Evaluation of prophylactic efficacy and safety of praziquantel-miltefosine nanocombination in experimental Schistosomiasis mansoni

Current drug strategies for the treatment and control of schistosomiasis

INTRODUCTION

Schistosomiasis, one of the current Neglected Tropical Diseases (NTDs) affects over 230 million people globally, with nearly 700 million at risk in more than 74 countries. Praziquantel (PZQ) has served as the primary treatment for the past four decades; however, its effectiveness is limited as it solely eliminates adult worms. In regions where infections are frequent, PZQ exhibits only temporary efficacy and has restricted potential to disrupt the prolonged transmission of the disease.

AREAS COVERED

A comprehensive exploration using the PubMed database was conducted to review current pharmacotherapy approaches for schistosomiasis. This review also encompasses recent research findings related to potential novel therapeutics and the repurposing of existing drugs.

EXPERT OPINION

Current schistosoma treatment strategies, primarily relying on PZQ, face challenges like temporary effectiveness and limited impact on disease transmission. Drug repurposing, due to economic constraints, is decisive for NTDs. Despite PZQ's efficacy, its failure to prevent reinfection highlights the need for complementary strategies, especially in regions with persistent environmental foci. Integrating therapies against diverse schistosome stages boosts efficacy and impedes resistance. Uncovering novel agents is essential to address resistance concerns in tackling this neglected tropical disease. Integrated strategies present a comprehensive approach to navigate the complex challenges.

Appraisal of Chitosan-Coated Lipid Nano-Combination with Miltefosine and Albendazole in the Treatment of Murine Trichinellosis: Experimental Study with Evaluation of Immunological and Immunohistochemical Parameters

PURPOSE

Resistance and adverse consequences of albendazole (ABZ) in treating trichinellosis urged demand for secure and effective new drugs. The current study aimed to assess the effect of chitosan-coated lipid nano-combination with albendazole and miltefosine (MFS) in treating experimental murine trichinellosis and evaluating pathological and immunological changes of trichinellosis.

MATERIALS AND METHODS

One hundred twenty Swiss albino mice were divided into six groups. Each group was subdivided into a and b subgroups based on the scarification time, which was 7- and 40-days post-infection (PI), respectively. The treatment efficacy was evaluated using parasitological, histopathological, serological (interleukin (IL)-12 and IL-4 serum levels), immunohistochemical (GATA3, glutathione peroxidase1 (GPX1) and caspase-3), and scanning electron microscopy (SEM) methods.

RESULTS

The most effective drug was nanostructured lipid carriers (NLCs) loaded with ABZ (G5), which showed the most significant reduction in adults and larval count (100% and 92.39%, respectively). The greatest amelioration in histopathological changes was reported in G4 treated with MFS. GATA3 and caspase-3 were significantly reduced in all treated groups. GPX1 was significantly increased in G6 treated with MFS + NLCs. The highest degenerative effects on adults and larvae by SEM were documented in G6.

CONCLUSION

Loading ABZ or MFS on chitosan-coated NLCs enhanced their efficacy against trichinellosis. Although ABZ was better than MFS, their combination should be considered as MFS caused a significant reduction in the intensity of infection. Furthermore, MFS showed anti-inflammatory (↓GATA3) and antiapoptotic effects (↓caspase-3), especially in the muscular phase. Also, when loaded with NLCS, it showed an antioxidant effect (↑GPX1).

Resveratrol protects against Schistosoma mansoni-induced liver fibrosis by targeting the Sirt-1/NF-κB axis

