Protective effects of taurine against endotoxin-induced acute liver injury after hepatic ischemia reperfusion

Anoectochilus roxburghii polysaccharide reduces D-GalN/LPS-induced acute liver injury by regulating the activation of multiple inflammasomes

BACKGROUND

Acute liver injury (ALI) is a serious syndrome with a high mortality rate due to viral infection, toxic exposure, and autoimmunity, and its severity can range from mildly elevated liver enzymes to severe liver failure. Activation of the nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome is closely associated with the development of ALI, and the search for an inhibitor targeting this pathway may be a novel therapeutic option. Anoectochilus roxburghii polysaccharide (ARP) is a biologically active ingredient extracted from Anoectochilus roxburghii with immunomodulatory, antioxidant, and anti-inflammatory bioactivities and pharmacological effects. In this study, we focused on D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced acute liver injury by ARP through inhibition of NLRP3 inflammasome.

METHODS

An inflammasome activation model was established in bone marrow-derived macrophages (BMDMs) to investigate the effects of ARP on caspase-1 cleavage, IL-1β secretion, and ASC oligomerization in inflammasomes under different agonists. We used the D-GalN/LPS-induced acute liver injury model in mice, intraperitoneally injected ARP or MCC950, and collected liver tissues, serum, and intraperitoneal lavage fluid for pathological and biochemical indexes.

RESULTS

ARP effectively inhibited the activation of the NLRP3 inflammasome and had an inhibitory effect on non-classical NLRP3, AIM2, and NLRC4 inflammasomes. It also effectively inhibited the oligomerization of apoptosis-associated speck-like protein (ASC) from a variety of inflammatory vesicles. Meanwhile, ARP has good therapeutic effects on acute liver injury induced by D-GaIN/LPS.

CONCLUSION

The inhibitory effect of ARP on a wide range of inflammasomes, as well as its excellent protection against acute liver injury, suggests that ARP may be a candidate for acute liver injury.

Total tanshinones ameliorates cGAS-STING-mediated inflammatory and autoimmune diseases by affecting STING-IRF3 binding

BACKGROUND

An important signaling pathway connecting illness and natural immunity is the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway, but aberrant activation of this pathway is associated with the development of autoimmune and inflammatory diseases. Hence, targeted inhibition of the activation of the cGAS-STING pathway is potentially valuable in the treatment of disease. The primary active component of Salvia miltiorrhiza is total tanshinone (TTN). Research has indicated that TTN possesses noteworthy anti-inflammatory properties. However, the protective mechanism of TTN against acute liver injury (ALI) and autoimmune diseases is unknown.

METHODS

A model of aberrant activation of the cGAS-STING pathway was established in various cells and treated with TTN, and the expression of cGAS-STING pathway-related proteins, type I interferon, interferon stimulated genes and inflammatory factors was assessed by western blotting, real-time qPCR. Immunofluorescence analysis of the effect of TTN on the entry of associated proteins into the nucleus following aberrant activation of the cGAS-STING pathway. The effect of TTN on STING oligomerisation was investigated using 2'-3'-cyclic GMP-AMP (2',3'-cGAMP) to induce STING oligomerisation. Western blotting was used to examine the impact of TTN on the interactions of STING, tank-binding kinase 1 (TBK1), and interferon regulatory factor 3 (IRF3) after HA or Flag-labelled plasmids were transfected into HEK-293 T cells. A dimethylxanthenone-4-acetic acid (DMXAA) -induced activation model of the cGAS-STING pathway in mice was established to study the effect of TTN on aberrant activation of the cGAS-STING pathway in vivo. On the other hand, an animal model of lipopolysaccharide/D-galactosamine (LPS/D-GaIN)-induced ALI and an autoimmune disease model induced by trex1 knockout were established to study the effects of TTN on inflammatory and autoimmune diseases mediated by the cGAS-STING pathway in vivo.

RESULTS

In several models of aberrant activation of the cGAS-STING pathway, TTN significantly inhibited the phosphorylation of STING and IRF3, thereby suppressing the expression of type I interferon, interferon-stimulated genes and inflammatory factors. Additionally, TTN prevented P65 and IRF3 from entering the nucleus after the cGAS-STING signalling pathway was abnormally activated. Subsequent research indicated that TTN was not involved in the oligomerization of STING or the integration of STING-TBK1 and TBK1-IRF3. However, TTN was found to have a substantial effect on the binding process between STING and IRF3. On the other hand, DMXAA-induced STING activation and activation of downstream signalling in vivo are inhibited by TTN. Furthermore, TTN exhibits positive treatment effects on autoimmune diseases caused by deficiency of trex1 and LPS/D-GaIN-induced ALI.

CONCLUSION

Our research indicates that TTN effectively treats ALI and autoimmune illnesses mediated by the cGAS-STING pathway by inhibiting the abnormal activation of this pathway.

Neutrophil membrane-coated taurine nanoparticles protect against hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion (I/R) injury is a multifactorial process caused by transient tissue hypoxia and the following reoxygenation, commonly occurring in liver transplantation and hepatectomy. Hepatic I/R can induce a systemic inflammatory response, liver dysfunction, or even multiple organ failure. Although we have previously reported that taurine could attenuate acute liver injury after hepatic I/R, only a tiny proportion of the systemically injected taurine could reach the targeted organ and tissues. In this present study, we prepared taurine nanoparticles (Nano-taurine) by coating taurine with neutrophil membranes and investigated the protective effects of Nano-taurine against I/R-induced injury and the underlying mechanisms. Our results showed that Nano-taurine restored liver function by declining AST and ALT levels and reducing histology damage. Nano-taurine decreased inflammatory cytokines, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, intercellular adhesion molecule (ICAM)-1, NLR pyrin domain containing 3 (NLRP3) and apoptosis-associated speck-like protein containing CARD (ASC) and oxidants including superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), catalase (CAT) and reactive oxygen species (ROS), exhibiting anti-inflammatory and antioxidant properties. The expression of solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) was increased, while prostaglandin-endoperoxide synthase 2 (Ptgs2) was decreased upon administration of Nano-taurine, suggesting that inhibiting ferroptosis may be involved in the mechanism during hepatic I/R injury. These results suggest that Nano-taurine have a targeted therapeutic effect on hepatic I/R injury by inhibiting inflammation, oxidative stress, and ferroptosis.

Cul5 mediates taurine-stimulated mTOR mRNA expression and proliferation of mouse mammary epithelial cells

Cullin5 (Cul5) protein can regulate multiple signaling pathways; however, it is still largely unknown the role and molecule mechanism of Cul5 in regulation of the mTOR signaling. In this study, we determined the effect of Cul5 on the proliferation of HC11 cells, a mouse mammary epithelial cell line, and explored the corresponding molecular mechanism. We found that Cul5 was highly expressed in mammary gland tissues in the lactation stage compared with that in puberty and involution. Using gene knockdown and activation methods, we showed that Cul5 promoted proliferation of HC11 cells, mRNA expression and protein phosphorylation of mTOR. Taurine (Tau) affected Cul5 mRNA and protein levels in a dose-dependent manner. Cul5 localized to the nucleus and knockdown of Cul5 almost totally blocked the stimulation of Tau on mTOR mRNA expression and protein phosphorylation. PI3K inhibition almost totally abolished the stimulation of Tau on Cul5 expression. In summary, our data uncover that Cul5 is a positive regulator of proliferation of HC11 cells, and mediates the stimulation of Tau on mRNA expression and subsequent protein phosphorylation of mTOR. Our data lay a new theoretical foundation for regulating mammary cell proliferation and promoting milk yield.

