Efficacy of thymol against Echinococcus granulosus protoscoleces

Evaluation of the Protoscolicidal Activity of Humulus lupulus Methanolic Extracts on Echinococcus granulosus Sensu Stricto

The larval stage of the parasite Echinococcus granulosus sensu lato (s.l) is responsible for cystic echinococcosis (CE), a long-term infection affecting humans and animals worldwide, and constitutes a serious public health concern. If left untreated, CE can cause serious damage to multiple organs, especially the liver and lungs. Regarding the treatment, in the last few years, the use of pharmacological treatment has increased, suggesting that in the future, drug therapy may replace surgery for uncomplicated cysts. However, the only available anthelmintic drug to treat this infection is the albendazole, which has an efficacy that does not exceed 50%. On the basis of the above-mentioned evidence, new and improved alternative treatments are urgently needed. The use of natural products and their active fractions and components holds great promise as a valuable resource for the development of novel and effective therapies. Hop (Humulus lupulus L.) is a bittering agent in the brewing industry for which the sedative, digestive, anti-inflammatory, and antimicrobial effects have been reported. The purpose of this study was to assess the in vitro efficacy of methanolic extracts from the leaves of hop varieties against E. granulosus sensu stricto (s.s) protoscoleces. Varieties Mapuche and Victoria caused a stronger protoscolicidal effect compared to the Bullion, Cascade, and Traful varieties (P < 0.01), coinciding with their highest content of flavonoids, total polyphenols, and saponins. The viability of protoscoleces treated with the varieties Mapuche and Victoria decreased to approximately 50% at days 5 y 8, respectively, showing alterations such as soma contraction and impaired microtriches. After 18 days of treatment with both varieties, protoscoleces were completely altered both structurally and ultrastructurally. In conclusion, the methanolic extracts of the H. lupulus varieties Mapuche and Victoria demonstrated a marked in vitro effect against E. granulosus s.s. protoscoleces. The beer-making industry exclusively uses hop cones, leaving behind large amounts of hop leaves as an agricultural by-product that is not being utilized. On the basis of our study, we propose that hop leaves could also be used as a source of secondary metabolites with anthelmintic activity.

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.

Anthelmintic Effect of Cannabidiol against Echinococcus granulosus sensu stricto

Cystic echinococcosis is a global parasitic zoonosis caused by infection with the larval stage of Echinococcus granulosus sensu lato. Cystic echinococcosis affects more than 1 million people worldwide, causing important economic costs in terms of management and livestock associated losses. Albendazole is the main drug used in treating human cystic echinococcosis. In spite of this, its low aqueous solubility, poor absorption, and consequently erratic bioavailability are the cause of its chemotherapeutic failures. Based on the described problem, new treatment alternatives urgently need to be developed. The aim of the present research was to study the in vitro and in vivo efficacy of cannabidiol (CBD), the second most abundant component of the Cannabis sativa plant, was demonstrated against E. granulosus sensu stricto. CBD (50 µg/mL) caused a decrease in protoscoleces viability of 80 % after 24 h of treatment which was consistent with the observed tegumental alterations. Detachment of the germinal layer was observed in 50 ± 10% of cysts treated with 50 µg/mL of CBD during 24 h. In the clinical efficacy study, all treatments reduced the weight of cysts recovered from mice compared with the control group. However, this reduction was only significant with ABZ suspension and the CBD + ABZ combination. As we could observe by the SEM study, the co-administration of CBD with ABZ suspension caused greater ultrastructural alteration of the germinal layer in comparison with that provoked with the monotherapy. Further in vivo research will be conducted by changing the dose and frequency of CBD and CBD + ABZ treatments and new available CBD delivery systems will also be assayed to improve bioavailability in vivo.

Evaluation of structural changes of Echinococcus granulosus protoscoleces following exposure to different protoscolicidal solutions evaluated by differential interference contrast microscopy

The present study was aimed to assess the structural changes in protoscoleces of Echinococcus granulosus sensu stricto following exposure to different natural and chemical protoscolicidal agents using differential interference contrast (DIC)/Nomarski microscopy. Protoscoleces of sheep's liver cysts were collected aseptically. Individually, about 1000 protoscoleces were exposed to 0.5% silver nitrate, 20% hypertonic saline solution, 0.5% cetrimide solution and two different concentrations of garlic chloroformic extraction as well as phosphate-buffered saline (PBS). The protoscoleces viability was assessed using 0.1% eosin solution, and structural modifications in the protoscoleces were examined by DIC/Nomarski microscopy. The results revealed the degeneration of the tegument, disorganization of the hooks, and reduction of the size of the protoscoleces exposed to cetrimide, hypertonic sodium chloride, and silver nitrate. Furthermore, calcareous corpuscles became blurred and opaque and their numbers decreased in all the exposed samples except, those in PBS. The exposed protoscoleces to cetrimide and hypertonic sodium chloride solution showed extensive degeneration of the tegument and disorganization of the hooks. In the group exposed to 200 mg/ml chloroformic garlic extract, the protoscoleces' width decreased. The length, width, and number of calcareous corpuscles also decreased significantly in the silver nitrate-exposed protoscoleces. The study concludes that protoscoleces exposed to different solutions; cetrimide 0.5% and hypertonic sodium chloride 20% caused more pronounced structural changes in the exposed protoscoleces. These changes were well demonstrated by DIC microscopy and can be used as a supplementary tool to evaluate the effects of protoscolicidal agents.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-023-01632-4.

Experimental treatment of cystic echinococcosis: Combination therapy with carvacrol and thymol versus albendazole

Cystic echinococcosis is a worldwide zoonotic disease caused by Echinococcus granulosus sensu lato (s.l.), which produces serious health and economic problems. For human treatment, chemotherapy with albendazole (ABZ), a derivative of benzimidazoles, is widely used. However, due to its low efficacy and the lack of alternatives to ABZ, novel compounds are urgently needed. Aromatic plants exhibit powerful pharmacological activities, are accessible, have a relatively low cost, and have generally mild toxicities, making them an effective choice to traditional therapies. In particular, the pharmaceutical properties of aromatic plants are partially attributed to essential oils (EOs). The aim of the present study was to assess the in vitro and in vivo effects of the combined carvacrol and thymol against E. granulosus sensu stricto (s.s.). The greatest protoscolicidal effect was observed with the 9:1 and 5:5 (carvacrol:thymol) combinations which caused a marked decrease in viability after 6 days post-incubation, agreeing with the ultrastructural changes obtained. Permeation of the cysts and loss of turgidity was observed with the incubation with the different combinations of carvacrol:thymol. In the clinical efficacy study, the combination of thymol (40 mg/kg) and carvacrol (40 mg/kg) caused a tendency to diminish the weight of the cysts in comparison with the control group. On the other hand, the treatment of infected mice with ABZ, thymol or carvacrol, caused a significant decrease in the weight of the cysts. In conclusion, we here demonstrated the efficacy of different concentrations of combined carvacrol and thymol against E. granulosus s.s. protoscoleces and murine cysts, where short periods of treatment were sufficient to achieve a pharmacological effect. Moreover, we observed a reduction in the weight of the cysts in experimentally infected mice after treatment with carvacrol and thymol. The strategy used has an advantage over synthetic drugs because natural compounds are generally safe and non-toxic. Moreover, the combination of two drugs with different modes of action would cause a reduction in the doses and treatment times. Based on the promising results obtained in vitro, in the future, different doses of the combined drugs will be assayed in vivo to determine the potential of these compounds for the treatment of cystic echinococcosis.

