain several compounds for docking analysis. Chimera software was used to remove the complexed ligands, and the modeled protein structure was defined as a receptor. Virtual screening and post‐screening studies were conducted using AutoDock vina and LigPlot. The designed ligands’ toxicity predictions and in silico drug‐likeness were performed using the Swiss ADME predictor and OSIRIS Property Explorer. The modeled protein from the ROBETTA prediction tool was prioritized based on structure validation results of 96.827 for ERRAT and 90.2% of the amino acid residues in the most favored region for the Ramachandran plot. A total of 8656 compounds obtained from six (6) databases on the Pharmit server were used to prepare the ligand library and screened against the prepared 3D model structure of PfAP2‐I, considering the active sites predicted from CASTp and ConCavity. Six (6) best hits were selected based on the binding affinity to the active site PfAP2‐I and were considered for post‐screening analyses. The six compounds exhibited dock score values (between ‐9.9 to ‐10.2 kcal/mol), having lower binding energies than the standard drug ‐ Chloroquine (‐5.10 kcal/mol). The best dock score was compound ZINC97139187 (‐10.2 kcal/mol). For the ADMET properties, compound ZINC97139187 had the highest drug score of 0.63, followed by compound 154861216 with a drug score of 0.58 (both higher than that of the standard drug ‐ chloroquine of 0.25). The good, estimated binding energies and drug score values observed for compound ZINC97139187 and compound 154861216 suggest that they can be considered possible PfAP2‐I inhibitors. Further pre‐clinical experimental validations should be carried out to ascertain the efficacy of these predicted best hits.

Expert perspectives on the introduction of Triple Artemisinin-based Combination Therapies (TACTs) in Southeast Asia: a Delphi study

BackgroundTriple Artemisinin-based Combination Therapies (TACTs) are being developed as a response to artemisinin and partner drug resistance in Southeast Asia. However, the desirability, timing and practical feasibility of introducing TACTs in Southeast Asia is subject to debate. This study systematically assesses perspectives of malaria experts towards the introduction of TACTs as first-line treatment for uncomplicated falciparum malaria in Southeast Asia.MethodsA two-round Delphi study was conducted. In the first round, 53 malaria experts answered open-ended questions on what they consider the most important advantages, disadvantages, and implementation barriers for introducing TACTs in Southeast Asia. In the second round, the expert panel rated the relevance of each statement on a 5-point Likert scale.ResultsMalaria experts identified 15 advantages, 15 disadvantages and 13 implementation barriers for introducing TACTs in Southeast Asia in the first round of data collection. In the second round, consensus was reached on 13 advantages (8 perceived as relevant, 5 as not-relevant), 12 disadvantages (10 relevant, 2 not-relevant), and 13 implementation barriers (all relevant). Advantages attributed highest relevance related to the clinical and epidemiological rationale of introducing TACTs. Disadvantages attributed highest relevance related to increased side-effects, unavailability of fixed-dose TACTs, and potential cost increases. Implementation barriers attributed highest relevance related to obtaining timely regulatory approval, timely availability of fixed-dose TACTs, and generating global policy support for introducing TACTs.ConclusionsThe study provides a structured oversight of malaria experts’ perceptions on the major advantages, disadvantages and implementation challenges for introducing TACTs in Southeast Asia, over current practices of rotating ACTs when treatment failure is observed. The findings can benefit strategic decision making in the battle against drug-resistant malaria.

Effect of Combination Songga-Wood-Stem (Strychnos ligustrina Blume) and Antimalaria-ACT on IL-10 Production of Malaria

Malaria is one of the deadliest infectious diseases in the world. Artemisinin-Based-Combination-Therapy (ACT) an antimalaria recommended by WHO, is starting to experience resistance in Asia. Meanwhile the natural-product-immunoprotective and antimalaria-effect may benefice for malaria. Objective of this study was to determine the effect of combination of ethanolic-extract from Songga-wood-stem (EESWS) and ACT on IL-10, a protective-cytokine against malaria-immunopathology. This experimental-study used post-test-only-randomized-controlled-group-design. The thirty-Swiss-webster-mice were grouped into 5 groups. The one-group of healthy-mice (K1), and the four-groups infected with Plasmodium berghei ANKA (PbA) which were untreated-K2-group, ACT-treated-K3-group, EESWS-treated-P1-group, and EESWS-ACT-combination-treated-P2-group. IL-10-level of stimulated-splenocytes-culture was examined by ELISA-method. Data-analysis-used was One-Way-Anova-Welch-test and Post-hoc Games-Howell. P1 and P2-groups had higher IL-10-levels than K1 (p=0.038). Groups of P1 and P2 showed lower IL-10-levels than K3 (p=0.001). IL-10-level of P2-group was not different than P1 (p=0.135). The conclusion is the EEWS or EESWS-ACT-combination-therapy restrains the increase-splenic-IL-10-production above normal value in the healing phase of malaria infection.

