Display omitted
•NK relieved DSS-induced chronic colitis.•NK maintained mucosal integrity by inhibiting apoptosis.•NK regulated gut microbiota of DSS-induced chronic colitis.•NK suppressed Trp ...metabolism via inhibiting IDO-1 in DSS-induced chronic colitis.
In this study, we investigated the protective effect of Nattokinase (NK), the most active ingredient in natto used for healthcare, on dextran sulfate sodium (DSS)-induced chronic colitis and unraveled the potential mechanisms. NK dramatically attenuated clinical symptoms and pathological damage of DSS-induced chronic colitis. NK also inhibited proinflammatory cytokines production in DSS-induced colonic tissues. Mucosal integrity was maintained by NK. Moreover, nattokinase reversed DSS-induced decline of bacteria community diversity and intestinal microbial imbalance by decreasing levels of Firmicutes and increasing levels of Bacteroidetes. Tryptophan (Trp) metabolism analysis demonstrated that NK suppressed Trp catabolism especially the Kynurenine (Kyn) pathway in chronic colitis. Furthermore, NK strikingly down-regulated the protein expression of IDO-1 in chronic colitis mice. Taken together, the study demonstrated that NK relieved DSS-induced chronic colitis by regulating gut microbiota and suppressing Trp metabolism via inhibiting IDO-1. This study indicated that NK might be a promising and effective agent for IBD.
Limonin, a bioactive compound from citrus plants, exerts antioxidant activities, however its therapeutic potential in acetaminophen (APAP)-induced hepatotoxicity remains unclear.
Our study aims to ...investigate the protective effect of limonin on APAP-induced hepatotoxicity and illuminate the underlying mechanisms.
design In vitro, we chose L-02 cells to establish in vitro APAP-induced liver injury model. L-02 cells were treated with APAP (7.5 mM) for 24 h after pre-incubation with limonin (10, 25, 50 μM) or NAC (250 μM) for 2 h. In vivo, we used C57BL/6 mice as an in vivo APAP-induced liver injury model. C57BL/6 mice with pre-treatment of limonin (40, 80 mg/kg) or NAC (150 mg/kg) for 1 h, were given with a single dose of APAP (300 mg/kg).
After pre-incubation with limonin (10, 25, 50 μM) for 2 h, L-02 cells were treated with APAP (7.5 mM) for 24 h.The experiments in vitro included MTT assay, Annexin V/PI staining, measurement of reactive oxygen species (ROS), quantitative real-time PCR analysis, Western blot analysis, immunofluorescence microscopy and analysis of LDH activity. Transfection of Nrf2 or Sirt1 siRNA was also conducted in vitro. In vivo, C57BL/6 mice with pre-treatment of limonin (40, 80 mg/kg) or NAC (150 mg/kg) for 1 h, were given with a single dose of APAP (300 mg/kg). Mice were sacrificed at 4, 12 h after APAP poisoning, and analysis of ALT and AST in serum, GSH level in liver tissues, liver histological observation and immunohistochemistry were performed.
Limonin increased the cell viability and alleviated APAP-induced apoptosis in hepatocytes. Limonin also inhibited APAP-induced mitochondrial-mediated apoptosis by decreasing the ratio of Bax/Bcl-2, recovery of mitochondrial membrane potential (MMP), inhibiting ROS production and cleavage of caspase-3 in L-02 cells. Moreover, limonin induced activation of Nrf2 and increased protein expression and mRNA levels of its downstream targets, including HO-1, NQO1 and GCLC/GCLM. The inhibition of limonin on apoptosis and promotion on Nrf2 antioxidative pathway were lessened after the application of Nrf2 siRNA. In addition, limonin inhibited NF-κB transcriptional activation, NF-κB-regulated genes and protein expression of inflammatory related proteins iNOS and COX2. Furthermore, limonin increased the protein expression of Sirt1. Sirt1 siRNA transfection confirmed that limonin activated Nrf2 antioxidative pathway and inhibited NF-κB inflammatory response by upregulating Sirt1. Finally, we established APAP-induced liver injury in vivo and demonstrated that limonin alleviated APAP-induced hepatotoxicity by activating Nrf2 antioxidative signals and inhibiting NF-κB inflammatory response via upregulating Sirt1.
