The human malaria-Aotus monkey model: a historical perspective in antimalarial chemotherapy research at the Gorgas Memorial Laboratory-Panama.

The human malaria-Aotus monkey model has served the malaria research community since its inception in 1966 at the Gorgas Memorial Laboratory (GML) in Panama. Spanning over five decades, this model has been instrumental in evaluating the in vivo efficacy and pharmacokinetics of a wide array of candidate antimalarial drugs, whether used singly or in combination. The animal model could be infected with drug-resistant and susceptible Plasmodium falciparum and Plasmodium vivax strains that follow a characteristic and reproducible course of infection, remarkably like human untreated and treated infections. Over the years, the model has enabled the evaluation of several synthetic and semisynthetic endoperoxides, for instance, artelinic acid, artesunate, artemether, arteether, and artemisone. These compounds have been evaluated alone and in combination with long-acting partner drugs, commonly referred to as artemisinin-based combination therapies, which are recommended as first-line treatment against uncomplicated malaria. Further, the model has also supported the evaluation of the primaquine analog tafenoquine against blood stages of P. vivax, contributing to its progression to clinical trials and eventual approval. Besides, the P. falciparum/Aotus model at GML has also played a pivotal role in exploring the biology, immunology, and pathogenesis of malaria and in the characterization of drug-resistant P. falciparum and P. vivax strains. This minireview offers a historical overview of the most significant contributions made by the Panamanian owl monkey (Aotus lemurinus lemurinus) to malaria chemotherapy research.

Analysis of the interaction of antimalarial agents with Plasmodium falciparum glutathione reductase through molecular mechanical calculations.

CONTEXT: Malaria remains a significant global health challenge with emerging resistance to current treatments. Plasmodium falciparum glutathione reductase (PfGR) plays a critical role in the defense mechanisms of malaria parasites against oxidative stress. In this study, we investigate the potential of targeting PfGR with conventional antimalarials and dual drugs combining aminoquinoline derivatives with GR inhibitors, which reveal promising interactions between PfGR and studied drugs. The naphthoquinone Atovaquone demonstrated particularly high affinity and potential dual-mode binding with the enzyme active site and cavity. Furthermore, dual drugs exhibit enhanced binding affinity, suggesting their efficacy in inhibiting PfGR, where the aliphatic ester bond (linker) is essential for effective binding with the enzyme's active site. Overall, this research provides important insights into the interactions between antimalarial agents and PfGR and encourages further exploration of its role in the mechanisms of action of antimalarials, including dual drugs, to enhance antiparasitic efficacy. METHODS: The drugs were tested as PfGR potential inhibitors via molecular docking on AutoDock 4, which was performed based on the preoptimized structures in HF/3-21G-PCM level of theory on ORCA 5. Drug-receptor systems with the most promising binding affinities were then studied with a molecular dynamic's simulation on AMBER 16. The molecular dynamics simulations were performed with a 100 ns NPT ensemble employing GAFF2 forcefield in the temperature of 310 K, integration time step of 2 fs, and non-bond cutoff distance of 6.0 Å.

Association of systemic lupus erythematosus standard of care immunosuppressants with glucocorticoid use and disease outcomes: a multicentre cohort study.

BACKGROUND: This study examines the association of standard-of-care systemic lupus erythematosus (SLE) medications with key outcomes such as low disease activity attainment, flares, damage accrual, and steroid-sparing, for which there is current paucity of data. METHODS: The Asia Pacific Lupus Collaboration (APLC) prospectively collects data across numerous sites regarding demographic and disease characteristics, medication use, and lupus outcomes. Using propensity score methods and panel logistic regression models, we determined the association between lupus medications and outcomes. RESULTS: Among 1707 patients followed over 12,689 visits for a median of 2.19 years, 1332 (78.03%) patients achieved the Lupus Low Disease Activity State (LLDAS), 976 (57.18%) experienced flares, and on most visits patients were taking an anti-malarial (69.86%) or immunosuppressive drug (76.37%). Prednisolone, hydroxychloroquine and azathioprine were utilised with similar frequency across all organ domains; methotrexate for musculoskeletal activity. There were differences in medication utilisation between countries, with hydroxychloroquine less frequently, and calcineurin inhibitors more frequently, used in Japan. More patients taking leflunomide, methotrexate, chloroquine/hydroxychloroquine, azathioprine, and mycophenolate mofetil/mycophenolic acid were taking ≤ 7.5 mg/day of prednisolone (compared to > 7.5 mg/day) suggesting a steroid-sparing effect. Patients taking tacrolimus were more likely (Odds Ratio [95% Confidence Interval] 13.58 [2.23-82.78], p = 0.005) to attain LLDAS. Patients taking azathioprine (OR 0.67 [0.53-0.86], p = 0.001) and methotrexate (OR 0.68 [0.47-0.98], p = 0.038) were less likely to attain LLDAS. Patients taking mycophenolate mofetil were less likely to experience a flare (OR 0.79 [0.64-0.97], p = 0.025). None of the drugs was associated with a reduction in damage accrual. CONCLUSIONS: This study suggests a steroid-sparing benefit for most commonly used standard of care immunosuppressants used in SLE treatment, some of which were associated with an increased likelihood of attaining LLDAS, or reduced incidence of flares. It also highlights the unmet need for effective treatments in lupus.

