Baiting not-owned dogs against Echinococcus granulosus: innovative tools for integrated control

Cystic echinococcosis (CE), caused by the larval stage of the cestode Echinococcus granulosus, is one of the most widespread zoonoses in Mediterranean countries. Baiting not-owned dogs with praziquantel (PZQ), due to their key role in the maintaining the transmission of CE, currently appears to be the most effective way to limit the transmission of CE, as well as an important aspect to introduce for the control of this parasitic disease. Therefore, this study aims to test 3 types of PZQ-based baits by evaluating different parameters (integrity over time, attractiveness and palatability for dogs, and mechanical resistance after release to different altitudes) and the bait acceptance in field by target animals, i.e. not-owned dogs, by using camera traps. The double PZQ-laced baits (with a double layer of highly palatable chews) showed the greatest resistance in the environment while also preserving the attractiveness and palatability up to 10 days, also withstood heights of 25 m, thus resulting as the most suitable also for drone delivery. The results on the field showed that most of the baits were consumed by not-owned dogs (82.2%), while the remaining were consumed by wild boars (8.9%), foxes (6.7%), badgers (1.1%) and hedgehogs (1.1%), confirming the specific and high attractiveness of the double PZQ-laced baits for the target population and highlights how an anthelmintic baiting programme may be a viable tool for the management of E. granulosus among free-ranging dog populations in endemic rural areas.

Comparison of the Scolicidal Activity of Two Leaves Extracts of Myrtus communis from Algeria Against Echinococcus granulosus Sensu Lato Protoscoleces

PURPOSE

During cystic echinococcosis surgery, the use of scolicidal agents such as hypertonic saline (20%) aims to reduce the risk of infection recurrence, but most of the used agents are associated with undesirable side effects. Therefore, the use of natural scolicidal agents such as medicinal plant extracts could reduce these medical issues. The present study aimed to compare in vitro the scolicidal activity between two extracts of the medicinal plant Myrtus communis from Algeria against Echinococcus granulosus sensu lato protoscoleces.

METHODS

The ethanolic and aqueous extraction of plant leaves was performed. Phytochemical analysis by gas chromatography-tandem mass spectrometry (GC-MS/MS), determination of total phenolic and flavonoid contents, and in vitro antioxidant activity by DPPH were evaluated for both extracts. Finally, the in vitro scolicidal activity was tested by different concentrations. The viability was evaluated by the eosin exclusion test.

RESULTS

The phytochemical analysis revealed 28 components for the ethanolic extract and 44 components for the aqueous extract. The major components were 2'-hydroxy-5'-methoxyacetophenone and 4-amino-2-methylphenol, respectively. The total phenolic and flavonoid contents were 45.9 ± 0.085 mg of gallic acid equivalent per g of extract (GAE/g E) and 16.5 ± 0.004 mg of quercetin equivalent per g (QE/g E) for the ethanolic extract, and 36.5 ± 0.016 mg GAE/g E and 18.2 ± 0.023 mg QE/g E for the aqueous extract, respectively. Furthermore, ethanolic and aqueous extracts of M. communis gave a value of IC50 = 0.009 ± 0.0004 mg/ml and IC50 = 0.012 ± 0.0003 mg/ml for the antioxidant activity, respectively. The in vitro scolicidal activity with concentrations of 50, 75, 100, and 150 mg/ml was tested for 5, 10, 15, and 30 min, and 5, 10, 15, 30, 60, 90, and 120 min for ethanolic and aqueous extracts, respectively. The mortality rate of protoscoleces at concentrations of 100 and 150 mg/ml was 98.8 and 100%, respectively, after 5 min of exposure to the ethanolic extract, while this rate was 100% at the same concentrations only after 60 min of exposure to the aqueous extract.

CONCLUSIONS

The ethanolic extract showed a stronger scolicidal activity against E. granulosus s.l protoscoleces than the aqueous extract. In the future, other investigations are necessary to elucidate the mechanism of action and the possible toxicity on human cells. Moreover, experimental animal studies are required to investigate the efficacy of different extracts of this plant and its components as natural anti-parasitic alternatives for the treatment of human cystic echinococcosis.

Assessing the Potential Apoptotic Effects of Different Hydatid Cyst Fluids on Human Healthy Hepatocytes and Hepatocellular Carcinoma Cells

Cystic Echinococcosis (CE) is a zoonotic infection caused by the larval form of Echinococcus granulosus in humans. Emerging evidence suggests an intriguing inverse association between E. granulosus infection and the occurrence of cancer. This study aimed to investigate the influence of diverse host-derived hydatid cyst fluids (HCF) with distinct genotypes on human liver hepatocytes (HC) and hepatocellular carcinoma cells (HepG2). Specifically, we examined their effects on cell proliferation, apoptosis sensitivity (BAX/BCL-2), apoptosis-related p53 expression, and the expression of cancer-related microRNA (hsa-miR-181b-3p). Cell proliferation assays, real-time PCR, and ELISA studies were conducted to evaluate potential anti-cancer properties. The findings revealed that animal-origin HCF (G1(A)) induced direct cell death by augmenting the susceptibility of HepG2 cells to apoptosis. Treatment with both G1(A) and G1(H) HCF sensitized HepG2 and HC cell lines to apoptosis by modulating the BAX/BCL-2 ratio, accompanied by upregulation of the p53 gene. Additionally, G1(A) HCF and human-derived HCFs (G1(H), G7(H)) reduced the expression of miR-181b-3p in HepG2 cells. Consequently, this study demonstrates the potential anti-cancer effect of HCF in HepG2 cells and provides the first comparative assessment of HCFs from human and animal sources with diverse genotypes, offering novel insights into this field.

Chemical Composition, Apoptotic Activity, and Antiparasitic Effects of Ferula macrecolea Essential Oil against Echinococcus granulosus Protoscoleces

Background: Today, the present protoscolicidals used to minimize the serious risks during hydatid cyst surgery are not completely safe and have various adverse side effects. The present study aimed to evaluate the chemical composition and apoptotic activity of Ferula macrecolea essential oil (FMEO) as well as its in vitro and ex vivo protoscolicidal effects against hydatid cyst protoscoleces. Methods: Gas chromatography/mass spectrometry (GC/MS) analysis was performed to determine the chemical composition of FMEO. Protoscoleces of hydatid cysts were collected from liver fertile hydatid cysts of infected sheep and were then treated with various concentrations of the essential oil (75, 150, and 300 µL/mL) for 5–60 min in vitro and ex vivo. Then, by using the eosin exclusion test, the viability of the protoscoleces was studied. The caspase-3-like activity of the FMEO-treated protoscoleces was also evaluated through the colorimetric protease assay Sigma Kit based on the manufacturer’s instructions. Results: According to GC/MS, the main constituents of the essential oil were terpinolene (77.72%), n-nonanal (4.47%), and linalool (4.35%), respectively. In vitro, the maximum protoscolicidal activity of FMEO was observed at the concentrations of 150 and 300 µL/mL, such that 100% of the protoscoleces were killed after 30 and 20 min of exposure, respectively. Based on the obtained findings, the results demonstrate that FMEO required a longer time to kill protoscoleces ex vivo; after 12 min of exposure to FMEO, only 13.4% of the protoscoleces remained alive. After 48 h of the treatment of protoscoleces, FMEO, in a dose-dependent manner and at doses of 75, 150, and 300 µL/mL, induced the activation of the caspase enzyme by 24.3, 35.3, and 48.3%, respectively. Conclusions: Our findings demonstrate the potent protoscolicidal effects of FMEO in vitro and ex vivo; however, further studies are required to assess the safety and the efficiency of FMEO as a promising scolicidal agent in a preclinical model and clinical setting.

Tacrolimus, a rapamycin target protein inhibitor, exerts anti-cystic echinococcosis effects both in vitro and in vivo

In view of a growing need for new treatment options for human cystic echinococcosis (CE), we aimed to investigate the efficacy of mTOR pathway inhibitors against CE in vitro and in vivo. Among the seven mTOR inhibitors evaluated, tacrolimus (TAC) showed significant dose- and time-dependent killing of cultured protoscoleces and cysts in vitro. Notably, the oral administration of TAC (4 mg/kg/day) to CE mice model highly effectively reduced both the weight and number of parasitic cysts. Transmission electron microscopy revealed that TAC destroys the ultrastructure of cysts, both in vitro and in vivo. Furthermore, TAC had no significant effect on blood glucose, body weight, liver, or kidney functions in mice. We further observed that the ATP levels and glucose content of cysts reduced upon TAC treatment, indicating that inhibiting mTORC1 activity possibly affects glucose metabolism in the cysts of mice. Based on our experimental data, TAC emerged as a promising anti-cyst drug that efficiently inhibits the growth of cysts.