In summary, this study documented that limonin mitigated APAP-induced hepatotoxicity by activating Nrf2 antioxidative pathway and inhibiting NF-κB inflammatory response via upregulating Sirt1, and demonstrated that limonin had therapeutic promise in APAP-induced liver injury.
Display omitted
Metastatic osteosarcoma usually has an unsatisfactory response to the current standard chemotherapy and causes poor prognosis. Currently, epithelial-mesenchymal transition (EMT) is reported as a ...critical event in osteosarcoma metastasis. Glaucocalyxin A, a bioactive ent-kauranoid diterpenoid, exerts anti-cancer effect on osteosarcoma by inducing apoptosis in previous study. However, the effect of Glaucocalyxin A on EMT and metastasis of osteosarcoma is unclear. In this study, we investigated the potential mechanisms of Glaucocalyxin A on EMT and metastasis of osteosarcoma. We found that Glaucocalyxin A inhibited migration and invasion of MG-63 and 143B cells. Moreover, Glaucocalyxin A increased the protein and mRNA levels of E-cadherin and decreased the protein and transcription expression of N-cadherin, Vimentin. Glaucocalyxin A also inhibited the protein and mRNA levels of EMT-associated transcription factor including Snail and Slug. Furthermore, Glaucocalyxin A inhibited transforming growth factor-β1 (TGF-β1)-induced migration, invasion and EMT of low-metastatic osteosarcoma U2OS cells. Glaucocalyxin A inhibited TGF-β-induced phosphorylation of Smad 2/3 in osteosarcoma U2OS cells. Finally, we established transplanted metastatic models of highly metastatic osteosarcoma 143B cells. Glaucocalyxin A inhibited lung metastasis in vivo. Interestingly, Glaucocalyxin A increased the protein expression of E-cadherin and reduced the protein expression of N-cadherin and Vimentin. Glaucocalyxin A inhibited the protein expression of Snail and Slug in vivo. In summary, this study demonstrated that Glaucocalyxin A inhibited EMT and TGF-β1-induced EMT by inhibiting TGF-β1/Smad2/3 signaling pathway in osteosarcoma. Therefore, Glaucocalyxin A might be a promising candidate against the metastasis of human osteosarcoma.
•Glaucocalyxin A reverses epithelial-mesenchymal transition (EMT) in osteosarcoma.•Glaucocalyxin A prevents TGF-β1-induced EMT by inhibiting Smad2/3 pathway in osteosarcoma.•Glaucocalyxin A inhibits osteosarcoma metastasis to lung in the metastatic model.
Lipopolysaccharide (LPS)-induced liver injury is the main factor in acute liver failure. The current study aims to investigate the protection of limonin, an antioxidant compound from citrus fruit, ...against LPS-induced liver toxicity and elucidate the potential mechanisms. We found that limonin elevated cell viability and reduced LDH release in LPS-treated HepG2 cells. Limonin also inhibited LPS-induced pyroptosis by inhibiting membrane rupture, reducing ROS generation, and decreasing gasdermin D activation. Moreover, limonin inhibited the formation of a NOD-like receptor protein 3 (NLRP3)/Apoptosis-associated speck-like protein containing a CARD (ASC) complex by reducing the related protein expression and the colocalization cytosolic of NLRP3 and caspase-1 and then suppressed IL-1β maturation. Ultimately, we established LPS-induced hepatotoxicity in vivo by using C57BL/6 mice administrated LPS (10 mg/kg) intraperitoneally and limonin (50 and 100 mg/kg) orally. We found that limonin dereased the serum ALT and AST activity and LDH release and increased the hepatic GSH amount in LPS-treated mice. Additionally, the liver histological evaluation revealed that limonin protects against LPS-induced liver damage. We further demonstrated that limonin ameliorated LPS-induced hepatotoxicity by inhibiting pyroptosis via the NLRP3/gasdermin D signaling pathway. In summary, this study uncovered the mechanism whereby limonin mitigated LPS-induced hepatotoxicity and documented that limonin might be a promising candidate drug for LPS-induced hepatotoxicity.
