Protective effects of sea buckthorn polysaccharide extracts against LPS/d-GalN-induced acute liver failure in mice via suppressing TLR4-NF-κB signaling

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.

Peroxiredoxin I deficiency increases LPS‑induced lethal shock in mice

Peroxiredoxin I (Prx I) plays a role in regulating macrophage proinflammatory cytokine production and gene expression and participates in immune regulation. However, the possible protective role of Prx I in endotoxin‑induced lethal shock is poorly understood. In the present study, western blot analysis, ELISA and haematoxylin and eosin staining were performed to examine the protein expression of cytoines and analyses the levels of cytokines in the serum and tissue to evaluate the tissue damage. The present study revealed that lipopolysaccharide (LPS)‑induced lethality in Prx I‑/‑ mice was is accelerated via the observed decreased serum IL‑10 levels. Results also demonstrated rapid immune cell infiltration and oxidative stress in the Prx I‑/‑mice liver after LPS injections. These phenomena increased liver apoptosis through increasing cleaved caspase‑3 protein expression in Prx I‑/‑ mice after LPS injections, resulting in high lethality after LPS challenges. These findings provide a new insight for understanding the function of Prx I against endotoxin‑induced injury.

Seabuckthorn berry polysaccharide protects against carbon tetrachloride-induced hepatotoxicity in mice via anti-oxidative and anti-inflammatory activities

The berries of Seabuckthorn (Hippophae rhamnoides L.) are traditional medicinal foods that have been used by Tibetans and Mongolians for thousands of years. The polysaccharides are the main components of Seabuckthorn berries, possessing immune stimulating, anti-cancer and anti-fatigue activities. The present study focused on evaluating the protective effects and mechanisms of Seabuckthorn berry polysaccharide (SP) against carbon tetrachloride (CCl₄)-induced hepatotoxicity. Mice were orally administrated with 50, 100 and 200 mg kg^-1 of SP once daily for 14 consecutive days prior to CCl₄ challenge. Pretreatment with SP significantly decreased alanine transaminase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBIL) levels, while increasing the levels of prealbumin (PALB) in the CCl₄-challenged mice, which were accompanied by diminished liver injuries, increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, increased GSH levels, and reduced malondialdehyde (MDA) content. The pretreatment with SP also markedly reduced the CCl₄-induced expression of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), inducible nitric oxide synthase (iNOS) and nitric oxide (NO). Furthermore, the pretreatment with SP decreased hepatic Toll-like receptor 4 (TLR4) expression and inhibited the phosphorylation of p38 MAPK, extracellular signal-regulated kinase (p-ERK), c-Jun N-terminal kinase (p-JNK) and nuclear factor-kappa B (NF-κB) in the CCl₄-challenged mice. These results suggest that the pretreatment with SP protected against CCl₄-induced liver damage via its anti-oxidative and anti-inflammatory activities. SP might be suitable for functional foods and natural drugs in preventing CCl₄-induced hepatotoxicity.

Seabuckthorn berry polysaccharide extracts protect against acetaminophen induced hepatotoxicity in mice via activating the Nrf-2/HO-1-SOD-2 signaling pathway

BACKGROUND

Oxidative stress is concomitant with acetaminophen (APAP)-induced hepatotoxicity, which has been highlighted as therapeutic targets for such diseases. The berries of Seabuckthorn (Hippophae rhamnoides L.) have been traditionally used in Tibetan medicine for thousands of years. The effect of Seabuckthorn berry polysaccharide on drug- induced liver injury (DILI) has not yet been elucidated.

PURPOSE

This study aims to investigate the protective effects and mechanisms of Seabuckthorn polysaccharide (SP) against APAP-induced hepatotoxicity.

STUDY DESIGN

Sixty C57BL/6 mice were randomly divided into six groups (n = 10 per group), namely the control group (Ctrl), APAP-induced-liver injury group (APAP), NAC pretreated group (NAC), 100 mg/kg SP pretreated group (APAP/SP100), 200 mg/kg SP pretreated group (APAP/SP200) and 200 mg/kg SP pretreated group without APAP challenge (SP200). SP was given orally to mice for 30 consecutive days prior to APAP exposure (300 mg/kg). NAC (150 mg/kg) was administrated 1 h before APAP challenge.