Taurine attenuates valproic acid-induced hepatotoxicity via modulation of RIPK1/RIPK3/MLKL-mediated necroptosis signaling in mice

Valproic acid (VPA) is known as a common drug in seizure and bipolar disorders treatment. Hepatotoxicity is the most important complication of VPA. Taurine (Tau), an amino acid, has antioxidant effects. The present research was conducted to evaluate the protective mechanisms of Tau on VPA-induced liver injury, especially focusing on the necroptosis signaling pathway. The sixty-four male NMRI mice were divided into eight groups with eight animals per each. The experiment groups pretreated with Tau (250, 500, 1000 mg/kg) and necrostatine-1 (Nec-1, 1.8 mg/kg) and then VPA (500 mg/kg) was administered for 14 consecutive days. The extent of VPA-induced hepatotoxicity was confirmed by elevated ALP (alkaline phosphatase), AST (aspartate aminotransferase), ALT (alanine aminotransferase) levels, and histological changes as steatosis, accumulation of erythrocytes, and inflammation. Additionally, VPA significantly induced oxidative stress in the hepatic tissue by increasing ROS (reactive oxygen species) production and lipid peroxidation level along with decreasing GSH (glutathione). Hepatic TNF-α (tumor necrosis factor) level, mRNA and protein expression of RIPK1 (receptor-interacting protein kinase 1), RIPK3, and MLKL (mixed lineage kinase domain-like pseudokinase) were upregulated. Also, the phosphorylation of MLKL and RIPK3 increased in the VPA group. Tau could effectively reverse these events. Our data suggest which necroptosis has a key role in the toxicity of VPA through TNF-α-mediated RIPK1/RIPK3/MLKL signaling and oxidative stress. Our findings suggest that Tau protects the liver tissue against VPA toxicity via inhibiting necroptosis signaling pathway mediated by RIPK1/RIPK3/MLKL and suppressing oxidative stress, and apoptosis.

Bromamine T, a stable active bromine compound, prevents the LPS‑induced inflammatory response

Inflammation is the most common cause of most acute and chronic debilitating diseases. Towards unveiling novel therapeutic options for patients with such complications, N‑bromotaurine (TauNHBr) has emerged as a potential anti‑inflammatory agent; however, its therapeutic efficacy is hindered due to its relatively poor stability. To address this challenge, the present study focused on examining the effects of a stable active bromine compound, named bromamine T (BAT). The present study examined the protective properties of BAT against lipopolysaccharide (LPS)‑mediated inflammation in vitro, by using LPS‑stimulated murine J774.A1 macrophages (Mφs), as well as in vivo, by using a murine LPS‑mediated air‑pouch model. Additionally, its efficacy was compared with that of taurine, a known potent anti‑inflammatory molecule. In LPS‑stimulated J774A.1 Mφs, BAT and taurine were very effective in reducing the secretion of pro‑inflammatory mediators. The in vitro experiments indicated that LPS‑mediated inflammation was attenuated due to the protective properties of BAT and of taurine, probably through the inhibition of phosphorylated p65 NF‑κB subunit (Ser 536) nuclear translocation. The in vivo experiments also revealed that BAT and taurine inhibited LPS‑mediated inflammation by reducing total cell/polymorphonuclear cell (PMN) infiltration in the air‑pouch and by decreasing pouch wall thickness. The analysis of exudates obtained from pouches highlighted that the inhibitory effects of BAT and taurine on the secretion of pro‑inflammatory cytokines were similar to those observed in vitro. Notably, the effect of BAT at the highest concentration tested was superior to that of taurine at the highest concentration. Taken together, the findings of the present study indicate that BAT prevents the LPS‑induced inflammatory response both in vitro and in vivo.

Role of taurine, its haloamines and its lncRNA TUG1 in both inflammation and cancer progression. On the road to therapeutics? (Review)

For one century, taurine is considered as an end product of sulfur metabolism. In this review, we discuss the beneficial effect of taurine, its haloamines and taurine upregulated gene 1 (TUG1) long non‑coding RNA (lncRNA) in both cancer and inflammation. We outline how taurine or its haloamines (N‑Bromotaurine or N‑Chlorotaurine) can induce robust and efficient responses against inflammatory diseases, providing insight into their molecular mechanisms. We also provide information about the use of taurine as a therapeutic approach to cancer. Taurine can be combined with other chemotherapeutic drugs, not only mediating durable responses in various malignancies, but also circumventing the limitations met from chemotherapeutic drugs, thus improving the therapeutic outcome. Interestingly, the lncRNA TUG1 is regarded as a promising therapeutic approach, which can overcome acquired resistance of cancer cells to selected strategies. In this regard, we can translate basic knowledge about taurine and its TUG1 lncRNA into potential therapeutic options directed against specific oncogenic signaling targets, thereby bridging the gap between bench and bedside.

Chlorin e6-loaded sonosensitive magnetic nanoliposomes conjugated with the magnetic field for enhancing anti-tumor effect of sonodynamic therapy

In sonodynamic therapy (SDT), when Chlorin e6 (Ce6) accumulates in tumor tissues, its anti-tumor effect can be achieved by ultrasound activation. To increase the local drug concentration of Ce6 in tumor cells, we had established a novel drug delivery system, Ce6-loaded sonosensitive magnetic nanoliposome (Ce6/SML), which realized the targeting delivery by the external magnetic field. It was worth mentioning that the targeting release of Ce6/SML and the activation on Ce6 could be achieved simultaneously by ultrasound of SDT. In our study, after Ce6 was loaded into the sonosensitive magnetic nanoliposome (SML), the values of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in vitro and in vivo were determined, indicating the activation on Ce6 of ultrasound. The delivery system also displayed the tumor-targeting ability and anti-tumor activity, which associated with the determined tumor growth and expression levels of angiogenin (ANG), vascular endothelial growth factor (VEGF) and tumor necrosis factor-alpha (TNF-α). In conclusion, the Ce6/SML-SDT-Targeted delivery system could effectively enhance the anti-tumor activity of SDT and had a great potential application for the treatment of malignant tumors located in deep tissues.

Integrative transcriptomics and metabolomics analyses provide hepatotoxicity mechanisms of asarum

Asarum is frequently applied in combination with other agents for prescriptions in practices of Traditional Chinese Medicine. A number of studies have previously indicated that asarum treatment induces lung toxicity by triggering inflammation. However, the potential effects of asarum in the liver and the underlying mechanisms have remained largely elusive. Therefore, transcriptomics and metabolomics approaches were used in the present study to examine the mechanisms of the hepatotoxicity of asarum. Specifically, mRNA and metabolites were obtained from rat liver samples following intragastric administration of asarum powder. RNA sequencing analysis was subsequently performed to screen for differentially expressed genes (DEGs), and a total of 434 DEGs were identified in liver tissue samples, 214 of which were upregulated and 220 were downregulated. Pathway enrichment analysis found that these genes were particularly enriched in processes including the regulation of p53 signaling, metabolic pathways and bile secretion. To investigate potential changes to the metabolic profile as a result of asarum treatment, a metabolomics analysis was performed, which detected 14 significantly altered metabolites in rat liver samples by gas chromatography-mass spectrometry. These metabolites were predominantly members of the taurine, hypotaurine and amino acid metabolic pathways. Metscape network analyses were subsequently performed to integrate the transcriptomics and metabolomics data. Integrative analyis revealed that the DEGs and metabolites were primarily associated with bile acid biosynthesis, amino acid metabolism and the p53 signaling pathway. Taken together, these results provide novel insight into the mechanism of asarum-mediated hepatotoxicity, which may potentially aid the clinical diagnosis and future therapeutic intervention of asarum poisoning.