Hepatic schistosomiasis is a prevalent form of chronic liver disease that drastically affects human health. Nevertheless, an antifibrotic drug that could suppress the development of hepatic fibrosis does not exist yet. The current study aimed to evaluate the effect of resveratrol, a natural polyphenol with multiple biological activities, on Schistosoma mansoni (S. mansoni)-induced hepatic fibrosis and delineate the underlying molecular mechanism. Swiss male albino mice were randomly assigned into infected and non-infected groups. Hepatic schistosomiasis infection was induced via exposure to S. mansoni cercariae. 6 weeks later, resveratrol was administrated either as 20 mg/kg/day or 100 mg/kg/day for 4 weeks to two infected groups. Another group received vehicle and served as infected control group. At the end of the study, portal hemodynamic, biochemical, and histopathological evaluation of liver tissues were conducted. Remarkably, resveratrol significantly reduced portal pressure, portal and mesenteric flow in a dose-dependent manner. It improved several key features of hepatic injury as evidenced biochemically by a significant reduction of bilirubin and liver enzymes, and histologically by amelioration of the granulomatous and inflammatory reactions. In line, resveratrol reduced the expression of pro-inflammatory markers; TNF-α, IL-1β and MCP-1 mRNA, together with fibrotic markers; collagen-1, TGF-β1 and α-SMA. Moreover, resveratrol restored SIRT1/NF-κB balance in hepatic tissues which is the main switch-off control for all the fibrotic and inflammatory mechanisms. Taken together, it can be inferred that resveratrol possesses a possible anti-fibrotic effect that can halt the progression of hepatic schistosomiasis via targeting SIRT1/ NF-κB signaling.

The potential curative and hepatoprotective effects of platelet rich plasma on liver fibrosis in Schistosoma mansoni experimentally infected mice

Trapped Schistosoma mansoni eggs trigger fibrotic liver disease that can continue to liver cirrhosis and failure. This work evaluates the outcome of platelet rich plasma (PRP) on S. mansoni-induced liver fibrosis by intraperitoneal (IP) and intrahepatic (IH) routes with/without Praziquantel (PZQ) treatment. Swiss albino mice (n = 162) were divided into non-infected (n = 66) and infected (n = 96) groups, then subdivided into non-treated and treated subgroups with PRP(IP), PRP(IH) 6th and 10th weeks post-infection, PZQ, PZQ + PRP(IP) and PZQ + PRP(IH) 6th and 10th weeks post-infection. Effects of treatments were evaluated by parasitological, histopathological and Immunohistochemical assessments. In the early assessment (12th week post-infection) of infected-treated groups, the mean granuloma number showed significant reduction in groups treated with PZQ + PRP (IH) 10th week, PRP (IP), PZQ + PRP (IP) and PZQ + PRP (IH) 6th week (33.33%, 33%, 27.77% and 27.22%, respectively). Furthermore, the mean granuloma diameter showed significant reduction in groups treated with PRP (IH) 10th week and PZQ + PRP (IP) (24.17% and 15.5%, respectively). Also, the fibrotic index showed significant reduction in groups treated with PZQ + PRP (IP), PRP (IP) and PZQ + PRP (IH) 6th week (48.18%, 46.81% and 41.36%, respectively). Transforming growth factor β1(TGF-β1) expression was in correlation with parasitological and histopathological results. Diminished TGF-β1 expression was mostly in infected groups treated with PZQ + PRP (IP), PZQ + PRP (IH) 6th week and PRP (IP) (88.63%, 88.63% and 77.27%, respectively). In the late assessment (14th week post-infection) of infected treated groups, TGF-β1expression was reduced in groups treated with PZQ, PRP (IH) 10th weeks, PRP (IP) (83.33%, 66.66%, 33.33% respectively). PRP showed promising anti-fibrotic effects on S. mansoni-induced liver fibrosis.

Computational Insights into Natural Antischistosomal Metabolites as SmHDAC8 Inhibitors: Molecular Docking, ADMET Profiling, and Molecular Dynamics Simulation

Schistosomiasis is a neglected tropical disease with a significant socioeconomic impact. It is caused by several species of blood trematodes from the genus Schistosoma, with S. mansoni being the most prevalent. Praziquantel (PZQ) is the only drug available for treatment, but it is vulnerable to drug resistance and ineffective in the juvenile stage. Therefore, identifying new treatments is crucial. SmHDAC8 is a promising therapeutic target, and a new allosteric site was discovered, providing the opportunity for the identification of a new class of inhibitors. In this study, molecular docking was used to screen 13,257 phytochemicals from 80 Saudi medicinal plants for inhibitory activity on the SmHDAC8 allosteric site. Nine compounds with better docking scores than the reference were identified, and four of them (LTS0233470, LTS0020703, LTS0033093, and LTS0028823) exhibited promising results in ADMET analysis and molecular dynamics simulation. These compounds should be further explored experimentally as potential allosteric inhibitors of SmHDAC8.