Development and characterization of monoterpene loaded microemulsions as novel scolicidal agents

Cystic echinococcosis (CE) is one of the most important zoonotic diseases. The primary treatment is surgery and chemical sterilization of the parasitic layers by injection of a scolicidal agent. Available scolicidals possess side effects, and may cause postoperative complications. Several studies reported the scolicidal properties of monoterpene phenols and alcohols such as carvacrol, thymol, and geraniol. The present study aimed to develop, characterize, and assess monoterpene loaded microemulsions as novel green scolicidals products. For this purpose, microemulsions composing 0.37%, 0.75%, and 1.5% of monoterpenoid(s), thymol, carvacrol, and geraniol, alone or in binary or ternary mixtures were formulated. Samples were analyzed by visual inspection, polarizing optical microscope, and dynamic light scattering (DLS). The stability of the samples was evaluated up to a 3-month storage. For the scolicidal bioassay, samples at different concentrations of 200, 100, 50, 25, and 10 μg/ml were added to wells containing 10⁴ viable protoscoleces and mortality rates were recorded at 2, 5, 10, and 20 min after exposure. Results of the present study showed that microemulsions formulated with 0.75% of pure carvacrol or the binary mixture of thymol and carvacrol at 0.375% are promising scolicidal agents.

Protoscolicidal activity of Atriplex halimus leaves extract against Echinococcus granulosus protoscoleces

Cystic echinococcosis, an endemic zoonosis in Algeria, is caused by the development of the helminth Echinococcus granulosus. Surgery remains the main treatment despite inducing relapse and several adverse reactions. In this context, natural scolicidal agents seem to be promising tools to overcome these reactions. In our study, we evaluated the phytochemical contents, antioxidant activity and scolicidal effect of Atriplex halimus. In this context, the aqueous extract from AH leaves (AHE) was subjected to preliminary phytochemical screening by HPLC. The in vitro antioxidant activity was determined by DPPH test. The cytotoxicity of AHE was evaluated in murine peritoneal macrophages and cell viability was examined by MTT assay. Moreover, different concentrations of AHE (20, 40, 50, 60 and 100 mg/ml) were tested on E. granulosus protoscoleces (PSC) cultures, during different times of incubation (15, 30, 60, 90, 120 and 180 min). The viability was evaluated by eosin exclusion test. The morphological and ultrastructural damages were evaluated by SEM. Our results indicate that total phenolic and flavonoids contents were 37.93 μg of Gallic acid equivalent per mg of extract (GAE/mg E) and 18.86 μg of Quercetin equivalent per mg (QE/mg E) respectively. Furthermore, AHE has an antioxidant activity with an IC50 of 0.95 mg/ml. Interestingly, the extracts did not exhibit any cytotoxic effect against murine peritoneal macrophages. Moreover, our study indicated a significant scolicidal activity time- and dose-dependent. At 60 and 100 mg/ml; and after 120 min of incubation; the mortality rate was 99.36 and 100%, respectively. The parasite's tegument is one of the plant's targets as demonstrated by SEM. Our findings show the benefits of Atriplex halimus extract as a new promising scolicidal tool in hydatid cyst treatment.

The effects of Zataria multiflora aromatic water and nano emulsion of Z. multiflora essential oil on the serum level of IFN-γ and IL-4 in mice with hydatidosis

The aim of the present investigation was to evaluate the impacts of Zataria multiflora aromatic water (ZMAW) and nano emulsion (NE) of Z. multiflora essential oil (ZMEO) on IL-4 (Th2-derived cytokine) and IFN-γ (Th1-derived cytokine) concentrations in mice with hydatidosis. Sixty four healthy BALB/c female mice were intraperitoneally injected by 1500 live protoscoleces of Echinococcus granulosus. Five month after injection, the infected mice were divided into seven treatment groups, including: Albendazole (100 mg/kg), ZMAW (100 ml/L), Albendazole 100 + ZMAW (Albendazole 100 mg/kg and ZMAW 100 ml/L), Albendazole 50 + ZMAW (Albendazole 50 mg/kg and ZMAW 100 ml/L), Albendazole 100 + NE of ZMEO (Albendazole 100 mg/kg and NE of ZMEO 10 ml/L), albendazole 50 + NE of ZMEO (albendazole 50 mg/kg and NE of ZMEO 10 ml/L) and the control group with no treatment. The mice received the ZMAW, NE of ZMEO and/or albendazole through drinking water for 90 days. At the end of treatment (90 days), blood specimens were harvested from all mice. A significant reduction in IL-4 concentration was revealed in the albendazole 50 group + NE of ZMEO, when compared to the control group (P < 0.05). No significant difference was noticed for the IFN-γ concentration between the trial groups. Increased IFN-γ: IL-4 ratio was observed in the albendazole 50 + ZMAW, Albendazole 50 + NE of ZMEO, Albendazole 100 + NE of ZMEO groups in comparison with the control group (P < 0.05). The findings observed in the current study showed that the administration of ZMAW and NE of ZMEO along with albendazole could enhance the IFN-γ: IL-4 ratio (Th1/Th2 balance), which may have therapeutic value in the treatment of hydatid disease.

Effects of Zataria multiflora essential oil on the germinative cells of Echinococcus granulosus

Background

Novel and more efficient compounds are urgently required for medical treatment of cystic echinococcosis (CE). Germinative cell culture of Echinococcus granulosus could be used for anti-echinococcosis agent tests and other biological studies on CE. This study was performed to establish an in vitro cell culture model for E. granulosus germinative cells and to evaluate the lethal effect of Zataria multiflora essential oil (ZMEO) on the cultured cells.

Methods

The inner surface of germinal layers of CE cysts was scraped, and the obtained materials were trypsinized to obtain a suspension of single germinative cells. Medium 199 was used as the basic culture medium and was supplemented with fetal bovine serum, 2-mercaptoethanol, l-cysteine, l-glutamine, glucose, sodium pyruvate, hydatid fluid, amphotericin B and antibiotics. The cells were cultured at a concentration of 10⁴ cells/ml of culture medium and incubated at 37 °C. The culture medium was replaced every 7 days. Chemical composition of ZMEO was identified by GC-MS analysis. ZMEO was tested at concentrations of 0.5–8 mg/ml. Viability of the cells was assessed by trypan blue exclusion assay.

Results

A significant increase in the cell number was evident at 20, 30 and 45 days after cultivation. At 45 days of cultivation, the number of cells was approximately five-fold higher than on the first day. In GC-MC analysis, carvacrol, p-cymene, g-terpinene and thymol were found to be the main compounds of ZMEO. The lethal effect of ZMEO on the germinative cells at concentrations of 6, 7 and 8 mg/ml was 100% after 60, 25 and 7 min of exposure, respectively.

