Tauroursodeoxycholic acid liposome alleviates DSS-induced ulcerative colitis through restoring intestinal barrier and gut microbiota.

Ulcerative colitis (UC) is a chronic and progressive inflammatory disease that damages the colonic mucosa and disrupts the intestinal epithelial barrier. The current clinical treatment for UC is mainly chemotherapy, which has the limited effectiveness and severe side effects. It mainly focuses on the treatment of inflammation while neglecting the repair of the intestinal mucosa and the restoration of the microbiota balance. Here, we aimed to address these challenges by using an amphipathic bile acid -tauroursodeoxycholic acid (TUDCA) to replace cholesterol (CHL) in conventional liposomes. We prepared TUDCA/Emodin liposomes by incorporating the hydrophobic drug emodin. The experimental results indicated that TUDCA/Emodin Lip had uniform particle size distribution, good stability, low cytotoxicity, and exhibited good mucus permeability and anti-inflammatory activity in in vitro experiments, and was able to protect cells from oxidative stress. After oral administration, TUDCA/Emodin Lip significantly alleviated the severity of UC. This was evidenced by increased colon length, decreased inflammation and reduced colonic endoplasmic reticulum stress (ERS). Furthermore, TUDCA/Emodin Lip maintained the normal levels of the tight junction proteins Claudin-1 and ZO-1, thereby restoring the integrity of the intestinal barrier. Importantly, TUDCA/Emodin Lip also promoted the ecological restoration of the gut microbiota, increased overall abundance and diversity. Taken together, TUDCA/Emodin Lip can fundamentally restore intestinal homeostasis, this work provides a new, efficient and easily transformable treatment for UC.

Cyclosporine A-loaded colon-targeted oral nanomicelles self-assembly by galactosylated carboxymethyl chitosan for efficient ulcerative colitis therapy.

An oral galactosylated carboxymethyl chitosan polymeric nanomicelles (Gal-N-CMCS NPs) embedded in chitosan-alginate hydrogel (CA-Gel) was developed to load cyclosporine A (CyA) as therapeutic agents against ulcerative colitis (UC). Galactose modified CMCS with macrophage targeting characteristic and CyA via a simple ultrasonication method to form Gal-N-CMCS/CyA NPs, and mixed CA-Gel to acquire the final formulation (Gal-N-CMCS/CyA Gel). The generated Gal-N-CMCS/CyA NPs displayed a desirable particle size (206.8 nm), negative surface charge (-19.5 mV), and high encapsulating efficiency (89.6 %). The morphology and release profiles were also charactered by transmission electron microscope [1] and dialysis method, respectively. Strikingly, the mucus penetration of Gal-N-CMCS/CyA NPs exceeded 90 % within 90 min. The Gal-N-CMCS NPs internalized by macrophages were 3.3-fold higher than CMCS-N NPs, thereby, enhancing the anti-inflammatory activities of NPs. Meanwhile, these NPs exhibited excellent biocompatibility, reduced the toxic effect of CyA, and targeting ability on inflammatory macrophages both in vitro and in vivo. Most importantly, in vivo studies revealed that CyA NPs could efficiently target the inflamed colon, remarkably alleviate inflammation, repair mucosal and reconstructed colonic epithelial barriers in UC mice induced by dextran sulfate sodium (DSS) via Toll-like receptor 4 -Nuclear factor kappa-B (TLR4-NF-κB) pathway. Our findings suggest that these high-performance and facilely fabricated Gal-N-CMCS/CyA NPs could be developed as a promising drug carrier for oral UC treatment.

Epigallocatechin-3-Gallate Ameliorates Acute Lung Damage by Inhibiting Quorum-Sensing-Related Virulence Factors of Pseudomonas aeruginosa.

The superbug Pseudomonas aeruginosa is among the most formidable antibiotic-resistant pathogens. With declining options for antibiotic-resistant infections, new medicines are of utmost importance to combat with P. aeruginosa. In our previous study, we demonstrated that Epigallocatechin-3-gallate (EGCG) can inhibit the production of quorum sensing (QS)-regulated virulence factors in vitro. Accordingly, the protective effect and molecular mechanisms of EGCG against P. aeruginosa-induced pneumonia were studied in a mouse model. The results indicated that EGCG significantly lessened histopathological changes and increased the survival rates of mice infected with P. aeruginosa. EGCG effectively alleviated lung injury by reducing the expression of virulence factors and bacterial burden. In addition, EGCG downregulated the production of pro-inflammatory cytokines, such as TNF-α, IL-1, IL-6, and IL-17, and increased the expression of anti-inflammatory cytokines IL-4 and IL-10. Thus, the experimental results supported for the first time that EGCG improved lung damage in P. aeruginosa infection by inhibiting the production of QS-related virulence factors in vivo.

