Efeitos de uma dieta rica em gordura e de uma droga anti-inflamatória não-esteróide sobre a cicatrização cutânea de ratos Wistar propensos e resistentes a obesidade

Abstract

Overweight induced by high-fat diet delays wound healing through elongation of inflammatory phase, however, when receiving an obesogenic diet, some rats are susceptible to eveloping the overweight phenotype, whereas others are resistant. Nonsteroidal antiinflammatory drugs are frequently used to reduce the inflammation. This study investigated cutaneous wound healing in diet-induced obesity (DIO)-prone and diet-resistant (DR) rats and evaluated the contribution of celecoxib administration on cutaneous wound healing of these animals. Male rats were fed with a standard (Control, C) or high-saturated fat (30%) diet. After 19 weeks, experimental group was subdivided into DIO and DR groups. An excisional lesion was made and the animals were killed 7 or 14 days later. Treated groups received a daily dose of celecoxib 5 or 10 mg/kg/day from two days before wounding until 7 days after wounding when were killer. The body weight was higher in the DIO group compared to the C and DR groups. Retroperitoneal fat was higher in the DIO group than in the C and DR groups and was higher in the DR group than in the C group. Celecoxib-treatment did not alter the higher body weight presented by DIO group or higher retroperitoneal fat percentage displayed by DIO and DR groups. All groups treated with celecoxib 10 mg showed delayed wound healing, and weren´t further analysed. The DIO group presented glucose intolerance, and both the DIO and DR groups presented delayed wound contraction and re-epithelialisation. The celecoxib 5 mg-treatment reversed the glucose intolerance in the DIO group and the delayed contraction in the DIO and DR groups. Compared to the DR group, the DIO group displayed higher amounts of inflammatory cells as well as higher levels of lipid peroxidation. Celecoxib-treatment (5 mg) did not reduce the number of PMN, but reduce mast cells number in DIO group and macrophages number and lipid peroxidation in both groups. Myofibroblastic differentiation and vessel remodeling were delayed in both the DIO and DR groups. The celecoxib 5 mg-treatment increased the myofibroblastic differentiation, but did not alter the blood vessels. Hydroxyproline levels were similar in the DIO and DR groups. The celecoxib 5 mg-treatment increased the hydroxyproline levels in all groups. Nitrite levels were lower in the DIO group than in the DR group. TNF-α expression was increased in the DIO group compared to the DR group. Our results showed that DIO as well as DR rats present delays in cutaneous wound healing due mainly to intense inflammation, and a lowdose of celecoxib accelerates cutaneous repair in these conditions.