Supercritical extract of Seabuckthorn Leaves (SCE200ET) inhibited endotoxemia by reducing inflammatory cytokines and nitric oxide synthase 2 expression

IDENTIFYING POTENTIAL KEY FERROPTOSIS-RELATED GENES AND THERAPEUTIC DRUGS IN SEPSIS-INDUCED ARDS BY BIOINFORMATICS AND EXPERIMENTAL VERIFICATION

ABSTRACT

Background: Acute respiratory distress syndrome (ARDS) is a serious pathological process with high mortality. Ferroptosis is pivotal in sepsis, whose regulatory mechanisms in sepsis-induced ARDS remains unknown. We aimed to determine key ferroptosis-related genes in septic ARDS and investigate therapeutic traditional Chinese medicine. Method: Sepsis-induced ARDS dataset obtained from Gene Expression Omnibus was analyzed to identify ferroptosis-related differentially expressed genes. Enrichment analysis and protein-protein interaction network construction were performed to identify hub genes. Immune cells infiltration was analyzed and competitive endogenous RNA network was constructed. The diagnostic value of hub genes in septic ARDS was analyzed and the occurrence of ferroptosis and the expression of hub genes were detected. Traditional Chinese medicine targeting hub genes was predicted via SymMap database and was verified. Results: Sixteen ferroptosis-related differentially expressed genes were obtained, among which the top four genes ( IL1B , TXN , MAPK3 , HSPB1 ) were selected as hub genes, which may be potential diagnostic markers of septic ARDS. Immunoassay showed that sepsis-induced ARDS and hub genes were closely related to immune cells. The competitive endogenous RNA network showed 26 microRNAs and 38 long noncoding RNA. Ferroptosis occurred and the expressions of IL1B , MAPK3 , and TXN were increased in septic ARDS mice and LPS-challenged human pulmonary alveolar epithelial cells. Sea buckthorn alleviated septic lung injury and affected hub genes expression. Conclusions: Ferroptosis-related genes of IL1B , MAPK 3, and TXN serve as potential diagnostic genes for sepsis-induced ARDS. Sea buckthorn may be therapeutic medication for ARDS. This study provides a new direction for septic ARDS treatment.

Optimization of polyphenol extraction from Hippophae salicifolia D. Don leaf using supercritical CO2 by response surface methodology

In this study, an eco-friendly supercritical carbon dioxide (SC-CO2) extraction of polyphenolic compounds from Hippophae salicifolia leaf was optimized to achieve the highest extraction yield with maximum total phenolic content (TPC) and minimum IC50. The central composite design was used to establish an experimental design for RSM. The effect of the pressure, temperature, carbon dioxide flow rate, and co-solvent amount was scrutinized using variance analysis (ANOVA). Under optimized condition (25.13 MPa, 47.53 °C, 14.47 g/min, and 2.43%), the experimental data (yield of extraction: 4.38%, TPC: 84.31 mg GAE/g, and IC50: 41.94 µg/mL) showed good agreement with the predicted values (yield of extraction: 4.53%, TPC: 83.37 mg GAE/g, and IC50: 40.2 µg/mL). Nine polyphenolic compounds: gallic acid, caffeic acid, ferulic acid, vanillic acid, p-coumaric acid, quercetin, myricetin, kaempferol, and rutin were analyzed in SC-CO2 extract using HPLC. SC-CO2 extraction was more selective for ferulic acid, myricetin, and quercetin extraction. The study results revealed that SC-CO2 extract had significant antibacterial activity against eight bacterial strains.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03358-1.

