Safety and pharmacokinetic properties of a new formulation of parenteral artesunate in healthy Thai volunteers.

BACKGROUND: Parenteral artesunate is the first-line therapy for severe malaria. Artesunate, in its current formulation, must be prepared immediately before administration by first dissolving in sodium bicarbonate solution and then diluting in saline. A novel solvent for rapid and stable single step reconstitution of artesunate was recently developed showing improved solubility and stability. This study aimed to compare the safety and pharmacokinetic properties of the currently available and newly developed parenteral formulation of artesunate in healthy Thai volunteers. METHODS: This was an open-label, randomized, 4 periods, 4-treatments, 24-sequence, single-dose, cross-over study in 72 male and female healthy Thai volunteers. Frequent pharmacokinetic samples were collected in all volunteers at each dose occasion. Observed concentration-time profiles were analysed with a non-compartmental approach followed by a bioequivalence evaluation. RESULTS: Both intramuscular and intravenous administrations of the new parenteral formulation of artesunate were safe and well-tolerated, with no additional safety signals compared to the currently used formulation. The pharmacokinetic properties of artesunate and its active metabolite, dihydroartemisinin, were well-characterized, and showed rapid conversion of artesunate into dihydroartemisinin. Intramuscular administration of the newly formulated artesunate resulted in almost complete bioavailability of dihydroartemisinin. The pharmacokinetic properties were similar between the old and new formulation. CONCLUSIONS: The new and more easily prepared formulation of artesunate was safe and well-tolerated, with similar pharmacokinetic properties compared to the currently used formulation. Dihydroartemisinin, the active metabolite responsible for the majority of the anti-malarial effect, showed equivalent exposure after both intravenous and intramuscular administration of artesunate, suggesting that both routes of administration should generate comparable therapeutic effects. TRIAL REGISTRATION: The study was registered to clinicaltrials.gov (#TCTR20170907002).

Inhibition of HOXC11 by artesunate induces ferroptosis and suppresses ovarian cancer progression through transcriptional regulation of the PROM2/PI3K/AKT pathway.

BACKGROUND: Ferroptosis, a non-apoptotic form of regulated cell death, plays a critical role in the suppression of various tumor types, including ovarian cancer. Artesunate (ART), a derivative of artemisinin, exhibits extensive antitumor effects and is associated with ferroptosis. This study aimed to investigate the mechanisms through which ART induces ferroptosis to inhibit ovarian cancer. METHODS: RNA sequencing was conducted to identify differentially expressed genes associated with ART-induced ferroptosis. Dual-luciferase reporter assays and electrophoretic mobility shift assays were performed to confirm the interaction between Homeobox C11 (HOXC11) and the Prominin 2 (PROM2) promoter. Cell Counting Kit-8 (CCK-8) assays, flow cytometry, and wound healing assays were used to analyze the antitumor effects of ART. Western blot, biochemical assays and transmission electron microscope were utilized to further characterize ART-induced ferroptosis. In vivo, the effects of ART on ferroptosis were examined using a xenograft mouse model. RESULTS: RNA sequencing analysis revealed that the HOXC11, PROM2 and Phosphatidylinositol 3-Kinase/ Protein Kinase B (PI3K/AKT) pathways were downregulated by ART. HOXC11 was found to regulate PROM2 expression by binding to its promoter directly. HOXC11 overexpression reversed ART-induced effects on ovarian cancer cell proliferation, migration, apoptosis and ferroptosis by activating the PROM2/PI3K/AKT signaling axis. Conversely, silencing PROM2 in HOXC11-overexpressing cells restored ART-induced ferroptosis and its associated antitumor effects by inhibiting the PI3K/AKT pathway. Consistently, in vivo studies using a xenograft mouse model confirmed that ART-induced tumor inhibition was mediated by ferroptosis through the suppression of the HOXC11/PROM2/PI3K/AKT pathway. CONCLUSION: This study identifies the HOXC11/PROM2/PI3K/AKT axis as a novel regulatory mechanism underlying ART-induced ferroptosis in ovarian cancer. Targeting the HOXC11/PROM2 axis may represent a promising therapeutic strategy for enhancing ferroptosis, offering new insights for the treatment of ovarian cancer.