Effects of Allium sativum on IFN-γ and IL4 concentrations in mice with cystic echinococcosis

The aim of the current investigation was to assess the impacts of methanolic extract of Allium sativum (MEAS) on IL-4 (a cytokine derived from Th2 cells) and IFN-ɣ (a cytokine derived from Th1 cells) levels in mice infected with Echinococcus granulosus. Sixty healthy BALB/c female mice were used in this study. Each animal was intraperitoneally injected with 1500 protoscoleces. The infected animals were randomly divided into six groups: albendazole (100 mg/kg), MEAS 10 (10 mg/kg), MEAS 20 (20 mg/kg), MEAS 40 (40 mg/kg), MEAS 80 (80 mg/kg) and control group with no treatment. The studied animals received albendazole and/or MEAS through drinking water for 30 days. Serum IFN-γ concentration significantly increased in the MEAS 20 and 80 groups in comparison to the control, albendazole and MEAS 10 groups (P < 0.05). The serum IL-4 level showed no significant difference between the trial groups. The findings of this study showed that MEAS at 20 and 80 mg/kg concentrations enhanced Th1 cell response in mice with cystic echinococcosis.

A systematic review of medicinal plants used against Echinococcus granulosus

Cystic echinococcosis (CE) is a zoonotic helminthiasis caused by different species of the genus Echinococcus, and is a major economic and public health concern worldwide. Synthetic anthelmintics are most commonly used to control CE, however, prolonged use of these drugs may result in many adverse effects. This study aims to discuss the in vitro/in vivo scolicidal efficacy of different medicinal plants and their components used against Echinococcus granulosus. Google Scholar, ScienceDirect, PubMed and Scopus were used to retrieve the published literature from 2000-2020. A total of 62 published articles met the eligibility criteria and were reviewed. A total of 52 plant species belonging to 22 families have been reported to be evaluated as scolicidal agents against E. granulosus worldwide. Most extensively used medicinal plants against E. granulosus belong to the family Lamiaceae (25.0%) followed by Apiaceae (11.3%). Among various plant parts, leaves (36.0%) were most commonly used. Essential oils of Zataria multiflora and Ferula asafetida at a concentration of 0.02, and 0.06 mg/ml showed 100% in vitro scolicidal activity after 10 min post application, respectively. Z. multiflora also depicted high in vivo efficacy by decreasing weight and size while also causing extensive damage to the germinal layer of the cysts. Plant-based compounds like berberine, thymol, and thymoquinone have shown high efficacy against E. granulosus. These plant species and compounds could be potentially used for the development of an effective drug against E. granulosus, if further investigated for in vivo efficacy, toxicity, and mechanism of drug action in future research.

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.

In vitro evaluation of the protoscolicidal effect of Eucalyptus globulus essential oil on protoscolices of hydatid cyst compared with hypertonic saline, povidone iodine and silver nitrate

OBJECTIVE

There are various protoscolicidal agents for inactivation of protoscoleces of hydatid cysts before and during surgical operation. The present study was aimed to evaluate the protoscolicidal effect of two concentrations of Eucalyptus globulus on protoscoleces of Echinococcus granulosus sensu lato under in vitro condition and to compare its efficacy with hypertonic saline, povidone iodine and silver nitrate.

METHODS

Live protoscoleces obtained from the liver of naturally infected sheep were exposed to 0.5% and 1% of Eucalyptus globulus essential oil, 5% hypertonic saline, 10% povidone iodine and 0.5% silver nitrate for 1 and 3minutes. Phosphate buffered saline was used as a negative control. One percent eosin staining method was used to test the viability of protoscoleces in different groups.

RESULTS

While the mean percentage of dead protoscoleces was 6.08% in the control group, the scolicidal power of 5% hypertonic saline was only 6.54% and 6.60% after 1 and 3min respectively. 0.5% E. globulus EO demonstrated 97.38% and 100% scolicidal activity after 1 and 3min respectively. The mean protoscolicidal power of 1% E. globulus EO, 10% povidone iodine and 0.5% silver nitrate was 100% after one minute.

CONCLUSIONS

According to the results of this study, E. globulus EO demonstrated high scolicidal power in a short period of time. Hence, this herbal product could be considered as a potent natural scolicidal agent that could be used before and during surgery of hydatid disease.

In Vitro Study on Protoscolicidal Effect of Methanolic Extract of Allium hirtifolium on Protoscoleces of Cystic Echinococcosis

BACKGROUND

Cystic echinococcosis/ hydatidosis is one of the most important parasitic zoonoses worldwide. Usually, surgery is used for the treatment of active cysts. Due to the risk of cyst rupture during surgery, a protoscolicidal agent is usually injected into the cyst before surgery to prevent secondary cyst formation in case of cyst rupture. Due to the side effects of chemical protoscolicidal agents attempts have been focused on herbal medicine. In this regard, Allium sativum has already been used; however, the protoscolicidal effect of Allium hirtifolium from Allium family has not been investigated, so far.

OBJECTIVE

The present study was conducted in order to assess the protoscolicidal effect of methanolic extract of Allium hirtifolium in different concentrations, temperature and exposure times. Cetrimide as a positive control and DMSO as a negative control were also used in this study.

METHODS

The viability of protoscoleces was determined by 0.1% eosin staining method.

RESULTS

The protoscolicidal effect of Allium hirtifolium on protoscoleces was as follows: The mean percent and standard deviation (SD) of protoscolicidal activity of 50 mg/ml concentration of Allium hirtifolium extract in room temperature at 10, 20, 30, 40 and 50 minutes of exposure was 5.88±2.39, 8.59±4.54, 11.82±5.81, 12.31±6.16and 16.96±8.42 respectively; while at 37°C it was 9.10±5.01, 11.52±7.36, 18.64±4.36, 27.07±6.57 and 38.15±12.80, respectively.

CONCLUSION

In conclusion, although Allium hirtifolium from Allium family is similar to Allium sativum; the protoscolicidal effect of its methanolic extract is not similar and less than A. sativum extract.

Efficiency of flubendazole-loaded mPEG-PCL nanoparticles: A promising formulation against the protoscoleces and cysts of Echinococcus granulosus

None of the existing drugs can effectively treat the human cystic echinococcosis. This study aimed to improve the efficacy of flubendazole (FLBZ) against the protoscoleces and cysts of Echinococcus granulosus by preparing polymeric FLBZ-loaded methoxy polyethylene glycol-polycaprolactone (mPEG-PCL) nanoparticles. The protoscoleces and microcysts were treated with FLBZ-loaded mPEG-PCL nanoparticles (FLBZ-loaded nanoparticles) and free FLBZ at the final concentrations of 1, 5, and 10 μg/mL for 27 and 14 days, respectively. The chemoprophylactic efficacy of the drugs was evaluated in experimentally infected mice. The nanoparticles were stable for 1 month, with an average size of 101.41 ± 5.14 nm and a zeta potential of -19.13 ± 2.56 mV. The drug-loading and entrapment efficiency of the FLBZ-loaded nanoparticles were calculated to be 3.08 ± 0.15% and 89.16 ± 2.93%, respectively. The incubation of the protoscoleces with the 10 μg/mL nano-formulation for 15 days resulted in 100% mortality, while after incubation with the 10 μg/mL free FLBZ, the viability rate of the protoscoleces was only 44.0% ± 5.22%. Destruction of the microcysts was observed after 7 days' exposure to the FLBZ-loaded nanoparticles at a concentration of 10 μg/mL. The in vivo challenge showed a significant reduction in the weight and number of the cysts (P <  0.05) in the mice treated with the FLBZ-loaded nanoparticles, yielding efficacy rates of 94.64% and 70.21%, correspondingly. Transmission electron microscopy revealed extensive ultrastructural damage to the cysts treated with the FLBZ-loaded nanoparticles. The results indicated that the FLBZ-loaded nanoparticles were more effective than the free FLBZ against the protoscoleces and cysts of E. granulosus both in vitro and in vivo.

Could beta-myrcene be an alternative to albendazole for the treatment of experimental cystic echinococcosis?

Echinococcus granulosus causes hydatidosis or cystic echinococcosis in humans and livestock. In humans, this disease can be managed with surgery, percutaneous treatment, chemotherapy and/or observation. The chemotherapeutic agents used and approved for treatment of hydatidosis are benzimidazoles. Because of the difficulties in achieving successful treatment, considerable efforts have been made to find new natural compounds against hydatid disease. Beta-myrcene is a monoterpene presented in the essential oils of different plants. It is the principal component of essential oil of Rosmarinus officinalis (rosemary). The goal of the present study was to evaluate the in vitro effects of beta-myrcene against germinal cells, protoscoleces and murine cyst of E. granulosus, as well also, investigate its chemoprophylactic activity in a murine model of cystic echinococcosis. For the in vitro assays, the parasites were incubated with beta-myrcene at 10, 5 and 1 μg/mL. The treatments were dose and time-dependent, and consistent with the observed morphological alterations. In the chemoprophylactic efficacy study, the effect of beta-myrcene was similar to albendazole, the reference drug for human echinococcosis treatment.

