Protective effects of protostemonine on LPS/GalN-induced acute liver failure: Roles of increased hepatic expression of heme oxygenase-1

Kupffer-Cell-Targeted Carboxylesterase 1f Knockdown Deteriorates Lipopolysaccharide/D-Galactosamine-Induced Acute Liver Failure Through Regulating Cellular Polarization in Mice

Background: Aims: Carboxylesterase (Ces)1f is implicated in protection against hepatic inflammation, but it is unclear whether the enzyme has an influence in polarization of Kupffer cells (KCs), the innate immune cells mediating hepatic inflammatory injury including acute liver failure (ALF). In the present study, we aim to explore KC polarization induced by Ces1f in mice with lipopolysaccharide/D-galactosamine (LPS/D-GalN)-induced ALF. Methods: We adopted a novel delivery system, β-1,3-D-glucan-encapsulated Endoporter-siRNA particles, to specifically target KC Ces1f knockdown via tail vein injection in mice. Results: Ces1f knockdown increased LPS/D-GalN-induced lethality as well as serum levels of alanine and aspartate transaminases, deteriorated hepatic inflammatory injury, and imbalanced hepatic oxidative stress molecules including myeloperoxidase, malondialdehyde, and superoxide dismutase in ALF. Ces1f knockdown also increased the levels of proinflammatory cytokines (tumor necrosis factor-α and interleukin-6) and decreased the levels of anti-inflammatory cytokine (interleukin-10) in LPS/D-Gal-induced ALF. Ces1f knockdown promoted KC M1 phenotype and marker expression (including CD86 and interleukin-1β), but inhibited M2 phenotype and marker expression (including CD163, CD206, and Arginase 1). Conclusions: Our results suggest that Ces1f plays a hepatoprotective role through regulating KC polarization, which might contribute to anti-inflammatory and antioxidative effects in LPS/D-Gal-induced ALF mice.

Bromelain ameliorates D-galactosamine-induced acute liver injury: role of SIRT1/LKB1/AMPK, GSK3β/Nrf2 and NF-κB p65/TNF-α/caspase-8, -9 signalling pathways

OBJECTIVES

The present research focused on estimating, for the first time, the potential protective effects of bromelain against D-galactosamine-induced acute liver injury in rats as well as identifying the possible underlying mechanisms.

METHODS

Silymarin (100 mg/kg/day, p.o.) as a reference drug or bromelain (20 and 40 mg/kg/day, p.o.) were administered for 10 days, and on the 8th day of the experiment, a single dose of galactosamine (400 mg/kg/i.p.) induced acute liver injury.

KEY FINDINGS

Pretreatment with bromelain improved liver functions and histopathological alterations induced by galactosamine. Bromelain ameliorated oxidative stress by inducing SIRT1 protein expression and increasing LKB1 content. This resulted in phosphorylating the AMPK/GSK3β axis, which stimulated Nrf2 activation in hepatic cells and thus increased the activity of its downstream antioxidant enzymes [HO-1 and NQO1]. Besides, bromelain exerted significant anti-apoptotic and anti-inflammatory effects by suppressing hepatic contents of TNF-α, NF-κB p65, as well as caspase-8 and caspase-9. The protective effects of bromelain40 were proved to be better than silymarin and bromelain20 in most of the assessed parameters.

CONCLUSIONS

Our results highlight the significant hepatoprotective effects of bromelain against acute liver injury through modulation of SIRT1/LKB1/AMPK, GSK3β/Nrf2 signalling in addition to NF-κB p65/TNF-α/ caspase-8 and -9 pathway.

Protective activity of purpurin against d-galactosamine and lipopolysaccharide-induced hepatorenal injury by upregulation of heme oxygenase-1 in the RBC degradation cycle

