An antimicrobial peptide of the cathelicidin family that provides innate immune defense by killing pathogens and modulating inflammation and wound healing.
In older women with depression, blood levels of the immune peptide LL‑37 are higher than in non‑depressed peers, and this rise isn’t linked to overall body weight, muscle, or fat—except that more visceral (belly) fat might be tied to higher LL‑37. Overall body composition doesn’t seem to drive LL‑37 levels.
Olekson. Melissa A MA; You. Tao T; Savage. Paul B PB; Leung. Kai P KP
Researchers tested synthetic molecules called ceragenins, which mimic natural antimicrobial peptides like LL‑37, to see if they can break down bacterial biofilms and help wound healing in lab dishes. They found that several ceragenins were better than LL‑37 at killing biofilms and, at low doses, could boost skin cell movement and blood‑vessel formation, though higher doses were toxic to skin cells.
Researchers found that a snake‑venom peptide called crotalicidin (Ctn) can kill the parasite that causes Chagas disease in lab tests, doing so without harming mammalian cells at the tested concentrations. It works by breaking the parasite’s membrane and causing necrotic cell death, and it’s especially effective against the disease‑spreading form of the parasite.
Paparo. L L; Aitoro. R R; Nocerino. R R; Fierro. C C; Bruno. C C; Canani. R Berni RB
A study using human gut cells in the lab found that a fermented milk drink containing Lactobacillus paracasei (FM‑CBAL74) can boost the cells' growth, strengthen the gut lining, and increase production of natural antimicrobial proteins like LL‑37, which help fight infections. However, this was done in cell cultures, not in people, so the results are preliminary for everyday use.
Researchers tested a lab-made peptide called OP-145, which is based on the natural human peptide LL‑37, and found it can kill most of the tested drug‑resistant Staph bacteria and break down the protective slime they form.
Sonesson. Andreas A; Przybyszewska. Kornelia K; Eriksson. Sigrid S; Mörgelin. Matthias M; Kjell...
The study shows that people with atopic dermatitis have Staphylococcus aureus bacteria forming protective biofilms on their skin, and the natural antimicrobial peptide LL‑37 can stick to these biofilms but doesn’t kill the bacteria well because the bacteria release an enzyme called staphopain that chops LL‑37 into harmless pieces. This means LL‑37 alone isn’t enough to fight these infections in AD skin.
Scientists made a human version of the natural antimicrobial peptide LL‑37 and used computer modeling and lab tests to see how it sticks to a bacterial enzyme called PagP. They found that LL‑37 binds tightly to PagP, mainly through certain amino acids, and this binding may block the enzyme’s activity, giving the peptide stronger antibacterial effects.
Guerra. Alberto Daniel AD; Rose. Warren E WE; Hematti. Peiman P; Kao. W John WJ
The study shows that treating stem cells with the antibiotic minocycline turns on a cell‑signaling pathway (NF‑κB) that makes the cells release more IL‑6 and swallow more Staph bacteria, which speeds up wound healing. Interestingly, this also lowers the cells' own production of the antimicrobial peptide LL‑37, yet the overall antibacterial effect improves.
Yamada. Noriaki N; Martin. Lukas B LB; Zechendorf. Elisabeth E; Purvis. Gareth S D GSD; Chiazza. Fau...
In people with severe injury and bleeding, a natural immune peptide called LL‑37 shoots up in the blood. In rats, giving a lab‑made version of this peptide (Pep19‑4LF) after a big blood loss helped keep blood pressure up and protected the kidneys, liver, and lungs from damage. The protection seems to come from calming down inflammation pathways.
The study explains that the antimicrobial peptide LL‑37 is found in high amounts in psoriasis skin and can kick‑start immune cells called dendritic cells, leading to inflammation. This adds to the already known role of the Th17/IL‑23 pathway in driving the disease.
The study shows that the antimicrobial peptide LL‑37 can trigger mast cells in the gums to release inflammatory chemicals, and that a specific form of bacterial lipopolysaccharide from the gum‑pathogen P. gingivalis can block this effect. This suggests LL‑37 isn’t just an antimicrobial; it can also promote inflammation in the mouth, which may worsen gum disease if mast cells are over‑active.
