In vitro and in vivo treatments of Echinococcus granulosus with Huaier aqueous extract and albendazole liposome

Therapeutic effect of curcumin nanoemulsion on cystic echinococcosis in BALB/c mice: a computerized tomography (CT) scan and histopathologic study evaluation

BACKGROUND

This study aimed to determine the therapeutic efficacy of curcumin nanoemulsion (CUR-NE) in mice infected with Echinococcus granulosus sensu stricto protoscoleces.

METHODS

Forty-two inbred BALB/c mice were divided into seven groups of six animals each. Six groups were inoculated intra-peritoneally with 1500 viable E. granulosus protoscoleces, followed for six months and used as infected groups. The infected groups were named as: CEI1 to CEI6 accordingly. The 7th group was not inoculated and was named cystic echinococcosis noninfected group (CENI7). CEI1 and CEI2 groups received 40 mg/kg/day and 20 mg/kg/day curcumin nanoemulsion (CUR-NE), respectively. CEI3 received nanoemulsion without curcumin (NE-no CUR), CEI4 received curcumin suspension (CUR-S) 40 mg/kg/day, CEI5 received albendazole 150 mg/kg/day and CEI6 received sterile phosphate-buffered saline (PBS). CENI7 group received CUR-NE 40 mg/kg/day. Drugs administration was started after six months post-inoculations of protoscoleces and continued for 60 days in all groups. The secondary CE cyst area was evaluated by computed tomography (CT) scan for each mouse before treatment and on the days 30 and 60 post-treatment. The CT scan measurement results were compared before and after treatment. After the euthanasia of the mice on the 60th day, the cyst area was also measured after autopsy and, the histopathological changes of the secondary cysts for each group were observed. The therapeutic efficacy of CUR-NE in infected groups was evaluated by two methods: CT scan and autopsied cyst measurements.

RESULTS

Septal calcification in three groups of infected mice (CEI1, CEI2, and CEI4) was revealed by CT scan. The therapeutic efficacy of CUR-NE 40 mg/kg/day (CEI1 group) was 24.6 ± 26.89% by CT scan measurement and 55.16 ± 32.37% by autopsied cysts measurements. The extensive destructive effects of CUR-NE 40 mg/kg/day (CEI1 group) on the wall layers of secondary CE cysts were confirmed by histopathology.

CONCLUSION

The current study demonstrated a significant therapeutic effect of CUR-NE (40 mg/kg/day) on secondary CE cysts in BALB/c mice. An apparent septal calcification of several cysts revealed by CT scan and the destructive effect on CE cysts observed in histopathology are two critical key factors that suggest curcumin nanoemulsion could be a potential treatment for cystic echinococcosis.

Antiparasitic Effects of Asteraceae Species Extracts on Echinococcus granulosus s.s

Cystic echinococcosis is a zoonotic disease caused by the parasite Echinococcus granulosus sensu lato (s.l.), which is worldwide distributed and causes long-lasting infections in animals and humans. The existing treatment is limited to the use of benzimidazoles, mainly albendazole (ABZ). However, it has unwanted side effects and its efficacy is about 50%. The Asteraceae family includes plants that have therapeutic applications (medicinal species) and has an important role in new drug development. The species belonging to a different genus of this family show a wide range of anti-inflammatory, antimicrobial, antioxidant, hepatoprotective, and antiparasitic activities, among others. The aim of the present study was to evaluate the in vitro efficacy of extracts of four Asteraceae species against protoscoleces of E. granulosus sensu stricto (s.s.). On the other hand, the Stevia aristata extract was assessed on the murine cyst of E. granulosus (s.s.) and the efficacy of S. aristata extract was investigated in a murine model of CE. Stevia satureiifolia, S. aristata, Grindelia pulchella, and G. chiloensis extracts at 100 μg/mL caused a decrease in protoscoleces viability; however, S. aristata extract produced the greatest in vitro protoscolicidal effect. After 20 days of treatment with the highest concentration (100 μg/mL) of S. aristata extract, protoscoleces viability decreased to 0%. The tegumental changes observed by scanning electron microscopy were consistent with the reduction in vitality. The collapse of the germinal layer was registered in 60 ± 5.8% and 83.3 ± 12.0% of cysts treated during 4 days with 50 and 100 μg/ml, respectively. The half maximal effective concentration (EC50) value of the S. aristata extract against E. granulosus (s.s.) cysts was 47.86 μg/mL (96 h). The dosage of infected animals with the 50 mg kg⁻¹ dose of S. aristata extract resulted in a significant reduction in cyst weight in comparison with the control group. In conclusion, S. aristata extract was demonstrated to exert a marked effect, both in vitro and in the murine model.

