Palmitoylation of PKCδ by ZDHHC5 in hypothalamic microglia presents as a therapeutic target for fatty liver disease.

The hypothalamus plays a fundamental role in controlling lipid metabolism through neuroendocrine signals. However, there are currently no available drug targets in the hypothalamus that can effectively improve human lipid metabolism. In this study, we found that the antimalarial drug artemether (ART) significantly improved lipid metabolism by specifically inhibiting microglial activation in the hypothalamus of high-fat diet-induced mice. Mechanically, ART protects the thyrotropin-releasing hormone (TRH) neurons surrounding microglial cells from inflammatory damage and promotes the release of TRH into the peripheral circulation. As a result, TRH stimulates the synthesis of thyroid hormone (TH), leading to a significant improvement in hepatic lipid disorders. Subsequently, we employed a biotin-labeled ART chemical probe to identify the direct cellular target in microglial cells as protein kinase Cδ (PKCδ). Importantly, ART directly targeted PKCδ to inhibit its palmitoylation modification by blocking the binding of zinc finger DHHC-type palmitoyltransferase 5 (ZDHHC5), which resulted in the inhibition of downstream neuroinflammation signaling. In vivo, hypothalamic microglia-specific PKCδ knockdown markedly impaired ART-dependent neuroendocrine regulation and lipid metabolism improvement in mice. Furthermore, single-cell transcriptomics analysis in human brain tissues revealed that the level of PKCδ in microglia positively correlated with individuals who had hyperlipemia, thereby highlighting a clinical translational value. Collectively, these data suggest that the palmitoylation of microglial PKCδ in the hypothalamus plays a role in modulating peripheral lipid metabolism through hypothalamus-liver communication, and provides a promising therapeutic target for fatty liver diseases.

Artemisinins: Promising drug candidates for the treatment of autoimmune diseases.

Autoimmune diseases are characterized by the immune system's attack on one's own tissues which are highly diverse and diseases differ in severity, causing damage in virtually all human systems including connective tissue (e.g., rheumatoid arthritis), neurological system (e.g., multiple sclerosis) and digestive system (e.g., inflammatory bowel disease). Historically, treatments normally include pain-killing medication, anti-inflammatory drugs, corticosteroids, and immunosuppressant drugs. However, given the above characteristics, treatment of autoimmune diseases has always been a challenge. Artemisinin is a natural sesquiterpene lactone initially extracted and separated from Chinese medicine Artemisia annua L., which has a long history of curing malaria. Artemisinin's derivatives such as artesunate, dihydroartemisinin, artemether, artemisitene, and so forth, are a family of artemisinins with antimalarial activity. Over the past decades, accumulating evidence have indicated the promising therapeutic potential of artemisinins in autoimmune diseases. Herein, we systematically summarized the research regarding the immunoregulatory properties of artemisinins including artemisinin and its derivatives, discussing their potential therapeutic viability toward major autoimmune diseases and the underlying mechanisms. This review will provide new directions for basic research and clinical translational medicine of artemisinins.

In silico modeling revealed phytomolecules derived from Cymbopogon citratus (DC.) leaf extract as promising candidates for malaria therapy.

The emergence of varying levels of resistance to currently available antimalarial drugs significantly threatens global health. This factor heightens the urgency to explore bioactive compounds from natural products with a view to discovering and developing newer antimalarial drugs with novel mode of actions. Therefore, we evaluated the inhibitory effects of sixteen phytocompounds from Cymbopogon citratus leaf extract against Plasmodium falciparum drug targets such as P. falciparum circumsporozoite protein (PfCSP), P. falciparum merozoite surface protein 1 (PfMSP1) and P. falciparum erythrocyte membrane protein 1 (PfEMP1). In silico approaches including molecular docking, pharmacophore modeling and 3D-QSAR were adopted to analyze the inhibitory activity of the compounds under consideration. The molecular docking results indicated that a compound swertiajaponin from C. citratus exhibited a higher binding affinity (-7.8 kcal/mol) to PfMSP1 as against the standard artesunate-amodiaquine (-6.6 kcal/mol). Swertiajaponin also formed strong hydrogen bond interactions with LYS29, CYS30, TYR34, ASN52, GLY55 and CYS28 amino acid residues. In addition, quercetin another compound from C. citratus exhibited significant binding energies -6.8 and -8.3 kcal/mol with PfCSP and PfEMP1, respectively but slightly lower than the standard artemether-lumefantrine with binding energies of -7.4 kcal/mol against PfCSP and -8.7 kcal/mol against PfEMP1. Overall, the present study provides evidence that swertiajaponin and other phytomolecules from C. citratus have modulatory properties toward P. falciparum drug targets and thus may warrant further exploration in early drug discovery efforts against malaria. Furthermore, these findings lend credence to the folkloric use of C. citratus for malaria treatment.Communicated by Ramaswamy H. Sarma.

