Polysaccharide fraction isolated from Passiflora edulis inhibits the inflammatory response and the oxidative stress in mice.

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.

Sulfated-polysaccharide fraction extracted from red algae Gracilaria birdiae ameliorates trinitrobenzenesulfonic acid-induced colitis in rats.

OBJECTIVES: The aim of this study was to evaluate the protective effect of the sulfated-polysaccharide (PLS) fraction extracted from the seaweed Gracilaria birdiae in rats with trinitrobenzenesulfonic acid (TNBS)-induced colitis. METHODS: In the experiments involving TNBS-induced colitis, rats were pretreated with polysaccharide extracted from G. birdiae (PLS: 30, 60 and 90 mg/kg, 500 µL p.o.) or dexamethasone (control group: 1 mg/kg) once daily for 3 days starting before TNBS instillation (day 1). The rats were killed on the third day, the portion of distal colon was excised and washed with 0.9% saline and pinned onto a wax block for the evaluation of macroscopic scores. Samples of the intestinal tissue were used for histological evaluation and assays for glutathione (GSH) levels, malonyldialdehyde (MDA) concentration, myeloperoxidase (MPO) activity, nitrate and nitrite (NO3 /NO2 ) concentration and cytokines levels. KEY FINDINGS: PLS treatment reduced the macroscopic and microscopic TNBS-induced intestinal damage. Additionally, it avoided the consumption of GSH, decreased pro-inflammatory cytokine levels, MDA and NO3 /NO2 concentrations and diminished the MPO activity. CONCLUSIONS: Our results suggest that the PLS fraction has a protective effect against intestinal damage through mechanisms that involve the inhibition of inflammatory cell infiltration, cytokine releasing and lipid peroxidation.