Epigallocatechin-3-gallate mitigates cadmium-induced intestinal damage through modulation of the microbiota-tryptophan-aryl hydrocarbon receptor pathway.

Early studies have shown that the gut microbiota is a critical target during cadmium exposure. The prebiotic activity of epigallocatechin-3-gallate (EGCG) plays an essential role in treating intestinal inflammation and damage. However, the exact intestinal barrier protection mechanism of EGCG against cadmium exposure remains unclear. In this experiment, four-week-old mice were exposed to cadmium (5 mg kg-1) for four weeks. Through 16 S rDNA analysis, we found that cadmium disrupted the gut microbiota and inhibited the indole metabolism pathway of tryptophan (TRP), which serves as the principal microbial production route for endogenous ligands to activate the aryl hydrocarbon receptor (AhR). Additionally, cadmium downregulated the intestinal AhR signaling pathway and harmed the intestinal barrier function. Treatment with EGCG (20 mg kg-1) and the AhR agonist 6-Formylindolo[3,2-b] carbazole (FICZ) (1 µg/d) significantly activated the AhR pathway and alleviated intestinal barrier injury. Notably, EGCG partially restored the gut microbiota and upregulated the TRP-indole metabolism pathway to increase the level of indole-related AhR agonists. Our findings demonstrate that cadmium dysregulates common gut microbiota to disrupt TRP metabolism, impairing the AhR signaling pathway and intestinal barrier. EGCG reduces cadmium-induced intestinal functional impairment by intervening in the intestinal microbiota to metabolize AhR agonists. This study offers insights into the toxic mechanisms of environmental cadmium and a potential mechanism to protect the intestinal barrier with EGCG.

Elucidating the Mechanism of Action of the Gram-Negative-Pathogen-Selective Cyclic Antimicrobial Lipopeptide Brevicidine.

Due to the accelerated appearance of antimicrobial-resistant (AMR) pathogens in clinical infections, new first-in-class antibiotics, operating via novel modes of action, are desperately needed. Brevicidine, a bacterial nonribosomally produced cyclic lipopeptide, has shown potent and selective antimicrobial activity against Gram-negative pathogens. However, before our investigations, little was known about how brevicidine exerts its potent bactericidal effect against Gram-negative pathogens. In this study, we find that brevicidine has potent antimicrobial activity against AMR Enterobacteriaceae pathogens, with MIC values ranging between 0.5 µM (0.8 mg/L) and 2 µM (3.0 mg/L). In addition, brevicidine showed potent antibiofilm activity against the Enterobacteriaceae pathogens, with the same 100% inhibition and 100% eradication concentration of 4 µM (6.1 mg/L). Further mechanistic studies showed that brevicidine exerts its potent bactericidal activity by interacting with lipopolysaccharide in the outer membrane, targeting phosphatidylglycerol and cardiolipin in the inner membrane, and dissipating the proton motive force of bacteria. This results in metabolic perturbation, including the inhibition of ATP synthesis; the inhibition of the dehydrogenation of NADH; the accumulation of reactive oxygen species in bacteria; and the inhibition of protein synthesis. Finally, brevicidine showed a good therapeutic effect in a mouse peritonitis-sepsis model. Our findings pave the way for further research on the clinical applications of brevicidine to combat prevalent infections caused by AMR Gram-negative pathogens worldwide.

Structural and pharmacological diversity of 1,4-naphthoquinone glycosides in recent 20 years.

1,4-naphthoquinones are the most widespread naphthoquinone compounds. Recently, many 1,4-naphthoquinone glycosides with different structural features have been obtained from both nature and synthesis, which has led to an increasing variety of naphthoquinone glycosides. In this paper, the structure variety and biological activity in recent 20 years are reviewed, and classified them according to the source and structure characteristics. Meanwhile the synthetic methods of O-, S-, C- and N-naphthoquinone glycosides and their structure activity relationships are also described. It was referred that the presence of polar groups of C2 and C5 and non-polar groups attached to C3 on the naphthoquinone ring are beneficial for their biological activities. It will provide more comprehensive literature resources for the future research of 1, 4-naphthoquinone glycosides and lay a theoretical foundation.

Research progress on the structure and biological diversities of 2-phenylindole derivatives in recent 20 years.

