Antimicrobial Efficacy Of Antimicrobial Peptides From The Skin Of Rana Chensininsis On Wound Infection

Antimicrobial peptides (AMPs) are typically relatively small molecules with broadspectrum antibacterial activity and important for the innate immune response in organisms.Rapidly increasing antibioticresistance represents a serious challenge to human health andmedicine, and there is therefore a clear need to search for new types of therapeutic agents.AMPs are of particular interest as candidates for the development of new antimicrobial agentsdue to their widespread action and low level of associated induced resistance.Temporin-1CEb and chensinin-1are natural AMPs isolated and purified from the skinsecretions of Rana chensinensis. The modified peptides L-K6and chensinin-1b, which aredesigned and synthesized according to the sequence of temporin-1CEb and chensinin-1,exhibit strong inhibitory effect to Gram-positive and Gram-negative bacteria.Wound infection is mainly caused by pathogenic microorganism, the same woundinfection which lead to almost all the mixed infection. The key to prevent and treat woundinfection is to inhibit the bacterial growth on the wound, and making models is quitenecessary in investigation of drugs on wound infection.In this present study,9AMPs, including L-K6and chensinin-1b from the AMP libraryconstructed by our laboratory, were studied on the antimicrobial activity.L-K6andchensinin-1b with the highest antimicrobial potency were used to research the drugpenetration of skin. Then we built a Full-thickness skin excision wound infection model basedon mice to reveal the role of L-K6and chensinin-1b in wound infection. The bacterial strainwere Staphylococcus epidermidis, Staphylococcus aweus, Pseudomonas aeruginosa whichtake a large proportion in wound infection. The results showed that the antimicrobial peptidesL-K6and chensinin-1b decreased the viability of wound infection bacteria. L-K6andchensinin-1b could penetrate into the skin, suggesting that both peptides won’t degrade inthe skin. The results of Full-thickness skin excision wound infection model showed that L-K6and chensinin-1b could close the wound at3-6days, and promote angiogenesis and fibration,Increasing level of hydroxyproline, thus to promote wound healing, suggesting that L-K6andchensinin-1b could be as candidates for the development of new antimicrobial agents againstwound infection.