Estimating the prevalence of Echinococcus in domestic dogs in highly endemic for echinococcosis

BACKGROUND

Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are highly endemic in Xiji County of Ningxia Hui Autonomous Region (NHAR) in China where the control campaign based on dog de-worming with praziquantel has been undertaken over preceding decades. This study is to determine the current prevalence of Echinococcus granulosus and E. multilocularis in domestic dogs and monitor the echinococcosis transmission dynamics.

METHODS

Study villages were selected using landscape patterns (Geographic Information System, GIS) for Echinococcus transmission "hot spots", combined with hospital records identifying risk areas for AE and CE. A survey of 750 domestic dogs, including copro-sampling and owner questionnaires, from 25 selected villages, was undertaken in 2012. A copro-multiplex PCR assay was used for the specific diagnosis of E. granulosus and E. multilocularis in the dogs. Data analysis, using IBM SPSS Statistics, was undertaken, to compare the prevalence of the two Echinococcus spp. in dogs between four geographical areas of Xiji by the χ2 test. Univariate analysis of the combinations of outcomes from the questionnaire and copro-PCR assay data was carried out to determine the significant risk factors for dog infection.

RESULTS

The highest de-worming rate of 84.0% was found in the northwest area of Xiji County, and significant differences (P <  0.05) in the de-worming rates among dogs from the four geographical areas of Xiji were detected. The highest prevalence (19.7%, 59/300) of E. multilocularis occurred in northwest Xiji, though the highest prevalence (18.1%, 38/210) of E. granulosus occurred in southwest Xiji. There was no significant difference (P >  0.05) in the prevalence of E. granulosus in dogs from the northwest, southwest, northeast, and southeast of Xiji, but there were significant differences (P <  0.05) between dogs infected with E. multilocularis from the four areas. None of the other independent variables was statistically significant.

CONCLUSIONS

The results from this study indicate a high prevalence of both E. granulosus and E. muiltilocularis in dogs in Xiji County, NHAR. Transmission of E. multilocularis was more impacted by geographical risk-factors in Xiji County than that of E. granulosus. Dogs have the potential to maintain the transmission of both species of Echinococcus within local Xiji communities, and the current praziquantel dosing of dogs appears to be ineffective or poorly implemented in this area.

Toxic effects of arsenic trioxide on Echinococcus granulosus protoscoleces through ROS production, and Ca2+-ER stress-dependent apoptosis

Cystic echinococcosis is a severe parasitic disease that commonly affects the liver and causes abscesses or rupture into the surrounding tissues, leading to multiple complications, such as shock, severe abdominal pain, and post-treatment abscess recurrence. Currently, there are no efficient measures to prevent these complications. We previously confirmed that arsenic trioxide (As2O3) exhibited in vitro cytotoxicity against Echinococcus granulosus protoscoleces. In the present study, we aimed to explore the mechanism of As2O3-induced E. granulosus protoscoleces apoptosis. After exposing E. granulosus protoscoleces to 0, 4, 6, and 8 μM As2O3, reactive oxygen species (ROS) level was detected by fluorescence microscopy; superoxide dismutase (SOD), and caspase-3 activities were measured; intracellular Ca2+ was detected by flow cytometry; GRP-78 and caspase-12 protein levels were measured by western blot analysis. Our results showed that the expression of caspase-3 was gradually increased and the expression of SOD was gradually decreased in As2O3-treated groups of protoscoleces. Simultaneously, fluorescence microscopy and flow cytometry showed that the ROS level and the intracellular Ca2+ level were increased in a time- and dose-dependent manner. Western blot analysis showed that the expressions of GRP-78 and caspase-12 were higher in As2O3-treated groups than in the control group. These results suggest that As2O3-induced apoptosis in E. granulosus protoscoleces is related to elevation of ROS level, disruption of intracellular Ca2+ homeostasis, and endoplasmic reticulum stress. These mechanisms can be targeted in the future by safer and more effective drugs to prevent recurrence of cystic echinococcosis.

Efficacy of ursolic acid against Echinococcus granulosus in vitro and in a murine infection model

BACKGROUND

Cystic echinococcosis is a global public health problem; however, the drugs (albendazole and mebendazole) currently recommended by WHO for its treatment, have limited efficacy. Therefore, novel drugs are required to provide more choices for the treatment of this disease.

METHODS

The anthelmintic effects of ursolic acid (UA) were tested on Echinococcus granulosus protoscoleces, germinal cells and metacestodes in vitro. The in vivo efficacy of UA was investigated in mice following secondary infection with E. granulosus. Furthermore, the corresponding ultrastructural damage induced by UA was evaluated by electron microscopy.

RESULTS

In vitro, 45.95 ± 5.30% of protoscoleces were killed by UA at 40 μg/ml, while the growth of more than 90% of germinal cells was inhibited by UA at 10 to 40 μg/ml. The same effect was observed in metacestodes 7 days after treatment with UA at 10, 20 and 40 μg/ml, and more than 50% of metacestodes showed loss of integrity at the end of the experiment. In vivo, metacestode weight was significantly reduced following oral administration of UA at 200 and 100 mg/kg (39.5 and 38.3%, respectively). Additionally, ultrastructural damage, such as alternations in germinal cell morphology and formation of vacuoles and lipid granules were observed in parasites treated with UA in vitro, while detachment of the germinal layer from the laminated layer was also seen in metacestodes in vivo.

CONCLUSIONS

UA was demonstrated to exert parasiticidal activity against E. granulosus in vitro and in vivo, thus implicating UA as a potential anti-echinococcosis agent.

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.

Anthelminthic activity of glibenclamide on secondary cystic echinococcosis in mice

Cystic echinococcosis (CE) is a worldwide parasitic zoonosis caused by the larval stage of Echinococcus granulosus. Current chemotherapy against this disease is based on the administration of benzimidazoles (BZMs). However, BZM treatment has a low cure rate and causes several side effects. Therefore, new treatment options are needed. The antidiabetic drug glibenclamide (Glb) is a second-generation sulfonylurea receptor inhibitor that has been shown to be active against protozoan parasites. Hence, we assessed the in vitro and in vivo pharmacological effects of Glb against the larval stage of E. granulosus. The in vitro activity was concentration dependent on both protoscoleces and metacestodes. Moreover, Glb combined with the minimum effective concentration of albendazole sulfoxide (ABZSO) was demonstrated to have a greater effect on metacestodes in comparison with each drug alone. Likewise, there was a reduction in the cyst weight after oral administration of Glb to infected mice (5 mg/kg of body weight administered daily for a period of 8 weeks). However, in contrast to in vitro assays, no differences in effectiveness were found between Glb + albendazole (ABZ) combined treatment and Glb monotherapy. Our results also revealed mitochondrial membrane depolarization and an increase in intracellular Ca²⁺ levels in Glb-treated protoscoleces. In addition, the intracystic drug accumulation and our bioinformatic analysis using the available E. granulosus genome suggest the presence of genes encoding sulfonylurea transporters in the parasite. Our data clearly demonstrated an anti-echinococcal effect of Glb on E. granulosus larval stage. Further studies are needed in order to thoroughly investigate the mechanism involved in the therapeutic response of the parasite to this sulfonylurea.

In this work we demonstrated the in vitro and in vivo efficacy of Glb against the larval stage of Echinococcus granulosus. At the cellular level, the drug triggered mitochondrial membrane depolarization and increased intracellular Ca²⁺ levels, thus affecting ATP generation in the parasite. In addition, since intracystic Glb concentrations were higher than those used in the external medium, we proposed that the drug might enter the cyst through cell surface transporters. The observed effect of the drug on the growth of hydatid cysts in mice leads to the consideration of a novel role of Glb in CE treatment. Therefore, our further studies will focus on the evaluation of ABZ formulations with enhanced bioavailability to achieve an improved in vivo anti-echinococcal effect using both drugs simultaneously.

Effects of trigonelline inhibition of the Nrf2 transcription factor in vitro on Echinococcus granulosus

The aim of this study was to investigate the impact of trigonelline (TRG) on Echinococcus granulosus, and to explore the inhibition impact of nuclear factor erythroid-2-related factor 2 (Nrf2) signaling pathway on E. granulosus protoscoleces. Echinococcus granulosus protoscoleces were incubated with various concentrations of TRG, and then Nrf2 protein expression and its localization in protoscoleces were detected by western blot analysis and immunofluorescence assay, respectively. Reactive oxygen species (ROS) level in protoscoleces was measured using ROS detection kit. Caspase-3 activity was measured using a caspase-3 activity assay kit, and NAD(P)H quinone oxidoreductase (NQO)-1 and heme oxygenase (HO)-1 activities in protoscoleces were measured by ELISA. The effect of TRG on protoscoleces viability was investigated using 0.1% eosin staining, and ultrastructural alterations in protoscoleces were examined by scanning electron microscopy (SEM). Immunolocalization experiment clearly showed that Nrf2 protein was predominantly present in cells of protoscoleces. TRG treatment reduced NQO-1 and HO-1 activities in protoscoleces, but could increase ROS level at early time. Protoscoleces could not survive when treated with 250 μM TRG for 12 days. SEM results showed that TRG-treated protoscoleces presented damage in the protoscoleces region, including hook deformation, lesions, and digitiform protuberance. Nrf2 protein expression was significantly decreased and caspase-3 activity was clearly increased in protoscoleces treated with TRG for 24 and 48 h, respectively, when compared with that in controls (P < 0.05). Our results demonstrated that TRG had scolicidal activity against E. granulosus protoscoleces. Nrf2 protein was mainly expressed in the cells and TRG could efficiently inhibit the Nrf2 signaling pathway in E. granulosus.

