Efficacy of camellia chrysantha extract in repairing the skin barrier and managing sensitive skin

Summary: Skin barrier dysfunction is a key mechanism underlying sensitive skin (SS), characterized by decreased barrier proteins, loss of hyaluronic acid, and delayed epidermal healing, resulting in clinical symptoms of SS. Therefore, identifying an effective strategy for repairing the skin barrier and improving SS is essential. <i>Camellia chrysantha</i> is a rare medicinal and edible plant, and its extract (CCE) is rich in flavonoids, polyphenols, and polysaccharides, suggesting its potential to promote skin health. This is the first study to report the efficacy of CCE in managing SS. We established a UV-induced HaCaT keratinocyte damage model to evaluate the skin barrier repair effects of CCE. Compared to the model group, the levels of FLG and LOR in the CCE group increased by 1.3-fold and 1.2-fold, respectively (<i>P</i><0.01). Similarly, the effect of CCE on HaCaT cell migration was assessed using a scratch assay. Compared to the control group, the migration rate of cells following CCE intervention increased by 38.99% (<i>P</i><0.001) at 24 h. Moreover, the inhibitory effect of CCE on hyaluronidase was tested to evaluate its skin-soothing efficacy. The IC₅₀ value of CCE was 1.96 mg/mL, comparable to that of vitamin C (1.02 mg/mL). Furthermore, a double-blind, split-face, placebo-controlled clinical trial was conducted, enrolling 30 subjects with SS. An emulsion containing 1% CCE was formulated, and its safety was evaluated through patch testing. Skin parameters were measured using non-invasive instruments, and capsaicin-induced stinging scores were assessed using questionnaires. CCE showed no skin irritation and significantly improved TEWL, erythema, and stinging scores after 28 days of application. These results provide valuable insights into the effects of CCE on skin health, highlighting its beneficial role in skin barrier repair and the improvement of SS. Jianhua Zhang^{1, 2, 3}, Shichao Liu^{1, 2}, Wenjiao Guo^{1, 2, 3}, Jing Deng^{1, 3} 1. N.O.D topia (GuangZhou) Biotechnology Co., Ltd., Guangzhou, Guangdong, China. 2. Simpcare (GuangZhou) Biotechnology Co., Ltd., Guangzhou, Guangdong, China. 3. Guangdong Sensitive Skin Care Engineering Technology Research Center, Guangzhou, Guangdong, China. Epidermal Structure and Barrier Function