[Microbial transformation of artemisinin and its derivatives].

Microbial transformation is an efficient enzymatic approach for the structural modification of exogenous compounds to obtain derivatives. Compared with traditional chemical synthesis, the microbial transformation has in fact the undoubtable advantages of strong region-and stereo-selectivity, and a low environmental and economic impact on the production process, which can achieve the reactions challenging to chemical synthesis. Because microbes are equipped with a broad-spectrum of enzymes and therefore can metabolize various substrates, they are not only a significant route for obtaining novel active derivatives, but also an effective tool for mimicking mammal metabolism in vitro. Artemisinin, a sesquiterpene with a peroxy-bridged structure serving as the main active functional group, is a famous antimalarial agent discovered from Artemisia annua L. Some sesquiterpenoids, such as dihydroartemisinin, artemether, and arteether, have been developed on the basis of artemisinin, which have been successfully marketed and become the first-line antimalarial drugs recommended by WHO. As revealed by pharmacological studies, artemisinin and its derivatives have exhibited extensive biological activities, including antimalarial, antitumor, antiviral, anti-inflammatory, and immunomodulatory. As an efficient approach for structural modification, microbial transformation of artemisinin and its derivatives is an increasingly popular strategy that attracts considerable attention recently, and numerous novel derivatives have been discovered. Herein, this paper reviewed the microbial transformation of artemisinin and its artemisinin, including microbial strains, culture conditions, product isolation and yield, and biological activities, and summarized the advances in microbial transformation in obtaining active derivatives of artemisinin and the simulation of in vivo metabolism of drugs.

Artemether ameliorates adriamycin induced cardiac atrophy in mice.

Adriamycin is a widely used and effective antitumor drug; however, its application is limited by various side effects, including irreversible cardiotoxicity. The central role of cardiac atrophy in Adriamycin­induced cardiotoxicity has been revealed; however, the underlying mechanism of this process remains unclear. Artemether is a well­known Chinese herbal medicine, and its pharmacological action is related to the regulation of mitochondrial function and redox status. The present study determined the effects of artemether on Adriamycin­induced cardiotoxicity and investigated the underlying mechanisms. After mouse model establishment and artemether intervention, experimental methods including pathological staining, immunohistochemistry, immunofluorescence, immunoblotting, ELISA and reverse transcription­quantitative PCR were used to evaluate the therapeutic effect. The results demonstrated that artemether prevented Adriamycin­induced cardiac atrophy and recovered the intercombination of connexin 43 and N­cadherin at the intercalated discs. Artemether also regulated the autophagy pathway and restored the unbalanced ratio of Bax and Bcl­2 in myocardial cells. In addition, the increased serum H2O2 levels after Adriamycin exposure were significantly decreased by artemether, and the mitochondrial alterations and redox imbalance in myocardial cells were also improved to varying degrees. In summary, the findings of the present study provide reliable evidence that artemether could ameliorate cardiac atrophy induced by Adriamycin. This therapeutic approach may be translated to the clinic for preventing drug­induced heart diseases.

Vitamin C-rich juice co-administration with artemether-lumefantrine ameliorates oxido-inflammatory responses in Plasmodium berghei-infected mice.