NK cells contribute to the resolution of experimental malaria-associated acute respiratory distress syndrome after antimalarial treatment.

In both humans and mice, natural killer (NK) cells are important lymphocytes of the innate immune system. They are often considered pro-inflammatory effector cells but may also have a regulatory or pro-resolving function by switching their cytokine profile towards the production of anti-inflammatory cytokines, including interleukin-10 (IL-10) and transforming growth factor-ß, and by killing pro-inflammatory immune cells. Here, the role of NK cells in the resolution of malaria lung pathology was studied. Malaria complications, such as malaria-associated acute respiratory distress syndrome (MA-ARDS), are often lethal despite the rapid and efficient killing of Plasmodium parasites with antimalarial drugs. Hence, studying the resolution and healing mechanisms involved in the recovery from these complications could be useful to develop adjunctive treatments. Treatment of Plasmodium berghei NK65-infected C57BL/6 mice with a combination of artesunate and chloroquine starting at the appearance of symptoms was used as a model to study the resolution of MA-ARDS. The role of NK cells was studied using anti-NK1.1 depletion antibodies and NK cell-deficient mice. Using both methods, NK cells were found to be dispensable in the development of MA-ARDS, as shown previously. In contrast, NK cells were crucial in the initiation of resolution upon antimalarial treatment, as survival was significantly decreased in the absence of NK cells. Considerably increased IL-10 expression by NK cells suggested an anti-inflammatory and pro-resolving phenotype. Despite the increase in Il10 expression in the NK cells, inhibition of the IL-10/IL-10R axis using anti-IL10R antibodies had no effect on the resolution for MA-ARDS, suggesting that the pro-resolving effect of NK cells cannot solely be attributed to their IL-10 production. In conclusion, NK cells contribute to the resolution of experimental MA-ARDS.

Quality assessment of common anti-malarial medicines marketed in Gambella, National Regional State, South Western-Ethiopia.

BACKGROUND: Over the past years, there has been a growing concern that a considerable amount of anti-malarial supply in the underdeveloped world particularly in the private sector, is of poor quality. The World Health Organization (WHO) has received about 1500 reports that mentions instances of substandard and falsified products since 2013. The majority of the reports concerned antibiotics and anti-malarials. The majority of reports (42%) originate from the WHO African region. OBJECTIVE: This study intends to assess the quality of the most widely used anti-malarial medications [artemether-lumefantrine tablets, chloroquine phosphate tablets, primaquine phosphate tablets, artesunate, and artemether injections] in Gambella, South-West, Ethiopia. METHODS: A total of 52 samples were collected on June 2022 from Gambella National Regional State, Ethiopia. Half of the districts (six) located in the four zones of the region were chosen using simple random sampling technique. All drug retail outlets available in the selected districts (locally known as woredas) were included. The samples were subjected to visual inspection with a tool adopted from the joint WHO/FIP/ USP checklist. The pharmacopeial tests for identification, uniformity of dosage forms, assay, thickness, diameter, hardness, friability, disintegration test, dissolution, and sterility tests were carried out according to the USP 44-NF 39 and International Pharmacopoeia 11th edition, 2022 monographs. RESULTS AND DISCUSSION: Only 25% of the samples were registered on the Ethiopian Food and Drug Authority (EFDA's) electronic regulatory/ registration system (ERIS). Besides, 88.8% of artemether injection products were presented in clear glass ampoules. This might expose the products to photochemical degradation that leads to in loss of anti-plasmodial activity. In addition, 50% of the artemether products assessed were not bioequivalent with the comparator product in the in vitro dissolution comparison tests. Overall, the study findings reveal a high prevalence (58.3%) of substandard anti-malarial drugs in the region. The stated percent of the samples had failed in one or more of the quality test parameters assessed in this study. CONCLUSION: The study findings reveal a high prevalence (58.3%) of substandard anti-malarial drugs in the region. Only a quarter were registered and 38% of the unregistered products failed the quality tests. Hence, the national, regional medicine regulatory bodies and other stake holders should perform the required roles to circumvent presence of Substandard and Falsified (SF) anti-malarial drugs in the study sites.

Synthetic vectors for activating the driving axis of ferroptosis.