The effect of antimalarials on the safety and persistence of treatment with biologic agents or Janus kinase inhibitors in rheumatoid arthritis.

OBJECTIVES: To test the association of use of antimalarials with the overall safety of treatment in RA patients receiving one or multiple courses of biologic (b)DMARDs or a Janus kinase inhibitor (JAKi). METHODS: BiobadaBrasil is a multicentric registry-based cohort study of Brazilian patients with rheumatic diseases starting their first bDMARD or JAKi. The present analysis includes RA patients recruited from January 2009 to October 2019, followed up over one or multiple (up to six) courses of treatment (latest date, 19 November 2019). The primary outcome was the incidence of serious adverse events (SAEs). Total and system-specific adverse events (AEs) and treatment interruption served as secondary outcomes. Negative binomial regression with generalized estimating equations (to estimate multivariate incidence rate ratios, mIRR) and frailty Cox proportional hazards models were used for statistical analyses. RESULTS: The number of patients enrolled was 1316 (2335 treatment courses, 6711 patient-years [PY]; 1254.5 PY on antimalarials). The overall incidence of SAEs was 9.2/100 PY. Antimalarials were associated with reduced risk of SAEs (mIRR: 0.49; 95% CI: 0.36, 0.68; P < 0.001), total AEs (0.68; 95% CI: 0.56, 0.81; P < 0.001), serious infections (0.53; 95% CI: 0.34, 0.84; P = 0.007) and total hepatic AEs (0.21; 95% CI: 0.05, 0.85; P = 0.028). Antimalarials were also related to better survival of treatment course (P = 0.003). There was no significant increase in the risk of cardiovascular AEs. CONCLUSION: Among RA patients on treatment with bDMARDs or JAKi, concomitant use of antimalarials was associated with reduced the incidence of serious and total AEs and with longer treatment course survival.

Brazilian plants with antimalarial activity: A review of the period from 2011 to 2022.

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria continues to be a serious global public health problem in subtropical and tropical countries of the world. The main drugs used in the treatment of human malaria, quinine and artemisinin, are isolates of medicinal plants, making the use of plants a widespread practice in countries where malaria is endemic. Over the years, due to the increased resistance of the parasite to chloroquine and artemisinin in certain regions, new strategies for combating malaria have been employed, including research with medicinal plants. AIM: This review focuses on the scientific production regarding medicinal plants from Brazil whose antimalarial activity was evaluated during the period from 2011 to 2022. 2. METHODOLOGY: For this review, four electronic databases were selected for research: Pubmed, ScienceDirect, Scielo and Periódicos CAPES. Searches were made for full texts published in the form of scientific articles written in Portuguese or English and in a digital format. In addition, prospects for new treatments as well as future research that encourages the search for natural products and antimalarial derivatives are also presented. RESULTS: A total of 61 publications were encountered, which cited 36 botanical families and 92 species using different Plasmodium strains in in vitro and in vivo assays. The botanical families with the most expressive number of species found were Rubiaceae, Apocynaceae, Fabaceae and Asteraceae (14, 14, 9 and 6 species, respectively), and the most frequently cited species were of the genera Psychotria L. (8) and Aspidosperma Mart. (12), which belong to the families Rubiaceae and Apocynaceae. Altogether, 75 compounds were identified or isolated from 28 different species, 31 of which are alkaloids. In addition, the extracts of the analyzed species, including the isolated compounds, showed a significant reduction of parasitemia in P. falciparum and P. berghei, especially in the clones W2 CQ-R (in vitro) and ANKA (in vivo), respectively. The Brazilian regions with the highest number of species analyzed were those of the north, especially the states of Pará and Amazonas, and the southeast, especially the state of Minas Gerais. CONCLUSION: Although many plant species with antimalarial potential have been identified in Brazil, studies of new antimalarial molecules are slow and have not evolved to the production of a phytotherapeutic medicine. Given this, investigations of plants of traditional use and biotechnological approaches are necessary for the discovery of natural antimalarial products that contribute to the treatment of the disease in the country and in other endemic regions.