Hippophae rhamnoides L. leaf and twig extracts as rich sources of nutrients and bioactive compounds with antioxidant activity

Plants have served for centuries as sources of compounds useful for human health such as antioxidant, anti-diabetic and antitumor agents. They are also rich in nutrients that improve the human diet. Growing demands for these compounds make it important to seek new sources for them. Hippophae rhamnoides L. is known as a plant with health-promoting properties. In this study we investigated the chemical composition and biological properties of bioactive components of ethanol extracts from leaves and twigs of H. rhamnoides L. Chemical components such as the total content of phenolic compounds, vitamins and amino acids and the antioxidant activities of these compounds in cellular and cell-free systems were assessed. The results suggest that the studied extracts are rich in bioactive compounds with potent antioxidant properties. Cytotoxicity and hemotoxicity assays showed that the extracts had low toxicity on human cells over the range of concentrations tested. Interaction with human serum albumin was investigated and conformational changes were observed. Our results indicate that leaf and twig extracts of H. rhamnoides L. should be considered as a non-toxic source of bioactive compounds which may be of interest to the food, pharmaceutical and cosmetic industries.

Troxerutin attenuates inflammatory response in lipopolysaccharide-induced sepsis in mice

Troxerutin (Tx), known as vitamin P₄ is a derivative of natural bioflavonoid rutin. Tx possesses different biological activities such as antioxidant, anticancer, and anti-inflammatory. The current study was conducted to determine potential therapeutic effect of Tx in lipopolysaccharides (LPS)-induced sepsis in mice. In LPS-induced sepsis, the mice were treated intraperitoneally (ip) with Tx twice daily. Therapeutic effect was assessed by measuring serum level of cytokines, alanine aminotransferase (ALT) and lactate dehydrogenase (LDH). Level of nitric oxide (NO), superoxide dismutase (SOD), catalase (CAT), Myeloperoxidase (MPO) and Malondialdehyde (MDA) was measured. Expression of CD40 receptor on leucocytes was measured using flowcytometry. Splenocyte proliferation was evaluated using MTT assay. The effect of Tx on survival rate during administration of lethal dose of LPS was investigated. The results showed that Tx inhibited LPS induced NO production. Inflammatory pathways were suppressed by reduction of inflammatory cytokines production. Further, elevated CD40 expression of leucocytes and proliferation of splenocytes markedly reduced in Tx treated group. Antioxidant defense system was enhanced by increased activity of SOD and CAT and decreased level of MDA. MPO, ALT and LDH activity. Additionally, treatment with Tx significantly increased the mean survival time of mice compared with the LPS treated group. Histologically, Tx treatment decreased inflammatory cells infiltration and histopathologicl changes in the liver. Our findings showed that reduced inflammatory parameters, improved antioxidant activity, reduced histological lesions and increased survival rate. These findings suggest that Tx is an effective anti-inflammatory agent for the treatment of LPS-induced sepsis.

Compressed fluids and phytochemical profiling tools to obtain and characterize antiviral and anti-inflammatory compounds from natural sources

Many natural compounds, found mainly in plants, are associated with the treatment of various diseases. The search for natural therapeutic agents includes compounds with antiviral and anti-inflammatory activities. Among the many steps involved in bioprospection, extraction is the first and most critical step for obtaining bioactive compounds. One of the main advantages of using compressed fluids extraction is the high quality of the final product obtained due to the use of green solvents, while the selectivity towards target compounds can be tuned by adjusting the process parameters, especially pressure, temperature and solvent characteristics. In this review, a discussion is provided on the power of compressed fluids, such as supercritical fluid extraction (SFE), pressurized liquid extraction (PLE) and subcritical water extraction (SWE) to obtain antiviral and anti-inflammatory compounds from natural sources. In addition, an adequate knowledge about the identity and quantity of the compounds present in the extract is essential to correlate biological activity with chemical composition. Phytochemical profiling tools used for identification and quantification of these bioactive natural compound are also discussed. It can be anticipated that after the current SARS-COV-2 pandemic, the search of new natural compounds with antiviral and anti-inflammatory activity will be a hot research topic, so, this review provides an overview on the technologies currently used that could help this research.