Paeonol Attenuates Quorum-Sensing Regulated Virulence and Biofilm Formation in Pseudomonas aeruginosa.

With the prevalence of multidrug-resistant bacteria and clinical -acquired pathogenic infections, the development of quorum-sensing (QS) interfering agents is one of the most potential strategies to combat bacterial infections and antibiotic resistance. Chinese herbal medicines constitute a valuable bank of resources for the identification of QS inhibitors. Accordingly, in this research, some compounds were tested for QS inhibition using indicator strains. Paeonol is a phenolic compound, which can effectively reduce the production of violacein without affecting its growth in Chromobacterium violaceum ATCC 12472, indicating its excellent anti-QS activity. This study assessed the anti-biofilm activity of paeonol against Gram-negative pathogens and investigated the effect of paeonol on QS-regulated virulence factors in Pseudomonas aeruginosa. A Caenorhabditis elegans infection model was used to explore the anti-infection ability of paeonol in vivo. Paeonol exhibited an effective anti-biofilm activity against Gram-negative bacteria. The ability of paeonol to interfere with the AHL-mediated quorum sensing systems of P. aeruginosa was determined, found that it could attenuate biofilm formation, and synthesis of pyocyanin, protease, elastase, motility, and AHL signaling molecule in a concentration- and time-dependent manner. Moreover, paeonol could significantly downregulate the transcription level of the QS-related genes of P. aeruginosa including lasI/R, rhlI/R, pqs/mvfR, as well as mediated its virulence factors, lasA, lasB, rhlA, rhlC, phzA, phzM, phzH, and phzS. In vivo studies revealed that paeonol could reduce the pathogenicity of P. aeruginosa and enhance the survival rate of C. elegans, showing a moderate protective effect on C. elegans. Collectively, these findings suggest that paeonol attenuates bacterial virulence and infection of P. aeruginosa and that further research elucidating the anti-QS mechanism of this compound in vivo is warranted.

EGCG-Mediated Potential Inhibition of Biofilm Development and Quorum Sensing in Pseudomonas aeruginosa.

Pseudomonas aeruginosa (P. aeruginosa), one of the dangerous multidrug resistance pathogens, orchestrates virulence factors production through quorum sensing (QS). Since the exploration of QS inhibitors, targeting virulence to circumvent bacterial pathogenesis without causing significant growth inhibition is a promising approach to treat P. aeruginosa infections. The present study has evaluated the anti-QS and anti-infective activity of epigallocatechin-3-gallate (EGCG), a bioactive ingredient of the traditional green tea, against P. aeruginosa. EGCG showed significant inhibitory effects on the development of biofilm, protease, elastase activity, swimming, and swarming motility, which was positively related to the production of C4-AHL. The expression of QS-related and QS-regulated virulence factors genes was also evaluated. Quantitative PCR analysis showed that EGCG significantly reduced the expression of las, rhl, and PQS genes and was highly correlated with the alterations of C4-AHL production. In-vivo experiments demonstrated that EGCG treatment reduced P. aeruginosa pathogenicity in Caenorhabditis elegans (C. elegans). EGCG increased the survival of C. elegans by 23.25%, 30.04%, and 36.35% in a dose-dependent manner. The findings of this study strongly suggest that EGCG could be a potential candidate for QS inhibition as an anti-virulence compound against bacterial infection.

Autophagy was activated against the damages of placentas caused by nano-copper oral exposure.

Nano-copper (nano-Cu) is widely used in the pharmaceutical field as well as a feed additive for animals owing to its unique physicochemical characteristics and bioactivities. In our previous study, nano-Cu was found to hamper fetal development; however, the toxicity of nano-Cu and its effects in placental function have not been elucidated. Therefore, we investigated the toxic effects of nano-Cu using rat placenta. Pregnant Sprague-Dawley rats were orally exposed to different copper sources from the third day of gestation (GD 3) to GD 18. We found that nano-Cu (180 mg/kg) and CuCl2.2 H2O increased the accumulation of copper. Besides, nano-Cu and CuCl2.2 H2O disrupted the placental morphology and induced oxidative stress. Micro-copper (micro-Cu) caused similar toxicity in the placenta, but its effects were weaker than that of nano-Cu and CuCl2.2 H2O. In addition, exposure to nano-Cu (180 mg/kg) and CuCl2.2 H2O induced inflammation in the rat placenta. Furthermore, nano-Cu, micro-Cu, and CuCl2.2 H2O upregulated the expression of the autophagy-related proteins, Beclin-1 and LC3 II/ LC3 I, and downregulated that of p62. Moreover, nano-Cu, micro-Cu, and CuCl2.2 H2O downregulated the protein expression of PI3K, p-AKT/AKT, and p-mTOR/mTOR in rat placentas, whereas the protein expression of p-AMPK/AMPK was upregulated. Taken together, our data indicated that prenatal exposure to nano-Cu induced autophagy via the PI3K/AKT/mTOR and AMPK/mTOR pathways, which associated with oxidative stress and inflammation in rat placenta.

