20.500.12556/RUL-184877 Gassericins from Lactobacillus paragasseri K7 preparative isolation and discovery of dose-dependent anti-inflammatory effects Gassericins K7 are heterodimeric bacteriocins produced by Lactobacillus paragasseri K7. Their biological characterisation has been limited by challenges in obtaining these compounds in sufficient purity and quantity. In this study, we used a preparative isolation and purification workflow for gassericins K7, combining ammonium sulphate precipitation, Amberlite XAD-16 extraction, and reversed-phase chromatography. Mass spectrometry confirmed the presence of all four peptide components GasK7A α, GasK7A β, GasK7B α, and GasK7B β in the pooled preparation, including GasK7A β, identified here for the first time in natural isolates of this strain. The purified bacteriocin preparation exhibited strong antibacterial activity against indicator strain Latilactobacillus sakei NCDO 2714. Cytotoxicity testing in RAW 264.7 macrophages revealed minimal effects at concentrations up to 50 µg/ml, with only a modest reduction in cell viability observed at 100 µg/ml. Subsequent evaluation of immunomodulatory properties demonstrated a clear dose-dependent anti-inflammatory effect in LPS-stimulated macrophages. Treatment with gassericins K7 reduced nitric oxide (NO) production, downregulated inducible nitric oxide synthase (iNOS) expression, and suppressed secretion of the pro-inflammatory cytokines TNF-α and IL-6. Importantly, exposure of macrophages to gassericins alone did not elicit any inflammatory response. These findings provide the first evidence of anti-inflammatory activity of purified gassericins K7 in eukaryotic immune cells and highlight their potential as postbiotic components or biotherapeutic candidates for inflammatory disorders. The preparative method used in this study enables the production of gassericins K7 in quantities sufficient for advanced in vitro and in vivo investigations, facilitating future development of bacteriocin-based therapeutics. Gassericins K7A Gassericins K7B Lactobacillus paragasseri K7 bacteriocins anti-inflammatory activity purification immunomodulation mikrobiologija bakterije Lactobacillus paragasseri bakteriocini terapevtika protivnetno delovanje odmerki izolacija true false true Angleški jezik Slovenski jezik Članek v reviji 2026-07-16 11:08:31 2026-07-16 11:08:36 2026-07-17 04:30:52 0000-00-00 00:00:00 2026 0 0 Str. 7062–7073 Vol. 18 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579 1867-1306 10.1007/s12602-025-10910-x 268310531 RAZ_Liaqat_Humna_2026.pdf RAZ_Liaqat_Humna_2026.pdf 1 7046F6F89B7FE38A944DBD2DF6FAB8ED d51988f2cea271748aa40b7bc1214f836d7fa89c3ce82127eaef4bbf4c2e3341 ca2fc852-80f5-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=240262 Biotehniška fakulteta 0 0 0