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)-β-d-glucopyranoside (1), kaempferol-3-O-(2'',6''-di-O-(E)-p-coumaroyl)-β-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.