Acute liver failure, associated with oxidative stress and sustained inflammation is the major clinical manifestation of liver diseases with a high mortality rate due to limited therapeutic options. Purpurin is a bioactive compound of Rubia cordifolia that has been used in textile staining, as a food additive, and as a treatment of multiple chronic and metabolic diseases associated with inflammation and oxidative stress. The present work aimed to investigate the protective efficacy of purpurin against hepatorenal damage. Thirty-six female albino rats were equally assigned into six groups. Purpurin was administered orally once a day for 6 days at doses of 05, 10, and 20 mg/kg, respectively. Intraperitoneal injection of lipopolysaccharide (50 μg/kg) was administered to the animals on 6th day evening, 1 h after d-galactosamine (300 mg/kg) administration to induce hepatorenal injury. The results revealed that purpurin alleviated alterations in serological and hematological parameters as well as restored histoarchitectural and cellular integrity of the liver and kidney. Purpurin restored superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase, and glutathione content in hepatorenal tissues. Accompanied by the diminution of increased bilirubin and biliverdin, purpurin also diminished total cholesterol, triglyceride, and lipid peroxidation in hepatorenal tissues. Purpurin markedly attenuated the elevation of CYP2E1, restored glutathione-S-transferase, and prevented DNA damage in hepatorenal tissues. Purpurin reduced iron overload by reducing heme depletion and recycling of ferritin and hemosiderin. It also reinforced biliverdin reductase, heme oxygenase-1 to employ hepatorenal protection by regulating antioxidant enzymes and other pathways that produced NADPH. Thus, it may be concluded that purpurin has protective potential against acute hepatorenal injury.

Gallic Acid Protects from Acute Multiorgan Injury Induced by Lipopolysaccharide and D-galactosamine

BACKGROUND

Secondary metabolites of plants, the polyphenols, play a vital role in protection from many health problems in human beings. Structurally favored phytochemicals may be studied to protect multiorgan injury. At pharmacological doses, gallic acid is nontoxic to mammals and is generally absorbed in the intestine.

AIMS

In this present study, gallic acid was evaluated for its protective efficacy against Lipo Polysaccharide (LPS) and d-Galactosamine (D-GalN) induced multiorgan injury, i.e., liver, kidney and brain.

METHODS

Three different doses of gallic acid (5, 10 and 20 mg/kg p.o.) were administered to the experimental animals for 6 consecutive days, followed by exposure to LPS (50 μg/kg I.P.) and D-GalN (300 mg/kg I.P.) on the 6th day.

RESULTS

Exposure to LPS and D-GalN resulted in increased oxidative stress and proinflammatory cytokines. Altered hematology and serology due to LPS and D-GalN were restored towards control by gallic acid. Declined antioxidants such as reduced glutathione, superoxide dismutase and catalase due to injurious effects of LPS and D-GalN were rejuvenated by gallic acid.

DISCUSSION

Exposure to LPS and D-GalN severely increased lipid peroxidation, CYP2E1 activity and tissue lipids while lowered protein content. Gallic acid restored all these parameters towards control in dose dependent manner and 20 mg/kg dose provided the best protection. Histological study showed improved histoarchitecture of liver, kidney and brain that supported biochemical endpoints.

CONCLUSION

Gallic acid minimized oxidative stress and provided best protection at 20 mg/kg dose against LPS and D-GalN induced multi organ acute injury.

The hepatoprotective effect of myricetin against lipopolysaccharide and D-galactosamine-induced fulminant hepatitis

Fulminant hepatitis (FH) is a severe liver disease characterized by extensive hepatic necrosis, oxidative stress, and inflammation. Myricetin (Myr), a botanical flavonoid glycoside, is recognized to exert antiapoptosis, anti-inflammatory, and antioxidant properties. In the current study, we focused on exploring the protective effects and underlying mechanisms of Myr against lipopolysaccharide (LPS) and D-galactosamine (D-GalN)-induced FH. These data indicated that Myr effectively protected from LPS/D-GalN-induced FH by lowering the mortality of mice, decreasing ALT and AST levels, and alleviating histopathological changes, oxidative stress, inflammation, and hepatic apoptosis. Moreover, Myr could efficiently mediate multiple signaling pathways, displaying not only the regulation of caspase-3/9 and P53 protein, inhibition of toll-like receptor 4 (TLR4)-nuclear factor-kappa B (NF-κB) activation, and -mitogen-activated protein kinase (MAPK), but also the increase of heme oxygenase-1 (HO-1) and nuclear factor-erythroid 2-related factor 2 (Nrf2) expression, as well as induction of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) phosphorylation in mice with LPS/D-GalN-induced FH. Importantly, our further results in vitro suggested that Myr remarkably attenuated H₂O₂-triggered hepatotoxicity and ROS generation, activated Keap1-Nrf2/HO-1 and AMPK/ACC signaling pathway. However, Myr-enhanced the expression of HO-1 and Nrf2 protein was reversed by Keap1-overexpression, Nrf2-null and AMPK inhibitor. Meanwhile, Myr-relieved hepatotoxicity excited by H₂O₂ was blocked by Nrf2-null and AMPK inhibitor. Taken together, Myr exhibits a protective role against LPS/D-GalN-induced FH by suppressing hepatic apoptosis, inflammation, and oxidative stress, likely involving in the regulation of apoptosis-related protein, TLR4-NF-κB/-MAPK and NLRP3 inflammasome, and AMPK-Nrf2/HO-1 signaling pathway.

