The nematocidal activity of an
Oxalis tetraphylla hydroalcoholic extract against the nematode
Haemonchus contortus (
Hc) was assessed in vitro and the major compounds associated with nematocidal activity were identified. One hydroalcoholic extract was obtained from
O. tetraphylla stems and leaves (
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The nematocidal activity of an
Oxalis tetraphylla hydroalcoholic extract against the nematode
Haemonchus contortus (
Hc) was assessed in vitro and the major compounds associated with nematocidal activity were identified. One hydroalcoholic extract was obtained from
O. tetraphylla stems and leaves (
Ot HE-SLE). The in vitro lethal concentrations (LC50 and LC90) against both eggs and exsheathed
Hc infective larvae (L3) were assessed.
Ot HE-SLE showed a potent ovicidal activity (LC50 = 0.213 mg/mL; LC90 = 0.71 mg/mL) and larvicidal effect (LC50 = 28.01 mg/mL; LC90 = 69.3 mg/mL). Later on, the extract was bipartitioned to obtain an ethyl acetate phase (
EtOAc-Ph) and an aqueous phase (
Aq-Ph). Both phases were assessed against
Hc eggs at 0.25 and 1.0 mg/mL concentrations. The results with
EtOAc-Ph showed 93.6% ovicidal activity, while 96.6% was recorded with
Aq-Ph at 48 h post-confrontation (PC). In the case of larvicidal activity, both phases were assessed at 28 mg/mL;
Aq-Ph showed >80% larvicidal activity 24 and 72 h PC, while
EtOAc-Ph did not show important activity. HPLC analysis showed the presence of coumaric acid and flavonols. Flavonol compounds were the major compounds and were associated with the nematocidal activity. Additionally, the
Aq-Ph that showed the highest activity was purified, and the fraction F3 showed the highest nematocidal activity.
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