Identification of potential inhibitors of casein kinase 2 alpha of Plasmodium falciparum with potent in vitro activity.

Drug resistance to commercially available antimalarials is a major obstacle in malaria control and elimination, creating the need to find new antiparasitic compounds with novel mechanisms of action. The success of kinase inhibitors for oncological treatments has paved the way for the exploitation of protein kinases as drug targets in various diseases, including malaria. Casein kinases are ubiquitous serine/threonine kinases involved in a wide range of cellular processes such as mitotic checkpoint signaling, DNA damage response, and circadian rhythm. In Plasmodium, it is suggested that these protein kinases are essential for both asexual and sexual blood-stage parasites, reinforcing their potential as targets for multi-stage antimalarials. To identify new putative PfCK2α inhibitors, we utilized an in silico chemogenomic strategy involving virtual screening with docking simulations and quantitative structure-activity relationship predictions. Our investigation resulted in the discovery of a new quinazoline molecule (542), which exhibited potent activity against asexual blood stages and a high selectivity index (>100). Subsequently, we conducted chemical-genetic interaction analysis on yeasts with mutations in casein kinases. Our chemical-genetic interaction results are consistent with the hypothesis that 542 inhibits yeast Cka1, which has a hinge region with high similarity to PfCK2α. This finding is in agreement with our in silico results suggesting that 542 inhibits PfCK2α via hinge region interaction.

Toxins from Animal Venoms as a Potential Source of Antimalarials: A Comprehensive Review.

Malaria is an infectious disease caused by Plasmodium spp. and it is mainly transmitted to humans by female mosquitoes of the genus Anopheles. Malaria is an important global public health problem due to its high rates of morbidity and mortality. At present, drug therapies and vector control with insecticides are respectively the most commonly used methods for the treatment and control of malaria. However, several studies have shown the resistance of Plasmodium to drugs that are recommended for the treatment of malaria. In view of this, it is necessary to carry out studies to discover new antimalarial molecules as lead compounds for the development of new medicines. In this sense, in the last few decades, animal venoms have attracted attention as a potential source for new antimalarial molecules. Therefore, the aim of this review was to summarize animal venom toxins with antimalarial activity found in the literature. From this research, 50 isolated substances, 4 venom fractions and 7 venom extracts from animals such as anurans, spiders, scorpions, snakes, and bees were identified. These toxins act as inhibitors at different key points in the biological cycle of Plasmodium and may be important in the context of the resistance of Plasmodium to currently available antimalarial drugs.

Biological activity of 1,2,3-triazole-2-amino-1,4-naphthoquinone derivatives and their evaluation as therapeutic strategy for malaria control.

Malaria can be caused by several Plasmodium species and the development of an effective vaccine is challenging. Currently, the most effective tool to control the disease is the administration of specific chemotherapy; however, resistance to the frontline antimalarials is one of the major problems in malaria control and thus the development of new drugs becomes urgent. The study presented here sought to evaluate the antimalarial activities of compounds derived from 2-amino-1,4-naphthoquinones containing 1,2,3-triazole using in vivo and in vitro models. 1H-1,2,3-Triazole 2-amino-1,4-naphthoquinone derivatives were synthesized and evaluated for antimalarial activity in vitro, using P. falciparum W2 chloroquine (CQ) resistant strain and in vivo using the murine-P. berghei ANKA strain. Acute toxicity was determined as established by the OECD (2001). Cytotoxicity was evaluated against HepG2 and Vero mammalian cell lines. Transmission electron microscopy of the Plasmodium falciparum trophozoite (early and late stages) was used to evaluate the action of compounds derived at ultra-structural level. The compounds displayed low cytotoxicity CC50 > 100 µM, neither did they cause hemolysis at the tested doses and nor the signs of toxicity in the in vivo acute toxicity test. Among the five compounds tested, one showed IC50 values in submicromolar range of 0.8 µM. Compounds 7, 8 and 11 showed IC50 values < 5 µM, and selectivity index (SI) ranging from 6.8 to 343 for HepG2, and from 13.7 to 494.8 for Vero cells. Compounds 8 and 11 were partially active against P. berghei induced parasitemia in vivo. Analysis of the ultrastructural changes associated with the treatment of these two compounds, showed trophozoites with completely degraded cytoplasm, loss of membrane integrity, organelles in the decomposition stage and possible food vacuole deterioration. Our results indicated that compounds 8 and 11 may be considered hit molecules for antimalarial drug discovery platform and deserve further optimization studies.

Antimalarials and amphotericin B interact synergistically and are new options to treat cryptococcosis.

