Defensins
Endogenous antimicrobial peptides; research category.
What it is
Defensins are a family of small (3–5 kDa) cationic antimicrobial peptides produced by neutrophils, epithelial cells, and other components of the innate immune system. The major human defensins are divided into alpha-defensins (HNP-1 through HNP-6) and beta-defensins (HBD-1 through HBD-6).
Defensins represent one of the most ancient antimicrobial defense systems in vertebrates. They have been extensively studied as research compounds and as potential therapeutics for antibiotic-resistant infections, but no specific defensin has reached widespread clinical use.
Mechanism of action
Defensins are amphipathic peptides that disrupt microbial cell membranes through pore formation and other mechanisms. They are active against gram-positive bacteria, gram-negative bacteria, fungi, and some enveloped viruses. Beyond direct antimicrobial activity, defensins have immunomodulatory effects on innate and adaptive immune cell function.
Clinical evidence
Despite extensive preclinical research, defensins as therapeutic agents have faced challenges in clinical translation, including production costs, stability, and pharmacokinetic optimization. No specific defensin is currently in widespread clinical use.
Why we don’t prescribe it at The Tide
Defensins are not currently available as standardized clinical pharmaceuticals appropriate for prescribing. The category remains primarily a research interest. For antimicrobial peptide indications in our practice, LL-37 (cathelicidin) is the preferred option with more established clinical use patterns.
Side effects and contraindications
Limited clinical safety data due to limited clinical use.