Epigallocatechin-3-gallate reduces liver and immune system damage in Acinetobacter baumannii-loaded mice with restraint stress.

AIM: Due to the significant increase in the antimicrobial resistance of Acinetobacter baumannii (A. baumannii), new drugs to block the progression of infection are strongly needed. Epigallocatechin-3-gallate (EGCG), a major component of green tea, has exhibited potential activity against A. baumannii in vitro. The aim of this study was to determine if EGCG could be used for pretreating stress-related effects, liver damage, and immune dysfunction caused by A. baumannii infection in vivo. METHODS: Levels of stress hormones, oxidative stress, liver damage, and immune components were analyzed in a murine infection model in which the mice were pretreated with EGCG for one week then intranasally inoculated with A. baumannii. The mice were restrained for 12 h to promote infection because A. baumannii is an opportunistic pathogen. The pretreatment efficacy of EGCG against A. baumannii in mice was assessed for 24 h after the bacterial infection. RESULTS: Restraint stress strengthened the damage from the A. baumannii infection. Pretreatment with EGCG in the murine pneumonia model markedly reduced stress hormones, oxidative metabolites, and proinflammatory cytokine production. EGCG also increased the immune function by increasing the levels of sIgA, T cells and neutrophils after infection. Moreover, pretreatment with EGCG significantly decreased the liver damage by inhibiting the levels of transaminases, oxidative stress metabolites, and cytokines, while maintaining the normal activity of CYP450 enzymes in the liver. CONCLUSION: EGCG was efficacious as a preventative treatment for the damage seen in an experimental model of A. baumannii infection.

Oral exposure of pregnant rats to copper nanoparticles caused nutritional imbalance and liver dysfunction in fetus.

Copper nanoparticles (Cu NPs) are increasingly used as an animal feed additive in China. In previous studies, it was determined that Cu NPs can penetrate the placental barrier, however, its toxic effects on the fetus have not yet been elucidated. Therefore, in this study, we investigated the potential fetal toxic effects of Cu NPs. Cu NPs were orally administered to pregnant Sprague-Dawley rats from gestation days (GDs) 3-18 at a dose of 60, 120, and 180 mg/kg/day. Cesarean sections were conducted on GD 19. During fetal examination, no toxicities were observed regarding general clinical signs, however, Cu NPs significantly decreased fetal body weight, body length, and liver weights. Cu ions and Cu MPs exhibited similar effects on the fetal development. Cu NPs increased the liver concentration of Cu, and decreased protein levels and Fe in fetuses. Cu NPs also increased oxidative stress and inflammation in the fetus after pregnant rats were exposed to high doses of Cu NPs. Oral exposure to Cu NPs during pregnancy increased Cu concentrations in the fetus, which not only affected fetal development, but also significantly induced oxidative stress and inflammatory responses in fetal liver. Taken together, these findings are valuable to evaluate fetal risk assessment after oral exposure of Cu NPs during pregnancy. Additional comprehensive toxicity studies are deemed necessary to clarify the underlying mechanisms involved.

Epigallocatechin-3-gallate protects immunity and liver drug-metabolism function in mice loaded with restraint stress.

(-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic compound present in green tea and has been shown to possess bio-activities. In this study, we investigated the protective effects of EGCG against restraint stress (RS)-induced liver injury and immunosuppression. EGCG (10, 20 and 40 mg/kg) was orally administered to mice daily for 7 days before modeling the restraint stress. lood, liver and broncho-alveolar lavage fluid (BALF) samples were collected and tested. We found that EGCG significantly reduced the release of stress hormones to weak restraint stress response. EGCG effectively improved hepatic damage by decreas the serum levels of alanine aminotransaminase (ALT) and aspartate transaminase (AST) in restraint-challenged mice. Furthermore, EGCG also significantly prevented the release of H2O2, NOS and 8-isoprostane, and reduced the levels of interleukin (IL)-1ß, IL-2,and IL-6 restrained mice. EGCG can normal the level of cytochrome P450 (CYP450) 1A2, 2D22, 2E1 and 3A11 that induced by restraint stress., the inhibition status of T cells subsets in serum and gA in BALF were significantly relieved EGCG pretreatment. Taken together, our data suggest that EGCG possesse hepatic- and immune-protective properties against restraint stress through its anti-oxidant, anti-inflammatory and immunomodulatory activities.