Diallyl sulfide protects against lipopolysaccharide/d-galactosamine-induced acute liver injury by inhibiting oxidative stress, inflammation and apoptosis in mice

Potential protective role of Lycium ruthenicum Murray polysaccharides against lipopolysaccharide-induced liver injury via mitochondrial biogenesis

Acute liver injury (ALI), which manifests as abnormal liver function and hepatocyte damage, lacks effective treatment modalities and is associated with a high mortality rate. Recent studies have revealed that hepatoprotection is related to polysaccharide components. In this study, we examined the effect and mechanism of Lycium ruthenicum Murray polysaccharides (LRMP) on liver injury induced by lipopolysaccharide (LPS). Male ICR mice were pre-administered LRMP (100 and 400 mg/kg BW) once daily for 21 days. A single injection of LPS (10 mg/kg BW) was administered on day 21 to induce ALI. The difference between the groups indicated that LRMP supplementation had no adverse effect on body weight. LRMP administration considerably alleviated liver injury, as evidenced by the decreased levels of aspartate transaminase and alanine transaminase, increased levels of albumin, and preservation of liver structural integrity. Moreover, LRMP reduced oxidative stress and inflammatory responses in the liver, maintained mitochondrial structure, regulated mitochondrial apoptotic pathway, and upregulated Sirtuin 1/peroxisome proliferator-activated receptor γ coactivator-1α signalling pathway involved in mitochondrial biogenesis. This study suggests the potential therapeutic application of LRMP in liver-related diseases, which will provide a basis for innovative strategies.

Transcranial near-infrared light promotes remyelination through AKT1/mTOR pathway to ameliorate postoperative neurocognitive disorder in aged mice

Postoperative neurocognitive disorder (PND) is a prevalent complication following surgery and anesthesia, characterized by progressive cognitive decline. The precise etiology of PND remains unknown, and effective targeted therapeutic strategies are lacking. Transcranial near-infrared light (tNIRL) has shown potential benefits for cognitive dysfunction diseases, but its effect on PND remains unclear. Our previous research indicated a close association between demyelination and PND. In other central nervous system (CNS) disorders, tNIRL has been demonstrated to facilitate remyelination in response to demyelination. In this study, we established the PND model in 18-month-old male C57BL/6 mice using isoflurane anesthesia combined with left common carotid artery exposure. Following surgery, PND-aged mice were subjected to daily 2.5-minute tNIRL treatment at 810 nm for three consecutive days. Subsequently, we observed that tNIRL significantly improved cognitive performance and reduced inflammatory cytokine levels in the hippocampus of PND mice. Furthermore, tNIRL increased the expression of oligodendrocyte transcription factor 2 (OLIG2) and myelin basic protein (MBP), promoting remyelination while enhancing synaptic function-associated proteins such as synaptophysin (SYP) and postsynaptic density protein 95 (PSD95). Further investigation revealed that tNIRL may activate the AKT1/mTOR pathway to facilitate remyelination in PND mice. These findings indicate that tNIRL is a novel non-invasive therapeutic approach for treating PND.

High molecular weight polysaccharides from Ganoderma lucidum attenuates inflammatory responses, gut microbiota, and liver metabolomic in lipopolysaccharide-induced liver injury mice

High molecular weight polysaccharides (GLPH, ≥300 kDa) are the major compounds of Ganoderma lucidum with improving liver function. However, the effect of GLPH on improving acute liver injury (ALI) wasn't revealed. Herein, the ameliorating effects and mechanisms of GLPH were revealed in lipopolysaccharide (LPS)-ALI mice. The results indicated that GLPH intervention (100 mg/kg day) reduced the serum ALT (22.67 ± 6.48 U/L), AST (21.19 ± 7.08 U/L), ALP (56.98 ± 12.71 U/L), GGT (1.48 ± 0.22 U/L) levels in ALI mice (p < 0.01). GLPH activated the hepatic antioxidant enzymes activity [SOD (3.75 ± 1.17 U/mg prot.) and CAT (3.01 ± 0.85 U/mg prot.)] and suppressed the hepatic inflammatory cytokines production [TNF-α (40.14 ± 8.15 pg/mg prot.), IL-1β (35.47 ± 10.90 pg/mg prot.), and IL-6 (8.44 ± 1.71 pg/mg prot.)] by regulating the Nrf2/OH-1 and Tlr4/NF-κB pathway (p < 0.05). Furthermore, GLPH regulated the abundance of Bifidobacterium, Akkermansia, Anaerovorax, and Tyzzerella, which associated with cecal SCFAs, hepatic inflammatory cytokines and antioxidant enzymes. GLPH significantly changed 85 liver metabolites (p < 0.01), which is beneficial for prevent the development of ALI. These results suggested GLPH displayed promising prebiotic properties in relieving ALI, regulating gut microbiota and liver metabolism.

Acetylcorynoline alleviates acute liver injury via inhibiting TLR4/JNK/NF-ĸB pathway Based on RNA-seq and molecular docking in vivo and in vitro

Acute liver injury is characterized by massive inflammatory cell infiltration, destruction of liver structure and abnormalities in liver function. Acetylcorynoline (AC) is one of the main chemical components of Corydalis bungeana Turcz. which has been shown to have a protective effect against acute liver injury. However, Whether AC is protective against acute liver injury remains unclear. This study aimed to explore the protective mechanism of AC against acute liver injury from in vivo as well as experiments in vitro. In experimental in vivo studies, AC pretreatment reduced the serum levels of ALT and AST and inhibited the expression of inflammatory factors in the liver of LPS/D-GalN-induced mice and alcohol liver disease mice. RNA-sequencing and molecular docking were used to predict that AC exerts its anti-inflammatory effects through the Toll-like receptor signaling pathway. Using RT-qPCR and Western blotting to detect expression levels of key genes and nodal proteins of the Toll-like receptor signaling pathway, AC was found to inhibit the phosphorylation of nuclear factor-kappaB (NF-ĸB) and c-Jun amino-terminal kinase (JNK). This finding was validated in cellular experiments. In conclusion, AC exerts its anti-hepatic injury effect by suppressing inflammation through inhibition of the TLR4/JNK/NF-ĸB pathway.

