Bao Le

Efficacy of Lactobacillus plantarum in prevention of inflammatory bowel disease

Graphical abstract

Soyasaponin Ag inhibits α‑MSH‑induced melanogenesis in B16F10 melanoma cells via the downregulation of TRP‑2

Saponins, which are glycosylated, represent a diverse group of biologically functional products in plants. In the present study, we investigated the effects of soyasaponin Ag, a secondary metabolite extracted from soybean, on α-melanocyte-stimulating hormone (α-MSH)-induced melanin synthesis in B16F10 mouse melanoma cells and the underlying molecular mechanisms. To elucidate the mechanisms through which soyasaponin Ag inhibits melanin synthesis, we performed cellular tyrosinase activity assays and analyzed the expression of the melanogenesis-related genes, tyrosinase, tyrosinase-related protein (TRP)-1 and TRP-2. We demonstrated that soyasaponin Ag inhibited α-MSH-induced melanin synthesis in melanoma cells. Of note, soyasaponin Ag had no inhibitory effect on intracellular tyrosinase activity. However, soyasaponin Ag inhibited TRP-2 expression in a dose-dependent manner. Therefore, the depigmenting effect of soyasaponin Ag may be due to the inhibition of tyrosinase expression or the enhancement of tyrosinase degradation. Moreover, soyasaponin Ag did not exert any toxic on B16F10 mouse melanoma cells, suggesting that soyasaponin is a safe component for use in skin care cosmetic formulations that are used for skin whitening.

Anti-inflammatory effects of soyasapogenol I-αa via downregulation of the MAPK signaling pathway in LPS-induced RAW 264.7 macrophages

The crude extract of soyasaponins was reported to possess anti-inflammatory activity. We determined the new purity group I saponin, I-αa and I-γa that was isolated from wild soybean (Glycine soja) in terms of its efficacy in protecting RAW 264.7 macrophages from lipopolysaccharide (LPS)-stimuli. Cells were treated with soyasaponin I-αa/I-γa (30-300 μΜ) and LPS (0.1 μg/mL) for 24 h. Soyasaponin I-αa inhibited nitric oxide (NO) production at 100 μg/mL, while soyasaponin I-γa demonstrated this effect at a higher concentration (200 μg/mL). The expression levels of iNOS and COX-2 enzymes were downregulated by both soyasaponins. Soyasaponin I-αa exerted its effect via the TNF-α and IL-1β cytokines. However, soyasaponin I-γa only inhibited the expression of TNF-α. The inflammatory effect of group I soyasaponin was mainly mediated via the phosphorylation of the p38 and JNK proteins. Collectively, these results suggested the potential anti-inflammatory effects of soyasaponins.

Reconstructing the Phylogeny of Capsosiphon fulvescens (Ulotrichales, Chlorophyta) from Korea Based on rbcL and 18S rDNA Sequences

Capsosiphon fulvescens is a filamentous green algae in the class Ulvophyceae. It has been consumed as food with unique flavor and soft texture to treat stomach disorders and hangovers, and its economic value justifies studying its nutritional and potential therapeutic effects. In contrast to these applications, only a few taxonomic studies have been conducted on C. fulvescens. In particular, classification and phylogenetic relationships of the C. fulvescens below the order level are controversial. To determine its phylogenetic position in the class, we used rbcL and 18S rDNA sequences as molecular markers to construct phylogenetic trees. The amplified rbcL and 18S rDNA sequences from 4 C. fulvescens isolates (Jindo, Jangheung, Wando, and Koheung, Korea) were used for phylogenetic analysis by employing three different phylogenetic methods: neighbor joining (NJ), maximum parsimony (MP), and maximum likelihood (ML). The rbcL phylogenetic tree showed that all taxa in the order Ulvales were clustered as a monophyletic group and resolved the phylogenetic position of C. fulvescens in the order Ulotrichales. The significance of our study is that the 18S rDNA phylogenetic tree shows the detailed taxonomic position of C. fulvescens. In our result, C. fulvescens is inferred as a member of Ulotrichaceae, along with Urospora and Acrosiphonia.

Cissus quadrangularis extract (CQR-300) inhibits lipid accumulation by downregulating adipogenesis and lipogenesis in 3T3-L1 cells

Highlights • CQR-300 inhibited lipid accumulation in 3T3-L1 adipocytes.• CQR-300 inhibited the differentiation of adipocytes by regulating adipogenesis.• CQR-300 reduced fatty acids and triglyceride accumulation via downregulating lipogenesis.