Hepatoprotective effects of total phenylethanoid glycosides from Acanthus ilicifolius L. against carbon tetrachloride-induced hepatotoxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Acanthus ilicifolius L. has been used as a folk medicine in the treatment of acute and chronic hepatitis in China for a long time. Phenylethanoid glycosides are one of main components in A. ilicifolius L.

AIM OF THE STUDY

The aim of present study was to assess the hepatoprotective activities of total phenylethanoid glycosides from A. ilicifolius L. (APhGs) against carbon tetrachloride (CCl₄)-induced liver injury in vivo and in vitro.

MATERIALS AND METHOD

The APhGs was separated by resin column chromatography. The purity of total phenylethanoid glycosides was determined by UV-Vis spectrophotometry using acteoside as a standard. The hepatoprotective activities of APhGs against CCl₄-induced liver injury were performed on experimental mice and L-02 hepatocytes. Moreover, the antioxidant activities of APhGs were tested in vitro.

RESULTS

The results showed that pre-administration of APhGs to mice decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels in serum, and improved superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) level in serum and liver tissue induced by CCl₄. Specifically, the SOD activities of APhGs-H and APhGs-M treatment groups were stronger than that of silymarin treatment group. The protective activities of APhGs were confirmed by histopathological results. Moreover, immunohistochemical analysis showed that APhGs could remarkably down-regulate the protein expression of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). In vitro experiment, APhGs was observed to increase L-02 hepatocyte viability against CCl₄-induced hepatotoxicity. In addition, antioxidation assays revealed that APhGs showed 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and ferric reducing ability.

CONCLUSION

Overall, total phenylethanoid glycosides from A. ilicifolius L. displayed promising hepatoprotective effects. These results offer a support for the medicine uses of A. ilicifolius L.

Telluric acid ameliorates hepatic ischemia reperfusion-induced injury in rats: Involvement of TLR4, Nrf2, and PI3K/Akt signaling pathways

In past tellurium-based compounds had limited use, however, their therapeutic potential have been target of interest recently due to antioxidant and anti-inflammatory capabilities in experimental endotoxemia. Nevertheless, their potential hepatoprotective effect against ischemia reperfusion (IR) injury is still obscure. This study examined the possible hepatoprotective effect of telluric acid (TELL), one of tellurium-based compound, against the deteriorating effect hepatic IR injury in rats through directing toll like receptor-4 (TLR4) cascade, phosphoinositide 3-kinase(PI3K)/Akt axis, and nuclear erythroid-related factor-2 (Nrf-2) pathway as possible mechanisms contributed to TELL's effect. Indeed, male Wistar rats were randomized into 3 groups: sham-operated, control IR and TELL (50 µg/kg). TELL was administrated once daily for seven consecutive days prior to the IR induction. Pretreatment with TELL attenuated hepatic IR injury as manifested by hampered plasma aminotransaminases and lactate dehydrogenase activities. Also, TELL opposed IR induced elevation in tissue expression/activity of high-mobility group box protein-1 (HMGB1), TLR4, myeloid differentiation primary-response protein 88 (MyD88), phospho-nuclear factor-kappa B p65 (p-NF-κB p65), phospho-mitogen activated protein kinasep38 (p-MAPKp38) and tumor necrosis factor-alpha (TNF-α). Moreover, TELL reduced the elevated thiobarbituric acid reactive substances along with increased both Nrf-2 and endothelial nitric oxide synthase (eNOS) protein expression, beside replenishment of hepatic reduced glutathione. In addition, TELL induced obvious upregulation of p-PI3K and p-Akt protein expressions together with restoration of histopathological changes in IR injury. In conclusion, TELL purveyed conceivable novel hepatoprotective mechanisms and attenuated events associated with acute hepatic injury via inhibition of TLR4 downstream axis and activation of Nrf-2 and PI3K/Akt signaling cascades. Thus, TELL may provide a novel therapeutic potential for complications of hepatic IR injury.

Enteric dysbiosis is associated with sepsis in patients

Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to microbial infection. For decades, the potential role of gut microbiota in sepsis pathogenesis has been revealed. However, the systemic and functional link between gut microbiota and sepsis has remained unexplored. To address this gap in knowledge, we carried out systematic analyses on clinical stool samples from patients with sepsis, including 16S rDNA sequencing, metabolomics, and metaproteomics analyses. In addition, we performed fecal microbiota transplantation from human to mice to validate the roles of gut microbiota on sepsis progression. We found that the composition of gut microbiota was significantly disrupted in patients with sepsis compared with healthy individuals. Besides, the microbial functions were significantly altered in septic feces as identified by metabolomics and metaproteomics analyses. Interestingly, mice that received septic feces exhibited more severe hepatic inflammation and injury than mice that received healthy feces after cecal ligation and puncture. Finally, several strains of intestinal microbiota and microbial metabolites were corelated with serum total bilirubin levels in patients with sepsis. Taken together, our data indicated that sepsis development is associated with the disruption of gut microbiota at both compositional and functional levels, and such enteric dysbiosis could promote organ inflammation and injury during sepsis.-Liu, Z., Li, N., Fang, H., Chen, X., Guo, Y., Gong, S., Niu, M., Zhou, H., Jiang, Y., Chang, P., Chen, P. Enteric dysbiosis is associated with sepsis in patients.

Hepatoprotective effects of a traditional Chinese medicine formula against carbon tetrachloride-induced hepatotoxicity in vivo and in vitro

Le-Cao-Shi (LCS), a formula of Traditional Chinese Medicine (TCM), has been used as a folk medicine for protection and treatment of liver injury. However, scientific evidences on its hepatoprotective effects have not been investigated. In this study, hepatoprotective activities of LCS water extracts (LCS-W) and ethanol extracts (LCS-E) against carbon tetrachloride (CCl₄)-induced liver damage were investigated in vivo and in vitro. In vivo experiments, pretreatment of LCS-W and LCS-E to rats significantly declined the levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and markedly increased the activity of superoxide dismutase (SOD) and ameliorated the level of malondialdehyde (MDA) induced by CCl₄ treatment. Especially, LCS-WM group significantly prevented the elevation of lipid peroxidation level induced by CCl_4, with the MDA level closed to that of normal group. Histopathological examinations further confirmed that LCS-W and LCS-E could protect the liver cells from CCl₄-induced damage. In addition, immunohistochemically analysis revealed that LCS-W could significantly down-regulated the hepatic protein expression of necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Correspondingly, LCS-W and LCS-E were observed to promote cell viability and decline the levels of ALT, AST, and lactate dehydrogenase (LDH) in vitro. It could be concluded that LCS can exert a protective effect against CCl₄-induced hepatotoxicity, which might be a potential therapeutic prescription for preventing or treating liver injury. Notably, LCS-W displayed better hepatoprotective activity against CCl₄-induced injury than that of LCS-E, suggesting that LCS extracted by water decoction has good development prospects. Our results contribute towards the validation of the traditional use of LCS in the treatment of liver disorders.