The bioactive components as well as the nutritional and health effects of sea buckthorn

Sea buckthorn (SB), also named sea berry, Hippophae rhamnoides L. or Elaeagnus rhamnoides L., has been used in daily life for centuries with kinds of purposes ranging from a beverage with a pleasant taste and flavor, to an agent for treatment of many disorders and diseases. SB is well known more than just a fruit. So far, a unique mixture of bioactive components was elucidated in SB including flavonoids, phenolic acids, proanthocyanidins, carotenoids, fatty acids, triterpenoids, vitamins and phytosterols, which implied the great medicinal worth of this seaberry. Both in vitro and in vivo experiments, ranged from cell lines to animals as well as a few in patients and healthy volunteers, indicated that SB possessed various biological activities including anti-inflammatory and immunomodulatory effects, antioxidant properties, anti-cancer activities, hepato-protection, cardiovascular-protection, neuroprotection, radioprotection, skin protection effect as well as the protective effect against some eye and gastrointestinal sickness. Furthermore, the toxicological results revealed neither the fruits, nor the seeds of SB were toxic. The present review summarizes the unique profile of the chemical compounds, the nutritional and health effects as well as the toxicological properties of SB, which lay the foundation for practical applications of SB in treatment of human diseases.

Sea buckthorn (SB), also named sea berry, has been used in daily life for centuries with kinds of purposes ranging from a beverage with a pleasant taste and flavor, to an agent for treatment of many disorders and diseases.

Hippophae rhamnoides polysaccharides protect IPEC-J2 cells from LPS-induced inflammation, apoptosis and barrier dysfunction in vitro via inhibiting TLR4/NF-κB signaling pathway

Inflammatory response caused by early weaning stress in piglets is associated with various diseases. The Hippophae rhamnoides polysaccharide (HRP) exhibits anti-inflammatory activity and immunomodulatory properties. The mechanisms for the protective effects of HRP on barrier function, inflammatory damage and apoptosis in intestinal porcine epithelial cells (IPEC-J2) induced by the lipopolysaccharide (LPS) are unknown. In this study, we first demonstrated the cytotoxicity of HRP-induced IPEC-J2 cells by reducing cell viability. IPEC-J2 cells were treated with 0-800 μg/mL doses of HRP, and 0-600 μg/mL doses were used in further experiments. Upon exposure to LPS, the viability of IPEC-J2 cells, ROS production, immunoglobulin levels (immunoglobulin M (IgM), immunoglobulin A (IgA) and immunoglobulin G (IgG)) and tight junction protein level (zonula occludens-1 (ZO-1), occluding, claudin-1) decreased. Inflammatory factors (interleukin-1beta (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-α)) and apoptosis (Bcl-2, Bax, caspase-3, caspase-8 and caspase-9) were increased. Cell morphology and internal structure were damaged in the LPS treatment. Pre-treating cells with HRP (0-600 μg/mL) reduced inflammatory factors levels, apoptosis rate, increased immunoglobulins, tight junction protein levels and relieved cell surface morphology damage. Pre-treatment with HRP also reduced the levels of the Toll-like receptor 4 (TLR4) and Myeloid differentiation factor 88 (MyD88) and inhibited the phosphorylated NF-κB factor-kappa B (NF-κB) in cells induced by LPS. These results show that pre-treatment with HRP protected against LPS-induced IPEC-J2 cell damage through its anti-inflammatory activity.

Cytokines Driven Anti-Inflammatory and Anti-Psoriasis Like Efficacies of Nutraceutical Sea Buckthorn (Hippophae rhamnoides) Oil