Cryptococcus gattii and Cryptococcus neoformans are the main etiological agents of cryptococcosis, an invasive mycosis treated with amphotericin B, 5-fluorocytosine, and fluconazole. This limited arsenal is toxic and is associated with antifungal resistance. Cryptococcosis and malaria pathogens are eukaryotic organisms that have a high incidence in Sub-Saharan Africa. The antimalarials (ATMs) halofantrine (HAL) and amodiaquine (AQ) block Plasmodium heme polymerase, and artesunate (ART) induces oxidative stress. Considering that Cryptococcus spp. is susceptible to reactive oxygen species and that iron is essential for metabolism, the repurposing of ATMs for treating cryptococcosis was tested. ATMs reduced fungal growth, induced oxidative and nitrosative stresses, and altered ergosterol content, melanin production, and polysaccharide capsule size in C. neoformans and C. gattii, revealing a dynamic effect on fungal physiology. A comprehensive chemical-genetic analysis using two mutant libraries demonstrated that the deletion of genes involved in synthesizing components of the plasma membrane and cell wall, and oxidative stress responses are essential for fungal susceptibility to ATMs. Interestingly, the amphotericin B (AMB) fungicidal concentrations were ∼10 times lower when combined with ATMs, demonstrating a synergistic interaction. Further, the combinations showed reduced toxicity to murine macrophages. Finally, HAL+AMB and AQ+AMB efficiently reduced lethality and fungal burden in the lungs and brain in murine cryptococcosis. These findings provide perspectives for further studies with ATMs against cryptococcosis and other fungal infections.

Synthesis, Structure−Activity Relationships, and Parasitological Profiling of Brussonol Derivatives as New Plasmodium falciparum Inhibitors

Malaria is a parasitic disease caused by protozoan parasites from the genus Plasmodium. Plasmodium falciparum is the most prevalent species worldwide and the causative agent of severe malaria. The spread of resistance to the currently available antimalarial therapy is a major concern. Therefore, it is imperative to discover and develop new antimalarial drugs, which not only treat the disease but also control the emerging resistance. Brussonol is an icetexane derivative and a member of a family of diterpenoids that have been isolated from several terrestrial plants. Here, the synthesis and antiplasmodial profiling of a series of brussonol derivatives are reported. The compounds showed inhibitory activities in the low micromolar range against a panel of sensitive and resistant P. falciparum strains (IC50s = 5-16 µM). Moreover, brussonol showed fast-acting in vitro inhibition and an additive inhibitory behavior when combined with the antimalarial artesunate (FICindex~1). The mode of action investigation indicated that brussonol increased the cytosolic calcium levels within the parasite. Hence, the discovery of brussonol as a new scaffold endowed with antiplasmodial activity will enable us to design derivatives with improved properties to deliver new lead candidates for malaria.

Knowledge of Malaria and Its Uncomplicated Treatment with Argemone mexicana L. in Selected Districts of Jimma Zone, Oromia Regional State, Ethiopia: A Community-Based Cross Sectional Survey.

Background: With the problems of increasing levels of drug resistance and difficulties to afford and access effective antimalarial drugs in poor and remote areas, herbal medicines could be an important and sustainable source of treatment. Argemone mexicana L. (AM) is a medicinal plant known long ago in several countries for treatment of numerous diseases including malaria. The aim of this study was to conduct a survey on the use of AM in the prevention and treatment of uncomplicated malaria in selected districts of Jimma Zone, Oromia Regional state, Ethiopia. Methods: A community-based cross-sectional study was conducted in two selected districts in Jimma Zone, southwest Ethiopia. In total, 552 participants from 17 kebeles (villages/communities) and 18 traditional healers of the districts were interviewed. Data collection was conducted from April 27 to May 18, 2020 using pre-tested structured questionnaires. The data were analyzed using Epi Info 7.0 and the descriptive statistics were used to summarize the results. Results: The study indicated that AM is available, known by 39.8% of the respondents and used for prevention and treatment of malaria by 5.7% of the population. All traditional healers interviewed knew the plant, and 44.4% use it for treatment of malaria. In addition, AM is especially used to treat malaria, amoebiasis, diarrhea, cough, and tuberculosis. Conclusion: The availability and use of AM to treat malaria was verified in both community and traditional healers. AM, which was found effective as antimalarial plant in high Plasmodium falciparum endemicity in Mali, is also well known and accepted in these areas of Ethiopia for the treatment of malaria. Further research is needed to assess wether AM is also effective against malaria in Ethiopia where P. vivax and P. falciparum coexist.

Reaching the malaria elimination goal in Brazil: a spatial analysis and time-series study.