Modulation of the crosstalk between Keap1/Nrf2/HO-1 and NF-κB signaling pathways by Tomatidine protects against inflammation/oxidative stress-driven fulminant hepatic failure in mice

Fulminant hepatic failure (FHF) is the terminal phase of acute liver injury, which is characterized by massive hepatocyte necrosis and rapid hepatic dysfunction in patients without preexisting liver disease. There are currently no therapeutic options for such a life-threatening hepatic failure except liver transplantation; therefore, the terminal phase of the underlying acute liver injury should be avoided. Tomatidine (TOM), asteroidal alkaloid, may have different biological activities, including antioxidant and anti-inflammatory effects. Herein, the lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced FHF mouse model was established to explore the protective potential of TOM and the underlying mechanisms of action. TOM pretreatment significantly inhibited hepatocyte necrosis and decreased serum aminotransferase activities in LPS/D-GalN-stimulated mice. TOM further increased the level of different antioxidant enzymes while reducing lipid peroxidation biomarkers in the liver. These beneficial effects of TOM were shown to be associated with targeting of NF-κB signaling pathways, where TOM repressed NF-κB activation and decreased LPS/D-GalN-induced TNF-α, IL-6, IL-1β, and iNOS production. Moreover, TOM prevented LPS/D-GalN-induced upregulation of Keap1 expression and downregulation of Nrf2 and HO-1 expression, leading to increased Nrf2-binding activity and HO-1 levels. Besides, TOM pretreatment repressed LPS/D-GalN-induced upregulation of proliferating cell nuclear antigen (PCNA) expression, which spared the hepatocytes from damage and subsequent repair following the LPS/D-GalN challenge. Collectively, our findings revealed that TOM has a protective effect on LPS/D-GalN-induced FHF in mice, showing powerful antioxidant and anti-inflammatory effects, primarily mediated via modulating Keap1/Nrf2/HO-1 and NF-κB/TNF-α/IL-6/IL-1β/iNOS signaling pathways.

Synergistic effects of combined treatment of 1,2-dichloroethane and high-dose ethanol on liver damage in mice and the related mechanisms

Our previous studies have shown that the metabolism of 1,2-dichloroethane (1,2-DCE) mediated by CYP2E1 could result in oxidative damage in the liver of mice. In the current study, we further investigated the effects of combined treatment with 1,2-DCE and high dose ethanol on liver and the mechanisms since both of them can be metabolized by CYP2E1 in the liver. There are several novel findings in the current study. First, combined treatment of mice with 1,2-DCE and high-dose ethanol could synergistically upregulate both protein and mRNA levels of CYP2E1, which might aggravate liver damage through CYP2E1-mediated oxidative stress. Second, the combined treatment could also synergistically trigger NLRP3 inflammasome activation and inflammatory responses in the liver. Third, the combined treatment synergistically upregulated the antioxidant defence systems in response to oxidative stress, however the compensatory mechanisms of antioxidant defence systems appeared to be insufficient to protect liver damage in the mice. Finally, the upregulated CYP2E1 expression was confirmed by using its specific inhibitor to play the crucial roles in liver damage in the mice during the combined treatment.

Capsaicin protects against septic acute liver injury by attenuation of apoptosis and mitochondrial dysfunction

Capsaicin is the main pungent bioactive constituent in red chili with promising therapeutic properties due to its anti-oxidative and anti-inflammatory effects. No evidence exists on the beneficial effect of capsaicin on apoptosis and mitochondrial function in acute liver injury (ALI) under septic conditions. For inducing septic ALI, lipopolysaccharide (LPS, 50 μg/kg) and d-galactose (D-Gal, 400 mg/kg) was intraperitoneally injected and capsaicin was given orally at 5 or 20 mg/kg. Functional markers of liver function and mitochondrial dysfunction were determined as well as hepatic assessment of apoptotic, oxidative, and inflammatory factors. Capsaicin at the higher dose appropriately decreased serum level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in addition to reducing hepatic level of malondialdehyde (MDA), reactive oxygen species (ROS), nitrite, NF-kB, TLR4, IL-1β, TNF-α, caspase 3, DNA fragmentation and boosting sirtuin 1, Nrf2, superoxide dismutase (SOD) activity, and heme oxygenase (HO-1). These beneficial effects of capsaicin were associated with reversal and/or improvement of gene expression for pro-apoptotic Bax, anti-apoptotic Bcl2, mitochondrial and metabolic regulators PGC-1α, sirtuin 1, and AMPK, and inflammation-associated factors. Additionally, capsaicin exerted a hepatoprotective effect, as revealed by its reduction of liver histopathological changes. These findings evidently indicate hepatoprotective property of capsaicin under septic conditions that can be attributed to its down-regulation of oxidative and inflammatory processes besides its potential to attenuate mitochondrial dysfunction and apoptosis.

MALAT1-mediated EZH2 Recruitment to the GFER Promoter Region Curbs Normal Hepatocyte Proliferation in Acute Liver Injury

BACKGROUND AND AIMS

The goal of this study was to investigate the mechanism by which the long noncoding RNA MALAT1 inhibited hepatocyte proliferation in acute liver injury (ALI).

METHODS

Lipopolysaccharide (LPS) was used to induce an ALI cellular model in HL7702 cells, in which lentivirus vectors containing MALAT1/EZH2/GFER overexpression or knockdown were introduced. A series of experiments were performed to determine their roles in liver injury, oxidative stress injury, and cell biological processes. The interaction of MALAT1 with EZH2 and enrichment of EZH2 and H3K27me3 in the GFER promoter region were identified. Rats were treated with MALAT1 knockdown or GFER overexpression before LPS induction to verify the results derived from the in vitro assay.

RESULTS

MALAT1 levels were elevated and GFER levels were reduced in ALI patients and the LPS-induced cell model. MALAT1 knockdown or GFER overexpression suppressed cell apoptosis and oxidative stress injury induced cell proliferation, and reduced ALI. Functionally, MALAT1 interacted directly with EZH2 and increased the enrichment of EZH2 and H3K27me3 in the GFER promoter region to reduce GFER expression. Moreover, MALAT1/EZH2/GFER was activated the AMPK/mTOR signaling pathway.

CONCLUSION

Our study highlighted the inhibitory role of reduced MALAT1 in ALI through the modulation of EZH2-mediated GFER.