Verjans. Eddy-Tim ET; Zels. Sven S; Luyten. Walter W; Landuyt. Bart B; Schoofs. Liliane L
LL-37 is a natural peptide that helps the immune system, but scientists still don’t fully know how it talks to many different cell receptors. This review gathers what we do know about the ways LL-37 can turn on these receptors, showing that the exact binding tricks are still fuzzy and often indirect.
Medina Santos. Carlos Erik CE; López Hurtado. Carmen Nathaly CN; Rivas Santiago. Bruno B; Gonza...
The study looked at three natural antimicrobial peptides—LL‑37, HNP‑1 and HBD‑2/3—and how they change immune signals in human immune cells and cartilage cells grown in the lab. HBD‑2/3 and HNP‑1 tended to boost inflammatory signals, while LL‑37 lowered a protein (MMP‑1) that can break down joint tissue. The authors think the first two might worsen arthritis, whereas LL‑37 could be protective.
Strömstedt. Adam A AA; Park. Sungkyu S; Burman. Robert R; Göransson. Ulf U
The study shows that plant‑derived cyclotide peptides can kill bacteria, especially Gram‑negative bugs, at very low (sub‑micromolar) concentrations—sometimes even better than the human antimicrobial peptide LL‑37. Their effectiveness depends on how they interact with a specific membrane lipid (phosphatidylethanolamine). This work mainly reveals how these peptides work in the lab, not how to use them in people.
Agak. George W GW; Kao. Stephanie S; Ouyang. Kelsey K; Qin. Min M; Moon. David D; Butt. Ahsan A; Kim...
The study shows that skin‑friendly bacteria (healthy P. acnes strains) trigger immune cells (Th17) that release LL‑37, but LL‑37 alone doesn’t kill the acne‑causing bacteria. Instead, other secreted factors from these immune cells are responsible for the antibacterial effect.
Chen. Xi X; Qi. Guangying G; Qin. Mingqun M; Zou. Yantao Y; Zhong. Kanghua K; Tang. Ying Y; Guo. Yon...
The study shows that the gene that makes the antimicrobial peptide LL‑37 is turned off by DNA methylation in oral cancer cells. When the methyl groups are removed with a drug, the gene becomes more active, suggesting LL‑37 may help suppress tumors. However, the work is done in lab cancer models and uses a powerful chemotherapy‑type drug, so it doesn’t give a direct, safe way for everyday people to boost LL‑37.
Malekkhaiat Häffner. S S; Nyström. L L; Nordström. R R; Xu. Z P ZP; Davoudi. M M; Sch...
Scientists found that tiny layered double‑hydroxide (LDH) particles stick to bacterial‑like membranes better when they’re smaller, and this makes the natural antimicrobial peptide LL‑37 work harder at breaking those membranes. The particles also flip the charge on bacteria and tiny fat bubbles, causing them to clump together, which could help trap or clear microbes. However, the particles alone don’t directly kill the bacteria, and the whole system is still a lab‑stage concept.
Persson. Louise J P LJ; Aanerud. Marianne M; Hardie. Jon A JA; Miodini Nilsen. Roy R; Bakke. Per S P...
In people with COPD, the natural antimicrobial peptide LL‑37 is higher in the lungs and blood compared to healthy folks, rises even more during flare‑ups, and is linked to more inflammation, older age, smoking history, and a higher chance of future flare‑ups and bacterial colonisation.
High blood sugar changes how a natural immune peptide called LL-37 works in immune cells. In normal cells, more sugar lowers LL-37, while in cells infected with TB, more sugar actually raises LL-37 but also lets the bacteria grow more. This suggests that blood sugar control matters for TB risk in diabetics, and LL-37 might become a marker for disease progression, but it’s not ready for any DIY treatment yet.
Miraglia. Erica E; Nylén. Frank F; Johansson. Katarina K; Arnér. Elias E; Cebula. Marcus M...
Researchers found that the cancer drug Entinostat can make cells produce more of the natural antimicrobial peptide LL‑37 by turning on two proteins, STAT3 and HIF‑1α, that control the gene for LL‑37. This was shown in lab cells and confirmed that the effect needs a working STAT3 pathway.