Protective Effects of Xylose-Taurine Reduced against Damages Caused by Oxidative Stress in Zebrafish Embryos In Vivo Model

The zebrafish (Danio rerio) is useful and convenient vertebrate models in various studies in human disease and drug discovery. In this present study, we first evaluated whether Xylose-Taurine reduced (X-T-R), a taurine derivate protects zebrafish embryos against oxidative stress caused by AAPH (2,2'-Azobis(2-amidinopropane) dihydrochloride). First of all, we selected the concentration of X-T-R showing no toxicity in zebrafish embryos. We identified that X-T-R significantly increased the survival of zebrafish embryo reduced by treatment of AAPH. Also, X-T-R effectively inhibited the productions of reactive oxygen species (ROS) and nitric oxide (NO) as well as the formation of cell death in zebrafish embryos. Moreover, X-T-R down-regulated the expression levels of Bax, caspase-3, caspase-9 and p53 known as pro-apoptotic molecules, whereas up-regulated those of Bcl-2, an anti-apoptotic molecule in AAPH-treated zebrafish embryos. From these results, this study reveals that X-T-R, a taurine derivate might be a potential protector against various damages caused by oxidative stress.

Taurine Attenuates Doxorubicin-Induced Toxicity on B16F10 Cells

This study aimed to investigate the effect of doxorubicin co-treatment with taurine on B16F10 melanoma cells. Frequently, Doxorubicin is used in the treatments of many different kinds of cancers, some of which are soft tissue sarcomas, hematological malignancies and carcinomas. However, the clinical application of doxorubicin is compromised by its severe adverse effects, including cardiotoxicity. In the present study, the efficacy of doxorubicin co-treatment with taurine was investigated. B16F10 cell viability was evaluated using MTT assays, trypan blue dye exclusion assays, and fluorescent staining technique. Apoptotic cells were detected by flow cytometry and the proteins associated with apoptosis and cellular differentiations were assessed by immunoblotting. Doxorubicin inhibited cell growth and induced cell death in B16F10 cells. Interestingly, doxorubicin co-treatment with taurine inhibited apoptosis in B16F10 cells. These results indicate that doxorubicin co-treatment with taurine attenuates doxorubicin-induced cytotoxicity and reduces ROS production in B16F10 cells.

Anti-inflammatory Effects of Galactose-Taurine Sodium Salt in LPS-Activated RAW 264.7 Cells

In this study, we synthesized Galactose-Taurine sodium salt (G-T) as a functional food ingredient to enhance biological activities of taurine. Also, anti-inflammatory effects of G-T were investigated in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. G-T found to reduce the generations of the LPS-stimulated nitric oxide (NO) and prostaglandin E2 (PGE2) via down-regulating the expression levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). Also, G-T reduced the secretion of inflammatory cytokines including interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF-α) in LPS-treated RAW 264.7 cells. Finally, we identified that G-T inhibits the activation of nuclear factor-κB (NF-κB) and the phosphorylation of inhibitor κB (IκB)-α. From these results, this study first suggests that G-T could be considered as an effective anti-inflammatory agent.

Effects of acute ammonia toxicity on oxidative stress, immune response and apoptosis of juvenile yellow catfish Pelteobagrus fulvidraco and the mitigation of exogenous taurine

Ammonia can easily form in intensive culture systems due to ammonification of uneaten food and animal excretion, which usually brings detrimental health effects to fish. However, little information is available on the mechanisms of the detrimental effects of ammonia stress and mitigate means in fish. In this study, the four experimental groups were carried out to test the response of yellow catfish to ammonia toxicity and their mitigation through taurine: group 1 was injected with NaCl, group 2 was injected with ammonium acetate, group 3 was injected with ammonium acetate and taurine, and group 4 was injected taurine. The results showed that ammonia poisoning could induce ammonia, glutamine, glutamate and malondialdehyde accumulation, and subsequently lead to blood deterioration (red blood cell, hemoglobin and serum biochemical index reduced), oxidative stress (superoxide dismutase and catalase activities declined) and immunosuppression (lysozyme, 50% hemolytic complement, total immunoglobulin, phagocytic index and respiratory burst reduced), but the exogenous taurine could mitigate the adverse effect of ammonia poisoning. In addition, ammonia poisoning could induce up-regulation of antioxidant enzymes (Cu/Zn-SOD, CAT, GPx and GR), inflammatory cytokines (TNF, IL-1 and IL-8) and apoptosis (p53, Bax, caspase 3 and caspase 9) genes transcription, suggesting that cell apoptotic and inflammation may relate to oxidative stress. This result will be helpful to understand the mechanism of aquatic toxicology induced by ammonia in fish.

DHA attenuates hepatic ischemia reperfusion injury by inhibiting pyroptosis and activating PI3K/Akt pathway

Hepatic ischemia reperfusion (I/R) injury is very common in liver transplantation and major liver surgeries and may cause liver failure or even death. Docosahexaenoic acid (DHA) has displayed activities in reducing oxidative stress and inflammatory reaction in many disorders. In the present study, we investigated the protective effects of DHA against I/R-induced injury and the underlying mechanisms. Here, we show that DHA protected hepatic I/R injury by reducing aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and decreasing the oxidative stress in liver tissues. The viability of Buffalo rat liver (BRL) cells was reduced by hypoxia/restoration (H/R) but restored by DHA. DHA significantly downregulated the expression of pyroptosis-related proteins including NLR pyrin domain containing 3 (NLRP3), apoptotic speck-like protein containing CARD (ASC) and cleaved caspase-1 and reduced the secretion of pro-inflammatory cytokines. The above results were supported by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. However, incubation with LY294002, a specific inhibitor of phosphatidylinositol-3-kinase (PI3K), abolished the effects of DHA, since it increased the expression of cleaved caspase-1 and the production of inflammatory cytokines. The present results have demonstrated that DHA ameliorated I/R-induced injury by inhibiting pyroptosis of hepatocytes induced in liver I/R injury in vivo and in vitro through the PI3K/Akt pathway, providing a potential therapeutic option to prevent liver injury by I/R.

Taurine supplementation reduces neuroinflammation and protects against white matter injury after intracerebral hemorrhage in rats

Intracerebral hemorrhage (ICH) initiates a neuroinflammatory cascade that contributes to substantial neuronal damage and neurological deterioration. Taurine, an abundant amino acid in the nervous system, is reported to reduce inflammatory injury in various central nervous system diseases, but its role and the possible underlying mechanisms in the pathology following ICH remains unclear. This study was designed to evaluate the effect of taurine supplementation on neurological deficits, acute inflammatory responses and white matter injury in a model of ICH in rats. Adult male Sprague-Dawley (SD) rats subjected to collagenase-induced ICH injury were injected intravenously with different concentrations of taurine or vehicle 10 min after ICH and subsequently daily for 3 days. Behavioral studies, brain water content, and assessments of hemorrhagic lesion volume were quantified at day 1 and day 3 post-ICH. Neuronal damage, peri-hematomal inflammatory responses, and white matter injury were determined at 24 h, meanwhile, the content of hydrogen sulfide (H₂S) along with the expression of cystathionine-β-synthase (CBS) and P2X7 receptor (P2X7R) in peri-hematomal tissues was analyzed to investigate the possible anti-inflammatory mechanism of taurine. Treatment with a high dosage of taurine (50 mg/kg) significantly attenuated functional deficits and reduced brain edema and hemorrhagic lesion volume after ICH. Taurine administration also resulted in significant amelioration of neuronal damage and white matter injury. These changes were associated with marked reductions in neutrophil infiltration, glial activation, and expression levels of inflammatory mediators. Moreover, the anti-inflammatory effect of taurine was accompanied by increased H₂S content, enhanced CBS expression, and less expression of P2X7R. Our study demonstrated that the high dosage of taurine supplementation effectively mitigated the severity of pathological inflammation and white matter injury after ICH, and the mechanism may be related to upregulation of H₂S content and reduced P2X7R expression.

