A novel antimicrobial peptide AH-12 attenuates mitochondrial response to inflammatory stimuli and prevents periodontitis via antibacterial and anti-inflammatory effects.

Antibiotic-assisted periodontal therapy remains a primary clinical strategy, yet the rising prevalence of bacterial resistance severely compromises its therapeutic efficacy. To address this challenge, antimicrobial peptides (AMPs) have emerged as promising alternatives owing to their distinct antibacterial mechanisms. Here, we developed a novel antimicrobial peptide, AH-12, by systematically optimizing P-113-the minimal inhibitory fragment of human salivary Histatin 5-through N-terminal modification, amidation, and acetylation. In vitro evaluations demonstrated potent inhibitory effects of AH-12 against key oral pathogens (Fusobacterium nucleatum, Porphyromonas gingivalis, and Streptococcus gordonii), achieved via bacterial membrane lysis and suppression of FadA adhesin secretion in F. nucleatum. Beyond its antibacterial properties, AH-12 targeted inflammatory regulation by modulating mitochondrial function. Mitochondria, as early responders to inflammation, drive inflammatory cascades via Ca2+-dependent signaling. Remarkably, AH-12 stabilized mitochondrial Ca2+ levels, thereby attenuating mitochondrial reactive oxygen species (mtROS) overproduction and mitochondrial DNA (mtDNA) release, which collectively contributed to its robust anti-inflammatory effects. In order to minimize the loss of medication during administration and to better fit the shape of the periodontal pockets, a GelMA hydrogel (GelMA@AH-12) was engineered for controlled release applications. In vivo studies validated the outstanding efficacy of GelMA@AH-12, highlighting AH-12 as a transformative candidate for periodontitis treatment.