Conclusions

At 45 days of cultivation, the cell concentration was suitable for the desired in vitro experiments. A high lethal effect of ZMEO on the germinative cells of E. granulosus may be considered an opportunity for the introduction of a novel, more effective and safer therapeutic agent for treatment of CE using an herbal product.

Graphic abstract

Effect of Taxus baccata L. Extract on Hydatid Cyst Protoscolices In vitro

Hydatidosis is the most important global parasitic infectious disease both in humans and animals, which can lodge at different organs of the host, such as liver, lung (even heart), and brain which may lead to death. Surgery is the main method for the treatment of hydatidosis. In surgical therapy of hydatidosis, the use of sporicidal agents is very important since these agents inactivate live protoscolices and prevent recurrence of infection. Presently, numerous scolicidal chemical agents have been administrated to inactivate the hydatid cyst contents. Recently, there has been a high tendency among researchers to evaluate and present herbal plants as alternative option due to inexpensiveness, availability, low side effects, and toxicity. This study aimed to evaluate the scolicidal effect of hydro alcoholic Taxus baccata L. extract in vitro for the first time. The scolicidal activities of the extract were tested in concentrations of 50, 100, and 150 mg/ml following 10, 30, and 60 min of incubation, and the experiments were performed in triplicate. Viability of protoscolices was confirmed by 0.1% eosin vital staining. The data were analyzed in SAS software (version 9.4). The results showed that the hydroalcoholic extract of Taxus baccata L. at the concentration of 150 mg/ml led to killing 66.6% of protoscolices at 60 min. according to the results of this investigation, it is recommended to use this plant as a scolicidal plant. The findings of the present study showed that Taxus baccata L. had potent scolicidal effects. However, further studies are required to evaluate the efficacy of Taxus baccata L. in vivo.

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.

In Vitro Scolicidal Activity of the Sesquiterpenes Isofuranodiene, α-Bisabolol and Farnesol on Echinococcus granulosus Protoscoleces

Cystic echinococcosis (CE) remains an important challenge both in humans and animals. There is no safe and suitable remedy for CE, so the discovery of new compounds with promising scolicidal effects, particularly from herbal sources, is of great importance for therapeutic uses in the treatment and prevention of CE reappearance. Sesquiterpenes are C15 organic compounds made up of three isoprene units and mostly occurring as fragrant components of essential oils. They are of economic importance for the cosmetic and pharmaceutical industry, and recently attracted the attention of the scientific community for their remarkable parasiticidal properties. In the present study, we have focused on three known sesquiterpenes, isofuranodiene (IFD), α-bisabolol (BSB), and farnesol (FOH), as important phytoconstituents of the essential oils of wild celery (Smyrnium olusatrum), chamomile (Matricaria chamomilla), and acacia farnese (Vachellia farnesiana), respectively. Protoscoleces were recovered from fertile hydatid cysts and were exposed to different concentrations of the three tested compounds for different exposure times. The viability of protoscoleces was confirmed by 0.1% eosin staining. Results of scolicidal activity evaluations showed that IFD possessed the best effect against Echinococcus granulosus protoscoleces (LC₅₀ and LC₉₀ values of 8.87 and 25.48 µg/mL, respectively), followed by BSB (LC₅₀ of 103.2 µg/mL) and FOH (LC₅₀ of 113.68 µg/mL). The overall toxicity of IFD differed significantly from those of FOH and BSB, while there was no significant difference in toxicity between the latter compounds (p > 0.05). The present study showed that IFD seems to be a promising scolicidal agent and can be further tested to become a candidate for CE treatment.

Study on the effect of an ion channel inhibitor "Fluralaner" on Echinococcus granulosus protoscolices and metacestode layers in vitro

Hydatid disease has a great impact on public health, causing high morbidity and mortality. Main lines of treatment include surgery, which mostly requires the installation of a scolicidal agent into hydatid cysts to prevent dissemination. Alternatively, medical treatment involves the use of benzimidazole drugs; however, the results are not satisfactory, and new drug compounds are urgently needed. Fluralaner is a potent inhibitor of GABA-gated chloride channels and L-glutamate-gated chloride channels (GluCls) providing immediate and persistent flea, tick and mite control in dogs after a single oral dose. Researches previously identified different genes encoding ion channels in Echinococcus granulosus, making ion channel inhibitors a promising target for treating hydatid disease. Thus, the present study aimed to evaluate the effect of fluralaner on protoscolices and metacestode layers. Parasite materials (Protoscolices, Metacestodes layers) were exposed to different concentrations of the drug ranging from "12.5-100 ug/ml" and examined for viability after 1, 6 and 24 h. Morphological and ultrastructural alterations were recorded by both light and electron microscopies. Immunohistochemical staining confirmed caspase-3 activation as an indicator of apoptosis- induced therapy. The treated protoscolices and metacestode layers showed loss of the viability, the formation of vacuoles and lipid droplets, separation of the germinal layer, and damage in the laminated layer; apoptosis was prominent after treatment. These findings revealed that fluralaner has a potent scolicidal activity and suggested its therapeutic potential against hydatid disease. Further evaluations for animals and human use in the treatment and prevention of hydatid disease are needed.

In vitro efficacy study of Cinnamomum zeylanicum essential oil and cinnamaldehyde against the larval stage of Echinococcus granulosus

Hydatidosis or cystic echinococcosis is a disease caused by the larval stage of Echinococcus granulosus sensu lato. Chemotherapy can be used alone or in combination with surgery or percutaneous treatment. Benzimidazoles are the only agents used and approved for treatment, but their efficacy is extremely variable. Therefore, it is necessary to find new drugs to improve the treatment of this disease. In the last decades, the biological properties of essential oils and their components began to be investigated as alternatives in the treatment of different ailments. The aim of the present work was to evaluate the in vitro efficacy of the essential oil of Cinnamomum zeylanicum (cinnamon) and cinnamaldehyde against protoscoleces and metacestodes of E. granulosus. The essential oil and cinnamaldehyde, its major component, showed a dose and time dependent effect against protoscoleces. However, cinnamaldehyde showed a greater protoscolicidal effect than the essential oil. The maximum protoscolicidal effect was found with 50 μg/mL of cinnamaldehyde. Viability decreased by 1.7 ± 0.8% after 4 days of incubation and reached 0% at 8 days. Interestingly, there were no significant differences between the activity of cinnamaldehyde at the concentrations of 25 and 10 μg/mL and the efficacy observed with the essential oil at 200 and 50 μg/mL, respectively. Cinnamaldehyde also had a strong in vitro effect against murine cysts, while only the higher concentration of the essential oil caused ultrastructural alterations. Working with components instead of with essential oils has some advantages, particularly in relation to the reproducibility of the formulations and their effectiveness. For this reason, the results obtained in this work are promising in the search for pharmaceutical alternatives for the treatment of cystic echinococcosis.