CQMUH-011, a novel adamantane sulfonamide compound, inhibits lipopolysaccharide- and D-galactosamine-induced fulminant hepatic failure in mice

CQMUH-011, a novel adamantane sulfonamide compound, was shown to suppress macrophage activation and proliferation in our previous study. However, it is unknown whether CQMUH-011 has anti-inflammatory and hepatoprotective properties. In this study, we investigated the potential effects and mechanisms of CQMUH-011 on lipopolysaccharide (LPS)-induced RAW264.7 cell activation in vitro and LPS- and D-galactosamine (D-GalN)-induced fulminant hepatic failure (FHF) in vivo. The results showed that in RAW264.7 cells challenged by LPS, CQMUH-011 inhibited cell proliferation and induced cell cycle arrest and apoptosis. Furthermore, CQMUH-011 reduced tumor necrosis factor (TNF)-α and interleukin (IL)-1β production and down-regulated the overexpression of toll-like receptor 4 (TLR4) and nuclear factor (NF)-κB induced by LPS in RAW264.7 cells. In vivo, CQMUH-011 reduced serum levels of aspartic aminotransferase and alanine transaminase and improved the mortality and hepatic pathological damage induced by LPS/D-GalN in mice. Moreover, CQMUH-011 significantly inhibited the serum levels of proinflammatory mediators, including TNF-α, IL-6, IL-1β, nitric oxide (NO), and prostaglandin E2 (PGE₂), and down-regulated the protein expression of TLR4, p38 mitogen-activated protein kinases, NF-κB, NF-κB inhibitor α (IκBα), IκB kinase β (IKKβ), cyclooxygenase-2 (COX-2) and inducible NO synthases (iNOS) induced by LPS/D-GalN in mice. In conclusion, these results demonstrated that CQMUH-011 has a notable anti-inflammatory effect and protects mice from LPS/D-GalN-induced FHF and that the molecular mechanisms might be related to the inhibition of the TLR4/NF-κB signaling pathway activation, the subsequent decrease in proinflammatory mediator production, and the inhibition of macrophage activation.

Anti-inflammatory Effects of Galactose-Taurine Sodium Salt: A Taurine Derivate in Zebrafish In Vivo Model

Taurine, the plentiful amino acids in mammalian cells exerts various biological activities including antioxidant and anti-inflammatory effects. Inflammation can cause several diseases such as cancer, heart disease, rheumatoid arthritis and immune system reactions. Here, we investigated anti-inflammatory effects of Galactose-Taurine sodium salt (Gal-Tau), a newly synthesized taurine derivate in LPS-stimulated zebrafish embryos in vivo model. The result showed that Gal-Tau improved the survival rate and the edema in LPS-treated zebrafish embryos. Also, Gal-Tau effectively reduced the productions of nitric oxide (NO), reactive oxygen species (ROS) and cell death induced by LPS in zebrafish embryos. In addition, Gal-Tau regulated the expression levels of inflammatory mediators such as inducible NOS (iNOS) and cycloxygenase 2 (COX-2) as well as IL-6 and TNF-α, inflammatory cytokines known as important key mediators of inflammation. Taken together, this study first indicates that Gal-Tau could be considered as an effective anti-inflammatory material with its anti-inflammatory activity.

Acute ammonia toxicity in crucian carp Carassius auratus and effects of taurine on hyperammonemia

The four experimental groups were carried out to test the response of crucian carp Carassius auratus to ammonia toxicity and taurine: group 1 was injected with NaCl, group 2 was injected with ammonium acetate, group 3 was injected with ammonium acetate and taurine, and group 4 was injected with taurine. Fish in group 2 had the highest ammonia and glutamine contents, and the lowest glutamate content in liver and brain. Serum superoxide dismutase (SOD), glutathione (GSH) activities, red cell count (RBC), white cell count (WBC), lysozyme (LYZ) activity, complement C3 content of fish in group 2 reflected the lowest, but malondialdehyde content was the highest. Importantly, serum SOD and GSH activites, RBC, WBC, and LYZ activity, C3, C4 and total immunoglobulin contents of fish in group 3 were significantly higher than those of fish in group 2. This study indicates that ammonia exerts its toxic effects by interfering with amino acid transport, inducing ROS generation, leading to malondialdehyde accumulation and immunosuppression of crucian carp. The exogenous taurine could mitigate the adverse effect of high ammonia level on fish physiological disorder.

Intraperitoneal administration of apigenin in liver ischemia/reperfusion injury protective effects

BACKGROUND/AIMS

Hepatic injury caused by ischemia/reperfusion (I/R) is a clinical problem associated with major liver surgery. Among other flavonoids, apigenin has shown a promising effect on I/R cases. In this study, we have investigated the effects of apigenin after liver I/R injury in rats.

MATERIALS AND METHODS

Forty eight rats were randomized into the following eight groups: (1) Control-sham group: rats subjected to the surgical procedure, except for liver I/R; (2) DMSO group: rats subjected to surgery, except for liver I/R given the apigenin solvent dimethyl-sulfoxide intraperitoneally; (3) C60 group; (4) C120 group; (5) C240 group: rats underwent liver ischemia for 45 min followed by reperfusion for 60 min, 120 min, and 240 min; (6) AP60 group; (7) AP120 group; (8) AP240 group: rats underwent liver ischemia for 45 min, and then given apigenin (5 mg) intraperitoneally followed by reperfusion for 60 min, 120 min, and 240 min. Reverse transcription polymerase chain reaction was performed on liver tissues to measure BCL-2/BAX expression, enzyme-linked immunosorbent assay to measure M30/M65 and ICAM-1. Immunohistochemistry was used to identify M30 biomarker in liver tissues.

STATISTICAL ANALYSIS

Quantitative variables were tested by Kolmogorov-Smirnov test, repeated measures analysis of variance/Friedman test. Gene levels were assessed by Student's t-test/Mann-Whitney U-test.

RESULTS

BCL-2 levels were significantly higher in I/R apigenin groups than in I/R control groups. BAX levels were lower in the AP240 group than in C240 group. Prolongation of reperfusion resulted in increased activation of M30. ICAM-1 levels were lower in the AP240 group than in C240 group.

CONCLUSIONS

Apigenin seems to inhibit the process of apoptosis and ameliorate the hepatic I/R injury.

The protective effects of taurine on acute ammonia toxicity in grass carp Ctenopharynodon idellus

The four experimental groups were carried out to test the response of grass carp Ctenopharyngodon idella to ammonia toxicity and taurine: group 1 was injected with NaCl, group 2 was injected with ammonium acetate, group 3 was injected with ammonium acetate and taurine, and group 4 was injected taurine. Fish in group 2 had the highest ammonia content in the liver and brain, and alanine, arginine, glutamine, glutamate and glycine contents in liver. Brain alanine and glutamate of fish in group 2 were significantly higher than those of fish in group 1. Malondialdehyde content of fish in group 2 was the highest, but superoxide dismutase and glutathione activities were the lowest. Although fish in group 2 had the lowest red cell count and hemoglobin, the highest alkaline phosphatase, complement C3, C4 and total immunoglobulin contents appeared in this group. In addition, superoxide dismutase and glutathione activities, red cell count and hemoglobin of fish in group 3 were significantly higher than those of fish in group 2, but malondialdehyde content is the opposite. This study indicates that ammonia exerts its toxic effects by interfering with amino acid transport, inducing reactive oxygen species generation and malondialdehyde accumulation, leading to blood deterioration and over-activation of immune response. The exogenous taurine could mitigate the adverse effect of high ammonia level on fish physiological disorder.