The antimalarial activity of 1,2,4-trioxolane/trioxane hybrids and dimers: A review.

Malaria, a mosquito-borne parasitic infection caused by protozoan parasites belonging to the genus Plasmodium, is a dangerous disease that contributes to millions of hospital visits and hundreds and thousands of deaths across the world, especially in Sub-Saharan Africa. Antimalarial agents are vital for treating malaria and controlling transmission, and 1,2,4-trioxolane/trioxane-containing agents, especially artemisinin and its derivatives, own antimalarial efficacy and low toxicity with unique mechanisms of action. Moreover, artemisinin-based combination therapies were recommended by the World Health Organization as the first-line treatment for uncomplicated malaria infection and have remained as the mainstay of the treatment of malaria, demonstrating that 1,2,4-trioxolane/trioxane derivatives are useful prototypes for the control and eradication of malaria. However, malaria parasites have already developed resistance to almost all of the currently available antimalarial agents, creating an urgent need for the search of novel pharmaceutical interventions for malaria. The purpose of this review article is to provide an emphasis on the current scenario (January 2012 to January 2022) of 1,2,4-trioxolane/trioxane hybrids and dimers with potential antimalarial activity and the structure-activity relationships are also discussed to facilitate further rational design of more effective candidates.

The Effect of Arthrospira Platensis on the Acute Toxicity of Artemeter Lumefantrine in Malaria Patients

Malaria has remained one of the leading causes of morbidity and mortality in most developing countries. This pathology is caused by the Plasmodium spp. Artemisinin-based combination therapy is recommended by current WHO guidelines for the treatment of uncomplicated falciparum malaria (ACT). -Linolenic acid, one of the necessary fatty acids, is abundant in the microscopic filamentous alga Arthrospira platensis, which is rich in proteins, vitamins, vital amino acids, and minerals (GLA). The current study was carried out to evaluate the effect of Arthrospira platensis on the liver and kidney toxicity induced by ACT. Malaria patients were randomized into two groups to receive therapeutic dose of either artemether-lumefantrine 20/120mg (group 1) or artemether-lumefantrine 20/120mg + Arthrospira platensis 8g daily (group2) as an adjunct therapy and follow-up for 7 days. After treatment their liver and kidney Biochemical parameters (ALT, AST, ALB, UREA, CREAT) were measured. Both pre and post treatment samples were analyzed and the results gotten compared with control group made up of malaria negative patients. Serum activity of selected biomarkers (ALT, AST, ALB, UREA) of malaria patients were seen to be statistically significant (P<0.05) on D0 when compared to that of malaria negative patients. This study showed that Arthrospira platensis prevented the artemether-lumefantrine induced significant changes on the liver and kidney biochemical parameters analyzed. The results obtained from this study, indicate that Arthrospira platensis has a positive effect on the liver and kidney toxicity induced by ACT and hence could be administered together with ACT in malaria treatment. Keywords: Malaria, ACT, Toxicity, Arthrospira platensis, oxidative damage

Effectiveness of Artemether Lumefantrine and Dihydroartemisinin Piperaquine in Clearance of Gametocytes in Uncomplicated Plasmodium falciparum Malaria in Tiwi Kenya

