Euscaphic acid isolated from roots of Rosa rugosa inhibits LPS-induced inflammatory responses via TLR4-mediated NF-κB inactivation in RAW 264.7 macrophages

Neuroprotective Effects of Metformin and Berberine in Lipopolysaccharide-Induced Sickness-Like Behaviour in Mice

Sickness behaviour, a set of behavioural changes associated with neuroinflammation, is expressed as decreased mobility and depressed behaviour. Activation of AMP-activated protein kinase (AMPK) is reported to regulate inflammation in conditions such as Alzheimer and traumatic brain injury. Metformin, an antidiabetic agent acting via AMPK activation, possesses anti-inflammatory properties. Similarly, the reported anti-inflammatory activities of berberine could be partially attributed to its ability to activate AMPK. In this study, we investigated the effects of metformin and berberine against lipopolysaccharide (LPS)-induced sickness-like behaviour, associated with neuroinflammation, impaired cognition, and oxidative stress. Swiss albino mice were divided into four groups, normal control, LPS control, metformin treatment, and berberine treatment. The control groups received saline for 7 days. Groups 3 and 4 received metformin (200 mg/kg) and berberine (100 mg/kg), respectively, orally once daily for 7 days. On day 7, 1 h after the treatments, animals received LPS (1.5 mg/kg i.p.) to induce sickness-like behaviour. Open field test (OFT) and forced swim test (FST), were performed within 2 h of LPS administration. Then, proinflammatory cytokines (IL-1β and TNF-α), acetylcholinesterase activity (AChE), and oxidative stress markers were estimated in the brain homogenate. In the LPS control group, immobility state, proinflammatory cytokines, AChE, and lipid peroxidation were significantly increased, whereas the glutathione levels were decreased. Pretreatment with metformin significantly improved immobility in the FST, with reduced IL-1β, oxidative stress markers, and AChE activity. However, no significant changes were observed in OFT. Berberine pretreatment exhibited only an apparent, statistically insignificant, improvement in sickness-like behaviour assessed using FST and OFT, cytokine levels, oxidative markers, and AChE. Several factors affect treatment efficacy, such as treatment duration and administered dose. Considering these, berberine warrants elaborate preclinical evaluation for neuroinflammation. Nevertheless, based on the effects observed, AMPK activators could regulate neuroinflammation, cognition, and oxidative stress linked with sickness-like behaviour.

Dietary (Poly)phenols and the Gut-Brain Axis in Ageing

As the population ages, the incidence of age-related neurodegenerative diseases is rapidly increasing, and novel approaches to mitigate this soaring prevalence are sorely needed. Recent studies have highlighted the importance of gut microbial homeostasis and its impact on brain functions, commonly referred to as the gut-brain axis, in maintaining overall health and wellbeing. Nonetheless, the mechanisms by which this system acts remains poorly defined. In this review, we will explore how (poly)phenols, a class of natural compounds found in many plant-based foods and beverages, can modulate the gut-brain axis, and thereby promote neural health. While evidence indicates a beneficial role of (poly)phenol consumption as part of a balanced diet, human studies are scarce and mechanistic insight is still lacking. In this regard, we make the case that dietary (poly)phenols should be further explored to establish their therapeutic efficacy on brain health through modulation of the gut-brain axis, with much greater emphasis on carefully designed human interventions.

Euscaphic acid relieves fatigue by enhancing anti-oxidative and anti-inflammatory effects

BACKGROUND

Oxidative stress and inflammation are involved in chronic fatigue. Euscaphic acid (EA) is an active compound of Eriobotrya japonica (Loquat) and has anti-oxidative effect.

METHODS

The goal of present study is to prove whether EA could relieve fatigue through enhancing anti-oxidant and anti-inflammatory effects in in vitro/in vivo models.

RESULTS

EA notably improved activity of superoxide dismutase (SOD) and catalase (CAT), while EA reduced levels of malondiadehyde (MDA) and inflammatory cytokines without cytotoxicity in H₂O₂-stimulated in myoblast cell line, C2C12 cells. EA significantly reduced levels of fatigue-causing factors such as lactate dehydrogenase (LDH) and creatin kinase (CK), while EA significantly incresed levels of anti-fatigue-related factor, glycogen compared to the H₂O₂-stimulated C2C12 cells. In treadmill stress test (TST), EA significantly enhanced activities of SOD and CAT as well as exhaustive time and decreased levels of MDA and inflammatory cytokines. After TST, levels of free fatty acid, citrate synthase, and muscle glycogen were notably enhanced by oral administration of EA, but EA decreased levels of lactate, LDH, cortisol, aspartate aminotransferase, alanine transaminase, CK, glucose, and blood urea nitrogen compared to the control group. Furthermore, in forced swimming test, EA significantly increased levels of anti-fatigue-related factors and decreased excessive accumulations of fatigue-causing factors.

