Antiparasitic effects of Zingiber officinale (Ginger) extract against Toxoplasma gondii

Zingiber officinale Roscoe, Ginger, has been used in folk medicine as a medicinal plant, as well as a spice and food in many countries. This research was carried out to evaluate the antiparasitic effect of ginger root extract (GE) and GE/F1 (fraction 1 obtained from GE) against Toxoplasma gondii (T. gondii) in vitro and in vivo. The effects of GE and GE/F1 against the proliferation of T. gondii-infected C6 cells and T. gondii were evaluated by several indicators such as an MTT assay, nuclear staining, immunofluorescence staining, apoptotic proteins and animal testing. GE/F1 strongly inhibited the proliferation of T. gondii-infected C6 cells and T. gondii in a dose-dependent manner compared with sulfadiazine. After T. gondii invasion, C6 cells induced the activation of caspase-3, bax, p53 and p21 related to programmed cell death, and GE/F1 effectively suppressed the expression of caspase-3, bax, p53 and p21 causing cell death of the infected host cells. In addition, INF-γ, and IL-8 levels, and the viability of T. gondii-infected mice treated with GE/F1 (500 μg/ml) were not changed or increased during the period of the experiment. These results demonstrate that GE/F1 not only induces anti-T. gondii effects causing the inactivation of apoptotic proteins in infected host cells through the direct inhibition of T. gondii but also has antiparasitic properties which inhibit inflammatory cytokine secretion in vivo.