Metformin exhibits preventive and therapeutic efficacy against experimental cystic echinococcosis

Metformin (Met) is an anti-hyperglycemic and potential anti-cancer agent which may exert its anti-proliferative effects via the induction of energetic stress. In this study we investigated the in vitro and in vivo efficacy of Met against the larval stage of Echinococcus granulosus. Metformin showed significant dose- and time-dependent killing effects on in vitro cultured protoscoleces and metacestodes. Notably, the combination of Met together with the minimum effective concentration of ABZSO had a synergistic effect after days 3 and 12 on metacestodes and protoscoleces, respectively. Oral administration of Met (50 mg/kg/day) in E. granulosus-infected mice was highly effective in reducing the weight and number of parasite cysts, yet its combination with the lowest recommended dose of ABZ (5 mg/kg/day) was even more effective. Coincidentally, intracystic Met accumulation was higher in animals treated with both drugs compared to those administered Met alone. Furthermore, the safe plant-derived drug Met exhibited remarkable chemopreventive properties against secondary hydatidosis in mice. In conclusion, based on our experimental data, Met emerges as a promising anti-echinococcal drug as it has proven to efficiently inhibit the development and growth of the E. granulosus larval stage and its combination with ABZ may improve the current anti-parasitic therapy.

In vivo evaluation of the efficacy of combined albedazole-IFN-α treatment for cystic echinococcosis in mice

Cystic echinococcosis (CE) is a serious helminthic zoonosis caused by Echinococcus granulosus metacestode worldwide. The current chemotherapy of CE is mainly based on albendazole (ABZ). However, more than 20% CE cases failed to such chemotherapy. Thus, novel and more efficient treatment options are urgently needed. This study was to evaluate the in vivo efficacy of combined ABZ-interferon (IFN)-α treatment for CE in mice. After 5 months of secondary infection with protoscoleces, mice were randomly allocated into four groups: ABZ-treated group, IFN-α-treated group, ABZ+IFN-α group, and untreated control group. Drugs in diverse treated groups were respectively administered for 2 months. Mice were then euthanized and associated indications were investigated to evaluate the therapeutic efficacy. ABZ+IFN-α induced a significant reduction of the number, size, as well as weight of cysts, compared with that in the ABZ (p < 0.05) or untreated group (p < 0.01), respectively. This effect was associated with ultrastructural modification of the cyst in the ABZ+IFN-α group. Interestingly, significant decrease of IL (interleukin)-10 in serum and in vitro production by spleen cells with ABZ+IFN-α treatment was observed in comparison with untreated control (p < 0.01). Serum IgE, IgG, and subsets were respectively decreased in ABZ+IFN-α treatment, compared with that in the control group (p < 0.01). In conclusion, our findings demonstrated that combination of ABZ with IFN-α may contribute to an efficient therapeutic regimen of human and animal CE.

Intra-cystic concentrations of albendazole-sulphoxide in human cystic echinococcosis: a systematic review and analysis of individual patient data

Cystic echinococcosis (CE) is a widespread zoonosis caused by the species complex Echinococcus granulosus. Albendazole (ABZ)-the first-line anthelminthic drug for medical treatment of CE-is metabolized in vivo to the active derivative ABZ-sulphoxide (ABZ-SO). Target-site ABZ-SO concentrations in the hydatid cyst mediate the anthelminthic effect in CE. Primary outcome of this systematic review of individual patient data was the intra-cystic ABZ-SO concentration stratified by cyst size, location, calcification status and use of praziquantel. Studies reporting intra-cystic ABZ-SO concentrations in humans were identified by a systematic search. A pooled analysis of individual patient data was performed to assess intra-cystic concentrations. Pharmacokinetic data of 121 individual cysts were analysed. There was no correlation between plasma and intra-cystic ABZ-SO concentrations (rho = -0.03, p = 0.76). Intra-cystic drug concentrations were also not associated with sex and treatment duration. Use of praziquantel in combination with ABZ was associated with higher plasma (median 540 vs. 240 μg/L; p = 0.04) but not intra-cystic ABZ-SO concentrations (median 220 vs. 199 μg/L; p = 0.36). Relative drug concentrations in hepatic cysts were higher than in other cysts (0.8 vs. 0.4; p = 0.05). Intra-cystic concentrations were higher in calcified than non-calcified cysts (median 897 vs. 245 μg/L; p = 0.03). There was a trend towards higher intra-cystic concentrations in smaller sized cysts (β = -17.2 μg/L/cm; 95th CI, -35.9 to 1.6; p = 0.07). This study demonstrates that mean intra-cystic drug concentrations are similar to plasma concentrations on a population level. However, in individual patients plasma concentrations are not directly predictive for intra-cystic concentrations. The use of booster drugs was not associated with higher intra-cystic ABZ-SO concentrations in this analysis.

In Vitro Scolicidal Effects of Salvadora persica Root Extract against Protoscolices of Echinococcus granulosus

It has been known that Arak, Salvadora persica, has a number of medicinal properties. We tried to investigate in vitro scolicidal effect of root extracts of this plant against protoscolices from hydatid cysts of Echinococcus granulosus. Protoscolices were aseptically collected from sheep livers containing hydatid cysts. S. persica root extract was used in 10, 30, and 50 mg/ml concentration for 10, 20, and 30 min. The viability of protoscolices was ascertained by 0.1% eosin staining. Scolicidal activity of S. persica extract at a concentration of 10 mg/ml was 36.3%, 50.3%, and 70.8% after 10, 20, and 30 min of exposure, respectively. The scolicidal effect of this extract at a concentration of 30 mg/ml was 52.9%, 86.7%, and 100% after 10, 20, and 30 min of exposure, respectively. S. persica extract at a concentration of 50 mg/ml, meanwhile, killed 81.4%, 100%, and 100% of protoscolices after 10, 20, and 30 min, respectively. Also, the cytotoxic potential of S. persica was assessed on human liver cells (HepG2) using trypan blue exclusion test. No cytotoxic effect was observed on HepG2 cell line. The present study confirmed for the first time that the ethanolic extract of S. persica has high scolicidal power in vitro. However, in vivo effect of this material remains to be studied for treatment of echinococcosis in humans and herbivorous animals.

[EFFICACY OF A NEW MEBENDAZOLE FORMULATION FOR EXPERIMENTAL ECHINOCOCCUS GRANULOSUS LARVAL INVASION IN ALBINO MICE]

The problem of echinococcosis has acquired special urgency in Russia in the last 10 years. The dramatically worse epidemiological situation of echinococcosis in the country is suggested by just frequent cases of cystic echinococcosis in the indigenous population of Moscow and its region, including children. Currently, albendazole that is less toxic than mebendazole remains the drug of choice, However, some authors note that E. granulosus larval cysts are moresusceptible to mebendazole than to albendazole. Both drugs mainly show parasitological activity and have no larvicidal effect particularly in larval alveococcosis. Analysis of the results of chemotherapy, with a group of benzimidazole carbamates for echinococcosis in 6 clinical centers from 5 European countries (Italy, Bulgaria, Romania, Greece, and Turkey) over the past 30 years showed that the evaluation of therapeutic effectiveness was overestimated; thus, 40% of all parasitic larval cysts that were considered dead became active again after, 2 years after the treatment. The original oil micronized mebendazole suspension tested by us in albino mice with late-stage larval cystic echinococcosis showed the properties of a highly effective and safe systemic larvicide that caused prompt death in the entire parasite population in the treated animals even in extreme hyperinvasion when the baseline parasite weight was greater than the host's one.

