Comparative study of the anthelmintic activity of ethanolic and aqueous extracts of Atriplex halimus, the anti-echinococcal plant used in Algeria.

Cystic echinococcosis (CE) remains a major human public health problem in Algeria. Surgical treatment is the gold standard. However, one of the most critical complications of surgery is a recurrence of the disease, which is attributed to the dissemination of protoscoleces during the operation. This study aimed to compare the scolicidal effect of two ethanolic and aqueous extracts of Atriplex halimus, a plant used by the Algerian population against CE. The comparison involved the assessment of the phytochemical content, making screening using GC-MS/MS, and the evaluation of the antioxidant activity using DPPH and the in vitro scolicidal effect of A. halimus extracts. The aqueous and ethanolic extracts of leaves contained 19.601 ± 0.016 and 15.406 ± 0.003 mg of gallic acid equivalent per g of extract (GAE/g extract) of total phenolic. However, the flavonoid content in ethanolic and aqueous extracts was 4.350 ± 0.023 and 1.995 ± 0.026 mg of quercetin equivalent per g (QE/g extract), respectively. Four compounds were identified by GC-MS/MS for the ethanolic extract, while twenty-three compounds were determined for the aqueous extract. The ethanolic and aqueous extracts of A. halimus demonstrated an antioxidant activity with IC50 = 0.850 ± 0.026 mg/ml and IC50 = 0.897 ± 0.060 mg/ml, respectively. The higher in vitro scolicidal effect was 100% after 90 min and 10 min at 100 and 150 mg/ml, respectively for the ethanolic extract and after 120 and 60 min at 100 and 150 mg/ml, respectively for the aqueous extract. Atriplex halimus could be used as a natural source for the production of a potential scolicidal agent for use during CE surgery and/or percutaneous interventions.

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.

Molecular Mechanisms of Endothelialitis in SARS-CoV-2 Infection: Evidence for VE-Cadherin Cleavage by ACE2.

Long COVID-19 syndrome appears after Severe Acute Respiratory Syndrome-Corona Virus (SARS-CoV-2) infection with acute damage to microcapillaries, microthrombi, and endothelialitis. However, the mechanisms involved in these processes remain to be elucidated. All blood vessels are lined with a monolayer of endothelial cells called vascular endothelium, which provides a the major function is to prevent coagulation. A component of endothelial cell junctions is VE-cadherin, which is responsible for maintaining the integrity of the vessels through homophilic interactions of its Ca++-dependent adhesive extracellular domain. Here we provide the first evidence that VE-cadherin is a target in vitro for ACE2 cleavage because its extracellular domain (hrVE-ED) contains two amino acid sequences for ACE2 substrate recognition at the positions 256P-F257 and 321PMKP-325L. Indeed, incubation of hrVE-ED with the active ectopeptidase hrACE2 for 16 hrs in the presence of 10 µM ZnCl2 showed a dose-dependent (from 0.2 ng/µL to 2 ng/µL) decrease of the VE-cadherin immunoreactive band. In vivo, in the blood from patients having severe COVID-19 we detected a circulating form of ACE2 with an apparent molecular mass of 70 kDa, which was barely detectable in patients with mild COVID-19. Of importance, in the patients with severe COVID-19 disease, the presence of three soluble fragments of VE-cadherin (70, 62, 54 kDa) were detected using the antiEC1 antibody while only the 54 kDa fragment was present in patients with mild disease. Altogether, these data clearly support a role for ACE2 to cleave VE-cadherin, which leads to potential biomarkers of SARS-CoV-2 infection related with the vascular disease in "Long COVID-19".