The privileged structure binds to multiple receptors with high affinity, which is helpful to the development of new bioactive compounds. Indole is classified as a privileged structure, which may be one of the most important structural categories in drug discovery. As a special subset of indole compounds, 2-phenylindole seems to be one of most promising forerunners of drug development. In this paper, 106 articles were referenced to review the structural changes, biological activities and structure-activity relationship of compounds in recent 20 years, and classified them according to their pharmacological activities, from several aspects, including anticancer, antibacterial, anti-inflammatory, analgesic, antiviral, anti-parasite, the biological activities target to central nervous system, et al. It also points out the importance of artificial intelligence (AI) technology in discovery of new 2-phenylindole compounds in a broader prospect. This review will provide some ideas for researchers to develop new indole drugs.

Synthesis of structurally diverse derivatives of aconitine-type diterpenoid alkaloids and their anti-proliferative effects on canine breast cancer cells.

As one of the most common malignancies in female dogs, no drugs have been developed specifically for the treatment of canine mammary carcinoma. In our previous study, a series of diterpenoid alkaloids derivatives were synthesized and exhibited good anti-proliferative activity in vitro against both normal and adriamycin-resistant human breast cancer cells lines. In this study, a series of structurally diverse aconitine-type alkaloids derivatives were also synthesized basing on the minimal modification principle, by modifying on A-ring, C-ring, D-ring, N-atom or salt formation on aconitine skeleton. Their anti-proliferative effects and mechanism on canine mammary cancer cells were investigated, exhibiting the importance of the substitution at A ring, the long chain ester at the C8, the hydroxyl group at the C13, the phenyl ring at the C14 and the N-ethyl group, while the methoxy group at the C1 and C16 showed little effect on the activity. The results of the proliferation, apoptosis and ultrastructure tests of the treated canine mammary carcinoma cells referred that the representative compound, aconitine linoleate (25) could block the cell cycle of canine mammary carcinoma cells in the G0/G1 phase, and exhibit the anti-proliferative effect by inducing apoptosis.

Isolation, structure identification, and immunostimulatory effects in vitro and in vivo of polysaccharides from Onosma hookeri Clarke var. longiforum Duthie.

BACKGROUND: This study characterized an acidic polysaccharide (OHC-LDPA) isolated from the medicinal and edible homologous plant Onosma hookeri Clarke var. longiforum Duthie. The structure of OHC-LDPA was elucidated based on the analysis of infrared, one-/two-dimensional nuclear magnetic resonance, and gas chromatography-mass spectrometry data. The immunostimulatory effects of OHC-LDPA were identified by both in vitro and in vivo models. RESULTS: The structure of OHC-LDPA was elucidated as a typical pectin polysaccharide, consisting of galacturonic acid, galactose, arabinose, and rhamnose as the primary sugars, with linear galacturonic acid as the main chain and arabinogalacturonic acid as the main branched components. OHC-LDPA could significantly stimulate the proliferation and phagocytosis of RAW264.7 macrophages and the release of nitric oxide in vitro. Also, it could accelerate the recovery of spleen and thymus indexes, enhance the splenic lymphocyte proliferation responses, and restore the levels of interleukin-2, interleukin-10, interferon-γ, and immunoglobulin G in the serum in a cyclophosphamide-induced immunosuppressed-mice model. In addition, OHC-LDPA could restore the intestinal mucosal immunity and reduce the inflammatory damage. CONCLUSION: OHC-LDPA could improve the immunity both in vitro and in vivo and could be used as a potential immunostimulant agent. © 2022 Society of Chemical Industry.

Nanocarriers for combating biofilms: Advantages and challenges.

Bacterial biofilms are highly resistant to antibiotics and pose a great threat to human and animal health. The control and removal of bacterial biofilms have become an important topic in the field of bacterial infectious diseases. Nanocarriers show great anti-biofilm potential because of their small particle size and strong permeability. In this review, the advantages of nanocarriers for combating biofilms are analysed. Nanocarriers can act on all stages of bacterial biofilm formation and diffusion. They can improve the scavenging effect of biofilm by targeting biofilm, destroying extracellular polymeric substances and enhancing the biofilm permeability of antimicrobial substances. Nanocarriers can also improve the antibacterial ability of antimicrobial drugs against bacteria in biofilm by protecting the loaded drugs and controlling the release of antimicrobial substances. Additionally, we emphasize the challenges faced in using nanocarrier formulations and translating them from a preclinical level to a clinical setting.

