Structural Characterization and Antidepressant-like Effects of Polygonum sibiricum Polysaccharides on Regulating Microglial Polarization in Chronic Unpredictable Mild Stress-Induced Zebrafish.

Polysaccharides are one of the main active ingredients of Polygonum sibiricum (PS), which is a food and medicine homolog used throughout Chinese history. The antidepressant-like effects of PSP and its underlying mechanisms remain elusive, especially the regulation of microglial polarization. The current study determined the chemical composition and structural characteristics of PSP. Then, the chronic unpredictable mild stress (CUMS) procedure was carried out on the zebrafish for 5 weeks, and PSP was immersed for 9 days (1 h/d). The body weight of zebrafish was monitored, and behavioral tests, including the novel tank test and light and dark tank test, were performed to evaluate the antidepressant-like effects of PSP. Then, the function of the hypothalamic-pituitary-interrenal (HPI) axis, the levels of peripheral inflammation, neuronal and blood-brain barrier damage in the mesencephalon and telencephalon, and the mRNA expression of M1/M2 phenotype genes in the brain were examined. PSP samples had the typical structural characteristics of polysaccharides, consisting of glucose, mannose, and galactose, with an average Mw of 20.48 kDa, which presented porous and agglomerated morphologies. Compared with untreated zebrafish, the depression-like behaviors of CUMS-induced zebrafish were significantly attenuated. PSP significantly decreased the levels of cortisol and pro-inflammatory cytokines and increased the levels of the anti-inflammatory cytokines in the body of CUMS-induced depressive zebrafish. Furthermore, PSP remarkably reversed the neuronal and blood-brain barrier damage in the mesencephalon and telencephalon and the mRNA expression of M1/M2 phenotype genes in the brain. These findings indicated that the antidepressant-like effects of PSP were related to altering the HPI axis hyperactivation, suppressing peripheral inflammation, inhibiting neuroinflammation induced by microglia hyperactivation, and modulating microglial M1/M2 polarization. The current study provides the foundations for future examinations of PSP in the functional foods of emotional regulation.

Effects of semidry milling on the properties of highland barley flour and the quality of highland barley bread.

BACKGROUND: This study aimed to investigate the effects of semidry milling on the quality attributes of highland barley flour and highland barley bread. Highland barley flours were prepared by dry (DBF), semidry (SBF), and wet (WBF) milling methods. The properties of different highland barley flours were analyzed, and highland barley breads made from different highland barley flours were evaluated. RESULTS: The results showed that WBF had the lowest damaged starch content (15.2 g kg-1 ), and the contents of damaged starch in SBF-35 and SBF-40 (43.5 g kg-1 and 24.1 g kg-1 respectively) were lower than that of DBF (87.6 g kg-1 ). And SBF-35 and SBF-40 with large particles exhibited low hydration performance. In addition, SBF-35 and SBF-40 had higher pasting viscosity, pasting temperature, ΔH, and relative crystallinity, consequently resulting in better gel properties than other highland barley flours. These properties could help SBF-35 and SBF-40 develop high-quality bread with large specific volume and superior crumb structure and texture that is similar to the bread with WBF. CONCLUSION: Overall, semidry milling not only could improve the characteristics of HBF, but also avoid high starch damage by dry milling and water wasting by wet milling. What is more, highland barley breads with SBF-35 and SBF-40 had preferable appearance and crumb texture. Therefore, semidry milling could be regarded as a feasible way to produce highland barley flour. © 2023 Society of Chemical Industry.

Gut microbial fermentation promotes the intestinal anti-inflammatory activity of Chinese yam polysaccharides.

