Ethanolic extract of the aerial parts of Passiflora cincinnata Mast. (Passifloraceae) reduces nociceptive and inflammatory events in mice

Abstract

Background: Passiflora cincinnata Mast. is described as a native species from the Caatinga biome, and used by traditional medicine for several pharmacological purposes, such as inflammatory disorders. However, studies that prove its biological activities are scarce.

Hypothesis/purpose: This paper aims to evaluate the antinociceptive and anti-inflammatory activities of the aerial parts of Passiflora cincinnata (Pc-EtOH) in mice.

Methods: The chemical composition of Pc-EtOH was assessed by high-performance liquid chromatography coupled to diode array detector (HPLC-DAD). The antinociceptive profile of the extract (given orally: 100, 200 and 400 mg/kg) was established using the in vivo chemical models (acetic acid-induced abdominal constriction and formalin-induced paw licking test) and thermal (hot plate test) of nociception. The role of opioid, potassium channels, TRPV-1, muscarinic, serotoninergic (5-HT₃) receptors and the participation of the nitric oxide pathway also was determined. The rota-rod test was used to verify the possible interference of the extract treatment in motor performance. Paw edema induced by carrageenan or histamine, and leukocyte migration, determination of total protein and nitric oxide to the peritoneal cavity were used for anti-inflammatory profile.

Results: The presence of flavonoids in the extract was confirmed using HPLC-DAD. At all doses tested the Pc-EtOH significantly reduced the number of writhing and decreased the paw licking time in both phases of the formalin test (p < 0.05). In the hot plate test, the extract increased the reaction time, reducing painful behavior. The antinociceptive mechanism probably involves central and peripheral pathways, involving the pathway of opioid and muscarinic receptors with influence of potassium channels and the nitric oxide pathway. However, the motor coordination test indicated that in the time of 120 min the extract decreases the stay time of the animal in the rota-rod. Pc-EtOH inhibited significantly (p < 0.05) the increase of the edema volume after administration of carrageenan and histamine. In the peritonitis test, acute pre-treatment with Pc-EtOH inhibited leukocyte migration, with a reduction in the number of neutrophils and concentration of total proteins and nitric oxide.

Conclusion: The present study suggests that Pc-EtOH possesses peripheral and central antinociceptive action, and showed potential in inhibition of release of mediators of the inflammatory process.

Keywords: Anti-inflammatory activity; Antinociceptive activity; Mechanisms of antinociception; Passiflora; Passifloraceae.