Antimicrobial and immunomodulatory activity of host defense peptides, clavanins and LL-37, in vitro: An endodontic perspective.
Lima. Stella Maris F SMF; Freire. Mirna S MS; Gomes. Ana Luisa O ALO; Cantuária. Ana Paula C APC; Dutra. Flávia Rodrigues P FRP; Magalhães. Beatriz S BS; Sousa. Maurício Gonçalves C MGC; Migliolo. Ludovico L; Almeida. Jeeser A JA; Franco. Octávio L OL; Rezende. Taia Maria B TMB
Key Findings
- LL‑37 inhibited Enterococcus faecalis at 57 µM (MIC)
- LL‑37 increased IL‑6 and TNF‑α while decreasing IL‑10 and nitric oxide in immune cells
- LL‑37 showed stronger antibacterial activity than clavanin peptides and calcium hydroxide in the tested dental model
Practical Outcomes
- LL‑37 looks promising for fighting dental infections, but it isn’t a ready‑to‑use supplement for general health or longevity. For biohackers, the main takeaway is that LL‑37 has antimicrobial and immune‑modulating effects, yet more research is needed before considering any self‑administration or systemic protocols.
Summary
The study tested the natural peptide LL‑37 against common root‑canal bugs and compared it to a standard dental disinfectant. LL‑37 killed the bacteria at a certain concentration and changed immune signals, showing it works better than the other peptides tested, but the research is limited to dental cells, not whole‑body use.
Abstract
Endodontic treatment is mainly based on root canal disinfection and its failure may be motivated by microbial resistance. Endodontic therapy can be benefitted by host defense peptides (HDPs), which are multifunctional molecules that act against persistent infection and inflammation. This study aimed to evaluate the antimicrobial, cytotoxic and immunomodulatory activity of several HDPs, namely clavanin A, clavanin A modified (MO) and LL-37, compared to intracanal medication Ca(OH)<sub>2</sub>. HDPs and Ca(OH)<sub>2</sub> were evaluated by: (1) antimicrobial assays against Candida albicans and Enterococcus faecalis, (2) cytotoxicity assays and (3) cytokine tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, interleukin (IL)-1α, IL-6, IL-10 and IL-12 and nitric oxide (NO) production by RAW 264.7 cells incubated with or without heat-killed (HK) C. albicans or E. faecalis combined or not with interferon-γ. The minimum inhibitory concentration (MIC) was established only for E. faecalis (LL-37, 57μM). Considering cytotoxicity, clavanin MO was able to reduce cell viability in many groups and demonstrated lowest LC<sub>50</sub>. The Ca(OH)<sub>2</sub> up-regulated the production of MCP-1, TNF-α, IL-12 and IL-6 and down-regulated IL-1α, IL-10 and NO. Clavanins up-regulated the TNF-α and NO and down-regulated IL-10 production. LL-37 demonstrated up-regulation of IL-6 and TNF-α production and down-regulation in IL-10 and NO production. In conclusion, LL-37 demonstrated better antibacterial potential. In addition, Ca(OH)<sub>2</sub> demonstrated a proinflammatory response, while the HDPs modulated the inflammatory response from non-interference with the active cytokines in the osteoclastogenesis process, probably promoting the health of periradicular tissues.
Study Information
pubmed
2017
2017-07-14T00:00:00.000Z
10.1016/j.peptides.2017.07.005
19
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