Background:

It was well known that inhibitory effect of corticosteroids on cutaneous wound healing antagonized by the use of topical tretinoin and systemic vitamin A. However, the exact mechanism of this antagonistic interaction is not yet fully known. The aim of this study was to investigate the effects of topical tretinoin and adapalene application on tissue hydroxyproline content in corticosteroid impaired full-thickness wound model.

Material and Methods:

Forty Wistar Albino rats weighing 200-250 g were divided into five equal groups. A circular full-thickness wound was made for each animal with a standard 8-mm punch biopsy on the midline of the back. No treatment was given to group I (control). Methyl cellulose gel was applied to wound topically once a day in group 2 (placebo). Single dose methyl prednisolon acetate (Depo-Medrol®) 4.5 mg was administered subcutaneously in group III (corticosteroid group), IV and V. The wounds of each rats in group IV and group V were treated with tretinoin 0.1% cream and adapalene 0.1 % gel once a day respectively. Any additional treatment was given to rats in group III. The wound of each animal was excised at the end of the experiment (7th day) and tissue hydroxyproline levels were measured by using spectrophotometric method. Erythema and erosion of skin surrounding the wound were noted as a reaction of irritation.

Results:

The mean tissue level of hydroxyproline of the corticosteroid group was significantly lower than all other groups. In group 4 and 5, the mean hydroxyproline tissue levels of the wound were higher when compared with control and placebo groups, and the difference was statistically significant. No any signs of irritant reaction were observed in the treatment group.

Conclusion:

The present study demonstrates that methyl prednisolon acetate significantly decreases the tissue hydroxyproline content of full-thickness wound in rats and topical application of adapalene and tretinoin appreciably reverses this inhibitory effect of corticosteroid.

Keywords: corticosteroid, tretinoin, adapalene, wound healing, hydroxyproline