EVALUATION OF SCHISTOSOMAL ACTIVITY OF CARVACROL IN IN VIVO AND IN IN VITRO EXPERIMENTS

Abstract

The schistosomal activity of carvacrol and carvacrol acetate was studied using Swiss mice weighing about 20g and infected with Schistosoma mansoni cercariae, in in vitro and in vivo experiments, as described in this paper. Two in vitro experiments were performed using 4 or 8?g/mL. For the in vivo experiments, one group of 10 mice was treated orally with 300g/ kg for five consecutive days. Two other groups with 10 mice each were treated orally with single doses of 15 and 30mg/kg respectively. Both compounds proved active, at the 4?g/mL concentration, causing the death of adult S. mansoni worms in less than 24 hours for the in vitro tests. In the in vivo experiments no significant schistosomal activity was observed in the oral treatment with one 15 or 30mg/animal dose of carvacrol or carvacrol acetate or when treated with 300mg/kg during five consecutive days. In the in vivo experiments no significant schistosomal activity was noted considering all the chemotherapy regimens tested. We have, therefore, concluded that the compounds are effective considering in vitro trials, but do not present in vivo activity. These findings suggest that carvacrol and carvacrol acetate should not be considered schistosomicidal agents for clinical testing. It is important to bear in mind that in vitro trials are useful but they are a simulation of reality and one approach does definitely not replace the other.