Ferroptosis is a promising strategy for cancer therapy, with numerous inhibitors of its braking axes under investigation as potential drugs. However, few studies have explored the potential of activating the driving axes to induce ferroptosis. Herein, phosphatidylcholine peroxide decorating liposomes (LIPPCPO) are synthesized to induce ferroptosis by targeting divalent metal transporter 1 (DMT1). LIPPCPO is found to boost lysosomal Fe2+ efflux by inducing cysteinylation of lysosomal DMT1, resulting in glutathione peroxidase 4 (GPX4) suppression, glutathione depletion and ferroptosis in breast cancer cells and xenografts. Importantly, LIPPCPO induced ferroptotic cell death is independent of acquired resistance to radiation, chemotherapy, or targeted agents in 11 cancer cell lines. Furthermore, a strong synergistic ferroptosis effect is observed between LIPPCPO and an FDA-approved drug, artesunate, as well as X rays. The formula of LIPPCPO encapsulating artesunate significantly inhibits tumor growth and metastasis and improves the survival rate of breast cancer-bearing female mice. These findings provide a distinct strategy for inducing ferroptosis and highlight the potential of LIPPCPO as a vector to synergize the therapeutic effects of conventional ferroptosis inducers.

Parasite clearance and protection from Plasmodium falciparum infection (PCPI): a three-arm, parallel, double-blinded, placebo-controlled, randomised trial of presumptive sulfadoxine-pyrimethamine versus sulfadoxine-pyrimethamine plus amodiaquine versus artesunate monotherapy among asymptomatic children 3-5 years of age in Cameroon.

BACKGROUND: The World Health Organization 2022 malaria chemoprevention guidelines recommend providing a full course of antimalarial treatment at pre-defined intervals, regardless of malaria status to prevent illness among children resident in moderate to high perennial malaria transmission settings as perennial malaria chemoprevention (PMC) with sulfadoxine-pyrimethamine (SP). The dhps I431V mutation circulating in West Africa has unknown effect on SP protective efficacy. METHODS: This protocol is for a three-arm, parallel, double-blinded, placebo-controlled, randomised trial in Cameroon among children randomly assigned to one of three directly-observed treatment groups: (i) Group 1 (n = 450) receives daily artesunate (AS) placebo on days - 7 to -1, then active SP plus placebo amodiaquine (AQ) on day 0, and placebo AQ on days 1 and 2; (ii) Group 2 (n = 250) receives placebo AS on days - 7 to -1, then active SP and AQ on day 0, and active AQ on days 1 and 2; and (iii) Group 3 (n = 200) receives active AS on days - 7 to -1, then placebo SP on day 0 and placebo AQ on days 0 to 2. On days 0, 2, 5, 7, and thereafter weekly until day 28, children provide blood for thick smear slides. Dried blood spots are collected on the same days and weekly from day 28 to day 63 for quantitative polymerase chain reaction (qPCR) and genotype analyses. DISCUSSION: Our aim is to quantify the chemopreventive efficacy of SP, and SP plus AQ, and measure the effect of the parasite genotypes associated with SP resistance on parasite clearance and protection from infection when exposed to SP chemoprevention. We will report unblinded results including: (i) time-to-parasite clearance among SP and SP plus AQ recipients who were positive on day 0 by qPCR and followed to day 63; (ii) mean duration of SP and SP plus AQ protection against infection, and (iii) mean duration of symptom-free status among SP and SP plus AQ recipients who were parasite free on day 0 by qPCR. Our study is designed to compare the 28-day follow-up of the new WHO malaria chemoprevention efficacy study protocol with extended follow-up to day 63. TRIAL REGISTRATION: ClinicalTrials.gov NCT06173206; 15/12/2023.

[Severe complicated malaria caused by Plasmodium falciparum in a female traveler returning from Zanzibar]. / Schwere komplizierte Malaria durch Plasmodium falciparum bei einer Reiserückkehrerin aus Sansibar.