Interleukin 18--binding protein ameliorates liver ischemia--reperfusion injury

BACKGROUND

The aim of this study was to investigate the possible protective effect of interleukin 18-binding protein (IL-18BP) on ischemia-reperfusion (I/R)-induced liver injury in experimental rat models. Liver is one of the most affected organs from I/R process. IL-18 is an important proinflammatory cytokine, which may induce some events such as production of reactive oxygen substances and release of various cytokines. IL-18BP acts as an inhibitor of IL-18. The relationship between IL-18 and IL-18BP has an important place in inflammatory process.

MATERIALS AND METHODS

Rats were equally divided into three groups as follows: sham: Hepatic pedicle dissection was done, but hepatic pedicle clamping was not used. I/R: Sixty minutes of ischemia and 2 h of reperfusion were applied. IR + IL-18BP: Recombinant human IL-18BP (100 μg/kg) was administered 30 min before the surgery. Hepatic pedicle was clamped during 60 min of ischemia and 2 h of reperfusion was achieved.

RESULTS

Liver enzyme levels were significantly lower in the IR + IL-18BP group, when compared with the I/R group. Serum and tissue levels of tumor necrosis factor-α, IL-6, and IL-18 were considerably lower in the IR + IL-18BP group, when compared with the I/R group, but hepatic interferon-γ and IL1β levels were not significant. Serum oxidative stress index level was significantly higher in the I/R group, when compared with the IR + IL-18BP group. In immunostaining, it was observed that pathologic changes were lower in IR + IL-18BP group than the I/R group.

CONCLUSIONS

IL-18BP exhibited anti-inflammatory, antioxidant, and protective effects in I/R-mediated hepatic injury via regulating some liver enzyme activities and cytokine levels. Additionally, these effects have been verified by histomorphologic examination and oxidative stress markers.

The protective effect of huperzine A against hepatic ischemia reperfusion injury in mice

BACKGROUND

Nowadays, hepatic ischemia reperfusion (HI/R) injury is regarded as a serious concern in clinical practices. Huperzine A (HupA) is an alkaloid isolated from the Chinese folk medicine huperzia serrate, which has possessed diverse pharmacological actions.

METHODS

A mouse model of HI/R was caused by clamping the hepatic artery, the hepatoportal vein, and the bile duct with a vascular clamp for 30 minutes followed by reperfusion for 6 hours under anesthesia. The sham group experienced the identical procedure without hepatic ischemia. The HupA group received an injection into the tail vein 5 minutes prior to HI/R at the doses of 167 and 500 μg/kg. The vehicle group was injected with physiological saline instead of HupA. The liver function was assessed by determinations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Tissue levels of superoxide dismutase (SOD), catalase (CAT), malondiadehyde (MDA), and glutathione (GSH) were also measured spectrophotometrically. In addition, the activities of hepatic inflammatory mediators such as nuclear factor kappa B (NF-κB) p65, tumor necrosis factors-α (TNF-α, interleukin-1β (IL-1β) and IL-6 were also measured. Furthermore, the apoptotic damage was evaluated by measuring caspase-3 activity in hepatic tissues.

RESULTS

Treatment with HupA in mice at the doses of 167 and 500 μg/kg remarkably reduced serum ALT and AST activities in HupA-treated ischemic mice. Furthermore, HupA treatment could enhance the activities of hepatic tissue SOD, CAT, and GSH but decrease MDA tissue content. The activities of inflammatory cytokines including NF-κB p65, TNF-α, IL-1β and IL-6 were all decreased in ischemic mice treated with HupA. Colorimetric test results illustrated that a marked reduction of caspase-3 activity was found in the HupA-treated group compared with the vehicle group.

CONCLUSION

Our present data suggest that HupA has a protective role against HI/R injury of mice and antioxidative, anti-inflammatory, and antiapoptotic actions are involved in its protection.

Butyrate protects rat liver against total hepatic ischemia reperfusion injury with bowel congestion

Hepatic ischemia/reperfusion (I/R) injury is an unavoidable consequence of major liver surgery, especially in liver transplantation with bowel congestion, during which endotoxemia is often evident. The inflammatory response aggravated by endotoxin after I/R contributes to liver dysfunction and failure. The purpose of the present study was to investigate the protective effect of butyrate, a naturally occurring four-carbon fatty acid in the body and a dietary component of foods such as cheese and butter, on hepatic injury complicated by enterogenous endotoxin, as well as to examine the underlying mechanisms involved. SD rats were subjected to a total hepatic ischemia for 30 min after pretreatment with either vehicle or butyrate, followed by 6 h and 24 h of reperfusion. Butyrate preconditioning markedly improved hepatic function and histology, as indicated by reduced transaminase levels and ameliorated tissue pathological changes. The inflammatory factors levels, macrophages activation, TLR4 expression, and neutrophil infiltration in live were attenuated by butyrate. Butyrate also maintained the intestinal barrier structures, reversed the aberrant expression of ZO-1, and decreased the endotoxin translocation. We conclude that butyrate inhibition of endotoxin translocation, macrophages activation, inflammatory factors production, and neutrophil infiltration is involved in the alleviation of total hepatic I/R liver injury in rats. This suggests that butyrate should potentially be utilized in liver transplantation.

Dietary inclusion level and time effects of taurine on broiler performance, meat quality, oxidative status and muscle taurine content

Two experiments were conducted to investigate the effect of taurine on growth performance, meat quality, oxidative status and muscle taurine content in broilers. In Experiment 1, 50 one-day-old male Cobb chicks were given a diet supplemented with 0, 0.125, 0.50, 2.00 or 8.00 g/kg taurine from 1 to 42 d of age. In Experiment 2, 80 22-d-old male Cobb chicks were given a diet supplemented with 4.00 g/kg taurine for 0, 1, 2 or 3 weeks. Taurine contents of thigh and breast muscle increased linearly with increasing dietary taurine. Taurine supplementation for 1, 2 and 3 weeks significantly increased the taurine content of breast muscle. The taurine contents of liver and thigh meat were significantly increased by taurine supplementation for 3 weeks. The taurine contents of thigh and breast meat from broilers given a diet supplemented with 4 g/kg taurine for 3 weeks increased to 1.89 times the concentrations of the control group. There were no detrimental effects on growth performance, breast or thigh muscle yield, pH value or drip-water loss, and taurine supplementation did not affect the serum carbonyl content. Serum malondialdehyde concentration was significantly decreased by taurine supplementation for 1, 2 or 3 weeks.

Carvacrol alleviates ischemia reperfusion injury by regulating the PI3K-Akt pathway in rats

Background

Liver ischemia reperfusion (I/R) injury is a common pathophysiological process in many clinical settings. Carvacrol, a food additive commonly used in essential oils, has displayed antimicrobials, antitumor and antidepressant-like activities. In the present study, we investigated the protective effects of carvacrol on I/R injury in the Wistar rat livers and an in vitro hypoxia/restoration (H/R) model.

Methods

The hepatoportal vein, hepatic arterial and hepatic duct of Wistar rats were isolated and clamped for 30 min, followed by a 2 h reperfusion. Buffalo rat liver (BRL) cells were incubated under hypoxia for 4 h, followed normoxic conditions for 10 h to establish the H/R model in vitro. Liver injury was evaluated by measuring serum levels of alanine aminotransferase (ALT) and aspatate aminotransferase (AST), and hepatic levels of superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and malondiadehyde (MDA), and hepatic histology and TUNEL staining. MTT assay, flow cytometric analysis and Hoechst 33258 staining were used to evaluate the proliferation and apoptosis of BRL cells in vitro. Protein expression was examined by Western Blot analysis.

