Protective effect of baicalein against endotoxic shock in rats in vivo and in vitro

Analyzing the molecular mechanism of Scutellaria Radix in the treatment of sepsis using RNA sequencing

BACKGROUND

Sepsis is a life-threatening organ dysfunction, which seriously threatens human health. The clinical and experimental results have confirmed that Traditional Chinese medicine (TCM), such as Scutellariae Radix, has anti-inflammatory effects. This provides a new idea for the treatment of sepsis. This study systematically analyzed the mechanism of Scutellariae Radix treatment in sepsis based on network pharmacology, RNA sequencing and molecular docking.

METHODS

Gene expression analysis was performed using Bulk RNA sequencing on sepsis patients and healthy volunteers. After quality control of the results, the differentially expressed genes (DEGs) were analyzed. The active ingredients and targets of Scutellariae Radix were identified using The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Gene Ontology (GO) and Protein-Protein Interaction (PPI) analysis were performed for disease-drug intersection targets. With the help of GEO database, Survival analysis and Meta-analysis was performed on the cross-targets to evaluate the prognostic value and screen the core targets. Subsequently, single-cell RNA sequencing was used to determine where the core targets are located within the cell. Finally, in this study, molecular docking experiments were performed to further clarify the interrelationship between the active components of Scutellariae Radix and the corresponding targets.

RESULTS

There were 72 active ingredients of Scutellariae Radix, and 50 common targets of drug and disease. GO and PPI analysis showed that the intersection targets were mainly involved in response to chemical stress, response to oxygen levels, response to drug, regulation of immune system process. Survival analysis showed that PRKCD, EGLN1 and CFLAR were positively correlated with sepsis prognosis. Meta-analysis found that the three genes were highly expressed in sepsis survivor, while lowly in non-survivor. PRKCD was mostly found in Macrophages, while EGLN1 and CFLAR were widely expressed in immune cells. The active ingredient Apigenin regulates CFLAR expression, Baicalein regulates EGLN1 expression, and Wogonin regulates PRKCD expression. Molecular docking studies confrmed that the three active components of astragalus have good binding activities with their corresponding targets.

CONCLUSIONS

Apigenin, Baicalein and Wogonin, important active components of Scutellaria Radix, produce anti-sepsis effects by regulating the expression of their targets CFLAR, EGLN1 and PRKCD.

Investigation of the protective activity of baicalein on the lungs via regulation of various cellular responses in rats exposed to experimental sepsis

Backgrounds

In the present study, a cecal ligation and puncture (CLP)-induced experimental sepsis rat model was used to explore the effects of baicalein on inflammatory cytokine levels and oxidative stress as well as the possible regulatory role of nuclear factor-kappa B (NF-κB).

Methods

For that purpose, 42 Wistar albino rats were equally divided into control, sham, sepsis, B50 + S, B100 + S, S + B50, and S + B100 groups. The B50 + S and B100 + S groups received baicalein before the induction of sepsis, while the S + B50 and S + B100 groups received baicalein afterwards. Experimental sepsis in related groups is generated through ligation of cecum and a puncture in cecal wall. Serum samples were used for tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) analyses, and tissue Malondialdehyde (MDA), Superoxide dismutase (SOD), Glutathione (GSH), IL-6, and NF-κB levels were measured.

Results

Compared to the control group, there were significantly increases in the serum TNF-α, IL-6, tissue MDA, and NF-κB levels and decreases in the tissue SOD and GSH levels in the septic group (P < 0.05). Compared to the septic group, inflammation and oxidative stress were reduced in the baicalein-treated groups. Although all of the pre- and post-treatment protocols alleviated inflammation and oxidative stress to varying degrees, pre-treatment with 100 mg/kg was the most successful.

Conclusions

Findings of this study indicated that baicalein has the potential to reduce sepsis-related oxidative stress and inflammation in the lungs and that pathological outcomes could be regulated via NF-κB transcription factor activity.

Two flavonoids, baicalein and naringin, are effective as anti-inflammatory and anti-oxidant agents in a rat model of polymicrobial sepsis

INTRODUCTION

In this study, our aim was to investigate the possible protective and therapeutic effects of these two flavonoids, baicalein, and naringin, in 50 and 100 mg/kg doses applied both before and after cecal ligation and puncture (CLP) procedures in a polymicrobial sepsis rat model, and evaluate the possible contribution of oxidative and inflammatory markers by immunological, biochemical, molecular, and histopathological methods.

METHODS

Sixty-six Wistar albino rats were divided into 11 groups. The pro-inflammatory (TNF-alpha, IL-1-beta, and IL-6) and anti-inflammatory (TGF-beta and IL-10) cytokine levels were measured by ELISA technique. CD3, CD68, and nuclear factor kappa B positivity rates were detected by immunohistochemical methods. Oxidative stress parameters (MDA, SOD, and GSH) were measured by tissue biochemistry.

RESULTS

Sepsis caused a significant increase in all pro-inflammatory cytokine levels and MDA activity. Also, it led to an increase in the positivities of CD3, CD68, and NF-κB markers. However, especially pre-CLP doses of baicalein and naringin inhibited the inflammation process by suppressing pro-inflammatory and increasing anti-inflammatory cytokine levels, as well as regulating the oxidative stress process by normalizing the oxidant/anti-oxidant enzyme levels.

CONCLUSION

Both pre- and post-application of baicalein and naringin are quite effective to prevent sepsis-caused cellular processes. This protective and therapeutic effects by baicalein and naringin in animals with sepsis seems to be originated from the high antioxidant capacity and inhibition of pro-inflammatory cytokine production. Thus, those natural agents may prove to be valuable protective agent against septic shock.

Promising Role of the Scutellaria baicalensis Root Hydroxyflavone-Baicalein in the Prevention and Treatment of Human Diseases

Plant roots, due to a high content of natural antioxidants for many years, have been used in herbal medicine. It has been documented that the extract of Baikal skullcap (Scutellaria baicalensis) has hepatoprotective, calming, antiallergic, and anti-inflammatory properties. Flavonoid compounds found in the extract, including baicalein, have strong antiradical activity, which improves overall health and increases feelings of well-being. Plant-derived bioactive compounds with antioxidant activity have for a long time been used as an alternative source of medicines to treat oxidative stress-related diseases. In this review, we summarized the latest reports on one of the most important aglycones with respect to the pharmacological activity and high content in Baikal skullcap, which is 5,6,7-trihydroxyflavone (baicalein).

Black Garlic and Thiosulfinate-Enriched Extracts as Adjuvants to Ceftriaxone Treatment in a Rat Peritonitis Model of Sepsis

To date, there have been no new drugs or adjuvants able to decrease both morbidity and mortality in the context of sepsis and septic shock. Our objective was to evaluate the use of thiosulfinate-enriched Allium sativum and black garlic extracts as adjuvants in the management of sepsis. An experimental in vivo study was carried out with male Sprague-Dawley^® rats. Animals were randomized in four treatment groups: antibiotic (ceftriaxone) treatment (group I), ceftriaxone plus thiosulfinate-enriched extract (TASE, group II), ceftriaxone plus thiosulfinate-enriched extract and black garlic extracts (TASE + BGE, group III), and ceftriaxone plus black garlic extract (BGE, group IV). All animals were housed and inoculated with 1 × 10¹⁰ CFU/15 mL of intraperitoneal Escherichia coli ATCC 25922. Subsequently, they received a daily treatment according to each group for 7 days. Clinical, analytical, microbiological, and histopathological parameters were evaluated. Statistically significant clinical improvement was observed in rats receiving garlic extracts in weight (groups II and III), ocular secretions, and piloerection (group IV). Moreover, less liver edema, vacuolization, and inflammation were observed in groups receiving adjuvant support (groups II, III, and IV). When comparing interleukins 24 h after bacteria inoculum, we found statistically significant differences in TNF-alpha levels in groups receiving BGE (groups III and IV, p ≤ 0.05). Blood and peritoneal liquid cultures were also analyzed, and we detected a certain level of Enterococcus faecalis in peritoneal cultures from all treatment groups and less bacteria presence in blood cultures in rats receiving garlic extracts (groups II, III, and IV). In conclusion, TASE and BGE could be promising nutraceutical or medicinal agents as coadjuvants in the treatment of sepsis because of its effects in modulating the inflammatory response.