Background: Over 80 countries worldwide have now implemented WHO recommendations to use Artemisinin-Based Combination Therapy as a first-line treatment for Plasmodium falciparum malaria. The sexual stage of P. falciparum is responsible for the transmission of malarial parasites to infectious mosquitoes. Studies on gametocytes are generally based on microscopic detection, which is not sensitive, and there is a need for more sensitive molecular techniques that can detect and quantify gametocytes at densities as low as 0.02 to 0.1 gametocytes per micro-litre. The objective of this study was to determine the clearance rates of gametocytes after AL and DHA&P in uncomplicated P. falciparum and to compare the effectiveness of microscopy and reverse transcriptase-polymerase chain reaction in gametocyte detection. Methods: In a randomised controlled clinical trial of samples collected, gametocyte densities were quantified by microscopy by counting against 500 leukocytes in the thick smear converted to numbers of parasites per micro-litre by assuming a standard count of 800 leukocytes per micro-litre of blood after staining with 10% Giemsa stain and by reverse transcriptase-polymerase chain reaction using primers specific to the pfs25 gene. Results: There was no significant difference between the drug’s gametocyte clearance (p<.082). The drugs cleared gametocytes in infected patients by day 28 as detected by microscopy. There was a significant difference in the detection of gametocytes by RT-PCR and microscopy (p<.001). Conclusion: This study showed that Artemether-Lumefantrine and Dihydroartemisinin piperaquine have gametocytocidal effects on P. falciparum and the study on the clearance of gametocytes using both artemether-lumefantrine and Dihydroartemisinin piperaquine may be carried out using a larger sample size for policy implementation. The reverse transcriptase-polymerase chain reaction is more effective than microscopy in detecting low levels of gametocytes and the pfs25 gene can be used in the detection of gametocytes in the field to monitor the clearance of gametocytes.

Temporal distribution of Plasmodium falciparum recrudescence following artemisinin-based combination therapy: an individual participant data meta-analysis

BackgroundThe duration of trial follow-up affects the ability to detect recrudescent infections following anti-malarial treatment. The aim of this study was to explore the proportions of recrudescent parasitaemia as ascribed by genotyping captured at various follow-up time-points in treatment efficacy trials for uncomplicated Plasmodium falciparum malaria.MethodsIndividual patient data from 83 anti-malarial efficacy studies collated in the WorldWide Antimalarial Resistance Network (WWARN) repository with at least 28 days follow-up were available. The temporal and cumulative distributions of recrudescence were characterized using a Cox regression model with shared frailty on study-sites. Fractional polynomials were used to capture non-linear instantaneous hazard. The area under the density curve (AUC) of the constructed distribution was used to estimate the optimal follow-up period for capturing a P. falciparum malaria recrudescence. Simulation studies were conducted based on the constructed distributions to quantify the absolute overestimation in efficacy due to sub-optimal follow-up.ResultsOverall, 3703 recurrent infections were detected in 60 studies conducted in Africa (15,512 children aged < 5 years) and 23 studies conducted in Asia and South America (5272 patients of all ages). Using molecular genotyping, 519 (14.0%) recurrences were ascribed as recrudescent infections. A 28 day artemether-lumefantrine (AL) efficacy trial would not have detected 58% [95% confidence interval (CI) 47–74%] of recrudescences in African children and 32% [95% CI 15–45%] in patients of all ages in Asia/South America. The corresponding estimate following a 42 day dihydroartemisinin-piperaquine (DP) efficacy trial in Africa was 47% [95% CI 19–90%] in children under 5 years old treated with > 48 mg/kg total piperaquine (PIP) dose and 9% [95% CI 0–22%] in those treated with ≤ 48 mg/kg PIP dose. In absolute terms, the simulation study found that trials limited to 28 days follow-up following AL underestimated the risk of recrudescence by a median of 2.8 percentage points compared to day 63 estimates and those limited to 42 days following DP underestimated the risk of recrudescence by a median of 2.0 percentage points compared to day 42 estimates. The analysis was limited by few clinical trials following patients for longer than 42 days (9 out of 83 trials) and the imprecision of PCR genotyping which overcalls recrudescence in areas of higher transmission biasing the later distribution.ConclusionsRestricting follow-up of clinical efficacy trials to day 28 for AL and day 42 for DP will miss a proportion of late recrudescent treatment failures but will have a modest impact in derived efficacy. The results highlight that as genotyping methods improve consideration should be given for trials with longer duration of follow-up to detect early indications of emerging drug resistance.

Molecular surveillance for operationally relevant genetic polymorphisms in Plasmodium falciparum in Southern Chad, 2016\u20132017

