Zizania latifolia is a perennial herb belonging to the family
Gramineae that has been used as a health food in Asian countries.
In this study, we investigated the antimicrobial effect of
Z. latifolia, which increased human beta-defensin 2 (hBD2)
expression in HaCaT cells. hBD2 expression was further increased
in cells treated with Z. latifolia extracts and subsequently
infected with Staphylococcus aureus. Inversely, S.
aureus infection decreased after treatment. The induction
of hBD2 in HaCaT cells was mediated by the Toll-like receptor
2 (TLR2) signaling pathway, including the activation
of extracellular signal-regulated kinase (ERK) and activator
protein 1 (AP-1). Further study using siRNA revealed that
hBD2 played an important role in the inhibition of S. aureus
infection in HaCaT cells. Our data suggest that Z. latifolia
extracts can be used as an antimicrobial ingredient for skin
treatment formulas.