LL-37 antimicrobial peptide: Molecular characterisation and its role in oral health and disease-A narrative review.

BACKGROUND: Antimicrobial peptides are integral components of the innate immune system and play a vital role in maintaining oral homeostasis. LL-37, the only human cathelicidin antimicrobial peptide, has gained increasing attention due to its broad-spectrum antimicrobial activity and diverse immunomodulatory functions within the oral cavity. OBJECTIVE: This narrative review aims to characterise the molecular structure, biological functions, and clinical relevance of LL-37 in oral health and disease. MATERIALS AND METHODS: A comprehensive literature search was conducted using electronic databases, including PubMed, Scopus, and Google Scholar, to identify relevant in vitro, in vivo, and clinical studies evaluating the expression, mechanisms of action, and pathological implications of LL-37 in oral tissues. RESULTS: LL-37 is expressed by various oral tissues, including the gingival epithelium, salivary glands, and inflammatory cells, contributing to host defence against microbial challenges. In addition to its direct antimicrobial effects, LL-37 modulates inflammatory responses, promotes wound healing, and influences cellular proliferation and angiogenesis. Altered expression of LL-37 has been associated with the pathogenesis of several oral diseases, such as periodontitis, dental caries, endodontic infections, and oral squamous cell carcinoma. CONCLUSION: LL-37 plays a multifaceted role in oral immunity by integrating antimicrobial, immunomodulatory, and tissue-regenerative functions. Enhanced understanding of its molecular characterisation and biological activities may support the development of LL-37 as a diagnostic biomarker and a potential therapeutic target in oral pathology.