Abstract
Background: Wound can be defined as disruption of cellular, anatomical, or functional continuity of living tissues. Nicotine causes damage to the epithelial layer of blood vessel and delays wound healing. It plays an important pathogenic role in impaired wound healing. Although in the last millennium, topical use of nicotine has been reported. It promotes collagen synthesis and, in turn, promotes wound healing. The role of topical nicotine on wound healing is controversial. Therefore, it was planned to evaluate and compare wound healing activity of various doses topical nicotine in rats.

Aim and Objectives: The objectives of this study were to evaluate the effect of topical nicotine on wound healing in an excision wound model in rats.

Materials and Methods: For evaluation of the wound healing effects of the nicotine, excision wound model was used. Nicotine was applied topically in a dose of 1.5 g%, 3.0 g%, and 6.0 g% petroleum base. Petroleum jelly served as control for topical nicotine. Dressing done by applying topical nicotine until (20 days) complete wound healing was observed. Parameters evaluated were surface area of wound and percentage closure.

Results: Findings of this show that, on day 4, nicotine 3.0 g% and 6 g% the wound surface area were more as compared to control. On day 12, nicotine 6.0 g% showed significantly more wound surface area than control (P < 0.05). Percentage wound contraction with topical nicotine (6.0 g%) was less as compared to control on day 4, 8, and 12 (P < 0.001). On day 16, percentage wound contracture with topical nicotine (6.0 g%) contraction was significantly less as compared to control (P < 0.05). Although percentage wound contraction with topical nicotine (all preparations) and control was similar on day 20.

Conclusion: Finding shows that topical nicotine impairs wound healing in a dose related pattern during initial stages of healing in an excision wound model. However, there is no delay in wound healing with any dose of topical nicotine.

Key words: Topical Nicotine; Excision Wound Model; Wound Healing Activity