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.

In vitro effects of tropisetron and granisetron against Echinococcus granulosus (s.s.) protoscoleces by involvement of calcineurin and calmodulin.

BACKGROUND: Cystic echinococcosis (CE) is a disease caused by the larval stage of Echinococcus granulosus sensu lato  (s.l.). The treatment of CE mainly relies on the use of benzimidazoles, which can commonly cause adverse side effects. Therefore, more efficient treatment options are needed. Drug repurposing is a useful approach for advancing drug development. We have evaluated the in vitro protoscolicidal effects of tropisetron and granisetron in E. granulosus sensu stricto (s.s.) and assessed the expression of the calcineurin (CaN) and calmodulin (CaM) genes, both of which have been linked to cellular signaling activities and thus are potentially promising targets for the development of drugs. METHODS: Protoscoleces (PSC) of E. granulosus (s.s.) (genotype G1) obtained from sheep hepatic hydatid cysts were exposed to tropisetron and granisetron at concentrations of 50, 150 and 250 µM for various periods of time up to 10 days. Cyclosporine A (CsA) and albendazole sulfoxide were used for comparison. Changes in the morphology of PSC were investigated by light microscopy and scanning electron microscopy. Gene expression was assessed using real-time PCR at the mRNA level for E. granulosus calcineurin subunit A (Eg-CaN-A), calcineurin subunit B (Eg-CaN-B) and calmodulin (Eg-CaM) after a 24-h exposure at 50 and 250 µM, respectively. RESULTS: At 150 and 250 µM, tropisetron had the highest protoscolicidal effect, whereas CsA was most effective at 50 µM. Granisetron, however, was less effective than tropisetron at all three concentrations. Examination of morphological alterations revealed that the rate at which PSC were killed increased with increasing rate of PSC evagination, as observed in PSC exposed to tropisetron. Gene expression analysis revealed that tropisetron at 50 µM significantly upregulated Eg-CaN-B and Eg-CaM expression while at 250 µM it significantly downregulated both Eg-CaN-B and Eg-CaM expressions; in comparison, granisetron decreased the expression of all three genes at both concentrations. CONCLUSIONS: Tropisetron exhibited a higher efficacy than granisetron against E. granulosus (s.s.) PSC, which is probably due to the different mechanisms of action of the two drugs. The concentration-dependent effect of tropisetron on calcineurin gene expression might reflect its dual functions, which should stimulate future research into its mechanism of action and evaluation of its potential therapeutical effect in the treatment of CE.

Copper nanoparticles: Biosynthesis, characterization, and protoscolicidal effects alone and combined with albendazole against hydatid cyst protoscoleces.

BACKGROUND: Surgery remains the preferred treatment option for hydatid cyst (cystic echinococcosis); however, recent studies have demonstrated that the current protoscolicidal agents used during surgery are associated with some adverse side effects such as biliary fibrosis, hepatic necrosis, and cirrhosis. The present study aims to evaluate the in vitro and ex vivo anti-parasitic effects of copper nanoparticles (CuNPs) alone and combined with albendazole on hydatid cyst protoscoleces. METHODS: CuNPs was green synthesized using C. spinosa extract. Various concentrations of CuNPs (250, 500, and 750 mg/mL) alone and combined with albendazole (ALZ, 200 mg/mL) were exposed to protoscoleces collected from the liver fertile hydatid cysts of infected sheep for 5-60 min in vitro and ex vivo. Next, the eosin exclusion test was applied to determine the viability of protoscoleces. Caspase-3 like activity of CuNPs-treated protoscoleces was then evaluated using the colorimetric protease assay Sigma Kit based on the manufacturer's instructions. RESULTS: Scanning electron microscopy (SEM) results showed that the particle size of CuNPs was 17 and 41 nm with the maximum peak at the wavelength of 414 nm. The maximum protoscolicidal activity of CuNPs was observed at the concentration of 750 mg/mL in vitro, so that 73.3 % of protoscoleces were killed after 60 min of exposure. Meanwhile, the mortality of protoscoleces was 100 % after 10 min of exposure to 750 mg/mL of CuNPs along with ALZ (200 mg/mL). Nevertheless, the findings proved that CuNPs even in combination with ALZ required a longer time to kill protoscoleces ex vivo. After 48 h of treating protoscoleces, CuNPs in a dose-dependent manner and at doses of 250, 500, and 750 mg/mL induced the caspase enzyme activation by 20.5 %, 32.3 %, and 36.1 %, respectively. CONCLUSION: The findings of the present investigation showed potent protoscolicidal effects of CuNPs, especially combined with albendazole, which entirely eliminated the parasite after 10-20 min of exposure. The results also showed that although the possible protoscolicidal mechanisms of CuNPs are not clearly understood, the inducing apoptosis through caspases is one of the main protoscolicidal mechanisms of CuNPs. However, supplementary studies, especially in animal models and clinical settings, are needed to approve these results.