Results

Carvacrol protected against I/R-induced liver damage, evidenced by significantly reducing the serum levels of ALT and AST, histological alterations and apoptosis of liver cells in I/R rats. Carvacrol exhibited anti-oxidative activity in the I/R rats, reflected by significantly reducing the activity of SOD and the content of MDA, and restoring the activity of CAT and the content of GSH, in I/R rats. In the in vitro assays, carvacrol restored the viability and inhibited the apoptosis of BRL cells, which were subjected to a mimic I/R injury induced by hypoxia. In the investigation on molecular mechanisms, carvacrol downregulated the expression of Bax and upregulated the expression of Bcl-2, thus inhibited the activation of caspase-3. Carvacrol was also shown to enhance the phosphorylation of Akt.

Conclusion

The results suggest that carvacrol could alleviate I/R-induced liver injury by its anti-oxidative and anti-apoptotic activities, and warrant a further investigation for using carvacrol to protect I/R injury in clinic.

Huperzine A attenuates hepatic ischemia reperfusion injury via anti-oxidative and anti-apoptotic pathways

Hepatic ischemia reperfusion (HI/R) injury may occur during liver transplantation and remains a serious concern in clinical practice. Huperzine A (HupA), an alkaloid isolated from the Chinese traditional medicine Huperzia serrata, has been demonstrated to possess anti‑oxidative and anti‑apoptotic properties. In the present study, a rat model of HI/R was established by clamping the hepatic artery, the hepatoportal vein and the bile duct with a vascular clamp for 30 min followed by reperfusion for 6 h under anesthesia. HupA was injected into the tail vein 5 min prior to the induction of HI/R at doses of 167 and 500 µg/kg. The histopathological assessment of the liver was performed using hematoxylin and eosin staining. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were assayed in the serum samples. The tissue levels of superoxide dismutase (SOD), catalase (CAT), malondiadehyde (MDA) and glutathione (GSH) were also measured spectrophotometrically. Furthermore, the protein expression of caspase‑3, Bcl‑2 and Bax in hepatic tissues was detected via western blot analysis. Treatment of Wistar rats with HupA at doses of 167 and 500 µg/kg markedly attenuated HI/R injury as observed histologically. In addition, the significant reductions of serum ALT and AST were observed in HupA‑treated ischemic rats. Furthermore, HupA treatment enhanced the activity of hepatic tissue SOD, CAT and GSH, but decreased the MDA tissue content. Western blot analysis revealed elevated levels of Bcl‑2 expression but decreased Bax and caspase‑3 tissue expression at the protein level in the HupA‑treated group. The present data suggest that HupA attenuates the HI/R injury of rats through its anti‑oxidative and anti‑apoptotic signaling pathways.

A novel in situ model of liver cold ischemia-reperfusion in rats

BACKGROUND

Orthotopic liver transplantation (OLT) is being used for studying cold ischemia reperfusion (I/R)-induced injury in experimental animals, but the technique is complicated and it does not accurately reflect the pathophysiology. Here, we report a novel model, termed "in situ liver cold ischemia (ISLCI)", in Wistar rats.

METHODS

ISLCI was achieved in rats by establishing a portal-jugular shunt and a cannula shunt in inferior vena cava, and the liver was continuously perfused with lactate Ringer's solution at a speed of 150 mL/h through the portal vein for 60 min. Portal venous pressure, serum levels of total bilirubin, alkaline phosphatase, alanine aminotransferase and γ-glutamyl transpeptidase (GGT), and hepatic histopathology were examined, and compared with rats undergoing OLT, in which the donor liver was subjected to a 60 min cold ischemia.

RESULTS

Livers from ISLCI and OLT rats showed histopathologic changes characteristic of I/R-induced injury when examined on days 1 and 7, with complete recovery 14 d after reperfusion. Compared with OLT rats, ISLCI rats had significantly lower levels of portal venous pressure 1 and 10 min after porta hepatis clamping. They suffered a milder degree of I/R-induced hepatic injury, reflected by significantly lower levels of GGT, alanine aminotransferase, and alkaline phosphatase on day 1, and a significant lower level of GGT and a lower histopathologic score on day 7 after reperfusion.

CONCLUSIONS

Our preliminary results indicate that the ISLCI model is reliable and technically easier, and is superior to OLT for studying cold I/R injury.

Saturated hydrogen saline attenuates endotoxin-induced acute liver dysfunction in rats

To determine the effect of saturated hydrogen saline on lipopolysaccharide (LPS)-induced acute liver dysfunction, rats were divided into control, LPS, and LPS plus saturated hydrogen saline (LPS+H(2)) groups. Treatment with saturated hydrogen saline prolonged the median survival time and reduced liver dysfunction. Moreover, saturated hydrogen saline significantly reduced pathological alterations in liver tissues, the number of ballooned hepatocytes, serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 levels, and myeloperoxidase (MPO) and malondialdehyde (MDA) levels in liver tissues (P<0.05). Cell apoptosis was detected in liver tissues after LPS treatment, and attenuated by saturated hydrogen saline treatment. Saturated hydrogen saline also decreased phosphorylated extracellular signal-regulated kinase (p-ERK), phosphorylated Jun kinase (p-JNK), nuclear factor-kappa B (NF-kappaB), and second mitochondria-derived activator of caspase (Smac) levels, and increased p38 activation (P<0.05). Thus, saturated hydrogen saline may attenuate LPS-induced acute liver dysfunction in rats, possibly by reducing inflammation and cell apoptosis. Mitogen-activated protein kinase (MAPK), NF-kappaB, and Smac may contribute to saturated hydrogen saline-mediated liver protection.

Taurine improves functional and histological outcomes and reduces inflammation in traumatic brain injury

We investigated the effect of taurine on inflammatory cytokine expression, on astrocyte activity and cerebral edema and functional outcomes, following traumatic brain injury (TBI) in rats. 72 rats were randomly divided into sham, TBI and Taurine groups. Rats subjected to moderate lateral fluid percussion injury were injected intravenously with taurine (200mg/kg) or saline immediately after injury or daily for 7days. Functional outcome was evaluated using Modified Neurological Severity Score (mNSS). Glial fibrillary acidic protein (GFAP) of the brain was measured using immunofluorescence. Concentration of 23 cytokines and chemokines in the injured cortex at 1 and 7days after TBI was assessed by Luminex xMAP technology. The results showed that taurine significantly improved functional recovery except 1day, reduced accumulation of GFAP and water content in the penumbral region at 7days after TBI. Compared with the TBI group, taurine significantly suppressed growth-related oncogene (GRO/KC) and interleukin (IL)-1β levels while elevating the levels of regulated on activation, normal T cell expressed and secreted (RANTES) at 1day. And taurine markedly decreased the level of 17 cytokine: eotaxin, Granulocyte colony-stimulating factor (G-CSF), Granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), IL-1α, IL-1β, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, IL-17, leptin, monocyte chemotactic protein-1 (MCP-1), tumor necrosis factor-alpha (TNF-α), vascular endothelial growth factor (VEGF), and only increased the level of MIP-1α in a week. The results suggest that taurine effectively mitigates the severity of brain damage in TBI by attenuating the increase of astrocyte activity and edema as well as pro-inflammatory cytokines.