Subcutaneous Hydatid Cyst in Laboratory Mice: Is it a Suitable Method for Evaluating Therapeutic Agents against Hydatid Cyst?

Hydatid disease is an economic and public health concern in many countries. Currently, surgery is the main treatment option for hydatid disease. In the surgical treatment of hydatidosis, the use of scolicidal agents is very important due to inactivating live protoscoleces and preventing the recurrence of infection. Therefore, it is necessary to investigate newscolicidal agents and novel medications with higher safety and efficacy. In the previous in vitro studies, the scolicidal effects of the methanolic extracts and aromatic water of Zataria multiflora (Z. multiflora) have been demonstrated. Consequently, in this study, the impact of the nanoemulsion of Z. multiflora essential oil on subcutaneous hydatid cysts was compared with albendazole (ABZ). Fifty laboratory male mice were inoculated with 300 viable protoscoleces subcutaneously on the two sides of the abdomen. Following five months of infection, the remaining infected mice (n=42) were allocated into two treatment and one control (without treatment) groups containing fourteen animals each. Group A received ABZ at the dose of 50 mg/kg for 60 days, group B received the nanoemulsions of Z. multiflora at the dose of 50 mg/kg in drinking water for 60 days, and group C was considered as the control group. All the infected mice were euthanized and necropsied two months post-intervention. Afterwards, the cysts were cautiously collected and their number, size, and weight were compared between the mice of different groups. The mean number of hydatid cysts indicated that the nanoemulsion of Z. multiflora essence had a relative superiority to ABZ. On the other hand, the therapeutic effect of ABZ was higher than the nanoemulsion of Z. multiflora essential oil in terms of the mean weight and mean size of hydatid cysts. However, no significant difference was observed between the groups (P&amp;gt;0.5). Overall, the number, weight, and size of cysts were not significantly different between the groups in this investigation. The lack of satisfactory therapeutic results in this study might be due to the location of hydatid cysts in the subcutaneous space.

Antiparasitic effects of Zataria multiflora essential oil nano-emulsion on larval stages of Echinococcus granulosus

Various protoscolicidal agents are indicated for the prevention of recurrence of cystic echinococcosis caused by the larval stage of Echinococcus granulosus; however, most of these chemicals have adverse side effects. This study evaluated the effects of Zataria multiflora essential oil (ZEO) nano-emulsion and emulsion at the concentrations of 1, 2, 5, 10, 15, and 20 µl/ml on E. granulosus protoscoleces. Albendazole (5 mg/ml), normal saline, and nano-emulsion without ZEO served as control groups. Optimal concentrations of ZEO nano-emulsion and emulsion on the microcysts were also investigated. ZEO emulsion at a concentration of 20 µl/ml for the duration of 15 min and nano-emulsion for the duration of 10 min resulted in the death of 100% of the protoscoleces. Additionally, densely packed aggregates were formed inside the microcysts treated with ZEO nano-emulsion and emulsion at a concentration of 20 µl/ml after 40 min, but the complete destruction of laminated layers did not occur. The results indicate that ZEO nano-emulsions have a higher protoscolicidal effect than its emulsion, but these two compounds had similar effects on microcysts.

The scolicidal activity of the essential oil obtained from the needles of Pinus nigra Arn. subsp. pallasiana (Lamb.) Holmboe on hydatid cyst

ETHNOPHARMACOLOGICAL RELEVANCE

This study aimed to evaluate the in vitro activity of the essential oil of Pinus nigra subsp. pallasiana against protoscoleces of Echinococcus granulosus sensu lato. In traditional Turkish folk medicine, the essential oils and resin of P. nigra and P. sylvestris are used externally for wound healing. They are also used in cattle for treating worms and as boiling essence against cold and stomachache. Protoscoleces were aseptically aspirated from sheep livers having hydatid cysts.

MATERIALS AND METHODS

Three concentrations (10, 30, and 50 mg/mL) of the essential oil from P. nigra subsp. pallasiana cones were used for 10-60 min. The essential oil was applied to protoscoleces of hydatid cyst to determine the scolicidal activity of the essential oil. Viability of protoscoleces was observed by 0.1% eosin staining.

RESULTS

The rate of dead protoscoleces was found to be 2.27% in the control group, which was not treated with essential oil. The rate of dead protoscoleces increased to 61.69%, 69.39%, 75.98% and 71.76% respectively after, 10, 20, 30, and 60 min when the protoscoleces were exposed to the P. nigra subsp. pallasiana essential oil at 10 mg/mL concentration. When protoscoleces were exposed to the essential oil of P. nigra subsp. pallasiana for 10, 20, 30, and 60 min at 30 mg/mL concentration, the mortality rates of protoscoleces were determined as 3.82%, 91.33%, 94.67% and 96.74%, respectively. The mortality rate of 100% was determined at 50 mg/mL concentration after 60 min of exposure. According to statistical analysis, P. nigra subsp. pallasiana essential oil at all concentrations had significant scolicidal effects compared to the control group at all exposure times.

CONCLUSIONS

The essential oil of P. nigra subsp. pallasiana needles showed scolicidal activity and it could be a new scolicidal agent for using in hydatid cyst treatment.

Nanoemulsions of Essential Oils: New Tool for Control of Vector-Borne Diseases and In Vitro Effects on Some Parasitic Agents

The control of infectious/parasitic diseases is a continuing challenge for global health, which in turn requires new methods of action and the development of innovative agents to be used in its prevention and/or treatment. In this context, the control of vectors and intermediate hosts of etiological agents is an efficient method in the prevention of human and veterinary diseases. In later stages, it is necessary to have bioactive compounds that act efficiently on the agents that produce the disease. However, several synthetic agents have strong residual effects in humans and other animals and cause environmental toxicity, affecting fauna, flora and unbalancing the local ecosystem. Many studies have reported the dual activity of the essential oils (EOs): (i) control of vectors that are important in the cycle of disease transmission, and (ii) relevant activity against pathogens. In general, EOs have an easier degradation and cause less extension of environmental contamination. However, problems related to solubility and stability lead to the development of efficient vehicles for formulations containing EOs, such as nanoemulsions. Therefore, this systematic review describes several studies performed with nanoemulsions as carriers of EOs that have larvicidal, insecticidal, repellent, acaricidal and antiparasitic activities, and thus can be considered as alternatives in the vector control of infectious and parasitic diseases, as well as in the combat against etiological agents of parasitic origin.

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.

Anthelmintic effect of thymol and thymol acetate on sheep gastrointestinal nematodes and their toxicity in mice

Thymol is a monoterpene and acetylation form of this compound can reduce the toxicity and enhance its biological effects. The objective of this study was to evaluate the effect of thymol and thymol acetate (TA) on egg, larva and adult Haemonchus contortus and the cuticular changes, acute toxicity in mice and the efficacy on sheep gastrointestinal nematodes. In vitro tests results were analyzed by analysis of variance (ANOVA) and followed by comparison with Tukey test or Bonferroni. The efficacy of in vivo test was calculated by the BootStreet program. In the egg hatch test (EHT), thymol (0.5 mg/mL) and TA (4 mg/mL) inhibited larval hatching by 98% and 67.1%, respectively. Thymol and TA (8 mg/mL) inhibited 100% of larval development. Thymol and TA (800 µg/mL) reduced the motility of adult worms, by 100% and 83.4%, respectively. Thymol caused cuticular changes in adult worm teguments. In the acute toxicity test, the LD50 of thymol and TA were 1,350.9 mg/kg and 4,144.4 mg/kg, respectively. Thymol and TA reduced sheep egg count per gram of faeces (epg) by 59.8% and 76.2%, respectively. In in vitro tests thymol presented better anthelmintic activity than TA. However TA was less toxic and in in vivo test efficacy was similar.