BackgroundResistance to anti-malarials is a serious threat to the efforts to control and eliminate malaria. Surveillance based on simple field protocols with centralized testing to detect molecular markers associated with anti-malarial drug resistance can be used to identify locations where further investigations are needed.MethodsDried blood spots were collected from 398 patients (age range 5–59 years, 99% male) with Plasmodium falciparum infections detected using rapid diagnostic tests over two rounds of sample collection conducted in 2016 and 2017 in Komé, South-West Chad. Specimens were genotyped using amplicon sequencing or qPCR for validated markers of anti-malarial resistance including partner drugs used in artemisinin-based combination therapy (ACT).ResultsNo mutations in the pfk13 gene known to be associated with artemisinin resistance were found but a high proportion of parasites carried other mutations, specifically K189T (190/349, 54.4%, 95%CI 49.0–59.8%). Of 331 specimens successfully genotyped for pfmdr1 and pfcrt, 52% (95%CI 46.4–57.5%) carried the NFD-K haplotype, known to be associated with reduced susceptibility to lumefantrine. Only 20 of 336 (6.0%, 95%CI 3.7–9.0%) had parasites with the pfmdr1-N86Y polymorphism associated with increased treatment failures with amodiaquine. Nearly all parasites carried at least one mutation in pfdhfr and/or pfdhps genes but ‘sextuple’ mutations in pfdhfr—pfdhps including pfdhps -A581G were rare (8/336 overall, 2.4%, 95%CI 1.2–4.6%). Only one specimen containing parasites with pfmdr1 gene amplification was detected.ConclusionsThese results provide information on the likely high efficacy of artemisinin-based combinations commonly used in Chad, but suggest decreasing levels of sensitivity to lumefantrine and high levels of resistance to sulfadoxine-pyrimethamine used for seasonal malaria chemoprevention and intermittent preventive therapy in pregnancy. A majority of parasites had mutations in the pfk13 gene, none of which are known to be associated with artemisinin resistance. A therapeutic efficacy study needs to be conducted to confirm the efficacy of artemether-lumefantrine.

Therapeutic efficacy of artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine in the treatment of uncomplicated Plasmodium falciparum malaria in Sub-Saharan Africa: A systematic review and meta-analysis.

Sub-Saharan Africa has the highest burden of malaria in the world. Artemisinin-based combination therapies (ACTs) have been the cornerstone in the efforts to reduce the global burden of malaria. In the effort to facilitate early detection of resistance for artemisinin derivatives and partner drugs, WHO recommends monitoring of ACT's efficacy in the malaria endemic countries. The present systematic meta-analysis study summarises the evidence of therapeutic efficacy of the commonly used artemisinin-based combinations for the treatment of uncomplicated P. falciparum malaria in Sub-Saharan Africa after more than a decade since the introduction of the drugs. Fifty two studies carried out from 2010 to 2020 on the efficacy of artemether-lumefantrine or dihydro-artemisinin piperaquine or artesunate amodiaquine in patients with uncomplicated P. falciparum malaria in Sub-Saharan Africa were searched for using the Google Scholar, Cochrane Central Register of controlled trials (CENTRAL), PubMed, Medline, LILACS, and EMBASE online data bases. Data was extracted by two independent reviewers. Random analysis effect was performed in STATA 13. Heterogeneity was established using I2 statistics. Based on per protocol analysis, unadjusted cure rates in malaria infected patients treated with artemether-lumefantrine (ALU), artesunate-amodiaquine (ASAQ) and dihydroartemisinin-piperaquine (DHP) were 89%, 94% and 91% respectively. However, the cure rates after PCR correction were 98% for ALU, 99% for ASAQ and 99% for DHP. The present meta-analysis reports the overall high malaria treatment success for artemether-lumefantrine, artesunate-amodiaquine and dihydroartemisinin-piperaquine above the WHO threshold value in Sub-Saharan Africa.

Synthesis, Antiplasmodial, and Antileukemia Activity of Dihydroartemisinin-HDAC Inhibitor Hybrids as Multitarget Drugs.

Artemisinin-based combination therapies (ACTs) are the gold standard for the treatment of malaria, but the efficacy is threatened by the development of parasite resistance. Histone deacetylase inhibitors (HDACis) are an emerging new class of potential antiplasmodial drugs. In this work, we present the design, synthesis, and biological evaluation of a mini library of dihydroartemisinin–HDACi hybrid molecules. The screening of the hybrid molecules for their activity against selected human HDAC isoforms, asexual blood stage P. falciparum parasites, and a panel of leukemia cell lines delivered important structure–activity relationships. All synthesized compounds demonstrated potent activity against the 3D7 and Dd2 line of P. falciparum with IC50 values in the single-digit nanomolar range. Furthermore, the hybrid (α)-7c displayed improved activity against artemisinin-resistant parasites compared to dihydroartemisinin. The screening of the compounds against five cell lines from different leukemia entities revealed that all hydroxamate-based hybrids (7a–e) and the ortho-aminoanilide 8 exceeded the antiproliferative activity of dihydroartemisinin in four out of five cell lines. Taken together, this series of hybrid molecules represents an excellent starting point toward the development of antimalarial and antileukemia drug leads.