Comparison of taurine, GABA, Glu, and Asp as scavengers of malondialdehyde in vitro and in vivo

The purpose of this study is to determine if amino acid neurotransmitters such as gamma-aminobutyric acid (GABA), taurine, glutamate (Glu), and aspartate (Asp) can scavenge activated carbonyl toxicants. In vitro, direct reaction between malondialdehyde (MDA) and amino acids was researched using different analytical methods. The results indicated that scavenging activated carbonyl function of taurine and GABA is very strong and that of Glu and Asp is very weak in pathophysiological situations. The results provided perspective into the reaction mechanism of taurine and GABA as targets of activated carbonyl such as MDA in protecting nerve terminals. In vivo, we studied the effect of taurine and GABA as antioxidants by detecting MDA concentration and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. It was shown that MDA concentration was decreased significantly, and the activities of SOD and GSH-Px were increased significantly in the cerebral cortex and hippocampus of acute epileptic state rats, after the administration of taurine and GABA. The results indicated that the peripherally administered taurine and GABA can scavenge free radicals and protect the tissue against activated carbonyl in vivo and in vitro.

Taurine attenuates liver injury by downregulating phosphorylated p38 MAPK of Kupffer cells in rats with severe acute pancreatitis

This study was undertaken to clarify the effects of taurine on liver injury in rats with severe acute pancreatitis (SAP). Rats were randomly assigned to three groups: a sham operation (SO), a SAP (established by infusion of 5% taurocholate), and a SAP given taurine (Taur). At 12 and 24 h post-operation, taurine pretreatment significantly attenuated hepatic tissue injury induced by SAP, and concurrently, serum alanine aminotransferase, aspartate transaminase, and amylase levels were significantly reduced by taurine pretreatment. Compared with the SO group, the total and phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) expression and nuclear factor-κB (NF-κB) activity of Kupffer cells (KCs) were significantly higher in the SAP group, but taurine pretreatment inhibited the total and phosphorylated p38 MAPK expression and NF-κB activity of KCs in the SAP group. The increase of tumor necrosis factor-α and interleukin-lβ in cultured supernate of the SAP rat-derived KCs was also significantly inhibited by taurine pretreatment. These results suggest that taurine pretreatment ameliorated liver injury in rats with SAP mainly by inhibiting phosphorylated p38 MAPK and NF-κB activity in KCs, which may play an important role in liver injury.

Taurine attenuates lipopolysaccharide-induced disfunction in mouse mammary epithelial cells

The intent of this study was to evaluate the active defense reaction of mouse mammary epithelial cells and the cytoprotective and anti-inflammatory properties of taurine to lipopolysaccharide (LPS)-induced disfunction in mouse mammary epithelial cells. (1) Primary cultured mouse mammary epithelial cells were stimulated with LPS for 24 h (final concentration=0, 5, 10, 20 μg/mL). Western blotting demonstrated a significant decrease in the secretion of β-casein in the 20 μg/mL LPS treatment group (P<0.05), while nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), lactoferrin (LF) and N-acetyl-β-D-glucosaminidase (NAGase) were all significantly increased following LPS treatment (P<0.01). Furthermore, cell survival was significantly inhibited after treatment with 20 μg/mL LPS; however, neither 5 μg/mL nor 10 μg/mL LPS had any effect on cell survival. Therefore, a level of 10 μg/mL LPS was selected to test the protective effect of taurine on mouse mammary epithelial cells. (2) Primary cultured mouse mammary epithelial cells were treated with 0, 5, 15 or 45 mmol/L taurine for 3 h, followed by 10 μg/mL LPS for 24 h. Taurine significantly attenuated the LPS-induced increase in NAGase activity, NO concentrations and the level of TNF-α, IL-1β, IL-6 and LF. Taurine at 45 mmol/L markedly increased β-casein secretion in response to LPS-induced disfunction. This study demonstrated that the addition of taurine to a culture medium significantly inhibited the LPS-induced release of inflammatory factors and increased β-casein secretion from mammary epithelial cells, thereby providing a possible explanation for the protective effect proposed for taurine in the prevention of LPS-induced disfunction in mammary epithelial cells.

Radiation protection following nuclear power accidents: a survey of putative mechanisms involved in the radioprotective actions of taurine during and after radiation exposure

There are several animal experiments showing that high doses of ionizing radiation lead to strongly enhanced leakage of taurine from damaged cells into the extracellular fluid, followed by enhanced urinary excretion. This radiation-induced taurine depletion can itself have various harmful effects (as will also be the case when taurine depletion is due to other causes, such as alcohol abuse or cancer therapy with cytotoxic drugs), but taurine supplementation has been shown to have radioprotective effects apparently going beyond what might be expected just as a consequence of correcting the harmful consequences of taurine deficiency per se. The mechanisms accounting for the radioprotective effects of taurine are, however, very incompletely understood. In this article an attempt is made to survey various mechanisms that potentially might be involved as parts of the explanation for the overall beneficial effect of high levels of taurine that has been found in experiments with animals or isolated cells exposed to high doses of ionizing radiation. It is proposed that taurine may have radioprotective effects by a combination of several mechanisms: (1) during the exposure to ionizing radiation by functioning as an antioxidant, but perhaps more because it counteracts the prooxidant catalytic effect of iron rather than functioning as an important scavenger of harmful molecules itself, (2) after the ionizing radiation exposure by helping to reduce the intensity of the post-traumatic inflammatory response, and thus reducing the extent of tissue damage that develops because of severe inflammation rather than as a direct effect of the ionizing radiation per se, (3) by functioning as a growth factor helping to enhance the growth rate of leukocytes and leukocyte progenitor cells and perhaps also of other rapidly proliferating cell types, such as enterocyte progenitor cells, which may be important for immunological recovery and perhaps also for rapid repair of various damaged tissues, especially in the intestines, and (4) by functioning as an antifibrogenic agent. A detailed discussion is given of possible mechanisms involved both in the antioxidant effects of taurine, in its anti-inflammatory effects and in its role as a growth factor for leukocytes and nerve cells, which might be closely related to its role as an osmolyte important for cellular volume regulation because of the close connection between cell volume regulation and the regulation of protein synthesis as well as cellular protein degradation. While taurine supplementation alone would be expected to exert a therapeutic effect far better than negligible in patients that have been exposed to high doses of ionizing radiation, it may on theoretical grounds be expected that much better results may be obtained by using taurine as part of a multifactorial treatment strategy, where it may interact synergistically with several other nutrients, hormones or other drugs for optimizing antioxidant protection and minimizing harmful posttraumatic inflammatory reactions, while using other nutrients to optimize DNA and tissue repair processes, and using a combination of good diet, immunostimulatory hormones and perhaps other nontoxic immunostimulants (such as beta-glucans) for optimizing the recovery of antiviral and antibacterial immune functions. Similar multifactorial treatment strategies may presumably be helpful in several other disease situations (including severe infectious diseases and severe asthma) as well as for treatment of acute intoxications or acute injuries (both mechanical ones and severe burns) where severely enhanced oxidative and/or nitrative stress and/or too much secretion of vasodilatory neuropeptides from C-fibres are important parts of the pathogenetic mechanisms that may lead to the death of the patient. Some case histories (with discussion of some of those mechanisms that may have been responsible for the observed therapeutic outcome) are given for illustration of the likely validity of these concepts and their relevance both for treatment of severe infections and non-infectious inflammatory diseases such as asthma and rheumatoid arthritis.