BACKGROUND: Since 2015, the Global Technical Strategy (GTS) for Malaria 2016-2030 has been adopted by the World Health Organization (WHO) as a comprehensive framework to accelerate progress for malaria elimination in endemic countries. This strategy sets the target of reducing global malaria incidence and mortality rates by 90% in 2030. Here it is sought to evaluate Brazil's achievements towards reaching the WHO GTS milestone in 2030. Considering the total number of new malaria cases in 2015, the main research question is: will Brazil reach the malaria elimination goal in 2030? METHODS: Analytical strategies were undertaken using the SIVEP-malaria official databases of the Brazilian Malaria Control Programme for the Brazilian Amazon region from 2009 to 2020. Spatial and time-series analyses were applied for identifying municipalities that support the highest numbers of malaria cases over the years. Forecast analysis was used for predicting the estimated number of new cases in Brazil in 2025-2050. RESULTS: Brazil has significantly reduced the number of new malaria cases in 2020 in comparison with 2015 in the states of Acre (- 56%), Amapá (- 75%), and Amazonas (- 21%); however, they increased in the states of Pará (156%), Rondônia (74%), and Roraima (362%). Forecast of the predicted number of new malaria cases in 2030 is 74,764 (95% CI: 41,116-141,160) in the Brazilian Amazon. CONCLUSIONS: It is likely that Brazil will reduce the number of new malaria cases in the Brazilian Amazon in 2030 in relation to that in 2015. Herein forecast shows a reduction by 46% (74,754 in 2030 forecast/137,982 in 2015), but this reduction is yet far from the proposed reduction under the WHO GTS 2030 milestone (90%). Stable and unbeatable transmission in the Juruá River Valley, Manaus, and Lábrea still support endemic malaria in the Brazilian Amazon. Today's cross-border malaria is impacting the state of Roraima unprecedently. If this situation is maintained, the malaria elimination goal (zero cases) may not be reached before 2050. An enhanced political commitment is vital to ensure optimal public health intervention designs in the post-2030 milestones for malaria elimination.

New Trends in Biological Activities and Clinical Studies of Quinolinic Analogues: A Review.

The quinolinic ring, present in several molecules, possesses a great diversity of biological activities. Therefore, this ring is in the structural composition of several candidates of drugs in preclinical and clinical studies; thus, it is necessary to compile these results to facilitate the design of new drugs. For this reason, some of the activities of compounds are selected to examine in this review, such as antimalarial, antimicrobial, anticancer, anti-inflammatory, antidiabetic, anti-rheumatic, and antiviral activities. All publications of scientific articles chosen are dated between 2000 and 2020. In addition to presenting the structures of some natural and synthetic compounds with their activities, we have listed the clinical studies of phases III and IV on antimalarial drugs containing the quinoline nucleus and phase III clinical studies on hydroxychloroquine and chloroquine to assess their possible role in COVID-19. Finally, we have reviewed some of the mechanisms of action, as well as the side effects of some of the quinolinic derivatives.

Hydroxychloroquine use and blood pressure below 130/80 are associated with remission in lupus nephritis: A cohort study / El uso de hidroxicloroquina y las cifras de presión arterial por debajo de 130/80 se asocian con remisión en nefritis lúpica: un estudio de cohorte

ABSTRACT Introduction: The treatment of lupus nephritis, in addition to immunosuppression, includes the use of adjuvant therapies (antimalarials, statins, blockade of the renin-angiotensin system, and the achievement of blood pressure levels below 130/80). The evidence for the use of these strategies comes from non-autoimmune primary glomerulopathies and there is no information on their impact on the remission of this condition. Objective: To determine, in patients with lupus nephritis, the use of adjuvant therapies and their association with remission at 12 months. Materials and methods: A retrospective cohort study was conducted, between 2005 and 2012. Patients who achieved complete remission of nephritis were compared with those who did not. Complete remission was defined by the American College of Rheumatology AdHoc Subcommittee. Outcomes: Percentage of use of adjuvant therapies. Bivariate and multivariate analysis were performed to define association with remission. Results: 167 subjects were included (all eligible subjects); 85.6% used antimalarials, 65.5% angiotensin converting enzyme inhibitors, 33.5% angiotensin receptor blockers, 30.7% dual blockade, 29.3% statins, and 85% achieved the goal blood pressure. In the multivariate analysis, the use of hydroxychloroquine (OR = .149; 95% CI: .034-.647; p = .003) and the achievement of goal blood pressure (OR = .248; 95% CI: .1-.615; p = .003) were associated with remission. Conclusions: In a cohort of patients with lupus nephritis, the use of hydroxychloroquine and achieving blood pressure values lower than 130/80 were associated with remission at 12 months.

