Topical application of Cinnamomum hydroethanolic extract improves wound healing by enhancing re-epithelialization and keratin biosynthesis in streptozotocin-induced diabetic mice

Abstract

Context: Cinnamomum verum J. Presl. (Lauraceae) has a high number of polyphenols with insulin-like activity, increases glucose utilization in animal muscle, and might be beneficial for diabetic patients.

Objective: This study evaluated the effectiveness of an ointment prepared from Cinnamomum verum hydroethanolic extract on wound healing in diabetic mice.

Materials and methods: A total of 54 male BALB/c mice were divided into three groups: (1) diabetic non-treated group mice that were treated with soft yellow paraffin, (2 and 3) mice that were treated with 5 and 10% C. verum. Two circular full-thickness excisional wounds were created in each mouse, and the trial lasted for 16 d following induction of the wound. Further evaluation was made on the wound contraction ratio, histopathology parameters and mRNA levels of cyclin D1, insulin-like growth factor 1 (IGF-1), glucose transporter-1 (GLUT-1), total antioxidant capacity, and malondialdehyde of granulation tissue contents. HPLC apparatus was utilized to identify the compounds.

Results: The HPLC data for cinnamon hydroethanolic extract identified cinnamaldehyde (11.26%) and 2-hydroxyl cinnamaldehyde (6.7%) as the major components. A significant increase was observed in wound contraction ratio, fibroblast proliferation, collagen deposition, re-epithelialization and keratin biosynthesis in the C. verum-treated groups in comparison to the diabetic non-treated group (p < 0.05). The expression level of cyclin D1, IGF1, GLUT 1 and antioxidant capacity increased in the C. verum-treated groups in comparison to the diabetic non-treated group (p < 0.05).

Conclusions: Topical administration of C. verum accelerated wound healing and can possibly be employed in treating the wounds of diabetic patients.

Keywords:

• Antioxidant activity
• cinnamaldehyde
• insulin-like growth factor 1
• glucose transporter-1

Acknowledgements

The authors are grateful to Rasta lab for histopathology and molecular studies, Keivan Razzaghi (Dr) for the preparation of extracts and formulations.

Disclosure statement

No potential conflict of interest was reported by the authors.