Plant polysaccharides possess many health-promoting properties, which are closely related to the digestion, absorption and utilization of polysaccharides in the host. The characteristic changes in Chinese yam polysaccharide (CYP) during simulated gastrointestinal digestion and faecal fermentation, as well as the intestinal anti-inflammatory effects of CYP and fermented CYP, were studied. The molecular weight of CYP remained unchanged during gastrointestinal digestion. After 24 h of faecal fermentation, free glucose and mannose released from CYP were utilized by gut microbiota, and the production of short-chain fatty acids increased. Simultaneously, CYP improved the growth of Bifidobacterium and Megasphaera. Compared with CYP, faecal fermented CYP exhibited greater suppression of anti-inflammatory mediators and increased intestinal tight junction expression in LPS-stimulated coculture Caco-2/Raw264.7 cells. The obtained results reveal that the role of CYP in promoting gut health is closely related to the interactions between CYP and gut microbes, and CYP has potential as an anti-inflammatory adjuvant in enteritis therapy.

Analysis of the noncoding RNA regulatory networks of H37Rv- and H37Rv△1759c-infected macrophages.

Noncoding RNAs regulate the process of Mycobacterium tuberculosis (M. tb) infecting the host, but there is no simultaneous transcriptional information of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) and the global regulatory networks of non-coding RNA. Rv1759c, a virulence factor, is a member of protein family containing the proline-glutamic acid (PE) in M. tb, which can increase M. tb survival. To reveal the noncoding RNA regulatory networks and the effect of Rv1759c on non-coding RNA expression during M. tb infection, we collected samples of H37Rv- and H37Rv△1759c-infected macrophages and explored the full transcriptome expression profile. We found 356 mRNAs, 433 lncRNAs, 168 circRNAs, and 12 miRNAs differentially expressed during H37Rv infection, 356 mRNAs, 433 lncRNAs, 168 circRNAs, and 12 miRNAs differentially expressed during H37Rv△1759c infection. We constructed lncRNA/circRNA-miRNA-mRNA regulatory networks during H37Rv and H37Rv△1759c infection. We demonstrated the role of one of the hubs of the networks, hsa-miR-181b-3p, for H37Rv survival in macrophages. We discovered that the expression changes of 68 mRNAs, 92 lncRNAs, 26 circRNAs, and 3 miRNAs were only related to the deletion of Rv1759c by comparing the transcription profiles of H37Rv and H37Rv△1759c. Here, our study comprehensively characterizes the transcriptional profiles in THP1-derived-macrophages infected with H37Rv and H37Rv△1759c, which provides support and new directions for in-depth exploration of noncoding RNA and PE/PPE family functions during the infection process.

Longan pulp polysaccharides regulate gut microbiota and metabolites to protect intestinal epithelial barrier.

Longan pulp polysaccharide is a bioactive component with prebiotic activity and intestinal barrier protection. This study aimed to evaluate the influence of digestion and fermentation on the bioavailability and intestinal barrier protection of polysaccharide LPIIa from longan pulp. The molecular weight of LPIIa didn't change significantly after gastrointestinal digestion in vitro. After fecal fermentation, 56.02% of LPIIa was consumed by gut microbiota. The short-chain fatty acid level in LPIIa group was 51.63% higher than that in blank group. LPIIa intake also increased short-chain fatty acid production and G-protein-coupled receptor 41 expression in the colon of mice. Moreover, LPIIa improved the relative richness of Lactobacillus, Pediococcus, and Bifidobacterium in colon content. Compared to LPIIa, fecal fermented LPIIa better protected intestinal epithelial barrier by increasing Zonula occludens-1 expression. These results provided an important basis for the design of functional food based on longan polysaccharides to prevent intestinal barrier damage related diseases.

Repurposing an Antioxidant to Kill Mycobacterium tuberculosis by Targeting the 50S Subunit of the Ribosome.