Triple therapy with artemether–lumefantrine plus amodiaquine versus artemether–lumefantrine alone for artemisinin-resistant, uncomplicated falciparum malaria: an open-label, randomised, multicentre trial

SummaryBackgroundLate treatment failures after artemisinin-based combination therapies (ACTs) for falciparum malaria have increased in the Greater Mekong subregion in southeast Asia. Addition of amodiaquine to artemether–lumefantrine could provide an efficacious treatment for multidrug-resistant infections.MethodsWe conducted an open-label, randomised trial at five hospitals or health centres in three locations (western Cambodia, eastern Cambodia, and Vietnam). Eligible participants were male and female patients aged 2–65 years with uncomplicated Plasmodium falciparum malaria. Patients were randomly allocated (1:1 in blocks of eight to 12) to either artemether–lumefantrine alone (dosed according to WHO guidelines) or artemether–lumefantrine plus amodiaquine (10 mg base per kg/day), both given orally as six doses over 3 days. All received a single dose of primaquine (0·25 mg/kg) 24 h after the start of study treatment to limit transmission of the parasite. Parasites were genotyped, identifying artemisinin resistance. The primary outcome was Kaplan-Meier 42-day PCR-corrected efficacy against recrudescence of the original parasite, assessed by intent-to-treat. Safety was a secondary outcome. This completed trial is registered at ClinicalTrials.gov (NCT03355664).FindingsBetween March 18, 2018, and Jan 30, 2020, 310 patients received randomly allocated treatment; 154 received artemether–lumefantrine alone and 156 received artemether–lumefantrine plus amodiaquine. Parasites from 305 of these patients were genotyped. 42-day PCR-corrected treatment efficacy was noted in 151 (97%, 95% CI 92–99) of 156 patients with artemether–lumefantrine plus amodiaquine versus 146 (95%, 89–97) of 154 patients with artemether–lumefantrine alone; hazard ratio (HR) for recrudescence 0·6 (95% CI 0·2–1·9, p=0·38). Of the 13 recrudescences, 12 were in 174 (57%) of 305 infections with pfkelch13 mutations indicating artemisinin resistance, for which 42-day efficacy was noted in 89 (96%) of 93 infections with artemether–lumefantrine plus amodiaquine versus 73 (90%) of 81 infections with artemether–lumefantrine alone; HR for recrudescence 0·44 (95% CI 0·14–1·40, p=0·17). Artemether–lumefantrine plus amodiaquine was generally well tolerated, but the number of mild (grade 1–2) adverse events, mainly gastrointestinal, was greater in this group compared with artemether–lumefantrine alone (vomiting, 12 [8%] with artemether–lumefantrine plus amodiaquine vs three [2%] with artemether–lumefantrine alone, p=0·03; and nausea, 11 [7%] with artemether–lumefantrine plus amodiaquine vs three [2%] with artemether–lumefantrine alone, p=0·05). Early vomiting within 1 h of treatment, requiring retreatment, occurred in no patients of 154 with artemether–lumefantrine alone versus five (3%) of 156 with artemether–lumefantrine plus amodiaquine, p=0·06. Bradycardia (≤54 beats/min) of any grade was noted in 59 (38%) of 154 patients with artemether–lumefantrine alone and 95 (61%) of 156 with artemether–lumefantrine plus amodiaquine, p=0·0001.InterpretationArtemether–lumefantrine plus amodiaquine provides an alternative to artemether–lumefantrine alone as first-line treatment for multidrug-resistant P falciparum malaria in the Greater Mekong subregion, and could prolong the therapeutic lifetime of artemether–lumefantrine in malaria-endemic populations.FundingBill & Melinda Gates Foundation, Wellcome Trust.

Triple artemisinin-based combination therapies for malaria: a timely solution to counter antimalarial drug resistance

Drug resistance against antimalarials is inevitable, usually emerging slowly for approximately 20 years after they start being widely used, at which point there is a sudden onset of widespread resistance.1 This pattern has been seen for chloroquine, sulfadoxine-pyrimethamine, and most recently the components of artemisinin-based combination therapy (ACT), emphasising the need for a robust antimalarial drug pipeline featuring compounds with novel modes of action until global malaria eradication is achieved.

