Efficacy of osthole for Echinococcus granulosus in vitro and Echinococcus multilocularis in vivo

• The efficacy of osthole on echinococcosis was studied with in vitro and in vivo experiments.
• The toxicity of osthole was assessed by in vitro and in vivo experiments.
• Osthole was an effective candidate drug for treatment of echinococcosis with low toxicity.
• The level of IL-4 and the percentage of eosinophil are possible be useful indicators of therapeutic effect for echinococcosis.

Echinococcosis is a zoonotic infection caused by cestode species of the genus Echinococcus; in addition, this zoonosis has long been neglected as a parasitic disease and has limited treatment options. Clinical drugs such as benzimidazole derivatives have limited treatment efficacy. The current study evaluated a novel drug, osthole, with low toxicity and high activity against Echinococcus in vitro and in vivo. The results in vitro indicated that the viability of Echinococcus granulosus protoscoleces in the group treated with osthole (120 μM) decreased by 100% within 3 days. In vivo experiments were conducted using parasite-infected mice. For this purpose, three groups of infected mice were treated daily for 6 weeks with albendazole (ABZ, 100 mg/kg, positive control group), osthole (100 mg/kg, experimental group), or honey/PBS (100 mg/kg, negative control group), respectively. The osthole- and ABZ-treated groups presented a significant reduction in wet weight of metacestodes, increase in the level of interleukin (IL)-4 and the percentage of eosinophils compared with the control group. Osthole exhibited a high activity against echinococcosis in vivo. In addition, the toxicity of osthole was evaluated via an in vitro 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, as well as via morphological observation and calculation of liver and kidney function indexes in vivo. No obvious toxic effects of osthole were observed in our study. Therefore, this novel drug may be a promising alternative to benzimidazole in anti-echinococcosis chemotherapy.