MEDICAL HISTORY: A 25-year-old female outpatient presenting with fever and micro-hematuria was treated for urinary tract infection. Her condition worsened over 3 days at home. After experiencing multiple falls caused by leg weakness and mental confusion, she was admitted to a hospital with high fever. DIAGNOSTICS: Initial laboratory findings showed hemolytic anemia, pancytopenia, and acute kidney injury, suggesting hemolytic uremic syndrome. However, a detailed fever evaluation revealed her recent return from Afrika. This prompted a malaria test, which confirmed Plasmodium falciparum infection with 80 % parasitemia. THERAPY AND PROGRESS: Despite the quick reduction of parasitemia following treatment with intravenous administered artesunate and oral Artemether-Lumefantrine, her condition worsened, leading to a septic shock. This required renal replacement and kinetic ventilation therapy, as well as blood transfusions due to persistent hemolysis until the laboratory values normalized after 48 days post-admission. CONCLUSION: The evaluation of fever is often challenging, but most often a detailed patient history is key to early diagnosis and treatment preventing deathly outcomes in severe cases.

Artesunate attenuates osteoarthritis in mice by promoting MTA1 transcription through a USP7/FoxO1 axis.

Artesunate (ART) is a derivative of artemisinin and has anti-inflammatory, anti-tumor, and anti-angiogenic properties. Although ART has been implicated in osteoarthritis (OA), the mechanism needs to be further dissected. Here, we explored the effects of ART on the development of OA and the underlying mechanism using destabilization of the medial meniscus (DMM) surgical instability model. Mice with OA were developed using DMM and treated with ART. The pathological morphology of knee joint tissues was examined, and the degeneration of joint cartilage was assessed. Mouse knee chondrocytes were isolated and induced with IL-1ß, followed by ART treatment. ART alleviates OA in mice by elevating ubiquitin carboxyl-terminal hydrolase 7 (USP7) expression, and USP7 inhibitor (P22077) treatment mitigated the protective effects of ART on chondrocytes. We also showed that USP7 mediated the deubiquitination of forkhead box protein O1 (FoxO1), while FoxO1 alleviated chondrocyte injury. In addition, FoxO1 promoted metastasis-associated protein MTA1 (MTA1) transcription, and downregulation of MTA1 exacerbated chondrocyte injury. Our study identifies that USP7/FoxO1/MTA1 is a key signaling cascade in the treatment of ART on OA.

Design, synthesis and biological evaluation of artesunate-Se derivatives as anticancer agents by inducing GPX4-mediated ferroptosis.

A series of organoselenium compounds based on the hybridization of artesunate (ART) scaffolds and Se functionalities (-SeCN and -SeCF3) were synthesized. The redox properties of artesunate-SeCN and artesunate-SeCF3 derivatives were conducted by 2, 2-didiphenyl-1-picrylhydrazyl (DPPH), and the results showed that compounds 2c, 2f and 3e have a good free radical scavenging activity. Their cytotoxicity was evaluated against four types of cancer cell lines, SW480 (human colon adenocarcinoma cells), HCT116 (human colorectal adenocarcinoma cells), HepG2 (human hepatocellular carcinoma cells), MCF-7 (human breast cancer cells). The MTT results showed that compared with ART and 5-FU, compound 2c exhibited potent in vitro antiproliferative activity in SW480, HCT116, and MCF-7 cancer cell lines, and was thus chose for further antitumor mechanism investigation. The antitumor mechanism study revealed that compound 2c induced ferroptosis in HCT116 cells by inhibiting the expression of GPX4 protein, accompanying by the up-regulation of intracellular ROS levels. Mitochondria in HCT116 cells exhibit depolarization of mitochondrial membrane potential (MMP) and ultrastructural changes in morphology, which indicated that 2c resulted in mitochondrial dysfunction and ferroptosis. Moreover, 2c could increase the levels of lipid peroxidation and ferrous ion, which further confirm that compound 2c may exert its antitumor effect through ferroptosis. Overall, these results suggest that the artesunate-Se candidates could provide promising new lead derivatives for further potential anticancer drug development.

Artesunate induces HO-1-mediated cell cycle arrest and senescence to protect against ocular fibrosis.