METHODS

ALT and AST were detected 16 h after APAP treatment; Hepatic expression of GSH, SOD, NO, iNOS and GSH-Px were examined. The expression of p-JNK, Bcl-2/Bax, p62, Keap-1 and SOD-2 was detected by Western blotting. The expression of Nrf-2 and its target genes HO-1, GCLC and NQO-1 were analyzed by RT-PCR and Western blotting.

RESULTS

Pretreatment with SP led to decreased levels of ALT and AST in APAP mice, without affecting APAP metabolism. This was accompanied by diminished liver injuries, increased levels of GSH and GSH-Px, reduced NO and iNOS expression. SP increased the activity of SOD as well as SOD-2 expression in APAP mice. SP suppressed APAP-induced JNK phosphorylation and increased the ratio of Bcl-2/Bax. Furthermore, SP decreased the expression of Keap-1 and increased the nuclear expression of Nrf-2. The expression of Nrf-2 target gene HO-1 was increased by SP pretreatment in APAP mice.

CONCLUSION

SP alleviates APAP-induced hepatotoxicity. The protective effects of SP are associated with the activation of the Nrf-2/HO-1-SOD-2 signaling pathway.

Macrophage immunomodulatory activity of the polysaccharide isolated from Collybia radicata mushroom

Polysaccharides from Collybia radicata mushroom (CRP) possess many functions, such as antiviral, anti-aging and hypolipidemic activities. However, little is known about their immunomodulatory activity. To address this issue, we did a thorough research into their immune effects on murine macrophages. The results showed that the 14942Da polysaccharide not only obviously improved the proliferation and phagocytosis of macrophages, but also induced the secretion of nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin factors (IL-1β, IL-6 and IL-10). At a concentration of 850.0μgmL^-1, the polysaccharide stimulated their proliferation and phagocytosis to 2.1 and 3.4 times, respectively, as compared to the negative group. Meanwhile, it raised the production of NO by inducing iNOS in a concentration-dependent manner. Furthermore, it enhanced the release of these cytokines to multiples from 2.3 to 3.6 times. As an inhibitor of TLR4 (Toll-like Receptor 4), TAK242 suppressed the secretion of NO, iNOS and cytokines above 51%, and ORP acted on the cells mainly via TLR4. Consequently, the polysaccharide has a potent immunomodulatory activity by stimulating macrophages and can be considered as a novel potential immunopotentiator in medical and food industries.

Protective effects of oxymatrine against lipopolysaccharide/D‑galactosamine‑induced acute liver failure through oxidative damage, via activation of Nrf2/HO‑1 and modulation of inflammatory TLR4‑signaling pathways

Oxymatrine has a variety of pharmacological functions, including anti-viral, anti-liver fibrotic, anti-cancer, anti‑bacterial, anti‑epidemic, analgesic, anti‑allergy and anti‑inflammatory properties. The present study aimed to investigate the protective effects of oxymatrine against lipopolysaccharide (LPS)/D‑galactosamine (D‑GalN)‑induced acute liver failure and the associated underlying mechanisms. Mice were administrated 4 mg/kg LPS and 600 mg/kg D‑GalN. Then, mice in the Oxymatrine group were treated with 120 mg/kg of oxymatrine for 4 weeks. Oxymatrine treatment increased survival rate, decreased plasma aspartate transaminase and alanine aminotransferase activity, increased superoxide dismutase and glutathione peroxidase and decreased malondialdehyde, tumor necrosis factor‑ and myeloperoxidase activities in mice with LPS/D‑GalN‑induced liver failure. Furthermore, Oxymatrine activated nuclear factor erythroid 2‑related factor (Nrf) 2 and heme oxygenase (HO)‑1 protein expression, and suppressed Toll like receptor (TLR)4, myeloid differentiation primary response 88 and nuclear factor‑κB protein expression in mice LPS/D‑GalN mice. Overall, the present study suggests that oxymatrine effectively attenuates LPS/D‑GalN‑induced acute liver failure by oxidative damage via activation of Nrf2/HO‑1 and modulation of TLR4‑dependent inflammatory signaling pathways.

