Efficacy of Zingiber officinale ethanol extract on the viability, embryogenesis and infectivity of Toxocara canis eggs.

Abstract

This study evaluated the effect of Zingiber officinale (Z. officinale) ethanol extract on the viability, embryogenesis and infectivity Toxocara canis (T. canis) eggs. It was carried out both in vitro and in vivo. In the in vitro experiment, unembryonated T. canis eggs were incubated with 25, 50 and 100mg/mL Z. officinale extract at 25°C for 6, 12, and 24h to assess the effect of Z. officinale on their viability and for two weeks to assess the effect of Z. officinale on their embryogenesis. In vivo experiment was performed to assess the effect of Z. officinale on infectivity of T. canis eggs. Treated embryonated eggs by Z. officinale extract at concentrations of 25, 50 and 100mg/mL for 24h were inoculated into mice and their livers were examined for the presence of T. canis larvae on the 7thday after infection and for histopathological evaluation at 14thday post-infection. Z. officinale showed a significant ovicidal activity on T. canis eggs. The best effect was observed with 100mg/mL concentration after 24h with an efficacy of 98.2%. However, the treated eggs by 25, 50mg/mL of Z. officinale extract after 24h showed ovicidal activity by 59.22 and 82.5% respectively. Moreover, this extract effectively inhibited T. canis eggs embryogenesis by 99.64% and caused their degeneration at the concentration of 100mg/mL after 2weeks of treatment. However, the lower concentrations, 25 and 50mg/mL inhibited embryogenesis by 51.19 and 78.57% respectively. The effect of Z. officinale on the infectivity T. canis eggs was proven by the reduction of larvae recovery in the livers by 35.9, 62.8 and 89.5% in mice groups inoculated by Z. officinale treated eggs at concentrations of 25, 50 and 100mg/mL respectively. Histopathologically, the liver tissues of mice infected with Z. officinale treated eggs at the concentration of 100mg/mL appeared healthy with slight degenerative changes of hepatocytes, opposite to that recorded in the infected mice with treated eggs by the lower concentrations. In conclusion; Z. officinale extract possessed dose-dependent anti-T. canis activity on the viability, embryogenesis and infectivity of T. canis eggs.