Investigation of the effect of ibuprofen on wound healing in experimental Staphylococcus aureus soft tissue infections

Abstract

Soft tissue infections (STIs) occur as a result of the colonization of pathogenic bacteria upon the destruction of normal skin microbial flora and the skin integrity. Streptococci and staphylococci are the most frequent causes of bacterial STIs. Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen are often used in STIs because of their analgesic and antipyretic effects. However, evidence suggests that these drugs might delay both epithelization and angiogenesis in the early phases of wound healing because of an antiproliferative effect. The aim of this study was to investigate the effect of ibuprofen on the wound healing in STIs caused by Staphylococcus aureus in immunosuppressed mice. A total of 120 female Balb/c mice were used in the study and the mice were assigned to four test groups and two control groups. The test groups were defined as follows; B (Bacteria group, n= 23), Bl (Bacteria + Ibuprofen group, n= 23), BA (Bacteria + Ampicillin group, n= 23), BIA (Bacteria + Ampicillin + Ibuprofen group, n= 21); and the control groups were defined as follows; S1B2 (only immunosuppressed controls, n= 15) and S2B2 (Sham group). Immunosupression was induced with cyclophosphamide and the experimental infection was generated by subcutaneous inoculation of bacterial suspension (2 x 108 cfu/ml) of methicillin-sensitive S.aureus ATCC 25923 to the right hind leg. Ibuprofen was given to the mice by gastric gavage (50 mg/kg/day), and ampicillin (100 mg/kg/day) by intramuscular injection. Wound sizes that appear in the animals were measured on a daily basis. Serum and tissue (epithelial tissue, connective tissue, sebaceous glands, sweat glands) samples were obtained on the first, third and seventh days. The tissue samples were examined histopathologically by hematoxylin-eosin (HE) staining method and IL-1, IL-6, TNF-? and VECF (Vascular Endothelial Growth Factor) levels were determined in serum samples by ELISA method. The tissue cytokine reactions were also evaluated by immunohistochemical (immunoperoxidase staining) method in tissue samples. In our study, no significant change was detected in the wound sizes of B and Bl groups from the second day to the end of study period (p> 0.05). On the other hand the wound dimensions of BA and BIA groups gradually decreased and remained superficial. The average serum levels of TNF-? and IL-1 was detected low in all groups. The mean value of serum IL-6 on the first day in group B was determined to be higher compared to other groups, and when this difference was compared to groups Bl and BA, and the control group, it was found statistically significant (p< 0.05). In addition, the VEGF levels which were detected low in all groups in the third day of infection increased significantly at the seventh day. The results of histopathologic and immunohistochemical studies have supported the results of ELISA and yielded similar results with serum cytokine patterns. In conclusion, our data indicated that ibuprofen has no negative effect on the wound healing in soft-tissue infections caused by S.aureus.