Recent research found artesunate could inhibit ocular fibrosis; however, the underlying mechanisms are not fully known. Since the ocular fibroblast is the main effector cell in fibrosis, we hypothesized that artesunate may exert its protective effects by inhibiting the fibroblasts proliferation. TGF-ß1-induced ocular fibroblasts and glaucoma filtration surgery (GFS)-treated rabbits were used as ocular fibrotic models. Firstly, we analyzed fibrosis levels by assessing the expression of fibrotic marker proteins, and used Ki67 immunofluorescence, EdU staining, flow cytometry to determine cell cycle status, and SA-ß-gal staining to assess cellular senescence levels. Then to predict target genes and pathways of artesunate, we analyzed the differentially expressed genes and enriched pathways through RNA-seq. Western blot and immunohistochemistry were used to detect the pathway-related proteins. Additionally, we validated the dependence of artesunate's effects on HO-1 expression through HO-1 siRNA. Moreover, DCFDA and MitoSOX fluorescence staining were used to examine ROS level. We found artesunate significantly inhibits the expression of fibrosis-related proteins, induces cell cycle arrest and cellular senescence. Knocking down HO-1 in fibroblasts with siRNA reverses these regulatory effects of artesunate. Mechanistic studies show that artesunate significantly inhibits the activation of the Cyclin D1/CDK4-pRB pathway, induces an increase in cellular and mitochondrial ROS levels and activates the Nrf2/HO-1 pathway. In conclusion, the present study identifies that artesunate induces HO-1 expression through ROS to activate the antioxidant Nrf2/HO-1 pathway, subsequently inhibits the cell cycle regulation pathway Cyclin D1/CDK4-pRB in an HO-1-dependent way, induces cell cycle arrest and senescence, and thereby resists periorbital fibrosis.

In vitro assessment of the anti-adenoviral activity of artemisinin and its derivatives.

Adenoviral infections, particularly in children, remain a significant public health issue with no approved targeted treatments. Artemisinin and its derivatives, well-known for their use in malaria treatment, have shown antiviral activities in recent studies. However, their efficacy against human adenovirus (HAdV) remains unexplored. This study aimed to assess the activity of artemisinin and its derivatives against HAdV infection in vitro using cell lines and primary cells. Our data revealed that artemisinin exhibited dose-dependent anti-HAdV activity with no apparent cytotoxicity over a wide concentration range. Mechanistically, artemisinin did not affect viral attachment or entry into target cells, nor the viral genome entry into cell nucleus. Instead, it inhibited HAdV through suppression of viral DNA replication. Comparative analysis with its derivatives, artesunate and artemisone, showed distinct cytotoxicity and anti-adenoviral profiles, with artemisone showing superior efficacy and lower toxicity. Further validation using a primary airway epithelial cell model confirmed the anti-adenoviral activity of both artemisinin and artemisone against different virus strains. Together, our findings suggest that artemisinin and its derivatives may be promising candidates for anti-HAdV treatment.

Inter-Species Pharmacokinetic Modeling and Scaling for Drug Repurposing of Pyronaridine and Artesunate.

Even though several new targets (mostly viral infection) for drug repurposing of pyronaridine and artesunate have recently emerged in vitro and in vivo, inter-species pharmacokinetic (PK) data that can extend nonclinical efficacy to humans has not been reported over 30 years of usage. Since extrapolation of animal PK data to those of humans is essential to predict clinical outcomes for drug repurposing, this study aimed to investigate inter-species PK differences in three animal species (hamster, rat, and dog) and to support clinical translation of a fixed-dose combination of pyronaridine and artesunate. PK parameters (e.g., steady-state volume of distribution (Vss), clearance (CL), area under the concentration-time curve (AUC), mean residence time (MRT), etc.) of pyronaridine, artesunate, and dihydroartemisinin (an active metabolite of artesunate) were determined by non-compartmental analysis. In addition, one- or two-compartment PK modeling was performed to support inter-species scaling. The PK models appropriately described the blood concentrations of pyronaridine, artesunate, and dihydroartemisinin in all animal species, and the estimated PK parameters in three species were integrated for inter-species allometric scaling to predict human PKs. The simple allometric equation (Y = a × Wb) well explained the relationship between PK parameters and the actual body weight of animal species. The results from the study could be used as a basis for drug repurposing and support determining the effective dosage regimen for new indications based on in vitro/in vivo efficacy data and predicted human PKs in initial clinical trials.

Artesunate inhibits vasculogenic mimicry in choroidal melanoma through HIF-1 α/ VEGF/PDGF pathway.