Identification of a Novel Potential Probiotic Lactobacillus plantarum FB003 Isolated from Salted-Fermented Shrimp and its Effect on Cholesterol Absorption by Regulation of NPC1L1 and PPARα

Cholesterol-lowering activity is an important health benefit of lactic acid bacteria (LAB). This study aimed to screen LAB strains with cholesterol-lowering activities from salted fermented shrimp and evaluate probiotic characteristics and cholesterol-lowering potentials of these LAB isolates. Among 191 lactic acid strains isolated from traditional salted-fermented shrimp food, FB003 isolate showed the highest cholesterol-lowering activity and investigated as probiotics with cholesterol-lowering ability. Biochemical analysis and 16S rRNA sequencing revealed that this LAB isolate was Lactobacillus plantarum FB003. To screen probiotic trait, L. plantarum FB003 was found to be susceptible to six antibiotics tested and broad-spectrum antimicrobial activity. It also produced various enzymes such as galactosidase, glucosidase, and mannosidase. In addition, this strain showed autoaggregation, and coaggregation capacity for various pathogens. Moreover, it could adhere to Caco-2 cells and be exerted lowering cholesterol effects in Caco-2 cells via an upregulation of PPARα to inhibit NPC1L1 mRNA expression. Strain L. plantarum FB003 might be effective as a candidate probiotic with high cholesterol-lowering activity. The results of the present study suggest that L. plantarum FB003 have an impact on preventing high cholesterol level and may be used as starter culture for shrimp fermentation.

Probiotic potential of novel Lactobacillus strains isolated from salted-fermented shrimp as antagonists for Vibrio parahaemolyticus

Lactobacillus strains have been considered good candidates as biological control agents for prevention or treatment of plant and animal infections. One L. plantarum strain FB003 and three strains (FB011, FB081, and FB110) which closed to L. sakei were isolated from fermented and salted shrimp and their abilities in inhibiting growth of Vibrio parahaemolyticus were characterized. These strains were selected as potential probiotics based on their oro-gastro-intestinal resistance, gut colonization, adhesion to Caco-2 cells, antimicrobial activities, antibiotic resistance, and safety aspects. Results of this study revealed that these isolates possessed high aggregation activities against pathogens in host intestines. Strain FB011 strain showed higher coaggregation and immunomodulatory activity in the gastro-intestinal tract than L. plantarum. These difference effects of Lactobacillus strains provide valuable information about using them to prevent Vibrio infections in the aquaculture industry.

Streptomyces sp. strain SK68, isolated from peanut rhizosphere, promotes growth and alleviates salt stress in tomato (Solanum lycopersicum cv. Micro-Tom)

A novel actinobacterium, strain SK68, was isolated from the rhizosphere of peanut plant and its salinity stress alleviation ability was studied using tomato (Solanum lycopersicum cv. Micro-Tom) plants. Based on 16S rDNA based phylogenetic analysis, strain SK68 has been identified as a Streptomyces sp. Strain SK68 had branched substrate mycelium bearing smooth surfaced spores and the spore colour is brownish grey on ISP4 medium. It exhibited enzyme activities such as xylanase, cellulase, amylase, and pectinase and degraded hypoxanthine, casein, and L-tyrosine. The strain SK68 differed in its banding pattern in BOX-PCR and RAPD fingerprinting compared to the closely matching type strains Streptomyces erythrochromogenes NBRC 3304T (AB184746), S. flavotricini NBRC 12770T (AB184132), S. racemochromogenes NBRC 12906T (AB184235), and S. polychromogenes NBRC 13072T (NR041109). Strain SK68 was evaluated for its salinity stress-alleviating activity in tomato plants with 180 mmol/L NaCl under gnotobiotic condition. A significant increase in plant biomass was observed in strain SK68-inoculated tomato plants under salt stress compared to control and salt-stressed non-inoculated plants.

Characterization of a chitinase from Salinivibrio sp. BAO-1801 as an antifungal activity and a biocatalyst for producing chitobiose

Salinivibrio genus is commonly found in salted seafood products. In this study, chitinase produced by Salinivibrio sp. BAO‐1801 isolated from salted fermented shrimp was purified and subsequently characterized. The molecular weight of BAO‐1801 chitinase was approximately 94.2 kDa by SDS–PAGE analysis. It was classified as a chitinase C based on homology analysis of its N‐terminal amino acid residues. This strain BAO‐1801 chitinase was then used for synthesis of (GlcNAc)2. Degradation of colloidal chitin and N‐acetyl chitooligosaccharides by BAO‐1801 chitinase was then analyzed and (GlcNAc)2 was identified as the main product by thin layer chromatography and high‐performance liquid chromatography. Effects of temperature and pH on activity and stability of BAO‐1801 chitinase were also investigated. Furthermore, this enzyme inhibited fungal growth in a dose‐dependent manner. Taken together, these results suggest that this Salinivibrio or its chitinase can be used for the enzymatic degradation of chitin to produce chitobiose in industrial process.