An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
Saponarin, a flavone from young barley leaves, was shown in lab cell studies to calm down inflammation and allergic reactions and to boost skin‑protective proteins like LL‑37, hyaluronan synthase‑3 and aquaporin‑3. While the work is all in petri dishes, it hints that saponarin‑rich extracts might help skin health and reduce irritation.
Santos. Jaime J; Pallarès. Irantzu I; Ventura. Salvador S
The paper looks at whether our own natural peptide LL‑37 could help stop the protein clumps that damage brain cells in Parkinson's disease. Early lab work suggests LL‑37 can stick to those harmful clumps and might block them from forming, but the research is still at a very basic stage.
de Buhr. Nicole N; Parplys. Ann Christin AC; Schroeder. Maria M; Henneck. Timo T; Schaumburg. Berfin...
The study found that older men with COVID‑19 have more sticky DNA webs (NETs) in their blood, partly because a natural peptide called LL‑37 protects these webs from being broken down. While the body’s DNase enzymes that normally clear NETs are higher in COVID patients, they drop off with age in men, making it harder to clear the webs and raising clot risk.
Scientists attached the natural antimicrobial peptide LL‑37 to tiny gold rods and used near‑infrared light to heat them up, killing bacteria in wounds and helping the skin close faster. The combo was safe in lab tests, stuck to bacteria, and boosted healing, but making the gold‑rod particles and using the right light equipment isn’t something you can do at home yet.
The study found that newborns born early (preterm) have lower levels of the immune peptide LL‑37 in their cord blood, and those with higher LL‑37 were less likely to develop a serious lung problem called bronchopulmonary dysplasia (BPD). Steroid treatment before birth lowered LL‑37, while LL‑37 levels rose with each week of pregnancy.
Engelberg. Yizhaq Y; Ragonis-Bachar. Peleg P; Landau. Meytal M
Scientists studied a short piece of the human antimicrobial peptide LL‑37 and found that swapping one amino‑acid for cysteine lets the pieces form disulfide‑linked pairs that stack into stable fibrils, which changes how well they kill bacteria. The work shows that where the cysteine is placed controls activity and that the structures are sensitive to oxidation‑reduction conditions, explaining why nature avoids such designs.
This paper reviews how stem cells naturally make the antimicrobial peptide LL‑37 (and others) and how that peptide can also affect the stem cells themselves, boosting their growth and movement. It suggests that mixing stem cells with LL‑37 could improve treatments against infections and aid tissue repair, but it doesn’t give specific dosing or protocols for everyday use.
The study shows that the natural antimicrobial peptide LL‑37 (and its mouse version CRAMP) can directly bind to Zika virus particles, break them open, and stop the virus from replicating, which protects mouse testes and sperm from damage. In mice, giving LL‑37 by injection reduced virus levels, suggesting it could be a potential antiviral treatment, but it’s still early‑stage research and not ready for personal use.
Gao. Shuai S; Khan. Abidullah A; Chen. Xuhong X; Xiao. Guohui G; van der Veen. Stijn S; Chen. Yin Y;...
In lab tests, a bacterial molecule called c‑di‑GMP was applied to skin cells and mice before exposing them to MRSA, a tough antibiotic‑resistant bug. The treatment didn’t kill the bacteria directly, but it primed the skin’s immune system, causing a big jump in natural antimicrobial proteins like LL‑37 and other defensins, and attracted more immune cells to the wound. This led to a dramatic drop in bacterial numbers in the mouse wounds.
Syed. Meesum M; Kammala. Ananth K AK; Callahan. Brianna B; Oskeritzian. Carole A CA; Subramanian. Ha...
The study shows that lactic acid, a natural by‑product of glucose metabolism, can calm down mast cells that cause allergic‑type reactions by blocking the MRGPRX2 pathway. This calming effect was seen in lab cells and in mice, and it lowered severe allergy reactions and skin inflammation. The effect depends on the acidity level, so it’s not a simple “take lactate” fix, but it hints that high‑lactate conditions (like after intense exercise) might reduce certain inflammation spikes.