Autophagy and apoptosis mediated nano-copper-induced testicular damage.

Nano-copper has been increasingly employed in various products. In previous studies, we showed that nano-copper caused damage in the rat testis, but it remains unclear whether the toxic reaction can affect the reproductive function. In this study, following 28 d of exposure to nano-copper at a dose of 44, 88, and 175 mg/kg/day, there was a decrease in sperm quality, fructose content, and the secretion of sex hormones. Nano-copper also increased the level of oxidative stress, sperm malformation rate, and induced abnormal structural changes in testicular tissue. Moreover, Nano-copper upregulated the expression of apoptosis-related protein Bax and autophagy-related protein Beclin, and downregulated the expression of Bcl2 and p62. Furthermore, nano-copper (175 mg/kg) downregulated the protein expression of AMPK, p-AKT, mTOR, p-mTOR, p-4E-BP1, p70S6K, and p-p70S6K, and upregulated the protein expression of p-AMPK. Therefore, nano-copper induced damage in testicular tissues and spermatogenesis is highly related to cell apoptosis and autophagy by regulating the Akt/mTOR signaling pathway. In summary, excess exposure to nano-copper may induce testicular apoptosis and autophagy through AKT/mTOR signaling pathways, and damage the reproductive system in adult males, which is associated with oxidative stress in the testes.

Antibacterial Peptide NP-6 Affects Staphylococcus aureus by Multiple Modes of Action.

Our previous study extracted and identified an antibacterial peptide that was named NP-6. Herein, we investigated the physicochemical properties of NP-6, and elucidated the mechanisms underlying its antimicrobial activity against Staphylococcus aureus. The results showed that the hemolysis activity of NP-6 was 2.39 ± 0.13%, lower than Nisin A (3.91 ± 0.43%) at the same concentration (512 µg/mL). Negligible cytotoxicity towards RAW264.7 cells was found when the concentration of NP-6 was lower than 512 µg/mL. In addition, it could keep most of its activity in fetal bovine serum. Moreover, transmission electron microscopy, confocal laser scanning microscopy, and flow cytometry results showed that NP-6 can destroy the integrity of the bacterial cell membrane and increase the membrane permeability. Meanwhile, NP-6 had binding activity with bacterial DNA and RNA in vitro and strongly inhibited the intracellular ß-galactosidase activity of S. aureus. Our findings suggest that NP-6 could be a promising candidate against S. aureus.

Adsorption Behavior of 3-phenoxybenzoic Acid by Lactobacillus Plantarum and Its Potential Application in Simulated Digestive Juices.

3-PBA is a major degradation intermediate of pyrethroids. Its widespread existence in the environment poses a severe threat to the ecosystem and human health. This study evaluated the adsorption capacity of L. plantarum RS20 toward 3-PBA. Batch adsorption experiments indicated that the optimal adsorption conditions were a temperature of 37 °C and initial pH of 6.0-8.0, under which the removal rate was positively correlated with the cell concentration. In addition, there was no link between the incubation time and adsorption rate. The kinetic study showed that the adsorption process fitted well with the pseudo-second-order model, and the adsorption isotherms could be described by both Langmuir and Freundlich equations. Heat and acid treatments showed that the ability of strain RS20 in removing 3-PBA was independent of microbial vitality. Indeed, it was involved with chemisorption and physisorption via the cell walls. The cell walls made the highest contribution to 3-PBA removal, according to the adsorption experiments using different cellular components. This finding was further reconfirmed by SEM. FTIR spectroscopy analysis indicated that carboxyl, hydroxyl, amino groups, and -C-N were the functional sites for the binding of 3-PBA. The co-culture experiments showed that the adsorption of strain RS20 enhanced the degradation of 3-PBA by strain SC-1. Strain RS20 could also survive and effectively remove 3-PBA in simulated digestive juices. Collectively, strain RS20 could be employed as a biological detoxification agent for humans and animals by eliminating 3-PBA from foods, feeds, and the digestive tract in the future.

The Antivirulence Activity of Umbelliferone and Its Protective Effect against A. hydrophila-Infected Grass Carp.