Anthelmintic activity of Stevia multiaristata extract against Echinococcus granulosus sensu stricto

Cystic echinococcosis is a zoonotic disease caused by the larval stage of the parasite Echinococcus granulosus sensu lato. The available anti-parasitic treatment is mostly limited to a continuous administration of albendazole. However, due to its numerous side-effects and efficacy of around 50%, there is a need to find new drugs to improve the treatment for this disease. In the current study, the in vitro and in vivo efficacy of a Stevia multiaristata extract against E. granulosus sensu stricto (s.s.) was demonstrated. Stevia multiaristata extract (100 and 50 μg mL−1) caused a quick viability decrease on protoscoleces which was consistent with the observed tegumental alterations. Loss of turgidity was detected in 95 ± 3.4% of cysts incubated with S. multiaristata extract during 2 days (100 μg mL−1) and the collapse of the germinal layer was observed in 60 ± 9.3% of cysts treated with 100 μg mL−1 of the S. multiaristata extract during 4 days. The half maximal effective concentration value was 69.6 μg mL−1 and the selectivity index for E. granulosus s.s. cysts was 1.9. In this clinical efficacy study, the treatment of infected mice with the S. multiaristata extract (50 mg kg−1) caused a significant decrease in the weight of the cysts compared with the control group. These results coincided with the tissue damage observed in the cysts at the ultrastructural level. In conclusion, we observed high protoscolicidal and cysticidal effects, and significant reduction in the weight of the cysts in experimentally infected mice following treatment with the S. multiaristata extract.

Assessment of the Therapeutic Efficacy of Silver Nanoparticles against Secondary Cystic Echinococcosis in BALB/c Mice

Background: Cystic echinococcosis (CE) is a highly prevalent parasitic disease resulting from the hydatid cyst of Echinococcus granulosus. It is also described as a zoonotic disease and considered a neglected tropical infection. Aim: This study assessed the antiparasitic activity of silver nanoparticles (AgNPs), against E. granulosus infection in BALB/c mice. Methods: The green synthesis of AgNPs was accomplished using Zizyphus spina-christi leaves. AgNPs were orally administered to BALB/c mice for acute short-term toxicity evaluation, in doses of 50 mg, 100 mg, 200 mg, and 300 mg/kg, and observations for toxic signs were carried out at 24, 48 h, and 14 days, continuously. Moreover, a total of 20 mice divided into two groups were intraperitoneally administered with 1500 viable protoscoleces for secondary hydatidosis infection. Results: The results showed that AgNPs did not induce any adverse effects or signs and no death, in either group of mice. The histopathological findings in the liver, kidneys, and intestine of the mice administered with AgNPs revealed mild histological effects compared with the control ones. The treated-infected mice showed a change in the appearance of the liver hydatid cysts from hyaline to milky cloudy compared with the untreated infected mice. Conclusion: Biosynthesized AgNPs showed anti-hydatic effects and are suggested as anti-echinococcal cyst treatment.

Silybum marianum ethanolic extract: in vitro effects on protoscolices of Echinococcus granulosus G1 strain with emphasis on other Iranian medicinal plants

BACKGROUND

Cystic echinococcosis (CE), is a parasitic zoonosis caused by Echinococcus granulosus (E. granulosus) larvae in liver and lungs of both humans and animals. Surgical intervention is the mainstay for CE treatment, using scolicidal agents that inactivate live protoscolices. This study evaluated the scolicidal effects of Silybum marianum ethanolic extract and its combination with albendazole in vitro for the first time. Moreover, in a literature review, we investigated the effects of a wide range of Iranian medicinal plants on protoscolices of E. granulosus.

METHODS

S. marianum ethanolic extract was prepared and high-performance liquid chromatography (HPLC) analysis was used to establish the proportions of its component compounds in the extract. Cytotoxicity was evaluated in mouse macrophage cells (J774A.1 cell line) using MTT method. Next, the scolicidal activity of the extract alone and combined with albendazole was tested as triplicate at various concentrations incubated for 5, 10, 20, 30, and 60 min. Finally, protoscolex viability was determined using 0.1% eosin as a vital stain. PCR-RFLP and DNA sequencing techniques were used to characterize the genotype of E. granulosus.

RESULTS

HPLC analysis showed that S. marianum ethanolic extract contained mostly silydianin (14.41%), isosilybin A (10.50%), and silychristin (10.46%). The greatest scolicidal effects were obtained with the combination of S. marianum with albendazole (79%), S. marianum ethanolic extract alone (77%) and albendazole (69%), at a concentration of 500 μg/ml for 60 min, respectively (P < 0.05). Molecular analysis showed that all the cysts used were G1 genotype.