Naringinin ratlarda bakteriyel endotoksin kaynaklı ince bağırsak hasarı üzerindeki anti-inflamatuvar ve anti-apoptotik etkileri

Amaç. Bu çalışmanın amacı, birçok biyolojik özelliği bulunan naringinin (NRG) ratlarda bakteriyel endotoksin kaynaklı ince bağırsak hasarı üzerine anti-inflamatuar ve antiapoptotik etkilerinin araştırılmasıdır. Gereç ve Yöntem: Bu amaçla, 40 adet dişi Wistar albino ırkı rat 4 gruba ayrılmıştır: Kontrol (hiçbir uygulama yapılmayan grup), LPS (10 mg/kg/ip lipopolisakkarit uygulanan grup), NRG (14 gün boyunca 100 mg/kg/ip naringin uygulanan grup) ve LPS+NRG (10 mg/kg/ip lipopolisakkarit uygulamasından önce 14 gün boyunca naringin uygulanan grup). Deneysel prosedürün uygulanmasından sonra, deney hayvanlarının ince barsak dokuları çıkarıldı ve doku takibi protokolüne göre hazırlandı. Barsak dokusundaki histopatolojik değişiklikleri değerlendirmek amacıyla Hematoksilen-Eozin boyaması gerçekleştirildi ve histopatolojik değişiklikler açısından deney gruplarının karşılaştırılması amacıyla hasar skorlaması yapıldı. Ayrıca, immunohistokimyasal boyamalar ile TNF- ve Kaspaz-3 ekspresyon seviyeleri belirlendi ve gruplar arasında bu proteinlerin ekspresyon seviyelerindeki değişikliklerin belirlenmesi için immunohistokimyasal boyanma yoğunluğu skorlandı. Bulgular: LPS grubunda epitel ve Brunner bezlerinde hasar, mononüklear hücre infiltrasyonu, hemorajik alanlar belirlendi. Ayrıca TNF- ve Kaspaz-3 ekspresyonları bu grupta anlamlı bir şekilde arttı. Ancak, NRG uygulamaları bu parametreler açısından LPS+NRG grubundaki deney hayvanlarının ince barsak dokusunda güçlü bir koruyucu etki gösterdi. Sonuç: Bu çalışma, 100 mg/kg NRG enjeksiyonunun endotoksin kaynaklı enfeksiyonun bağırsak mukozası üzerindeki olumsuz etkilerine karşı koruyucu bir ajan olarak kabul edilebileceğini ve daha ileri klinik çalışmalarda göz ardı edilmemesi gerektiğini göstermiştir.

Acute ammonia stress-induced oxidative and heat shock responses modulated by transcription factors in Litopenaeus vannamei

The present study aimed to examine the effects of short-term exposure to ammonia on stress and oxidative responses in shrimp (Litopenaeus vannamei) and to determine whether the antioxidant system related to the regulatory role of transcription factors and stress proteins was activated. Shrimp were exposed ammonia-N at four concentrations: 0 (control), 5, 10, and 15 mg/L, for 48 h. The hepatopancreas was sampled to measure the levels of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO); the activities of superoxide dismutase (SOD), catalase (CAT), nitric oxide synthase (NOS); and the expression levels of GSH-px (encoding glutathione peroxidase), GST (encoding glutathione-S-transferase), HSP70 (encoding heat shock protein 70), HSP90 (encoding heat shock protein 90), p53, RELISH, and AKIRIN. We observed that exposure to a high ammonia content increased the abundance of oxidative factors (MDA, CAT, SOD, NOS, and NO), reduced the levels of GSH, and upregulated the mRNA expression levels of antioxidant genes (GSH-px and GST), stress-related genes (HSP70 and HSP90), and transcription factor genes (p53, RELISH, and AKIRIN). These results indicated that ammonia induced oxidative stress and inflammation. Both enzymatic and nonenzymatic antioxidant defense systems are involved, which might be regulated by HSPs, as well as certain transcription factors, such as p53 and nuclear factor kappa B (NF-κB), thus mounting an adaptive response to help rebalance redox homoeostasis.

Protective and therapeutic effects of Scutellaria baicalensis and its main active ingredients baicalin and baicalein against natural toxicities and physical hazards: a review of mechanisms

OBJECTIVES

Scutellaria baicalensis (SB) has been traditionally used to combat a variety of conditions ranging from ischemic heart disease to cancer. The protective effects of SB are due to the action of two main flavonoids baicalin (BA) and baicalein (BE). This paper aimed to provide a narrative review of the protective and antidotal effects of SB and its main constituents against natural toxicities and physical hazards.

EVIDENCE ACQUISITION

Scientific databases Medline, Scopus, and Web of Science were thoroughly searched, based on different keywords for in vivo, in vitro and clinical studies which reported protective or therapeutic effects of SB or its constituents in natural and physical toxicities.

RESULTS

Numerous studies have reported that treatment with BE, BA, or total SB extract prevents or counteracts the detrimental toxic effects of various natural compounds and physical hazards. The toxic agents include mycotoxins, lipopolysaccharide, multiple plants and animal-derived substances as well as physical factors which negatively affected vital organs such as CNS, liver, kidneys, lung and heart. Increasing the expression of radical scavenging enzymes and glutathione content as well as inhibition of pro-inflammatory cytokines and pro-apoptotic mediators were important mechanisms of action.

CONCLUSION

Different studies on the Chinese skullcap have exhibited that its total root extract, BA or BE can act as potential antidotes or protective agents against the damage induced by natural toxins and physical factors by alleviating oxidative stress and inflammation. However, the scarcity of high-quality clinical evidence means that further clinical studies are required to reach a more definitive conclusion.

Baicalein Attenuates Severe Polymicrobial Sepsis via lleviating Immune Dysfunction of T Lymphocytes and Inflammation

OBJECTIVE

To investigate the effect of baicalein on polymicrobial sepsis-induced immune dysfunction and organ injury.

METHODS

A sepsis model was induced in Sprague-Dawley rats via caecal ligation and puncture (CLP). Specific pathogen free rats were randomly divided into a sham group, CLP group and CLP + baicalein (Bai) group (n=16 each). Rats in the CLP + Bai group were intravenously injected with baicalein (20 mg/kg) at 1 and 10 h after CLP. Survival rate, bacterial load, and organ damage were assessed. Then each group was evaluated at 6, 12, and 24 h to investigate the effect of baicalein on immune cells and inflammatory cytokines in septic rats.

RESULTS

Baicalein treatment significantly improved the survival of septic rats, decreased the bacterial burden, and moderated tissue damage (spleen, liver, and lung), as observed by haematoxylin and eosin staining. Septic rats treated with baicalein had strikingly increased proportions of CD3⁺CD4⁺ T cells and ratios of CD4⁺/CD8⁺ T cells in the peripheral blood and spleen (all P<0.05). Moreover, baicalein treatment decreased the apoptotic rate of whole white blood cells and spleen cells at 24 h after surgery (P<0.05). Baicalein significantly reduced the levels of tumor necrosis factor α and interleukin-6 (IL-6) and increased IL-10, and the expression levels of galectin 9 were also raised in the spleen (P<0.01).

CONCLUSION

Baicalein may be an effective immunomodulator that attenuates overwhelming inflammatory responses in severe abdominal sepsis.

An overview of pharmacological activities of baicalin and its aglycone baicalein: New insights into molecular mechanisms and signaling pathways

The flavonoids, baicalin, and its aglycone baicalein possess multi-fold therapeutic properties and are mainly found in the roots of Oroxylum indicum (L.) Kurz and Scutellaria baicalensis Georgi. These flavonoids have been reported to possess various pharmacological properties, including antibacterial, antiviral, anticancer, anticonvulsant, anti-oxidant, hepatoprotective, and neuroprotective effects. The pharmacological properties of baicalin and baicalein are due to their abilities to scavenge reactive oxygen species (ROS) and interaction with various signaling molecules associated with apoptosis, inflammation, autophagy, cell cycle, mitochondrial dynamics, and cytoprotection. In this review, we summarized the molecular mechanisms underlying the chemopreventive and chemotherapeutic applications of baicalin and baicalein in the treatment of cancer and inflammatory diseases. In addition, the preventive effects of baicalin and baicalein on mitochondrial dynamics and functions were highlighted with a particular emphasis on their anti-oxidative and cytoprotective properties. The current review highlights could be useful for future prospective studies to further improve the pharmacological applications of baicalein and baicalin. These studies should define the threshold for optimal drug exposure, dose optimization and focus on therapeutic drug monitoring, objective disease markers, and baicalin/baicalein drug levels.

