Phenolic Composition and Wound Healing Potential Assessment of Moroccan Henna (Lawsonia inermis) Aqueous Extracts

The present study aims at valorizing Moroccan Henna (Lawsonia inermis) by developing healing formulations for cosmetic and therapeutic uses. For such a goal, the plant was collected from three locations in southeastern Morocco (Alnif, Tafraoute Sidi Ali and Tazarine). Phytochemical analysis of Henna leaves was performed by determining phenolic compound contents, and flavonoids and tannins in it, through its aqueous extracts. Then, specific formulations were prepared using aqueous extracts of L. inermis to assess their in vivo wound healing potential in Swiss albino mice used as animal models. Results disclosed that phenolic compounds (13.48%), as well as flavonoid (9.25%) and tannin (2.57%) contents are higher in Henna leaf extracts from Alnif, while Tazarine Henna aqueous extract was found to be richer in saponins (0.32%). Exclusion chromatographic analysis on Sephadex G50 gel corroborates the obtained results and shows that Lawsone levels (Henna coloring agent) are higher in Henna collected from Alnif. Aqueous Henna leaf extracts, at a dose of 10% in petroleum jelly, have been assessed for their ability to heal induced burns in mice. Healing monitoring, carried-out with Henna extracts on mice batches and those of two control batches (mice batch treated with petroleum jelly alone and batch treated with petroleum jelly containing 1% (flamazine), showed a great reduction in burnt surface with an accentuated contraction percentage (CP) and complete re-epithelialization duration (CRD) at 21 days in the 3 studied Henna-based formulations. These findings suggest the interest of potential development of Henna-based formulations, as a source of phenolic compounds, for further dermatological, cosmetic and therapeutic applications.