In Vitro Anti-Echinococcal and Metabolic Effects of Metformin Involve Activation of AMP-Activated Protein Kinase in Larval Stages of Echinococcus granulosus

Metformin (Met) is a biguanide anti-hyperglycemic agent, which also exerts antiproliferative effects on cancer cells. This drug inhibits the complex I of the mitochondrial electron transport chain inducing a fall in the cell energy charge and leading 5'-AMP-activated protein kinase (AMPK) activation. AMPK is a highly conserved heterotrimeric complex that coordinates metabolic and growth pathways in order to maintain energy homeostasis and cell survival, mainly under nutritional stress conditions, in a Liver Kinase B1 (LKB1)-dependent manner. This work describes for the first time, the in vitro anti-echinococcal effect of Met on Echinococcus granulosus larval stages, as well as the molecular characterization of AMPK (Eg-AMPK) in this parasite of clinical importance. The drug exerted a dose-dependent effect on the viability of both larval stages. Based on this, we proceeded with the identification of the genes encoding for the different subunits of Eg-AMPK. We cloned one gene coding for the catalytic subunit (Eg-ampkɑ) and two genes coding for the regulatory subunits (Eg-ampkβ and Eg-ampkγ), all of them constitutively transcribed in E. granulosus protoscoleces and metacestodes. Their deduced amino acid sequences show all the conserved functional domains, including key amino acids involved in catalytic activity and protein-protein interactions. In protoscoleces, the drug induced the activation of AMPK (Eg-AMPKɑ-P¹⁷⁶), possibly as a consequence of cellular energy charge depletion evidenced by assays with the fluorescent indicator JC-1. Met also led to carbohydrate starvation, it increased glucogenolysis and homolactic fermentation, and decreased transcription of intermediary metabolism genes. By in toto immunolocalization assays, we detected Eg-AMPKɑ-P¹⁷⁶ expression, both in the nucleus and the cytoplasm of cells as in the larval tegument, the posterior bladder and the calcareous corpuscles of control and Met-treated protoscoleces. Interestingly, expression of Eg-AMPKɑ was observed in the developmental structures during the de-differentiation process from protoscoleces to microcysts. Therefore, the Eg-AMPK expression during the asexual development of E. granulosus, as well as the in vitro synergic therapeutic effects observed in presence of Met plus albendazole sulfoxide (ABZSO), suggest the importance of carrying out chemoprophylactic and clinical efficacy studies combining Met with conventional anti-echinococcal agents to test the potential use of this drug in hydatidosis therapy.

Independent evaluation of a canine Echinococcosis Control Programme in Hobukesar County, Xinjiang, China

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Xinjiang is one of the most important foci of human cystic echinococcosis in the world.

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A control programme, including PZQ dosing of dogs, began in Xinjiang in 2010.

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The control programme was evaluated using LQAS sampling, dog necropsies and questionnaires.

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The control programme did not meet our evaluation criteria in most communities studied.

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Other measures should be considered to improve Echinococcus spp. control in Xinjiang.

The Xinjiang Uyghur Autonomous Region in northwest China is one of the world's most important foci for cystic echinococcosis. Domestic dogs are the main source for human infection, and previous studies in Xinjiang have found a canine Echinococcus spp. coproELISA prevalence of between 36% and 41%. In 2010 the Chinese National Echinococcosis Control Programme was implemented in Xinjiang, and includes regular dosing of domestic dogs with praziquantel. Six communities in Hobukesar County, northwest Xinjiang were assessed in relation to the impact of this control programme through dog necropsies, dog Echinococcus spp. coproantigen surveys based on Lot Quality Assurance Sampling (LQAS) and dog owner questionnaires. We found that 42.1% of necropsied dogs were infected with Echinococcus granulosus, and coproELISA prevalences were between 15% and 70% in the communities. Although approximately half of all dog owners reported dosing their dogs within the 12 months prior to sampling, coproELISA prevalence remained high. Regular praziquantel dosing of owned dogs in remote and semi-nomadic communities such as those in Hobukesar County is logistically very difficult and additional measures should be considered to reduce canine echinococcosis.

In vitro effect of 5-fluorouracil and paclitaxel on Echinococcus granulosus larvae and cells

Human cystic echinococcosis is a zoonosis caused by the metacestode stage of the tapeworm Echinococcus granulosus. Although benzimidazole compounds such as albendazole and mebendazole have been the cornerstone of chemotherapy for the disease, there is often no complete recovery after treatment. Hence, in searching for novel treatment options, we examined the in vitro efficacies of 5-fluorouracil (5-FU) and paclitaxel (PTX) against E. granulosus germinal cells, protoscoleces and cysts. 5-FU or PTX inhibited the growth of E. granulosus cells in a time dependent manner. Although both treatments had a protoscolicidal effect, 5-FU had a considerably stronger effect than PTX. 5-FU produced a dose- and time-dependent effect, provoking the complete loss of viability after 24 days of incubation. Moreover, cysts did not develop following the inoculation of treated protoscoleces into mice. The loss of viability was slower in PTX treated protoscoleces, reaching to approximately 60% after 30 days. The results of the in vitro treatment with 5-FU and PTX were similar in secondary murine cysts. The employment of SEM and TEM allowed us to examine, at an ultrastructural level, the effects induced by 5-FU and PTX on E. granulosus germinal cells, protoscoleces and murine cysts. In conclusion, the data obtained clearly demonstrated that 5-FU and PTX at clinically achievable concentrations inhibit the survival of larval cells, protoscoleces and metacestodes. In vivo studies to test the antiparasitic activities of 5-FU and PTX are currently being undertaken on the murine model of cystic echinococcosis.

[Efficacy of albendazole chitosan microspheres against Echinococcus granulosus infection in mice]

OBJECTIVE

To observe the therapeutic effect of albendazole chitosan microspheres (ABZ-CS-MPs) on cystic echinococcosis in mice.

METHODS

Two hundred male kunming mice were each infected by intraperitoneal inoculation of about 5 000 viable protoscoleces of Echinococcus granulosus. Another 20 mice were kept as blank control. After 12 weeks post infection, the mice were randomly divided into four groups named as infection control group (n = 20), ABZ-CS-MPs group, albendazole liposome (L-ABZ) group, and albendazole tablet group. The latter three treatment groups were then each divided into three subgroups (n = 20) by given the dose of 37.5, 75.0, and 150.0 mg/kg for three times per week, respectively. After 12 weeks of treatment, all mice were sacrificed. The weight of hydatid cysts was measured and the inhibition rate were calculated. Mouse liver was observed. The histopathological changes of E. granulosus were observed by microscopy. The concentration of albendazole sulfoxide in plasma and liver tissues was determined by high-performance liquid chromatography.

RESULTS

Compared with the other treatment groups, the turbidity of contained fluid, the consolidation level and calcification level of hydatid cysts in ABZ-CS-MPs group were higher. The average weight of hydatid cysts in each treatment group was lower than that of infection control group [(3.19 +/- 2.94) g] (P < 0.05). The cyst weight in 37.5, 75.0, and 150.0 mg/kg ABZ-CS-MPs group [(0.28 +/- 0.28), (0.24 +/- 0.22), and (0.20 +/- 0.19) g, respectively] was lower than that of albendazole tablet groups [(0.77 +/- 0.74), (0.55 +/- 0.42), (0.76 +/- 0.35) g] (P < 0.05). Among the same dosage groups, the inhibition rate in ABZ-CS-MPs group (from low to high dosage sub-group: 91.1%, 92.6%, and 93.7%, respectively) was highest. In 75.0 mg/kg ABZ-CS-MPs group, there were 15 mice with class I (degeneration) and II (necrosis) pathological changes of E. granulosus hydatid. The number of mice with class I and II pathological changes in each dosage ABZ-CS-MPs sub-group and L-ABZ sub-group was more than that of albendazole tablet group (P<0.05). Plasma concentration of albendazole sulfoxide in 75.0 and 150.0 mg/kg ABZ-CS-MPs sub-groups [(0.83 +/- 0.39), (0.80 +/- 0.5) microg/ml] were higher than that of L-ABZ sub-groups [(0.34 +/- 0.03), (0.43 +/- 0.15) microg/ml] and albendazole tablet sub-groups [(0.31 +/- 0.02), (0.40 +/- 0.10) microg/ml] (P < 0.05). Compared with 37.5, 75.0, and 150.0 mg/kg albendazole tablet sub-groups [(0.04 +/- 0.02), (0.07 +/- 0.04), (0.04 +/- 0.0) microg/g], the albendazole sulfoxide concentration in liver tissue was higher in ABZ-CS-MPs sub-groups [(0.33 +/- 0.06), (0.45 +/- 0.31), (0.50 +/- 0.30) microg/g] (P < 0.05). In 37.5 mg/kg dosage sub-group, the albendazole sulfoxide concentration in liver tissue in ABZ-CS-MPs group was higher than that of L-ABZ group [(0.14 +/- 0.19) microg/g] (P < 0.05).

CONCLUSION

ABZ-CS-MPs can reduce the weight of hydatid cyst and increase the concentration of al-bendazole sulfoxide in plasma and liver tissue of mice.

