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.

Comparative proteome profiling of hydatid fluid from Algerian patients reveals cyst location-related variation in Echinococcus granulosus.

Human cystic echinococcosis, an endemic zoonosis in Algeria, is caused by larvae of the cestode Echinococcus granulosus. Parasitic modulation of the immune response allows E. granulosus to persist in intermediate hosts. Previous in vitro and in vivo immunological studies have shown differences in host immune responses according to the status and location of the hydatid cysts in the body. In this study, a proteomic analysis of human hydatid fluids was performed to identify the proteins in hydatid cyst fluids. Hydatid fluid was obtained after cystic surgical removal from three patients with these cysts. The study was conducted on fertile hydatid fluids from lungs, vertebra, and infertile paravertebral fluids. Comparisons of the protein compositions of these fluids revealed differences in their protein profiles. These differences are probably related to the cyst location and fertility status of the parasite. Notably, our analysis identified new proteins from the parasite and human host. The identification of host proteins in hydatid fluids indicates that the hydatid walls are permeable allowing a high protein exchange rate between the metacestode and the affected tissue. Interestingly, our study also revealed that parasite antigenic protein expression variations reflect the differences observed in host immunostimulation.

Comparative study of nitric oxide (NO) production during human hydatidosis: relationship with cystic fluid fertility.

Human hydatidosis is characterized by a prolonged coexistence of Echinococcus granulosus and its host without effective rejection of the parasite. This parasitic infection constitutes a major health problem in Algeria. In this study, we investigated in vivo production of nitrite (NO(2)(-) + NO(3)(-)) in sera of Algerian patients carrying different cyst locations. Nitrite (NO(2)(-) + NO(3)(-)) levels were evaluated by the Griess method. Our results indicated that the levels of nitrite were significantly higher in the sera of hydatic patients than those of healthy controls supporting the involvement of nitric oxide (NO) in antihydatic action. The levels of nitrite in sera of the patients with hepatic hydatidosis were significantly higher than those with pulmonary infection. The lower serum (NO(2)(-) + NO(3)(-)) levels were observed in the relapsing cases. In addition, (NO(2)(-) + NO(3)(-)) levels of fertile hydatic fluids were significantly higher compared to infertile fluids. Our results suggest that the presence of NO products in hydatic fluids seems to be related to the location and the fertility of hydatic cysts. The assessment of protein concentration in hydatic fluids showed that the concentration of proteins was not exclusively dependent on the fertility but on the cyst locations. The assessment of (NO(2)(-) + NO(3)(-)) production in hydatic patients may be a useful tool to evaluate effector mechanisms of NO and clinical manifestations.

In Vitro Study of Nitric Oxide Metabolites Effects on Human Hydatid of Echinococcus granulosus.

Hydatidosis is characterized by the long-term coexistence of larva Echinococcus granulosus and its host without effective rejection. Previous studies demonstrated nitric oxide (NO) production (in vivo and in vitro) during hydatidosis. In this study, we investigated the direct in vitro effects of NO species: nitrite (NO(2) (-)), nitrate (NO(3) (-)) and peroxynitrite (ONOO(-)) on protoscolices (PSCs) viability and hydatid cyst layers integrity for 24 hours and 48 hours. Our results showed protoscolicidal activity of NO(2) (-) and ONOO(-) 24 hours and 3 hours after treatment with 320 muM and 80 muM respectively. Degenerative effects were observed on germinal and laminated layers. The comparison of the in vitro effects of NO species on the PSCs viability indicated that ONOO(-) is more cytotoxic than NO(2) (-). In contrast, NO(3) (-) has no effect. These results suggest possible involvement of NO(2) (-) and ONOO(-) in antihydatic action and point the efficacy of these metabolites as scolicidal agents.