Baicalein suppresses lipopolysaccharide-induced acute lung injury by regulating Drp1-dependent mitochondrial fission of macrophages

Acute lung injury (ALI) and its serious form, the acute respiratory distress syndrome (ARDS) are devastating diseases without effective chemotherapy. Exuberant or uncontrolled proinflammation responses in the lung, also known as "cytokine storms", is one of the main culprits in the pathogenesis of organ failure, and anti-inflammatory therapy is essential to alleviate ALI/ARDS-associated injuries. Emerging evidence suggests that baicalein has potent anti-inflammatory and antioxidant properties. However, the underlined mechanism of baicalein to mitigate inflammation in ALI remains unclear. Herein, we demonstrated a critical role for baicalein in suppressing the inflammatory response of LPS-activated macrophages. We found that mitochondria function was restored in the condition of baicalein. Interestingly, results showed that mitochondrial dysfunction positively correlates with inflammatory cytokine generation at each corresponding baicalein concentration. Further mRNA analysis revealed that baicalein mitigates mitochondrial defects via attenuation of dynamin-related protein 1 (Drp1) expression. These reprogrammed mitochondria prevent their function shift from the ATP synthesis to reactive oxygen species (ROS) production after the LPS challenge, thereby dampening NF-κB-dependent inflammatory cytokine transcription. Baicalein reduces the production of inflammatory mediators TNF-α, MIP-1, IL-6, and diminishes neutrophil influx and severity of endotoxin-mediated ALI. Taken together, our results show that baicalein may serve as a new clinical therapeutic strategy in ALI by modulating Drp1-induced mitochondrial impairment, restraining inflammatory responses, and reducing the severity of lung injury.

Potential role of herbal medicines as a novel approach in sepsis treatment

The growing number of deaths related to sepsis has become a major concern for past few years. Sepsis is a complex pathological reactions that is explained by series of host response to microbial insult. The resulted systemic reactions are manifested by early appearance of proinflammatory cytokines leading to hyperinflammatory phase which is followed by septic shock and death of the patient. The present study has revealed that antibiotics are not self-sufficient to control the complex mechanism of sepsis. Moreover prolonged and unnecessary administration of antibiotics may lead to antibiotic resistance to pathogens. In addition to this, immunosuppressive medications are selective and have targeted approach to certain study population. Drugs from herbal origin have shown to possess a mammoth of immunomodulatory potential by suppressing proinflammatory and anti-inflammatory cytokines exhibiting no or minimal unwanted secondary responses. Concomitantly, herbal plants tend to modulate oxidative stress level and haematological imbalance during inflammatory diseased conditions. Natural compounds have gained much attention for the treatment of several clinical complications. Considering the promising responses of medicinal plants with less/no side effects and easy procurement, comprehensive research on herbal plants to treat sepsis should be contemplated.

Modulations of Cardiac Functions and Pathogenesis by Reactive Oxygen Species and Natural Antioxidants

Homeostasis in the level of reactive oxygen species (ROS) in cardiac myocytes plays a critical role in regulating their physiological functions. Disturbance of balance between generation and removal of ROS is a major cause of cardiac myocyte remodeling, dysfunction, and failure. Cardiac myocytes possess several ROS-producing pathways, such as mitochondrial electron transport chain, NADPH oxidases, and nitric oxide synthases, and have endogenous antioxidation mechanisms. Cardiac Ca²⁺-signaling toolkit proteins, as well as mitochondrial functions, are largely modulated by ROS under physiological and pathological conditions, thereby producing alterations in contraction, membrane conductivity, cell metabolism and cell growth and death. Mechanical stresses under hypertension, post-myocardial infarction, heart failure, and valve diseases are the main causes for stress-induced cardiac remodeling and functional failure, which are associated with ROS-induced pathogenesis. Experimental evidence demonstrates that many cardioprotective natural antioxidants, enriched in foods or herbs, exert beneficial effects on cardiac functions (Ca²⁺ signal, contractility and rhythm), myocytes remodeling, inflammation and death in pathological hearts. The review may provide knowledge and insight into the modulation of cardiac pathogenesis by ROS and natural antioxidants.

The role of phytochemicals in sepsis: A mechanistic and therapeutic perspective

Sepsis and septic shock are still a leading cause of mortality and morbidity in intensive care units worldwide. Sepsis is an uncontrolled and excessive response of the innate immune system toward the invading infectious microbes, characterized by the hyper-production of pro-inflammatory mediators such as interleukin (IL)-1β, IL-6, tumor-necrosis factor (TNF)-α, and high-mobility group box 1 (HMGB1). In severe sepsis, the overwhelming production of pro-inflammatory cytokines and reactive oxygen species may compromise organ function and lead to the induction of abnormal apoptosis in different organs, resulting in multiple organ dysfunction syndrome and death. Hence, compounds that are able to attenuate inflammatory responses may have therapeutic potential for sepsis treatment. Understanding the pathophysiology and underlying molecular mechanisms of sepsis may provide useful insights in the discovery and development of new effective therapeutics. Therefore, numerous studies have invested much effort into elucidating the mechanisms involved with the onset and development of sepsis. The present review mainly focuses on the molecules and signaling pathways involved in the pathogenicity of sepsis. Additionally, several well-known natural bioactive herbal compounds and phytochemicals, which have shown protective and therapeutic effects with regard to sepsis, as well as their mechanisms of action, are presented. This review suggests that these phytochemicals are able to attenuate the overwhelming inflammatory responses developed during sepsis by modulating different signaling pathways. Moreover, the anti-inflammatory and cytoprotective activities of phytochemicals make them potent compounds to be included as complementary therapeutic agents in the diets of patients suffering from sepsis in an effort to alleviate sepsis and its life-threatening complications, such as multi-organ failure.

Network pharmacology based research into the effect and mechanism of Xijiao Dihuang decoction against sepsis

Sepsis is a critical illness that contributes a high mortality, while Xijiao Dihuang decoction (XJDHT) has been used in treatment against sepsis for many years by clinical doctors. Clinical studies confirmed a good efficacy of XJDHT against sepsis. The aim of this study is to observe the efficacy of XJDHT in sepsis model rats and macrophages activated by LPS, and to verify the underlying mechanisms. The key components of XJDHT and its targets against sepsis were analyzed and selected by network pharmacology. The potential mechanisms that XJDHT regulates the progress of sepsis were verified in sepsis rats and NR8383 cell lines. XJDHT at a dose of 25 mg/kg was administrated to rats which endured cecal ligation and perforation (CLP). After MTT assay, XJDHT at a dose of 4 mg/mL was selected to treat NR8383 cell lines activated by LPS. In vivo experiment, the survival of the rats was assessed. The content of cytokine in serum were assessed by Enzyme-linked immunosorbent assays (ELISA). Contents of cytokine and key molecules in relative signaling pathway were assessed by immunohistochemical method. The pathway protein expressions were detected by Western blotting. In vitro experiment, immunofluorescence was used to assess the content of cytokine and signaling pathway. A total of 42 targets of XJDHT against sepsis were identified by network pharmacology. After eliminating overlapping compounds and proteins, there were 8 compounds in XJDHT that associating with the 42 sepsis-related targets. NF-κB and HIF-1α signaling pathway were recognized to play important role for XJDHT against sepsis. XJDHT improved survival rate in the XJDHT group compared with the model group. The contents of IL-6 increased in the model group compared with the control group with ELISA and immunohistochemistry, while XJDHT reduced the content of IL-6. The expressions of p65 and HIF-1α reduced significantly in the XJDHT group compared with the model group. In vitro study, the content of IL-6 elevated significantly after LPS stimulation, while XJDHT reduced this increase. Furthermore, expressions of protein of p65 and HIF-1α decreased significantly compared with the LPS group. To conclude, our study demonstrated that XJDHT at a dose of 25 g/kg is capable of improving the survival of sepsis via regulating the NF-κB and HIF-1α signaling pathway.

