The sensitivity of artesunate against Schistosoma japonicum decreased after 10 years of use in China

New clinical application prospects of artemisinin and its derivatives: a scoping review

BACKGROUND

Recent research has suggested that artemisinin and its derivatives may have therapeutic effects on parasites, viruses, tumors, inflammation and skin diseases. This study aimed to review clinical research on artemisinin and its derivatives except anti-malaria and explore possible priority areas for future development.

METHODS

Relevant articles in English and Chinese published before 28 October 2021 were reviewed. All articles were retrieved and obtained from databases including WanFang, PubMed/MEDLINE, the Cochrane Library, China National Knowledge International, Embase, OpenGrey, the Grey Literature Report, Grey Horizon, and ClinicalTrials.gov. Studies were selected for final inclusion based on predefined criteria. Information was then extracted and analyzed by region, disease, outcome, and time to identify relevant knowledge gaps.

RESULTS

Seventy-seven studies on anti-parasitic (35), anti-tumor (16), anti-inflammatory (12), anti-viral (8), and dermatological treatments (7) focused on the safety and efficacy of artemisinin and its derivatives. The anti-parasitic clinical research developed rapidly, with a large number of trials, rapid clinical progress, and multiple research topics. In contrast, anti-viral research was limited and mainly stayed in phase I clinical trials (37.50%). Most of the studies were conducted in Asia (60%), followed by Africa (27%), Europe (8%), and the Americas (5%). Anti-parasite and anti-inflammatory research were mainly distributed in less developed continents such as Asia and Africa, while cutting-edge research such as anti-tumor has attracted more attention in Europe and the United States. At the safety level, 58 articles mentioned the adverse reactions of artemisinin and its derivatives, with only one study showing a Grade 3 adverse event, while the other studies did not show any related adverse reactions or required discontinuation. Most studies have discovered therapeutic effects of artemisinin or its derivatives on anti-parasitic (27), anti-tumor (9), anti-inflammatory (9) and dermatological treatment (6). However, the efficacy of artemisinin-based combination therapies (ACTs) for parasitic diseases (non-malaria) is still controversial.

CONCLUSIONS

Recent clinical studies suggest that artemisinin and its derivatives may be safe and effective candidates for anti-tumor, anti-parasitic, anti-inflammatory and dermatological drugs. More phase II/III clinical trials of artemisinin and its derivatives on antiviral effects are needed.

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.

Genome-wide miRNAs expression profiles of Schistosoma japonicum schistosomula in response to artesunate

Aim: miRNAs play a significant role in pharmacogenomics and are likely to be important in the molecular mechanism of atesunate (ART) effects on Schistosoma japonicum. Methods: We sequenced the RNAs using an Illumina (Solexa) DNA sequencer and compared the relative expression levels of the miRNAs in 10-day-old schistosomula from ART and the parallel control group. Results: We characterized 95 known miRNAs from S. japonicum schistosomula individuals, including 38 novel miRNA families. Among the detectable 134 miRNAs differentially expressed (>2.0-fold change, p < 0.01) after ART treatment in schistosomula, a total of seven known or novel 3p- or 5p- derived S. japonicum miRNAs were characterized. We propose that sja-miR-125b may regulate the expression of ART metabolizing enzymes, glutathione synthetase or heme-binding protein 2 to help S. japonicum resists or adapts to drug stress and also ART may significantly inhibit sexual maturation of female worms mediated by mir-71b/2 miRNA cluster. Conclusion: This was the first comprehensive miRNAs expression profile analysis of S. japonicum in response to ART, and provides an overview of the complex network of the mechanism of action of ART on S. japonicum.

Quantitative proteomic analyses of Schistosoma japonicum in response to artesunate

Artesunate (ART) has high prophylactic efficacy against Schistosoma japonicum infections and has been used to treat and prevent schistosomiasis in China since 1995. However, the molecular mechanism of ART's effects on S. japonicum remains unclear. Herein, we applied isobaric tagging reagents for relative and absolute quantification analyses coupled with two-dimensional liquid chromatography and tandem mass spectrometry to investigate the effect of ART on the proteome of S. japonicum in susceptible mice. 4529 proteins were quantified on the basis of 21,825 unique peptides. Comparative proteomic analyses revealed that 145, 228 and 185 proteins were significantly differentially expressed after ART treatment in schistosomula, juvenile and adult worms, respectively. Ninety proteins were differentially expressed between each two treatment groups in response to ART treatment: 67 proteins were associated with S. japonicum development/aging and 23 were specifically associated with ART treatment. Quantitative real-time PCR of selected genes verified the proteomic data. Gene ontology annotation and Kyoto encyclopedia of genes and genomes pathway mapping analysis showed that the majority of differentially expressed proteins were involved in stress/defense/detoxification, signal transduction, carbohydrate metabolism, amino acid metabolism, transcription/translation, and protein synthesis/assembly/degradation. Thirty-four of the proteins differentially expressed under ART treatment encoded hypothetical, uncharacterized proteins with unknown functions. This study obtained the first comprehensive protein expression profile of S. japonicum in response to ART, and provides a basis for a better understanding of the molecular mechanisms of ART effects on S. japonicum.