Choroidal melanoma (CM), a highly metastatic eye tumor, exhibits vasculogenic mimicry (VM) facilitated by hypoxia-induced angiogenesis. This study explored the inhibitory impact of the anti-malarial drug Artesunate (ART) on CM VM through modulation of the HIF-1α/VEGF/PDGF pathway. Immunohistochemistry (IHC) confirmed VM in CM with elevated VEGF and PDGF expression. Hypoxia promoted CM proliferation, upregulating HIF-1α, VEGF and PDGF. VEGF and PDGF enhanced CM migration, invasion and VM, with HIF-1α playing a crucial role. ART mitigated VM formation by suppressing the HIF-1α/VEGF/PDGF pathway, highlighting its potential as an anti-tumor agent in CM.

Therapeutic efficacy of pyronaridine-artesunate (Pyramax) in treating Plasmodium vivax malaria in the central highlands of Vietnam.

The emergence and spread of chloroquine-resistant Plasmodium vivax have necessitated the assessment of alternative blood schizonticidal drugs. In Vietnam, chloroquine-resistant P. vivax malaria has been reported. In an open-label, single-arm trial, the safety, tolerability, and efficacy of pyronaridine-artesunate (Pyramax, PA) was evaluated in Dak Nong province, Vietnam. A 3-day course of PA was administered to adults and children (≥20 kg) infected with P. vivax. Patients also received primaquine (0.25 mg/kg daily for 14 days). PA was well tolerated with transient asymptomatic increases in liver transaminases. The per-protocol proportion of patients with day 42 PCR-unadjusted adequate clinical and parasitological response was 96.0% (95% CI, 84.9%-99.0%, n = 48/50). The median parasite clearance time was 12 h (range, 12-36 h), with a median fever clearance time of 24 h (range, 12-60 h). Single nucleotide polymorphisms (SNPs) as potential genetic markers of reduced drug susceptibility were analyzed in three putative drug resistance markers, Pvcrt-o, Pvmdr1, and PvK12. Insertion at position K10 of the Pvcrt-o gene was found in 74.6% (44/59) of isolates. Pvmdr1 SNPs at Y976F and F1076L were present in 61% (36/59) and 78% (46/59), respectively. Amplification of Pvmdr1 gene (two copies) was found in 5.1% (3/59) of parasite samples. Only 5.1% (3/59) of isolates had mutation 552I of the PvK12 gene. Overall, PA rapidly cleared P. vivax blood asexual stages and was highly efficacious in treating vivax malaria, with no evidence of artemisinin resistance found. PA provides an alternative to chloroquine treatment for vivax malaria in Vietnam. CLINICAL TRIALS: This study is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12618001429246.

Hla protein expression and artesunate prevented mice from further damage caused by Staphylococcus aureus pneumonia.

The laboratory standard MRSA strain WHO-2 and clinical isolate S1 were used to establish a pneumonia infection model. The results showed that methicillin increased the expression of Hla and PVL protein at subminimum inhibitory concentration, while artesunate decreased the secretion of Hla and PVL protein. Artesunate alone reduced hemolysin expression and reversed methicillin-induced increases in Hla and PVL proteins. In addition, the study found that the combination of artesunate and methicillin had the best therapeutic effect, with survival rates of 70 % and 40 % at seven days, respectively (corresponding to the WHO-2 and S1 strains). The combination treatment was able to reduce cell mortality, showing a 65 % and 46 % reduction in cell mortality, respectively. The study also found that the combination therapy decreased the expression of alpha-hemolysin and pantone valentin leukin in the culture medium and significantly reduced the activation of NF-kB. This is caused by a significant decrease in the expression of inflammatory factors.

Transmission-blocking activities of artesunate, chloroquine, and methylene blue on Plasmodium vivax gametocytes.