RESUMEN Introducción: El tratamiento de la nefritis lúpica, además de la inmunosupresión, comprende el uso de terapias adyuvantes (antimaláricos, estatinas, bloqueo del sistema renina angiotensina y el logro de cifras de presión arterial menores de 130/80). La evidencia del uso de estas estrategias proviene de glomerulopatías primarias no autoinmunes y no hay información de su impacto en la remisión de esta condición. Objetivos: Determinar, en pacientes con nefritis lúpica, la utilización de terapias adyuvantes y su asociación con remisión a 12 meses. Materiales y métodos: Se realizó un estudio de cohortes retrospectivo, entre 2005 y 2012. Se compararon los pacientes que lograron remisión completa de la nefritis con aquellos que no lo consiguieron. La remisión completa se definió según el Subcomité AdHoc del American College of Rheumatology. Desenlaces: Porcentaje de utilización de terapias adyuvantes. Análisis: bivariado y multivariado para definir asociación con remisión. Resultados: Se incluyeron 167 pacientes (todos los sujetos elegibles). Un 85,6% utilizó antimaláricos, un 65,5% inhibidores de enzima convertidora de angiotensina, 33,5% bloqueadores del receptor de angiotensina, 30,7% bloqueo dual, 29,3% estatinas y en un 85% se logró la meta de presión arterial. En el análisis multivariado, el uso de hidroxicloroquina (OR = 0,149; IC 95%: 0,034-0,647; p = 0,003) y el logro de la meta de presión arterial (OR = 0,248; IC 95%: 0,1-0,615; p = 0,003) se asociaron a remisión. Conclusiones: En una cohorte de pacientes con nefritis lúpica, el uso de hidroxicloroquina y lograr cifras de presión arterial menores a 130/80 se asociaron a remisión a 12 meses.

Studies on Activities and Chemical Characterization of Medicinal Plants in Search for New Antimalarials: A Ten Year Review on Ethnopharmacology.

Malaria is an endemic disease that affected 229 million people and caused 409 thousand deaths, in 2019. Disease control is based on early diagnosis and specific treatment with antimalarial drugs since no effective vaccines are commercially available to prevent the disease. Drug chemotherapy has a strong historical link to the use of traditional plant infusions and other natural products in various cultures. The research based on such knowledge has yielded two drugs in medicine: the alkaloid quinine from Cinchona species, native in the Amazon highland rain forest in South America, and artemisinin from Artemisia annua, a species from the millenary Chinese medicine. The artemisinin-based combination therapies (ACTs), proven to be highly effective against malaria parasites, and considered as "the last bullet to fight drug-resistant malaria parasites," have limited use now due to the emergence of multidrug resistance. In addition, the limited number of therapeutic options makes urgent the development of new antimalarial drugs. This review focuses on the antimalarial activities of 90 plant species obtained from a search using Pubmed database with keywords "antimalarials," "plants" and "natural products." We selected only papers published in the last 10 years (2011-2020), with a further analysis of those which were tested experimentally in malaria infected mice. Most plant species studied were from the African continent, followed by Asia and South America; their antimalarial activities were evaluated against asexual blood parasites, and only one species was evaluated for transmission blocking activity. Only a few compounds isolated from these plants were active and had their mechanisms of action delineated, thereby limiting the contribution of these medicinal plants as sources of novel antimalarial pharmacophores, which are highly necessary for the development of effective drugs. Nevertheless, the search for bioactive compounds remains as a promising strategy for the development of new antimalarials and the validation of traditional treatments against malaria. One species native in South America, Ampelozyzyphus amazonicus, and is largely used against human malaria in Brazil has a prophylactic effect, interfering with the viability of sporozoites in in vitro and in vivo experiments.

The impact of antimalarial agents on traditional and non-traditional subclinical atherosclerosis biomarkers in systemic lupus erythematosus: A systematic review and meta-analysis.

OBJECTIVE: Cardiovascular (CV) morbidity is a well-established problem in systemic lupus erythematosus (SLE). Antimalarial (AM) therapy has been seen as a potential atheroprotective agent. The aim was to assess the impact of AM therapy on traditional and novel atherosclerosis (AT) biomarkers in patients with SLE. METHODS: A search of MEDLINE, EMbase, and Cochrane library for studies evaluating the impact of AM on AT biomarkers in SLE was conducted. Data extraction included serum, functional and structural traditional and novel biomarkers. A narrative synthesis of the findings and a meta-analysis with random effects was conducted estimating mean differences (MD), OR, HR and 95% CIs. RESULTS: The search strategy produced 148 articles, of which 64 were extracted for analysis. The MD in VLDL-cholesterol (-10.29, 95% CI -15.35, 5.24), triglycerides (-15.68, 95% CI -27.51, -3.86), and diastolic BP (-3.42, 95% CI -5.62, -1.23) differed significantly in patients on AM therapy compared with those without AM therapy. Patients on AM had a lower prevalence and incidence of diabetes mellitus than patients not on AM (HR: 0.39, 95% CI 0.17, 0.88). HCQ use was associated with lower blood pressure (BP) variability. Structural markers like carotid intima-media thickness (IMT), carotid plaque (CP) and coronary artery calcification (CAC) were not influenced by AM. For functional markers like endothelial and arterial stiffness the benefit was unclear. The GRADE approach showed a very low-to-low quality of evidence (QoE) per outcome. CONCLUSIONS: There is some evidence on the associations between AM therapy and some AT markers. However, the data on which this conclusion was based was of low to very low evidence.

