PN5

PN5 is an antimicrobial peptide from pine needles (Pinus densiflora) with strong anti-inflammatory and antibacterial activity against multidrug-resistant strains. It neutralizes LPS and inhibits cytokine overexpression, making it a potential therapeutic for sepsis and antibiotic resistance.

- Reduce inflammation and protect against bacterial infections or gut damage

- Support recovery from sepsis or resistant infections

Mechanism of Action

How this peptide works in the body

Membrane Disruption:

PN5 exerts its antimicrobial activity by interacting with negatively charged phospholipids on microbial membranes. This cationic peptide inserts itself into the lipid bilayer, forming transmembrane pores (2.8--4.6 nm in diameter). This leads to ion leakage, loss of membrane potential, and bacterial lysis. This mechanism is particularly effective against Gram-negative and Gram-positive bacteria, fungi, and some enveloped viruses.

Biofilm Inhibition:

PN5 prevents the formation of bacterial biofilms by interfering with quorum sensing molecules such as autoinducer-2 (AI-2), preventing bacterial aggregation and enhancing immune clearance.

Anti-Inflammatory Effects:

PN5 suppresses nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, reducing transcription of proinflammatory cytokines TNF-α, IL-6, and IL-1β. It neutralizes lipopolysaccharides (LPS) by binding the lipid A region, forming stable peptide-LPS complexes that prevent activation of Toll-like receptor 4 (TLR4)on macrophages and dendritic cells, mitigating excessive immune responses.

Stability and Resistance Prevention:

PN5 resists degradation by elastase, a proteolytic enzyme released during inflammation, maintaining its antimicrobial potency in inflamed tissues. Unlike conventional antibiotics, PN5 does not induce bacterial resistance even after prolonged exposure, as it targets membrane integrity rather than intracellular components, minimizing selective pressure for resistant mutations.