ATM deficiency aggravates the progression of liver fibrosis induced by carbon tetrachloride in mice

Ataxia telangiectasia mutated (ATM) is a pivotal sensor during the DNA damage response that slows cell passage through the cell cycle checkpoints to facilitate DNA repair, and liver fibrosis is an irreversible pathological consequence of the sustained wound-healing process, However, the effects of ATM on the development of liver fibrosis are still not fully understood. Therefore, the aim of the study was to investigate the effects and potential mechanisms of ATM on the progression of liver fibrosis. Wild-type and ATM-deficient were administered with carbon tetrachloride (CCl₄, 5 ml/kg, i.p.) for 8 weeks to induce liver fibrosis, and the liver tissues and serum were collected for analysis. KU-55933 (10 μM) was used to investigate the effects of ATM blockage on CCl₄-induced hepatocyte injury in vitro. The results showed that ATM deficiency aggravated the increased serum transaminase levels and liver MDA, HYP, and 8-OHdG contents compared with the model group (p < 0.05). Sirius red staining showed that ATM deficiency exacerbated liver collagen deposition in vivo, which was associated with the activation of TGF-β1/Smad2 signaling. Furthermore, blocking ATM with KU-55933 exacerbated the production of ROS and DNA damage caused by CCl₄ exposure in HepG2 cells, and KU-55933 treatment also reversed the downregulated expression of CDK1 and CDK2 after CCl₄ exposure in vitro. Moreover, the loss of ATM perturbed the regulation of the hepatic cell ChK2-CDC25A/C-CDK1/2 cascade and apoptosis in vivo, which was accompanied by increased Ki67-positive and TUNEL-positive cells after chronic CCl₄ treatment. In conclusion, our results indicated that ATM might be a critical regulator of liver fibrosis progression, and the underlying mechanisms of exacerbated liver fibrosis development in ATM-deficient mice might be associated with the dysregulation of hepatic cell proliferation and apoptosis.

Sulfur compounds: From plants to humans and their role in chronic disease prevention

Sulfur is essential for the health of plants and is an indispensable dietary component for human health and disease prevention. Its incorporation into our food supply is heavily reliant upon the uptake of sulfur into plant tissue and our subsequent intake. Dietary requirements for sulfur are largely calculated based upon requirements for the sulfur-containing amino acids (SAA), cysteine and methionine, to meet the demands for synthesis of proteins, enzymes, co-enzymes, vitamins, and hormones. SAA are found in abundance in animal sources and are relatively low in plants. However, some plants, particularly cruciferous and allium vegetables, produce many protective sulfur-containing secondary metabolites, such as glucosinolates and cysteine sulfoxides. The variety and quantity of these sulfur-containing metabolites are extensive and their effects on human health are wide-reaching. Many benefits appear to be related to sulfur's role in redox biochemistry, protecting against uncontrolled oxidative stress and inflammation; features consistent within cardiometabolic dysfunction and many chronic metabolic diseases of aging. This narrative explores the origins and importance of sulfur, its incorporation into our food supply and dietary sources. It also explores the overarching potential of sulfur for human health, particularly around the amelioration of oxidative stress and chronic inflammation, and subsequent chronic disease prevention.

Fibroblast growth factor 9 attenuates sepsis-induced fulminant hepatitis in mice

Sepsis-induced fulminant hepatitis (FH) is a fatal syndrome that has a worse prognosis in clinical practice. Hence, seeking effective agents for sepsis-induced FH treatment is urgently needed. Fibroblast growth factors (FGFs) are vital for tissue homeostasis and damage repair in various organs including the liver. Our study aims to investigate the protective effects and potential mechanisms of FGF9 on lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced FH in mice. We found that pre-treatment with FGF9 exhibited remarkable hepaprotective effects on liver damage caused by LPS/D-Gal, as manifested by the concomitant decrease in mortality and serum aminotransferase activities, and the attenuation of hepatocellular apoptosis and hepatic histopathological abnormalities in LPS/D-Gal-intoxicated mice. We further found that FGF9 alleviated the infiltration of neutrophils into the liver, and decreased the serum levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in LPS/D-Gal-challenged mice. These effects can be explained at least in part by the inhibition of NF-κB signaling pathway. Meanwhile, FGF9 enhanced the antioxidative defense system in mice livers by upregulating the expression of NRF-2-related antioxidative enzymes, including glutamate-cysteine ligase catalytic subunit (GCLC), NAD(P)H: quinone oxidoreductase 1 (NQO-1), and heme oxygenase-1 (HO-1). These data indicate that FGF9 represents a promising therapeutic drug for ameliorating sepsis-induced FH via its anti-apoptotic and anti-inflammatory capacities.

Hepatoprotective effect of diallyl trisulfide against lipopolysaccharide and D-galactosamine induced acute liver failure in mice via suppressing inflammation and apoptosis

Acute liver failure (ALF), characterized by the quick occurrence of disorder in liver, is a serious liver injury with extremely high mortality. Therefore, we investigated whether diallyl trisulfide (DATS), a natural product from garlic, protected against ALF in mice and studied underlying mechanisms. In the present study, lipopolysaccharide (LPS) (10 μg·kg^-1)/D-galactosamine (D-gal) (500 mg·kg^-1) was intraperitoneally injected to ICR mice to induce ALF. The mice were orally administered 20-, 40-, or 80-mg·kg^-1 DATS) 1 h before LPS/D-gal exposure. Serum biochemical analyses and pathological study found that DATS pretreatment effectively prevented the ALF in LPS/D-gal-treated mice. Mechanistically, pretreatment of DATS inhibited the increase of the numbers of CD11b⁺ Kupffer cells and other macrophages in the liver, the release of tumor necrosis factor-α into the blood, and Caspase-1 activation induced by LPS/D-gal treatment in mice. Furthermore, DATS inhibited the activation of Caspase-3, downregulation of Bcl-2/Bax ratio, and increase of TUNEL positive staining. Altogether, our findings suggest that DATS exhibits hepatoprotective effects against ALF elicited by LPS/D-gal challenge, which probably associated with anti-inflammation and anti-apoptosis.

Hydrogen Sulfide Inhibits Inflammatory Pain and Enhances the Analgesic Properties of Delta Opioid Receptors

Chronic inflammatory pain is present in many pathologies and diminishes the patient's quality of life. Moreover, most current treatments have a low efficacy and significant side effects. Recent studies demonstrate the analgesic properties of slow-releasing hydrogen sulfide (H₂S) donors in animals with osteoarthritis or neuropathic pain, but their effects in inflammatory pain and related pathways are not completely understood. Several treatments potentiate the analgesic actions of δ-opioid receptor (DOR) agonists, but the role of H₂S in modulating their effects and expression during inflammatory pain remains untested. In C57BL/6J male mice with inflammatory pain provoked by subplantar injection of complete Freund's adjuvant, we evaluated: (1) the antiallodynic and antihyperalgesic effects of different doses of two slow-releasing H₂S donors, i.e., diallyl disulfide (DADS) and phenyl isothiocyanate (P-ITC) and their mechanism of action; (2) the pain-relieving effects of DOR agonists co-administered with H₂S donors; (3) the effects of DADS and P-ITC on the oxidative stress and molecular changes caused by peripheral inflammation. Results demonstrate that both H₂S donors inhibited allodynia and hyperalgesia in a dose-dependent manner, potentiated the analgesic effects and expression of DOR, activated the antioxidant system, and reduced the nociceptive and apoptotic pathways. The data further demonstrate the possible participation of potassium channels and the Nrf2 transcription factor signaling pathway in the pain-relieving activities of DADS and P-ITC. This study suggests that the systemic administration of DADS and P-ITC and local application of DOR agonists in combination with slow-releasing H₂S donors are two new strategies for the treatment of inflammatory pain.