Display omitted
•Limonin relieved the severity of DSS-induced chronic colitis in mice.•Limonin attenuated DSS-induced chronic colitis by inhibiting PERK-ATF4-CHOP pathway of endoplasmic reticulum ...(ER) stress.•Limonin attenuated DSS-induced chronic colitis by inhibiting NF-κB signaling.•Limonin suppressed PERK-ATF4-CHOP pathway of ER stress and NF-κB signaling in LPS-induced inflammation in vitro.
Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammation regulated by intricate mechanisms. Limonin, a natural tetracyclic triterpenoid compound, possesses multiple bioactivities including anti-inflammation, anti-cancer and so on. However, the therapeutic potential and the underlying mechanism of limonin on IBD remain unclear. Here, we probe into the effect of limonin on chronic colitis induced by dextran sulfate sodium (DSS) and illustrated the potential mechanisms. We found that limonin relieved the risk and severity of DSS-induced chronic colitis in mice through various aspects including increasing body weight and colon length, decreasing the mortality rate, inhibiting MPO activity and improving colon pathology. Limonin also decreased the production of proinflammatory cytokines TNF-α, IL-1β, IL-6 and the expression of inflammatory proteins COX-2, iNOS in colon tissues from DSS-induced colitis mice. Moreover, limonin attenuated DSS-induced chronic colitis by inhibiting PERK-ATF4-CHOP pathway of endoplasmic reticulum (ER) stress and NF-κB signaling. In vitro, limonin not only decreased LPS-induced higher production of pro-inflammatory cytokines and inflammatory proteins mentioned above by inhibiting NF-κB signaling in macrophage cells RAW264.7, but also suppressed PERK-ATF4-CHOP pathway of ER stress. In summary, our study demonstrated that limonin mitigated DSS-induced chronic colitis via inhibiting PERK-ATF4-CHOP pathway of ER stress and NF-κB signaling. All of this study provides the possibility for limonin as an effective drug for chronic colitis of IBD in the future.
Based on pollen records in B-3GC gravity core, environmental change since 9500 aBP of Okinawa Trough and its adjacent islands was derived. The result showed that the most time during this period was ...in a warm temperate climate except in middle Holocene (6800-4400 aBP) that was under subtropical climate control. During 9500–8300 aBP and 3100–2000 aBP periods, it appeared colder and drier than the rest time. The original area of pollen sources surrounding Okinawa Trough was covered by evergreen and deciduous broadleaf forest alternatively with mixed broad-leaf-conifer forest distributed in high mountainous areas. Usually, these three kinds of forests existed at the same time with difference in altitude. Pollen from subtropical and tropical plants increased obviously in about 5000–6000 aBP, reflecting a great lifting of vegetation zone and expansion of evergreen broad-leaf forest in the study area. However, there was a slight descending of plant zone and shrinking of evergreen broadleaf forest during 9500-8300 aBP and 3000-2000 aBP. During the remaining periods vegetation zone was higher than the present but in a limited range.
The training set of a universal near infrared （NIR） model for quantitative analysis of a drug should cover as many samples of this drug in the market as possible. Inevitably the model may fail for ...new products that have different excipients and produc- tion processes. In such circumstances the model should be updated. We here propose a new strategy to iteratively update a universal NIR quantitative model for azithromycin. We prove that universal quantitative models generated from this new strategy are comparably effective for azithromycin injection powders and azithromycin tablets, compared to the strategy using hierarchical clustering method which we reported previously. Furthermore, we establish the correlation coefficient r between a new sample and the training set samples can be used to decide whether or not the model should be updated.