Histone deacetylase 6 inhibitor ACY-1215 protects against experimental acute liver failure by regulating the TLR4-MAPK/NF-κB pathway

Histone deacetylase 6 (HDAC6) is considered a new target for anticancer, anti-inflammatory, and neurodegenerative treatment. ACY-1215 is a selective histone deacetylase 6 inhibitor, and it has been recognized as a potential anticancer and anti-inflammation drug. The aim of our study was to investigate whether ACY-1215 has protective effects on acute liver failure (ALF) in mice and explore its potential mechanism. Male C57/BL6 mice were divided into normal, model, and ACY-1215 groups. ACY-1215 (25mg/kg) and same amounts of saline were given to mice. After 2h, the ALF models were induced by lipopolysaccharide (LPS, 100μg/kg) combined with D-galactosamine (D-gal, 400mg/kg). All animals were killed after 24h. The expressions of HDAC6 were determined by western blotting and RT-PCR assay. The expression levels of inflammatory cytokines were detected by ELISA and RT-PCR. The protein expression of Toll-like receptor 4 (TLR4), mitogen-activated protein kinase (MAPK), and nuclear factor κB (NF-κB) species were determined by western blot. The mortality of mice with ALF induced by LPS and D-gal was significantly decreased by ACY-1215 pretreatment. Procedures to manage ALF caused adversely affected liver histology and function; this damage was repaired by pretreatment of ACY-1215. ACY-1215 treatment also attenuated the serum and messenger RNA levels of the proinflammatory cytokines. Pretreatment of ACY-1215 significantly decreased the protein expression of TLR4 and the activation of MAPK and NF-κB signalling pathways. ACY-1215 has potential therapeutic value in mice with ALF by directly inhibiting inflammatory response via regulation of the TLR4-MAPK/NF-kB pathway.

Hepatoprotective effect of quercetin against LPS/d-GalN induced acute liver injury in mice by inhibiting the IKK/NF-κB and MAPK signal pathways

Quercetin is regarded as a potential hepatoprotective agent in the treatment of acute liver injury. However, the underlying mechanism of how quercetin to protect against lipopolysaccharides/d-galactosamine (LPS/d-GalN) induced acute liver injury remains unclear. To investigate the mechanism, the antioxidative, anti-inflammatory and antiapoptotic responses were performed. The results showed that quercetin pretreatment improved the survival rate and substantially reduced the liver histopathological changes in mice. It also alleviated the hepatic damage and reduced the productions of oxidative markers induced by LPS/d-GalN. In addition, quercetin pretreatment significantly diminished the production of inflammatory cytokines, including TNF-α, IL-6 and IL-1β, and inhibited the activation of the NF-κB and MAPK signaling pathways as well as the expression of apoptotic-related proteins induced by LPS/d-GalN. We found that the potential mechanism of this quercetin-induced protection is mainly mediated through its powerful antioxidative capacity, inhibition of hepatocyte apoptosis and suppression of inflammatory cytokines through the IKK/NF-κB and MAPK signaling pathways. Thus, quercetin shows a promising therapeutic effect on acute liver injury in mice.

Gubenyiliu II Inhibits Breast Tumor Growth and Metastasis Associated with Decreased Heparanase Expression and Phosphorylation of ERK and AKT Pathways

Gubenyiliu II (GYII), a Traditional Chinese Medicine (TCM) formula used in our hospital, has shown beneficial effects in cancer patients. In this study, we investigated the molecular mechanisms underlying the beneficial effects of GYII on murine breast cancer models. GYII showed significant inhibitory effects on tumor growth and metastasis in the murine breast cancer model. Additionally, GYII suppressed the proliferation of 4T1 and MCF-7 cells in a dose-dependent manner. A better inhibitory effect on 4T1 cell proliferation and migration was found in the decomposed recipes (DR) of GYII. Moreover, heparanase expression and the degree of angiogenesis were reduced in tumor tissues. Western blot analysis showed decreased expression of heparanase and growth factors in the cells treated with GYII and its decomposed recipes (DR2 and DR3), and thereby a reduction in the phosphorylation of extracellular signal-regulated kinase (ERK) and serine-threonine kinase (AKT). These results suggest that GYII exerts anti-tumor growth and anti-metastatic effects in the murine breast cancer model. The anti-tumor activity of GYII and its decomposed recipes is, at least partly, associated with decreased heparanase and growth factor expression, which subsequently suppressed the activation of the ERK and AKT pathways.