Protective Role of 4-Octyl Itaconate in Murine LPS/D-GalN-Induced Acute Liver Failure via Inhibiting Inflammation, Oxidative Stress, and Apoptosis

Oxidative stress, inflammation, and apoptosis are crucial in the pathogenesis of acute liver failure (ALF). 4-Octyl itaconate (OI) showed antioxidative and anti-inflammatory properties in many disease models. However, its role in lipopolysaccharide- (LPS-)/D-galactosamine- (D-GalN-) induced ALF is still not investigated. Here, we established an ALF murine model induced by LPS/D-GalN administration. And we found that OI improved survival rate in the murine ALF model. Our results also showed that OI alleviated LPS/D-GalN-induced hepatic histopathological injury and reduced the serum activities of alanine transaminase and aspartate transaminase. Moreover, OI reduced serum levels of proinflammatory cytokines such as monocyte chemotactic protein-1, tumor necrosis factors-α, and interlukin-6. Additionally, OI mitigated oxidative stress and alleviated lipid peroxidation in a murine model of ALF. This was evaluated by a reduction of thiobarbituric acid reactive substances (TBARS) in liver tissues. In addition, OI increased the ratio of reduced glutathione/oxidized glutathione and the activities of antioxidant enzymes including catalase and superoxide dismutase. Moreover, the apoptosis of hepatocytes in the liver was inhibited by OI. Furthermore, we found that OI inhibited LPS-induced nuclear translocation and activation of factor-kappa B (NF-κB) p65 in macrophages which could be inhibited by OI-induced activation of nuclear factor erythroid-2-related factor (Nrf2) signaling. Additionally, D-GalN-induced reactive oxygen species (ROS) generation and apoptosis in hepatocytes were inhibited by OI-induced activation of Nrf2 signaling. Therefore, the underlying mechanism for OI's protective effect in LPS/D-GalN-induced ALF may be associated with deactivation of NF-κB signaling in macrophages to reduce inflammation and inhibition of ROS-related hepatocyte apoptosis by activating Nrf2. In conclusion, OI showed a protective role in LPS/D-GalN-induced ALF by reducing inflammation, enhancing antioxidant capacity, and inhibiting cell apoptosis.

Fenofibrate, a peroxisome proliferator-activated receptor-alpha agonist, blocks steatosis and alters the inflammatory response in a mouse model of inflammation-dioxin interaction

2,3,7,8-Tetrachlorodibenzo-p-dioxin (dioxin; TCDD) is an environmental contaminant that elicits a variety of toxic effects, many of which are mediated through activation of the aryl hydrocarbon receptor (AhR). Interaction between AhR and the peroxisome proliferator-activated receptor-alpha (PPAR-α), which regulates fatty acid metabolism, has been suggested. Furthermore, with recognition of the prevalence of inflammatory conditions, there is current interest in the potential for inflammatory stress to modulate the response to environmental agents. The aim of this work was to assess the interaction of TCDD with hepatic inflammation modulated by fenofibrate, a PPAR-α agonist. Female, C57BL/6 mice were treated orally with vehicle or fenofibrate (250 mg/kg) for 13 days, and then were given vehicle or 30 μg/kg TCDD. Four days later, the animals received an i.p. injection of lipopolysaccharide-galactosamine (LPS-GalN) (0.05x10⁷ EU/kg and 500 mg/kg, respectively) to incite inflammation, or saline as vehicle control. After 4 h, the mice were euthanized, and blood and liver samples were collected for analysis. Livers of animals treated with TCDD with or without LPS-GalN had increased lipid deposition, and this effect was blocked by fenofibrate. In TCDD/LPS-GalN-treated mice, fenofibrate caused an increase in plasma activity of alanine aminotransferase, a marker of hepatocellular injury. TCDD reduced LPS-GalN-induced apoptosis, an effect that was prevented by fenofibrate pretreatment. LPS-GalN induced an increase in the concentration of interleukin-6 in plasma and accumulation of neutrophils in liver. TCDD exposure enhanced the former response and inhibited the latter one. These results suggest that fenofibrate counteracts the changes in lipid metabolism induced by TCDD but increases inflammation and liver injury in this model of inflammation-TCDD interaction.

The hepatoprotective efficacy and biological mechanisms of three phenylethanoid glycosides from cistanches herba and their metabolites based on intestinal bacteria and network pharmacology

Echinacoside (ECH), acteoside (ACT), and isoacteoside (ISAT), the typical phenylethanoid glycosides (PhGs) in cistanches herba, have various pharmacological activities. However, the ECH, ACT and ISAT have extremely low oral bioavailability, which is related to their metabolism under the intestinal flora. Previous studies showed that intestinal metabolites were the hepatoprotective substances in vivo, but the research on whether PhGs has effects without intestinal bacteria has not been studied. In this paper, ECH, ACT and ISAT were incubated with human or rat intestinal bacteria for 36 h. After incubating with human bacteria for 36 h, three prototype compounds were not detected and were mainly biotransformed to 3-HPP and HT. In the network pharmacology, a total of 6 common targets were obtained by analysing the prototypes, the metabolites and the liver injury. It was found that the combinations of three metabolites and common targets were more stable than those of the prototypes and common targets by molecular docking. Meanwhile, hepatocellular apoptosis, proliferation, inflammation and oxidative responses might play important roles in the mechanisms of the metabolites exerting hepatoprotective activities. Then normal and pseudo-sterile mice experiments were adopted to further compare the hepatoprotective activities of prototypes and metabolites. Animal experiment results showed that the prototypes and the metabolites in the normal mice had significantly hepatoprotective activity. Interestingly, in the pseudo-germfree mice, the metabolites showed significant hepatoprotective effect, but the prototypes had not effect. It indicated that the prototype cannot exert liver protective activity without the effect of intestinal bacteria.