CONCLUSIONS

Therefore, the results indicate that potent anti-fatigue effect of EA can be achieved via the improvement of anti-oxidative and anti-inflammatory properties, and this study will provide scientific data for EA to be developed as a novel and efficient component in anti-fatigue health functional food.

Elsholtzia: A genus with antibacterial, antiviral, and anti-inflammatory advantages

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Elsholtzia (family Labiaceae) is an important source of folk traditional Chinese medicine, mainly used to relieve the symptoms of cold, fever, pneumonia and so on. However, currently available data on its traditional and pharmacological advantages have not been comprehensively reviewed.

AIM OF THE REVIEW

This review provides up-to-date and comprehensive information on the ethnopharmacological, phytochemical, pharmacological properties and toxicity of Elsholtzia, highlights the antibacterial, antiviral, and anti-inflammatory advantages of the genus, and explores its therapeutic potential.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the research literatures on application, chemistry and biological activity of Elsholtzia published before December 2021. Their scientific names have been verified using The Plant List and World Flora Online websites.

RESULTS

A total of 42 species of Elsholtzia are widely distributed all over the world, especially in Yunnan Province (China). Since Elsholtzia genus is commonly used in the folk to treat respiratory infectious diseases such as cold and fever, growing numbers of studies have confirmed their antiviral, antibacterial and anti-inflammatory activities. So far, about 221 non-volatile compounds and 1008 volatile compounds have been identified from Elsholtzia plants, mainly containing flavonoids and terpenoids showing convincing antibacterial, antiviral and anti-inflammatory activities. Further research found that their antibacterial and antiviral spectrums are broad, and volatile oils are considered to be the main antibacterial components. Their anti-inflammatory mechanism is mainly through the inhibition of NF-κB and MAPKs signaling pathways. Toxicological studies have not established its toxicity.

CONCLUSIONS

By summarizing the latest information on genus Elsholtzia, their traditional uses, material basis and mechanisms of action in antiviral, antibacterial and anti-inflammatory aspects were described, providing new insights for the genus and its importance as a potential natural resource of antiviral and anti-inflammatory drugs, giving evidence and new ideas for the development of herbal medicines.

Putative involvement of sirtuin modulators in LPS-induced sickness behaviour in mice

NAD⁺-dependent histone deacetylases (sirtuins 1-7) have been shown to be involved in various pathophysiological conditions including their involvement in cardiovascular, cancerous, neurodegenerative, immune dysregulation and inflammatory conditions. This study investigates the inflammomodulatory potential of resveratrol (RES), a sirtuin activator and sirtinol (SIR), a sirtuin inhibitor in lipopolysaccharide (LPS)-induced model of sickness behaviour in mice. Male Swiss albino mice were divided into five groups (n = 6) consisting of saline (SAL), LPS, RES, SIR, and fluoxetine (FLU) respectively, each group except LPS was prepared by intraperitoneally (i.p.) administration of SAL (10 mL/kg), RES (50 mg/kg), SIR (2 mg/kg) and FLU (10 mg/kg). Thirty minutes after the treatments, all the groups, except SAL were administered LPS (2 mg/kg, i.p.). The behavioural assays including, open field test, forced swim test, and tail suspension tests were conducted 1 h after LPS challenge. LPS administration significantly reduced the locomotor activity along with inducing a state of high immobility and that was prevented by pretreatment with RES and SIR. Further, various proinflammatory cytokines (TNF-α, IL-6, and IL-1β), and oxidative stress markers (MDA and GSH) were found to be significantly elevated in the brain homogenates after LPS treatment. SIR pretreatment abrogated the LPS-induced neuroinflammatory and oxidative stress changes, whereas RES was only effective in reducing the oxidative stress and TNF-α levels. The results of this study speculate that the role of SIRT modulators in neuroinflammatory conditions could vary with their dose, regimen and chemical properties. Further studies with detailed molecular and pharmacokinetic profiling will be needed to explore their therapeutic potentials.

