Biotransformation of whey by Weissella cibaria suppresses 3T3-L1 adipocyte differentiation.

Biotransformation, the structural modification of chemical compounds, has proved to be an indispensable tool in providing beneficial health effects. Although the health benefits of biotransformation using plant sources has been widely studied, the anti-adipogenic effect of biotransformed dairy products, such as whey, have not yet been demonstrated. Here, we investigated the anti-adipogenic effect of whey biotransformed by Weissella cibaria in 3T3-L1 adipocytes. Weissella cibaria-biotransformed whey considerably reduced the accumulation of lipid droplets and intracellular triglycerides in 3T3-L1 cells. In the presence of W. cibaria-biotransformed whey, the mRNA and protein expression of a key transcription factor, peroxisome proliferator-activated receptor γ (PPARγ), for adipogenesis was markedly suppressed in 3T3-L1 cells. Additionally, W. cibaria-biotransformed whey also decreased the mRNA and protein expressions of lipoprotein lipase and adipocyte fatty acid-binding protein, which are regulated by PPARγ. Moreover, W. cibaria-biotransformed whey inhibited the expression of adipokines, resistin, and leptin. Collectively, these results suggest that whey biotransformed by W. cibaria has the potential to exert anti-adipogenic effects by inhibiting intracellular signaling events of adipogenic-related transcription factors and target genes.

Anti-Obesity Effect of Kimchi with Starter Cultures in 3T3-L1 Cells.

Lactic acid bacteria (LAB) isolated from kimchi have various functions, including antioxidant, anti-inflammation, and anti-obesity activities, and are therefore widely used in the food, pharmaceutical, and medical fields. To date, the health functionalities of LAB have been widely reported; however, those of kimchi fermented with LAB as a starter have rarely been reported. Therefore, research on the selection of LAB with anti-obesity activity and the health functionality of kimchi fermented with LAB is needed. In the present study, LAB with anti-obesity activity were initially selected by measuring the Oil-Red O intensity. Among the four LAB strains, anti-obesity activity was confirmed by measuring cell viability, lipid levels, and lipid accumulation. Then, starter kimchi (SK) was prepared by inoculating selected LABs, and its pH, total acidity, and salinity were compared with those of naturally fermented kimchi (NK). Lastly, anti-obesity activity was also investigated in 3T3-L1 cells. Selected LAB showed no cytotoxicity up to 107 CFU/ml, with Lactobacillus brevis JC7 and Leuconostoc mesenteroides KCKM0828 having higher inhibitory effects on TG, TC content and lipid accumulation. Most SKs showed fermentation properties similar to those of the NK. SKs showed no cytotoxicity at concentrations of up to 1,000 µg/ml. SKs showed strong inhibitory effects on TG content, lipid accumulation, and obesity-related gene and protein expressions. Taken together, the utilization of LAB as a starter could improve the health benefits of kimchi.

In vitro anti-inflammatory and antibiofilm activities of bacterial lysates from lactobacilli against oral pathogenic bacteria.

Postbiotics are functional biological compounds, such as bacterial lysates (BLs) released from probiotic bacteria. Although postbiotics exert various bioactivities, the anti-inflammatory and antibiofilm activities of BLs against oral pathogenic bacteria have not been investigated. In the present study, pretreatment with BLs extracted from Lactobacillus plantarum and L. rhamnosus GG suppressed the mRNA and protein expression levels of inflammatory mediators induced by the lipopolysaccharide (LPS) of Porphyromonas gingivalis in RAW 264.7 cells. Both BLs attenuated P. gingivalis LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs) and activation of nuclear factor-κB (NF-κB), suggesting that BLs inhibit periodontal inflammatory responses by regulating the MAPK and NF-κB signaling pathways. Moreover, both BLs interfered with biofilm formation by Streptococcus mutans; however, they did not eradicate the established S. mutans biofilm. Furthermore, both BLs downregulated gtfB, gtfC, and gtfD responsible for biofilm formation by S. mutans, suggesting that BLs reduce the synthesis of extracellular polysaccharide and thereby reduce S. mutans biofilm. Taken together, these results suggest that BLs of L. plantarum and L. rhamnosus GG can attenuate periodontal inflammation and dental caries and thus contribute to the improvement of oral health.

Skimmed milk fermented by lactic acid bacteria inhibits adipogenesis in 3T3-L1 pre-adipocytes by downregulating PPARγ via TNF-α induction in vitro.

The murine 3T3-L1 pre-adipocyte cell line is widely used as an in vitro model for adipogenesis because of its similarities to primary fat cells. The aim of this study was to investigate the intracellular mechanisms by which skimmed milk fermented by two lactic acid bacteria (LAB), Enterococcus faecalis and Lactobacillus plantarum, inhibited the differentiation of 3T3-L1 pre-adipocytes. Skimmed milk fermented by both LAB, but not non-fermented skimmed milk, significantly reduced the accumulation of lipid droplets and cellular triglycerides in a concentration-dependent manner. The mRNA and protein levels of peroxisome proliferator-activated receptor γ (PPARγ) were markedly inhibited in the presence of skimmed milk fermented by both LAB. Furthermore, the skimmed milk fermented by both LAB decreased the mRNA and protein expressions of PPARγ-targeting genes, lipoprotein lipase and adipocyte fatty acid-binding protein. Under the same circumstances, resistin mRNA expression was downregulated, but not leptin mRNA expression. In contrast, skimmed milk fermented by both LAB significantly upregulated tumor necrosis factor-α (TNF-α). These results suggest that LAB-fermented skimmed milk inhibits adipogenesis by inhibiting a master transcription factor PPARγ via the upregulation of the proinflammatory cytokine TNF-α in 3T3-L1 cells.

Bioconversion Products of Whey by Lactic Acid Bacteria Exert Anti-Adipogenic Effect.

Microbial bioconversion using lactic acid bacteria (LAB) provides several human health benefits. Although whey and whey-derived bioactive compounds can contribute to an improvement in human health, the potential anti-obesity effect of whey bioconversion by LAB has not been well studied. This study aimed to investigate whether bioconversion of whey by Pediococcus pentosaceus KI31 and Lactobacillus sakei KI36 (KI31-W and KI36-W, respectively) inhibits 3T3-L1 preadipocyte differentiation. Both KI31-W and KI36-W reduced intracellular lipid accumulation significantly, without decreasing 3T3-L1 preadipocyte proliferation. In addition, obesity-related transcription factor (peroxisome proliferator-activated receptor γ) and genes (adipocyte fatty acid-binding protein and lipoprotein lipase) were down-regulated significantly in 3T3-L1 cells in the presence of KI31-W and KI36-W. Collectively, these results suggest that bioconversion of whey by LAB exhibits anti-adipogenic activity and may be applied as a therapeutic agent for obesity.