Melatonin Ameliorates LPS-Induced Testicular Nitro-oxidative Stress (iNOS/TNFα) and Inflammation (NF-kB/COX-2) via Modulation of SIRT-1

Lipopolysaccharide (LPS) - an endotoxin that is being extensively used in laboratory to mimic microbial infection that adversely affects male fertility. This study investigated the protective effects of melatonin on LPS-induced testicular nitro-oxidative stress, inflammation, and associated damages in the testes of male golden hamsters, Mesocricetus auratus. Hamsters were administered with melatonin and LPS for 7 days. Testes of LPS treated hamsters showed degenerative changes (appearance of vacuoles, exfoliation, and depletion of germ cells in the seminiferous tubules), adverse effects on spermatogenesis (sperm count and viability), and steroidogenesis (declined serum and testicular testosterone). Furthermore, LPS treatment decreased melatonin content, melatonin receptor (MT1), and antioxidant potential (catalase and SOD), and simultaneously increased nitro-oxidative stress (CRP, nitrate, TNFα). LPS upregulated NF-kB, COX-2, and iNOS expressions to increase testicular inflammatory load that resulted in the decrease of germ cell proliferation and survival, thus culminating into germ cell apoptosis as indicated by AO-EB staining and caspase-3 expression. Administration of melatonin with LPS showed improved testicular histoarchitecture, sperm parameters, and testosterone level. Melatonin increased testicular antioxidant status (SOD, catalase) to counteract the LPS-induced testicular ROS and thus reduced testicular nitro-oxidative stress. Furthermore, melatonin treatment upregulated testicular SIRT-1 expression to inhibit LPS-induced inflammatory proteins, i.e., NF-kB/COX-2/iNOS expression. The rescue effect of melatonin was further supported by increased germ cell survival (Bcl-2), proliferation (PCNA), and declined apoptosis (caspase-3). In conclusion, our result demonstrated that melatonin rescued testes from LPS-induced testicular nitro-oxidative stress, inflammation, and associated damages by upregulation of SIRT-1.

Hepatoprotective effects of extracts, fractions and compounds from the stem bark of Pentaclethra macrophylla Benth: Evidence from in vitro and in vivo studies

AIM

To identify the bioactive hepatoprotective components of the ethanol extract of Pentaclethra macrophylla stem bark using in vitro and in vivo approaches.

METHODS

The bioguided-fractionation of the ethanol extract was based on the substances' capacity to prevent in vitro, the lipid peroxidation of hepatocytes' membranes induced by hydrogen peroxide. For the in vivo hepatoprotective test, mice were treated orally with the ethyl acetate (EtOAc) fraction of the ethanol extract at doses of 50 and 75 mg/kg/day for one week and subjected to d-galactosamine/lipopolysaccharide (GaIN/LPS)-induced hepatotoxicity. Blood samples were collected for alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), TNF-α and IL-1β assays. The liver was harvested for histological and biochemical (proteins, glutathione (GSH), catalase and superoxide dismutase (SOD)) analysis.

RESULTS

The ethanol extract and fractions induced concentration-dependent inhibition of lipid peroxidation (IC50: 3.21-48.90 μg/mL) greater than that of silymarin (IC50: 117.4 μg/mL). The purification of the sub-fractions of EtOAc fraction yielded: (7R)-7-hydroxyhexacosanoic acid (1), (7R)-1-(7-hydroxyhexacosanoyl) glycerol (2), bergenin (3), 11-O-galloylbergenin (4), 2-hydroxymethyl-5-(2-hydroxypropan-2-yl)phenol (5), β-sitosterol 3-O-β-d-glucopyranosyl (6) and β-sitosterol (7)), among which 11-O-galloylbergenin (IC50:1.8 μg/mL) was the most effective. The EtOAc fraction significantly reduced the serum level of ALAT, ASAT and TNF-α in vivo. This EtOAc fraction increased the liver protein content and protected the liver against structural damages, but did not boost the endogenous antioxidant parameters.

CONCLUSION

The stem bark of Pentaclethra macrophylla possesses hepatoprotective effects that may result from its capacity to inhibit lipid peroxidation and could be attributed to its active components 3, 4 and 2.

A Novel Antioxidant Protects Against Contrast Medium-Induced Acute Kidney Injury in Rats

Many studies proposed that oxidative stress and apoptosis are key mechanisms in the pathogenesis of contrast-induced acute kidney injury (CI-AKI). Xylose-pyrogallol conjugate (XP) is an original effective antioxidant that showed decent antioxidant and anti-apoptosis effect before. Thus the therapeutic effect and mechanism of XP in preventing CI-AKI in the short and long term were investigated in this research. Renal function and histological grade were evaluated to determine the severity of renal injury. Kidney samples were then collected for the measurement of oxidative stress markers and the detection of apoptosis. Transmission electron microscopy (TEM) and western blot of mitochondrial protein were utilized for the analysis of the mitochondrial conditions. The results demonstrated that the CI-AKI rats caused a significant decrease in renal function accompanied by a remarkable increase in Malondialdehyde (MDA), bax, caspase-3, cytochrome c (Cyt C) level, TdT-mediated dUTP nick end labeling (TUNEL) positive apoptotic cells, and damaged mitochondria, while a decline in antioxidase activities and mitochondrial superoxide dismutase 2 (SOD2) expression compared with the control rats. However, when XP (50 or 100 or 200 mg/kg/day) was given orally for consecutive 7 days before CI-AKI modeling, XP (200 mg/kg) showed a better capability to restore renal dysfunction, histopathological appearance, the level of apoptosis, mitochondrial damage, oxidative stress, and fibrosis generation without interference in computed tomographic imaging. Our study indicated that antioxidant XP played a nephroprotective role probably via antiapoptotic and antioxidant mechanisms. Besides, XP may regulate the mitochondria pathway via decreasing the ratio of bax/bcl-2, inhibiting caspase-3 expression, cytochrome c release, and superoxide dismutase 2 activity. Overall, XP as a high-efficient antioxidant may have the potentials to prevent CI-AKI.

Lauric acid ameliorates lipopolysaccharide (LPS)-induced liver inflammation by mediating TLR4/MyD88 pathway in Sprague Dawley (SD) rats

BACKGROUND

Lipopolysaccharide (LPS) is an endotoxin that leads to inflammation in many organs, including liver. It binds to pattern recognition receptors, that generally recognise pathogen expressed molecules to transduce signals that result in a multifaceted network of intracellular responses ending up in inflammation. Aim In this study, we used lauric acid (LA), a constituent abundantly found in coconut oil to determine its anti-inflammatory role in LPS-induced liver inflammation in Sprague Dawley (SD) rats.