[Efficacy of nocodazole et experimental invasion Echinococcus granulosus of white mice]

The therapeutic activity of subcutaneous and intraperitoneal nocodazole injections was studied in albino mice with experimental E. granulosus invasion. The animals were intraperitoneally infected with Echinococcus larval cysts (ELC) from a spontaneously inoculated sheep. Nocodazole aqueous suspension (NAS) was administered at the late stage of invasion in two experiments. In one experiment, the treatment was initiated 7.5 months after inoculation. The animals were given daily subcutaneous injections of gradually increasing daily doses (n = 32) from 5 to 20 mg/kg twice weekly for 4 months (the total active ingredient dose was 400 mg/kg). The mice were dissected 3 months after treatment termination. Their autopsy showed that all ELCs or their vast majority were dead in 17 (70.8%) of 24 NAS-treated mice. Among the completely cured mice, there were animals having dead ELCs amounting to 36.9% of the host's weight. In the other experiment, the mice received intraperitoneal treatment 11.5 months after inoculation. They were given NAS injections (n = 2-8) in the total active ingredient dose of 14-126 mg/kg for 4-32 days. The animals were dissected 12-14 months after inoculation. All the detected ELCs were ascertained to be dead in the mice that had received NAS in an active ingredient dose of 87-126 mg/kg and had been dissected 33-81 days after initiation of treatment. The damaging effect of NAS was accompanied by obvious ELC collapse (the ELC collapse index was 57.5-75.9% for all the cured animals).

[Enhancement of in vitro protoscolicidal effects of high-intensity focused ultrasound by a superabsorbent polymer and ultrasound contrast agent]

This study evaluated whether or not a superabsorbent polymer (SAP) combined with ultrasound contrast agent (UCA) could enhance damage efficacy of high intensity focused ultrasound (HIFU) on Echinococcus granulosus protoscoleces in vitro. Thirty test tubes each with 6 000-7 500 protoscolices were divided into 5 groups: group A (blank control) without HIFU treatment, group B treated with HIFU (50 W) only, group C treated with 10 microl UCA and HIFU, group D treated with 0.01 g SAP and HIFU, group E treated with 10 microl UCA, 0.01 g SAP, and HIFU. In group B, echo enhancement of ultrasound image, suspension temperature (26.0 degrees C +/- 0.2 degrees C) and protoscoleces mortality (30.4%) were higher than that of group A (18.0 degrees C +/- 0.1 degrees C, 1.9%) (P < 0.01). Compared with group B, the echo enhancement of ultrasound image, suspension temperature (27.0 degrees C +/- 0.2 degrees C, 28.2 degrees C +/- 0.2 degrees C) and protoscoleces mortality (50.0%, 53.7%) of groups C and D increased significantly (P < 0.01). In group E, more protoscoleces were stained in red and their internal structures were indistinct. By chi-square test, the protoscoleces mortality of group E (69.7%) was higher than that of groups C and D (P < 0.01). There was no significant difference in suspension temperature among the 3 groups.

A case of cardiac hydatidosis: role for transesophageal echocardiography in evaluating bilateral pulmonary nodules

Echinococcusis is a zoonotic disease, which is endemic in sheep-raising areas such as Iran. Cardiac involvement of the hydatidosis is rare and mostly asymptomatic, but it could lead to lethal complications. Thus, early diagnosis with accurate treatment would be life-saving. Here we report a 17-year-old female with nonspecific pulmonary presentations and a positive history of pulmonary hydatid cysts. Transesophageal echocardiography showed multiple cardiac hydatid cysts in the right ventricle. Patient underwent the bypass surgery to remove cardiac cysts. Postoperatively patient was on Albendazole and Praziquantel for two years. In a two-year-follow up, the patient had no complications.

[In vitro metabolism of fenbendazole prodrug]

Synthesized fenbendazole prodrug N-methoxycarbonyl-N'-(2-nitro-4-phenylthiophenyl) thiourea (MPT) was analyzed in vitro in artificial gastric juice, intestinal juice and mouse liver homogenate model by using HPLC method, and metabolic curve was then generated. MPT was tested against Echinococcus granulosus protoscolices in vitro. The result showed that MPT could be metabolized in the three biological media, and to the active compound fenbendazole in liver homogenate, with a metabolic rate of 7.92%. Besides, the prodrug showed a weak activity against E. granulosus protoscolices with a mortality of 45.9%.

Hydatid lung disease: an analysis of five years cumulative data from Kolkata

BACKGROUND AND OBJECTIVE

There is scarcity of clinical data regarding hydatid lung disease from Indian subcontinent. In this retrospective study we analyzed the cumulative data over five year's period from two tertiary care hospitals of Kolkata to determine the presentation, treatment and outcome of hydatid disease of lung.

METHOD

We analyzed 106 patients on the basis of clinical findings, radiological findings [chest X-ray--PA and lateral view, CT scan of thorax and upper abdomen, ultrasonography (USG) of thorax and upper abdomen] and serological test IgG ELISA (enzyme linked immunosorbent assay) against echinococcus granulosus antigen along with the mode of diagnosis, indications and types of surgery, and outcome of treatment with chemotherapy (albendazole), surgery and combined surgery with chemotherapy.

RESULT

There was female preponderance with median age of presentation 33 years with interquartile range of 7. At the time of diagnosis 14.15% patients were asymptomatic. Cough was the commonest symptom (73.58%) followed by chest pain (54.72%). Single sharply demarcated round or oval homogenous opacity was the commonest radiological sign (81.13%). Complicated cysts such as lung abscess, pleural involvement, pneumonitis and fibrosis were noted in 10.38%, 13.21%, 7.55% and 11.32% cases respectively. We found that serological test was only 77.01% sensitive. Eighty-two (86.32%) patients underwent surgery, and 56.10% of them received additional chemotherapy with albendazole. The types of operation performed were pericystectomy (in 91.46% cases), lobectomy (in 6.10% cases) and pneumonectomy (in 2.44% cases). Perioperative mortality was nil but morbidity was found in 10.98% cases with empyema (8.54%), the commonest complication. Thirteen inoperable patients were treated with albendazole, among them 8 showed reduction of cyst-size, 3 showed no change and 2 patients showed obliteration of cyst.

CONCLUSION

Surgery is a safe and effective way of treatment for thoracic hydatid cyst along with perioperative albendazole therapy. There is a scope for chemotherapy with albendazole in inoperable cases.

Identification of thioredoxin glutathione reductase inhibitors that kill cestode and trematode parasites

Parasitic flatworms are responsible for serious infectious diseases that affect humans as well as livestock animals in vast regions of the world. Yet, the drug armamentarium available for treatment of these infections is limited: praziquantel is the single drug currently available for 200 million people infected with Schistosoma spp. and there is justified concern about emergence of drug resistance. Thioredoxin glutathione reductase (TGR) is an essential core enzyme for redox homeostasis in flatworm parasites. In this work, we searched for flatworm TGR inhibitors testing compounds belonging to various families known to inhibit thioredoxin reductase or TGR and also additional electrophilic compounds. Several furoxans and one thiadiazole potently inhibited TGRs from both classes of parasitic flatworms: cestoda (tapeworms) and trematoda (flukes), while several benzofuroxans and a quinoxaline moderately inhibited TGRs. Remarkably, five active compounds from diverse families possessed a phenylsulfonyl group, strongly suggesting that this moiety is a new pharmacophore. The most active inhibitors were further characterized and displayed slow and nearly irreversible binding to TGR. These compounds efficiently killed Echinococcus granulosus larval worms and Fasciola hepatica newly excysted juveniles in vitro at a 20 µM concentration. Our results support the concept that the redox metabolism of flatworm parasites is precarious and particularly susceptible to destabilization, show that furoxans can be used to target both flukes and tapeworms, and identified phenylsulfonyl as a new drug-hit moiety for both classes of flatworm parasites.

Albendazole associated to surgery or minimally invasive procedures for hydatid disease--how much and how long

Cystic echinococcosis is parasitic disease due to the larval stage of the metacestode Echinococcus granulosus in the liver (80%), lungs, kidneys, spleen, myocardium etc. Humans are accidental intermediate hosts. Diagnosis is based on laboratory and imaging studies. Treatment is multimodal, surgical and medical. Risks for dangerous complications and relapses are quite common. Adequate follow-up is needed. Albendazole has a central role in the medical therapy of the disease.

In vitro lethal effect of ajowan (Trachyspermum ammi L.) essential oil on hydatid cyst protoscoleces

Various chemical scolicidal agents have been used for inactivation of hydatid cyst protoscolices, but most of them are associated with adverse side effects. Since ajowan (Trachyspermum ammi) has been shown to have a number of medicinal properties, in this study the scolicidal effect of the essential oil (EO) from the fruits of this herbal plant was investigated. Ajowan EO was obtained by hydrodistillation method. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the chemical composition of the EO. Protoscoleces were exposed to various concentrations of EO (3, 5 and 10mg/mL) for 10, 20, 30, and 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining. A total of 18 compounds representing 99.54% of the total oil, were identified. Thymol (50.07%), γ-terpinene (23.92%), and p-cymene (22.9%) were found to be the major EO constituents. While the mortality rate of protoscolices in the control group was 6.67%, scolicidal power of ajowan EO at concentration of 3mg/mL was 31.34, 35.98, 45.17, and 51.58% after 10, 20, 30, and 60 min, respectively. The EO at concentration of 5mg/mL killed 51.89, 72.20, 88.64, and 100% of protoscolices after 10, 20, 30, and 60 min, respectively. One hundred percent scolicidal activity was observed with ajowan EO at concentration of 10mg/mL after 10 min of exposure. The results of this study revealed that the EO of ajowan is rich in thymol, γ-terpinene and p-cymene, has high scolicidal power and it may be used as a natural scolicidal agent.