Psoriasis is a chronic inflammatory skin disease characterized by circumscribed, red, thickened plaques with overlying silvery white scales. It is associated with the release of pro-inflammatory mediators that lead to the development of edema and distress. Here we show the anti-inflammatory and anti-psoriatic efficacies of a neutraceutical sea buckthorn oil (SBKT) derived from the fruit pulp of Hippophae rhamnoides. Chemical analysis of the SBKT showed the presence of 16 major saturated, mono-, and polyunsaturated fatty acids components, imparting significant nutritional values. Efficacy of the SBKT in modulating psoriasis and associated inflammation was first tested in vitro using human monocytic (THP-1) cells. SBKT induced cytotoxicity at a dose of ≥25 µl/ml. Treatment of the lipopolysaccharide-stimulated THP-1 cells with SBKT subdued the enhanced release of intracellular reactive nitrogen species and expression of NF-κB protein, in a concentration-dependent manner. This was accompanied by a reduction in the release of downstream pro-inflammatory cytokines: Interleukin-1ß and interleukin-6. Tumor necrosis factor-α released in the stimulated THP-1 cells were also inhibited by SBKT dose of 5 µl/ml. In vivo oral and topical treatment with SBKT in the Carrageenan-stimulated paw edema model, showed a significant decrease in paw volume and edema. In the 12-O tetradecanoyl phorbol 13-acetate (TPA) stimulated CD-1 mice psoriasis-like model, concurrent oral and tropical SBKT treatments substantially reduced ear edema and ear biopsy weights. Histopathologically, significant reduction in ear epidermal thickness and skin lesion scores was observed in the SBKT-treated animals. In conclusion, SBKT showed anti-inflammatory and anti-psoriasis-like efficacies in healing chemical-induced inflammation and psoriasis. The possible mode of action of SBKT was found through inhibition of reactive nitrogen species, and downregulation of NF-κB protein and pro-inflammatory cytokines. Thus, the present data suggest that Sea buckthorn oil can be used as an anti-inflammatory and anti-psoriatic nutraceutical.

A novel in vivo adjuvant activity of kaempferol: enhanced Tbx-21, GATA-3 expression and peritoneal CD11c+MHCII+ dendritic cell infiltration

OBJECTIVE

Kaempferol, a natural flavonol present in various traditional medicinal plants, is known to possess potent anti-inflammatory properties. This study was designed to study the adjuvant effect of kaempferol administration along with ovalbumin antigen (K + O) in balb/c mice.

METHODS

Mice were immunized with kaempferol (100 and 50 mg/kg body weight) without or with ovalbumin (20 µg/mouse). After priming, booster was administered on day 21. Antigen specific IgG titers and its subtypes, on day 28, were estimated by indirect ELISA. Effect of kaempferol administration on CD11c⁺MHCII⁺ peritoneal dendritic cells was studied by flow cytometry. Expression levels of proteins Tbx21, GATA-3, BLIMP-1, Caspase-1 and Oct-2 were studied by western blotting. LPS activated IL-1β production by peritoneal cells of immunized mice was estimated by sandwich ELISA.

RESULTS

Ovalbumin specific IgG, IgG1 and IgG2a antibody titers in sera samples of K + O immunized mice increased significantly (p < .01) as compared to controls. The enhanced Th1 and Th2 immune response in K + O immunized mice was also supported by the increased expression of Tbx21 and GATA-3 transcription factors in splenocytes. This corroborated with increased BLIMP-1 and Oct-2 protein expression. Kaempferol increased the infiltration of peritoneal CD11c⁺MHCII⁺ dendritic cells but failed to enhance LPS activated IL-1β by peritoneal macrophages and suppressed caspase-1 protein expression as compared to that in ovalbumin immunized mice.

CONCLUSION

Present study strongly demonstrates the novel adjuvant activity of kaempferol in vivo and its potential as an immunostimulatory agent.

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.

Oxidative stress and cellular pathways of asthma and inflammation: Therapeutic strategies and pharmacological targets

Asthma is a complex inflammatory disease characterized by airway inflammation and hyperresponsiveness. The mechanisms associated with the development and progression of asthma have been widely studied in multiple populations and animal models, and these have revealed involvement of various cell types and activation of intracellular signaling pathways that result in activation of inflammatory genes. Significant contributions of Toll-like-receptors (TLRs) and transcription factors such as NF-кB, have been reported as major contributors to inflammatory pathways. These have also recently been associated with mechanisms of oxidative biology. This is of important clinical significance as the observed inefficacy of current available treatments for severe asthma is widely attributed to oxidative stress. Therefore, targeting oxidizing molecules in conjunction with inflammatory mediators and transcription factors may present a novel therapeutic strategy for asthma. In this review, we summarize TLRs and NF-кB pathways in the context of exacerbation of asthma pathogenesis and oxidative biology, and we discuss the potential use of polyphenolic flavonoid compounds, known to target these pathways and possess antioxidant activity, as potential therapeutic agents for asthma.