Establishment of a new acute-on-chronic liver failure model

To establish an animal model of acute-on-chronic liver failure (ACLF) that would replicate the pathological process of ACLF in humans, rats were administered porcine serum (PS) for 11 weeks. Liver fibrosis was determined by pathological and biochemical assessments. The animals then were injected with d-galactosamine (d-gal) and lipopolysaccharide (LPS). The survival times of animals with cirrhosis and ACLF were determined over 48 h. Other animals were killed at 0, 4, 8 and 12 h after administration of d-gal/LPS. Liver injury was assessed by histopathological analysis and biochemical indices, and apoptosis was detected by Western blot and TUNEL analysis. After PS administration for 11 weeks the serum levels of hyaluronic acid and N-procollagen type III peptide increased significantly, and serious fibrosis and cirrhosis was observed at weeks 10 and 11. Cirrhotic rats were injected with d-gal/LPS to induced ACLF; the rate of mortality over 48 h was 80%. ALT and AST levels increased markedly at 4 h, but decreased significantly at 8 and 12 h post-treatment. The total bilirubin, direct bilirubin, and total bile acids levels increased markedly at 8 and 12 h. Clotting times, TNF-α and IL-6 levels increased significantly, except for 12 h post-treatment. Apoptosis, inflammation and necrosis were elevated as determined by hematoxylin-eosin staining and TUNEL assays. BCL-2 levels decreased significantly, While BAX levels increased significantly. Cytochrome c expression peaked at 8 h post-d-gal/LPS treatment. In conclusion, an ACLF model induced by PS and d-gal/LPS was established and the underlying mechanisms of ACLF development were explored.

Sulfated Cyclocarya paliurus polysaccharides markedly attenuates inflammation and oxidative damage in lipopolysaccharide-treated macrophage cells and mice

Natural polysaccharides and their modified derivatives are crucial supplements to the prevention of inflammation. This study aimed to evaluate the effect of sulfated modification on the anti-inflammatory and anti-oxidative activities of Cyclocarya paliurus polysaccharides (CP). A sulfated CP, S-CP1-4 was obtained using chlorosulfonic acid-pyridine method. The chemical components and FT-IR spectrum confirmed that sulfated group was synthesized to the polysaccharide chains successfully. S-CP1-4 was found to inhibit nitric oxide production, phagocytic activity and the release of interleukin (IL)-6 and IL-1β in lipopolysaccharide-treated macrophage cells, RAW 264.7. S-CP1-4 significantly decreased the secretion of IL-6 and TNF-α and the thymus and spleen indexes, and increased the production of IL-10 in lipopolysaccharide-treated mice. S-CP1-4 could better protect the liver by inhibiting the activities of alanine aminotransferase and aspartate aminotransferase, and malondialdehyde level while increasing the superoxide dismutase activity and total anti-oxidative capacity. These results suggested that S-CP1-4 may be an effective anti-inflammatory agent, and sulfated modification may be a reliable method for the development of food supplements.

Radix isatidis Polysaccharides Inhibit Influenza a Virus and Influenza A Virus-Induced Inflammation via Suppression of Host TLR3 Signaling In Vitro

Influenza remains one of the major epidemic diseases worldwide, and rapid virus replication and collateral lung tissue damage caused by excessive pro-inflammatory host immune cell responses lead to high mortality rates. Thus, novel therapeutic agents that control influenza A virus (IAV) propagation and attenuate excessive pro-inflammatory responses are needed. Polysaccharide extract from Radix isatidis, a traditional Chinese herbal medicine, exerted potent anti-IAV activity against human seasonal influenza viruses (H1N1 and H3N2) and avian influenza viruses (H6N2 and H9N2) in vitro. The polysaccharides also significantly reduced the expression of pro-inflammatory cytokines (IL-6) and chemokines (IP-10, MIG, and CCL-5) stimulated by A/PR/8/34 (H1N1) at a range of doses (7.5 mg/mL, 15 mg/mL, and 30 mg/mL); however, they were only effective against progeny virus at a high dose. Similar activity was detected against inflammation induced by avian influenza virus H9N2. The polysaccharides strongly inhibited the protein expression of TLR-3 induced by PR8, suggesting that they impair the upregulation of pro-inflammatory factors induced by IAV by inhibiting activation of the TLR-3 signaling pathway. The polysaccharide extract from Radix isatidis root therefore has the potential to be used as an adjunct to antiviral therapy for the treatment of IAV infection.