Tuberculosis and drug-resistant TB remain serious threats to global public health. It is urgent to develop novel anti-TB drugs in order to control it. In addition to redesigning and developing new anti-TB drugs, drug repurposing is also an innovative way to develop antibacterial drugs. Based on this method, we discovered SKQ-1 in the FDA-approved drug library and evaluated its anti-TB activity. In vitro, we demonstrated that SKQ-1 engaged in bactericidal activity against drug-sensitive and -resistant Mtb and confirmed the synergistic effects of SKQ1 with RIF and INH. Moreover, SKQ-1 showed a significant Mtb-killing effect in macrophages. In vivo, both the SKQ-1 treatment alone and the treatment in combination with RIF were able to significantly reduce the bacterial load and improve the survival rate of G. mellonella infected with Mtb. We performed whole-genome sequencing on screened SKQ-1-resistant strains and found that the SNP sites were concentrated in the 50S ribosomal subunit of Mtb. Furthermore, we proved that SKQ-1 can inhibit protein translation. In summary, from the perspective of drug repurposing, we discovered and determined the anti-tuberculosis effect of SKQ-1, revealed its synergistic effects with RIF and INH, and demonstrated its mechanism of action through targeting ribosomes and disrupting protein synthesis, thus making it a potential treatment option for DR-TB.

Effects of egg powder on the structure of highland barley dough and the quality of highland barley bread.

The influences of egg white (EW), egg yolk (EY) and whole egg (WE) on the structure of highland barley dough and the quality of highland barley bread were explored. The results showed that egg powder reduced G' and G" of highland barley dough, which led to the softer texture of dough and endowed bread with a larger specific volume. EW increased the percentage of ß-sheet of highland barley dough, EY and WE promoted the transformation from random coil to ß-sheet and α-helix. Meanwhile, more disulfide bonds were formed from free sulfhydryl groups in the doughs with EY and WE. These properties of highland barley dough could help highland barley bread develop a preferable appearance and textural feature. It is worth noting that highland barley bread containing EY has more flavorful substances and a better crumb structure, which were similar to that of whole wheat bread. The highland barley bread with EY received a high score according to the sensory evaluation in consumer acceptance.

Structural elucidation, anti-inflammatory activity and intestinal barrier protection of longan pulp polysaccharide LPIIa.

In this study, LPIIa, a purified polysaccharide from longan pulp, was isolated. Its anti-inflammatory activity and intestinal barrier protection were investigated with LPS-treated co-culture model of Caco-2 cells and RAW 264.7 macrophages. The average molecular weight LPIIa was 159.3 kDa. Its detailed structure was shown below. The backbone of LPIIa was composed of (1→3,4)-linked-α-Rhap, (1→4)-linked-ß-Galp, (1→6)-linked-ß-Galp, and (1→3,6)-linked-ß-Galp, with branches at the O-4 of Rha and O-3 of Gal, consisting of side chains of α-Araf, ß-Galp, and α-Glcp. In LPS-induced RAW 264.7 macrophages, LPIIa suppressed the production of inflammatory mediators, including TNF-α, IL-6, NO, and PGE2, and inhibited iNOS and COX-2 gene expression. In addition, LPIIa attenuated intestinal tight-junctional channel protein Claudin-2 expression and increased tight-junctional barrier protein ZO-1 expression in Caco-2 cells. Knowing the structural features and activities of longan polysaccharide gives insights into longan polysaccharide application as an anti-inflammatory agent or adjuvant in curing the intestinal inflammation.

In vitro digestion and human gut microbiota fermentation of longan pulp polysaccharides as affected by Lactobacillus fermentum fermentation.

This study investigated the effect of Lactobacillus fermentum fermentation treatment on the gastrointestinal digestion and fermentation in vitro of polysaccharides from longan pulp. Polysaccharide isolated from unfermented and fermented longan pulp named LP and LP-F, respectively. The molecular weight of LP-F declined from 109.62 ± 10.66 kDa to 51.46 ± 6.26 kDa while that of LP declined from 221.63 ± 2.41 kDa to 69.68 ± 2.36 kDa with gastrointestinal digestion. At same time, the reducing sugars content of LP and LP-F were both increased significantly. In addition, after 48 h gut microbiota fermentation, there were more total short chain fatty acids and acetic acid, as well as more Enterococcus, Bifidobacterium, and Clostridium in LP-F fermentation culture than those in LP fermentation culture. Moreover, LP-F fermentation culture showed lower pH value and less residual carbohydrate percentage than that of LP. These results indicated that LP-F is easier than LP to be fermented by human gut microbiota.