METHOD

Male SD rats were divided into five groups (n = 8), injected with LPS and thereafter treated with LA (50 and 100 mg/kg) or vehicle orally for 14 days. After fourteen days of LA treatment, all the groups were humanely killed to investigate biochemical parameters followed by pro-inflammatory cytokine markers; tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β. Moreover, liver tissues were harvested for histopathological studies and evaluation of targeted protein expression with western blot and localisation through immunohistochemistry (IHC).

RESULTS

The study results showed that treatment of LA 50 and 100 mg/kg for 14 days were able to reduce the elevated level of pro-inflammatory cytokines, liver inflammation, and downregulated the expression of TLR4/NF-κB mediating proteins in liver tissues.

CONCLUSION

These findings suggest that treatment of LA has a protective role against LPS-induced liver inflammation in rats, thus, warrants further in-depth investigation through mechanistic approaches in different study models.

S-allyl cysteine, an active ingredient of garlic, attenuates acute liver dysfunction induced by lipopolysaccharide/ d-galactosamine in mouse: Underlying mechanisms

In the present study, beneficial effect of S-allyl cysteine (SAC) was evaluated in the lipopolysaccharide/d-galactosamine (LPS/d-Gal) model of acute liver injury (ALI). To mimic ALI, LPS and d-Gal (50 μg/kg and 400 mg/kg, respectively) were intraperitoneally administered and animals received SAC per os (25 or 100 mg/kg/d) for 3 days till 1 hour before LPS/d-Gal injection. Pretreatment of LPS/d-Gal group with SAC-lowered activities of alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase and partially reversed inappropriate alterations of hepatic oxidative stress- and inflammation-related biomarkers including liver reactive oxygen species, malondialdehyde, and hepatic activity of the defensive enzyme superoxide dismutase, ferric reducing antioxidant power (FRAP), toll-like receptor-4 (TLR4), cyclooxygenase 2, NLR family pyrin domain containing 3 (NLRP3), caspase 1, nuclear factor κB (NF-κB), interleukin 1β (IL-1β), IL-6, tumor necrosis factor-α, and myeloperoxidase activity. Additionally, SAC was capable to ameliorate apoptotic biomarkers including caspase 3 and DNA fragmentation. In summary, SAC can protect liver against LPS/d-Gal by attenuation of neutrophil infiltration, oxidative stress, inflammation, apoptosis, and pyroptosis which is partly linked to its suppression of TLR4/NF-κB/NLRP3 signaling.

MiR-195 suppression alleviates apoptosis and oxidative stress in CCl4-induced ALI in mice by targeting Pim-1

BACKGROUND

Acute liver injury (ALI) is associated with the oxidative stress and apoptosis in liver. Recent studies have shown that miR-195, a critical member of miR-15 family, has modulated the apoptosis in various organic diseases. However, it is elusive whether miR-195 regulation exert a hepatic ameliorative effect on ALI by the suppression of apoptosis and oxidative stress levels. We aimed to explore the regulated role of miR-195 in acute liver injury via the current study.

METHODS

C57BL/6 J mice (male, seven-week, 18-20 g) were administrated intraperitoneal injection with tetrachloromethane (CCl₄) to induce ALI. miR-195 inhibitor or mimics loaded in lentivirus vectors (miR-195 INH or MMC) and Pim-1 loaded in Adeno-associated viral vectors (AAV-Pim-1) were respectively delivered into mouse tail intravenous to establish silence or overexpression of miR-195 and overexpression of Pim-1. Western blotting, Reverse Transcription-Polymerase Chain Reaction (RT-PCR), enzyme linked immunosorbent assay (ELISA) technique, Immunohistochemistry (IHC) and Hematoxylin-eosin (H&E) staining were conducted to measure miR-195 and Pim-1 expression, apoptosis and oxidative stress levels, histological and functional change.

RESULTS

We found that the expression of miR-195 markedly increased in CCl4-induced ALI. Besides, we demonstrated that the silence of miR-195 attenuated the apoptosis and oxidative stress via up-regulating Pim-1 in CCl4-induced ALI. Moreover, the inhibition of miR-195 protected the integrity and function of liver tissue.

CONCLUSIONS

The above results showed that the suppression of miR-195 ameliorated ALI through inhibiting apoptosis and oxidative stress via targeting Pim-1. Our research provided a novel scheme that the miR-195 modulation in process of ALI may be an effective therapy method and verifies a promising target for diagnostic and therapeutic strategy of miRNAs.

4-hydroxybenzo[d]oxazol-2(3H)-one ameliorates LPS/D-GalN-induced acute liver injury by inhibiting TLR4/NF-κB and MAPK signaling pathways in mice

The purpose of this study was to synthesize 4-hydroxybenzo[d]oxazol-2(3H)-one (HBO) and to investigate its protective effects on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury. HBO (C₇H₅O₃N) was synthesized based on 2-nitro-resorcinol and identified by physicochemical analysis. In the animal experiment, mice were pretreated with HBO (50, 100, 200 mg/kg) for 10 days. At the end of pretreatment, the animals were injected with LPS (10 µg/kg)/D-GalN (700 mg/kg). The results showed that HBO significantly alleviated liver injury induced by LPS/D-GalN in mice. It remarkably decreased inflammatory response by reducing the levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Moreover, HBO notably attenuated hepatocyte apoptosis by inhibiting the release of Cytochrome C (Cyt C) from mitochondria into the cytoplasm and regulating the expression of B-cell lymphoma-2 (Bcl-2) family. Furthermore, the result showed that HBO inhibited the expressions of nuclear factor kappa-B p50 (NF-κBp50), toll-like receptor 4 (TLR4), and myeloid differentiation factor 88 (MyD88), as well as the phosphorylation of inhibitor of nuclear factor kappa-B (IκB), inhibitor of nuclear factor kappa-B kinase-α/β (IKK-α/β), nuclear factor kappa-B p65 (NF-κBp65), suggesting that HBO had a certain influence on the TLR4/NF-κB pathway. In addition, the mitogen-activated protein kinase (MAPK) signaling pathway was also affected by HBO, as evidenced by the decrease in the phosphorylation levels of extracellular regulated protein kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38). In conclusion, our study suggested that HBO could protect against LPS/D-GalN-induced liver injury, moreover, treatment with HBO appeared to be capable of further regulating the TLR4/NF-κB and MAPK signaling pathways.

Sedum sarmentosum Bunge extract ameliorates lipopolysaccharide- and D-galactosamine-induced acute liver injury by attenuating the hedgehog signaling pathway via regulation of miR-124 expression

Background

Sedum sarmentosum is traditionally used to treat various inflammatory diseases in China. It has protective effects against acute liver injury, but the exact mechanism of such effects remains unclear. This study investigated the protective effects of S. sarmentosum extract on lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced acute liver injury in mice and the mechanism of such effects.

