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

Abstract

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. Theethanolic and aqueous extraction of plant leaveswas 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. Thephytochemical 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 ± 0.085mg of gallic acid equivalent per g of extract (GAE/g E) and 16.5 ± 0.004mg of quercetin equivalent per g (QE/g E) for the ethanolic extract, and 36.5 ± 0.016mg GAE/g E and 18.2 ± 0.023mg QE/g E for the aqueous extract, respectively. Furthermore, ethanolic and aqueous extracts of M. communis gave a value of IC50 = 0.009 ± 0.0004mg/ml and IC50 = 0.012 ± 0.0003mg/ml for theantioxidant activity, respectively. The in vitro scolicidal activity with concentrations of 50, 75, 100, and 150mg/ml was tested for 5, 10, 15, and 30min, and 5, 10, 15, 30, 60, 90, and 120min for ethanolic and aqueous extracts, respectively. The mortality rate of protoscoleces at concentrations of 100 and 150mg/ml was 98.8 and 100%, respectively, after 5min of exposure to the ethanolic extract, while this rate was 100% at the same concentrations only after 60min of exposure to theaqueous extract. The ethanolic extract showed a stronger scolicidal activity against E. granulosus s.l protoscoleces than the aqueous extract. In the future, otherinvestigations 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.