Rice Bran Phenolic Extract Protects against Alcoholic Liver Injury in Mice by Alleviating Intestinal Microbiota Dysbiosis, Barrier Dysfunction, and Liver Inflammation Mediated by the Endotoxin-TLR4-NF-κB Pathway.

Alcoholic liver injury, known as the most general result of chronic alcohol intake, is induced by inflammatory responses, which is activated by intestine-derived endotoxins formed from intestinal dysbiosis. The hepatoprotective activity of rice bran phenolic extract (RBPE) on ethanol-fed mice was investigated for the first time in this study, and the underlying mechanism was explored from gut microbiota, barrier function, and hepatic inflammation. Mice were fed an alcohol-containing liquid diet alone or in mixture with RBPE for 8 weeks. RBPE treatment mitigated ethanol-induced liver damage, evidenced by the declined lipid profile levels and hepatic function markers. Moreover, ethanol intake induced intestinal microbiota dysbiosis, which was attenuated by RBPE supplementation. RBPE treatment improved the alcohol-induced decrease in the expression of ZO-1, Claudin-1, Claudin-4, and Reg3g, revealing the ameliorative effect of RBPE on intestinal barrier dysfunction. Furthermore, RBPE treatment repressed the alcohol-induced trigger of the hepatic endotoxin-TLR4-NF-κB pathway, followed by the mitigated liver inflammation. The findings indicate that RBPE supplementation ameliorates intestinal microbiota dysbiosis and barrier dysfunction, inactivates the endotoxin-TLR4-NF-κB pathway, and represses inflammatory responses in liver, and therefore, intake of RBPE or brown rice may be an effective way to mitigate alcoholic liver injury.

Longan pulp polysaccharides relieve intestinal injury in vivo and in vitro by promoting tight junction expression.

The integrity of the intestinal mucosal barrier is important for the health of the host. In this study, longan pulp polysaccharides (LP) prevented the intestinal mucosal injury by increasing the expression of mucin 2, tight junction proteins zonulae occludens-1 (ZO-1), claudin-1, claudin-4, and adherens junction E-cadherin in cyclophosphamide-treated mice. To further identify the principle bioactive component of LP, four acidic polysaccharides (LPIa, LPIIa, LPIIIa, and LPIVa) were purified, and their intestinal protection activity in vitro was compared. LPIa, LPIIa, and LPIIIa displayed an ability to increase mRNA expression of ZO-1, claudin-1, occludin, and E-cadherin in differentiated Caco-2 cells, especially LPIa. LPIa has specific structure characteristics: porous surface structure, a high molecular weight (1.47 × 105 Da), and two specific glycosidic linkages of α-Araf-(1→ and →5)-α-Araf-(1→. These structure characteristics might primarily contribute to greater intestinal barrier protective effect of LPIa.

Longan pulp polysaccharide protects against cyclophosphamide-induced immunosuppression in mice by promoting intestinal secretory IgA synthesis.

This study aimed to explore the effect of longan pulp polysaccharide (LP) on the systemic immunity and intestinal mucosal immunity of immunosuppressive mice. The synthesis process and secretion of intestinal secretory IgA (SIgA) were investigated. Results showed that LP increased the thymus index, spleen index, and serum IgA level in cyclophosphamide (CTX)-treated mice. SIgA secretion in the intestinal lumen was increased by LP as well. The underlying mechanism comes down to the facts as follow: LP increased intestinal cytokines expression and TGFßRII that is associated with pathways of IgA class switch recombination (CSR). By improving protein expression of mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) and integrin α4ß7, LP was beneficial to gut homing of IgA+ plasma cells. LP increased IgA, polymeric immunoglobulin receptor (pIgR), and secretory component (SC) to fortify the SIgA secretion. This study suggested that moderate consumption of LP is helpful for improving systemic immunity and intestinal mucosal immunity via promotion of intestinal SIgA to strengthen the mucosal barrier.

