Novel phospholipase A2 inhibitors from python serum are potent peptide antibiotics

Area of Science:

• Biochemistry
• Microbiology
• Pharmacology

Background:

• Antimicrobial peptides (AMPs) are crucial in combating drug-resistant bacteria.
• The need for novel antimicrobial agents is driven by increasing bacterial resistance.
• Serum proteins from Python reticulatus are a potential source of novel AMPs.

Purpose of the Study:

• To synthesize and evaluate AMPs derived from Python reticulatus serum for antimicrobial activity.
• To assess the efficacy of selected AMPs in promoting wound healing.
• To investigate the safety profile of these AMPs regarding hemolytic and cytotoxic effects.

Main Methods:

• Eight synthetic AMPs were tested for bactericidal activity against Gram-positive and Gram-negative bacteria using disc diffusion and micro-broth dilution methods.
• Minimum inhibitory concentrations (MICs) were determined for potent AMPs.
• Wound healing activity was evaluated in a mouse model infected with Staphylococcus aureus, and mechanisms were explored via Western blot analysis.

Main Results:

• Four AMPs, including PIP-18[59-76], showed potent dose-dependent bactericidal activity against tested pathogens, particularly Staphylococcus aureus.
• PIP-18[59-76] exhibited superior antimicrobial activity compared to standard antibiotics.
• Topical application of PIP-18[59-76] and β-Asp65-PIP[59-67] accelerated wound healing in mice, modulating NF-kB pathways with low hemolytic and cytotoxic effects.

Conclusions:

• Python reticulatus-derived AMPs, especially PIP-18[59-76], possess significant antimicrobial and wound-healing properties.
• These AMPs demonstrate potential as therapeutic agents against bacterial infections and for wound management.
• The study highlights the low toxicity of these peptides on human cells, supporting their further development.