In vitro protoscolicidal effects of lithocholic acid on protoscoleces of Echinococcus granulosus and its mechanism

Exp Parasitol. 2022 Aug:239:108280. doi: 10.1016/j.exppara.2022.108280. Epub 2022 May 18.

Abstract

Surgery has been found to be the best choice of treatment for hydatidosis. However, leakage of cyst contents during surgery is the foremost reason for recurrence of hydatidosis. In this study, we investigated the in vitro efficacy of lithocholic acid (LCA) against Echinococcus granulosus protoscoleces. The protoscoleces were divided into a control group, an albendazole (ABZ) positive control group and LCA intervention groups at concentrations of 0.5, 1, 2, and 3 mmol/L and stained with 0.1% eosin for observation using an inverted microscope; the protoscolecal ultrastructure was examined with SEM and TEM; the activities of ROS, SOD, and caspase-3 were investigated using an ROS kit, SOD kit, and caspase-3 kit, respectively; the contents of HO-1 and NQO-1 were analyzed by enzyme-linked immunosorbent assay; and the expression level of cytochrome c (Ctyc) was analyzed by western blotting. Results: As the concentration of LCA increased, the survival rate of protoscoleces gradually decreased. The microstructure shows that the external shape and internal structure were gradually deformed and collapse. SOD, GSH, HO-1 and NQO-1 decreased more significantly in the 3 mmol/L LCA group. However, ROS levels gradually increased. LCA treatment for 3 days at all concentrations significantly increased caspase-3 activity and expression in a dose-dependent manner. LCA decreased the level of Ctyc protein in vitro. LCA demonstrated a parasiticidal effect on the protoscoleces of Echinococcus granulosus in vitro. LCA may induce apoptosis of E. granulosus protoscoleces by oxidative stress and mitochondrial pathways.

Keywords: Caspase-3; Ctyc; Echinococcus granulosus protoscoleces; Lithocholic acid; ROS.

MeSH terms

  • Animals
  • Caspase 3 / metabolism
  • Echinococcosis* / drug therapy
  • Echinococcus granulosus*
  • Lithocholic Acid / metabolism
  • Lithocholic Acid / pharmacology
  • Reactive Oxygen Species / metabolism
  • Superoxide Dismutase / metabolism

Substances

  • Reactive Oxygen Species
  • Lithocholic Acid
  • Superoxide Dismutase
  • Caspase 3