Protostemonine alleviates heat-killed methicillin-resistant Staphylococcus aureus-induced acute lung injury through MAPK and NF-κB signaling pathways

Acute lung injury (ALI) and its most severe form acute respiratory distress syndrome (ARDS) caused by gram-positive bacteria threatens human life because effective treatments and medicines is unavailable. Protostemonine (PSN), an active alkaloid mainly isolated from the roots of Stemona sesslifolia, has anti-inflammatory effects on asthma and gram-negative bacteria-induced ALI. Here, we found that PSN exhibits anti-inflammatory effects and alleviates heat-killed methicillin-resistant Staphylococcus aureus (HKMRSA)-induced pneumonia. PSN treatment significantly attenuated HKMRSA-induced pathological injury, pulmonary neutrophil infiltration, tissue permeability and the production of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) in murine ALI model. In addition, PSN decreased the content of TNF-α, IL-1β, IL-6 and the expression of iNOS, as well as the production of NO in HKMRSA-induced bone marrow derived macrophages (BMDMs). Furthermore, treatment with PSN suppressed the activation of MAPKs (e.g. p38 MAPK, JNK and ERK) and NF-κB. Collectively, our results suggest that PSN ameliorates gram-positive bacteria-induced ALI in mice by inhibition of the MAPK and NF-κB signaling pathways, and our studies suggest that PSN might be a novel candidate for treating ALI/ARDS.

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.

Hepatoprotective effect of chiisanoside from Acanthopanax sessiliflorus against LPS/D-GalN-induced acute liver injury by inhibiting NF-κB and activating Nrf2/HO-1 signaling pathways

BACKGROUND

In China, Acanthopanax sessiliflorus is a delicious wild vegetable. It is also used to treat inflammation and pain. Chiisanoside (CSS) is the main constituent of the leaf of A. sessiliflorus. Combined use of lipopolysaccharide and d-galactosamine (LPS/D-GalN) can induce acute liver failure in human beings, and there are no reports on the protective effect of CSS against LPS/D-GalN-induced acute liver injury in mice.

RESULTS

Chiisanoside pretreatment evidently reduced the activities of alanine transaminase (ALT) and aspartate transaminase (AST) in the changes induced by LPS/D-GalN, and these histopathological changes induced by LPS/GalN were significantly weakened. Catalase (CAT), glutathione (GSH), and superoxide dismutase (SOD) activities increased, and malondialdehyde (MDA) activity decreased after CSS treatment compared with LPS/D-GalN treatment. Pretreatment with CSS also inhibited the expression levels of inflammatory factors. The administration of CSS prevented the phosphorylated expression of inhibitor kappa B (IκB) kinase, and led to a significant increase in heme oxygenase-1 (HO-1) expression and nuclear factor erythroid 2-related factor2 (Nrf2) nuclear translocation.

CONCLUSION

The protective effects of CSS are attributed to its antioxidative effect and inflammatory suppression in Nuclear factor kappa beta (NF-κB) and Nrf2/HO-1 signaling pathways. Chiisanoside might therefore be a potential ingredient for drug and food development against acute liver injury in the future. © 2018 Society of Chemical Industry.

Dauricine upregulates the chemosensitivity of hepatocellular carcinoma cells: Role of repressing glycolysis via miR-199a:HK2/PKM2 modulation

Dauricine (Dau) is a natural alkaloid exhibiting anti-proliferative activity against several different types of malignant cell. However, effects of Dau on hepatocellular carcinoma (HCC) cells and the underlying molecular mechanisms have remained to be fully elucidated. In this study, we found that Dau elevated the sensitivities of HCC cells to chemotherapeutic reagents, including cisplatin, sorafenib, and isoliensinine. Moreover, Dau promoted apoptosis of HCC cells triggered by these chemotherapeutic reagents. Consistently, in a xenograft mouse model, Dau sensitized HCC cells to sorafenib. In HCC cells, Dau dose-dependently inhibited glucose glycolysis and increased oxidative phosphorylation. Mechanistically, Dau downregulated the expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). HK2 and PKM2 can be directly targeted by miR-199a. Dau dose-dependently increased miR-199a expression in HCC cells. Transfection of anti-miR-199a abrogated Dau-mediated suppression of HK2 and PKM2. Dau-induced metabolic shift was thereby severely crippled by anti-miR-199a. In addition, the incremental activity of Dau on sorafenib sensitivity of HCC cells was diminished in response to the transfection of anti-miR-199a. Taken together, our findings provided novel insights into the impact of Dau on HCC cells and supported considering Dau as an adjuvant reagent in the clinical treatment of HCC.