A. hydrophila is an important pathogen that mainly harms aquatic animals and has exhibited resistance to a variety of antibiotics. Here, to seek an effective alternative for antibiotics, the effects of umbelliferone (UM) at sub-MICs on A. hydrophila virulence factors and the quorum-sensing system were studied. Subsequently, RNA sequencing was employed to explore the potential mechanisms for the antivirulence activity of umbelliferone. Meanwhile, the protective effect of umbelliferone on grass carp infected with A. hydrophila was studied in vivo. Our results indicated that umbelliferone could significantly inhibit A. hydrophila virulence such as hemolysis, biofilm formation, swimming and swarming motility, and their quorum-sensing signals AHL and AI-2. Transcriptomic analysis showed that umbelliferone downregulated expression levels of genes related to exotoxin, the secretory system (T2SS and T6SS), iron uptake, etc. Animal studies demonstrated that umbelliferone could significantly improve the survival of grass carps infected with A. hydrophila, reduce the bacterial load in the various tissues, and ameliorate cardiac, splenic, and hepatopancreas injury. Collectively, umbelliferone can reduce the pathogenicity of A. hydrophila and is a potential drug for treating A. hydrophila infection.

The Antiviral Activity of Caprylic Monoglyceride against Porcine Reproductive and Respiratory Syndrome Virus In Vitro and In Vivo.

Porcine reproductive and respiratory syndrome (PRRS) is a disease with a major economic impact in the global pig industry, and this study aims to identify potential anti-PRRSV drugs. We examined the cytotoxicity of four medium-chain fatty acids (MCFAs) (caprylic, caprylic monoglyceride, decanoic monoglyceride, and monolaurin) and their inhibition rate against PRRSV. Then the MCFAs with the best anti-PRRSV effect in in vitro assays were selected for subsequent in vivo experiments. Potential anti-PRRSV drugs were evaluated by viral load assay, pathological assay, and cytokine level determination. The results showed that caprylic monoglyceride (CMG) was the least toxic to cells of the four MCFAs, while it had the highest PRRSV inhibition rate. Then the animals were divided into a low-CMG group, a medium-CMG group, and a high-CMG group to conduct the in vivo evaluation. The results indicated that piglets treated with higher concentrations of caprylic monoglyceride were associated with lower mortality and lower viral load after PRRSV infection (p < 0.05). The pulmonary pathology of the piglets also improved after CMG treatment. The levels of pro-inflammatory cytokines (IL-6, IL-8, IL-1ß, IFN-γ, TNF-α) were significantly downregulated, and the levels of anti-inflammatory cytokine (IL-10) were significantly upregulated in the CMG-treated piglets compared to the positive control group (p < 0.05). Taken together, the present study revealed for the first time that caprylic monoglyceride has strong antiviral activity against PRRSV in vitro and in vivo, suggesting that caprylic monoglyceride could potentially be used as a drug to treat PRRS infection.

Resveratrol regulates intestinal barrier function in cyclophosphamide-induced immunosuppressed mice.

BACKGROUND: Resveratrol, a kind of polyphenolic phytoalexin, can be obtained from numerous natural foods. Although resveratrol is demonstrated to have various bioactivities, little is known about the regulation of intestinal barrier function under immunosuppression. The present study is aimed at investigating the regulatory effect of resveratrol on intestinal barrier function in immunosuppression in mice induced by cyclophosphamide. RESULTS: The effects of resveratrol on intestinal biological barrier were evaluated by 16S rRNA and metagenome sequencing analysis. The results showed that resveratrol could improve diversity of the intestinal microbiota and intestinal flora structure by increasing the abundance of probiotics, and resveratrol regulated the function of gut microbiota to resist immunosuppression. Resveratrol could significantly upregulate the secretion of secretory immunoglobulin A and promote the transcriptional levels of test cytokines, including tumor necrosis factor α, interferon γ, interleukin 4 and interleukin 6 in jejunum and ileum mucosa, suggesting improved intestinal immune barrier by resveratrol. The mRNA and protein levels of tight junction proteins involved in intestinal physical barrier function, including zonula occludens 1 (ZO-1), claudin 1 and occludin, were increased after resveratrol treatment. The protein levels of toll-like receptor 4 (TLR4), phosphorylation nuclear factor kappa-B (NF-κB-p65) and inhibitor of nuclear factor kappa-B kinase α were decreased by resveratrol treatment when compared with the untreated group, indicating inhibition of the TLR4/NF-ĸB signaling pathway. CONCLUSION: These results provide new insights into regulation of the intestinal barrier function by resveratrol under immunosuppression and potential applications of resveratrol in recovering intestinal function. © 2021 Society of Chemical Industry.

