Barley (Hordeum vulgare) is a major crop that is commonly consumed in Korea and abroad. Barley sprouts are more nutritious than conventional barley and are known to have significant health benefits. In this study, we femented the hot water extract of barley sprout (BS) with Lactobacillus plantarum KCL005(P) and Lueconostoc mesenteroides KCL007(M) to confirm the changes in the total phenolic and flavonoid contents, as well as antioxidant activity and immunomodulatory effects in RAW 264.7 cells. The total phenolic and flavonoid content increased in both BSP and BSM. The DPPH radical scavenging activity was increased by 59.93% in BSP and 47.09% in BSM, and the ABTS radical scavenging activity was increased by 65.70% in BSP and 57.09% in BSM. When the BS fermentation product was used to treat RAW 264.7 cells, it was observed that nitric oxide production increased in a dose-dependent manner, and mRNA gene expression of iNOS, COX-2, TNF-α, IL-1β, and IL-6 also increased in the same manner. These results suggest that BS fermented with probiotics may be useful as a potential antioxidant and immunomodulatory functional food for enhancing health.

IntroductionStaphylococcus aureus is a gram-positive bacterium present on the skin and in the digestive tract of humans, and acts as an opportunistic pathogen that causes various diseases such as food poisoning, atopic dermatitis, and pneumonia, which may be fatal in serious cases [1][2][3]. At present, the long-term use of antibiotics has resulted in the development of antibiotic-resistant S. aureus strains that are associated with various clinical issues such as treatment failure and transmission of antibiotics resistance [4,5]. Furthermore, S. aureus forms biofilms which may confer antibiotic resistance, making infections with these strains even more difficult to treat [6].A biofilm is a collection of bacterial polymeric compounds, typically consisting of proteins, extracellular DNA, and polysaccharides, which adhere together and to a specific surface [7]. Biofilm-forming bacteria show higher resistance to antibiotics than that of planktonic bacteria, resulting in chronic or re-infection [8]. Biofilms are produced when bacteria cannot withstand the external environment, such as in the presence of antibiotics or immune cells [9]. In infections with S. aureus, biofilms protect the bacteria from white blood cells and antibiotics [10]. This change in state is regulated by a special mechanism called quorum sensing (QS) [11]. QS involves cellto-cell signaling, and S. aureus QS is controlled by the agr system, which directly or indirectly regulates the S. aureus biofilm-related metabolism and the generation of virulence factors, thereby contributing to infection related to biofilm formation [12,13]. QS is a key process in the development of S. aureus infections, and the agr system is used as a modulator [14]. agr increases the production of many virulence factors and decreases the production of colonization factor, subsequently increasing the viability of S. aureus in poor environmental conditions [15,16]. The agr operon is activated by SarA [17]. The phosphorylation of agrA induces the transcription of RNAIII, and the transcription of the two divergent genes RNAII and RNAIII is activated by the promoters P2 and P3, respectively [7,18,19]. Most virulence genes regulated by RNAIII are additionally regulatedThe spread of antibiotic-resistant strains of Staphylococcus aureus, a gram-positive opportunistic pathogen, has increased due to the frequent use of antibiotics. Inhibition of the quorum-sensing systems of biofilm-producing strains using plant extracts represents an efficient approach for controlling infections. Torilis japonica is a medicinal herb showing various bioactivities; however, no studies have reported the anti-biofilm effects of T. japonica extracts against drug-resistant S. aureus. In this study, we evaluated the inhibitory effects of T. japonica ethanol extract (TJE) on biofilm production in methicillin-sensitive S. aureus (MSSA) KCTC 1927, methicillin-resistant S. aureus (MRSA) KCCM 40510, and MRSA KCCM 40511. Biofilm assays showed that TJE could inhibit biofilm formation in all strains. Furthermore, ...