Determination of the lethal doses LD50 and LD90 of Euphorbia splendens var. hislopii latex on Physa cubensis Pfeiffer

Abstract

The genus Physa are among the most common and widespread fresh-water snails and are frequently associated with the genus Lymnaea and Biomphalaria, typically occupying the same habitat and being hosts of trematodes that can cause disease in humans. Several studies have evaluated the control of snails through the use of plant-derived molluscicides; however, few such studies exist regarding the genus Physa. Determining the correct lethal doses of [latex of Euphorbia splendens] is important for the control of the Physa cubensis snail. In one experimental model, 150 snails from Jacarepaguá, Rio de Janeiro, RJ were used. After acclimatization for 72 hours, the snails were divided into groups of 10 and placed into beakers containing different doses, each at a temperature of 26±1ºC and a relative humidity of 80±10%. The results demonstrated LD 50 of 1.08 µL/L and LD 90 of 3.41 µL/L, without significant changes in the physical or chemical parameters of the solutions. We conclude that E. splendens latex had a significant effect on P. cubensis in the laboratory setting.

Antigiardial Effect of Kramecyne in Experimental Giardiasis

“…In addition, the same assay was performed using the P-I strain of Giardia and a modified variant resistant to albendazole P-I(r); both incubated each concentration used for kramecyne but instead with albendazole (0, 20, 40, 80, 160, and 320 μ g/mL), the test was carried out under the same conditions of time and temperature and the harvest and count was carried out in the same manner as mentioned above. Each count was performed in triplicate and LD 50 value was determined [ 17 ].…”