[The protoskolicidal effect of 1% polyvinylpyrrolidone-iodine (PVP-1) and 2% taurolidine on abdominal hydatidosis]

The aim of this study is to determine the efficacy of 1% polyvinylprolidone-iodine (Betadine, PVP-I) and 2% Taurolidine as scolicidal agents for the prevention of abdominal hydatidosis defined as the rupture of the echinococcal cyst spontaneously or traumatically. The study was carried out in fifty mice randomly assigned into 5 treatment groups as following: group with no expose to any scolicidal agent, groups with 1% PVP-I for 2 and 5 minutes; groups with 2 % Taurolidine for 2 minutes, and 5 minutes. PVP-I has found to be effective according to results of staining with the eosin dye in vitro and abdominal hydatidosis in vivo, while Taurolidine was ineffective as a scolicidal agent.

[Apoptosis induced in vitro by dexamethasone and ATP in the protoscolex of Echinococcus granulosus]

OBJECTIVE

To explore the apoptosis induced by dexamethasone and adenosine triphosphate (ATP) in protoscolex of Echinococcus granulosus.

METHODS

Protoscoleces were cultured in vitro and used for the experiment in 4 groups: dexamethasone (5 mmol/L) group, ATP (1.6 mmol/L) group, dexamethasone (5 mmol/L)+ATP (1.6 mmol/L) group, and RPMI 1640 medium as control group. The morphology of protoscolex was observed by light microscopy. After drug treatment for 8 h, the group with significant morphological changes in protoscolex was selected to observe the ultrastructure of protoscolex by transmission electron microscopy. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay (TUNEL) was employed to observe the apoptosis. Caspase-3 activity was detected with a kit, and DNA fragments were seperated by agarose gel electrophoresis.

RESULTS

After induced for 8 h, the protoscoleces shrank in dexamethasone group and dexamethasone+ATP group, the rostellum was invaginated. Compared with the control, the calcareous corpuscles in the protoscolex significantly reduced and blurred in the two groups The morphological changes in protoscolex of dexamethasone+ATP group was more obvious than that of dexamethasone group. Electron microscopy showed that dexamethasone+ATP-treated protoscoleces possessed typical morphological features of apoptosis, including the cell volume reduction with densified cytoplasm, cell membrane blebbing, and nuclear heterochromatin peripheral aggregation below the nuclear membrane. A few apoptotic cells were found in protoscolex of dexamethasone+ATP group by TUNEL, while none in the control. Caspase-3 activity significantly increased 12-fold compared to the control. About 150 bp DNA fragment exhibited the typical DNA ladder formation characteristic for apoptosis in dexamethasone+ATP group.

CONCLUSION

Apoptosis in the protoscolex of E. granulosus may be induced by dexamethasone and ATP in vitro.

[Effect of liposomal albendazole on the ultrastructure of Echinococcus granulosus cysts in mice]

AIM

To observe the histopathological changes of Echinococcus granulosus cysts in mice treated with liposomal albendazole and co-administration with cimetidine by light microscopy and electron microscopy.

METHODS

An oral dose of liposomal ABZ with different formulations was given at 200 mg/kg.d. Cimetidine was administered daily at an oral dose of 100 mg/kg.d. Sixty-seven mice were orally given different drugs six days per week for a total of twelve weeks.

RESULTS

The histopathological changes indicated that there were significant differences (P < 0.01) between treated groups and control group. The degeneration and necrosis of E. granulosus cysts were marked in liposomal albendazole combined with cimetidin group.

CONCLUSION

Liposomal albendazole was more effective against E. granulosus cyst than albendazole. Cimetidine had an apparent synergistic effect when given in combination with liposomal albendazle.

Case report: nitazoxanide for treatment of refractory bony hydatid disease

Although nitazoxanide has been shown to have activity against Echinococcus multilocularis in animal studies and against E. granulosus in vitro, its use in treatment of human cystic echinococcosis has not been reported. We report a case of progressive bony hydatid disease treated with nitazoxanide that showed a clinical and radiologic response. The patient had a 40-year history of hydatid disease involving the left hip. Despite prolonged courses of albendazole and praziquantel, she had progressive disease with extensive involvement of the left hemipelvis and adjacent soft tissue cysts. She was treated with nitazoxanide, 500 mg twice a day for 3 months in combination with albendazole. The clinical response was supported by imaging showing marked improvement in the soft tissue cysts, with stable disease in the bony pelvis. Although further studies are required, this case suggests that nitazoxanide may be an effective treatment option in hydatid disease, particularly in patients with progressive disease who are receiving conventional therapy.

Anthelminthic treatment: an adjuvant therapeutic strategy against Echinococcus granulosus

The main goal of the paper is to clarify anthelminthic treatment as an alternative hydatic cyst therapy, its indications and contraindications. Chemotherapy constitutes a non-invasive treatment and is less limited by the patient's status than surgery or PAIR. Many investigators have employed benzoimidazole carbonates for the management of human hydatid disease. Both, albendazole and mebendazole have, a favourable effect in patients suffering from multiorgan and multicystic disease, in inoperable primary liver or lung echinococcosis, and they can also prevent secondary echinococcosis. Chemotherapy is contraindicated for large cysts that are at risk to rupture and for inactive or calcified cysts. The main adverse events are related to changes in liver enzyme levels. The best efficacy is observed with liver, lung, and peritoneal cysts. Certain various factors influence the therapeutic results of medical treatment. The vast majority of the recurring cysts show good susceptibility to re-treatment.

[In vitro observation on albendazole sulfoxide and its enantiomers against Echinococcus granulosus protoscolex]

OBJECTIVE

To investigate in vitro anti-hydatid efficacy on Echinococcus granulosus protoscolex (EgPSC) by using albendazole sulfoxide (ASOX) and its two enantiomeric antipodes, L-ASOX and D-ASOX.

METHODS

Eg protoscoleces were divided into eight groups and cultured in the DMEM culture media under two concentrations(50 microg/ml and 100 microg/ml) of ASOX, L-ASOX and D-ASOX respectively. The appropriate controls included (i) a culture containing an equal amount of DMSO and (ii) a culture medium alone. The mortality of EgPSC in each group was daily counted until 100% EgPSC death in some groups.

RESULTS

Significant difference of EgPSC mortality was found among the three drugs with various concentrations compared to control group (P < 0.01), and a significant difference between L-ASOX group and D-ASOX group (P < 0.05). There were no statistical difference between ASOX group and D-ASOX group (P > 0.05), but between ASOX group and L-ASOX group (P < 0.05). On the 9th day of culture, the mortality of protoscoleces with the concentration of 50 microg/ml was 93.6%, 56.2% and 99.0% in ASOX, L-ASOX and D-ASOX groups respectively, and those under the concentration of 100 microg/ml were 100%, 74.5% and 100% respectively. The mortality was 19.1% and 22.5% respectively in the control and solvent groups.

CONCLUSION

ASOX, L-ASOX and D-ASOX demonstrate significant effect of anti- Eg protoscolex in vitro. D-ASOX shows stronger effect than L-ASOX.

[Effect of the liposome albendazole and Huai-Er fungus extract on hepatic infection of Echinococcus granulosus in mice]

OBJECTIVE

To explore the effect of Huai-Er fungus extract (HEF) and liposome albendazole (L-ABZ) on the hepatic infection of Echinococcus granulosus (Eg) in mice, and understand the influence of improved host immunity on postoperative recurrence.

METHODS

Female Kunming mice were immune by intraperitoneal injection Eg cyst fluid from sheep, IgG positive mice were divided into drug treatment groups (A, B and C) and control group (D). Mice in group A were administered by gavage with single L-ABZ (75 mg/kg), group B with single HEF (15,000 mg/kg), and group C with combination therapy (L-ABZ 75 mg/kg plus HEF 15,000 mg/kg), once every two days for one week. The protoscoleces were treated with balanced solution for 20 minute and inoculated in the liver by open abdomen of the anesthetized mice. Imitating to an "open sub-adventitial total exocystectomy", protoscoleces outside the cyst led to a reinfection. 72 hours later, groups A, B and C were re-treated for a month. Mice in group D were given with distilled water (0.3 ml per mouse). Group E was set as blank control (n=8). Another 120 IgG positive mice were divided as groups F, G, H and I, and treated in parallel with the groups A, B, C and D respectively; these mice were inoculated with protoscoleces which were treated in advance with 75% alcohol, 20% hypertonic saline, L-ABZ and PBS for 20 min respectively. In 3 months after infection, all the mice were sacrificed to evaluate the efficacy, which covered infection rate, pathological change, spleen index, level of IgG and IgE, CD4+ and CD8+ cells.