CONCLUSION

The data suggest that S. marianum ethanolic extract is a potential scolicide in vitro; however, further investigations are required to determine its efficacy in vivo.

Scolicidal and Apoptotic Activities of 5-hydroxy-1, 4-naphthoquinone as a Potent Agent against Echinococcus granulosus Protoscoleces

Cystic hydatid disease (CHD) is a zoonotic disease with different clinical stages caused by the larval stage of the cestode Echinococcus granulosus. It is important to highlight as a public health problem in various regions of the world. In the current study, the efficacy and apoptotic activity of the liposomal system containing juglone (5-hydroxy-1,4-naphthoquinone) were assessed against protoscoleces (PSCs) in vitro. To this aim, firstly, liposomal vesicles were prepared by the thin-film method. Their physico-chemical features were assessed using Zeta-Sizer and Scanning Electron Microscope (SEM). Subsequently, various concentrations (50, 100, 200, 400, and 800 μg/mL) of juglone nanoliposomes at different exposure times (15, 30, 60, and 120 min) were used against PSCs. Results showed that juglone nanoliposomes at all tested concentrations induced scolicidal effect, however, 800 μg/mL and 400 μg/mL of juglone nanoliposomes could reach 100% mortality in 60 and 120 min, respectively. Additionally, we found that caspase-3 mRNA expression was higher in PSCs treated with juglone nanoliposomes compared to control groups (p < 0.001). Therefore, juglone nanoliposomes are suggested to have a more potent apoptotic effect on PSCs. Generally, optimized doses of juglone nanoliposomes could display significant scolicidal effects. Moreover, further in vivo studies are required to evaluate the efficacy of this nanoliposome.

Research Progress on the Anti-Cancer Molecular Mechanisms of Huaier

Huaier (Trametes robiniophila Murr), a Chinese traditional herb of medicine, has demonstrated promising curative effects in clinical treatment for various tumors. There are documented experiments showing the biological functions of Huaier with its antineoplastic molecular mechanisms: restraining proliferation and metastasis, arresting cell cycle, inducing apoptosis, pyrosis, and autophagy, anti-intratumoral angiogenesis, attenuating characteristics of tumor stem-like cells, interfering with the function of the tumor-related immune system, reversing drug resistance, and enhancing the sensitivity to chemotherapeutic drugs, etc. In addition, studies suggest that non-coding RNA (ncRNA) acts a pivotal part in cancer occurrence and development, and demonstrates that Huaier adjusts the performance of certain lncRNA (long non-coding RNA) and proceeds to affect the microRNA and its target genes, rendering an anti-tumor effect. Huaier also modulates the expression of lncRNA to attenuate the activity of ncRNA-sponged microRNA and then inhibits the expression of downstream target genes. We summarize and illustrate the experimentally confirmed anti-cancer molecular mechanisms of Huaier, to inspire new ideas for researchers in relevant fields.

Albendazole solid dispersions against alveolar echinococcosis: a pharmacotechnical strategy to improve the efficacy of the drug

Alveolar echinococcosis is a neglected parasitic zoonosis caused by Echinococcus multilocularis. The pharmacological treatment is based on albendazole (ABZ). However, the low water solubility of the drug produces a limited dissolution rate, with the consequent failure in the treatment of the disease. Solid dispersions are a successful pharmacotechnical strategy to improve the dissolution profile of poorly water-soluble drugs. The aim of this work was to determine the in vivo efficacy of ABZ solid dispersions using poloxamer 407 as a carrier (ABZ:P407 solid dispersions (SDs)) in the murine intraperitoneal infection model for secondary alveolar echinococcosis. In the chemoprophylactic efficacy study, the ABZ suspension, the ABZ:P407 SDs and the physical mixture of ABZ and poloxamer 407 showed a tendency to decrease the development of murine cysts, causing damage to the germinal layer. In the clinical efficacy study, the ABZ:P407 SDs produced a significant decrease in the weight of murine cysts. In addition, the SDs produced extensive damage to the germinal layer. The increase in the efficacy of ABZ could be due to the improvement of water solubility and wettability of the drug due to the surfactant nature of poloxamer 407. In conclusion, this study is the basis for further research. This pharmacotechnical strategy might in the future offer novel treatment alternatives for human alveolar echinococcosis.

