Pharmacological activities of Asclepias curassavica L. (Apocynaceae) aerial parts

Abstract

Ethnopharmacological relevanceAsclepias curassavica L. (Apocynaceae) is a perennial shrub used in the folk treatment of parasitism, pain, and inflammation. Aim of the studyThis work assessed the antiparasitic, anti-inflammatory, antinociceptive, and sedative effects of an ethanol extract from the aerial parts of Asclepias curassavica (ACE). Materials and methodsThe antiparasitic activity against Trichomonas vaginalis was evaluated using the trypan blue exclusion test. The in vitro anti-inflammatory actions of ACE (1–200 μg/ml) were analyzed using LPS-stimulated primary murine macrophages. The in vivo pharmacological activity of ACE (50–200 mg/kg p.o.) was evaluated using animal models of inflammation (TPA-induced ear edema test and carrageenan-induced paw edema test) and nociception (acetic acid-induced writhing test, formalin-induced licking test, and hot plate test). ResultsACE showed poor antiparasitic effects against Trichomonas vaginalis (IC50 = 302 μg/ml). ACE increased the production of IL-10 in both in vitro assays (EC50 = 3.2 pg/ml) and in vivo assays (ED50 = 111 mg/kg). ACE showed good antinociceptive actions (ED50 = 158 mg/kg in phase 1 and ED50 = 83 mg/kg in phase 2) in the formalin test. Pre-treatment with naloxone blocked the antinociceptive response induced by ACE. In addition, ACE did not induce sedative effects or motor coordination deficits in mice. ConclusionFindings showed that the anti-inflammatory activity of ACE is associated with increasing levels of IL-10 in both in vitro and in vivo assays, whereas the antinociceptive effect is associated with the participation of the opioidergic system, without inducing sedation or motor coordination impairment.