Efficacy of artemether and artesunate in mice infected with praziquantel non-susceptible isolate of Schistosoma japonicum

Efficacy of artemether against toxocariasis in mice: parasitological and immunopathological changes in brain, liver, and lung

Toxocariasis is a zoonosis that represents a serious threat to public health particularly in tropical and subtropical areas. Currently, albendazole, the most effective drug for treating visceral toxocariasis, shows moderate efficacy against the larvae in tissues and has some adverse effects. Artemether is an antiparasitic drug mainly used in the treatment of malaria and showed effectiveness against numerous helminthic infections. Besides, it possesses potent anti-inflammatory, antiapoptotic, antifibrotic, and neuroprotective properties. Thus, the study's aim was to investigate artemether's effects in comparison with albendazole on the therapeutic outcome of experimental toxocariasis. For this aim, 140 laboratory-bred mice were divided into four main groups: uninfected control, treatment control, albendazole-treated, and artemether-treated groups. The treatment regimens were started at the 15th dpi (early treatment), and at the 35th dpi (late treatment). The effectiveness of treatment was determined by brain larval count, histopathological, immunohistochemical, and biochemical examination. Artemether showed more effectiveness than albendazole in reducing brain larval counts, markers of brain injury including NF-κB, GFAP, and caspase-3, the diameter and number of hepatic granulomas, hepatic oxidative stress, hepatic IL-6, and TG2 mRNA, and pulmonary inflammation and fibrosis. The efficacy of artemether was the same when administered early or late in the infection. Finally, our findings illustrated that artemether might be a promising therapy for T. canis infection and it could be a good substitution for albendazole in toxocariasis treatment.

Recent pharmacological advances in the repurposing of artemisinin drugs

Artemisinins are a family of sesquiterpene lactones originally derived from the sweet wormwood (Artemisia annua). Beyond their well-characterized role as frontline antimalarial drugs, artemisinins have also received increased attention for other potential pharmaceutical effects, which include antiviral, antiparsitic, antifungal, anti-inflammatory, and anticancer activities. With concerted efforts in further preclinical and clinical studies, artemisinin-based drugs have the potential to be viable treatments for a great variety of human diseases. Here, we provide a comprehensive update on recent reports of pharmacological actions and applications of artemisinins outside of their better-known antimalarial role and highlight their potential therapeutic viability for various diseases.

Application of Dendrimers for Treating Parasitic Diseases

Despite advances in medical knowledge, parasitic diseases remain a significant global health burden and their pharmacological treatment is often hampered by drug toxicity. Therefore, drug delivery systems may provide useful advantages when used in combination with conventional therapeutic compounds. Dendrimers are three-dimensional polymeric structures, characterized by a central core, branches and terminal functional groups. These nanostructures are known for their defined structure, great water solubility, biocompatibility and high encapsulation ability against a wide range of molecules. Furthermore, the high ratio between terminal groups and molecular volume render them a hopeful vector for drug delivery. These nanostructures offer several advantages compared to conventional drugs for the treatment of parasitic infection. Dendrimers deliver drugs to target sites with reduced dosage, solving side effects that occur with accepted marketed drugs. In recent years, extensive progress has been made towards the use of dendrimers for therapeutic, prophylactic and diagnostic purposes for the management of parasitic infections. The present review highlights the potential of several dendrimers in the management of parasitic diseases.

Research Progress on Artemisinin and Its Derivatives against Hematological Malignancies

Although current therapeutic methods against hematological malignancies are effective in the early stage, they usually lose their effectiveness because of the development of drug resistances. Seeking new drugs with significant therapeutic effects is one of the current research hotspots. Artemisinin, an extract from the plant Artemisia annua Linne, and its derivatives have excellent antimalarial effects in clinical applications as well as excellent safety. Recent studies have documented that artemisinin and its derivatives (ARTs) also have significant effects against multiple types of tumours, including hematological malignancies. This review focuses on the latest research achievements of ARTs in the treatment of hematological malignancies as well as its mechanisms and future applications. The mechanisms of ARTs against different types of hematological malignancies mainly include cell cycle arrest, induction autophagy and apoptosis, inhibition of angiogenesis, production of reactive oxygen species, and induction of differentiation. Additionally, the review also summarizes the anticancer effects of ARTs in many drug-resistant hematological malignancies and its synergistic effects with other drugs.

Enantioselective Plasma Pharmacokinetic Study of a Novel Anti- Sichistosomiasis Agent P96 in Rat by Liquid Chromatography-tandem Mass Spectrometry

Background:

2-Cyclopentanecarbonyl-1,2,3,6,7,11b-hexahydro-pyrazino[2,1- a]isoquinolin- 4-one (P96), was found to be a novel drug candidate with one chiral center to treat schistosomiasis caused by Schistosoma japonicum. </P><P> Objective: To study pharmacokinetic characteristics, a simple, rapid and sensitive liquid chromatography- tandem mass spectrometry (LC-MS/MS) method was developed and fully validated for the quantification analysis of P96 in rat plasma.