The combination of Cytokines and albendazole therapy for prophylaxis and treatment of experimental/hydatid cyst

Albendazole is appropriate chemotherapy for treatment and prophylaxis of cystic echinococcosis (CE). The recent studies show Cytokine therapy could be useful for chronic and progressive diseases, therefore, the use of cytokine in prophylaxis and treatment of hydatidosis could be considerable. The aim of this study is to evaluate the efficacy of interleukin-12 + interferon-gamma, in combination with albendazole for prophylaxis and treatment of CE in Balb/c mice. Albendazole and cytokines were administrated for prophylaxis and treatment in CE. The efficacy of this agents were determined by measuring of size, weight, number of cysts, histology and lymphocyte response. Lymphocyte stimulation index and production of interleukin-12 and interferon-gamma were measured by MTT assay and ELISA respectively. Combination of albendazole and cytokines was very effective for prophylaxis and treatment in experimental CE.

A preventive effect of the combination of albendazole and pomegranate peel aqueous extract treatment in cystic echinococcosis mice model: An alternative approach

To investigate the preventive effect of the combination of albendazole (ABZ) and pomegranate peel aqueous extract (PGE) treatment in cystic echinococcosis, we assess in vivo the antihydatic and the anti-inflammatory effects of the combination of ABZ/ PGE in cystic echinococcosis mice model. To evaluate the in vivo efficacy, mice were inoculated intraperitoneally with viable protoscolices and then treated with ABZ and/or PGE during cystic echinococcosis development. Mice were randomly allocated into eight groups: ABZ/CE group, PGE/CE group, (ABZ+PGE)/CE group, CE group, and control groups (Ctrl, PBS, ABZ, and PGE groups). Drugs in diverse treated groups were orally administered daily during CE development for two months. Mice were then euthanized and associated indications were investigated to evaluate the therapeutic efficacy. Cyst development and hepatic damage were macroscopically and histologically analyzed. The hepatic expression of iNOS, TNF-α, NF-κβ, vimentin, and CD68 was examined. Interestingly, the association of ABZ and PGE enhanced a significant reduction of the rate of hydatid cyst growth inhibition in comparison to the infected or ABZ-treated groups. This effect was strongly related to the histological structure of liver improvement. A significant iNOS, TNF-α, NF-κβ, vimentin, and CD68 decrease expression was observed in liver tissue of (ABZ+PGE)-treated group compared with infested and ABZ-treated groups. PGE treatment indicates a significant beneficial additive antihydatic effect with a reduction of the liver side effects. The combination of albendazole and PGE treatment is more efficient and suggests its potential preventive value against Echinococcus granulosus infection.

Therapeutic efficacy of nanocompounds in the treatment of cystic and alveolar echinococcoses: challenges and future prospects

Echinococcus granulosus sensu lato and E. multilocularis are the causative agents of life-threatening cystic and alveolar echinococcoses (CE and AE), respectively, which lead to serious public health concerns across the globe. Benzimidazoles (BMZs) are the drugs of choice for the treatment of human CE and AE. Presently, the chemotherapeutic failures of BMZs against CE and AE are caused by their low aqueous solubility, poor absorption, and consequently their erratic bioavailability. Among the BMZ compounds used for CE/AE treatment, albendazole (ABZ) and mebendazole (MBZ) are the only drugs licensed for human use. Nevertheless, the administration of these BMZs for a long period of time leads to undesirable adverse effects. Therefore, there is an urgent need for designing new formulations of BMZs with increased bioavailability. To bridge these therapeutic gaps, nanoparticle enantiomers of ABZ and drug delivery systems based on nanostructured entities currently provide an interesting new formulation of already existing drugs to improve the pharmacokinetic effects of BMZs. This study provides an overview of the tested nanocompounds against E. granulosus and E. multilocularis, including their effective dose, type of nanoparticles (NPs), assay setting, and therapeutic outcomes. This review suggests that BMZ derivatives loaded in NPs can significantly improve the scolicidal and cysticidal activities compared with single BMZ. Moreover, BMZ-loaded polymeric NPs show a tendency to increase mortality rate against protoscoleces and microcysts compared with metallic formulations, nanoemulsions, lipid nanocapsules, solid lipid NPs, liposomes, and nanocrystals. In the future, the use of the newly structured entities, attained by bridging ligands to the modified surface of NPs, as well as the electromagnetically produced nanodrugs could be helpful for developing fine-tuned formulations as an alternative to the already existing drugs against these neglected parasitic infections.

The importance of being parasiticidal… an update on drug development for the treatment of alveolar echinococcosis

The lethal disease alveolar echinococcosis (AE) is caused by the metacestode stage of the fox tapeworm Echinococcus multilocularis. Current chemotherapeutical treatment of AE relies on albendazole and mebendazole, with the caveat that these compounds are not parasiticidal. Drugs have to be taken for a prolonged period of time, often life-long, which can cause adverse effects and reduces the patients' quality of life. In some individuals, benzimidazoles are inactive or cause toxicity, leading to treatment discontinuation. Alternatives to benzimidazoles are urgently needed. Over the recent years, in vivo and in vitro models for low-to-medium throughput drug discovery against AE have been set in place. In vitro drug tests include the phosphoglucose-isomerase (PGI) assay to measure physical damage induced to metacestodes, and viability assays to assess parasiticidal activity against metacestodes and stem cells. In vitro models are also employed for studies on mechanisms of action. In vivo models are thus far based on rodents, mainly mice, and benefits could be gained in future by comparative approaches in naturally infected dogs or captive monkeys.