Praziquantel promotes protection against Schistosoma japonicum infection in mice

Praziquantel (PZQ) is the first line drug for the treatment of schistosomiasis. Several studies have confirmed that PZQ regulates host immunity, and we have recently found that pretreatment with PZQ enhances resistance against Schistosoma japonicum infection in buffaloes. We speculate that PZQ induces physiological changes in mice that prevent S. japonicum infection. To test this hypothesis and provide a practical measure to prevent S. japonicum infection, we determined the effective dose (the minimum dose), protection period and onset time of protection by comparing the worm burden, female worm burden and egg burden in PZQ-pretreated mice and blank control mice. Morphological differences between parasites were observed by measuring the total worm length, oral sucker, ventral sucker and ovary. The levels of cytokines, nitrogen monoxide (NO), 5-hydroxytryptamine (5-HT) and specific antibodies were measured using kits or soluble worm antigens. Hematological indicators on day 0 were analyzed in mice that received PZQ on days -15, -18, -19, -20, -21 and -22. The PZQ concentrations in plasma and blood cells were monitored using high performance liquid chromatography (HPLC). The effective dose was found to be two oral administrations (interval of 24 h) at 300 mg/kg body weight (BW) or one injection at 200 mg/kg BW, and the protection period of PZQ injection was 18 days. The optimal preventive effect was observed at two days post-administration, with a >92% worm reduction rate and significant worm reduction until 21 days after administration. Adult worms from PZQ-pretreated mice were runtish showing a shorter length, smaller organs and fewer eggs in the uteri of females. Detection of cytokines, NO, 5-HT and hematological indicators showed that PZQ induced immune-physiological changes, including higher levels of NO, IFN-γ and IL-2, and a lower level of TGF-β. No significant difference in the anti-S. japonicum specific antibody levels was observed. The PZQ concentrations in plasma and blood cells 8 and 15 days post-administration were lower than the detection limit. Our results confirmed that pretreatment with PZQ promotes the protection of mice against S. japonicum infection within 18 days. Although we observed some immune-physiological changes in the PZQ-pretreated mice, the exact mechanisms involved in the preventive effect require further study.

Recent approaches in nanocarrier-based therapies for neglected tropical diseases

Neglected tropical diseases (NTDs) remain major public health problems in developing countries. Reducing the burden of NTDs requires sustained collaborative drug discovery efforts to achieve the goals of the new NTDs roadmap launched by the World Health Organization. Oral drugs are the most convenient choice and usually the safest and least expensive. However, the oral use of some drugs for NTDs treatment has many drawbacks, including toxicity, adverse reactions, drug resistance, drug low solubility, and bioavailability. Since there is an imperative need for novel and more effective drugs to treat the various NTDs, in recent years, several compound-loaded nanoparticles have been prepared with the objective of evaluating their application as an oral drug delivery system for the treatment of NTDs. This review focuses on the various types of nanoparticle drug delivery systems that have been recently used against the major NTDs caused by parasites such as leishmaniasis, Chagas disease, and schistosomiasis. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Infectious Disease.

Potential application of nanotechnology in the treatment, diagnosis, and prevention of schistosomiasis

Schistosomiasis is one of the neglected tropical diseases that affect millions of people worldwide. Globally, it affects economically poor countries, typically due to a lack of proper sanitation systems, and poor hygiene conditions. Currently, no vaccine is available against schistosomiasis, and the preferred treatment is chemotherapy with the use of praziquantel. It is a common anti-schistosomal drug used against all known species of Schistosoma. To date, current treatment primarily the drug praziquantel has not been effective in treating Schistosoma species in their early stages. The drug of choice offers low bioavailability, water solubility, and fast metabolism. Globally drug resistance has been documented due to overuse of praziquantel, Parasite mutations, poor treatment compliance, co-infection with other strains of parasites, and overall parasitic load. The existing diagnostic methods have very little acceptability and are not readily applied for quick diagnosis. This review aims to summarize the use of nanotechnology in the treatment, diagnosis, and prevention. It also explored safe and effective substitute approaches against parasitosis. At this stage, various nanomaterials are being used in drug delivery systems, diagnostic kits, and vaccine production. Nanotechnology is one of the modern and innovative methods to treat and diagnose several human diseases, particularly those caused by parasite infections. Herein we highlight the current advancement and application of nanotechnological approaches regarding the treatment, diagnosis, and prevention of schistosomiasis.