Albendazole nanocrystals in experimental alveolar echinococcosis: Enhanced chemoprophylactic and clinical efficacy in infected mice

Human alveolar echinococcosis is caused by the fox tapeworm Echinococcus multilocularis and is usually fatal if left untreated. Medical treatment with albendazole (ABZ) remains an effective option. However, due to its low aqueous solubility, ABZ is poorly and erratically absorbed following oral administration resulting in low drug levels in plasma and liver distribution. Thus, there arises the need to find a simple, efficient and scalable method to produce new ABZ formulations with increased bioavailability. Bearing this in mind, ABZ nanocrystals (ABZ-NCs) appears to be a useful tool to achieve this goal. The aim of the current study was to investigate the chemoprophylactic and clinical efficacy of an ABZ-NC formulation on mice infected with E. multilocularis. In the chemoprophylactic efficacy study, mean weight of the cysts recovered from the ABZ-NC group was 50% lower than that recorded from untreated mice, whereas the treatment with ABZ suspension did not show preventive effect. The viability of protoscoleces isolated from ABZ-NC treated mice was significantly lower than control groups. In the clinical efficacy studies, both ABZ formulations resulted in a reduction in the mean weight of the cysts obtained from mice, however only the treatment with the nanosuspension revealed significant differences (P < 0.05) compared to the control groups. Treatment with ABZ-NCs reduced the weight of the cysts by 77% and the viability of their protoscoleces to 34%. All these results coincided with the tissue damage determined at the ultrastructural level. The enhanced chemoprophylactic and clinical efficacy of ABZ-NCs observed in this study could be attributed to an increase in the oral bioavailability of the drug. In a next step, we will characterize the cyst concentration profile after the administration of ABZ-NCs in mice infected with E. multilocularis.

In vitro and in vivo antihydatid activity of a nano emulsion of Zataria multiflora essential oil

In in vitro process of this study, protoscoleces of the hydatid cysts were exposed to two concentrations of nano emulsion (NE) of Zataria multiflora essential oil (ZMEO) (1 and 2mg/mL) for 10 and 20min. Viability of protoscoleces was confirmed using 0.1% eosin staining. For in vivo studies, sixteen laboratory mice were infected intraperitoneally by 1500 live protoscoleces. Five months after infection, the infected mice were divided into treatment and control groups. The mice of treatment group received the NE of ZMEO (20mg/kg) orally via their drinking water while the mice of control group received no treatment. Two months after the start of treatment, all of the mice were necropsied and the hydatid cysts were collected. Subsequently, the numbers, sizes and weights of the collected cysts were compared between the mice of two groups. The results of in vitro scolicidal assays showed that the scolicidal power of NE of a ZMEO at concentration of 1mg/mL was 88.01%, and 100% after 10 and 20min respectively. NE of ZMEO showed 100% scolicidal power at a concentration of 2mg/mL after 10min (comparing to 4.46% for the control group). The results of in vivo studies revealed that the size of the largest cysts as well as the total number of the cysts were significantly lower in the mice treated with NE of ZMEO (P<0.05). In conclusion, NE of ZMEO may be considered as a natural scolicidal agent and a potential therapeutic tool for treatment of hydatid disease.

In vitro and in vivo efficacy of carvacrol against Echinococcus granulosus

Currently, benzimidazoles are used as chemotherapeutic agents and as a complement to surgery and PAIR in the treatment of cystic echinococcosis (CE). They are generally applied at high doses causing side effects and, 50% of cases do not respond favorably to such chemotherapy. The use of essential oils obtained by distillation from aromatic plants would be an effective alternative or complementary to the synthetic compounds, because would not bring the appearance of side effects. Carvacrol and his isomer thymol are the main phenolic components from essential oils of Origanum vulgare (oregano) and Thymus vulgaris (thyme). The aim of the present work was to evaluate the in vitro and in vivo efficacy of carvacrol against Echinococcus granulosus metacestodes. For the in vitro assay, protoscoleces and cysts of E. granulosus were incubated with carvacrol at the following final concentrations: 10, 5 and 1μg/ml of carvacrol. The maximum protoscolicidal effect was found with 10μg/ml of carvacrol. Results of viability tests were consistent with the structural and ultrastructural damage observed in protoscoleces. Ultrastructural studies revealed that the germinal layer of cysts treated with carvacrol lost the multicellular structure feature. In the clinical efficacy study, a reduction in cyst weight was observed after the administration of 40mg/kg of carvacrol during 20days in mice with cysts developed during 4 months, compared to that of those collected from control mice. Given that the in vivo effect of carvacrol was comparable with the treatment of reference with ABZ and the fact that is a safe compound, we postulated that carvacrol may be an alternative option for treatment of human CE.

In vitro effectiveness of Curcuma longa and Zingiber officinale extracts on Echinococcus protoscoleces

Hydatid disease is an important economic and human public health problem with a wide geographical distribution. Surgical excision remains the primary treatment and the only hope for complete cure of hydatosis. The most important complications arising from surgical excision, however, is recurrence, which is due to dissemination of protoscolices during the surgery. Pre-surgical inactivation of the contents of the hydatid cyst by injection of scolicidal agent into the cyst has been used as adjunct to surgery in order to overcome the risk of recurrence. In the present study, ethanolic extracts of turmeric (Curcuma longa) and ginger (Zingiber officinale) were tested as scolicidal agent for Echinococcus protoscoleces. Protoscoleces were collected aseptically from sheep livers containing hydatid cysts. Three concentrations (10, 30 and 50 mg/ml) of each extract were investigated and viability of the protoscoleces was tested by 0.1% eosin staining. Ginger extract showed the strongest scolicidal effect (100%) after 20 min at a concentration of 30 mg/ml and 10 min at 50 mg/ml. The maximum scolicidal effect of turmeric was 93.2% after 30 min at a concentration of 50 mg/ml. It is concluded that turmeric and ginger extracts have high scolicidal activity and could be used as effective scolicidal agents against Echinococcus protoscoleces.

