Limonin Attenuates LPS-Induced Hepatotoxicity by Inhibiting Pyroptosis via NLRP3/Gasdermin D Signaling Pathway.

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-1ß 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.

Limonin ameliorates dextran sulfate sodium-induced chronic colitis in mice by inhibiting PERK-ATF4-CHOP pathway of ER stress and NF-κB signaling.

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-1ß, 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.

Limonin ameliorates acetaminophen-induced hepatotoxicity by activating Nrf2 antioxidative pathway and inhibiting NF-κB inflammatory response via upregulating Sirt1.

BACKGROUND: Limonin, a bioactive compound from citrus plants, exerts antioxidant activities, however its therapeutic potential in acetaminophen (APAP)-induced hepatotoxicity remains unclear. PURPOSE: Our study aims to investigate the protective effect of limonin on APAP-induced hepatotoxicity and illuminate the underlying mechanisms. STUDY: 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). METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Glaucocalyxin A reverses EMT and TGF-ß1-induced EMT by inhibiting TGF-ß1/Smad2/3 signaling pathway in osteosarcoma.

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-ß1 (TGF-ß1)-induced migration, invasion and EMT of low-metastatic osteosarcoma U2OS cells. Glaucocalyxin A inhibited TGF-ß-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-ß1-induced EMT by inhibiting TGF-ß1/Smad2/3 signaling pathway in osteosarcoma. Therefore, Glaucocalyxin A might be a promising candidate against the metastasis of human osteosarcoma.

The beneficial effects of the herbal medicine Di-huang-yin-zi (DHYZ) on patients with ischemic stroke: A Randomized, Placebo controlled clinical study.

OBJECTIVES: This study aimed to investigate the safety and therapeutic efficacy of herbal drug, Di Huang Yin Zi (DHYZ), in patients affected by ischemic stroke. METHODS: In this double blind, placebo-controlled study, a total of 100 patients with recent (less than 30 days) ischemic stroke were randomized to receive DHYZ or placebo for 12 weeks. Both groups also received rehabilitation therapy during the study period. As there were 13 dropouts, a total of 45 patients on DHYZ and 42 on placebo were available for analysis. The Fugl-Meyer Assessment (FMA) and Barthel index (BI) were assessed before treatment and at 4-week intervals. RESULTS: We observed that the FMA score and BI were increased, in both groups at week 4, 8 and 12 compared with the baseline. Furthermore, significantly better FMA score was observed in patients treated with DHYZ at week 8 and 12 (both P<0.05). BI was significantly higher in DHYZ group than in placebo group at weeks 12 (P<0.05). At week 12, the 95% Confidence Intervals (CI) of mean difference of FMA and BI also indicated that the differences between two groups were statistically significant. Compared to placebo, DHYZ produced significantly greater improvement in FMA grade at week 12 (44.4% versus 23.8%, χ(2)=4.09, P<0.05). CONCLUSIONS: DHYZ showed good efficacy, safety and tolerability in patients affected by ischemic stroke. We conclude that DHYZ may be a useful therapeutic option in patients with ischemic stroke.

[The construction of SCID-Hu IC mice model and application in rAd5HPV16L1-E7 vaccine].

OBJECTIVE: To construct human-SCID chimeric mice through implantation of mononuclear cells from human cord blood and study the immunoreaction of SCID-Hu IC mice immunized with rAd5HPV16L1-E7 vaccine. METHODS: (1) Experiment groups were injected with the suspension of mononuclear cells from human cord blood through a tail vein; the control ones were injected with non serum RPMI 1640 medium. Eight weeks after implantation, blood was collected and human serum IgG level in the mice were tested, and human CD45, CD3 and CD19 were determined. (2) SCID-Hu IC mice were divided into two groups: in group A the mice were immunized intraperitoneally with rAd5HPV16L1-E7 virus and in group B the mice were immunized through nasal drip with rAd5HPV16L1-E7 virus. At the end of fourth week, the serum specific IgG antibody to rAd5HPV16L1-E7 virus, IFN-gamma in culture medium of spleen lymphocyte and T-lymphocyte propagation were tested. RESULTS: (1) In the experiment groups, the number of mice positive for human IgG was 10/15, the average values of CD45, CD3 and CD19 were (9.39+/-4.21), (3.25+/-3.99) and (1.69+/-0.75), respectively. In the control ones, the human IgG, CD45, CD3 and CD19 were negative. (2) The results in the experiment groups showed that the IFN-gamma and T-lymphocyte stimulated by HPV16 protein were higher than those in the non-stimulated group (P less than 0.05). CONCLUSION: (1) The results indicated that the construction of human-SCID chimaera through the implantation of mononuclear cells from human cord blood into SCID mice was successful. They also indicated that the reconstructed SCID-Hu IC mice has the ability to produce immune response against rAd5HPV16L1-E7 recombinant virus.