Methods:

Chromatographic separation was performed on a C18 column with gradient eluted mobile phase composed of acetonitrile and water at a flow rate of 0.5 mL/min. Detection was performed on a triple-quadrupole tandem mass spectrometer using positive mode electrospray ionization in the multiple reactions monitoring (MRM) mode.

Results:

Excellent linearity was observed in the range of 3-900 ng/mL with the lower limit of quantification of 3 ng/mL in rat plasma for P96. The intra- and inter-day precisions exhibited less than 6.6%. Mean recoveries ranged from 96.9% to 102.4%. This method was applied to investigate the enantioselective differences on the pharmacokinetics between (R,S)-P96 and its enantiomers in rats after oral administration. The enantioselective differences of (R)-P96, (S)-P96 and (R,S)-P96 were found and compared.

Conclusion:

The established method was found to be accurate, precise, and sensitive and can be applied to investigate the stereoselective differences on pharmacokinetics between rac-P96 and its enantiomers.

Use of artesunate in non-malarial indications

INTRODUCTION

Artesunate and other artemisinin derivatives are used in various infectious and non-infectious diseases. We aimed to analyze available data on artesunate and artemisinin derivatives activity in humans and their potential clinical benefits in non-malarial indications.

MATERIAL AND METHODS

Literature review performed on PubMed and the Cochrane Library databases using the PRISMA method. We analyzed studies published in English from January 2008 to August 2017 using the same indicators of drug efficacy.

RESULTS

We included 19 studies performed in humans (1 meta-analysis, 1 literature review, 4 randomized controlled trials, 3 prospective controlled trials, 3 prospective uncontrolled trials, 2 exploratory phase 1 or 2 trials, 1 case series, and 4 case reports). Artesunate and artemisinin derivatives demonstrated efficacy in the treatment of schistosomiasis in combination with praziquantel (P=0.003). Artesunate monotherapy was less effective than praziquantel alone (P<0.001) probably because its activity only affects the early stages of Schistosoma parasites. Artesunate monotherapy could be interesting as a chemoprophylactic drug against schistosomiasis (P<0.001). Findings seem promising but are still controversial in the treatment of multidrug-resistant CMV infections. Studies do not conclude on artesunate and artemisinin derivatives efficacy in the treatment of cervix, breast, colorectal, and lung cancers.

CONCLUSION

Artesunate and artemisinin derivatives in combination with praziquantel were effective against schistosomiasis, and could be used as a chemoprophylactic drug alone. They could be interesting as anti-CMV and anti-tumor treatment. Additional trials in humans are required to assess the efficacy of artesunate and artemisinin derivatives in diseases other than malaria.

Implication of artemisinin nematocidal activity on experimental trichinellosis: In vitro and in vivo studies

Benzimidazole drugs are used for treatment of trichinellosis, but they have a limited effect against encapsulated larval stages of Trichinella spiralis. Hence, there is a considerable interest in developing new anthelmintic drugs. Our aim is to investigate the possible effect of artemisinin on T. spiralis in in vitro and in vivo studies. T. spiralis worms were isolated from infected mice and transferred to 3 culture media; group I: with no drugs, group II: contained artemisinin and group III: contained mebendazole, then they were subjected to electron microscopic study. An in vivo study was done where mice were divided into three groups; group I: infected and untreated, group II: received artemisinin and group III: received mebendazole. The efficacy of treatment was assessed by adult and total larval counts, histopathological study of the small intestinal and muscle tissues and immunohistochemical staining of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in muscles. Adult worm teguments showed significant degeneration and destruction with both drugs. Also, significant reduction of total adult and larval counts occurred in treated groups in comparison to the control group. Histopathological examination of the small intestine and muscles showed marked improvement with reduction in the inflammatory infiltrates with both drugs. COX-2 and VEGF expressions were reduced in both treated groups with more reduction in the artemisinin-treated group. This study revealed that artemisinin has the potential to be an alternative drug against trichinellosis.

Efficacy and Safety of Moxidectin, Synriam, Synriam-Praziquantel versus Praziquantel against Schistosoma haematobium and S. mansoni Infections: A Randomized, Exploratory Phase 2 Trial

Background

Schistosomiasis affects millions of people, yet treatment options are limited. The antimalarial Synriam (piperaquine 150 mg/arterolane 750 mg) and the anthelminthic moxidectin revealed promising antischistosomal properties in preclinical or clinical studies.