The High Potential of Ozone Gas to Inactivate Echinococcus granulosus Protoscoleces During Hydatid Cyst Surgery.

BACKGROUND: In medicine, ozone therapy is effectively used in a broad spectrum of diseases. Reviews have shown that ozone gas demonstrates potent antimicrobial effects against a wide range of pathogenic microorganisms, such as oral bacteria, fungi, viruses, and parasite even in resistant strains. The present investigation was designed to assess the protoscolicidal effects of ozone gas on hydatid cysts protoscoleces in vitro and in vivo. METHODS: Hydatid cyst protoscoleces were acquired from sheep livers that were slaughtered at Kerman slaughterhouse, Iran. The viability of protoscoleces was assessed by the eosin exclusion examination after exposure with ozone gas for 1 to 14 min in vitro and ex vivo. RESULTS: In this study, in vitro assay showed that ozone gas at the concentration of 20 mg/L killed 85 and 100% of hydatid cyst protoscoleces after 4 and 6 min of treatment, respectively. However, in the ex vivo analysis, a longer time was needed to confirm a potent protoscolicidal activity such that ozone gas after an exposure time of 12 min, 100% of the protoscoleces were killed within the hydatid cyst. CONCLUSION: In conclusion, the findings of the present study showed that ozone gas at low concentrations (20 mg/L) and short times (4-6 min) might be used as a novel protoscolicidal drug for use in hydatid cyst surgery. However, more clinical surveys are required to discover the precise biological activity of ozone gas in animal and human subjects.

In vitro evaluation on the scolicidal effect of Myrtus communis L. and Tripleurospermum disciforme L. methanolic extracts.

Hydatid disease, a zoonotic disease, is still endemic in many developing countries that is caused by the metacestode of Echinococcus (E.) granulosus. Surgical management is one of the best choices for the treatment of the hydatidosis and using effective scolicidal agents during hydatid surgery is essential to prevent the secondary infection. The aim of the present in vitro study was to evaluate the scolicidal effect of the methanolic extract of Myrtus communis and Tripleurospermum disciforme against protoscoleces of hydatid cyst. Protoscoleces of E. granulosus were aspirated aseptically from infected livers. Various concentrations of M. communis and T. disciforme extracts at different exposure times were examined for their scolicidal activity. Normal saline and silver nitrate were used as negative and positive groups, correspondingly. The viability of protoscoleces was evaluated by 0.1% eosin. The result of the current study indicated that the highest scolicidal effect (100%) of M. communis was obtained at 100 and 50 mg/ml concentrations and LC50 in 10, 20 and 30 min were 11.64 mg/ml, 7.62 mg/ml, and 6.47 mg/ml respectively. The scolicidal activity of T. disciforme was negligible even at high concentration. The findings have shown that the scolicidal activity of M. communis against echinococcosis protoscoleces was strong, while the T. disciforme extract showed fewer effects. However, further studies are required for identification of the active ingredients in the extract and its safety on cells in effective concentrations.

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.

Unique precipitation and exocytosis of a calcium salt of myo-inositol hexakisphosphate in larval Echinococcus granulosus.

The ubiquitous intracellular molecule myo-inositol hexakisphosphate (IP6) is present extracellularly in the hydatid cyst wall (HCW) of the parasitic cestode Echinococcus granulosus. This study shows that extracellular IP6 is present as its solid calcium salt, in the form of deposits that are observed, at the ultrastructural level, as naturally electron dense granules some tens of nanometers in diameter. The presence of a calcium salt of IP6 in these structures was determined by two different electron microscopy techniques: (i) the analysis of the spatial distribution of phosphorus and calcium in the outer, acellular layer of the HCW (the laminated layer, LL) through electron energy loss spectroscopy, and (ii) the observation, by transmission electron microscopy, of HCW that were selectively depleted of IP6 by treatment with EGTA or phytase, an enzyme that catalyses the dephosphorylation of IP6. The deposits of the IP6-Ca(II) salt are also observed inside membrane vesicles in cells of the germinal layer (the inner, cellular layer of the HCW), indicating that IP6 precipitates with calcium within a cellular vesicular compartment and is then secreted to the LL. Thus, much as in plants (that produce vesicular IP6 deposits), the existence of transporters for IP6 or its precursors in internal membranes is needed to explain the compound's cellular localisation in E. granulosus.