This study investigated the effects of co-administration of a commercial juice rich in vitamin C (Vit C) on the antimalarial efficacy of artemether-lumefantrine (AL) in Plasmodium berghei-infected mice. Fifty Balb/c mice were infected with Plasmodium berghei NK65 strain from a donor mouse. Parasitemia was established after 72 h. Animals were grouped into 6 (n = 10) and treated daily for 3 days with normal saline, chloroquine, artemether-lumefantrine (AL), AL plus 50% commercial juice (CJ), and AL plus 50% Vit C supplementation in drinks ad libitum, respectively. Body weight, parasitemia levels, and mean survival time were determined. Tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), nitrite, malondialdehyde, reduced glutathione (GSH), catalase, and superoxide dismutase (SOD) were determined in the serum and liver tissues. Spleen histopathological changes were determined by H&E staining. Parasitemia was cleared by administration of AL and was not affected by Vit C and CJ supplementation. Vit C significantly prevented body weight reduction in AL-treated mice. CJ and Vit C supplementation to AL-treated mice significantly improved survival proportion compared with AL alone animals. Vit C and CJ supplementation significantly improved reduction of TNF-α, IL-6, and malondialdehyde, and increased GSH, CAT, and SOD in AL-treated mice. Spleen cell degeneration and presence of malaria pigment were reduced in AL-treated animals. The results suggest that ad libitum co-administration of commercial juice and vitamin C with artemether-lumefantrine does not impair its antimalarial efficacy but rather improved antioxidant and anti-inflammatory effects in mice.

Optimization of HPLC-MS/MS method for determination of antimalarial adulterants in herbal products.

The use of herbal products is booming all over the world because of being believed as safer than conventional drugs and free of side effects. However, there are untrustworthy manufacturers who adulterate herbal products by adding conventional drugs which might eventually lead to microbial resistance and herb-to-drug interactions. There is a need to develop methods for detecting adulterants in herbal products. A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for simultaneous identification and determination of conventional antimalarials (chloroquine, quinine, sulfadoxine, pyrimethamine, mefloquine, lumefantrine, amodiaquine, artemisinin, dihydroartemisinin, artesunate and artemether) in herbal products was developed. Stable isotopically labelled compounds (artemether-d3, quindine-d3, and sulfadoxine-d3) were used as internal standards (ISs) for quantitative analysis. Extraction of analytes was performed using methanol: water: formic acid (90:10:0.1, v/v) and chromatographic separation was done in a gradient mode using mobile phase A: Ultrapure water containing 0.1% formic acid and 1 mM ammonium formate and mobile phase B: Acetonitrile/methanol (50:50) containing 0.1% formic acid and 1 mM ammonium formate. The calibration curves were linear (r2 ≥ 0.991) over the range of 0.001-0.3 µg mL-1 for all compounds. The limit of detection (LOD) ranged from 0.002 to 0.02 µg mL-1 while the limit of quantification (LOQ) ranged from 0.006 to 0.08 µg mL-1. Accuracy, expressed as recovery of spiked herbal products ranged from 52 to 128%. The precision, expressed as percent relative standard deviation (%RSD) at two concentration levels, ranged from 1.0 to 13.8%. The matrix effect expressed as the matrix factor (MF) ranged from 0.77 to 0.97. The developed method was used to identify and quantify conventional antimalarials in herbal product samples from Tanzania. Ten out of 50 herbal products were found to contain amodiaquine, sulfadoxine, pyrimethamine, mefloquine, dihydroartemisinin, artemether and lumefantrine. The developed method is considered a valuable tool for getting a better understanding of the adulteration of conventional antimalarials in herbal products.

Drug-Drug Interactions of Artemisinin-Based Combination Therapies in Malaria Treatment: A Narrative Review of the Literature.