NADPH oxidase is a primary target for antioxidant effects by inorganic nitrite in lipopolysaccharide-induced oxidative stress in mice and in macrophage cells

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and oxidative stress is usually considered as an important factor to the pathogenesis of various diseases. Inorganic nitrite, previously viewed as a harmful substance in our diet or inert metabolites of endogenous NO, is recently identified as an important biological NO reservoir in vasculature and tissues. Stimulation of a nitrite-NO pathway shows organ-protective effects on oxidative stress and inflammation, but the mechanisms or target are not clear. In this study, the hypothesis that inorganic nitrite attenuated lipopolysaccharide (LPS)-induced oxidative stress in mice and in macrophage cells by modulating NADPH oxidase activity and NO bioavailability were investigated. We showed that nitrite treatment, in sharp contrast with the worsening effect of NO synthases inhibition, significantly attenuated aortic oxidative stress, endothelial dysfunction and mortality in LPS-induced shock in mice. Mechanistically, protective effects of nitrite were abolished by NO scavenger and xanthine oxidase inhibitor, and inhibition of NADPH oxidase with apocynin attenuated LPS-induced oxidative stress similar to that of nitrite. In the presence of nitrite, no further effect of apocynin was observed, suggesting NADPH oxidase as a possible target. In LPS-activated macrophage cells, nitrite reduced NADPH oxidase activity and oxidative stress and these effects of nitrite were also abolished by NO scavenger and xanthine oxidase inhibitor, where xanthine oxidase-mediated reduction of nitrite attenuated NADPH oxidase activity in activated macrophages via a NO-dependent mechanism. In conclusion, these novel findings position NADPH oxidase in the inflammatory vasculature as a prime target for the antioxidant effects of inorganic nitrite, and open a new direction to modulate the inflammatory response.

Synergistic anti-inflammatory effects of quercetin and catechin via inhibiting activation of TLR4-MyD88-mediated NF-κB and MAPK signaling pathways

The synergistic anti-inflammatory effect of quercetin and catechin was investigated using lipopolysaccharide (LPS)-stimulated macrophage RAW 264.7 cells. Results showed that the combined treatment of quercetin with catechin synergistically attenuated LPS-stimulated increase of some proinflammatory molecules, including nitric oxide, tumor necrosis factor α, interleukin-1β, nitric oxide synthase, and cyclooxygenase-2. Moreover, it exhibited significantly (p < 0.05) stronger inhibitory effect on nuclear translocation of nuclear factor-κB (NF-κB) by suppressing the phosphorylation of NF-κB p65 and p50 submits and on the phosphorylation of ETS domain-containing protein and c-Jun N-terminal kinase than any of quercetin or catechin alone. Besides, the cotreatment of quercetin with catechin significantly (p < 0.05) restored the impaired expression of toll-like receptor 4, myeloid differentiation primary response gene 88, and some downstream effectors (IRAK1, TRAF6, and TAK1). These results suggest that quercetin and catechin possessed synergistic anti-inflammatory effects, which may be attributed to their roles in suppressing the activation of TLR4-MyD88-mediated NF-κB and mitogen-activated protein kinases signaling pathways.

Luteolin suppresses lipopolysaccharide‑induced cardiomyocyte hypertrophy and autophagy in vitro

Luteolin (LTL) serves essential roles in a wide variety of biological processes. Lipopolysaccharide (LPS) can lead to myocardial hypertrophy and autophagy. However, the roles of LTL on LPS-induced cardiomyocyte hypertrophy and autophagy in rat cardiomyocytes have not yet been fully elucidated. In the present study, the morphology of cultured rat cardiomyocytes was observed under an inverted microscope. Cell viability was detected by MTT assay. α-Actinin and microtubule-associated protein 1 light chain 3 (LC3) expression levels were measured by immunofluorescence assay. In addition, the expression levels of atrial natriuretic peptide/brain natriuretic peptide (ANP/BNP), LC3, and autophagy- and Wnt signaling pathway-associated genes were analyzed by reverse transcription-quantitative polymerase chain reaction or western blot assays. The results indicated that LTL increased the cell viability of cardiomyocytes treated with LPS. LTL decreased the expression of cardiac hypertrophy associated markers (ANP and BNP). LTL decreased α-actinin and LC3 expression levels in LPS-treated cardiomyocytes. It was also demonstrated that LTL suppressed the mRNA and protein expression levels of LPS-mediated autophagy and Wnt signaling pathway-associated genes. In addition, it was demonstrated that silencing of β-catenin inhibited LPS-induced cardiomyocyte hypertrophy and the formation of autophagosomes. Thus, the present study suggested that LTL protected against LPS-induced cardiomyocyte hypertrophy and autophagy in rat cardiomyocytes.

Comparison of anti-inflammatory effects of berberine, and its natural oxidative and reduced derivatives from Rhizoma Coptidis in vitro and in vivo

BACKGROUND

Berberine (BBR) is the most abundant and major active constituent of Rhizoma Coptidis (RC), which has been widely used to treat inflammatory diseases in traditional oriental medicine. Despite BBR has been found to exhibit pronounced anti-inflammatory effect, the anti-inflammatory activities of its natural derivatives were sparsely dissected out.

PURPOSE

To comparatively investigate the anti-inflammatory potential of BBR, and its natural oxoderivative (oxyberberine, OBB) and reduced derivative (dihydroberberine, DHBB) in vitro and in vivo, and delineate the possible underlying mechanism.

METHODS

LC-MS/MS was used to identify the natural derivatives of BBR in RC. The potential anti-inflammatory properties of BBR and its natural derivatives were comparatively evaluated in vitro by lipopolysaccharide (LPS)-induced RAW264.7 macrophages cells, and in vivo via three typical acute inflammation murine models. Some important inflammation-related molecules were analyzed by ELISA, qRT-PCR and Western blotting.

RESULTS

LC-MS/MS led to the identification of BBR, OBB and DHBB in RC ethyl acetate extract. The in vitro assay indicated that BBR, OBB and DHBB (1.25, 2.5 and 5 μM) pretreatment significantly decreased the levels of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), prostaglandinE2 (PGE₂) and nitricoxide (NO), and inhibited the mRNA expressions of cyclooxygenase-2 (COX-2) and inducible nitricoxide synthase (iNOS) in a dose-dependent manner, with relative efficiency of OBB > BBR > DHBB. Furthermore, OBB, BBR and DHBB remarkably inhibited the phosphorylation of nuclear factor-κB (NF-κB) p65 and inhibitory kappa Bα (IκBα). In vivo, BBR (20 mg/kg) and OBB (5, 10, and 20 mg/kg) pretreatment significantly ameliorated the xylene-induced ear edema, carrageenan-stimulated paw edema, and acetic acid-elicited vascular permeability in mice in a dose-dependent manner, with OBB exhibiting superior anti-inflammatory effect at the same dose (20 mg/kg). Histopathological analysis indicated that OBB and BBR could markedly attenuate the inflammatory deterioration and decrease the cellular infiltration in paw tissues. Additionally, the carrageenan-induced increases in TNF-α, IL-6, IL-1β, PGE₂ and NO productions, and COX-2 and iNOS mRNA expressions were effectually and concentration-dependently suppressed by OBB and BBR pretreatment.

CONCLUSION

The anti-inflammatory activity of BBR and its natural derivatives was in the order of OBB > BBR > DHBB. OBB was for the first time found to be endowed with pronounced anti-inflammatory property, which was probably associated with suppressing the activation of NF-κB signaling pathway, and the subsequent gene expressions and productions of pro-inflammatory mediators. The results might contribute to illuminating the pharmacodynamic underpinnings of RC and provide evidence for developing OBB as a safe and promising natural lead compound in inflammation treatment.

Semi-Mechanism-Based Pharmacodynamic Model for the Anti-Inflammatory Effect of Baicalein in LPS-Stimulated RAW264.7 Macrophages

Monitoring of the inhibition of TNF-α, IL-6, iNOS, and NO is used to effectively evaluate anti-inflammatory drugs. Baicalein was found to have good anti-inflammatory activities, but its detailed cellular pharmacodynamic events have not been expatiated by any other study. The inflammatory mediators, including TNF-α, IL-6, iNOS, and NO production in RAW264.7 macrophage induced by LPS, were measured. It was found that these data showed a sequential pattern on time and based on these points a cellular pharmacodynamic model was developed and tested. TNF-α and IL-6 were quantified by ELISA, NO was detected by Griess and iNOS expression was measured by Western blot. The pharmacodynamic model was developed using a NLME modeling program Monolix® 2016R1.¹The results showed that baicalein quickly suppressed release of TNF-α in a concentration-dependent manner, and consequently causing the diminution of IL-6 and iNOS/NO. The pharmacodynamic model simulation successfully described the experimental data, supporting the hypothesis that IL-6 and iNOS /NO release after LPS stimulation is mediated by TNF-α rather than LPS directly. The pharmacodynamic model allowed a well understanding of the cellular pharmacodynamic mechanism of baicalein in the treatment of inflammatory diseases.

