Licochalcone A induces morphological and biochemical alterations in Schistosoma mansoni adult worms.

This paper is the first report on the in vitro effects of licochalcone A, a chalcone isolated from Glycyrrhiza inflate Batalin (Leguminosae), on Schistosoma mansoni adult worms. In vitro, licochalcone A afforded lethal concentrations for 50% of parasites (LC50) of 9.12±1.1 and 9.52±0.9µM against female and male adult worms, respectively, at 24h. Additionally, the compound reduced the total number of S. mansoni eggs and affected the development of eggs produced by S. mansoni adult worms. Together, the results achieved after 24h showed that licochalcone A was 55.7- and 53.3-fold more toxic to S. mansoni female and male adult worms than to Chinese hamster ovary fibroblasts cells, respectively. Treatment with licochalcone A elicited drastic changes in the tegument of S. mansoni adult worms, as well as mitochondrial alteration and chromatin condensation. Licochalcone A also increased the superoxide anion level and decreased the superoxide dismutase activity in S. mansoni adult worms. Overall, our results indicated that licochalcone A displays in vitro schistosomicidal activity. This effect may result from increased production of reactive oxygen species (ROS) induced by the action of licochalcone A. The resulting ROS could act on the S. mansoni tegument and membranes and help induce the death of S. mansoni adult worms.

Schistosomicidal evaluation of flavonoids from two species of Styrax against Schistosoma mansoni adult worms.

CONTEXT: Schistosomiasis is a major health problem worldwide. Thus, the search for new schistosomicidal agents from natural sources can provide prototypes for drug discovery. OBJECTIVE: The present study investigated the chemical composition of the EtOAc fractions of Styrax pohlii Pohl (Styracaceae) (EF-SP) aerial parts and S. camporum A. DC. leaves (EF-SC), as well as schistosomicidal activities against Schistosoma mansoni adult worms, which have not yet been studied. MATERIALS AND METHODS: The crude ethanol extracts of S. camporum leaves and S. pohlii aerial parts (EE-SC and EE-SP) were partitioned with n-hexane, EtOAc, and n-BuOH. The EtOAc fractions were purified by preparative HPLC. The crude extracts, EtOAc fractions and pure compounds were tested against S. mansoni adult worms in vitro. RESULTS: The purification procedure resulted in the isolation of kaempferol-3-O-(2'',4''-di-O-(E)-p-coumaroyl)-ß-d-glucopyranoside (1), kaempferol-3-O-(2'',6''-di-O-(E)-p-coumaroyl)-ß-d-glucopyranoside (2), quercetin (3), and kaempferol (4). The bioassay results indicated that EE-SC, EF-SC, EF-SP, and compounds 2 and 4 are able to separate coupled S. mansoni adult worms. Additionally, EE-SC, EF-SP, and compound 4 killed the adult schistosomes in vitro at 100 µg/mL and 100 µM. DISCUSSION AND CONCLUSION: This is the first time that the presence of compounds 1-2 in S. pohlii and 3-4 in S. camporum has been reported. Additionally, biological results indicated that S. pohlii and S. camporum have great potential as a source of active compounds.