RESULTS

The recurrence rate in group C (5.7%) was lower than that of groups A (17.1%) and B (24.2%), with hydatid cysts in white colour and nodular, showing degeneration of the germinal and laminated layers. Groups A, B and C showed lower spleen index (A: 3.84+/-0.86, B: 3.95+/-1.01, and C: 3.27+/-0.52), and lower IgE level (A: 0.06+/-0.08, B: 0.07+/-0.08 and C: 0.03+/-0.03) than group D (5.46+/-0.52 and 0.20+/-0.02, respectively) (P<0.05), especially in group C; and also lowerCD8+ in groups A (16.61+/-3.89), B (18.18+/-3.90) and C (15.38+/-2.63) than group D (32.90+/-4.71) (P<0.05), but higher CD4+/CD8+ in groups A (3.21+/-0.70), B (3.05+/-0.66) and C (3.53+/-0.57) than group D (1.57+/-0.26) (P<0.05), especially in group C. The infection rate of mice in group F, Gand H was 0, 0 and 23.1% respectively, and that of group I, 31.2% (P<0.01).

CONCLUSION

The combination of HEF and L-ABZ considerably improves the immunity of the hosts and HEF may have a synergetic action to L-ABZ in reducing the recurrence of "sub-adventitial total exocystectomy". 75% alcohol and 20% hypertonic saline show better effect of inactivating protoscoleces than L-ABZ in surgical operation.

[In vitro observation on the apoptosis induced by H2O2 in protoscolex of Echinococcus granulosus]

OBJECTIVE

To explore the apoptosis induced by hydrogen peroxide (H2O2) in protoscolex of Echinococcus granulosus.

METHODS

Protoscoleces were cultured in vitro, and used for the experiment in 2 groups: RPMI 1640 medium and RPMI 1640 medium added with glutamine. They were then treated with different concentrations of H2O2 to induce apoptosis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay (TUNEL) was employed to observe the apoptosis. Protein expression of caspase-1, caspase-3 and Fas was detected by SP immunohistochemical technique, stained with DAB restained with hematoxylin. A yellow or brown color nucleus revealed positive apoptosis cells in protoscolex, a brown reaction product in cytoplasm showed positive cells of caspase-1 and caspase-3, and brown cell membrane and cytoplasm revealed Fas product; otherwise it was judged as negative. According to the percentage of positive cells in a protoscolex, the expression level was divided as 4 grades. The percentage of less than 5% was regarded as "-", 5%-25% as "+", 26%-50% as "++", more than 50% as "+++". The experiments were repeated 2 times with controls.

RESULTS

In RPMI 1640 group, positive TUNEL was found in the protoscolex induced by 1 mmol/L H2O2 inducing for 12 hours. Induced by 1 mmol/L H2O2 for 4 h, the "+-++" expression rate of caspase-1 and caspase-3 in the protoscoleces was 86.6% and 77.8%, and for 8 h, 86.6% and 80.0% respectively, a significant increase in comparison to the control (P<0.05). Induced by 5 mmol/L H2O2 for 4 hours, the "++-+++" expression rate of caspase-1 was 93.0%, and the "+-++" expression rate of caspase-3 was 89.5%; induced for 8 h, the "++-+++" expression rate of caspase-1 decreased to 53.2%, and the "+-++" expression rate of caspase-3 decreased to 48.4% and "-" expression rate increased to 46.8%. Under 5 mmol/L H2O2 for 4 h the expression rate of caspase-3 significantly decreased at 8 h (P<0.01). In the group of RPMI 1640 plus glutamine, induced by 5 mmol/L H2O2 for 8 h, the "++ -+++" expression rate of caspase-3 in protoscolex was 100% (P<0.01). However, in RPMI 1640 group, induced by 5 mmol/L H2O2 for 8 h, the "++-+++" expression rate of caspase-3 in protoscolex was 32.2% and 46.8% were negative. The Fas product with positive reaction in protoscolex was found in both control and induced groups: in RPMI 1640 group, under 5 mmol/L H2O2 induced for 4 h, "+-++" expression rate was 53.0% and control was 20.0%; and in the group of RPMI 1640 plus glutamine, under 5 mmol/L H2O2 induced for 8 h, "+-++" expression rate was 88.7% and control was 71.4%, increased in both groups after induction (P <0.05).

CONCLUSION

Apoptosis in the protoscolex of E. granulosus may be induced by H2O2.

Therapeutic effects of Sophora moorcroftiana alkaloids in combination with albendazole in mice experimentally infected with protoscolices of Echinococcus granulosus

The objective of the present study was to determine if the combination of alkaloids from Sophora moorcroftiana seeds and albendazole might be effective in the treatment of experimental echinococcosisin female NIH mice (6 weeks old and weighing 18-20 g, N = 8 in each group) infected withprotoscolices of Echinococcus granulosus. Viable protoscolices (N = 6 x 10(3)) were cultured in vitro in 1640 medium and mortality was calculated daily. To determine the in vivo efficacy, mice were inoculated intraperitoneally with viable protoscolices and then treated once daily by gavage for three months with the alkaloids (50 mg kg-1 day-1) and albendazole (50 mg kg-1 day-1), separately and in combination (both alkaloids at 25 mg kg-1 day-1 and albendazole at 25 mg kg-1 day-1). Next, the hydatid cysts collected from the peritoneal cavity of the animals were weighed and serum IL-4, IL-2, and IgE levels were analyzed. Administration of alkaloids to cultured protoscolices showed significant dose- and time-dependent killing effects. The weight of hydatid cysts was significantly decreased upon treatment with each drug (P < 0.01), but the decrease was more prominent and the rate of hydatid cyst growth inhibition was much higher (76.1%) in the group receiving the combined treatments (18.3 +/- 4.6 mg). IL-4 and total IgE were decreased (939 +/- 447 pg/mL and 2.03 +/- 0.42 IU/mL, respectively) in serum from mice treated with alkaloids and albendazole compared with the untreated control (1481 +/- 619 pg/mL and 3.31 +/- 0.37 IU/mL; P < 0.01). These results indicate that S. moorcroftiana alkaloids have protoscolicidal effects and the combination of alkaloids and albendazole has significant additive effects.

Effect of octenidine dihydrochloride on viability of protoscoleces in hepatic and pulmonary hydatid diseases

BACKGROUND

Use of effective scolicidal agents during puncture, aspiration or injection of a scolicidal agent and reaspiration (PAIR) and surgery for hydatid cysts are essential to reduce the recurrence rate. In this in vitro study, we tried to determine the scolicidal property of a new agent, octenidine dihydrochloride, and of various agents in different concentrations and exposure times.

MATERIAL AND METHODS

Echinococcus granulosus protoscoleces were obtained from six patients with liver (n=3) and lung (n=3) hydatid cysts. Various concentrations of octenidine dihydrochloride (0.1%, 0.01% and 0.001% diluted form), povidone iodine (10%, 1% and 0.1% diluted) and 20% saline were used in this study. Viability of protoscoleces was determined with dye-uptake (0.1% eosin) and flame cell activity.

RESULTS

Octenidine dihydrochloride 0.1% had strong scolicidal effect in 15 min and octenidine dihydrochloride 0.01% in 30 min. Sixty percent of protoscoleces lost viability at 5 min with octenidine dihydrochloride 0.1%. Viability ratio decreased to 20% at 10 min, and all of them died at 15 min. Povidone iodine 10% and 1% had strong scolicidal effects after 15- and 30 min of exposure, respectively. Saline 20% killed all the protoscoleces in 30-min exposure.

CONCLUSION

Because of the rapid and strong scolocidal effectiveness of octenidine dihydrochloride on protoscoleces, it may be used as a scolocidal agent during both perioperative and in the PAIR method.

Intact germinal layer of liver hydatid cysts removed after administration of albendazole

BACKGROUND

Hydatid disease is a common health problem especially in Mediterranean and sheep-farming countries, caused by infection with the metacestode stage of the tapeworm Echinococcus. The liver is the most frequent primary site of Echinococcus granulosus infection in humans. Surgery remains the main treatment modality for cystic hepatic hydatid disease, with complete resection of the germinal layer being of major importance for recurrence. Perioperative administration of albendazole has been reported to improve surgical outcome but the results are controversial. We report here our observations on the usefulness of preoperative chemotherapy in surgical outcome in terms of morbidity and recurrence.

METHODS

Five patients with complex liver hydatid cysts received 28 days of albendazole prior to partial cystectomy. Radiological examinations with computed tomography and ultrasound and surgical outcome were used to assess the efficacy of the regimen.

RESULTS

Three patients underwent a complete removal of the germinal layer of the cyst and there were no cases of biliary fistula in these patients. There were no relapses in any of the patients at 12 months' follow-up.

CONCLUSIONS

Preoperative use of medical therapy consisting of albendazole facilitates complete resection of the germinal layer by detaching it from the laminar layer, thus reducing not only the recurrence rates but also the postoperative complications, especially bilious fistulas.