Lactobacillus rhamnosus GG conditioned media modulates acute reactive oxygen species and nitric oxide in J774 murine macrophages

Abstract

Phagocytes such as macrophages are capable of detecting and killing pathogenic bacteria by producing reactive oxygen and nitrogen species. Formation of free radicals in macrophages may be regulated by probiotics or by factors released by probiotics but yet to be identified. Thus, studies were carried out to determine whether cell-free conditioned medium obtained from cultures of Lactobacillus rhamnosus GG (LGG-CM) regulate production of reactive oxygen species (ROS) and/or nitric oxide (NO) in macrophages. J774 macrophages in culture were loaded with either H2DCFDA for monitoring ROS or with DAFFM-DA for NO detection. Free radical production was measured on a fluorescence microplate reader and changes were analysed by Cumulative sum (CuSum) calculations. Low concentration of LGG-CM (10% LGG-CM) or LPS did not cause any significant change in basal levels of ROS or NO production. In contrast, high concentration of LGG-CM (75% and 100%) significantly enhanced ROS generation but also significantly reduced NO level. These findings are novel and suggest for the first time that probiotics may release factors in culture which enhance ROS production and may additionally reduce deleterious effects associated with excessive nitrogen species by suppressing NO level. These events may account, in part, for the beneficial bactericidal and anti-inflammatory actions ascribed to probiotics and may be of clinical relevance.

Food-borne Lactiplantibacillus plantarum protect normal intestinal cells against inflammation by modulating reactive oxygen species and IL-23/IL-17 axis

“…Faculty of Bioscience and Technology for Food, Agriculture and Environment, University of Teramo, Teramo, Italy. * email: acorsetti@unite.it www.nature.com/scientificreports/ Moreover, it has been found that probiotic bacteria can reduce or even block inflammatory signalling via ROS modulation 13,15 , and some in vivo studies indicate that ingestion of probiotic LAB strains significantly modulates the oxidative stress and related inflammatory damage 7,16,17 , even though the mechanisms behind these beneficial effects are not entirely understood.…”

“…Beside human-derived probiotics, food-associated microbes, especially related to fermented foods, have recently recovered scientific interest for their potential health-promoting effects 12 . Previous in vitro studies have shown that Lactobacillus strains can modulate both oxidative stress and pro-and anti-inflammatory cytokines release 13,14 . In this context, we should recall that a redox protective effect has been recently ascribed to Lacticaseibacillus casei Shirota on the cellular damages induced by an oxidative stressor in an in vitro model of enterocytes 14 .…”

Two-step production of anti-inflammatory soluble factor by Lactobacillus reuteri CRL 1098

“…Research reports revealed that certain extracellular peptides produced by probiotic bacteria are responsible for some of their beneficial effects [ 21 – 22 ]. In these works, culture supernatant containing the functional peptides is used, not the purified peptides, despite the fact that its amino acid sequence is available [ 21 – 25 ].…”

Proteomic analysis of microbial induced redox-dependent intestinal signaling

“…Several lactobacilli strains, which are naturally occurring members of the microbiota and commonly used probiotics, have been shown to generate and/or induce reactive oxygen species (ROS) production [24] , [36] , [37] . We reported that certain strains of lactobacilli, in particular Lactobacillus rhamnosus GG (LGG) can induce rapid, and non-microbicidal generation of ROS within colonic epithelial cells [20] .…”

“…We reported that certain strains of lactobacilli, in particular Lactobacillus rhamnosus GG (LGG) can induce rapid, and non-microbicidal generation of ROS within colonic epithelial cells [20] . This evolutionarily conserved generation of ROS mediates cell signaling responses in mammalian cultured cells, in invertebrate models, and in the murine model [17] , [18] , [22] , [24] , [25] , [3] , [36] , [37] , [39] , [41] , [42] . ROS were initially described as functioning in the bactericidal responses of neutrophils, where high levels of ROS are generated by the catalytic activity of the NADPH oxidase (Nox) enzymes, Nox2/gp120phox, also known as ‘respiratory burst’ [23] .…”