CXCL8 and infection: Next, to determine whether LJLE also suppresses pro-inflammatory cytokine expression by PDLFs after oral bacterial infection, we examined IL-6 and IL-8 expression levels in PDLFs treated with 100 μg/mL LJLE for varying times following infection with well-known periodontal pathogens (P. gingivalis, T. denticola, T. forsythia, and F. nucleatum).