Artemisinin is an antimalarial compound derived from the plant Artemisia annua L., also known as sweet wormwood. According to the World Health Organization, artemisinin-based combination therapy (ACT) is an essential treatment for malaria, specifically Plasmodium falciparum, which accounts for most malaria-related mortality. ACTs used to treat uncomplicated malaria include artemether-lumefantrine, artesunate-amodiaquine, artesunate-mefloquine, artesunate-sulphadoxine-pyrimethamine, and dihydroartemisinin-piperaquine. Although the mechanism of action and clinical capabilities of artemisinin in malaria treatment are widely known, more information on the potential for drug interactions needs to be further investigated. Some studies show pharmacokinetic and pharmacodynamic drug interactions with HIV antiviral treatment but few studies have been conducted on most other drug classes. Based on known genotypes of cytochrome P450 (CYP) enzymes, CYP2B6 and CYP3A are primarily involved in the metabolism of artemisinin and its derivatives. Reduced functions in these enzymes can lead to subtherapeutic concentrations of the active metabolite, dihydroartemisinin, that may cause treatment failure, which has been shown in some studies with cardiovascular, antibiotic, and antiparasitic drugs. Although the clinical importance remains unclear to date, clinicians should be aware of potential drug-drug interactions and monitor patients on ACT closely.

Exploring the Potential Mechanism of Artemisinin and Its Derivatives in the Treatment of Osteoporosis Based on Network Pharmacology and Molecular Docking.

Objective: This study is aimed at predicting and contrasting the mechanisms of artemisinin (ARS), dihydroartemisinin (DHA), artesunate (ART), artemether (ARM), and arteether (ARE) in the treatment of osteoporosis (OP) using network pharmacology and molecular docking. Methods: The targets of ARS, DHA, ART, ARM, and ARE were obtained from the SwissTargetPrediction. The targets related to OP were obtained from the TTD, DrugBank, Genecards, and DisGeNet databases. Then, the anti-OP targets of ARS, DHA, ART, ARM, and ARE were obtained and compared using the Venn diagram. Afterward, the protein-protein interaction (PPI) networks were built using the STRING database, and Cytoscape was used to select hub targets. Moreover, molecular docking validated the binding association between five molecules and hub targets. Finally, GO enrichment and KEGG pathway enrichment were conducted using the DAVID database. The common pathways of five molecules were analysed. Results: A total of 28, 37, 36, 27, and 33 anti-OP targets of ARS, DHA, ART, ARM, and ARE were acquired. EGFR, EGFR, CASP3, MAPK8, and CASP3 act as the top 1 anti-OP targets of ARS, DHA, ART, ARM, and ARE, respectively. MAPK14 is the common target of five molecules. All five molecules can bind well with these hubs and common targets. Meanwhile, functional annotation showed that MAPK, Serotonergic synapse, AMPK, prolactin, and prolactin signaling pathways are the top 1 anti-OP pathway of ARS, DHA, ART, ARM, and ARE, respectively. IL-17 signaling pathway and prolactin signaling pathway are common anti-OP pathways of five molecules. Besides, GO enrichment showed five biological processes and three molecular functions are common anti-OP mechanisms of five molecules. Conclusion: ARS, DHA, ART, ARM and ARE can treat OP through multi-targets and multi pathways, respectively. All five molecules can treat OP by targeting MAPK14 and acting on the IL-17 and prolactin signaling pathways.

Artemether, Artesunate, Arteannuin B, Echinatin, Licochalcone B and Andrographolide Effectively Inhibit SARS-CoV-2 and Related Viruses In Vitro.

Since the first reported case caused by the novel coronavirus SARS-CoV-2 infection in Wuhan, COVID-19 has caused serious deaths and an ongoing global pandemic, and it is still raging in more than 200 countries and regions around the world and many new variants have appeared in the process of continuous transmission. In the early stage of the epidemic prevention and control and clinical treatment, traditional Chinese medicine played a huge role in China. Here, we screened out six monomer compounds, including artemether, artesunate, arteannuin B, echinatin, licochalcone B and andrographolide, with excellent anti-SARS-CoV-2 and anti-GX_P2V activity from Anti-COVID-19 Traditional Chinese Medicine Compound Library containing 389 monomer compounds extracted from traditional Chinese medicine prescriptions "three formulas and three drugs". Our discovery preliminary proved the stage of action of those compounds against SARS-CoV-2 and provided inspiration for further research and clinical applications.