Inhibitory Effects of Euscaphic Acid in the Atopic Dermatitis Model by Reducing Skin Inflammation and Intense Pruritus

Atopic dermatitis (AD) is a complex and multifactorial skin disease characterized by skin inflammation and intense pruritus. There are many commercially available treatments such as topical corticosteroids and immunosuppressants to treat of AD, but their effectiveness is limited, and frequent use of these treatments can cause serious side effects. Therefore, the development of new therapeutic agents is necessary for the treatment of AD. Hence, an alternative agent that was derived from natural products that are effective and safe for AD treatment was investigated using experimental models. The biological activity of euscaphic acid has anti-inflammatory, anticoagulant, and antioxidant effects. Despite the various biomedical properties of euscaphic acid, its therapeutic effects on AD have not been well studied. In this study, we investigated the effects of euscaphic acid on skin inflammation and pruritus in AD mouse model. The effects of euscaphic acid were investigated in activated human epidermal keratinocytes and leukemia T lymphoblast cell lines, and Dermatophagoides farina extract and 2,4-dinitrochlorobenzene-induced AD mouse model. Euscaphic acid ameliorated AD properties, such as the expression of inflammatory cytokines and activation of transcription factors. In addition, euscaphic acid reduced critical factors for pruritus such as immunoglobulin E hyperproduction, mast cell invasion, and interleukin-33 expression. Taken together, euscaphic acid could be a potent therapeutic agent for the treatment of AD.

Network pharmacology analysis to explore mechanism of three flower tea against nonalcoholic fatty liver disease with experimental support using high-fat diet-induced rats

Objective

Nonalcoholic fatty liver disease (NAFLD) has become a common chronic liver disease that is harmful to human health. Moreover, there is currently no FDA-approved first-line drug for the treatment of nonalcoholic steatohepatitis (NASH) or NAFLD. Traditional Chinese medicine (TCM) is widely used to ameliorate liver diseases, such as the traditional ancient recipe called Three Flower Tea (TFT), which consists of double rose (Rosa rugosa), white chrysanthemum (Chrysanthemum morifolium), and Daidaihua (Citrus aurantium). However, the mechanisms of the action of TFT are not clear. Therefore, this study aimed to elucidate the mechanisms of TFT against NAFLD in high-fat diet (HFD)-induced rats.

Methods

This study utilized bioinformatics and network pharmacology to establish the active and potential ingredient-target networks of TFT. Furthermore, a protein–protein interaction (PPI) network was constructed, and enrichment analysis was performed to determine the key targets of TFT against NAFLD. Furthermore, an animal experiment was conducted to evaluate the therapeutic effect and confirm the key targets of TFT against NAFLD.

Results

A total of 576 NAFLD-related genes were searched in GeneCards, and under the screening criteria of oral bioavailability (OB) ≥30% and drug-likeness (DL) ≥0.18, a total of 19 active ingredients and 210 targets were identified in TFT. Network pharmacology analysis suggested that 55 matching targets in PPIs were closely associated with roles for NAFLD treatment. Through the evaluation of network topology parameters, four key central genes, PPARγ, SREBP, AKT, and RELA, were identified. Furthermore, animal experiments indicated that TFT could reduce plasma lipid profiles, hepatic lipid profiles and hepatic fat accumulation, improve liver function, suppress inflammatory factors, and reduce oxidative stress. Through immunoblotting and immunofluorescence analysis, PPARγ, SREBP, AKT, and RELA were confirmed as targets of TFT in HFD-induced rats.

Conclusion

In summary, our results indicate that TFT can prevent and treat NAFLD via multiple targets, including lipid accumulation, antioxidation, insulin sensitivity, and inflammation.