The abstract explains that new blood vessel growth (angiogenesis) is a key part of several chronic skin problems like psoriasis, eczema, rosacea, hives, and hidradenitis. A small protein called LL‑37 can trigger this process, especially in rosacea, by boosting factors like VEGF. Because angiogenesis helps these skin issues get worse, blocking it might be a useful treatment strategy.
The study shows that the antimicrobial peptide LL‑37 can slip into bacterial‑like membranes and make the lipids move faster, which helps explain how it kills bacteria. However, the experiments were done on simple lab‑made vesicles, not human cells, so the findings don’t directly tell you how to use LL‑37 for health or performance.
Jackmann. Natalja N; Englund. Sofia S; Frisk. Per P; Mäkitie. Outi O; Utriainen. Pauliina P; M&...
The study measured the blood level of hCAP-18 (the precursor of the antimicrobial peptide LL-37) in kids and found that low levels signal problems with bone‑marrow blood‑cell production, while high levels show lots of myeloid cells. This could help doctors see how well the marrow is working, especially in blood cancers.
van Harten. Roel M RM; Veldhuizen. Edwin J A EJA; Haagsman. Henk P HP; Scheenstra. Maaike R MR
A study in pig immune cells found that the peptide CATH-2 (and to a lesser extent LL‑37) can calm down inflammation caused by bacterial components, especially in the aggressive M1 type of macrophages, and CATH-2 even works when whole bacteria are present. This shows the peptide has strong anti‑inflammatory properties in a pig model, but it’s not yet clear how it works in humans or how to use it safely.
Balhuizen. Melanie D MD; Versluis. Chantal M CM; van Grondelle. Monica O MO; Veldhuizen. Edwin J A E...
Scientists showed that the human peptide LL‑37 and similar cathelicidins can change how immune cells react to tiny bubbles (outer membrane vesicles) released by a Gram‑negative bacterium, mainly by calming the strong inflammation caused by LPS. The effect varies depending on how the vesicles are prepared, indicating LL‑37 could be used to fine‑tune immune responses, but the work is still early and done only in cell cultures.
Olmos-Ortiz. Andrea A; Hernández-Pérez. Mayra M; Flores-Espinosa. Pilar P; Sedano. Gabriel...
The study shows that when fetal membranes are infected with E. coli, they quickly make the antimicrobial peptide LL‑37 and other defensins, but these defenses aren’t enough to stop the bacteria or tissue damage. Different parts of the membrane release different peptides over time, and mixing several peptides together works better than any single one in lab tests. This tells us that LL‑37 is part of the body’s early response, but on its own it’s not a magic bullet against infection.
A natural skin peptide called p4 (from chemerin) can kill MRSA bacteria and works together with the body’s own antimicrobial peptide LL‑37. In mouse skin tests, applying p4 lowered the amount of MRSA and reduced inflammation, showing it could be a useful skin‑protective agent, though it’s still early‑stage research.
Scientists found that stem cells taken from human umbilical cords release the natural antimicrobial peptide LL‑37, which can stop the formation of harmful bacterial films (biofilms) by Pseudomonas aeruginosa on breathing tubes used for newborns. The amount of LL‑37 goes up as more stem cells are added, but levels level off after a certain cell concentration. This suggests LL‑37 could be useful for fighting stubborn infections, though the study used stem‑cell secretions, not a direct peptide supplement.
The study shows that the way LL‑37 and other antimicrobial peptides stick into cell‑like membranes depends on the length and saturation of the fat molecules in the membrane. Longer, more unsaturated fats let LL‑37 and magainin‑2 get into the membrane more easily and work better, while indolicidin prefers thinner, more fluid membranes. More peptide in the membrane usually means stronger activity, but not always.
Ogawa. Youichi Y; Kinoshita. Manao M; Kawamura. Tatsuyoshi T; Shimada. Shinji S
This review explains that mast cells have internal sensors called TLR3, TLR7, and TLR9 that detect viral genetic material, and that the antimicrobial peptide LL‑37 released by mast cells can change how these sensors work, influencing immune responses.