Baicalein Ameliorates Pulmonary Arterial Hypertension Caused by Monocrotaline through Downregulation of ET-1 and ETAR in Pneumonectomized Rats

Baicalein (BE) extracted from Scutellaria baicalensis Georgi is able to alleviate various cardiovascular and inflammatory diseases. However, the effects of BE on pulmonary arterial hypertension (PAH) remain unknown. Therefore, the present study aimed to examine whether BE ameliorates pneumonectomy and monocrotaline-induced PAH in rats and further investigate the underlying molecular mechanisms. Administration of BE greatly attenuated the development of PAH as evidenced by an improvement of its characteristic features, including elevation of right ventricular systolic pressure, right ventricular hypertrophy, and pulmonary vascular remodeling. Moreover, the increased protein expression of endothelin-1 (ET-1) and ETA receptor (ETAR), superoxide overproduction, and activation of Akt/ERK1/2/GSK3[Formula: see text]/[Formula: see text]-catenin pathway that occurred in the lungs of PAH rats were markedly reversed by BE treatment. Compared with the untreated PAH rats, higher expression of endothelial nitric oxide synthase (eNOS), but lower levels of inducible nitric oxide synthase and vWF were observed in BE-treated PAH rats. Collectively, treatment with BE remarkably attenuates the pathogenesis of PAH, and the protection of BE may be associated with suppressing Akt/Erk1/2/GSK3[Formula: see text]/[Formula: see text]-catenin/ET-1/ETAR signaling and preventing endothelial dysfunction. These results suggest that BE is a potential agent for treatment of PAH.

Protective effect of acacetin on sepsis-induced acute lung injury via its anti-inflammatory and antioxidative activity

Sepsis is a clinical syndrome with no effective protective or therapeutic treatments. Acacetin, a natural flavonoid compound, has anti-oxidative and anti-inflammatory effects which can potentially work to reduce sepsis. We investigated the potential protective effect of acacetin on sepsis-induced acute lung injury (ALI) ALI and dissect out the underlying mechanisms. Mice were divided into five groups: a sham group, a sepsis-induced ALI group, and three sepsis groups pre-treated with 20, 40, and 80 mg/kg body weight of acacetin. We found that acacetin significantly attenuated sepsis-induced ALI, in histological examinations and lung edema. Additionally, acacetin treatment decreased protein and inflammatory cytokine concentration and the number of infiltrated inflammatory cells in BALF compared with that in the non-treated sepsis mice. Pulmonary myeloperoxidase (MPO) activity was lower in the acacetin-pre-treated sepsis groups than in the sepsis group. The mechanism underlying the protective effect of acacetin on sepsis is related to the regulation of certain antioxidation genes, including inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), superoxide dismutases (SODs), and heme oxygenase 1 (HO-1).Taken together, our results indicate that acacetin pre-treatment inhibits sepsis-induced ALI through its anti-inflammatory and antioxidative activity, suggesting that acacetin may be a potential protective agent for sepsis-induced ALI.

The flavonoid Baicalein attenuates cuprizone-induced demyelination via suppression of neuroinflammation

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system characterized by recurrent and progressive demyelination/remyelination cycles, neuroinflammation, oligodendrocyte loss, and axonal pathology. Baicalein isolated from the roots of Scutellaria baicalensis has been shown to exert anti-inflammatory and antioxidant effects. The cuprizone model is an established mouse model of MS and causes demyelination and motor dysfunction and induces neuroinflammation, such as glial activation and pro-inflammatory cytokine production. To determine whether Baicalein attenuates cuprizone-induced demyelination, we administrated Baicalein to cuprizone-exposed mice. Baicalein attenuated weight loss (P<0.05) and motor dysfunction (P<0.05) in the cuprizone model mice. Baicalein treatment effectively suppressed the demyelination (P<0.01) and gene expressions of CNP (P<0.05) and MBP (P<0.05). Baicalein treatment also inhibited the cuprizone-induced increase in Iba1-positive microglia (P<0.001), GFAP-positive astrocytes (P<0.001), and the gene expressions of CD11b (P<0.01), GFAP (P<0.05), TNFα (P<0.05), IL-1β (P<0.05), and iNOS (p<0.01). We found that Baicalein treatment attenuated cuprizone-induced demyelination, glial activation, pro-inflammatory cytokine expression, and motor dysfunction. Our results suggest that Baicalein may be a useful therapeutic agent in demyelinating diseases to suppress neuroinflammation.

Astilbin alleviates sepsis-induced acute lung injury by inhibiting the expression of macrophage inhibitory factor in rats

Sepsis is a systemic inflammatory response syndrome caused by severe infections. Astilbin is a dihydroflavonol derivative found in many medicinal and food plants with multiple pharmacological functions. To investigate the effects of astilbin on sepsis-induced acute lung injury (ALI), cecal ligation and puncture was performed on rats to establish a sepsis-induced ALI model; these rats were then treated with astilbin at different concentrations. Lung injury scores, including lung wet/dry ratio, protein leakage, myeloperoxidase activity, and inflammatory cell infiltration were determined to evaluate the effects of astilbin on sepsis-induced ALI. We found that astilbin treatment significantly attenuates sepsis-induced lung injury and improves survival rate, lung injury scores, lung wet/dry ratio, protein leakage, myeloperoxidase activity, and inflammatory cell infiltration. Astilbin treatment also dramatically decreased the production of inflammatory cytokines and chemokines in bronchoalveolar lavage fluid. Further, astilbin treatment inhibited the expression and production of macrophage inhibitory factor (MIF), which inhibits the inflammatory response. Collectively, these data suggest that astilbin has a protective effect against sepsis-induced ALI by inhibiting MIF-mediated inflammatory responses. This study provides a molecular basis for astilbin as a new medical treatment for sepsis-induced ALI.

Reciprocal cooperation of phytochemicals and micronutrients against typical and atypical forms of Borrelia sp

AIMS

Borrelia sp., a causative pathogenic factor of Lyme disease (LD), has become a major public health threat. Current treatments based on antibiotics often lead to relapse after their withdrawal. Naturally derived substances that could work synergistically to display higher efficacy compared with the individual components may serve as a resource for the development of novel approaches to combat both active and latent forms of Borrelia sp.

METHODS AND RESULTS

Using checkerboard assay, we investigated the anti-borreliae reciprocal cooperation of phytochemicals and micronutrients against two species of Borrelia selected as prevalent causes of LD in the United States and Europe. We tested 28 combinations of phytochemicals such as polyphenols (baicalein, luteolin, rosmarinic acids), fatty acids (monolaurin, cis-2-decenoic acid) and micronutrients (ascorbic acid, cholecalciferol and iodine). The results showed that the combinations of baicalein with luteolin as well as monolaurin with cis-2-decenoic acid expressed synergistic anti-spirochetal effects. Moreover, baicalein and luteolin, when combined with rosmarinic acid or iodine, produced additive bacteriostatic and bactericidal effects against typical corkscrew motile spirochaetes and persistent knob/round-shaped forms, respectively. An additive anti-biofilm effect was noticed between baicalein with luteolin and monolaurin with cis-2-decenoic acid. Finally, application of the combination of baicalein with luteolin increased cytoplasmic permeability of Borrelia sp. but did not cause DNA damage.

CONCLUSIONS

These results show that a specific combination of flavones might play a supporting role in combating Borrelia sp. through either synergistic or additive anti-borreliae effects.

SIGNIFICANCE AND IMPACT OF THE STUDY

Presented here in vitro results might help advancing our knowledge and improving the approach to target Borrelia sp.