Plasmodium vivax is now the main cause of malaria outside Africa. The gametocytocidal effects of antimalarial drugs are important to reduce malaria transmissibility, particularly in low-transmission settings, but they are not well characterized for P. vivax. The transmission-blocking effects of chloroquine, artesunate, and methylene blue on P. vivax gametocytes were assessed. Blood specimens were collected from patients presenting with vivax malaria, incubated with or without the tested drugs, and then fed to mosquitos from a laboratory-adapted colony of Anopheles dirus (a major malaria vector in Southeast Asia). The effects on oocyst and sporozoite development were analyzed under a multi-level Bayesian model accounting for assay variability and the heterogeneity of mosquito Plasmodium infection. Artesunate and methylene blue, but not chloroquine, exhibited potent transmission-blocking effects. Gametocyte exposures to artesunate and methylene blue reduced the mean oocyst count 469-fold (95% CI: 345 to 650) and 1,438-fold (95% CI: 970 to 2,064), respectively. The corresponding estimates for the sporozoite stage were a 148-fold reduction (95% CI: 61 to 470) and a 536-fold reduction (95% CI: 246 to 1,311) in the mean counts, respectively. In contrast, high chloroquine exposures reduced the mean oocyst count only 1.40-fold (95% CI: 1.20 to 1.64) and the mean sporozoite count 1.34-fold (95% CI: 1.12 to 1.66). This suggests that patients with vivax malaria often remain infectious to anopheline mosquitos after treatment with chloroquine. Use of artemisinin combination therapies or immediate initiation of primaquine radical cure should reduce the transmissibility of P. vivax infections.

Artesunate induces melanoma cell ferroptosis and augments antitumor immunity through targeting Ido1.

Artesunate (ART), a natural product isolated from traditional Chinese plant Artemisia annua, has not been extensively explored for its anti-melanoma properties. In our study, we found that ART inhibited melanoma cell proliferation and induced melanoma cell ferroptosis. Mechanistic study revealed that ART directly targets Ido1, thereby suppressing Hic1-mediated transcription suppression of Hmox1, resulting in melanoma cell ferroptosis. In CD8+ T cells, ART does not cause cell ferroptosis due to the low expression of Hmox1. It also targets Ido1, elevating tryptophan levels, which inhibits NFATc1-mediated PD1 transcription, consequently activating CD8+ T cells. Our study uncovered a potent and synergistic anti-melanoma efficacy arising from ART-induced melanoma cell ferroptosis and concurrently enhancing CD8+ T cell-mediated immune response both in vivo and in vitro through directly targeting Ido1. Our study provides a novel mechanistic basis for the utilization of ART as an Ido1 inhibitor and application in clinical melanoma treatment.

Based on NF-κB and Notch1/Hes1 Signaling Pathways, the Mechanism of Artesunate on Inflammation in Osteoporosis in Ovariectomized Rats was Investigated.

BACKGROUND: Artesunate (ART) has the potential to modulate the nuclear factor kappa B (NF-κB) and Notch1/Hes1 signaling pathways, which play crucial roles in the pathogenesis of osteoporosis. This study aims to explore whether ART participates in the progression of osteoporosis by regulating these signaling pathways. METHODS: In the in vitro experiments, we treated bone marrow mesenchymal stem cells (BMSCs) with different concentrations of ART (0, 3, 6, 12 µM) and evaluated osteogenic differentiation using alkaline phosphatase staining (ALP) and alizarin red S staining (ARS) staining. The expression levels of osteocalcin (OCN), RUNT-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), and receptor activator of the nuclear factor kappa ligand (RANKL) were detected by real-time quantitative PCR (RT-qPCR). The effects of ART on NF-κB p65 and Notch1 protein expression were analyzed by Western blot (WB) and immunofluorescence (IF). In the in vivo experiments, a postmenopausal osteoporosis rat model was established via ovariectomy. Bone tissue pathological injury was evaluated using hematoxylin eosin (HE) staining. Serum ALP levels were measured using a kit, bone density was determined by dual-energy X-ray absorptiometry, and serum levels of bone gla protein (BGP), OPG, RANKL, tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and IL-1ß were measured by enzyme-linked immunosorbent assay (ELISA). Additionally, the expression of NF-κB p65 and Notch1 in tissues was assessed by immunohistochemistry. RESULTS: In vitro experiments revealed that compared to the control group, ART dose-dependently promoted BMSCs proliferation and enhanced their osteogenic differentiation capability. The expression of OCN, RUNX2, and OPG significantly increased in the ART-treated group, while RANKL expression decreased significantly (p < 0.05). ART significantly inhibited the expression of NF-κB p65 and Notch1/Hes1 signaling pathway proteins (p < 0.05). Compared to ART treatment alone, combined treatment with ART and phorbol myristate acetate (PMA) or valproic acid (VPA) resulted in increased expression of NF-κB p65 and Notch1 proteins and decreased osteogenic differentiation capability (p < 0.05). In vivo experiments showed that in rats treated with ART, bone damage was significantly reduced, bone density and mineral content were restored considerably, and the expression of inflammatory factors (TNF-α, IL-6, IL-1ß) decreased significantly (p < 0.05). Additionally, ART treatment significantly reduced the expression of NF-κB p65 and Notch1 proteins, increased OPG expression, and decreased BGP and RANKL levels (p < 0.05). CONCLUSION: In summary, ART facilitates the osteogenic differentiation of BMSCs by inhibiting the NF-κB and Notch1/Hes1 signaling pathways, thereby exerting significant protective effects against osteoporosis.

