In vitro wound healing and cytotoxic activity of the gel and whole-leaf materials from selected aloe species

Ethnopharmacological relevance: Aloe vera is one of the most important medicinal plants in the world with applications in the cosmetic industry and also in the tonic or health drink product market. Different parts of Aloe ferox and Aloe marlothii are used as traditional medicines for different applications. Although wound healing has been shown for certain aloe gel materials (e.g. A. vera ) previously, there are conflicting reports on this medicinal application of aloe leaf gel materials.

Aim of the study: The present study aimed at determining the wound healing properties of the gel and whole-leaf materials of Aloe vera, Aloe ferox and Aloe marlothii, as well as their cytotoxic effects on normal human keratinocyte cells (HaCaT).

Materials and methods: Nuclear magnetic resonance spectroscopy was used to chemically fingerprint the aloe gel and whole-leaf materials by identifying characteristic marker molecules of aloe gel and whole-leaf materials. An MTT assay was performed to determine the cytotoxicity of the various aloe whole-leaf and gel materials on HaCaT cells. Wound healing and in vitro cell migration were investigated with HaCaT cells by means of the CytoSelect™ assay kit.

Results: The in vitro wound healing assay suggested that all the aloe gel and whole-leaf materials examined, exhibited faster wound healing activity than the untreated control group. After 48h, all the aloe gel and whole-leaf materials almost completely caused full wound closure, displaying 98.07% (A. marlothii whole-leaf), 98.00% (A. vera gel), 97.20% (A. marlothii gel), 96.00% (A. vera whole-leaf), 94.00% (A. ferox gel) and 81.30% (A. ferox whole-leaf) wound closure, respectively. It was noteworthy that the gel materials of all the three aloe species exhibited significantly faster (p<0.05) wound healing actions when compared to their respective whole-leaf materials at 32h.

Conclusion: The gel and whole-leaf materials of A. vera, A. ferox and A. marlothii have shown the ability to heal wounds at a faster rate and to a larger extent than untreated keratinocytes. The MTT assay results suggested that the gel and whole-leaf materials of all the selected Aloe species showed negligible toxicity towards the HaCaT cells.