In vitro Activities of Pfaffia glomerata Root Extract,Its Hydrolyzed Fractions and Pfaffic Acid Against Trypanosoma cruzi Trypomastigotes

This article reports on the in vitro activity of the hydroalcoholic extract of Pfaffia glomerata roots, its hydrolyzed fractions, and pfaffic acid against Trypanosoma cruzi. The hydroalcoholic extract obtained from dried, milled P. glomerata roots was submitted to acid hydrolysis followed by partition with CHCl₃. The concentrated CHCl₃ fraction was suspended in MeOH/H₂O and partitioned with hexane (F1), CHCl₃ (F2), and AcOEt (F3), in this sequence. The trypanocidal activity of the hydrolyzed extract and its fractions was evaluated in vitro. The hydroalcoholic extract displayed low activity, but fraction F1 was active against trypomastigotes of the Y strain of T. cruzi, with IC₅₀ = 47.89 μg/ml. The steroids campesterol (7.7%), stigmasterol (18.7%), β‐sitosterol (16.8%), Δ⁷‐stigmastenol (4.6%), and Δ⁷‐spinasterol (7.5%) were the major constituents of F1, along with fatty acid esters (7.6%) and eight aliphatic hydrocarbons (30.1%). Fractions F2 and F3 exhibited moderate activity, and pfaffic acid, one of the main chemical constituents of these fractions, displayed IC₅₀ = 44.78 μm (21.06 μg/ml). On the other hand, the hydroalcoholic extract of P. glomerata roots, which is rich in pfaffosides, was inactive. Therefore, the main aglycone of pfaffosides, pfaffic acid, is much more active against trypomastigotes of the Y strain of T. cruzi than its corresponding glycosides and should be further investigated.