Recomendaciones para reumatólogos sobre el manejo farmacológico durante la emergencia sanitaria por COVID-19: opinión de un grupo de expertos / Recommendations for rheumatologists on pharmacological management during the COVID-19 health emergency: Expert group opinion

RESUMEN La enfermedad por Coronavirus 2019 (COVID-19) es una pandemia inesperada que ha pro vocado un estado de emergencia y que ha generado cambios drásticos en los protocolos de atención clínica. Para su tratamiento se ha descrito el papel de algunos medicamen tos usados habitualmente en artritis reumatoide, lupus eritematoso sistémico y otras enfermedades autoinmunitarias sistémicas. Debido a ello, existe un inminente riesgo de desabastecimiento, por lo cual el objetivo de esta revisión narrativa y opinión de expertos es formular recomendaciones generales clínicas y administrativas sobre el manejo de pacien tes ambulatorios con enfermedad autoinmunitaria o inflamatoria sistémica en el contexto de la pandemia por COVID-19.

ABSTRACT Coronavirus 2019 (COVID-19) is an unexpected pandemic that has caused a state of emergency, as well as generating drastic changes in clinical care protocols. Some drugs commonly used in rheumatoid arthritis, systemic lupus erythematosus, and other systemic autoimmune diseases have been described for its treatment. Therefore, there is an imminent risk of shortages. The aim of this narrative review and expert opinion is to present general recommendations on the clinical and administrative management of outpatients with autoimmune or systemic inflammatory disease, in the context of the COVID-19 pandemic.

The Knockout for G Protein-Coupled Receptor-Like PfSR25 Increases the Susceptibility of Malaria Parasites to the Antimalarials Lumefantrine and Piperaquine but Not to Medicine for Malaria Venture Compounds.

Previously we have reported that the G protein-coupled receptor (GPCR)-like PfSR25 in Plasmodium falciparum is a potassium (K+) sensor linked to intracellular calcium signaling and that knockout parasites (PfSR25-) are more susceptible to oxidative stress and antimalarial compounds. Here, we explore the potential role of PfSR25 in susceptibility to the antimalarial compounds atovaquone, chloroquine, dihydroartemisinin, lumefantrine, mefloquine, piperaquine, primaquine, and pyrimethamine and the Medicine for Malaria Venture (MMV) compounds previously described to act on egress/invasion (MMV006429, MMV396715, MMV019127, MMV665874, MMV665878, MMV665785, and MMV66583) through comparative assays with PfSR25- and 3D7 parasite strains, using flow cytometry assays. The IC50 and IC90 results show that lumefantrine and piperaquine have greater activity on the PfSR25- parasite strain when compared to 3D7. For MMV compounds, we found no differences between the strains except for the compound MMV665831, which we used to investigate the store-operated calcium entry (SOCE) mechanism. The results suggest that PfSR25 may be involved in the mechanism of action of the antimalarials lumefantrine and piperaquine. Our data clearly show that MMV665831 does not affect calcium entry in parasites after we depleted their internal calcium pools with thapsigargin. The results demonstrated here shed light on new possibilities on the antimalarial mechanism, bringing evidence of the involvement of the GPCR-like PfSR25.

Hearing of neonates without risk indicators for hearing loss and use of antimalarial drugs during pregnancy: a historical cohort study in the Northern Region of Brazil / Audição de neonatos sem indicadores de risco para perda auditiva e utilização de antimaláricos na gestação: um estudo de coorte histórica na Região Norte

