Impact of sildenafil-containing ointment on wound healing in healthy and experimental diabetic rats.

Abstract

The study evaluated the effect of different concentrations of sildenafil-containing ointment on wound healing in healthy and streptozotocin (STZ)-induced diabetic rats. A total of 108 Sprague Dawley male rats aged 5months were randomly divided into two groups: healthy and diabetes-inducing rats. Following induction of diabetes by intraperitoneal STZ injection (55mg/kg), diabetic and healthy rats were subdivided into six groups (9 rats each). Linear incisions of the dorsal backs of rats were made. Then, rats were treated twice daily with either 2%, 2% + Fucidin, 5% sildenafil-containing ointments, oral sildenafil (13.0mg/kg), moist exposed burn ointment or vehicle. During treatment, the percent reduction of the wound area and tensile strength were measured on days 3, 7 and 10. Furthermore, histopathology was performed on the wounded skin on similar days for the assessment of collagen synthesis and proliferation of new capillary vessels. In healthy and STZ-induced diabetic rats, the percent reduction in wound area on day 3 was significantly higher in sildenafil-containing ointment-treated groups than all other groups, whereas on day 7 only the 5% sildenafil-containing ointment-treated group showed better response in healthy rats. Although the sildenafil-containing ointment significantly showed better tensile strength than all other groups, the 5% sildenafil-treated group significantly enhanced the tensile better than the 2% and 2% + Fucidin dose. Furthermore, the histological evaluation revealed that sildenafil-containing ointment promoted collagen synthesis and proliferation of new capillary vessels. Our results suggest that sildenafil-containing ointment can provide an advantage in wound healing by promoting wound contractions and resistance to wound breakage in healthy and diabetic conditions. Therefore, 5% sildenafil-containing ointment can be used as a support factor for wound healing in healthy and diabetic conditions; however, clinical trials are required to confirm the benefits of sildenafil in wound healing.