Structural characterization and in vitro gastrointestinal digestion and fermentation of litchi polysaccharide.

This study investigated the structural characteristic and in vitro digestion and fermentation behaviours of polysaccharide from litchi pulp (LPII). The results showed that LPII was 161.24kDa, and consisted of arabinose, galactose, rhamnose and glucose. The glycosidic linkages were identified as α-L-Araf-(1→, →5)-α-Araf-(1→ and →3,6)-ß-D-Galp-(1→. After 4h gastric digestion, the molecular weight (Mw) of LPII was declined and the reducing sugars content (CR) was increased significantly. But, the intestinal digestion had no effect on the structure of LPII. In addition, after 24h gut microbiota fermentation, the neutral sugars content and pH value decreased while total bacteria amount, CR, the production of short-chain fatty acids, acetic acid and n-butyric acid increased. These results showed that LPII could be digested in gastric digestion and fermented in large intestine fermentation broth, but not changed in small intestinal fluid. The digestion and fermentation behaviours of LPII may be related with its structural features.

Dynamic variation in biochemical properties and prebiotic activities of polysaccharides from longan pulp during fermentation process.

Lactic acid bacteria fermentation is an important processing technology for fruits and vegetables. Bioactive compounds such as polysaccharides are altered during the fermentation process. Polysaccharides from longan pulp (LPs) were extracted after different fermentation times and their physicochemical and prebiotic properties were investigated, such as longan polysaccharides named LP-0 and LP-12 means they were extracted from longan pulp fermented for 0 and 12 h, respectively. The yield, contents of neutral sugar and uronic acid, molecular weight (Mw), and monosaccharide composition of LPs were significantly changed with different fermentation times. Specially, the yield and uronic acid content of LPs were first increase and then decline. LP-12 contained the smallest Mw (108.71 ±â€¯5.55 kDa) of the tested LPs (p < 0.05). When compared with unfermented LP-0, the glucose molar percentages of fermented LPs declined, while those of rhamnose and galactose increased, except for LP-6. Fermented LPs also exhibited a stronger stimulatory effect on Lactobacillus strain proliferation, with the proliferative effect of LP-12 being the strongest (p < 0.05). These results suggest that lactic acid bacteria fermentation can change the physicochemical properties and enhance the prebiotic activities of polysaccharides from longan pulp.

Ultrahigh pressure-assisted enzymatic extraction maximizes the yield of longan pulp polysaccharides and their acetylcholinesterase inhibitory activity in vitro.

An extraction method employing ultrahigh pressure-assisted enzymatic treatment was developed and optimized by response surface methodology to increase the yield of longan pulp polysaccharides (LP-UE). A maximum polysaccharides yield of 8.55% was obtained under the optimal conditions of 407MPa ultrahigh pressure maintained for 6min with an enzyme to pretreated material ratio of 1:100, an enzymolysis time of 1.7h and a water to pretreated material ratio of 42ml/g. Subsequently, the physicochemical properties and acetylcholinesterase (AChE) inhibitory activity of LP-UE were compared to those of longan pulp polysaccharides (LP) extracted by hot water (LP-H), ultrahigh pressure (LP-U) or enzymatic treatment (LP-E). Results demonstrated that the extraction yield, hexuronic acid content and AChE inhibitory activity of LP-UE was the highest among the four LP samples. LP-UE was primarily made up of arabinose, glucose, and galactose and was linked mainly by ß-type glycosidic linkage. The FTIR spectrum of LP-UE was very similar to those of LP-H, LP-U, and LP-E. In summary, ultrahigh pressure-assisted enzymatic treatment is a more efficient technique for extracting LP with considerable improvement of both yield and memory enhancement function.