Improvement of skin barrier dysfunction by Scutellaria baicalensis GEOGI extracts through lactic acid fermentation

The development of an alternative medicine to treat atopic dermatitis (AD) from natural sources is necessary.

To improve skin barrier dysfunction by enhancing the differentiation of human keratinocytes with the fermented Scutellaria baicalensis.

Scutellaria baicalensis was fermented with Lactobacillus plantarum and extracted with 70% ethanol (FE). Antioxidant activities and the regulation of the gene expression related to keratinocyte differentiation were measured as well as its proliferation.

This work first proved that the FE had multiple activities, both increasing keratinocyte differentiation and proliferation: The FE greatly up-regulated expression of the genes of keratinocyte differentiation such as involucrin, keratin 10, and transglutaminase-1 (TG-1) up to 4.06-fold, which was 3 times higher than the 2 other extracts. The effect of baicalein on keratinocyte differentiation was also first found; however, its efficacy was lower than that of the fermented extract. The FE proved to effectively accelerate keratinocyte differentiation, rather than to initiate the differentiation, and also showed an ability of stimulating keratinocyte proliferation up to 2.8 × 10⁶ viable cells/mL as well as 70.24 ng/mL of collagen production in fibroblasts. High efficacy of the FE was confirmed by synergistic effects of large amounts of various bioactive substances in the extracts as baicalein alone did not show remarkable effects and even positive controls had not much better activities than the FE.

The fermented extract was able to improve skin barrier dysfunction, and the ointment with 1%-5% (v/v) of the extract be directly used for skin clinical trials to treat AD.