The Effect of Different Formulations of Praziquantel in Reducing Worms in the Prepatent Period of Schistosomiasis in Murine Models

Schistosomiasis is a widely distributed parasitic disease and one of the most important neglected tropical diseases globally, for which Praziquantel® (PZQ) is the only available treatment. In this context, tests with new PZQ formulations become relevant for disease control. This study evaluated the effects of PZQ treatment in the prepatent phase of schistosomiasis using two formulations: nanoencapsulated (PZQ-NANO) and active pharmaceutical ingredient (PZQ-API). Five experimental groups were established, for which the following serological parameters were evaluated: ALT, AST, ALP, and TP. Animals treated with PZQ-API at 15 and 30 days post-infection showed decreased eggs per gram of feces (EPG) compared to untreated infected animals. The same animals showed reductions of 63.6 and 65.1%, respectively, at 60 days post-infection. Animals treated with PZQ-NANO experienced no significant changes in EPG at any time of observation. Animals treated with either PZQ-API or PZQ-NANO had higher ALT and AST levels in the patent period (60 and 90 days post-infection). Treatment with PZQ, either API or NANO, at 15 days post-infection reduced AST, ALT, and TP levels. It is concluded that prepatent treatment with PZQ-API can reduce the parasite load of infected animals and that treatment at 15 days post-infection can prevent increased serum levels of ALT, AST, and TP.

Recent trends in praziquantel nanoformulations for helminthiasis treatment

INTRODUCTION

Infections caused by parasitic flatworms impose a considerable worldwide health burden. Recently, World Health Organization launched its roadmap for neglected diseases for the period 2021 to 2030 and oral treatment with praziquantel (PZQ) in tablet form is the main drug therapy for combating these diseases, but its use is limited by many drawbacks, including the high therapeutic dose due to the drug's low solubility and bioavailability. Among the strategies to improve PZQ performance, the use of drug nanocarriers has been cited as an interesting approach to overcome these pharmacological issues.

AREAS COVERED

This review focuses on the various types of nanomaterials (polymeric, lipidic, inorganic nanoparticles, and nanocrystals) which have been recently used to improve PZQ therapy. In addition, recent advances in PZQ nanoformulations, developed to overcome the barriers of the conventional drug are described.

EXPERT OPINION

Considering the poor rate of discovery in the anthelmintic segment observed in recent decades, the effective management of existing drugs has become essential. The application of new strategies based on nanotechnology can extend the useful life of PZQ in new and more effective formulations. Pharmaceutical nanotechnology can solve the pharmacokinetic challenges characteristic of PZQ and improve its solubility and bioavailability.

In vivo praziquantel efficacy of Schistosoma japonicum over time: A systematic review and meta-analysis

Praziquantel (PZQ), the only choice of chemotherapy for schistosomiasis recommended by World Health Organization (WHO), has been widely used over 40 years. The long-term, and rapid expansion of, PZQ use for disease control across a large populations continues to raise concern regarding the potential for emergence and establishment of drug resistance. Recent research has also proposed that the long survival and low sensitivity of unpaired worms, derived from either incomplete treatment cure rates or single-sex schistosome infections within final hosts, could exacerbate the risk of PZQ resistance (PZQ-R) emerging. With the aim of assessing whether PZQ efficacy amongst S. japonicum may have changed over time in China, we performed a unique systematic review and meta-analyses on datasets which evaluated the efficacy of PZQ via laboratory assays of field S. japonicum isolates on experimental mice over time. Relevant published literatures from four electronic bibliographic databases and lists of article references were searched. Two indexes, d, a measure used in meta-analyses for worm burden difference between two groups, and r, a traditional measure for worm reduction percentage after treatment but without considering sample size were calculated for each study. A total of 25 papers including 127 experimental studies with eligible data on 2230 mice were retrieved. The pooled d (D) was 3.91 (3.56-4.25) and pooled r (R) was 54.52% (52.55%-56.52%). D significantly increased over time, whereas R non-significantly decreased; both estimates were significantly associated with the total drug dose. Such findings suggested no evidence of PZQ-R emergence S. japonicum to date. However, we consider the potential role of parasite origins, PZQ dosage, and single versus mixed gender infections of the results published to date, and the avenues now needed for further research.