In vitro schistosomicidal activity of hydnocarpin D isolated from Vellozia variabillis

Schistosomiasis is a neglected tropical disease that infects over 200million people worldwide and it is caused by schistosomes (parasitic trematodes) [1,2]. Its treatment relies only on Praziquantel, a drug which shows toxic side effects, lack of effectiveness against young worms and it may be less useful in the future due to the drug-resistance of schistosomes. Thus, alternative drugs for the treatment are required [3]. The crude ethanolic stem extract from Vellozia variabillis (Velloziaceae) has shown in vitro schistosomicidal activity against adult worms of Schistosoma mansoni. Further, the flavolignan hydnocarpin D was isolated from stem extract by chromatographic fractionation and preparative HPLC; identified by ¹H- NMR, ¹³C -NMR, and mass spectrometry methods and also evaluated in vitro against S. mansoni. Adult worms of S. mansoni LE strain were recovered from the mesenteric veins of the infected mice and cultured in 24-well plates at 37 °C in RPMI1640 media [4]. Hydnocarpin D was dissolved in 10% DMSO and diluted into the medium to give 12.5, 25, 50, 100 and 200µM. Adult worms were kept for 72 hours and the viability was monitored every 24hours. As negative control were used adult worms treated with 10% DMSO. The biological assay has shown that Hydnocarpin D caused the death of the S. mansoni adult worms (100% at 200 and 100µM, and 75% at 50µM after 48hours; 100% at 25µM after 72 hours) and reduced the motor activity significantly of 100% of the adult worms (25, 50, 100, 200µM after 24hours and at 12.5µM after 72 hours). It was also registered a partial tegument alteration at 50, 100 and 200µM. Hydnocarpin D showed good results and can be a good choice to futures studies for the seeking of alternative drugs to schistosomiasis treatment.

Acknowledgements: To FAPESP (Process 2014/08404 – 6) and CNPq for financial support.

Keywords: Schistosoma mansoni, hydnocarpin D, Vellozia variabillis.

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