Flavonoids from sea buckthorn inhibit the lipopolysaccharide-induced inflammatory response in RAW264.7 macrophages through the MAPK and NF-κB pathways

Sea buckthorn has long been used as a functional food to regulate cholesterol, relieve angina, and diminish inflammation. Flavonoids are one of the main active components in sea buckthorn. We investigated the effects of sea buckthorn flavonoid (SF) treatment on two pathways that mediate inflammation, the mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) pathways, to explore the anti-inflammatory activity of SFs in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. The LPS-induced over-production of nitric oxide (NO) and prostaglandin E2 (PGE₂) was inhibited by SFs through a mechanism related to the modulatory effects of the inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) genes. Additionally, SFs downregulated the production and mRNA expression of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β. Moreover, SFs inhibited the phosphorylation of the p38 and stress-activated protein kinase/jun amino-terminal kinase (SAPK/JNK) MAPK pathways, and they reduced the nuclear translocation of NF-κB to prevent its activation by blocking the phosphorylation and degradation of inhibitor protein of NF-κB α (IκB-α). Based on these findings, SFs may exert their inhibitory effects on inflammation by regulating the release of inflammatory mediators through the MAPK and NF-κB pathways. SFs highlight the potential benefits of using functional foods with anti-inflammatory actions to combat inflammatory diseases.

Anti-inflammatory activity of the functional groups present in Hippophae rhamnoides (Seabuckthorn) leaf extract

ETHNO PHARMACOLOGICAL RELEVANCE

The study explores the anti-inflammatory activity of components present in fractions obtained from leaves of Hippophae rhamnoides in mouse peritoneal macrophages.

AIM OF THE STUDY

Immunomodulators salvage the immune response by enhancing or reducing its capacity to the required level. Plant extracts are extensively used as immunomodulators because of their easy availability, simple methods of preparation and minimum side effects with maximum efficacy.

MATERIALS AND METHODS

The present study was conducted to assess the immunomodulatory activities of phyto constituents present in Seabuckthorn leaves. The aqueous-alcoholic leaf extract was subjected to successive and parallel extraction in the presence of polar and non-polar solvents for fractionation of compounds. Based on the yield, three fractions were selected viz. parallel methanol (PM), successive chloroform (SC) and successive methanol (SM) and screened for in vitro immunomodulatory activities. Peritoneal macrophages were isolated from Balb/c mice and cultured with or without LPS to evaluate the immunomodulatory effect of the three fractions on cell viability, hemolytic activity, nitric oxide (NO) production, cytokine levels, iNOS and COX-2 expressions.

RESULTS

The results revealed that none of the three fractions induced hemolysis. Cells treated with PM fraction significantly suppressed LPS-induced NO production and pro-inflammatory cytokines such as TNF-α, IL-6 and IFN-γ as compared to SC and SM treatment. The iNOS and COX-2 expressions were also significantly reduced after treatment with PM fraction.

CONCLUSIONS

The decrease in LPS-induced NO production, pro-inflammatory cytokine secretion, iNOS and COX-2 expression signifies anti-inflammatory properties of PM fraction containing tannins, proteins and carbohydrate groups. Hence, this plant-derived immunomodulator can be used as a therapeutic agent in inflammatory diseases.