Indigenous emergence and spread of kelch13 C469Y artemisinin-resistant Plasmodium falciparum in Uganda.

Artemisinin-based combination therapies (ACTs) were introduced as the standard of care for uncomplicated malaria in Africa almost two decades ago. Recent studies in East Africa have reported a gradual increase in kelch13 (k13) mutant parasites associated with reduced artesunate efficacy. As part of the Community Access to Rectal Artesunate for Malaria project, we collected blood samples from 697 children with signs of severe malaria in northern Uganda between 2018 and 2020, before and after the introduction of rectal artesunate (RAS) in 2019. K13 polymorphisms were assessed, and parasite editing and phenotyping were performed to assess the impact of mutations on parasite resistance. Whole-genome sequencing was performed, and haplotype networks were constructed to determine the geographic origin of k13 mutations. Of the 697 children, 540 were positive for Plasmodium falciparum malaria by PCR and were treated with either RAS or injectable artesunate monotherapy followed in most cases by ACT. The most common k13 mutation was C469Y (6.7%), which was detected more frequently in samples collected after RAS introduction. Genome editing confirmed reduced in vitro susceptibility to artemisinin in C469Y-harboring parasites compared to wild-type controls (P < 0.001). The haplotypic network showed that flanking regions of the C469Y mutation shared the same African genetic background, suggesting a single and indigenous origin of the mutation. Our data provide evidence of selection for the artemisinin-resistant C469Y mutation. The realistic threat of multiresistant parasites emerging in Africa should encourage careful monitoring of the efficacy of artemisinin derivatives and strict adherence to ACT treatment regimens.

Thiol-Amino Bifunctional Metal-Organic-Framework-Based Membrane Regulating Hydrophobic Sites for Selective Separation of Artesunate.

The selective separation and purification of artesunate (ARU) and artemisinin (ART) using zirconium-based metal-organic frameworks (MOF), especially UiO-66 MOF, are receiving increasing attention. In this study, tunable "hydrophobic" sites of thiol (-SH) were introduced to amino-functionalized MOFs (UiO-66-NH2) to fabricate a thiol-amino bifunctional UiO-66/polyvinylidene fluoride (PVDF)-blended membrane (S1-UiO/PVDF-DPIM) via the delayed-phase-inversion method for selective separation of ARU/ART. The adsorption results indicated that the modification of UiO-66-NH2 with thiol can indeed increase the ARU adsorption. The thiol-functional MOF (S1-UiO-66-NH2) was chosen as the optimal thiol-amino bifunctional MOF, as it possessed the maximum ARU adsorption capacity (111.14 mg g-1) and the highest selective-separation factor (α = 51.84). The ATR FT-IR dynamic spectrum disclosed the recognition mechanism, indicating that incorporating thiol groups into a hydrophilic MOF as hydrophobic sites can boost adsorption efficiency. Moreover, the static-selective permeation results showed that the S1-UiO/PVDF-DPIM preferentially transfers ARU when mixed with ART, even achieving complete ARU/ART separation. The most crucial aspect was the introduction of a hydrophobic core of -SH and new spontaneously formed disulfide bonds to S1-UiO/PVDF-DPIM, creating alternated hydrogen bonds and hydrophobic interactions. This work provides an alternative strategy to prepare hydrophobic-hydrophilic MOF-based membranes for the highly efficient and selective separation of complex analogue systems.