Baicalein Attenuates Lung Injury Induced by Myocardial Ischemia and Reperfusion

Baicalein is an active component of Scutellaria baicalensis Georgi, which has traditionally been used to treat cardiovascular diseases in China. In this study, we investigated if treatment with baicalein can attenuate the lung injury induced by myocardial ischemia and reperfusion (I/R). Myocardial I/R, induced by a 40-min occlusion of the left anterior descending coronary artery and a 3-h reperfusion, significantly increased histological damage and the wet-to-dry weight ratio of lungs in rats. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive nuclei and caspase-3 activation was significantly increased in the lungs. Serum and bronchoalveolar lavage fluid levels of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]), interleukin-1[Formula: see text] (IL-1[Formula: see text]), and interleukin-6 (IL-6) were significantly elevated, as were TNF-[Formula: see text] levels in the lung. Intravenous administration with baicalein at doses of 3, 10, and 30[Formula: see text]mg/kg for ten minutes before myocardial I/R significantly reduced histological damage, the wet-to-dry weight ratio, and apoptosis in the lung. Baicalein also significantly inhibited the increase in levels of TNF-[Formula: see text], IL-1[Formula: see text], and IL-6. Moreover, baicalein increased Bcl-2 and decreased p53, Bax, and cytochrome [Formula: see text] in lungs. Phosphorylation of the prosurvival kinases, including Akt and extracellular signal-regulated kinases 1 and 2 (ERK1/2), was increased, while the phosphorylation of the pro-apoptotic mitogen-activated protein kinases, including p38 and c-Jun N-terminal kinase (JNK), was decreased. In conclusion, treatment with baicalein attenuates the lung injury induced by myocardial I/R. The mechanisms might be related to the limiting of apoptosis, possibly via the inhibition of both the extrinsic and intrinsic pathways of apoptosis, including the inhibition of TNF-[Formula: see text] production and modulation of pro- and anti-apoptotic signaling elements.

The Role of Biologically Active Ingredients from Natural Drug Treatments for Arrhythmias in Different Mechanisms

Arrhythmia is a disease that is caused by abnormal electrical activity in the heart rate or rhythm. It is the major cause of cardiovascular morbidity and mortality. Although several antiarrhythmic drugs have been used in clinic for decades, their application is often limited by their adverse effects. As a result, natural drugs, which have fewer side effects, are now being used to treat arrhythmias. We searched for all articles on the role of biologically active ingredients from natural drug treatments for arrhythmias in different mechanisms in PubMed. This study reviews 19 natural drug therapies, with 18 active ingredient therapies, such as alkaloids, flavonoids, saponins, quinones, and terpenes, and two kinds of traditional Chinese medicine compound (Wenxin-Keli and Shensongyangxin), all of which have been studied and reported as having antiarrhythmic effects. The primary focus is the proposed antiarrhythmic mechanism of each natural drug agent. Conclusion. We stress persistent vigilance on the part of the provider in discussing the use of natural drug agents to provide a solid theoretical foundation for further research on antiarrhythmia drugs.

Analgesia effect of baicalein against NTG-induced migraine in rats

BACKGROUND

Migraine is a complex nervous system disease characterized by typical throbbing and unilateral headache, which causes severe healthy and social issues worldwide. The purpose of this study was to investigate the effect of baicalein (BAI) on the treatment of migraine.

MATERIAL AND METHODS

Twenty-four rats were randomly divided equally into four groups, including a blank group, model group, positive group (ibuprofen tablets 82mg/kg), and BAI group (60mg/kg). All rats were intragastrically treated with the corresponding treatment for 10 consecutive days, and they were subcutaneously injected with NTG (10mg/kg) 1h after the last treatment, except in the blank group. After model establishment, the behaviors of all rats, including scratching head and shaking body were observed continuously for 100min. Four hours after NTG treatment, all rats were anaesthetized and the blood was collected. Thereafter, nitric oxide (NO) in plasma was determined by colorimetric method, the level of calcitonin gene-related peptide (CGRP) and endothelin (ET) were detected by radioimmunoassay method. In addition, immunohistochemistry was applied to detect c-Fos neuronal activity in trigeminal nucleus caudalis (TNC).

RESULTS

Behavioral research showed that BAI administration alleviated the hyperalgesia in migraine rats. Compared with the model group, the levels of NO and CGRP in BAI administration groups were markedly decreased (p<0.01), and the levels of ET was significantly increased (p<0.01). Meanwhile, immunohistochemistry results showed that NTG treatment significantly activated c-Fos neurons while BAI treatment inhibited the expression of c-Fos.

CONCLUSIONS

BAI could alleviate the migraine-like headache induced by NTG, which is related to the regulation of vasoactive substances. These findings may contribute to the further study of BAI as a potential drug for migraine pharmacotherapy.

Therapeutic potentials of baicalin and its aglycone, baicalein against inflammatory disorders

The flavonoids, baicalin (5,6-dihydroxy-2-phenyl-4H-1-benzopyran-4-one-7-O-d-β-glucuronic acid) 1 and its aglycone, baicalein 2 are found in edible medicinal plants, Scutellaria baicalensis Georgi and Oroxylum indicum (L.) Kurz in abundant quantities. The antioxidant and anti-inflammatory effects of these flavonoids have been demonstrated in various disease models, including diabetes, cardiovascular diseases, inflammatory bowel diseases, gout and rheumatoid arthritis, asthma, neurodegenerative-, liver- and kidney diseases, encephalomyelitis, and carcinogenesis. These flavonoids have almost no toxicity to human normal epithelial, peripheral and myeloid cells. Their antioxidant and anti-inflammatory activities are largely due to their abilities to scavenge the reactive oxygen species (ROS) and improvement of antioxidant status by attenuating the activity of NF-κB and suppressing the expression of several inflammatory cytokines and chemokines including monocyte chemotactic protein-1 (MCP-1), nitric oxide synthase, cyclooxygenases, lipoxygenases, cellular adhesion molecules, tumor necrosis factor and interleukins. In this review, we summarize the antioxidant and anti-inflammatory effects of baicalin and baicalein with molecular mechanisms for their chemopreventive and chemotherapeutic applications in the treatment of inflammatory-related diseases.

LPS-induced renal inflammation is prevented by (-)-epicatechin in rats

This work investigated the capacity of (−)-epicatechin to prevent the renal damage induced by LPS administration in rats. Male Sprague Dawley rats were fed for 4 days a diet without or with supplementation with (−)-epicatechin (80 mg/kg BW/d), and subsequently i.p. injected with lipopolysaccharide (LPS). Six hours after injection, LPS-treated rats exhibited increased plasma creatinine and urea levels as indicators of impaired renal function. The renal cortex of the LPS-treated rats showed: i) increased expression of inflammatory molecules (TNF-α, iNOS and IL-6); ii) activation of several steps of NF-κB pathway; iii) overexpression of TLR4, and iv) higher superoxide anion production and lipid peroxidation index in association with increased levels of gp91^phox and p47^phox (NOX2) and NOX4. Pretreatment with dietary (−)-epicatechin prevented the adverse effects of LPS challenge essentially by inhibiting TLR4 upregulation and NOX activation and the consequent downstream events, e.g. NF-kB activation.

Anti-Inflammatory Effects of Liriope platyphylla in LPS-Stimulated Macrophages and Endotoxemic Mice

In the present study, the anti-inflammatory and antisepticemic activities of a water extract of Liriope platyphylla (LP) were investigated. We first estimated the scavenging activity of DPPH and the hydroxyl radical and total phenolic contents of LP. Results indicated that LP, a rich source of phenolic compounds, showed a remarkable radical scavenging capacity. A MTT assay showed that LP treatment did not affect the toxicity against the RAW 264.7 macrophage cells, up to the concentration of 500[Formula: see text][Formula: see text]g/mL. Treatment of LP significantly attenuated the production of inflammatory mediators, such as nitric oxide (NO), interleukin-6 (IL-6), tumor-necrosis factor (TNF)-[Formula: see text] and prostaglandin (PG)E2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages cells. Moreover, LP contributed to the down-regulation of inducible NO synthase (iNOS) and TNF-[Formula: see text] mRNA expression, as well as cyclooxygenase-2 (COX-2) protein expression. A western blotting assay further showed that LP inhibited activation of mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-[Formula: see text]B. In an animal experiment using an LPS-induced septicemia model in C57BL/6 mice, oral administration of LP (40[Formula: see text]mg/kg body weight) markedly reduced the level of TNF-[Formula: see text] and IL-6 in serum and protected against LPS-induced lethal shock in mice. Taken together, the results of treatments of LP on inhibited LPS-induced inflammatory responses in both in vitro and in vivo models and indicate it may be a promising neutraceutical or medicinal agent to prevent or cure inflammation-related disease.