TGF-ß1-induced EMT activation via both Smad-dependent and MAPK signaling pathways in Cu-induced pulmonary fibrosis.

Copper (Cu) is considered as an essential trace element for living organisms. However, over-exposure to Cu can lead to adverse health effects on human and animals. There are limited researches on pulmonary toxicity induced by Cu. Here, we found that copper sulfate (CuSO4)-treatment could induce pulmonary fibrosis with Masson staining and up-regulated protein and mRNA expression of Collagen I and α-Smooth Muscle Actin (α-SMA) in mice. Next, the mechanism underlying Cu-induced pulmonary fibrosis was explored, including transforming growth factor-ß1 (TGF-ß1)-mediated Smad pathway, mitogen-activated protein kinases (MAPKs) pathway and epithelial-mesenchymal transition (EMT). CuSO4 triggered pulmonary fibrosis by activation of the TGF-ß1/Smad pathway, which was accomplished by increasing TGF-ß1, p-Smad2 and p-Smad3 protein and mRNA expression levels. Also, up-regulated protein and mRNA expression of p-JNK, p-ERK, and p-p38 demonstrated that CuSO4 activated MAPKs pathways. Concurrently, EMT was activated by increasing vimentin and N-cadherin while decreasing E-cadherin protein and mRNA expression levels. Altogether, the abovementioned findings indicate that CuSO4 treatment may induce pulmonary fibrosis through the activation of EMT induced by TGF-ß1/Smad pathway and MAPKs pathways, revealing the mechanism Cu-caused pulmonary toxicity.

Antimicrobial resistance and genotyping of Staphylococcus aureus obtained from food animals in Sichuan Province, China.

BACKGROUND: Staphylococcus aureus (S. aureus), especially methicillin-resistant Staphylococcus aureus (MRSA), is considered a common zoonotic pathogen, causing severe infections. The objective of this study was to investigate the antimicrobial susceptibility, resistance genes and molecular epidemiology among MRSA and methicillin-susceptible Staphylococcus aureus (MSSA) isolated from food animals in Sichuan Province, China. METHODS: This study was conducted on 236 S. aureus isolates. All isolates were subjected to antimicrobial susceptibility testing by using a standard microbroth dilution method. The Polymerase Chain Reaction (PCR) was performed to identify genes encoding the ß-lactams resistance (blaZ, mecA), macrolides (ermA, ermB, ermC) and aminoglycosides (aacA-aphD). The molecular structures and genomic relatedness of MRSA isolates were determined by staphylococcal chromosome cassette mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE), respectively. RESULTS: Among 236 isolates, 24 (10.17 %) were recognized as MRSA. MRSA isolates showed different resistance rates to 11 antimicrobials ranging from 33.33 to 100 %, while for MSSA isolates the rates varied from 8.02 to 91.51 %. Multi-drug resistance phenotype was found in all MRSA isolates. The ermC gene encoding macrolides-lincosamides-streptogramin B was the most prevalent gene detected in 87.29 % of the S. aureus isolates, followed by ermB (83.05 %), blaZ (63.98 %), aacA-aphD (44.07 %), ermA (11.44 %) and mecA (11.02 %) genes. The prevalence of resistance genes in MRSA isolates was significantly higher than that of MSSA. Regarding the molecular morphology, SCCmec III (12/24, 50 %) was the most common SCCmec type. Furthermore, the PFGE typing showed that 24 MRSA were divided into 15 cluster groups (A to O), the major pulsotype J encompassed 25 % of MRSA isolates. CONCLUSIONS: The S. aureus isolates from food animals in Sichuan province of China have severe antimicrobials resistance with various resistance genes, especially MRSA isolates. Additionally, the genetic pool of MRSA isolates is diverse and complex, and further investigation is necessary.

The antiviral activity of kaempferol against pseudorabies virus in mice.

