Sasa veitchii extract mitigates disruption of skin barrier function in a mouse model of dry skin

Sasa extract is a Chinese anti-inflammatory herbal remedy. Its effects on dry skin are unclear. We investigated the potential preventive effects of topical Sasa veitchii extract (SVE) on dry skin. Shaved napes of mice were treated twice daily for 5 days with acetone and diethyl ether followed by water (AEW) to induce dry skin. Treatments consisted of 1 % SVE in Vaseline, 0.5 % SVE in Vaseline, or Vaseline alone applied intermittently. Transepidermal water loss (TEWL) was measured on the day before treatment, on treatment days 2 and 4, and the day after treatment. Skin samples were harvested, fixed, and processed for hematoxylin-eosin staining and immunohistochemistry. TEWL and epidermal thickness increased following AEW treatment but were significantly reduced in a dose-dependent manner in mice treated with SVE. In SVE-treated skin, immunohistochemical analyses revealed increased expression levels of filaggrin, loricrin, and involucrin, proteins that help maintain skin barrier function. Moreover, topical application of SVE induced the expression of occludin and ZO-1, molecules involved in the formation of cutaneous tight junctions. Topical application of SVE may mitigate disruption of barrier function in dry skin by increasing expression levels of skin barrier component proteins. • Topical Sasa veitchii extract normalizes stratum corneum barrier function in dry skin. • Sasa veitchii extract increases expression of tight junction molecules. • Herbal remedy (kampo) topical Sasa veitchii extract ameliorates dry skin.