For the identification of novel drugs against AE, a rare disease with a low expected market return, drug-repurposing is the most promising strategy. A variety of chemically synthesized compounds as well as natural products have been analyzed with respect to in vitro and/or in vivo activities against AE. We here review and discuss the most active of these compounds including anti-infective compounds (benzimidazoles, nitazoxanide, amphotericin B, itraconazole, clarithromycin, DB1127, and buparvaquone), the anti-infective anti-malarials (artemisinin, ozonids, mefloquine, and MMV665807) and anti-cancer drugs (isoflavones, 2-methoxyestradiol, methotrexate, navelbine, vincristine, kinase inhibitors, metallo-organic ruthenium complexes, bortezomib, and taxanes). Taking into account the efficacy as well as the potential availability for patients, the most promising candidates are new formulations of benzimidazoles and mefloquine. Future drug-repurposing approaches should also target the energy metabolism of E. multilocularis, in particular the understudied malate dismutation pathway, as this offers an essential target in the parasite, which is not present in mammals.

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Benzimidazoles are used to treat AE, but new drugs are needed.

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New drugs against AE can be identified by drug repurposing.

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Drugs against other infectious diseases and cancer can be repurposed against AE.

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Most promising are new formulations of benzimidazoles and mefloquine.

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Future approaches should include targeting the energy metabolism of the parasite.

Albendazole-lipid nanocapsules: Optimization, characterization and chemoprophylactic efficacy in mice infected with Echinococcus granulosus

Cystic echinococcosis (CE), which is caused during the metacestode larval stage of Echinococcus granulosus, is a life-threatening disease and is very difficult to treat. At present, the FDA-approved antihelmintic drugs are mebendazole (MBZ), albendazole (ABZ) and its principal metabolite ABZ sulfoxide (ABZSO), but as these have a therapeutic efficacy over 50%, underlining the need for new drug delivery systems. The aim of this work was the optimization and characterization of previously developed ABZ lipid nanocapsules (ABZ-LNCs) and evaluate their efficacy in mice infected with E. granulosus. LNCs were prepared by the phase inversion technique and characterized in terms of size, surface charge, drug loading, and in vitro stability followed by an in vivo proof-of-concept using a murine model infected with E. granulosus. Stable particle dispersions with a narrow size distribution and high efficiency of encapsulation (≥90%) were obtained. ABZ-LNCs showed a greater chemoprophylactic efficacy than ABZ suspension administered by the oral route as 4 out of the 10 ABZ-LNCs treated mice did not develop any cysts, whereas the infection progressed in all mice from the ABZ suspension group. Regarding the ultrastructural studies of cysts, mice treated with ABZ-LNCs or ABZ suspension revealed changes in the germinal layer. However, the extent of the damage appeared to be greater after ABZ-LNC administration compared to the suspension treatment. These results suggest that ABZ-LNCs could be a promising novel candidate for ABZ delivery to treat CE.

Therapeutic and immunoregulatory effects of water-soluble alkaloids E2-a from Sophora moorcroftiana seeds as a novel potential agent against echinococcosis in experimentally protoscolex-infected mice

Novel compounds and more efficient treatment options are urgently needed for the treatment of cystic echinococcosis (CE), which is caused by Echinococcus granulosus. The decoction of Sophora moorcroftiana (Fabaceae) has been used to treat parasitosis for years in traditional Tibetan medicine. The aim of this study was to screen insecticidal water-soluble alkaloids from S. moorcroftiana seeds and evaluate the therapeutic effects against CE and the immune response induced by the alkaloidal fraction. Low polarity compounds (E2-a) were isolated from water-soluble alkaloid (E2) and matrine and sophocarpine were identified as major components. The E2-a fraction was more effective against protoscoleces than other constituents from S. moorcroftiana. After 20 weeks of secondary infection with protoscoleces, mice were orally treated with E2-a (100 mg/kg/day) for 6 weeks to evaluate therapeutic and immunoregulatory activities. Compared with the untreated group, E2-a treatment induced a significant reduction in cyst weight (mean 2.93 g) (p < 0.05) and an impaired ultrastructural modification of the cyst. Interestingly, the application of E2-a resulted in a significant increased frequency of CD3⁺CD4⁺ T-cell subsets and decreased frequency of CD3⁺PD-1⁺ T-cell subsets, compared with protoscolece-infected mice without treatment. The E2-a fraction of S. moorcroftiana can inhibit the cyst development of CE and boost the specific immune response by reducing the expression of PD-1 and accelerate the cytokine secretion of antigen-specific T-cells. All data suggest the E2-a fraction from S. moorcroftiana seeds may be used as a new potential therapeutic option against E. granulosus infection.