Quercetin exhibits adjuvant activity by enhancing Th2 immune response in ovalbumin immunized mice

Quercetin, one of the most abundant of plant flavonoids, has been studied with a great deal of attention over the last several decades mainly for its properties in inflammation and allergy. In this study, we are reporting for the first time the in vivo immunostimulatory activity of quercetin in ovalbumin immunized Balb/c mice. Administration of quercetin (50mg/kg body weight) along with ovalbumin antigen showed increased ovalbumin specific serum IgG antibody titres in comparison to the control group (p<0.05). Quercetin administration not only showed predominance of Th2 immune response by increasing the IgG1 antibody titres, but also increased the infiltration of CD11c⁺ dendritic cells in the mouse peritoneum and also increased LPS activated IL-1β and nitric oxide (NO) production by peritoneal macrophages. Expression of Tbx21, GATA-3 and Oct-2 proteins also enhanced in splenocytes of quercetin administered mice. Quercetin also did not cause any hemolysis in human RBCs. Overall, our findings strongly demonstrate the novel in vivo immunostimulatory and adjuvant potentials of quercetin.

Augmentation of humoral and cellular immunity in response to Tetanus and Diphtheria toxoids by supercritical carbon dioxide extracts of Hippophae rhamnoides L. leaves

Hippophae rhamnoides L. commonly known as Seabuckthorn (SBT), a wild shrub of family Elaegnacea, has extensively used for treating various ailments like skin diseases, jaundice, asthma, lung troubles. SBT leaves have been reported to possess several pharmacological properties including immunomodulatory, antioxidant, anti-inflammatory, antimicrobial and tissue regeneration etc. The present study was undertaken to evaluate the adjuvant property of supercritical carbon dioxide extracts (SCEs 300ET and 350ET) of SBT leaves in balb/c mice immunized with Tetanus and Diphtheria toxoids. The dynamic changes in the immune response were measured in terms of humoral and cell-mediated immune responses. We have seen the effect of SCEs on immunoglobulin subtypes and secondary immune response generation. In addition, the effect of SCEs on antigen specific cellular immunity was evaluated. Our results show that SCEs 300ET and 350ET significantly enhanced antibody titers in response to both TT and DT antigens. The secondary immune response generated was significantly increased in case of TT immunized animals. SCEs also enhanced cytokine levels (IFN-γ, IL-4, TNF-α and IL-1β) and increased lymphoproliferation. Besides, both SCEs did not show any toxic effects. Therefore, the study suggests that SCEs are safe and have potent immunostimulatory activity and hence, seems to be a promising balanced Th1 and Th2 directing immunological adjuvant for various veterinary as well as human vaccines.

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

ETHNOPHARMACOLOGICAL RELEVANCE

Sea buckthorn (Hippophae rhamnoides L.) berries have been traditionally used to treat gastric disorders, cardiovascular problems, and liver injuries in oriental medicinal system. This study aimed to explore the protective effects and mechanisms of the polysaccharide extracts of Sea buckthorn (HRP) berries against lipopolysaccharide (LPS) and d-galactosamine hydrochloride (d-GalN)-induced acute liver failure in mice.

MATERIALS AND METHODS

HRP was isolated by hot-water extraction and characterized by HPLC and infrared spectrum analysis. The total carbohydrate, uronic acid and protein contents of HRP were measured by a spectrophotometric method. Mice were orally administrated with HRP (50, 100, 200mg/kg) once daily for 14 consecutive days prior to the challenge with LPS (50 μg/kg) and d-GalN (300 mg/kg). Animals of positive control group were intraperitoneally injected with dexamethasone (10mg/kg). Mice were sacrificed at 8h after LPS/d-GalN injection.

RESULTS

Pretreatment with HRP significantly inhibited LPS/d-GalN-induced increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, which were accompanied by alleviated liver injuries and reduced production of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). HRP was also found to reduce malondialdehyde (MDA) content and to restore superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities. Furthermore, HRP supplementation dose-dependently inhibited the expression of Toll-like receptor 4 (TLR4), phosphorylated extracellular signal-regulated kinase (p-ERK), phosphorylated c-Jun N-terminal kinase (p-JNK), and phosphorylated mitogen activated protein kinase 38 (p-p38 MAPK) in the liver of LPS/d-GalN challenged mice. Pretreatment with HRP also inhibited LPS/d-GalN-induced activation and translocation of nuclear factor-κB (NF-κB).