In vivo activity of albendazole in combination with thymol against Echinococcus multilocularis

Human alveolar echinococcosis (AE) is caused by the fox tapeworm Echinococcus multilocularis and is usually lethal if left untreated. The current strategy for treating human AE is surgical resection of the parasite mass complemented by chemotherapy with benzimidazole compounds. However, reliable chemotherapeutic alternatives have not yet been developed stimulating the research of new treatment strategies such as the use of medicinal plants. The aim of the current study was to investigate the efficacy of the combination albendazole (ABZ)+thymol on mice infected with E. multilocularis metacestodes. For this purpose, mice infected with parasite material were treated daily for 20 days with ABZ (5 mg/kg), thymol (40 mg/kg) or ABZ (5 mg/kg)+thymol (40 mg/kg) or left untreated as controls. After mice were euthanized, cysts were removed from the peritoneal cavity and the treatment efficacy was evaluated by the mean cysts weight, viability of protoscoleces and ultrastructural changes of cysts and protoscoleces. The application of thymol or the combination of ABZ+thymol resulted in a significant reduction of the cysts weight compared to untreated mice. We also found that although ABZ and thymol had a scolicidal effect, the combination of the two compounds had a considerably stronger effect showing a reduction in the protoscoleces viability of 62%. These results were also corroborated by optical microscopy, SEM and TEM. Protoscoleces recovered from ABZ or thymol treated mice showed alterations as contraction of the soma region, rostellar disorganization and presence of blebs in the tegument. However both drugs when combined lead to a total loss of the typical morphology of protoscoleces. All cysts removed from control mice appeared intact and no change in ultrastructure was detected. In contrast, cysts developed in mice treated with ABZ revealed changes in the germinal layer as reduction in cell number, while the treatment with thymol or the ABZ+thymol combination predominantly showed presence of cell debris. On the other hand, no differences were found in alkaline phosphatase (AP), glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) activities between control and treated mice, indicating the lack of toxicity of the different drug treatments during the experiment. Because combined ABZ+thymol treatment exhibited higher treatment efficiency compared with the drugs applied separately against murine experimental alveolar echinococcosis, we propose it would be a useful option for the treatment of human AE.

Chrysanthemum boreale flower floral water inhibits platelet-derived growth factor-stimulated migration and proliferation in vascular smooth muscle cells

CONTEXT

Chrysanthemum boreale Makino (Compositae) (CBM) is a traditional medicine that has been used for the prevention or treatment of various disorders; it has various properties including antioxidation, anti-inflammation, and antitumor.

OBJECTIVE

The present study was designed to explore the in vitro effect of CBM flower floral water (CBMFF) on atherosclerosis-related responses in rat aortic smooth muscle cells (RASMCs).

MATERIALS AND METHODS

CBMFF was extracted from CBM flower by steam distillation and analyzed using gas chromatography-mass spectrometry. The anti-atherosclerosis activity of CBMFF was tested by estimating platelet-derived growth factor (PDGF)-BB (10 ng/mL)-induced proliferation and migration levels and intracellular kinase pathways in RASMCs at CBMFF concentrations of 0.01-100 μM and analyzing ex vivo aortic ring assay.

RESULTS

Gas chromatography-mass spectrometry showed that the CBMFF contained a total of seven components. The CBMFF inhibits PDGF-BB-stimulated RASMC migration and proliferation (IC50: 0.010 μg/mL). Treatment of RASMCs with PDGF-BB induced PDGFR-β phosphorylation and increased the phosphorylations of MAPK p38 and ERK1/2. CBMFF addition prevented PDGF-BB-induced phosphorylation of these kinases (IC50: 008 and 0.018 μg/mL, for p38 MAPK and ERK1/2, respectively), as well as PDGFR-β (IC50: 0.046 μg/mL). Treatment with inhibitors of PDGFR, P38 MAPK, and ERK1/2 decreased PDGF-BB-increased migration and proliferation in RASMCs. Moreover, the CBMFF suppressed PDGF-BB-increased sprout outgrowth of aortic rings (IC50: 0.047 μg/mL).

DISCUSSION AND CONCLUSION

These results demonstrate that CBMFF may inhibit PDGF-BB-induced vascular migration and proliferation, most likely through inhibition of the PDGFR-β-mediated MAPK pathway; therefore, the CBMFF may be promising candidate for the development of herbal remedies for vascular disorders.

In vivo and in vitro efficacies of mebendazole, mefloquine and nitazoxanide against cyst echinococcosis

Echinococcus granulosus is a cestode parasite. The metacestode stage causes cystic echinococcosis (CE) mainly in the human liver and lung. Current chemotherapy against CE is based on mebendazole and albendazole. However, benzimidazoles result in a low cure rate or are ineffective in many patients; therefore, novel compounds for the treatment of this disease have been studied. Mefloquine was reported to be dramatically effective on cultured Echinococcus multilocularis metacestodes in vitro. And, nitazoxanide has a prominent protoscolicidal effect. However, these compounds have no impact on the growth of cysts harbored in mice. In this study, we investigated the in vitro and in vivo efficacy of mebendazole, mefloquine, and nitazoxanide against E. granulosus protoscoleces, germinal cells, and infected mice. The effect of mebendazole on protoscoleces and germinal cell was proved to be dose-dependent in vitro. And, a reduction of the cyst weight was also the found after oral application of mebendazole to infected mice. Mefloquine (5 and 10 μg/ml) caused death within 24 h of protoscoleces and germinal cells in vitro, whereas a lower concentration of 1 μg/ml was ineffective. In mice infected with E. granulosus, oral mefloquine (200 and 400 mg/kg twice weekly for 2 weeks) showed no reduction in parasite weight. Without affecting the viability of germinal cells and the growth of hydatid cysts, nitazoxanide only showed protoscolicidal effects in infected mice. In conclusion, mebendazole, mefloquine, and nitazoxanide showed various effects on E. granulosus under different conditions. These drugs could be useful to some extent in the treatment of CE.

Efficacy of albendazole in combination with thymol against Echinococcus multilocularis protoscoleces and metacestodes

The larval (metacestode) stage of the tapeworm Echinococcus multilocularis causes alveolar echinococcosis (AE), a mainly hepatic disease characterized by continuous asexual proliferation of metacestodes by exogenous budding, resulting in the tumor-like, infiltrative growth of the parasite lesion. Current chemotherapeutical treatment of AE relies on the use of benzimidazoles, albendazole (ABZ) and mebendazole, but these drugs act parasitostatic rather than parasitocidal, and due to their low success rate they imply a lifelong application causing severe side effects. Thymol is one of the major components of the essential oils of Thymus and is a widely known anti-microbial agent. The aim of the present work was to compare the efficacy of albendazole (ABZ) and thymol separately or combined on E. multilocularis protoscoleces and metacestodes. For this purpose, microscopical examinations at different time points were carried out. Moreover the tegumentary enzyme gamma glutamyl transferase (GGT) was measured to quantify the damage in metacestodes. Even though treatments of in vitro cultured E. multilocularis protoscoleces or metacestodes with ABZ or/and thymol showed that the drugs have an adverse effect on parasite viability, the combination of the two compounds at the concentration of 10μg/ml showed the maximum anti-parasitic effect. Three days postincubation the first effects of the treatment were detected on protoscoleces and a marked reduction in viability (33%) was registered at day 18. Incubation of E. multilocularis metacestodes in the presence of ABZ 10μg/ml+thymol 10μg/ml during 10 days resulted in dramatic alterations such as strongly irregular and fissured surface and markedly disrupted vesicles. Scanning electron microscopy showed that protoscoleces as well as the germinal layer of E. multilocularis metacestodes were dramatically damaged following ABZ or/and thymol treatment. Also an important increase of tegumentary enzyme GGT was registered after 72h postincubation with both drugs. The data reported in this article demonstrate a clear in vitro effect of ABZ+thymol against E. multilocularis protoscoleces and metacestodes.