Radix isatidis Polysaccharides Inhibit Influenza a Virus and Influenza A Virus-Induced Inflammation via Suppression of Host TLR3 Signaling In Vitro

Influenza remains one of the major epidemic diseases worldwide, and rapid virus replication and collateral lung tissue damage caused by excessive pro-inflammatory host immune cell responses lead to high mortality rates. Thus, novel therapeutic agents that control influenza A virus (IAV) propagation and attenuate excessive pro-inflammatory responses are needed. Polysaccharide extract from Radix isatidis, a traditional Chinese herbal medicine, exerted potent anti-IAV activity against human seasonal influenza viruses (H1N1 and H3N2) and avian influenza viruses (H6N2 and H9N2) in vitro. The polysaccharides also significantly reduced the expression of pro-inflammatory cytokines (IL-6) and chemokines (IP-10, MIG, and CCL-5) stimulated by A/PR/8/34 (H1N1) at a range of doses (7.5 mg/mL, 15 mg/mL, and 30 mg/mL); however, they were only effective against progeny virus at a high dose. Similar activity was detected against inflammation induced by avian influenza virus H9N2. The polysaccharides strongly inhibited the protein expression of TLR-3 induced by PR8, suggesting that they impair the upregulation of pro-inflammatory factors induced by IAV by inhibiting activation of the TLR-3 signaling pathway. The polysaccharide extract from Radix isatidis root therefore has the potential to be used as an adjunct to antiviral therapy for the treatment of IAV infection.

ANTI-INFLAMMATORY ACTIVITY OF PLATYCODIN D ON ALCOHOL-INDUCED FATTY LIVER RATS VIA TLR4-MYD88-NF-κB SIGNAL PATH

BACKGROUND

The current study was designed to evaluate the effect of Platycodin D (PD), triterpenoid saponins extracted from the roots of Platycodon grandiflorum (PG) on alcohol-induced fatty liver (AFL) and investigate the possible mechanism.

METHODS AND MATERIALS

A rat model was set up by feeding ethanol and fish oil to experimental rats, which then were treated with PD of 10, 20, 30 mg/kg body weight/day for 4 weeks, respectively, whereafter, liver function enzymes, endotoxin of serum and liver lipid were assayed by biochemical methods, cytokines, histochemistry of hepatic tissue, the protein expression of CD14 and TLR4, the mRNA expression of MD-2, MyD 88 and TRAF-6 were assayed.

RESULTS

Treatment with PD on AFL rats significantly decreased the levels of serum ALT, AST and TBIL, coefficient of liver index and the hepatic tissue contents of TG, additionally and dramatically decreased serum endotoxin levels, down-regulated MD-2 and CD14 levels, as well as the mRNA expression of TLR4, MyD88 and TRAF-6, accordingly suppressed NF-κB: p65 as well as endotoxin-mediated inflammatory factors such as TNF-α and IL-6.

CONCLUSIONS

Treatment with PD effectively protects against AFL through anti-inflammatory and anti-endotoxic process, and the confirmed mechanism is that PD treatment ameliorate alcoholic-induced liver injury mainly via TLR4-MyD88-NF-K: B signal path in AFL rat. List of Abbreviations: AFL: alcoholic-induced fatty liver, CD14: cluster of differentiation 14, LPS: lipopolysaccharide, LBP: lipopolysaccharide-binding protein, TLR4: toll-like receptor 4, MD-2: molecule myeloid differential protein-2, MyD 88: myeloid differentiation primary response protein 88, TRAF-6: TNF-receptor associated factor-6, NF-κB: nuclear transcription factor kappa B, IL-6: interleukin-6, TNF-α: tumor necrosis factor-α, PG: Platycodon grandiflorum, PD: Platycodin D.