Progress in the pharmacological treatment of human cystic and alveolar echinococcosis: Compounds and therapeutic targets

Human cystic and alveolar echinococcosis are helmintic zoonotic diseases caused by infections with the larval stages of the cestode parasites Echinococcus granulosus and E. multilocularis, respectively. Both diseases are progressive and chronic, and often fatal if left unattended for E. multilocularis. As a treatment approach, chemotherapy against these orphan and neglected diseases has been available for more than 40 years. However, drug options were limited to the benzimidazoles albendazole and mebendazole, the only chemical compounds currently licensed for treatment in humans. To compensate this therapeutic shortfall, new treatment alternatives are urgently needed, including the identification, development, and assessment of novel compound classes and drug targets. Here is presented a thorough overview of the range of compounds that have been tested against E. granulosus and E. multilocularis in recent years, including in vitro and in vivo data on their mode of action, dosage, administration regimen, therapeutic outcomes, and associated clinical symptoms. Drugs covered included albendazole, mebendazole, and other members of the benzimidazole family and their derivatives, including improved formulations and combined therapies with other biocidal agents. Chemically synthetized molecules previously known to be effective against other infectious and non-infectious conditions such as anti-virals, antibiotics, anti-parasites, anti-mycotics, and anti-neoplastics are addressed. In view of their increasing relevance, natural occurring compounds derived from plant and fungal extracts are also discussed. Special attention has been paid to the recent application of genomic science on drug discovery and clinical medicine, particularly through the identification of small inhibitor molecules tackling key metabolic enzymes or signalling pathways.

Human cystic and alveolar echinococcosis (CE and AE), caused by the larval stages of the helminths Echinococcus granulosus and E. multilocularis, respectively, are progressive and chronic diseases affecting more than 1 million people worldwide. Both are considered orphan and neglected diseases by the World Health Organization. As a treatment approach, chemotherapy is limited to the use of benzimidazoles, drugs that stop parasite growth but do not kill the parasite. To compensate this therapeutic shortfall, new treatment alternatives are urgently needed. Here, we present the state-of-the-art regarding the alternative compounds and new formulations of benzimidazoles assayed against these diseases until now. Some of these new and modified compounds, either alone or in combination, could represent a step forward in the treatment of CE and AE. Unfortunately, few compounds have reached clinical trials stage in humans and, when assayed, the design of these studies has not allowed evidence-based conclusions. Thus, there is still an urgent need for defining new compounds or improved formulations of those already assayed, and also for a careful design of clinical protocols that could lead to the draw of a broad international consensus on the use of a defined drug, or a combination of drugs, for the effective treatment of CE and AE.

Natural products applied against hydatid cyst protoscolices: A review of past to present

Echinococcus granulosus is the causative agent of cystic echinococcosis (CE), which is distributed all around the world. CE is one of the most important global parasitic infectious diseases, both in humans and animals. This parasite causes hydatid cysts that can be lodge at different organs of host such as liver, lung even in heart and brain which may lead to death. Presently, numerous scolicidal chemical agents have been administrated for inactivation of the hydatid cyst contents. Because of increasing resistance and adverse effects of medications include abnormalities of liver function, abdominal pain, diarrhea, nausea, vomiting, dizziness, and headache; there is a need to find alternative therapies either with the least or without side effects. Recently, there is a high tendency among researchers to evaluate and present herbal plants as alternative option due to being inexpensive, easy available, low side effects and toxicity. Till now, many efforts have been conducted on herbal extracts against protoscolices of hydatid cysts throughout the world. Therefore, the current review systematically searched the following electronic databases: PubMed, Science Direct, Scopus, and Google Scholar on published papers according to the keywords. In addition, a comprehensive list of medicinal plants was prepared and some of these herbal plants which showed the best efficacy and promising results are discussed elaborately.