Effect of Different Terpene-Containing Essential Oils on the Proliferation of Echinococcus granulosus Larval Cells

Human cystic echinococcosis remains a major public health problem on several countries and the treatment strategies are not solved. The aim of the present work was to determine the in vitro effect of thymol and Mentha piperita, M. pulegium, and Rosmarinus officinalis essential oils on the proliferation of E. granulosus larval cells. Isolated cells and cellular aggregates were obtained from hydatid cyst's germinal layer and exposed to 1, 5, and 10 μg/ml of thymol and the different essential oils for 7 days. Drug effect was evaluated using test viability and scanning electron microscopy. Control cell culture viability was 2.1 x 10⁶ (100%) after 7 days of incubation. At day 7, thymol 5 μg/ml caused a reduction in cell viability of 63% and the essential oils of M. piperita 10 μg/ml, M. pulegium 10 μg/ml, and R. officinalis 10 μg/ml produced a reduction in the viability of 77, 82, and 71%, respectively. Moreover essential oils caused reduction in cell number, collapsed cells, and loss of normal tridimensional composition of the aggregates. Due to the inhibitory effect caused by essential oils on E. granulosus cells we suggested that it would be an effective means for suppression of larval growth.

In Vitro Cestocidal Activity of Thymol on Mesocestoides corti Tetrathyridia and Adult Worms

Nothing is known about the possible effect of thymol or other compounds of essential oils against the adult worms of cestodes. The aim of the present work was to determine in vitro cestodicidal activity of thymol against Mesocestoides corti adult worms. Moreover, the in vitro effect on tetrathyridia was also demonstrated. Tetrathyridia exposed to different concentrations of thymol showed a concentration and time-dependent effect. At lower concentrations, the main change observed was mainly in morphology, with larvae exhibiting an elongation of the body. When tetrathyridia were exposed to higher concentrations, increased surface alterations and damage were detected. The body appeared elongated and flattened, and a complete loss of morphology and microtriches was observed. Thymol was able to kill M. corti tetrathyridia, since following inoculation of treated parasites in mice no parasites could be recovered. The effect on M. corti adult worms was dose and time-dependent. Changes in motility coincide with the tissue damage were observed at the structural and ultrastructural level. Thymol caused severe damages to both developmental stages analyzed. Damages were more significant in fully segmented worms. The data reported in this paper demonstrate a clear in vitro effect of thymol against M. corti tetrathyridia and adult worms.

Efficacy of Essential Oils of Thymus vulgaris and Origanum vulgare on Echinococcus granulosus

The aim of the present work was to determine the in vitro effect of T. vulgaris and O. vulgare essential oils against E. granulosus protoscoleces and cysts. Essential oils were added to the medium resulting in thymol final concentrations of 10 μg/mL. The essential oils had a time-dependent effect provoking the complete loss of protoscolex viability after 72 days of postincubation. The results were confirmed at the ultrastructure level. Loss of infectivity in protoscoleces incubated with O. vulgare after 60 days was observed. On the other hand, the weight of cysts recorded in mice inoculated with T. vulgaris treated protoscoleces was significantly lower than that obtained in control group. Gamma-glutamyl-transpeptidase activity was readily detected in the culture supernatant of protoscoleces treated either with the essential oils or thymol. T. vulgaris and O. vulgare essential oils and thymol can induce cell apoptosis of protoscoleces after short incubation times. The efficacy of T. vulgaris and O. vulgare essential oils was also demonstrated in vitro on E. granulosus murine cysts. Our data suggest that essential oils of T. vulgaris and O. vulgare have anthelmintic effect against protoscoleces and cysts of E. granulosus.

In vivo study of the efficacy of the aromatic water of Zataria multiflora on hydatid cysts

Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the chemical composition of the essential oil (EO) from aromatic water (AW) of Zataria multiflora. Thymol (66.9%), carvacrol (15.2%), and carvone (7.3%) were found to be the major EO constituents. Eighty laboratory BALB/c mice were infected intraperitoneally by injection of 1,500 viable protoscolices and were divided into prevention (40 mice) and therapeutic (40 mice) groups. To prove the preventive effect of the Z. multiflora AW on development of hydatid cysts, the 40 infected mice were allocated into three treatment groups, including the albendazole group (10 mice that received 150 mg/kg body weight/day for 10 days), the Z. multiflora AW group (15 mice that received 20 ml/liter in drinking water for 8 months), and a control group (15 mice that received no treatment). To estimate the therapeutic effect of the Z. multiflora AW on the hydatid cyst, after 8 months of infection, the 15 remaining mice were allocated into three experimental treatment groups of five animals each, including the albendazole group (300 mg/kg/day for 20 days), Z. multiflora AW group (40 ml/liter in drinking water for 30 days), and control group (no treatment). All mice were then euthanized, and the sizes and weights of the cysts as well as their ultrastructural changes were investigated. The weights and sizes of the hydatid cysts significantly decreased upon treatment with the Z. multiflora AW in both the preventive and therapeutic groups (P < 0.05). The results of scanning electron microscopy also showed considerable damage in the germinal layer of the hydatid cysts recovered from the treated animals.

Could thymol have effectiveness on scolices and germinal layer of hydatid cysts?

Scolicidal solutions remain indispensable in the treatment of hydatid cyst disease. Properties of an ideal solution would be inexpensiveness and the promotion of a rapid and complete scolicidal effect with an absence of local and systemic side effects. From this point of view, no ideal solution and agents have been described yet. The aim of the present work was to determine the in vitro effect of high concentrations of thymol against protoscoleces, microcyst and cyst of Echinococcus granulosus and to evaluate its possible role as a scolicidal agent during surgery or PAIR. After short exposure times, a rapid effect was observed depending on the parasitic material. After 2 min of exposure to thymol, viability of protoscoleces was approximately 1.3% at a concentration of 250 μg/ml. The protoscolicidal effect is dose and time dependent. The results of the in vitro treatment with thymol were similar in both microcysts and secondary murine cysts. The employment of SEM and TEM allowed us to examine, at an ultrastructural level, the effects induced by thymol on E. granulosus protoscoleces, microcysts and murine cysts. In conclusion, the data obtained clearly demonstrated that thymol caused severe damages to the parasite even after short incubation times. This fact and the lack of toxicity at the evaluated concentrations, allow us to propose it as a possible scolicidal agent during hydatid cysts surgery and/or PAIR.

In vitro scolicidal effect of Satureja khuzistanica (Jamzad) essential oil

OBJECTIVE

To investigate the scolicidal effect of the Satureja khuzistanica (S. khuzistanica)essential oil from aerial parts of this herbal plant.