Methodology

We conducted two single-blind, randomized exploratory Phase 2 trials in Schistosoma mansoni and S. haematobium-infected adolescents in northern and central Côte d’Ivoire. Our primary endpoints were cure rates (CRs) and egg reduction rates (ERRs) based on geometric mean and safety. Each subject was asked to provide two stool samples (S. mansoni trial) for Kato-Katz analysis or three urine samples (S. haematobium trial) for urine filtration and one finger prick for malaria screening at baseline and follow-up. Participants were randomly assigned to either moxidectin, Synriam, Synriam plus praziquantel or praziquantel.

Principal Findings

128 adolescents (age: 12–17 years) were included in each study. Against S. haematobium moxidectin and Synriam revealed low efficacy. On the other hand, Synriam plus praziquantel and praziquantel yielded CRs of 60.0% and 38.5% and ERRs of 96.0% and 93.5%, respectively. CRs observed in the treatment of S. mansoni were 13.0%, 6.7%, 27.0%, and 27.6% for moxidectin, Synriam, Synriam plus praziquantel and praziquantel, respectively. ERRs ranged from 64.9% (Synriam) to 87.5% (praziquantel).

Conclusion/Significance

Synriam and moxidectin show low efficacy against S. haematobium, hence an ancillary benefit is not expected when these drugs are used for treating onchocerciasis and malaria in co-endemic settings. Further studies are needed to corroborate our findings that moxidectin and Synriam show moderate ERRs against S. mansoni.

Schistosomiasis is a parasitic infection that affects millions of people all over the world and it is due to schistosomes, helminths (worms) that infect the intestine and the urinary bladder. Treatment options are limited, with praziquantel being the only used drug. The antimalarial Synriam and the anthelminthic moxidectin revealed good action against this worm in previous studies. We conducted two studies in Schistosoma mansoni and S. haematobium-infected adolescents in Côte d’Ivoire. Subjects positive for the infection were allocated by chance to the four groups of treatment (moxidectin, Synriam, Synriam plus praziquantel or praziquantel); participants did not know which drug they took. Our aim was to calculate how many participants were negative after the treatment and how did the intensity of infection change before and after treatment. Each subject provided stools and urines for examination. 128 adolescents were included in each study. Moxidectin and Synriam did not work well against S. haematobium. Against S. mansoni, only a small part of the participants were negative after treatment in all treatment groups, but the intensity of infections were reduced. Further studies are needed to better understand this result.

Natural products as leads in schistosome drug discovery

Schistosomiasis is a neglected parasitic tropical disease that claims around 200,000 human lives every year. Praziquantel (PZQ), the only drug recommended by the World Health Organization for the treatment and control of human schistosomiasis, is now facing the threat of drug resistance, indicating the urgent need for new effective compounds to treat this disease. Therefore, globally, there is renewed interest in natural products (NPs) as a starting point for drug discovery and development for schistosomiasis. Recent advances in genomics, proteomics, bioinformatics, and cheminformatics have brought about unprecedented opportunities for the rapid and more cost-effective discovery of new bioactive compounds against neglected tropical diseases. This review highlights the main contributions that NP drug discovery and development have made in the treatment of schistosomiasis and it discusses how integration with virtual screening (VS) strategies may contribute to accelerating the development of new schistosomidal leads, especially through the identification of unexplored, biologically active chemical scaffolds and structural optimization of NPs with previously established activity.

New uses for old drugs: the tale of artemisinin derivatives in the elimination of schistosomiasis japonica in China

Artemisinin (qinghaosu), extracted from the Chinese herb Artemisia annua L. in 1972, and its three major derivatives--artemether, artesunate and dihydroartemisinin--were firstly identified as antimalarials and found active against all species of the malaria parasite. Since the early 1980s, artemisinin and its derivatives have been found efficacious against Schistosoma spp., notably larval parasites, and artemisinin derivatives have played a critical role in the prevention and treatment of human schistosomiasis in China. Currently, China is moving towards the progress of schistosomiasis elimination. However, the potential development of praziquantel resistance may pose a great threat to the progress of elimination of schistosomiasis japonica in China. Fortunately, these three major artemisinin derivatives also exhibit actions against adult parasites, and reduced sensitivity to artemether, artesunate and dihydroartemisinin has been detected in praziquantel-resistant S. japonicum. In this review, we describe the application of artemisinin derivatives in the prevention and treatment of schistosomiasis japonica in China, so as to provide tools for the global agenda of schistosomiasis elimination. In addition to antimalarial and antischistosomal actions, they also show activities against other parasites and multiple cancers. Artemisinin derivatives, as old drugs identified firstly as antimalarials, continue to create new stories.