Structural analysis and prebiotic activity of exopolysaccharide produced by probiotic strain Bifidobacterium bifidum EPS DA-LAIM.

Exopolysaccharide (EPS)-producing Bifidobacterium bifidum EPS DA-LAIM was isolated from healthy human feces, the structure of purified EPS from the strain was analyzed, and its prebiotic activity was evaluated. The EPS from B. bifidum EPS DA-LAIM is a glucomannan-type heteropolysaccharide with a molecular weight of 407-1007 kDa, and its structure comprises 2-mannosyl, 6-mannosyl, and 2,6-mannosyl residues. The purified EPS promoted the growth of representative lactic acid bacteria and bifidobacterial strains. Bifidobacterium bifidum EPS DA-LAIM increased nitric oxide production in RAW 264.7 macrophage cells, indicating its immunostimulatory activity. Bifidobacterium bifidum EPS DA-LAIM also exhibited high gastrointestinal tract tolerance, gut adhesion ability, and antioxidant activity. These results suggest that EPS from B. bifidum EPS DA-LAIM is a potentially useful prebiotic material, and B. bifidum EPS DA-LAIM could be applied as a probiotic candidate. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01213-w.

Potential Probiotic Properties of Exopolysaccharide-Producing Lacticaseibacillus paracasei EPS DA-BACS and Prebiotic Activity of Its Exopolysaccharide.

Exopolysaccharide (EPS)-producing Lacticaseibacillus paracasei EPS DA-BACS was isolated from healthy human feces and its probiotic properties, as well as the structure and prebiotic activity of the EPS from this strain were examined. EPS from L. paracasei EPS DA-BACS had a ropy phenotype, which is known to have potential health benefits and is identified as loosely cell-bounded glucomannan-type EPS with a molecular size of 3.7 × 106 Da. EPS promoted the acid tolerance of L. paracasei EPS DA-BACS and provided cells with tolerance to gastrointestinal stress. The purified EPS showed growth inhibitory activity against Clostridium difficile. L. paracasei EPS DA-BACS cells completely inhibited the growth of Bacillus subtilis, Pseudomonas aeruginosa, and Aspergillus brasiliensis, as well as showed high growth inhibitory activity against Staphylococcus aureus and Escherichia coli. Treatment of lipopolysaccharide-stimulated RAW 264.7 cells with heat-killed L. paracasei EPS DA-BACS cells led to a decrease in the production of nitric oxide, indicating the anti-inflammatory activity of L. paracasei EPS DA-BACS. Purified EPS promoted the growth of Lactobacillus gasseri, Bifidobacterium bifidum, B. animalis, and B. faecale which showed high prebiotic activity. L. paracasei EPS DA-BACS harbors no antibiotic resistance genes or virulence factors. Therefore, L. paracasei EPS DA-BACS exhibits anti-inflammatory and antimicrobial activities with high gut adhesion ability and gastrointestinal tolerance and can be used as a potential probiotic.

Facilitated saliva secretion and reduced oral inflammation by a novel artificial saliva system in the treatment of salivary hypofunction.

Saliva substitutes and/or lubricants are commonly employed to lessen dry mouth symptoms by stimulating and/or substituting for the secretion of saliva. In this study, a novel artificial saliva containing inorganic salts, including sodium chloride and potassium chloride, and bactericidal agents, including potassium thiocyanate and lactoperoxidase, was formulated in the form of a solution (DM-sol) or gel (DM-gel). Those in vivo therapeutic efficacies were assessed in terms of saliva secretion and anti-inflammatory activity in rats and mice, respectively. Salivary secretion was promoted by mucosal application of DM-formulations in normal rats. In particular, DM-gel resulted in 2.5- and 1.9-fold greater salivary flow rates compared to normal saline and DM-sol, respectively. In an in vivo efficacy evaluation in diabetic mice with salivary hypofunction, repeated application of DM-formulations alleviated histopathological changes in the buccal mucosa in terms of atrophy and thinning of the epithelium, compared to vehicle, after 4 weeks. Moreover, the DM-sol and DM-gel were comparably effective for relieving periodontal gingivitis, reducing infiltration of inflammatory cells, and normalizing the neutrophil level in the gingival gingiva, after 4 weeks. Therefore, the novel artificial saliva is expected to facilitate salivary secretion and restore physiological conditions in the mouth of patients with salivary hypofunction.

Determination of tiapride in human plasma using hydrophilic interaction liquid chromatography-tandem mass spectrometry.

A rapid, sensitive and selective hydrophilic interaction liquid chromatography-tandem mass spectrometric (HILIC-MS/MS) method for the determination of tiapride in human plasma was developed. Tiapride and internal standard, metoclopramide were extracted from human plasma with dichloromethane at basic pH and analyzed on an Atlantis HILIC silica column with the mobile phase of acetonitrile-ammonium formate (190 mM, pH 3.0) (94:6, v/v). The analytes were detected using an electrospray ionization tandem mass spectrometry in the multiple-reaction-monitoring mode. The standard curve was linear (r=0.999) over the concentration range of 1.00-200 ng/mL. The coefficient of variation and relative error for intra- and interassay at three QC levels were 6.4-8.8% and -2.0-3.6%, respectively. The recoveries of tiapride ranged from 96.3 to 97.4%, with that of metoclopramide (internal standard) being 94.2%. The lower limit of quantification for tiapride was 1.00 ng/mL using 100 microL of plasma sample.

Novel non-vanilloid VR1 antagonist of high analgesic effects and its structural requirement for VR1 antagonistic effects.

A novel non-vanilloid VR1 antagonist consisting of a new vanilloid equivalent exhibits excellent analgesic effects as well as highly potent antagonistic activities in both capsaicin single channel and calcium uptake assays. In addition, the structural requirement for the vanilloid equivalent of the potent VR1 antagonist has also been elucidated.