Induction of endothelium-dependent constriction of mesenteric arteries in endotoxemic hypotensive shock

BACKGROUND AND PURPOSE

Effective management of hypotension refractory to vasoconstrictors in severe sepsis is limited. A new strategy to ameliorate endotoxemic hypotension by inducing endothelium-dependent constriction of large arteries was assessed.

EXPERIMENTAL APPROACH

Endotoxemia in rats was induced by injection of LPS (10 mg·kg(-1), i.v.). Haemodynamics were measured in vivo, reactivity of isolated mesenteric arteries by myography and expression of proteins and enzyme activities by immunohistochemistry, biochemistry and molecular biology.

KEY RESULTS

Six hours after LPS, the hypotension was promptly reversed following injection (i.v. or i.p.) of oroxylin-A (OroA) . In isolated LPS-treated but not normal mesenteric arteries, OroA (1-10 μM) induced endothelium-dependent, sustained constriction, blocked by endothelin-1 (ET-1) receptor antagonists. OroA further enhanced LPS-induced expression of endothelin-converting enzyme, ET-1 mRNA and proteins and ET-1 release, OroA also enhanced phosphorylation of Rho-associated protein kinase (ROCK) and reversed LPS-induced suppression of RhoA activities in smooth muscle of arteries with endothelium. Activated- phosphorylation of smooth muscle ROCK was blocked by ET-1-receptor antagonists and ROCK inhibitors. Moreover, OroA post-treatment suppressed, via inhibiting NF-κB activation, inducible NOS expression and circulating NO.

CONCLUSIONS AND IMPLICATIONS

Reversal of endotoxemic hypotensive by OroA was due to release of endothelial ET-1, upregulated by LPS, from mesenteric arteries, inducing prompt and sustained vasoconstriction via activation of vascular smooth muscle RhoA/ROCK-pathway. In late endotoxemia, OroA-induced vasoconstriction was partly due to decreased circulating NO. Activation of endothelium-dependent constriction in large resistance arteries and suppression of systemic inflammation offer new strategies for acute management of endotoxemic hypotensive shock.

Alpha-lipoic acid prevents endotoxic shock and multiple organ dysfunction syndrome induced by endotoxemia in rats

Alpha-lipoic acid (ALA), a naturally occurring disulfide derivative of octanoic acid, serves as a strong antioxidant and has been reported to possess anti-inflammatory effects. The aim of the present study is to investigate the preventive and therapeutic effects of ALA on multiple organ dysfunction syndrome (MODS) caused by endotoxemia in rats. Male Wistar rats were intravenously infused with lipopolysaccharide (LPS) (10 mg/kg) to induce endotoxemia. Alpha-lipoic acid 10, 20, or 40 mg/kg was administered intravenously 60 min before (pretreatment) LPS challenge, and ALA 40 mg/kg was administered intravenously 30 min after (posttreatment) LPS challenge. Pretreatment and posttreatment with ALA significantly improved the deleterious hemodynamic changes 8 h after LPS challenge, including hypotension and bradycardia. Alpha-lipoic acid reduced the plasma levels of glutamic pyruvic transaminase, blood urea nitrogen, lactate dehydrogenase, tumor necrosis factor-α, nitric oxide metabolites, and thrombin-antithrombin complex, which increased markedly after LPS challenge. The induction of inducible nitric oxide synthase both in the liver and the lung and vascular superoxide anion production were also significantly suppressed by ALA. Moreover, ALA significantly attenuated LPS-induced caspase-3 activation in cardiomyocytes and improved survival rate. In conclusion, ALA effectively attenuated LPS-induced acute inflammatory response and improved MODS. The antioxidant and anti-inflammatory effects of ALA may contribute to these beneficial effects. Alpha-lipoic acid might be considered as a novel therapeutic strategy in the prevention of sepsis-induced MODS and inflammatory vascular diseases.

Eriodictyol, a plant flavonoid, attenuates LPS-induced acute lung injury through its antioxidative and anti-inflammatory activity

Acute lung injury (ALI) is characterized by excessive inflammatory responses and oxidative injury in the lung tissue. It has been suggested that anti-inflammatory or antioxidative agents could have therapeutic effects in ALI, and eriodictyol has been reported to exhibit antioxidative and anti-inflammatory activity in vitro. The aim of the present study was to investigate the effect of eriodictyol on lipopolysaccharide (LPS)-induced ALI in a mouse model. The mice were divided into four groups: Phosphate-buffered saline-treated healthy control, LPS-induced ALI, vehicle-treated ALI (LPS + vehicle) and eriodictyol-treated ALI (LPS + eriodictyol). Eriodictyol (30 mg/kg) was administered orally once, 2 days before the induction of ALI. The data showed that eriodictyol pretreatment attenuated LPS-induced ALI through its antioxidative and anti-inflammatory activity. Furthermore, the eriodictyol pretreatment activated the nuclear factor erythroid-2-related factor 2 (Nrf2) pathway in the ALI mouse model, which attenuated the oxidative injury and inhibited the inflammatory cytokine expression in macrophages. In combination, the results of the present study demonstrated that eriodictyol could alleviate the LPS-induced lung injury in mice by regulating the Nrf2 pathway and inhibiting the expression of inflammatory cytokines in macrophages, suggesting that eriodictyol could be used as a potential drug for the treatment of LPS-induced lung injury.

Quantitative analysis and anti-inflammatory effects of Gleditsia sinensis thorns in RAW 264.7 macrophages and HaCaT keratinocytes

Gleditsia sinensis thorns have traditionally been used to treat edema and carbuncles and drain abscesses. In the present study, a simultaneous analysis of four flavonoids [(+)‑catechin, (‑)‑epicatechin, eriodictyol and quercetin] and two phenolic compounds (caffeic acid and ethyl gallate), obtained from a 70% ethanol extract of G. sinensis, was performed using high‑performance liquid chromatography‑photodiode array techniques. In addition, the inhibitory activities of the solvent fractions from a G. sinensis extract and its major constituents on the lipopolysaccharide‑stimulated production of inflammatory mediators by macrophage RAW 264.7 cells and the tumor necrosis factor (TNF)‑α and interferon (IFN)‑γ (TI)‑stimulated production of chemokines by HaCaT keratinocyte cells were investigated. The established analytical method showed high linearity, with a correlation coefficient of ≥0.9998. The limits of detection and quantification of the six compounds were 0.037‑0.425 and 0.124‑1.418 µg/ml, respectively. The ethyl acetate fraction inhibited nitric oxide and prostaglandin E2 production in RAW 264.7 cells and the production of thymus‑ and activation‑regulated chemokine (TARC) in HaCaT cells more than did the other fractions. Furthermore, the six compounds reduced the production of TARC, macrophage‑derived chemokine and regulated on activation normal T‑cell expressed and secreted in TI‑stimulated HaCaT cells; in particular, ethyl gallate and quercetin exhibited a significant dose‑dependent inhibition. Further elucidation of the signaling pathways involved in the T‑helper cell 2 chemokine inhibition by G. sinensis is necessary to facilitate the design of therapeutic agents for the inflammatory response.

Baicalein reduces the occurrence of cirrhotic endotoxemia by reducing intestinal mucosal apoptosis

BACKGROUND

The dried roots of Scutellaria baicalensis Georgi, is known in traditional Chinese medicine as Huang Qin (H. qin), and it has been officially and traditionally used in treatment of various diseases such as hepatitis in China. Baicalein (BA), a flavonoid originally isolated from H. qin, has shown a wide range of biological activities. This study was to evaluate whether baicalein, can reduce the intestinal mucosal cell apoptosis caused by cirrhotic endotoxemia and its possible mechanisms.

METHODS

For this purpose, compound factors modeling was used to establish endotoxemic cirrhotic rat model. Firstly, we evaluated endotoxin, ALT, AST and TBIL levels after the baicalein treatment (20 mg/kg, i.v.). To investigate the mechanism of baicalein effect on apoptosis, TUNEL assay was used to detect intestinal mucosal apoptosis. RT-PCR was used to detect the expression levels of gene Bcl-2 mRNA and Bax mRNA in intestinal mucosal tissues. Caspase-3 activity of intestinal tissue was detected with colorimetric method in our experiments.

