In vitro antischistosomal activity of the pimaradienoic acid against Schistosoma mansoni
Pimaradienoic acid (PA) is a pimarane-type diterpene with antispasmodic activity that inhibit the vascular contractility blocking extracellular Ca2+ influx [1,2]. PA was isolated from Viguiera arenaria roots by chromatographic fractionation and in vitro evaluated against Schistosoma mansoni adult worms. Couple adult worms of S. mansoni LE strain were recovered from mesenteric veins of the infected mice and cultured in 24-well plates at 370C in RPMI1640 media . PA was dissolved in 10% DMSO and diluted into the medium to give 10, 25, 50 and 100µM. Coupled adult worms were kept for 5 days and the viability, pairing, egg production, and egg development were monitored every 24hs. As negative control (NCG) were used adult worms treated with 10% of DMSO. Regarding the viability, PA (10, 25, 50 and 100µM) did not cause the death of the S. mansoni adult worms, but it reduced the motor activity. PA (10, 25, and 50µM) significantly decreased the daily egg production by 30.2%, 38.4% and 45.1%, respectively. PA (100µM) was able to both separate the adult worm pairs (into male and female) and decrease 100% of the egg production after 120hs. PA, at the doses of 10, 25, 50 and 100µM, significantly inhibited the egg development by 100%.
Acknowledgements: To FAPESP (Process 06/60142–4, 06/60138–2) for financial support.
References: 1. Ambrosio et al. (2006) Life Sci 79:925–933, 2. Ambrosio et al. (2004) Biochem Syst Ecol 32:221–224, 3. Smithers, Terry (1965) Parasitol 55: 695–700.