The application potential of Nisin in the medical field

Nisin is a small-molecule antimicrobial peptide produced by Streptococcus lactis. It has the advantages of safety, non-toxicity, and excellent bacteriostatic effect, showing great application potential in the medical field, as follows:

Antibacterial Therapy: Nisin has a strong inhibitory effect on Gram-positive bacteria such as some species of Staphylococcus, Streptococcus, and Lactobacillus. It also exhibits antibacterial activity against multidrug-resistant bacteria, including methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, and Enterococcus. Its mechanism of action is similar to that of cationic surfactants: it can bind to bacterial cell membranes and form permeable pores, leading to the loss of intracellular substances and the autolysis of bacterial cells.

Application in Stomatology: Nisin can inhibit various bacteria associated with dental caries, such as Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus acidophilus. Studies have found that it and sodium fluoride have a synergistic inhibitory effect on the growth, acid production, acid resistance, and biofilm formation of Streptococcus mutans, making it promising for the development of new oral antibacterial products, such as mouthwash and chewing gum.

Antitumor Effect: Researchers from the University of Michigan found that high-purity Nisin can kill 70% to 80% of head and neck tumor cells in animal experiments. It may exert antitumor effects by inducing tumor cell apoptosis, arresting the cell cycle, and inhibiting cell proliferation. Additionally, it can synergize with traditional chemotherapeutic drugs such as doxorubicin to enhance the potential of anticancer therapy.

Immunomodulation: Scientists speculate that Nisin may have the ability to activate the host immune response, helping the body fight bacterial infections on its own. Like host defense peptides, it has immunomodulatory effects, but the specific immunomodulatory mechanism requires further in-depth research.

Treatment of Ulcerative Colitis: Researchers from the Tehran Central Branch of Islamic Azad University in Iran prepared chitosan nanogels loaded with Nisin. This Nisin-loaded nanogel has a therapeutic effect on acetic acid-induced ulcerative colitis in rat models, reducing macroscopic colon damage, promoting epithelial cell regeneration, reducing inflammatory cells, increasing goblet cells, and alleviating crypt damage. Its mechanism of action may be related to the regulation of cytokine levels.

Anti-biofilm Activity: Nisin has the property of disrupting biofilms and can be used to prevent and treat infections caused by bacterial biofilms. Studies have shown that Nisin-loaded solid lipid nanoparticles (SLN-Nisin) are more effective than free Nisin in inhibiting the growth of the oral pathogen Porphyromonas gingivalis and disrupting oral biofilms.