Hepatoprotective effect of α-mangostin against lipopolysaccharide/d-galactosamine-induced acute liver failure in mice

The purpose of this study was to investigate the hepatoprotective effect of α-mangostin (α-MG) on lipopolysaccharide/d-galactosamine (LPS/D-GalN)-induced acute liver failure and discover its potential mechanisms in mice. The results showed that α-MG could attenuate LPS/D-GalN-induced liver pathological injury, and decrease the hepatic malondialdehyde (MDA) level, serum alanine aminotransferase (ALT), aspartate transaminase (AST), tumor necrosis factor (TNF-α), interleukin-1β and 6 (IL-1β, IL-6) levels and recovery hepatic glutathione (GSH), superoxide dismutase (SOD), catalase (CAT) activities. The results also indicated that α-MG inhibited LPS/D-GalN-induced toll-like receptor 4 (TLR4) expression and NF-κB activation. In addition, α-MG up-regulated the expressions of Nrf2 and heme oxygenase-1 (HO-1). In conclusion, the results indicated that α-MG could protect against LPS/D-GalN-induced liver failure by activating Nrf2 to induce antioxidant defense and inhibiting TLR4 signaling pathway to induce anti-inflammatory effect.

Protostemonine attenuates alternatively activated macrophage and DRA-induced asthmatic inflammation

Asthma is one of the most common pulmonary diseases that threatens human life because of lack of effective medicines. Protostemonine (PSN), an active alkaloid extracted from the roots of Stemona sesslifolia, has anti-inflammatory effects on acute lung injury and acute liver failure. However, it has not been defined whether PSN alleviates asthmatic inflammation. Here, we reported that PSN inhibits pulmonary eosinophil infiltration, goblet cell hyperplasia, mucus secretion, IgE and Th2 cytokine (IL-4, IL-5, IL-13 and IL-33) production by using DRA (dust mites, ragweed and aspergillus)-induced murine asthma model. Moreover, PSN also attenuated the expression of Arginase-1 (Arg-1), Ym-1 and Fizz-1, markers of AAM (alternatively activated macrophage) polarization, in lung tissues. In addition, PSN attenuated IL-4-induced expression of Arg-1, Ym-1 and Fizz-1 in bone marrow derived macrophages (BMDMs). Treatment with PSN decreased IL-4-induced STAT6 phosphorylation, KLF4 and IRF4 expression in BMDMs. Collectively, our results indicated that PSN ameliorates AAM polarization and asthmatic inflammation and might be a potential agent for treating asthma.

Curcumin Attenuates on Carbon Tetrachloride-Induced Acute Liver Injury in Mice via Modulation of the Nrf2/HO-1 and TGF-β1/Smad3 Pathway

This study aimed to investigate the protective effect of curcumin against carbon tetrachloride (CCl₄)-induced acute liver injury in a mouse model, and to explain the underlying mechanism. Curcumin at doses of 50, 100 and 200 mg/kg/day were administered orally once daily for seven days prior to CCl₄ exposure. At 24 h, curcumin-attenuated CCl₄ induced elevated serum transaminase activities and histopathological damage in the mouse's liver. Curcumin pre-treatment at 50, 100 and 200 mg/kg significantly ameliorated CCl₄-induced oxidative stress, characterized by decreased malondialdehyde (MDA) formations, and increased superoxide dismutase (SOD), catalase (CAT) activities and glutathione (GSH) content, followed by a decrease in caspase-9 and -3 activities. Curcumin pre-treatment significantly decreased CCl₄-induced inflammation. Furthermore, curcumin pre-treatment significantly down-regulated the expression of TGF-β1 and Smad3 mRNAs (both p < 0.01), and up-regulated the expression of nuclear-factor erythroid 2-related factor 2 (Nrf2) and HO-1 mRNA (both p < 0.01) in the liver. Inhibition of HO-1 attenuated the protective effect of curcumin on CCl₄-induced acute liver injury. Given these outcomes, curcumin could protect against CCl₄-induced acute liver injury by inhibiting oxidative stress and inflammation, which may partly involve the activation of Nrf2/HO-1 and inhibition of TGF-β1/Smad3 pathways.