Methods

Mice were randomly divided into control, treatment, model, and model treatment groups. Acute liver injury was induced in model mice via intraperitoneal injection of LPS and D-GalN with doses of 10 μg/kg of LPS and 500 mg/kg, respectively. The mRNA expression levels of miR-124, Hedgehog, Patched (Ptch), Smoothened (Smo), and glioma-associated oncogene homolog (Gli) in liver tissues were determined through RT-PCR, and the protein levels of Hedgehog, Ptch, Smo, Gli, P13k, Akt, HMGB1, TLR4, IkB-α, p-IkB-α, and NF-kB65 were evaluated via Western blot analysis. The serum levels of IL-6, TNF-α, CRP, IL-12, and ICAM-1 were determined via ELISA. TLR4 and NF-κBp65 activity and the levels of DNA-bound NF-KB65 and TLR4 in LPS/D-GalN-induced liver tissues were also determined. We recorded the time of death, plotted the survival curve, and calculated the liver index. We then observed the pathological changes in liver tissue and detected the levels of liver enzymes (alanine aminotransferase [ALT] and aspartate transaminase [AST]) in the serum and myeloperoxidase (MPO) and plasma inflammatory factors in the liver homogenate. Afterward, we evaluated the protective effects of S. sarmentosum extracts on acute liver injury in mice.

Results

Results showed that after S. sarmentosum extract was administered, the expression level of miR-124 increased in liver tissues. However, the protein expression levels of Hedgehog, Ptch, Smo, Gli, P13k, p-Akt, HMGB1, TLR4, p-IκB-α, and NF-κB65 and the mRNA expression levels of Hedgehog, Ptch, Smo, and Gli decreased. The MPO level in the liver, the IL-6, TNF-α, CRP, IL-12, and MMP-9 levels in the plasma, and the serum ALT and AST levels also decreased, thereby reducing LPS/D-GalN-induced liver injury and improving the survival rate of liver-damaged animals within 24 h.

Conclusions

S. sarmentosum extract can alleviate LPS/D-GalN-induced acute liver injury in mice and improve the survival rate of mice. The mechanism may be related to the increase in miR-124 expression, decrease in Hedgehog and HMGB1 signaling pathway activities, and reduction in inflammatory responses in the liver. Hedgehog is a regulatory target for miR-124.

Studies on the potential link between antidepressant effect of Xiaoyao San and its pharmacological activity of hepatoprotection based on multi-platform metabolomics

ETHNOPHARMACOLOGICAL RELEVANCE

In traditional Chinese medicine (TCM) theory, depression is considered to be "liver qi stagnation", and relieving "liver qi stagnation" is regarded as an effective method for treating depression. Xiaoyao San (XYS) is a well-known TCM formula for the treatment of depression by relieving "liver qi stagnation". This formula consists of Radix Paeoniae Alba (Paeonia lactiflora Pall.), Radix Bupleuri (Bupleurum chinense DC.), Poria (Poria cocos (Schw.) Wolf), Rhizoma Atractylodis Macrocephalae (Atractylodes macrocephala Koidz.), Radix Angelicae Sinensis (Angelica sinensis (Oliv.) Diels), Radix Glycyrrhizae (Glycyrrhiza uralensis Fisch.), Rhizoma Zingiberis Recens (Zingiber officinale Roscoe) and Herba Menthae Haplocalycis (Mentha haplocalyx Briq.).

AIM OF THE STUDY

Several studies have suggested that depression is associated with liver injury. XYS was a well-known TCM formula for the treatment of depression and liver stagnancy. However, it was still unknown whether the antidepressant effect of XYS is related to the pharmacological activity of hepatoprotection. The aim of this study was to elucidate the potential link between the antidepressant and hepatoprotective effect of XYS.

MATERIALS AND METHODS

A depression rat model was established by the CUMS (chronic unpredictable mild stress) procedure. The antidepressant effect of XYS was assessed by the behavioral indicators, and the hepatoprotective effect of XYS was evaluated through biochemical assays. ¹H-NMR and LC/MS-based liver metabolomics were performed to discover key metabolic pathways involved in the antidepressant and hepatoprotective effects of XYS. Further, the key pathway was validated using commercial kits.

RESULTS

The results demonstrated that XYS pretreatment could significantly improve the depressive symptom induced by CUMS. More importantly, the results demonstrated that liver injury was observed in the CUMS model rats, and XYS had a hepatoprotective effect by reducing the activities of AST and ALT in serum, increasing the levels of SOD and GSH-Px and reducing the contents of MDA, IL-6, and IL-1β in the liver. In addition, the NMR and LC/MS-based metabolomics results indicated that XYS improved 23 of the 35 perturbed potential liver biomarkers that were induced by CUMS. Among them, 9 biomarkers were significantly correlated with both depression and liver pathology, according to Pearson correlation analysis. Metabolic pathway analyses of these 9 biomarkers showed that glutamine and glutamate metabolism were the most important metabolic pathways. Furthermore, to verify glutamine and glutamate metabolism, the levels of glutamine and glutamate, and the activity of glutamine synthetase (GS) and glutaminase (GLS) were quantitatively determined in the liver by commercial kits, and these results were consistent with the metabolomics results.

CONCLUSIONS

XYS could significantly improve the depressive and liver injury symptoms induced by CUMS. The metabolomics results indicate that the regulation of glutamine and glutamate metabolism to maintain the balance of ammonia and promote energy metabolism is a potential junction between the antidepressant and hepatoprotective effects of XYS.