Anthelmintic effects of Oroxylum indicum stem bark extract on juvenile and adult stages of Hymenolepis diminuta (Cestoda), an in vitro and in vivo study

Worldwide, traditional usage of herbal medicines is a common practice to treat various parasitic infections. In India, bark decoction of Oroxylum indicum (L.) Kurz. (Bignoniaceae) is used as a traditional medicine to cure intestinal-helminthic infections. This study investigated the anthelmintic efficacy of methanolic bark extract of O. indicum on Hymenolepis diminuta (Cestoda), using both in vitro and in vivo methods. Utilizing a mini-questionnaire, first, we collected information about the pattern of anthelmintic use of this plant. Later, in vitro efficacy of extract was tested at 10, 20 and 30 mg/ml on both the artificially excysted juveniles and adult H. diminuta worms. Herein, scanning electron microscopy (SEM) was also utilized to determine the possible effects of extract on tegumental surfaces of juvenile and adult cestode. In vivo, extract was tested at 250, 500 and 1000 mg/kg in H. diminuta albino rat model, against juvenile and adult cestode. Praziquantel (PZQ) served as reference drug in anthelmintic assays. The acute toxicity of extract was determined as per the OECD guidelines. The field questionnaire data revealed that 78 % of people in the area use O. indicum stem bark against intestinal helminths, and of these, 75 % of people also believed it highly efficacious anthelmintic remedy. In vitro testing of extract revealed significant effects on juvenile worms, and 30 mg/ml of extract caused mortality of juveniles at the initial period (0.25 ± 0.00 h). Conversely, PZQ (1 mg/ml) showed paralysis and mortality of juvenile cestodes in 0.44 ± 0.04 and 1.11 ± 0.06 h, respectively. As determined by SEM, in vitro exposure to extract showed substantial effects on both juveniles and adult worms in the form of wrinkled scolex, distorted tegument and eroded microtriches. In vivo study revealed better efficacy of extract against juveniles than adult stages of parasite. Treatment of rats with 1000 mg/kg of extract caused 79.3 % reduction in EPG counts and 70.8 % of reduction in worm counts, which compared well to PZQ efficacy. In acute toxicity study, administration of a single oral dose of 2000 mg/kg of extract to mice did not cause any signs of toxicity or mortality within 2-week observation. Hence, the LD50 of extract was estimated to be greater than 2000 mg/kg. In conclusion, the bark extract of O. indicum possesses concentration-dependent effects against the larval and adult H. diminuta worms, and thus the extract holds promise in the control of intestinal helminthiases. This also supports the common belief of people about the reputation of this plant as anthelmintic in traditional medicine. There is a need to standardize the formulations of this plant for their possible use as standardized herbal anthelmintic agents in the future.

Arsenic trioxide negatively affects Echinococcus granulosus

Spillage of cyst contents during surgery is the major cause of recurrences of hydatidosis, also called cystic echinococcosis (CE). Currently, many scolicidal agents are used for inactivation of the cyst contents. However, due to complications in the use of those agents, new and more-effective treatment options are urgently needed. The aim of this study was to investigate the in vitro efficacy of arsenic trioxide (ATO) against Echinococcus granulosus protoscolices. Protoscolices of E. granulosus were incubated in vitro with 2, 4, 6, and 8 μmol/liter ATO; viability of protoscolices was assessed daily by microscopic observation of movements and 0.1% eosin staining. A small sample from each culture was processed for scanning and transmission electron microscopy. ATO demonstrated a potent ability to kill protoscolices, suggesting that ATO may represent a new strategy in treating hydatid cyst echinococcosis. However, the in vivo efficacy and possible side effects of ATO need to be explored.

Huaier Extract Induces Autophagic Cell Death by Inhibiting the mTOR/S6K Pathway in Breast Cancer Cells

Huaier extract is attracting increased attention due to its biological activities, including antitumor, anti-parasite and immunomodulatory effects. Here, we investigated the role of autophagy in Huaier-induced cytotoxicity in MDA-MB-231, MDA-MB-468 and MCF7 breast cancer cells. Huaier treatment inhibited cell viability in all three cell lines and induced various large membranous vacuoles in the cytoplasm. In addition, electron microscopy, MDC staining, accumulated expression of autophagy markers and flow cytometry revealed that Huaier extract triggered autophagy. Inhibition of autophagy attenuated Huaier-induced cell death. Furthermore, Huaier extract inhibited the mammalian target of the rapamycin (mTOR)/S6K pathway in breast cancer cells. After implanting MDA-MB-231 cells subcutaneously into the right flank of BALB/c nu/nu mice, Huaier extract induced autophagy and effectively inhibited xenograft tumor growth. This study is the first to show that Huaier-induced cytotoxicity is partially mediated through autophagic cell death in breast cancer cells through suppression of the mTOR/S6K pathway.

