Anti-inflammatory activity of the metabolite extract of Lactobacillus plantarum Su-ls29 on lipopolysaccharide-induced RAW 264.7 macrophage cells

Lactobacillus plantarum Su-ls29 is a native Indonesian probiotic bacteria known to survive high acidity and temperature and possess anti-inflammatory properties. This study aimed to compare the anti-inflammatory activities of the extracellular metabolite extract of L. plantarum Su-ls29 in different growth media and its mechanism in inhibiting pro-inflammatory cytokines. It also profiled the extracellular metabolite compound cultured in skimmed milk and man ragosa sharpe broth. MTT and Griess assays determined the cytotoxicity and nitric oxide production on RAW 264.7 macrophage cells. IL-1β, IL-6, and tumor necrosis factor-alpha production were determined using ELISA, while the metabolites were identified using UHPLC-MS/MS. The interaction between metabolites and pro-inflammatory cytokines was tested in silico. The results showed that L. plantarum Su-ls29-skimmed milk performs optimally in reducing NO production by 1.54 μg/ml compared to Lipopolysaccharide treatment. L. plantarum Su-ls29-skimmed milk metabolite extract was found to inhibit IL-1β production significantly. In this study, 27 metabolites were identified in the metabolite extract of L. plantarum Su-ls29. Based on in silico results, creatine, acetyl-L-carnitine, and L-carnitine showed solid-binding interactions with IL-1β, IL-6, and inducible nitric oxide synthase proteins. It was concluded that the extracellular metabolite of L. plantarum Su-ls29 cultured in skimmed milk exhibited anti-inflammatory activities.