CONCLUSIONS

This study indicates that pretreatment with HRP protects against LPS/d-GalN-induced liver injury in mice via suppressing the TLR4-NF-κB signaling pathway. Sea buckthorn may be a hopeful drug for prevention of acute live injury.

A novel fibrinogenase from Agkistrodon acutus venom protects against LPS-induced endotoxemia via regulating NF-κB pathway

CONTEXT

Endotoxins including lipopolysaccharide (LPS) could cause endotoxemia which often results in excessive inflammation, organ dysfunction, sepsis, disseminated intravascular coagulation (DIC) or even death. Previously, a novel fibrinogenase (FII) showed protective effects on LPS-induced DIC via activating protein C and suppressing inflammatory cytokines.

OBJECTIVE

To evaluate whether FII has protective effect on LPS-induced endotoxemia in mice and learn about the role of NF-κB pathway in TNF-α producing process.

METHODS

BALB/C mice were intraperitoneally injected (i.p.) with (a) 30 mg/kg LPS, (b) LPS + 0.3 mg/kg FII, (c) LPS + 1.0 mg/kg FII, (d) LPS + 3.0 mg/kg FII or (e) saline. Both survival rate and organ function were tested, including alanine aminotransferase (ALT), blood urine nitrogen (BUN) and tissue section, and TNF-α was examined by ELISA. RAW 264.7 macrophage was administered with (a) LPS, (b) LPS + FII, (c) FII alone or (d) saline, and TNF-α and phosphorylation (P)-NF-κB (P65) were determined by Western blot.

RESULTS

The administration of LPS led to 65% mortality rate, a rise of serum TNF-α, BUN and ALT levels, and both liver and renal tissue damage were observed. While FII treatment significantly increased the survival rate of LPS-induced endotoxemia mice model, histopathology and protein analysis results also revealed that FII remarkably protected liver and renal from LPS damage as well as decreasing TNF-α level. In vitro, FII significantly decreased LPS-induced TNF-α production and the expression of P-NF-κB (P65).

CONCLUSIONS

Our findings suggested that FII had protective effect on LPS-induced endotoxemia and organ injuries by suppressing the activation of NF-κB which decreased TNF-α level.

Attenuation of LPS-induced cyclooxygenase-2 and inducible NO synthase expression by lysophosphatidic acid in macrophages

LPS can activate the inflammatory cascades by inducing various inflammatory mediators, such as prostaglandin E2 (PGE2) resulting from cyclooxygenase-2 (COX-2), and NO produced by inducible NO synthase (iNOS). Lysophosphatidic acid (LPA) has been demonstrated to participate in inflammation. This study aimed to clarify the impact and the involving mechanisms of LPA on LPS-incurred inflammation in macrophages. First, LPA appeared to attenuate LPS-induced protein and mRNA expression of COX-2 and iNOS genes, as well as production of PGE2 and NO. By using selective inhibitors targeting various signaling players, the inhibitory G protein alpha subunit (Gαi) seemed to be involved in the effect of LPA; p38, ERK and NF-κB were involved in the LPS-mediated COX-2/PGE2 pathway; and p38, JNK, phosphoinositide-3-kinase and NF-κB were involved in the LPS-mediated iNOS/NO pathway. LPA was able to diminish LPS-induced phosphorylation of p38 and Akt, as well as NF-κB p65 nuclear translocation. By utilization of inhibitors of COX-2 and iNOS, there appeared to be no modulation between the COX-2/PGE2 and the iNOS/NO signaling pathways. Our findings demonstrate a clear anti-inflammatory role of LPA acting via Gαi in LPS-mediated inflammatory response in macrophages, owing, at least in part, to its suppressive effect on LPS-induced activation of p38, Akt and NF-κB.