Scolicidal activity of biosynthesized silver nanoparticles against Echinococcus granulosus protoscolices

Cystic hydatid disease (CHD), a helminth infection with various clinical complications caused by the larval stage of the dog tapeworm Echinococcus granulosus is considered as a public health problem in different regions of the world. To date, scolicidal agents have been broadly applied for inactivation of the fertile cysts and these scolicidal agents have several side effects on patients. Therefore, the objective of this study was to evaluate the scolicidal efficacies of synthesized silver nanoparticles (AgNPs) derived from the aqueous aerial extract of Penicillium aculeatum against protoscolices of CHD in-vitro. Protoscolices were aseptically aspirated from infected livers of sheep with CHD. Various concentrations (0.025, 0.05, 0.1 and 0.15 mg/mL) of green synthesis of Ag-NPs and different exposure times (10, 30, 60 and 120 min) were used against protoscolices of CHD. Viability of protoscolices was confirmed by 0.1% eosin staining. The findings showed that the Ag-NPs at all concentrations have high scolicidal effects. The concentrations 0.1 and 0.15 mg/mL after 120 min of exposure times showed 83% and 90% mortality rate, respectively. The least scolicidal activity of biosynthesized Ag-NPs was 40% (0.025 mg/mL and 10 min). The current investigation indicated that applying biogenic Ag-NPs may be considered as a potential scolicidal agent for CHD surgery due to being economical, safer and non-toxic compared to the used chemical materials. However, further studies are required to evaluate the efficacy of Ag-NPs in vivo.

Huaier aqueous extract inhibits stem-like characteristics of MCF7 breast cancer cells via inactivation of hedgehog pathway

The theory of targeting cancer stem-like cells (CSCs) provides novel strategy for cancer treatment. In the present study, we examined the inhibitory effect of Huaier aqueous extract on eradicating breast cancer stem cells and explored the underlying mechanisms. Our data demonstrated that various concentrations of Huaier extract significantly decreased the viabilities, numbers, and sizes of mammospheres. After incubation with Huaier extract for 24 h, the clonogenicity of MCF7 cell line was obviously impaired, along with less holoclones. In addition, Huaier extract reduced the number of cells expressing CD44+/CD24- and decreased the level of stem cell markers (OCT-4, NESTIN, and NANOG). The hedgehog (Hh), notch, and Wnt/β-catenin pathways were essential stem cell signaling pathways involved in regulating CSC renewal and maintenance. We reported that the inhibitory effect of Huaier extract was partly depended on the inactivation of Hh pathway. These findings provided experimental evidence that Huaier extract was a promising therapeutic drug for eliminating the breast cancer stem cells.

Preventive and therapeutic effects of Zataria multiflora methanolic extract on hydatid cyst: an in vivo study

The phenolic compounds of Zataria multiflora extract, were identified by HPLC analysis. Gallic acid, catechin, caffeic acid, and quercetin were found to be the major phenolic compounds. Eighty healthy laboratory Balb/C mice were infected intraperitoneally by injection of 1500 viable protoscoleces and were divided into prevention (40 mice) and therapeutic (40 mice) groups. To prove the preventive effect of Z. multiflora extract on development of hydatid cyst, the 40 infected animals were allocated into three treatment groups including Z. multiflora (4 g/l in drinking water for 8 months), albendazole (150 mg/kg BW/day for 10 days) and untreated (control) group. To estimate the therapeutic effect of Z. multiflora extract on the hydatid cyst, after 8 months of infection, the infected mice were allocated into three experimental treatment groups including Z. multiflora (8 g/l in drinking water for 30 days), albendazole (300 mg/kg BW/day for 20 days) and untreated (control) group. At the end of the treatment period, all mice were euthanized and necropsied, the hydatid cysts were carefully removed, weighed and their size were recorded. Weight and size of the hydatid cysts significantly decreased (p<0.05) upon the treatment with Z. multiflora extract in both prevention and therapeutic groups. The germinal layer of the hydatid cysts recovered from the treated mice, either from the prevention or therapeutic group, were completely damaged at ultrastructural level by scanning electron microscopy.

In vitro treatments of Echinococcus granulosus with fungal chitosan, as a novel biomolecule

OBJECTIVE

To determined the antiparasitic activity of the isolated chitosan from Penicillium viridicatum, Penicillium aurantiogriseum and commercial chitosan against protoscolicidal of hydatid cysts were determined.

METHODS

After isolating chitosan from fungal cell walls, four concentrations (50, 100, 200, 400 μg/mL) of each type of prepared chitosan and commercial chitosan were used for 10, 30, 60, and 180 min, respectively.

RESULTS

Among different type of chitosan, commercial chitosan with the highest degree of deacetylation showed high scolicidal activity in vitro. Fungal chitosan could be recommended, as good as commercial chitosan, for hydatic cysts control.

CONCLUSIONS

It seems to be a good alternative to synthetic and chemical scolicidal.