Meta-analysis of the diagnostic efficiency of the questionnaires screening for schistosomiasis

Schistosomiasis is the second widespread tropical disease that affects the health of over 240 million people of 78 countries. Questionnaires have been commonly used to diagnose schistosomiasis, while no meta-analysis of their efficacy had been reported previously. This meta-analysis was conducted to assess their diagnostic accuracy of schistosomiasis. Studies published prior to December 1, 2014, that had used questionnaires as a diagnostic tool were searched in PubMed, Medline, EMBASE, and China National Knowledge Infrastructure (CNKI) database. A total of 32 studies with 72,812 cases were identified for the meta-analysis. The best diagnostic odds ratio (DOR) was obtained from Schistosoma haematobium (67.68, 95 % confidence interval (CI) = 31.48 to 145.54), followed by Schistosoma japonicum (11.74, 95 % CI = 4.59 to 30.05) then Schistosoma mansoni (2.98, 95 % CI = 1.95 to 4.54). Pooled sensitivity and specificity were respectively 0.82, 0.88, and 0.46, and 0.59, 0.86, and 0.81 for S. japonicum, S. haematobium, and S. mansoni. The multivariable subgroup analyses showed that the questionnaires which had been pretested and standardized had better diagnostic performance. The result suggested that questionnaires can be used to diagnose schistosomiasis with moderate sensitivity and specificity and the questionnaires for diagnosing S. haematobium performed best.

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.

Schistosomiasis chemotherapy

After malaria, schistosomiasis (or bilharzia) is the second most prevalent disease in Africa, and is occurring in over 70 countries in tropical and subtropical regions. It is estimated that 600 million people are at risk of infection, 200 million people are infected, and at least 200,000 deaths per year are associated with the disease. All schistosome species are transmitted through contact with fresh water that is infested with free-swimming forms of the parasite, which is known as cercariae and produced by snails. When located in the blood vessels of the host, larval and adult schistosomes digest red cells to acquire amino acids for growth and development. Vaccine candidates have been unsuccessful up to now. Against such devastating parasitic disease, the antischistosomal arsenal is currently limited to a single drug, praziquantel, which has been used for more than 35 years. Because the question of the reduction of the activity of praziquantel was raised recently, it is thus urgent to create new and safe antischistosomal drugs that should be combined with praziquantel to develop efficient bitherapies.

Efficacy of praziquantel and artemisinin derivatives for the treatment and prevention of human schistosomiasis: a systematic review and meta-analysis

Background

Praziquantel has been used as first-line drug for chemotherapy of schistosomiasis since 1984. Besides praziquantel, artemether and artesunate have also been used for the control of this infectious disease since late 1990s. In this article, we conducted a systematic review and meta-analysis to evaluate the antischistosomal efficacy of different medication strategies including monotherapy or combination therapies of these drugs.

Results

A number of 52 trials from 38 articles published in peer-reviewed journals before July 2011 were selected for analysis after searching the following literature databases: the Cochrane Library, PubMed/Medline, ISI Web of Science, Chinese Biomedicine Literature Database, and China National Knowledge Infrastructure. Our meta-analyses showed that a dosage of 30-60 mg/kg praziquantel compared with placebo produced a protection rate of about 76% (95% CI: 67%-83%) for treating human schistosomiasis, which varied from 70% to 76% with no significant differences among the subspecies S. haematobium, S. japonicum or S. mansoni. Protection rates were higher when praziquantel doses were elevated, as concluded from the nRCTs results: the protection rate of praziquantel at 40 mg/kg was 52% (95% CI: 49%-55%), and it increased to 91% (95% CI: 88%-92%) when the dosages were elevated to 60/80/100 mg/kg divided two or more doses. Multiple doses of artemether or artesunate over 1- or 2-week intervals resulted in protection rates of 65% to 97% for preventing schistosomiasis, and increased doses and shorter medication intervals improved their efficacies. Praziquantel and artemisinin derivatives (artemether or artesunate) in combination resulted in a higher protection rate of 84% (95% CI: 64%-91%) than praziquantel monotherapy for treatment. praziquantel and artesunate in combination had a great protection rate of 96% (95% CI: 78%-99%) for preventing schistosomes infection.

Conclusions

According to the results, praziquantel remains effective in schistosomiasis treatment, and multiple doses would improve its efficacy; meanwhile, praziquantel is also a good drug for preventing acute schistosomiasis morbidity. It's better to use multiple doses of artemether or artesunate with 1- or 2-week intervals for prevention against schistosome infection. Praziquantel and artemether or artesunate in combination perform better in treatment than praziquantel monotherapy, and they are especially suitable for treating the patients with repeated exposure to infected water.