Antidiabetic Effect of Artemether in Db/Db Mice Involves Regulation of AMPK and PI3K/Akt Pathways.

The traditional Chinese medicine has long been used in the treatment of diabetes, one major disease threatening the public health. It has been reported that artemether exerts antidiabetic effects on type 2 diabetes in db/db mice, however the underlying mechanisms remain unknown. In the present study, we show that artemether regulates expression of related enzymes participating in the glucose and lipid metabolism in the liver of db/db mice, which could at least partly explain the improved glucose and lipid metabolism in artemether-treated mice. Additionally, artemether also regulates expression of glycogen synthesis related enzymes in the skeletal muscle of db/db mice, supporting its promotive role in glycogen synthesis. Mechanistically, artemether activates AMPK pathway as well as PI3K/Akt pathway in the liver and skeletal muscle of db/db mice, suggesting that these two signaling pathways are both involved in the antidiabetic effects of artemether on type 2 diabetes in db/db mice. In conclusion, our study connects the antidiabetic effects of artemether to the regulation of metabolic enzymes and signaling pathways, and also provides molecular basis for the potential application of artemether in treating type 2 diabetes.

Vitamin C administration attenuated artemether induced hepatic injury in rats / La aAdministración de vitamina C atenúa la lesión hepática inducida por artemeter en ratas

This research was designed to investigate the potential protective effect of vitamin C supplementation against hepatocyte ultrastructural alterations induced by artemether (antimalarial drug) administration. Twenty-four adult male albino rats were used in this study and were divided into four groups (n=6). Group I served as a control and rats in group II administrated artemether (4 mg/kg B.W) orally for three consecutive days. Group III administered artemether plus a low dose of vitamin C (2.86 mg/kg/l water) while group IV received artemether plusa high dose of vitamin C (8.56 mg/kg). At the end of the experimental period (14 days), the harvested liver tissues were examined by transmission electron microscopy (TEM), and blood samples were assayed for biomarkers of liver injury and oxidative stress. Artemether significantly (p<0.05) augmented biomarkers of liver injury such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and oxidative stress such as superoxide dismutase (SOD), Glutathione Peroxidase (GPX), and caused degeneration and damage of the rough endoplasmic reticulum and disrupted mitochondria. The blood sinusoids were also damaged with distortion of their canaliculi. Administration of vitamin C showed improvement of liver biomarkers, and liver parenchyma, especially in a high dose of vitamin C.We concludes that vitamin C is a partial protective agent against artemether-induced liver injury.

Esta investigación fue diseñada para investigar el posible efecto protector de la vitamina C contra las alteraciones ultraestructurales de los hepatocitos, inducidas por la administración de arteméter (medicamento antipalúdico). En el estudio se utilizaron 24 ratas albinas macho adultas y se dividieron en cuatro grupos (n = 6). El grupo I fue designado como control y las ratas en el grupo II se adminstró Arteméter (4 mg / kg de peso corporal) por vía oral durante tres días consecutivos. En el grupo III se administró arteméter, además de una dosis baja de vitamina C (2,86 mg / kg / l de agua) mientras que el grupo IV recibió arteméter más una dosis alta de vitamina C (8,56 mg / kg). Al final del período experimental (14 días), los tejidos hepáticos recolectados se examinaron por microscopía electrónica de transmisión (MET), y las muestras de sangre se analizaron en busca de biomarcadores de daño hepático y estrés oxidativo. El arteméter aumentó significativamente (p <0,05) los biomarcadores de daño hepático como alanina aminotransferasa (ALT), aspartato aminotransferasa (AST) y estrés oxidativo como superóxido dismutasa (SOD), glutatión peroxidasa (GPX) y causó degeneración y daño de la retículo endoplásmico rugoso y mitocondrias alteradas. Los sinusoides sanguíneos también fueron dañados con la distorsión de sus canalículos. La administración de vitamina C mostró una mejoría de los biomarcadores hepáticos y el parénquima hepático, especialmente en una dosis alta de vitamina C. Concluimos que la vitamina C es un agente protector parcial contra la lesión hepática inducida por arteméter.