Preparation and Characterization of Advanced Nano medicine For Malaria: Box Behnken Design Approach

In tropical countries, malaria is a larger cause of sickness and death in adults and children. Drug resistance with antimalarial therapy has now become a serious problem worldwide and it is the basic reason for the need of combination therapy. Artemisinin-based combination therapy (ACT) is widely used nowadays. The drugs selected for the study from ACT were an Artesunate (AST) and Lumefantrine (LUM). In this study, the optimized Solid-Self nanoemulsifying drug delivery system (S-SNEDDS) formulation of AST and LUM was developed using Box Behnken design (BBD) which showed greater in-vitro drug release when compared to marketed formulation. Both the drugs AST and LUM show high solubility in Anise oil, Tween 80 (surfactant), and PEG 400 (co-surfactant). Ternary phase diagrams were used to select nanoemulsifying regions. It was found to have a maximum nanoemulsion region with a 2:1 surfactant to co-surfactant ratio. The effect of formulation variables was studied by BBD. Thirteen formulations were prepared and were further characterized based on globule size, PDI, zeta potential, self-emulsification time, cloud point, % transmittance and in vitro dissolution profiles. The optimized Liquid-SNEDDS (L-SNEDDS) with RHLB 13.76 gives globule size (82.8 nm), % T (96.7 %), in vitro release of AST (98.4 %) and LUM (97.07%) at 45 min. was converted into S-SNEDDS by using neusilin US2 as an adsorbent. The S-SNEDDS was characterized by SEM, globule size (98.24 nm), % T (95.02 %), in vitro release of ART (95.18 %) and LUM (96.4%) at 45 min. DSC and FTIR study for S-SNEDDS assure that there was an absence of any chemical interaction within the drug and carrier. SEM, X-ray diffraction studies confirmed that drugs exist in amorphous nature. The present research successfully developed S-SNEDDS for bioavailability enhancement of AST and LUM in fix dose combination&#x0D;

Development and Validation of an Ion-Pair HPLC-UV Method for the Quantitation of Quinoline and Indoloquinoline Alkaloids in Herbal and Pharmaceutical Antimalarial Formulations

Quinine- and cryptolepine-based antimalarials serve as valuable alternatives to artemisinin-based combination therapies (ACTs) in Ghana. Their use, however, is associated with adulteration and substandard quality challenges. An HPLC method targeting quinoline and indoloquinoline antimalarial alkaloids was developed, validated, and applied to evaluate herbal and pharmaceutical antimalarial formulations (HPAFs) and starting materials (APIs). The separation/quantitation of the alkaloids (including quinine, quinidine, cinchonine, cinchonidine, dihydroquinine, dihydroquinidine, and cryptolepine) was achieved on a Zorbax SB-CN column (250 mm × 4.6 mm, 5 μm), with an isocratic elution system of methanol: trifluoroacetic acid (0.1%, v/v) (15 : 85, v/v) at 1.5 mL/min and 223 nm. Method validation was according to ICH Q2(R1) guidelines. It was then used to assess the quality of APIs (n = 3) and HPAFs (n = 44) including quinine-based pharmaceutical antimalarial formulations (QBPAFs) (n = 23) and herbal antimalarial products (HAMPs). The method was found to be specific, selective, accurate, precise, and robust toward the alkaloids with linearity achieved within specified concentration ranges (r2 &gt; 0.995 for all analytes). Analyte stability ranged between 6 and 12 hours. All the APIs contained quinine &lt;99.0%–101.0%, with dihydroquinine and cinchonidine at levels compliant with the established acceptance criteria. The QBPAFs had quinine content ranging between 50.2% and 151.2%, with 43.5% (n = 10/23) of them complying with the acceptance criteria. The related alkaloids observed in the QBPAFs included quinidine (56.5%, n = 13/23), dihydroquinine (100%, n = 23/23), dihydroquinidine (21.7%, n = 5/23), cinchonine (17.4%, n = 4/23), and cinchonidine (95.7%, n = 22/23). For the HAMPs, 81.0% (n = 17/21) were adulterated with quinine (0.59 ± 0.04 mg/10 mL–86.03 ± 0.02 mg/10 mL). Cryptolepine was identified in 19% (n = 4/21) of the HAMPs with concentration ranging between 43.99 ± 0.43 μg/mL and 747.86 ± 0.34 μg/mL. In conclusion, the application of the ion-pair HPLC method targeting quinoline and indoloquinoline antimalarials has demonstrated the presence of quality and poor-quality HPAFs on the Ghanaian market.