Carpobrotus edulis (L.) N.E.Br. extract as a skin preserving agent: From traditional medicine to scientific validation

Objective: Carpobrotus edulis(L.) N.E.Br. is a succulent perennial plant native to South Africa and growsinvasively in the Mediterranean basin. It is commonly used for the treatment of various diseases, includ-ing skin wound healing and regeneration, for which experimental validation is lacking. We thereforeevaluated the skin healing properties by testing aC. edulisaqueous leaf extract (CAE) on cell culturesand in enzymatic assays.Methods:Micro-morphological analysis of leaves was carried out using scanning electron microscopyand light microscopy. Phytochemical features and antioxidant activity of CAE were evaluated byreversed-phase liquid chromatography coupled with diode array detection and electrospray ion trapmass spectrometry (RP-LC-DAD-ESI-MS), andin vitrocell-free assays. Biological activities were evaluatedusing keratinocytes and fibroblasts, as well as elastase, collagenase, and hyaluronidase.Results:CAE showed high carbohydrates (28.59% ± 0.68%), total phenols ([101.9 ± 6.0] g gallic acid equiv-alents/kg dry extract [DE]), and flavonoids ([545.9 ± 26.0] g rutin equivalents/kg DE). RP-LC-DAD-ESI-MSrevealed the predominant presence of hydroxycinnamic acids (51.96%), followed by tannins (14.82%) andflavonols (11.32%). The extract was not cytotoxic, had a strong and dose-dependent antioxidant activity,and inhibited collagenase (> 90% at 500mg/mL) and hyaluronidase (100% at 1000mg/mL). In cell cultureexperiments, CAE increased wound closure and collagen production, which was consistent with its highpolyphenol content.Conclusion:Our data support the use of theC. edulisfor skin care and the treatment of skin problems.Moreover, use ofC. edulisfor skin care purposes could be an eco-friendly solution to reduce its invasive-ness in the environment.