Effect of omega-3 fatty acids administered as monotherapy or combined with artemether on experimental Schistosoma mansoni infection.

Schistosomiasis is on the top list of endemic diseases in sub-Saharan Africa. Praziquantel is the drug of choice for treatment of human schistosomiasis. Yet, the sole dependence on the drug raises concerns about the potential for increased drug resistance, which would subsequently result in searching for alternative preventive chemotherapy options, ideally among natural compounds. Therefore, we conducted this work to assess the effect of omega-3 polyunsaturated fatty acids [(ω-3) PUFAs] monotherapy or combined therapy with artemether (ART) against Schistosoma mansoni infection in a mouse model. A total of 42 mice were divided into 4 groups and infected with 50 ± 5 S. mansoni cercariae for 10 weeks. Mice were treated orally with either (ω-3) PUFAs as 273 mg/ kg, 4 times/ week throughout the experiment, ART as a single dose of 400 mg/ kg, 3 weeks post-infection, or combined ART + (ω-3) PUFAs using the same respective treatment regimen, while infected untreated mice were served as controls. The study explored that combined administration of (ω-3) PUFAs and ART has the best schistosomicidal efficacy as it significantly reduced liver and spleen indices, worm count, egg burdens, and granulomas count as well as diameter. Besides, the combined regimen was associated with a significant decrease in both hepatic nitric oxide and serum interleukin-4 level. The results highlighted the possibility of using (ω-3) PUFA combined with ART as a novel anti-schistosomal combination therapy. However, further researches should be conducted to clarify the possible synergistic mechanism/s between the two natural compounds.

A novel cell-free method to culture Schistosoma mansoni from cercariae to juvenile worm stages for in vitro drug testing.

BACKGROUND: The arsenal in anthelminthic treatment against schistosomiasis is limited and relies almost exclusively on a single drug, praziquantel (PZQ). Thus, resistance to PZQ could constitute a major threat. Even though PZQ is potent in killing adult worms, its activity against earlier stages is limited. Current in vitro drug screening strategies depend on newly transformed schistosomula (NTS) for initial hit identification, thereby limiting sensitivity to new compounds predominantly active in later developmental stages. Therefore, the aim of this study was to establish a highly standardized, straightforward and reliable culture method to generate and maintain advanced larval stages in vitro. We present here how this method can be a valuable tool to test drug efficacy at each intermediate larval stage, reducing the reliance on animal use (3Rs). METHODOLOGY/PRINCIPAL FINDINGS: Cercariae were mechanically transformed into skin-stage (SkS) schistosomula and successfully cultured for up to four weeks with no loss in viability in a commercially available medium. Under these serum- and cell-free conditions, development halted at the lung-stage (LuS). However, the addition of human serum (HSe) propelled further development into liver stage (LiS) worms within eight weeks. Skin and lung stages, as well as LiS, were submitted to 96-well drug screening assays using known anti-schistosomal compounds such as PZQ, oxamniquine (OXM), mefloquine (MFQ) and artemether (ART). Our findings showed stage-dependent differences in larval susceptibility to these compounds. CONCLUSION: With this robust and highly standardized in vitro assay, important developmental stages of S. mansoni up to LiS worms can be generated and maintained over prolonged periods of time. The phenotype of LiS worms, when exposed to reference drugs, was comparable to most previously published works for ex vivo harvested adult worms. Therefore, this in vitro assay can help reduce reliance on animal experiments in search for new anti-schistosomal drugs.

Semisynthetic Derivative of Artemisia annua-Loaded Transdermal Bioadhesive for the Treatment of Uncomplicated Malaria Caused by Plasmodium falciparum in Children.