METHODS

The essential oil was obtained by hydrodistillation method. Gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS) were employed to determine the chemical composition of the essential oil. Protoscolices were collected aseptically from sheep livers containing hydatid cyst. Protoscolices were exposed to various concentrations of the oil (3, 5 and 10 mg/mL) for 10, 20, 30, and 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining.

RESULTS

: A total of 19 compounds representing 97.6% of the total oil, were identified. Carvacrol (94.9%) was found to be the major essential oil constituent. Scolicidal activity of S. khuzistanica essential oil at concentration of 3 mg/mL was 28.58, 32.71, 37.20 and 42.02%, respectively. This essential oil at concentration of 5 mg/mL killed 51.33, 66.68, 81.12, and 100% of protoscolices after 10, 20, 30 and 60 min, respectively. One hundred scolicidal effect was observed with S. khuzistanica essential oil at the concentration of 10 mg/mL after 10 min (comparing with 7.19% for control group).

CONCLUSIONS

The essential oil of S. khuzistanica is rich in carvacrol and may be used as a natural scolicidal agent.

Echinococcus granulosus tegumental enzymes as in vitro markers of pharmacological damage: a biochemical and molecular approach

Cystic echinococcosis is a chronic, complex, and neglected disease. Novel therapeutical tools are needed to optimize human treatment. A number of compounds have been investigated, either using in vitro cultured parasites and/or applying in vivo rodent models. Although some of these compounds showed promising activities in vitro, and to some extent also in the rodent models, they have not been translated into clinical applications. Membrane enzyme activities in culture supernatants of treated protoscoleces with calcium modulator drugs and anthelmintic drugs were measured and provided an indication of compound efficacy. This work describes for the first time the detection of alkaline phosphatase, gamma-glutamyl-transpeptidase and acetylcholinesterase activities in supernatants of in vitro treated Echinococcus granulosus protoscoleces. Marked differences on the enzymatic activities in supernatants from drug treated cultures were detected. We demonstrated that those genes that show the highest degree of conservation when compared to orthologs, are constitutively and highly expressed in protoscoleces and metacestodes. Due to high sensibility and the lack of activity in supernatants of intact protoscoleces, gamma-glutamyl-transpeptidase is proposed as the ideal viability marker during in vitro pharmacological studies against E. granulosus protoscoleces.

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.

In vitro effects of some herbs used in Egyptian traditional medicine on viability of protoscolices of hydatid cysts

The present work evaluated the effects of alcoholic extracts of salvia (Salvia officinalis), thyme (Thymus vulgaris), and 2 pure compounds (thymol and menthol) on the viability of Echinococcus granulosus protoscolices in vitro. Four different concentrations of each extract (2,500, 1,500, 1,000, and 500 µg/ml) and 3 different concentrations each of thymol and menthol (50, 10, and 1 µg/ml) were used. Concentration of 2,500 µg/ml of both extracts showed a significant protoscolicidal activity on the 6th day. Complete loss of viability of protoscolices occurred with 500 µg/ml concentration of both extracts at day 6 and day 7 post-treatment (PT), respectively. Pure compounds, i.e., menthol and thymol, showed potent effects with 50 µg/ml concentration at day 2 and day 5 PT, respectively. These effects were compared with those of albendazole sulfoxide (800 µg/ml), a commonly used treatment drug for hydatidosis. Krebs-Ringer solution and the hydatid cystic fluid at a ratio of 4:1 was a good preservative solution which kept the protoscolices viable for 15 days.

Anthelmintic effect of Mentha spp. essential oils on Echinococcus granulosus protoscoleces and metacestodes

The aim of the present work was to determine the in vitro effect of Mentha piperita and Mentha pulegium essential oils against Echinococcus granulosus and to compare the effectiveness of both oils according to the exposure time and concentration. Although both treatments had a protoscolicidal effect, M. pulegium had a considerably stronger effect than M. piperita. Essential oil of M. pulegium produced dose- and time-dependent effects. Maximal protoscolicidal effect was observed after 12 days of incubation and reached 0% after 18 days. This lack of viability was proved during the determination of infectivity into mice. Essential oil of M. piperita produced only a time-dependent effect. At 24 days p.i., the viability of protoscoleces decreased to approximately 50%. Scanning and transmission electron microscopy (SEM and TEM) demonstrated the drug-induced ultrastructural damage. On the other hand, a loss of turgidity was detected in all M. pulegium-treated cysts respective of the drug concentration. There was a correlation between the intensity of damage and the concentration of the essential oil assayed. Studies by SEM revealed that the germinal layer of treated cysts lost the feature multicellular structure. M. pulegium essential oil showed piperitone oxide as main compound in their composition, and we suggest that this component could be responsible of the markedly anthelmintic effect detected. Our data suggest that essential oils of Mentha spp. can be a promising source of potential protoscolicidal agents. The isolation of active anthelmintic constituents is in progress and may lead to the discovery of compounds with improved therapeutic value.

[Study of lesional aspects of hydatid echinococcosis in man in Mauritania: fertility, histology of hydatid cysts and protoscolex viability]

A lesional study on human hydatidosis (localization, fertility of cysts, protoscolex viability, and histological structure) focused on 63 human hydatid cysts from patients operated at CHN of Nouakchott was conducted during the period 1997-2007. The authors report the following results: the annual surgical incidence rate was in the order of 1.2% per 100,000 inhabitants. The lung was the primary localization of cyst (52%) followed by the liver (33%), spleen (4%), brain (3%), heart (2%), breasts (2%), kidney (2%), diaphragm (1%), and peritoneum (1%). The pulmonary cysts were larger and more fertile (76%) with protoscoleces also more viable (70%) compared with liver cysts (67-62%). The histology of hydatid cysts revealed in most cases a histological structure consistent with that described in the literature: thick cuticle, membrane proligeous, and capsules visible.

Echinococcus metacestodes as laboratory models for the screening of drugs against cestodes and trematodes

Among the cestodes, Echinococcus granulosus, Echinococcus multilocularis and Taenia solium represent the most dangerous parasites. Their larval stages cause the diseases cystic echinococcosis (CE), alveolar echinococcosis (AE) and cysticercosis, respectively, which exhibit considerable medical and veterinary health concerns with a profound economic impact. Others caused by other cestodes, such as species of the genera Mesocestoides and Hymenolepis, are relatively rare in humans. In this review, we will focus on E. granulosus and E. multilocularis metacestode laboratory models and will review the use of these models in the search for novel drugs that could be employed for chemotherapeutic treatment of echinococcosis. Clearly, improved therapeutic drugs are needed for the treatment of AE and CE, and this can only be achieved through the development of medium-to-high throughput screening approaches. The most recent achievements in the in vitro culture and genetic manipulation of E. multilocularis cells and metacestodes, and the accessability of the E. multilocularis genome and EST sequence information, have rendered the E. multilocularis model uniquely suited for studies on drug-efficacy and drug target identification. This could lead to the development of novel compounds for the use in chemotherapy against echinococcosis, and possibly against diseases caused by other cestodes, and potentially also trematodes.