OBJECTIVES: To explore the mechanism of Lacticaseibacillus paracasei E6 for improving vinorelbine-induced immunosuppression in zebrafish. METHODS: The intestinal colonization of L. paracasei E6 labeled by fluorescein isothiocyanate (FITC) in zebrafish was observed under fluorescence microscope. In a zebrafish model of vinorelbine-induced immunosuppression, the immunomodulatory activity of L. paracasei E6 was assessed by analyzing macrophage and neutrophil counts in the caudal hematopoietic tissue (CHT), the number of T-lymphocyte, and the expressions of interleukin-12 (IL-12) and interferon-γ (IFN-γ). The contents of short-chain fatty acids (SCFAs) in L. paracasei E6 fermentation supernatant and the metabolites of L. paracasei E6 in zebrafish were detected by LC-MS/MS-based targeted metabolomics. The immunomodulatory effects of the SCFAs including sodium acetate, sodium propionate and sodium butyrate were evaluated in the zebrafish model of immunosuppression. RESULTS: After inoculation, green fluorescence of FITC-labeled L. paracasei E6 was clearly observed in the intestinal ball, midgut and posterior gut regions of zebrafish. In the immunocompromised zebrafish model, L. paracasei E6 significantly alleviated the reduction of macrophage and neutrophil counts in the CHT, increased the fluorescence intensity of T-lymphocytes, and promoted the expressions of IL-12 and IFN-γ. Compared with MRS medium, L. paracasei E6 fermentation supernatant showed significantly higher levels of acetic acid, propionic acid and butyric acid, which were also detected in immunocompromised zebrafish following treatment with L. paracasei E6. Treatment of the zebrafish model with sodium acetate and sodium propionate significantly increased macrophage and neutrophil counts in the CHT and effectively inhibited vinorelbine-induced reduction of thymus T cells. CONCLUSIONS L. paracasei E6 can improve vinorelbine-induced immunosuppression in zebrafish through its SCFA metabolites acetic acid and propionic acid.
Animals ; Zebrafish/immunology* ; Acetic Acid/metabolism* ; Propionates/metabolism* ; Fatty Acids, Volatile/metabolism*

To explore the mechanism by which vinegar-processed Euphorbiae Pekinensis Radix regulates gut microbiota and reduces intestinal toxicity, this study aimed to identify key microbial communities related to vinegar-induced detoxification and verify their functions. Using a derivatization method, the study measured the content of short-chain fatty acids(SCFAs) in feces before and after vinegar-processing of Euphorbiae Pekinensis Radix. Combined with the results of previous gut microbiota sequencing, correlation analysis was used to identify key microbial communities related to SCFAs content. Through single-bacterium transplantation experiments, the role of key microbial communities in regulating SCFAs metabolism and alleviating the intestinal toxicity of Euphorbiae Pekinensis Radix was clarified. Fecal extracts were then added to a co-culture system of Caco-2 and RAW264.7 cells, and toxicity differences were evaluated using intestinal tight junction proteins and inflammatory factors as indicators. Additionally, the application of a SCFAs receptor blocker helped confirm the role of SCFAs in reducing intestinal toxicity during vinegar-processing of Euphorbiae Pekinensis Radix. The results of this study indicated that vinegar-processing of Euphorbiae Pekinensis Radix improved the decline in SCFAs content caused by the raw material. Correlation analysis revealed that Bifidobacterium was positively correlated with the levels of acetic acid, propionic acid, isobutyric acid, n-butyric acid, isovaleric acid, and n-valeric acid. RESULTS:: from single-bacterium transplantation experiments demonstrated that Bifidobacterium could mitigate the reduction in SCFAs content induced by raw Euphorbiae Pekinensis Radix, enhance the expression of tight junction proteins, and reduce intestinal inflammation. Similarly, cell experiment results confirmed that fecal extracts from Bifidobacterium-transplanted mice alleviated inflammation and increased the expression of tight junction proteins in intestinal epithelial cells. The use of the free fatty acid receptor-2 inhibitor GLPG0974 verified that this improvement effect was related to the SCFAs pathway. This study demonstrates that Bifidobacterium is the key microbial community responsible for reducing intestinal toxicity in vinegar-processed Euphorbiae Pekinensis Radix. Vinegar-processing increases the abundance of Bifidobacterium, elevates the intestinal SCFAs content, inhibits intestinal inflammation, and enhances the expression of tight junction proteins, thereby improving the intestinal toxicity of Euphorbiae Pekinensis Radix.
Animals ; Mice ; Humans ; Acetic Acid/chemistry* ; Gastrointestinal Microbiome/drug effects* ; Fatty Acids, Volatile/metabolism* ; Bifidobacterium/genetics* ; Caco-2 Cells ; Intestines/microbiology* ; Drugs, Chinese Herbal/chemistry* ; Euphorbia/toxicity* ; RAW 264.7 Cells ; Male ; Feces/chemistry* ; Intestinal Mucosa/drug effects*

Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.
Acetic Acid ; Biofuels ; Biomass ; Culture Media ; Fatty Acids ; Hydrolysis ; Industrial Microbiology ; Lignin ; chemistry ; Linoleic Acid ; Lipids ; biosynthesis ; Oleic Acid ; Rhodotorula ; metabolism

OBJECTIVETo investigate the therapeutic mechanism of Weiweifang (WWF, a Chinese herbal preparation) on gastric ulcer in rats viewing from metabonomics.

METHODSWistar rats were made to gastric model by acetic acid cauterization and randomized into the model group, the spontaneously healing group and the three WWF treatment groups, and a group of normal rats was set for control. Metabolic spectra of gastric mucosa extraction of rats were acquired with gas chromatography-mass spectrometry (GC-MS) technique. After being pre-processing, data were subjected to partial least squares discriminant analysis (PLS-DA) to discover the biomarkers in rats of the normal group and the model group. The therapeutic effect of WWF on experimental gastric ulcer was assessed by principal component analyses (PCA), and its action of mechanism was explained viewing from the changes of biomarkers.

RESULTSSpectra of biomarkers, including organic acids, fatty acids, amino acids, etc. in model rats were statistically different to those in normal rats, which demonstrated that the energy and substance metabolisms were disordered in rats with gastric ulcer. WWF could cure gastric ulcer effectively by way of regulating the metabolism of gastric mucosa.

CONCLUSIONThe therapeutic mechanism of WWF on experimental gastric ulcer in rats is revealed integrally by metabonomics in this study, displaying prominently the characteristics of Chinese medicine multiple targets comprehensive therapy.

Acetic Acid ; Amino Acids ; metabolism ; Animals ; Drugs, Chinese Herbal ; therapeutic use ; Fatty Acids ; metabolism ; Gas Chromatography-Mass Spectrometry ; Gastric Mucosa ; metabolism ; Male ; Metabolomics ; methods ; Phytotherapy ; Rats ; Rats, Wistar ; Stomach Ulcer ; chemically induced ; drug therapy ; metabolism

Spinal gabapentin has been known to show the antinociceptive effect. Although several assumptions have been suggested, mechanisms of action of gabapentin have not been clearly established. The present study was undertaken to examine the action mechanisms of gabapentin at the spinal level. Male SD rats were prepared for intrathecal catheterization. The effect of gabapentin was assessed in the formalin test. After pretreatment with many classes of drugs, changes of effect of gabapentin were examined. General behaviors were also observed. Intrathecal gabapentin produced a suppression of the phase 2 flinching, but not phase 1 in the formalin test. The antinociceptive action of intrathecal gabapentin was reversed by intrathecal NMDA, AMPA, D-serine, CGS 15943, atropine, and naloxone. No antagonism was seen following administration of bicuculline, saclofen, prazosin, yohimbine, mecamylamine, L-leucine, dihydroergocristine, or thapsigargin. Taken together, intrathecal gabapentin attenuated only the facilitated state. At the spinal level, NMDA receptor, AMPA receptor, nonstrychnine site of NMDA receptor, adenosine receptor, muscarinic receptor, and opioid receptor may be involved in the antinociception of gabapentin, but GABA receptor, L-amino acid transporter, adrenergic receptor, nicotinic receptor, serotonin receptor, or calcium may not be involved.
Acetic Acids/administration & dosage ; Acetic Acids/metabolism ; Acetic Acids/pharmacology* ; Adrenergic Antagonists/metabolism ; Adrenergic alpha-Antagonists/metabolism ; Analgesics/administration & dosage ; Analgesics/metabolism ; Analgesics/pharmacology* ; Animals ; Atropine/metabolism ; Dihydroergocristine/metabolism ; Enzyme Inhibitors/metabolism ; Excitatory Amino Acid Agonists/metabolism ; GABA Antagonists/metabolism ; Injections, Spinal ; Leucine/metabolism ; Male ; Mecamylamine/metabolism ; Muscarinic Antagonists/metabolism ; N-Methylaspartate/metabolism ; Naloxone/metabolism ; Narcotic Antagonists/metabolism ; Nicotinic Antagonists/metabolism ; Pain Measurement ; Quinazolines/metabolism ; Rats ; Rats, Sprague-Dawley ; Serine/metabolism ; Spinal Cord/drug effects* ; Thapsigargin/metabolism ; Triazoles/metabolism ; alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid/metabolism