According to the most recent World Health Organization statistics, malaria infected approximately 219 million people in 2017, with an estimate of 435,000 deaths (World Health Organization, 2018). Communities isolated from cities are the most deprived of access to the necessary hospital facilities. Herein we report the development of a transdermal bioadhesive containing artemether (ART), an alternative, potentially lifesaving, treatment regimen for malaria in low-resource settings. Bioadhesives were prepared from an aqueous blend of hydroxyethylcellulose (4.5% w/w), ART, propoxylated-ethoxylated-cetyl-alcohol, polysorbate 80, propyleneglycol, glycerine, mineral oil, and oleic acid. In this study, the average pore size of bioadhesive 5.5b was 52.6 ± 15.31 µm. Differential scanning calorimetry and thermogravimetric analyses confirm the thermal stability of ART bioadhesives at room temperature. Tensile tests indicated good mechanical properties for bioadhesive 5.5b, when compared to 5.5a, where 5.5b showed elastic modulus 0.19 MPa, elongation at break 204%, tensile stress 0.31 MPa, tensile strength at break 0.23 MPa. Bioadhesion assays suggested that formulations containing surfactants had higher detachment forces. Permeation studies demonstrated that the best outcome was achieved with a bioadhesive containing 25 mg ART (5.5b) that after 24 h released 6971 ± 125 µg, which represents approximately 28% of drug permeation. Data reported presents a promising candidate for a new antimalarial transdermal formulation.

Paeoniflorin in experimental BALB/c mansoniasis: A novel anti-angiogenic therapy.

Chronic hepatic schistosomiasis causes portal hypertension, fibrosis and lethal hepatosplenic complications. Previous studies focused mainly on schistosomicidal drugs and neglected the therapeutic approaches against the vascular complications after portal hypertension. Investigating a novel anti-angiogenic therapy is an urgent. The current study is to evaluate the performance of Paeoniflorin (PAE) as an anti-angiogenic therapy, being a powerful anti-fibrotic, compared to artemether (ART) and praziqantel (PZQ) in schistosomiasis mansoni BALB/c mice. Thirty two laboratory bred male BALB/c Swiss albino mice. The mice were classified into four groups (8 mice each), control infected (CI), PZQ (300 mg/kg/12 h), ART (0.1 ml/mg/d) and PAE (50 mg/kg/d) treated groups for one month. All mice groups were sacrificed 15 weeks post infection for assessment of the drugs' efficacy by parasitological, histopathological and immunohistochemical studies. Our results in PAE group showed marked reduction in the mean egg count/gram stool, worm burden, egg count/gram liver tissue, granuloma diameter and pro-angiogenic factors as vascular endothelial growth factor (VEGF), Proliferating cell nuclear antigen (PCNA), alpha-smooth muscle actin (α-SMA) and CD34; conversely, there was an augmentation of the tissue inhibitor metalloproteinases-2 (TIMP-2) as an anti-angiogenic expression that was exceeded ART and PZQ treated groups compared to CI group (p˂0.001). Conclusively, PAE has an anti-angiogenic impact with no vascular proliferative activity or recanalization, no micro-vessel density (MVD) changes, granuloma resolution and fibrosis regression. PAE is predicted to be a potential therapy for chronic hepatic diseases associated with fibrosis and angiogenesis, hopeful in protecting from advanced serious complications; cancer and metastasis.

The activity of Artemisia spp. and their constituents against Trypanosomiasis.