Spectrum-effect relationship between UPLC fingerprints and antidiabetic and antioxidant activities of Rosa rugosa

In this study, the antidiabetic and antioxidant properties of the chemical constituents of Rosa rugosa Thunb. (R. rugosa) was evaluated through analysis of spectrum-effect relationship. The ultra-performance liquid chromatography (UPLC) fingerprints of 21 batches of R. rugosa were evaluated by similarity analysis (SA) and hierarchical clustering analysis (HCA). The 28 common components were identified by ultra-high-performance liquid chromatography coupled to quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-orbitrap-HRMS/MS). Meanwhile, the antidiabetic activities and antioxidant activities of 21 batches of R. rugosa were estimated in vitro. Besides, four chemometrics named principal component analysis (PCA), grey correlation analysis (GRA), partial least squares regression (PLSR) and the bivariate correlations analysis (BCA) were applied to construct spectrum-effect relationship between the UPLC fingerprints and biological activities of R. rugosa. The spectrum-effect relationship study revealed that di-O-galloyl-HHDP-glucoside, galloyl-HHDP-glucoside and avicularin were more relevant to antidiabetic activity. Di-O-galloyl-HHDP-glucoside, galloyl-HHDP-glucoside and ellagic acid were the main antioxidant components of R. rugosa. The current bioassay and spectrum-effect relationships are proper for associating sample quality with the active ingredient, and our finding would provide foundation and further understanding of the quality evaluation and quality control of R. rugosa.

The Occurrence and Biological Activity of Tormentic Acid-A Review

This review focuses on the natural sources and pharmacological activity of tormentic acid (TA; 2α,3β,19α-trihydroxyurs-2-en-28-oic acid). The current knowledge of its occurrence in various plant species and families is summarized. Biological activity (e.g., anti-inflammatory, antidiabetic, antihyperlipidemic, hepatoprotective, cardioprotective, neuroprotective, anti-cancer, anti-osteoarthritic, antinociceptive, antioxidative, anti-melanogenic, cytotoxic, antimicrobial, and antiparasitic) confirmed in in vitro and in vivo studies is compiled and described. Biochemical mechanisms affected by TA are indicated. Moreover, issues related to the biotechnological methods of production, effective eluents, and TA derivatives are presented.

Octreotide and melatonin alleviate inflammasome-induced pyroptosis through inhibition of TLR4-NF-κB-NLRP3 pathway in hepatic ischemia/reperfusion injury

BACKGROUND AND AIM

The Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB)/NLRP3 inflammasome signaling pathway is essential in the pathogenesis of hepatic ischemia/ reperfusion (HIR) injury. Pyroptosis is a proinflammatory programmed cell death that is related to several diseases. Thus, the purpose of this study was to examine whether pretreatment with octreotide (somatostatin analogue, OCT) at different doses or OCT at 75μg/kg combined with melatonin (N-acetyl-5-methoxytryptamine, MLT) can alleviate HIR injury via targeting NLRP3 inflammasome-induced pyroptosis in a TLR4/MyD88/NF-κB dependent manner.

METHODS

Rats were randomized into sham, HIR, OCT (50, 75, and 100 µg/kg), MLT, and MLT + OCT75 groups. Ischemia was induced via occlusion of the portal triad for 30 min followed by 24 h reperfusion.

RESULTS

OCT pretreatment at doses (50 or 75 μg/kg), MLT alone, and MLT + OCT75 significantly ameliorated the biochemical with histopathological changes, oxidative stress, inflammation, apoptosis, then augmented anti-oxidant and anti-apoptotic markers through downregulation of HMGB1, TLR4, MyD88, TRAF-6, p-IκBα (S32), p-NF-κBp65 (S536), NLRP3, ASC, caspase-1(p20), and GSDMD-N expressions compared with HIR group.

CONCLUSION

OCT at doses (50 or 75 µg/kg) showed for the first time a hepatoprotective effect against HIR injury via inhibiting TLR4-NLRP3-mediated pyroptosis in rats. As well, OCT75 was more effective than OCT50 or MLT alone, and its effect was not enhanced after the addition of MLT, through downregulation of TLR4/MyD88/NF-κB/NLRP3 inflammasome pathway.

Sulforaphane mitigates LPS-induced neuroinflammation through modulation of Cezanne/NF-κB signalling

AIM

Neuroinflammation is a potent pathological process of various neurodegenerative diseases. Sulforaphane (SFN) is a natural product and acts as a neuroprotective agent to suppress inflammatory response in brain. The present study investigated the protective effect of Sulforaphane (SFN) on lipopolysaccharide (LPS)-induced neuroinflammation.

