The effects of melatonin on the healing of burn wounds in pinealectomized rats

The present study aims to investigate the favorable effects of melatonin on burn wound healing in rats.

In this study, forty Wistar-albino-type male rats were divided into four groups. Group 1 was the control group, Group 2 rats were treated using exogenous melatonin, Group 3 rats were pinealectomized, and Group 4 rats were pinealectomized then treated with exogenous melatonin. In all groups, a deep second-degree burn was created on the backs of the rats with a metal plate heated in boiling water. We monitored the progress of burn healing for seven days. At the end of them, we evaluated hydroxyproline levels, type III collagen, edema, inflammatory infiltration, congestion, vascular proliferation, fibrosis, the thickness of the zone of stasis and the epithelium to assess the progress of healing.

The zone of stasis was less thick in Group 2 than the other groups (p=0.009). Type III collagen dyeing (p=0.031), fibrosis (p=0.011) and edema (p=0.031) were higher in Group 2 than the other groups. Congestion was higher in the control group than Group 4 (p=0.031). Other evaluated parameters showed no significant differences among the groups.

In this study, it was noted that once total melatonin levels exceeded a certain threshold, a preventive effect was exerted on burn wound damage progression by reducing the zone of stasis. Melatonin may also prevent the development of hypertrophic scarring. Melatonin may be a potential therapeutic option that can supplement traditional treatment in burn wounds; however, further studies with higher doses of exogenous melatonin administered over longer periods are needed to further evaluate the effects noted in this study.