Dextran Sulphate of Sodium-induced colitis in mice: antihyperalgesic effects of ethanolic extract of Citrus reticulata and potential damage to the central nervous system.

Citrus species are widely related to antihyperalgesic and anti-inflammatory effects. The aim of this study was to investigate if treatment with ethanolic extract from peels of mature Citrus reticulata Blanco causes antihyperalgesic effects on the referred mechanical hyperalgesia in a model of dextran sulphate of sodium (DSS)-induced colitis in mice, as well as the possible oxidative damage in different regions of the brain induced by its inflammatory reaction. Antihyperalgesia (30 to 300 mg/kg) was investigated by behavioral response (frequency of response to von Frey filament stimulation) in Swiss mice, while damage to central nervous system was investigated through techniques that evaluated oxidative stress using male black C57 BL6 mice (n=8). Treatment of the animals with the extract (100 mg/kg) from days 3 to 5 after colitis induction reduced referred the mechanical hyperalgesia (32.6 ± 5.1) in relation to the control group (57.4 ± 2.0). Levels of lipid peroxidation or carbonyl proteins were augmented in colitis-induced animals in relation to the disease group. These results indicated an antihyperalgesic effect of the studied extract and a potential impairment of the central nervous system functioning caused by inflammation during colitis, which could be related to mental disorders observed in patients suffering of this pathology.