BACKGROUND: Pseudorabies virus (PRV), a member of the Alphaherpesviruses, is one of the most important pathogens that harm the global pig industry. Accumulated evidence indicated that PRV could infect humans under certain circumstances, inducing severe clinical symptoms such as acute human encephalitis. Currently, there are no antiviral drugs to treat PRV infections, and vaccines available only for swine could not provide full protection. Thus, new control measures are urgently needed. RESULTS: In the present study, kaempferol exhibited anti-PRV activity in mice through improving survival rate by 22.22 %, which was higher than acyclovir (Positive control) with the survival rate of 16.67 % at 6 days post infection (dpi); meanwhile, the survival rate was 0 % at 6 dpi in the infected-untreated group. Kaempferol could inhibit the virus replication in the brain, lung, kidney, heart and spleen, especially the viral gene copies were reduced by over 700-fold in the brain, which was further confirmed by immunohistochemical examination. The pathogenic changes induced by PRV infection in these organs were also alleviated. The transcription of the only immediate-early gene IE180 in the brain was significantly inhibited by kaempferol, leading to the decreased transcriptional levels of the early genes (EPO and TK). The expression of latency-associated transcript (LAT) was also inhibited in the brain, which suggested that kaempferol could inhibit PRV latency. Kaempferol-treatment could induce higher levels of IL-1ß, IL-4, IL-6, TNF-α and IFN-γ in the serum at 3 dpi which were then declined to normal levels at 5 dpi. CONCLUSIONS: These results suggested that kaempferol was expected to be a new alternative control measure for PRV 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.

Oxidative stress-mediated apoptosis and autophagy involved in Ni-induced nephrotoxicity in the mice.

As an extensively environmental pollution, Nickel (Ni) represents a serious hazard to human health. The present study focused on exploring the mechanism of Ni-mediated nephrotoxicity, such as apoptosis, autophagy and oxidative stress. In the current work, NiCl2 treatment could induce kidney damage. Meanwhile, NiCl2 treatment elevated ROS production and MDA content and suppressed the antioxidant activity, which was characterized by reducing T-AOC, CAT, SOD activity and GSH content. For investigating the role of oxidative stress on NiCl2-mediated nephrotoxicity, N-acetyl cysteine (NAC, effective antioxidant and free radical scavenger) was co-treated with NiCl2. The results showed that NAC significantly suppressed the NiCl2-mediated oxidative stress and mitigated NiCl2-induced the kidney damage. Then, whether oxidative stress-induced autophagy and apoptosis were involved in NiCl2-induced nephrotoxicity was explored. The findings demonstrated that NAC relieved NiCl2-induced autophagy and reversed the activation of Akt/AMPK/mTOR pathway. Concurrently, the results indicated that NAC attenuated NiCl2-induced apoptosis, as evidenced by reduction of apoptotic cells and cleaved-caspase-3/- 8/- 9 together with cleaved-PARP protein levels. To sum up, our findings suggested that NiCl2-mediated renal injury was associated with oxidative stress-induced apoptosis and autophagy. This study provides new theoretical basis for excess Ni exposure nephrotoxic researches.

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.

New pectic polysaccharides from Codonopsis pilosula and Codonopsis tangshen: structural characterization and cellular antioxidant activities.

BACKGROUND: Codonopsis pilosula and Codonopsis tangshen are plants widely used in traditional Chinese medicine. Two pectic polysaccharides from the roots of C. pilosula and C. tangshen named as CPP-1 and CTP-1 were obtained by boiling water extraction and column chromatography. RESULTS: The core structures of both CPP-1 and CTP-1 comprise the long homogalacturonan region (HG) as the backbone and the rhamnogalacturonan I (RG-I) region as the side chains. CPP-1 has methyl esterified galacturonic acid units and a slightly lower molecular weight than CTP-1. Biological testing suggested that CPP-1 and CTP-1 can protect IPEC-J2 cells against the H2 O2 -induced oxidative stress by up-regulating nuclear factor-erythroid 2-related factor 2 and related genes in IPEC-J2 cells. The different antioxidative activities of polysaccharides from different source of C. pilosula may be result of differences in their structures. CONCLUSION: All of the results indicated that pectic polysaccharides CPP-1 and CTP-1 from different species of C. pilosula roots could be used as a potential natural antioxidant source. These findings will be valuable for further studies and new applications of pectin-containing health products. © 2021 Society of Chemical Industry.