Figure 2.

Microdilution Assay of niacinamide and its analogs against S. aureus. Niacinamide shows significant amplification of LL37 potency, and this synergy is present at reduced levels with N-methylnicotinamide, whereas no significant synergy was observed with isonicotinamide. Key: CC = culture control (no treatment), NIA = niacinamide, MeNAM = N-methylnicotinamide, ISON = isonicotinamide, LL37 = cathelicidin antimicrobial peptide (AMP), used at 2 microgram per ml concentration. Data is from two independent repeat experiments, each comprising two replicates. Error bars are SE of mean. The symbols ^∗ and ^∗∗ correspond to p < 0.05 (one-tailed t-test).