Deep skin wound healing potential of lavender essential oil and licorice extract in a nanoemulsion form: Biochemical, histopathological and gene expression evidences

Abstract

Cutaneous wound healing is one of the public health interests. This study aimed to investigate the effects of nanoemulsion cream containing lavender essential oil and licorice extract on the healing of deep skin wound in a rat model. Eighty-five male Wistar rats were randomly divided into five groups including untreated defects as negative control and defects treated with vehicle ointment, lavender essential oil and licorice extract in emulsion and nanoemulsion forms, and phenytoin 1 as the positive control with an excisional wound on the dorsal neck of each rat. On days 2, 7 and 14 oxidative stress factors were evaluated in wound tissue homogenates. The expression of transforming growth factor-beta (TGF-beta), and type I and type III collagen genes were evaluated. Also, wound tissue samples were processed for Hematoxylin Sr Eosin and Masson-Trichrome staining. Nanoemulsion reduced the wound area more than other groups significantly. Real-time PCR data demonstrated that nanoemulsion and phenytoin groups have shown the best result in increasing TGF-beta 1, Type I and type III collagen genes expression compared to the other groups. Reduction in lipid peroxidation level and increasing in SOD and GPx activity was also significant in the nanoemulsion and phenytoin groups. The formation of granular tissue likewise the appearance of collagen in nanoemulsion and phenytoin groups were faster than the other groups. Nanoemulsion cream containing lavender essential oil and licorice extract exhibited a promising wound healing potential towards the excisional wound model in rats.