Toxicological effect and biochemical alterations induced by different fractions of <i>Euphorbia royleana </i>latex in freshwater harmful vector snail <i>Lymnaea acuminata</i>

Abstract

Laboratory evaluation was made to assess the molluscicidal activity of different fractions of <i>Euphorbia royleana </i>(Family- Euphorbiaceae) latex obtained through sephadex gel column against freshwater snail <i>Lymnaea </i>(Radix) <i>acuminate </i>Lamarack. This snail is the vector of liver fluke, <i>Fasciola hepatica </i>Linnaeus and <i>Fasciola gigantica </i>Cobbold, which causes

endemic fascioliasis in cattle and livestock. The toxic effect of the different fractions was time dependent and fifth fraction obtained through benzene: ethyl acetate (5 :5) had maximum molluscicidal activity against <i>Lymnaea acuminata. </i>There was a significant negative correlation between LC values and exposure periods thus increase in exposure time, the LC₅₀ value of V fraction of <i>Euphorbia royleana </i>latex was decreased from 14.28 mg/l (24 hr) to 9.28 mg/l (96 hr) against <i>Lymnaea</i> <i>acuminata. </i>After exposure to sub-lethal concentrations of this fraction there were significant time and dose dependent alterations observed in pyruvate, lactate levels, ALAT, AAT, AChE and cytochrome oxidase enzyme activities in different body tissues of <i>Lymnaea acuminata. </i>It is proposed that the fifth fraction of <i>E. royleana </i>latex can be used as a molluscicide for controlling the harmful snail population from aquatic ecosystem without any harm due to their reversible toxic action.