Abstract Introduction: Studies have demonstrated the ototoxic effects of antimalarial drugs in individuals who receive these drugs, but little is known regarding the toxicity of these drugs in the newborn auditory system when administered to the mother receive the drug during pregnancy. Objective: To verify the incidence of hearing loss in neonates who have no other associated risk indicators, born to mothers treated for malaria during pregnancy. Methods: A retrospective, quantitative cohort study was developed at Hospital de Base Dr. Ary Pinheiro and Clínica Limiar, both located in the municipality of Porto Velho (Rondônia). The sample consisted of 527 newborns divided into two groups: exposed to antimalarials drugs during pregnancy group (n = 32) and non-exposed group (n = 495). Data collection took place from September 2014 to December 2015, through an interview with the mothers and/or guardians of the newborn, through the newborns' and the mothers' records, and the neonatal hearing screening database of the above-mentioned institutions. Results: All the neonates in the exposed group, assessed through the recording of transient otoacoustic emissions associated with the automated brainstem auditory evoked potential test, underwent neonatal hearing screening in the first examination. Among the newborns in the non-exposed group, 30 showed failure and were retested. Of these, one continued to fail and was referred for diagnosis, in whom the results showed to be within the normal range. Among the neonates of the exposed group, infection with Plasmodium vivax was the most frequent, and was similarly distributed among the gestational trimesters, and chloroquine was the most commonly used antimalarial drug treatment more often given during the third trimester; these findings did not show any influence on the audiological findings of the studied neonates. Conclusion: The present study did not identify any cases of hearing loss in neonates born to mothers who used antimalarial drugs during gestation.

Resumo Introdução: Estudos comprovam os efeitos ototóxicos dos antimaláricos em pessoas que fazem uso destes medicamentos, porém pouco se sabe sobre a toxicidade destes fármacos no sistema auditivo de neonatos quando ingeridos pelas mães no período gestacional. Objetivo: Verificar a incidência de perda auditiva em neonatos de mães tratadas para malária durante a gestação sem outros indicadores de risco associados. Método: Estudo quantitativo, de coorte retrospectivo, desenvolvido no Hospital de Base Dr. Ary Pinheiro e na Clínica Limiar, ambos em Porto Velho (Rondônia). Compuseram a amostra 527 recém-nascidos divididos em dois grupos: grupo exposto (n = 32) e grupo não exposto (n = 495). A coleta de dados ocorreu de setembro de 2014 a dezembro de 2015, através de entrevista com as genitoras e/ou responsáveis pelo recém-nascido, investigação nos prontuários dos neonatos e das genitoras e no banco de dados da triagem auditiva neonatal das instituições supracitadas. Resultados: Todos os neonatos do grupo exposto, avaliados através do registro das emissões otoacústicas transientes associado a realização do potencial evocado auditivo de tronco encefálico automático passaram na triagem auditiva neonatal no primeiro exame. Já, entre os recém-nascidos do grupo não exposto, 30 apresentaram falha e foram retestados. Destes, um continuou falhando e foi encaminhado para diagnóstico, no qual foram evidenciados resultados dentro da normalidade. Nos neonatos do grupo exposto, a infecção pelo Plasmodium vivax foi a mais frequente, mostrando distribuição semelhante entre os trimestres gestacionais, sendo a cloroquina o antimalárico mais utilizado e o tratamento medicamentoso realizado mais frequentemente no terceiro trimestre, porém tais achados não mostraram influência sobre os achados audiológicos dos neonatos estudados. Conclusão: O presente estudo não identificou casos de perda auditiva nos neonatos de mães que utilizaram antimaláricos na gestação.

Hearing of neonates without risk indicators for hearing loss and use of antimalarial drugs during pregnancy: a historical cohort study in the Northern Region of Brazil.

INTRODUCTION: Studies have demonstrated the ototoxic effects of antimalarial drugs in individuals who receive these drugs, but little is known regarding the toxicity of these drugs in the newborn auditory system when administered to the mother receive the drug during pregnancy. OBJECTIVE: To verify the incidence of hearing loss in neonates who have no other associated risk indicators, born to mothers treated for malaria during pregnancy. METHODS: A retrospective, quantitative cohort study was developed at Hospital de Base Dr. Ary Pinheiro and Clínica Limiar, both located in the municipality of Porto Velho (Rondônia). The sample consisted of 527 newborns divided into two groups: exposed to antimalarials drugs during pregnancy group (n = 32) and non-exposed group (n = 495). Data collection took place from September 2014 to December 2015, through an interview with the mothers and/or guardians of the newborn, through the newborns' and the mothers' records, and the neonatal hearing screening database of the above-mentioned institutions. RESULTS: All the neonates in the exposed group, assessed through the recording of transient otoacoustic emissions associated with the automated brainstem auditory evoked potential test, underwent neonatal hearing screening in the first examination. Among the newborns in the non-exposed group, 30 showed failure and were retested. Of these, one continued to fail and was referred for diagnosis, in whom the results showed to be within the normal range. Among the neonates of the exposed group, infection with Plasmodium vivax was the most frequent, and was similarly distributed among the gestational trimesters, and chloroquine was the most commonly used antimalarial drug treatment more often given during the third trimester; these findings did not show any influence on the audiological findings of the studied neonates. CONCLUSION: The present study did not identify any cases of hearing loss in neonates born to mothers who used antimalarial drugs during gestation.