BACKGROUND: Trypanosomiasis belongs to the neglected tropical diseases. Although standard therapies are available, the safety and efficacy of current synthetic drugs are limited due to the development of drug resistance and adverse side effects. PURPOSE: Artemisia annua and artemisinin are not only active against Plasmodia, but also other protozoa. Therefore, we reviewed the literature on species of the genus Artemisia and their phytochemicals regarding their activity against trypanosomes. STUDY DESIGN: A PubMed search for "Artemisia/Artemisinin and Trypanosoma" has been conducted for literature until December 2017. RESULTS: Interestingly, not only A. annua L. and its active principle, artemisinin revealed inhibitory activity towards trypanosomes. Other Artemisia species (A. absinthium, A. abyssinica, A. afra, A. douglasia, A. elegantissima, A. maciverae, A. mexicana, and A. roxburghiana) also inhibited T. brucei, T. cruzi, or T. congolense. The plants contained numerous chemical constituents including 3',4'-dihydroxybonanzin, apigenin, betulinic acid, bonanzin, dehydroleucodine, dihydroluteolin, dracunculin and bis-dracunculin, helenalin, nepetin, scoparol, scopoletin, stigmasterol, (Z)-p­hydroxy cinnamic acid, ß-sitosterol and others. In addition to artemisinin from A. annua, artemether and artesunate, further novel artemisinin derivatives and nanotechnological preparations may also be useful to combat Trypanosoma infections. CONCLUSION: There are numerous results reporting on the anti-trypanosomal activity the genus Artemisia, artemisinin and its derivatives and other phytochemicals from Artemisia species. This field of research is, however, still in its infancy and more intensive research is required to explore the full potential of diverse Artemisia species and their chemical ingredients for eradication of trypanosomal infections.

Determination of the structures of radicals formed in the reaction of antimalarial drug artemisinin with ferrous ions.

While artemisinin 1 has been widely used to treat malaria in traditional Chinese medicine, its exact antimalarial mechanism remains unclear. To elucidate the mechanisms of the antimalarial action by artemisinin, the reactions of artemisinin, artemether 2 and artesunate 3 with Fe2+ were analyzed using an electron spin resonance (ESR), high performance liquid chromatography-electron spin resonance (HPLC-ESR) and high performance liquid chromatography-electron spin resonance-mass spectrometer (HPLC-ESR-MS). α-(4-Pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) was used as a spin trap reagent in the reactions. Radicals were detected by ESR and structures of the radicals were determined by HPLC-ESR-MS. Based on the ions, m/z 478, m/z 418 and m/z 238 which were determined by HPLC-ESR-MS, we identified following radicals: artemisinin-derived primary and secondary radicals, 6 and 7; acetyl radical, 8; a radical formed through elimination of acetyl group from 6, 10 in the reaction of artemisinin with Fe2+. Radicals, 7 and 8 were also detected in the reaction of artemether and artesunate.

In vitro effects of co-incubation of blood with artemether/lumefantrine & vitamin C on the viscosity & elasticity of blood.

BACKGROUND & OBJECTIVES: The antimalarial combination drug artemether/lumefantrine has been shown to be effective against malaria parasite through its haemolytic action. This drug is sometimes co-administered with vitamin C in patients with malaria. Vitamin C is associated with antioxidant properties which would be expected to protect against haemolytic effects of this antimalarial drug. This study was designed to investigate in vitro effects of co-incubation of artemether/lumefantrine with vitamin C on the viscosity and elasticity of blood. METHODS: Blood was collected from 12 healthy female volunteers with normal haemoglobin genotype (HbAA). A Bioprofiler was used to measure the viscosity and elasticity of untreated blood samples (control) and samples exposed to artemether/lumefantrine (0.06/0.36 mg/ml) alone and with low or high dose vitamin C (equivalent to adult doses of 100 or 500 mg). RESULTS: artemether/lumefantrine significantly (p<0.05) reduced viscosity of blood from 4.72 ± 0.38 to 3.78 ± 0.17 mPa.s. Addition of vitamin C (500 mg) further reduced blood viscosity to 2.67 ± 0.05 mPa.s. The elasticity of blood was significantly (p<0.05) reduced from 0.33 ± 0.04 mPa.s to 0.24 ± 0.03 mPa.s by the antimalarial drug, and further reduced to 0.13 ± 0.02 mPa.s in the presence of vitamin C (500 mg). INTERPRETATION & CONCLUSIONS: Co-incubation of blood with vitamin C and antimalarial combination drug potentiates the haemolytic effects of the latter on reducing blood viscosity and elasticity in vitro. This may possibly have implications in relation to haemolysis in patients receiving vitamin C supplementation with artemether/lumefantrine during malaria therapy.