Isoliensinine induces dephosphorylation of NF-kB p65 subunit at Ser536 via a PP2A-dependent mechanism in hepatocellular carcinoma cells: roles of impairing PP2A/I2PP2A interaction

Our previous study discovered that isoliensinine (isolie) triggers hepatocellular carcinoma (HCC) cell apoptosis via inducing p65 dephosphorylation at Ser536 and inhibition of NF-κB. Here, we showed that isolie promoted p65/PP2A interaction in vitro and in vivo. Repression of PP2A activity or knockdown of the expression of PP2A-C (the catalytic subunit of PP2A) abrogated isolie-provoked p65 dephosphorylation. I2PP2A is an endogenous PP2A inhibitor. Isolie directly impaired PP2A/I2PP2A interaction. Knockdown of I2PP2A boosted p65/PP2A association and p65 dephosphorylation. Overexpression of I2PP2A restrained isolie-induced p65 dephosphorylation. Untransformed hepatocytes were insensitive to isolie-induced NF-κB inhibition and cell apoptosis. In these cells, basal levels of I2PP2A and p65 phosphorylation at Ser536 were lower than in HCC cells. These findings collectively indicated that isolie suppresses NF-κB in HCC cells through impairing PP2A/I2PP2A interaction and stimulating PP2A-dependent p65 dephosphorylation at Ser536.

Protostemonine effectively attenuates lipopolysaccharide-induced acute lung injury in mice

Protostemonine (PSN) is the main anti-inflammatory alkaloid extracted from the roots of Stemona sessilifolia (known as "Baibu" in traditional Chinese medicine). Here, we reported the inhibitory effects of PSN on lipopolysaccharide (LPS)-induced macrophage activation in vitro and LPS-induced acute lung injury in mice. Macrophage cell line RAW264.7 cells and mouse bone marrow-derived macrophages (BMDMs) were treated with PSN (1, 3, 10, 30 and 100 μmol/L) for 0.5 h and then challenged with LPS (0.1 μg/mL) for 24 h. Pretreatment with PSN significantly inhibited LPS-induced phosphorylation of MAPKs and AKT, iNOS expression and NO production in the macrophages. C57BL/6 mice were intratracheally injected with LPS (5 mg/kg) to induce acute lung injury (ALI). The mice were subsequently treated with PSN (10 mg/kg, ip) at 4 and 24 h after LPS challenge. PSN administration significantly attenuated LPS-induced inflammatory cell infiltration, reduced pro-inflammatory cytokine (TNF-α, IL-1β and IL-6) production and eliminated LPS-mediated lung edema. Furthermore, PSN administration significantly inhibited LPS-induced pulmonary MPO activity. Meanwhile, LPS-induced phosphorylation of p38 MAPK, iNOS expression and NO production in the lungs were also suppressed. The results demonstrate that PSN effectively attenuates LPS-induced inflammatory responses in vitro and in vivo; the beneficial effects are associated with the decreased phosphorylation of MAPK and AKT and the reduced expression of pro-inflammatory mediators, such as iNOS, NO and cytokines. These data suggest that PSN may be a potential therapeutic agent in the treatment of ALI.

Astragalin Reduces Hexokinase 2 through Increasing miR-125b to Inhibit the Proliferation of Hepatocellular Carcinoma Cells in Vitro and in Vivo

Astragalin (ASG) can be found in a variety of food components. ASG exhibits cytotoxic effects on several different types of malignant cells. However, its effects on hepatocellular carcinoma (HCC) cells and the underlying molecular mechanisms have remained to be fully elucidated. Here, we revealed that ASG remarkably suppressed the proliferation of HCC cells. In HCC cells, ASG inhibited glucose glycolysis and promoted oxidative phosphorylation, resulting in a surge of reactive oxygen species (ROS). Mechanistically, ASG suppressed the expression of hexokinase 2 (HK2). This event was indispensible for ASG-mediated metabolic reprogramming, ROS accumulation, and subsequent growth arrest. Our further investigations unveiled that ASG repressed HK2 expression via increasing miR-125b. In vivo experiments showed that gavage of ASG decreased the proliferation of Huh-7 HCC xenografts in nude mice and inhibited the growth of transplanted H22 HCC cells in Kunming mice. Declined HCC tumor growth in vivo was associated with boosted miR-125b and reduced expression of HK2 in tumor tissues. Collectively, our results demonstrated that ASG is able to suppress the proliferation of HCC cells both in vitro and in vivo. Inhibition of HK2 through upregulating miR-125b and subsequent metabolic reprogramming is implicated in the antiproliferative effects of ASG on HCC cells.