RESUMEN
OBJECTIVES: The aim of the study was to investigate the anti-inflammatory, antioxidant and antinociceptive actions of PFPe, a polysaccharide fraction isolated from the dried fruit of the Passiflora edulis. METHODS: Animals were pretreated with PFPe (0.3, 1 or 3 mg/kg, i.p.) 1 h before induction of paw oedema by carrageenan, histamine, serotonin, compound 48/80 or prostaglandin E2 (PGE2). Neutrophil migration and vascular permeability were measured after carrageenan injection into the peritoneum, and the action of the PFPe on the tumour necrosis factor-alpha, interleukin-1 beta (IL-1ß), myeloperoxidase (MPO), glutathione (GSH) and malondialdehyde (MDA) levels was also evaluated. To assay nociception, we examined acetic acid-induced writhing, formalin-induced paw licking and response latency in the hot plate test. KEY FINDINGS: Pretreatment with PFPe significantly inhibited carrageenan-induced paw oedema. PFPe also reduced paw oedema induced by compound 48/80, histamine, serotonin, and PGE2 and compound 48/80-induced vascular permeability. In addition, PFPe significantly reduced the MPO activity, MDA and GSH concentrations, and IL-1ß level. In the nociception tests, PFPe reduced acetic acid-induced writhing and formalin-induced paw licking and did not increase the response latency time. CONCLUSIONS: Our results suggest that PFPe administration reduces the inflammatory response by modulation of the liberation or synthesis of histamine and serotonin, by reduction of neutrophil migration, IL-1ß levels, and oxidative stress and nociception.