Helenalin from Centipeda minima ameliorates acute hepatic injury by protecting mitochondria function, activating Nrf2 pathway and inhibiting NF-κB activation

Acute liver injury is a life-threatening syndrome that often caused by hepatocyte damage and is characterized by inflammatory and oxidative responses. Helenalin isolated from Centipeda minima (HCM) has been found to have anti-inflammatory and anti-oxidative effects. Here, this study aimed to investigate the effects and underlying mechanisms of HCM on Lipopolysaccharide/D-Galactosamine (LPS/D-GalN)-induced acute liver injury. Mice were intragastrically administered with various dose of HCM for 10 days; 2 h after the final treatment, the mice were injected with 50 μg/kg LPS and 800 mg/kg D-GalN. The histopathological changes, hepatocyte apoptosis, serum cytokines, oxidative stress and inflammatory cytokines were assessed. The results showed that HCM significantly ameliorated the hepatic injury, as evidenced by the attenuation of histopathological changes and the decrease in serum aminotransferase and total bilirubin activities. HCM markedly decreased hepatocyte apoptosis by modulating the mitochondria-dependent pathway, including the increase in the Bcl-2/Bax ratio, the inhibition of caspase-3, -8 and -9, and the inhibition of cytochrome C release. Moreover, HCM strongly alleviated oxidative stress, lipid peroxidation and reactive oxygen species (ROS) generation by activating the Nrf2 signaling pathway. In addition, HCM significantly attenuated inflammatory cytokines including TNF-α, IL6 and IL-1β as well as NO production by inhibiting TLR4 signaling transduction and NF-κB activation. In conclusion, HCM protects hepatocytes from damage induced by LPS/D-GalN, which may contribute to its ability to alleviate hepatocyte apoptosis by protecting the mitochondrial function, inhibit oxidative stress by activating the Nrf2 pathway, and attenuate inflammation by inhibiting NF-κB activation. This study demonstrates that HCM may be developed as a potential agent for the treatment of acute liver failure.

Dexmedetomidine-mediated protection against septic liver injury depends on TLR4/MyD88/NF-κB signaling downregulation partly via cholinergic anti-inflammatory mechanisms

BACKGROUND

Uncontrolled inflammatory responses exacerbate the pathogenesis of septic acute liver injury (ALI), posing a lethal threat to the host. Dexmedetomidine (DEX) has been reported to possess protective properties in inflammatory conditions. This study aimed to investigate whether DEX pretreatment exhibits hepatoprotection against ALI induced by lipopolysaccharide (LPS) in rats and determine its possible molecular mechanism.

METHODS

Septic ALI was induced by intravenous injection of LPS. The rats received DEX intraperitoneally 30 min before LPS administration. α-Bungarotoxin (α-BGT), a specific α7 nicotinic acetylcholine receptor (α7nAChR) antagonist, was administered intraperitoneally 1 h before LPS exposure. The role of the vagus nerve was verified by performing unilateral cervical vagotomy or sham surgery before sepsis.

RESULTS

The expression of α7nAChR, toll-like receptor 4 (TLR4), high mobility group box 1 (HMGB1), and cleaved caspase-3 increased, peaking 24 h during sepsis. DEX enhanced α7nAChR activation and reduced TLR4 expression upon challenge with LPS. DEX significantly prevented LPS-induced ALI, which was associated with increased survival, the mitigation of pathological changes, the attenuation of inflammatory cytokine expression and apoptosis, and the downregulation of TLR4/MyD88/NF-κB pathway. Moreover, the hepatoprotective effect of DEX was abolished by α-BGT. Further investigation established that vagotomy, compared to sham surgery, triggered more severe pathogenic manifestations and higher proinflammatory cytokine levels. The inhibitory effects of DEX were shown in sham-operated rats but not in vagotomized rats.

CONCLUSIONS

Our data highlight the pivotal function of α7nAChR and intact vagus nerves in protecting against LPS-induced ALI through inhibiting the TLR4/MyD88/NF-κB signaling pathway upon pretreatment with DEX.

Pretreatment with Salvia miltiorrhiza Polysaccharides Protects from Lipopolysaccharides/d-Galactosamine-Induced Liver Injury in Mice Through Inhibiting TLR4/MyD88 Signaling Pathway

The study was conducted to investigate the protective effects of Salvia miltiorrhiza polysaccharides (SMPs) on lipopolysaccharides (LPS)/d-galactosamine (d-GalN)-induced liver injury in mice and its mechanism. Seventy-two mice were allocated to 6 groups of 12 each, that is, the untreated control group, the liver injury model group, the Bifendate group (Bifendate 200 mg/kg/day), and 3 SMP-treated groups at low (250 mg/kg/day), medium (500 mg/kg/day), and high doses (750 mg/kg/day). After 12 days oral treatment, liver injury was induced with LPS/d-GalN, and 1 h later the mice were sacrificed for a series of analyses. The results showed that SMPs significantly alleviated pathological changes in the hepatic tissue. Compared with the untreated control group, the messenger RNA (mRNA) levels of lipopolysaccharide-binding protein (LBP), cluster of differentiation 14 (CD14), myeloid differentiation factor 2 (MD-2), toll-like receptor 4 (TLR4), and myeloid differentiation primary response protein 88 (MyD88) detected by quantitative real-time polymerase chain reaction (qRT-PCR), the protein levels of TLR4, MyD88, phosphorylated inhibitor of nuclear factor kappa-B kinase alpha/beta (P-IKK-α/β), phosphorylated inhibitor of NF-κB alpha (P-IκB-α) and phosphorylated P65 (P-P65) detected by Western blot, the levels of C-X-C motif chemokine 10 (CXCL-10) and Intercellular Adhesion Molecule 1 (ICAM-1) detected by immunohistochemistry, and the concentrations of tumor necrosis factor alpha (TNF-α) and interleukin 1 beta (IL-1β) detected by enzyme-linked immunosorbent assay of liver injury model group were increased significantly (P < 0.01). Compared with liver injury model group, the mRNA levels of LBP, CD14, MD-2, TLR4, and MyD88; protein levels of TLR4, MyD88, P-IKK-α/β, P-IκB-α, and P-P65; levels of CXCL-10 and ICAM-1; and the concentrations of TNF-α and IL-1β of SMP groups and Bifendate group were decreased significantly (P < 0.01 or P < 0.05). In conclusion, SMPs can effectively inhibit TLR4/MyD88 inflammatory signaling pathway of LPS/d-GalN-induced liver injury in mice, and it may be part of the mechanism by which SMPs relieve excessive inflammation in the liver of mice.

Hydrogen Sulfide as a Novel Regulatory Factor in Liver Health and Disease

Hydrogen sulfide (H₂S), a colorless gas smelling of rotten egg, has long been recognized as a toxic gas and environment pollutant. However, increasing evidence suggests that H₂S acts as a novel gasotransmitter and plays important roles in a variety of physiological and pathological processes in mammals. H₂S is involved in many hepatic functions, including the regulation of oxidative stress, glucose and lipid metabolism, vasculature, mitochondrial function, differentiation, and circadian rhythm. In addition, H₂S contributes to the pathogenesis and treatment of a number of liver diseases, such as hepatic fibrosis, liver cirrhosis, liver cancer, hepatic ischemia/reperfusion injury, nonalcoholic fatty liver disease/nonalcoholic steatohepatitis, hepatotoxicity, and acute liver failure. In this review, the biosynthesis and metabolism of H₂S in the liver are summarized and the role and mechanism of H₂S in liver health and disease are further discussed.