RESULTS

After treatment with BA, the serum endotoxin concentration, the intestinal mucosal apoptosis rate and the activity of caspase-3 of the baicalein group were significantly lower than that of the model and the glutamine group. The serum ALT, AST and TBIL concentration of the BA group were significantly lower than that of the model group. The body weight of the baicalein group was significantly lower than that of the normal group, but it was higher than that of the model group. Among the treatment groups, the mRNA level of anti-apoptotic gene Bcl-2 was the lowest in the model group and the highest in the baicalein group while the mRNA level of pro-apoptotic gene Bax was the lowest in the baicalein group and the highest in the model group.

CONCLUSION

The present results demonstrated that baicalein could reduce the occurrence of cirrhotic endotoxemia partly by reducing intestinal mucosal apoptosis.

Inhibition of MAP kinase/NF-kB mediated signaling and attenuation of lipopolysaccharide induced severe sepsis by cerium oxide nanoparticles

Sepsis is a life threatening disease that is associated with high mortality. Existing treatments have failed to improve survivability in septic patients. The purpose of this present study is to evaluate whether cerium oxide nanoparticles (CeO2NPs) can prevent lipopolysaccharide (LPS) induced severe sepsis mortality by preventing hepatic dysfunction in male Sprague Dawley rats. Administration of a single dose (0.5 mg/kg) of CeO2NPs intravenously to septic rats significantly improved survival rates and functioned to restore body temperature, respiratory rate and blood pressure towards baseline. Treatment-induced increases in animal survivability were associated with decreased hepatic damage along with reductions in serum cytokines/chemokines, and diminished inflammatory related signaling. Kupffer cells and macrophage cells exposed to CeO2NPs exhibited decreases in LPS-induced cytokine release (TNF-α, IL-1β, IL-6, HMGB1) which were associated with diminished cellular ROS, reduced levels of nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and decreased nuclear factor-kappa light chain enhancer of activated B cells (NF-kB) transcriptional activity. The findings of this study indicate that CeO2NPs may be useful as a therapeutic agent for sepsis.

Effect of cerium oxide nanoparticles on sepsis induced mortality and NF-κB signaling in cultured macrophages

Aim: To investigate whether cerium oxide (CeO2) nanoparticles could be used for the treatment of severe sepsis. Materials & methods: Cecal peritonitis was induced in male Sprague–Dawley rats in the presence and absence of CeO2 nanoparticles. Cultured macrophages (RAW264.7 cells) were challenged with lipopolysaccharide in the absence and presence of CeO2 nanoparticles. The effect of nanoparticles on the growth of Escherichia coli and Staphylococcus aureus was determined in culture. Results: Nanoparticle treatment decreased sepsis-induced mortality, organ damage, serum IL-6, blood urea nitrogen and inflammatory markers. Nanoparticle treatment diminished lipopolysaccharide-induced cytokine release and p65-nuclear factor-KB (NF-KB) activation in cultured RAW264.7 cells. Exposure to CeO2 nanoparticles inhibited E. coli growth. Conclusion: The findings of this study indicate that CeO2 nanoparticles may be useful for the treatment of sepsis.

Baicalein protects against polymicrobial sepsis-induced liver injury via inhibition of inflammation and apoptosis in mice

Liver dysfunction has been known to occur frequently in cases of sepsis. Baicalein, the main active ingredient of the Scutellaria root, exerts anti-inflammatory and anti-apoptotic properties in endotoxic shock. However, the role of baicalein in polymicrobial sepsis-induced liver injury and its regulatory mechanisms remain unclear. In this study, we aimed to investigate the protective effects of baicalein on polymicrobial sepsis-induced liver injury and to explore the possible mechanisms. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) in C57BL/6 mice. Mice were treated with baicalein (100mg/kg, i.p) at 1h, 6h and 12h following CLP. Baicalein significantly improved the survival of septic mice. Treatment with baicalein ameliorated the CLP-induced liver injury, as indicated by the lower serum aminotransferase levels and the fewer histopathologic abnormalities. Baicalein reduced the neutrophil infiltration and the hepatic inflammatory cytokine expression and release. It also decreased the hepatic and the serum high-mobility group box 1 and macrophage migration inhibitory factor levels in septic mice. Moreover, baicalein significantly inhibited the mitogen-activated protein kinases (MAPKs) activation and suppressed the transcriptional activity of nuclear factor-kappa B (NF-κB). In conclusion, these results suggest that baicalein treatment could protect against the sepsis-induced liver injury, and improve the survival of mice with polymicrobial sepsis. The mechanism of the protective action of baicalein seems to involve its ability to reduce inflammatory response, to inhibit hepatic apoptosis, and to suppress MAPKs and NF-κB activation.

Baicalein protects against hypertension associated with diabetes: effect on vascular reactivity and stiffness

The present work investigated the possible protective effect of baicalein, a natural lipoxygenase enzyme inhibitor, on both insulin deficiency (ID) and insulin resistance (IR)-induced macro-vascular impairment. ID and IR were induced by STZ or fructose for 8 or 12 weeks respectively while baicalein was administered in the last six weeks. Blood pressure (BP) was recorded and isolated aorta reactivity to phenylephrine (PE) and acetylcholine (ACh) were studied. Blood levels of glucose, insulin, advanced glycation end products (AGEs) and tumour necrosis factor-α (TNF-α) were determined. Aortic nuclear transcription factor-κB (NF-κB) activation was assessed. Both models resulted in elevated BP, increased vasoconstriction and impaired relaxation KCl, elevated TNF-α and AGEs, NF-κB activation, marked infiltration of leukocytes in the adventitia, pyknosis of endothelial cells and marked collagen deposition. Baicalein ameliorated elevations in BP in models, prevented exaggerated vasoconstriction IR model and improved relaxation in ID model. Baicalein reduced AGEs and TNF-α level, decreased NF-κB activation and inhibited histopathological changes in both models. Baicalein offsets the hypertensive and the vascular impairment associated with both diabetic models via ameliorating functional and structural derangements of blood vessels.

Flavocoxid, a nutraceutical approach to blunt inflammatory conditions

Flavonoids, from Scutellaria baicalensis (Chinese skullcap) and Acacia catechu (black catechu), have been shown to exert a variety of therapeutic effects, including anti-inflammatory, antiviral, antibacterial, and anticancer activities. Flavocoxid is a mixed extract containing baicalin and catechin and it acts as a dual balanced inhibitor of cyclooxygenase-1 (COX-1) and COX-2 peroxidase enzyme activities with a significant inhibition of 5-lipoxygenase (5-LOX) enzyme activity in vitro. Flavocoxid downregulates gene or protein expression of several inflammatory markers and exerts also strong antioxidant activity in several experimental models. Controlled clinical trials and a postmarketing study have clearly shown that flavocoxid is as effective as naproxen in managing the signs and symptoms of osteoarthritis of the knee and it has better upper gastrointestinal, renal, and respiratory safety profile than naproxen. Flavocoxid may therefore provide a potential therapeutic approach to the treatment of chronic inflammatory conditions.

Anti-inflammatory activity of baicalein in LPS-stimulated RAW264.7 macrophages via estrogen receptor and NF-κB-dependent pathways

Baicalein has been used for many years as a popular antiviral and antibacterial in China. Recent investigations revealed that baicalein also has anti-inflammatory activities. Our results indicated that baicalein increases ERE-luciferase activity in an estrogen receptor (ER)-dependent manner when either ERα or ERβ were coexpressed in Hela cells. This study examined whether baicalein exerts an anti-inflammatory effect in RAW264.7 cells through an estrogen receptor-dependent pathway and through regulation of NF-ĸB activation. In lipopolysaccharide (LPS)-induced RAW264.7 cells, baicalein exerts anti-inflammatory effects by inhibiting iNOS, COX-2, and TNF-α mRNA expression; NO production; as well as inflammatory cytokine (IL-1β, PGE2, and TNF-α) production through an ER-dependent pathway. These effects are accompanied with the inhibition of the transcription factor NF-ĸB activation and IκBα phosphorylation. We therefore conclude that baicalein inhibits LPS-induced inflammatory cytokine production via regulation of the NF-ĸB pathway and estrogen-like activity, suggesting that it may be useful for preventing inflammation-related diseases.