Efecto in vitro del extracto acuoso de Dichrostachys cinerea (L.) Wight & Arn. en el desarrollo de las fases exógenas de estrongílidos gastrointestinales de ovinos In vitro effect of the aqueous extract of Dichrostachys cinerea (L.) Wight &Arn. on the development of exogenous stages of gastrointestinal strongyles in sheep

The in vitro effect of aqueous extract of leaves from Dichrostachys cinerea on egg hatching, larval development and migration of third-stage larvae of gastrointestinal strongyles, was evaluated. The treatments were three concentrations of aqueous extracts of D. cinerea leaves (500, 250 and 125 mg/mL), albendazole and levamisole solutions, as well as Phosphate Buffer Saline (PBS) and dimethyl sulfoxide (DMSO) as controls; the design was completely randomized. The hatching percentages showed significant differences among post-treatments. PBS caused the highest hatching rate (96,68%); 30,51% hatched with albendazole and the D. cinerea leaf extracts showed moderate hatching rates (between 49,75 and 66,54%), seemingly dose-dependent. The development of L 1 /L 2 larvae to L 3 treated with aqueous D. cinerea extract also showed dose-dependent effects and significant differences with regards to the positive and negative control groups. The dose of 500 mg/mL inhibited larval development in similar percentages as those of albendazole (8,89 and 1,28%, respectively). The PBS medium did not interfere in the larval migration capacity, while with levamisole the values were reduced from 86,45 to 93,92%; the aqueous extracts also significantly reduced such migration, with values between 77,67% and 48,97%. The aqueous D. cinerea extracts showed in vitro anthelmintic activity in the three development stages of the exogenous cycle of gastrointestinal strongyles in sheep; this activity was more evident in the larval development and migration of these nematodes.