ABSTRACT
Dengue fever and schistosomiasis are major public health issues for which vector control using larvicide and molluscicide substances present in plants provides a promising strategy. This study evaluated the potential toxicity of the extract of hydroethanol Schinopsis brasiliensis Engl., Anacardiaceae, stem bark and its chloroform, hexane, ethyl acetate, and hydromethanol fractions against Artemia salina and Aedes Aegypti larvae and snails Biomphalaria glabrata. All of the assays were performed in triplicate and the mean mortality rates were used to determine the LC50 and LC90 values using the probit method. The hydroethanol hydromethanol extract and fraction were free of toxicity towards A. salina (LC50 > 1000 µg/ml), while chloroform fraction was moderately toxic (LC50 313 µg/ml); ethyl acetate and hexane fractions displayed low toxicity, with LC50 557 and 582 µg/ml, respectively. Chloroform, hexane, and ethyl acetate fractions showed larvicidal potential towards A. aegypti (LC50 values of 345, 527 and 583 µg/ml, respectively), while chloroform and ethyl acetate fractions were highly toxic to B. glabrata (LC90 values of 68 and 73 µg/ml, respectively). Based on these findings, ethyl acetate, chloroform, and hexane fractions should be further investigated for their potential use against the vectors of dengue and schistosomiasis.
ABSTRACT
Combretum duarteanum Cambess, Combretaceae, is a plant widely distributed in Northeastern Brazil and, in folk medicine, stems and leaves are used for pain treatment. We investigated the antinociceptive effects of the hexanic extract of leaves from C. duarteanum and of friedelin, its main compound, in formalin-, glutamate- and capsaicin- induced orofacial nociception models. In order to isolate friedelin from the hexanic extract, flash chromatography technique was used. Male mice (n = 8/group) were pretreated with hexanic extract, friedelin, morphine or vehicle, before the injection of algogen agents into the right upper lip (perinasal area). The test of formalin-induced orofacial nociception showed that hexanic extract and friedelin significantly reduced nociception (p < 0.001) in both phases of testing. In the glutamate and capsaicin-induced orofacial nociception tests, pre-treatment with hexanic extract produced a significant reduction of orofacial nociception (p < 0.001) at all doses tested.The results suggest the hexanic extract and friedelin possess antinociceptive effects in models of orofacial nociception in rodents.