Efficacy of aqueous and methanol extracts of Euphorbia wallichii Hook. f. against larval toxocariasis

Abstract

The ever increasing anthelmintic resistance and low efficacy of conventional anthelmintics against larval toxocariasis has created an interest in evaluating plants as an effective source of anthelmintics. The aqueous and methanol extracts of Euphorbia wallichii were evaluated for efficacy against larvae of Toxocara canis both in vitro and in vivo, using an embryogenesis inhibition assay and a larval recovery assay respectively. In the in vitro study (1000) eggs were treated with 0.5, 1, and 2 mg/mL of plant extracts and the positive control was treated with same dose of albendazole. Crude methanol extract of E. wallichii (LC50 1.09 mg/mL) exhibited higher embryogenesis inhibition compared to its crude aqueous extracts (LC50 1.89 mg/mL). In the in vivo study, embryonated eggs (1000) of Toxocara canis were orally inoculated to wistar rats followed by treatment with crude methanol and aqueous extracts of Euphorbia walliachii at concentrations of 100, 200 and 400 mg/Kg and their liver and lungs were examined for the presence of T. canis larvae on the 7th day post infection (dpi). Maximum efficacy (64.75%) in larval count reduction was recorded for crude methanol extract in liver at dose of 400 mg/Kg in liver. Least efficacy (6.25%) in larval count reduction was recorded for crude aqueous extract E. wallichii at dose of 100 mg/Kg in lungs. The results reveal that Euphorbia walliachii extracts has an antitoxocaral effect and warrants further study as to suitability as an alternative anthelmintic.