Psoralea corylifolia L., (P. corylifolia), which is used for treating vitiligo in clinic, shows inhibitory and activating effects on tyrosinase, a rate-limiting enzyme of melanogenesis. This study ...aimed to determine the active ingredients in the ethenal extracts of P. corylifolia on tyrosinase activity. The spectrum-effect relationship and knock-out method were established to predict the active compounds. Their structures were then identified with the high resolution mass spectra. A high performance liquid chromatography method was established to obtain the specific chromatograms. Tyrosinase activity in vitro was assayed by the method of oxidation rate of levodopa. Partial least squares method was used to test the spectrum-effect relationships. Chromatographic peaks P2, P4, P9, P10, P11, P13, P21, P26, P28, and P30 were positively related to the activating effects on tyrosinase activity in PE, whereas chromatographic peaks P1, P3, P6, P14, P16, P19, P22, and P29 were negatively related to the activating effects on tyrosinase in the P. corylifolia (PEs). When the sample concentration was 0.5 g·mL−1, equal to the amount of raw medicinal herbs, the target components were daidzein (P2), psoralen (P5), neobavaisoflavone (P13), and psoralidin (P20), which were consistent with the results of spectrum-effect relationships.
•The characteristics of impurities in macrolides were summarized to guide the impurity analysis of this class of drugs.•Three separate LC-ESI–MS/MS methods were developed to investigate impurities in ...the three 16-membered ring macrolides.•A QSRR model was constructed by MLR to predict the retention times of identified impurities which were not detected–MS methods without obtaining their reference standards.
Macrolides are multicomponent drugs whose impurity control is always a challenge demanding analysis method with good sensitivity and selectivity. Three separate, sensitive, accurate liquid chromatography tandem mass spectrometry methods (LC–MS) were developed for the measurement of three 16-membered ring macrolides (josamycin, josamycin propionate and midecamycin acetate) and related substances in commercial samples. The characteristics of impurities in macrolides were summarized as useful guidance for the impurity analysis of this class of drugs. For each drug, a large number of unknown components have been detected with the high-sensitive MS detector and possible structures of the majority of them were postulated based on the summarized fragmentation rules of 16-membered ring macrolides. A QSRR model was constructed by multilinear regression to predict the retention times of identified impurities which were not detected by the LC–MS methods, without obtaining their reference standards. Satisfactory performance was obtained during leave-one-out cross-validation with a predictive ability (Q2) of 0.95. The generalisation ability of the model was further confirmed by an average error of 2.3% in external prediction. The best QSRR model, based on eight molecular descriptors, exhibited a promising predictive performance and robustness.
In late September 2019, the longest and most extensive ozone (O3) pollution process occurred at Pearl River Delta. Base on the observational data, surface-level O3, vertical distribution ...characteristics boundary layer O3 as well as its effect on surface-level O3 are thoroughly analyzed. The O3 lidar results showed similar vertical O3 profiles both in pollution episodes and clean periods, from which a high O3 concentration layer between 300 and 500 m and a sub-high O3 concentration layer between 1300 and 1700 m (near the top of the mixing layer) can be found. Besides, the downward O3 transport paths from the high/sub-high O3 concentration layers could be observed along with the boundary layer evolution: At nighttime, large amounts of O3 were effectively stored into the residual layer (RL). Due to the upward development of Mixing layer (ML) in early morning, atmospheric vertical mixing carried the O3 inside the RL down to the surface, which led to a rapid increase in the surface-level O3. The sub-high O3 layer began the downward mixing at noon, and became well-mixed after the boundary layer was fully developed in the afternoon, by which the near surface O3 pollution deteriorated again. Further analysis of the heavy O3 pollution episodes show that, the high O3 concentration inside the RL contributed 54% ± 6% of the surface-level O3 at 9:00 LT and the average contribution of O3 in the sub-high concentration layer to the surface-level O3 at 14:00 LT was 26% ± 9%. Based on the quantitative analysis of the observational data, this paper focus to reveal the importance of the contribution of O3 inside the RL and near the top of the ML to the surface O3.
Display omitted
•High and sub-high ozone concentration layers are observed in the range of 300-500 m and 1300-1700 m height above the ground in Shenzhen.•The vertical ozone distribution characteristics in the mixing layer in daytime and the residual layer in nighttime are significantly different.•The nocturnal residual layer stores the ozone and has a remarkable impact on the surface ozone concentration on the next day.
PDF