MATERIALS AND METHODS

Rats were divided into three groups: control group, LPS group and LPS + SFN group. Morris water maze test was carried out to evaluate the spatial memory and learning function of rats. The inflammatory cytokines levels in hippocampal tissues, plasma were measured by ELISA. The western blot was used to detect Cezanne/NF-κB signalling. For in vitro study, the Cezanne siRNA and scrambled control were transfected into BV2 cells, and then treated with or without 20 μM SFN before exposed to LPS. The inflammatory cytokines levels and Cezanne/NF-κB signalling were detected by ELISA and western blot, respectively. Co-IP assay were applied to investigate the regulation of Cezanne on ubiquitination of TRAF6 and RIP1.

KEY FINDINGS

SFN improved LPS-induced neurocognitive dysfunction in rats. It inhibited the neuroinflammation and activation of NF-κB pathway induced by LPS. The modulation of TRAF6 and RIP1 ubiquitination by Cezanne was playing a pivotal role in relation to the mechanism of SFN inhibiting NF-κB pathway.

SIGNIFICANCE

The results of our study demonstrated that SFN could attenuate LPS-induced neuroinflammation through the modulation of Cezanne/NF-κB signalling.

Triterpenoids isolated from Jatropha macrantha (Müll. Arg.) inhibit the NF-κB and HIF-1α pathways in tumour cells

Activity-guided fractionations of Jatropha macrantha Müll. Arg. led to the isolation of pomolic acid (1) and euscaphic acid (2). The potential for inhibition against NF-κB and HIF-1α production of these two compounds was tested in different tumour cell lines. Compounds 1 and 2 showed an inhibitory activity of HIF-1α in the SK-MEL-28 (IC₅₀=3.01 ± 0.02 μM and 3.78 ± 0.02 μM), A549 (IC₅₀=9.97 ± 0.01 μM and 10.25 ± 0.01 μM) and U-373 MG (IC₅₀=6.34 ± 0.02 μM and 8.85 ± 0.02 μM) cell lines. In addition, compounds 1 and 2 showed an inhibitory activity on NF-κB in SK-MEL-28 (IC₅₀=1.05 ± 0.02 μM and 2.71 ± 0.01 μM), A549 (IC₅₀=3.63 ± 0.01 μM and 3.73 ± 0.02 μM) and U-373 MG (IC₅₀=2.55 ± 0.02 μM and 3.39 ± 0.01 μM) cell lines. This is the first report that isolates these compounds from J. macrantha and tests their antitumor potential.

Stress Response Simulated by Continuous Injection of ACTH Attenuates Lipopolysaccharide-Induced Inflammation in Porcine Adrenal Gland

On modern farms, animals are at high risk of bacterial invasion due to environmental stress factors. The adrenal gland is the terminal organ of the stress response. The crosstalk between adrenal endocrine stress and innate immune response is critical for the maintenance of immune homeostasis during inflammation. Thus, it's important to explore whether stresses play a pivotal role in lipopolysaccharide (LPS)-induced inflammatory response in the porcine adrenal gland. Thirty-days-old Duroc × Landrace × Large White crossbred piglets (12 ± 0.5 kg) were randomly allocated into four groups in a 2 × 2 factorial arrangement of treatments, including ACTH pretreatment (with or without ACTH injection) and LPS challenge (with or without LPS injection). Each group consisted of six male piglets. The results showed that our LPS preparation alone induced mRNA expressions of IL-1β, IL-6, TNF-α, IL-10, COX-2, TLR2, TLR4, and GR (P < 0.05). ACTH pretreatment downregulated the TLR2 mRNA and IL-6 protein level induced by our LPS preparation significantly (P < 0.05) by one-way ANOVA analysis. Treatment with LPS alone extremely significantly decreased ssc-miR-338 levels (P < 0.01). Interaction of ACTH × LPS was significant for cNOS level (P = 0.011) and ssc-miR-338 expression (P = 0.04) by two-way ANOVA analysis. The LPS treatment significantly downregulated cNOS levels (P < 0.01), which was significantly attenuated by ACTH pretreatment (P < 0.05). Lipopolysaccharide alone did not affect ssc-miR-146b expression levels compared to that in the vehicle group. However, ACTH pretreatment in combination with LPS significantly increased this micro-RNA expression (P < 0.05). TLRs 1–10 were all expressed in adrenal tissue. The LPS challenge alone induced remarkable compensatory mitochondrial damages at the ultrastructural level, which was alleviated by ACTH pretreatment. Accordingly, ACTH pretreatment was able to block LPS-induced secretion of local adrenal cortisol (P < 0.05). Taken together, our results demonstrate that ACTH pretreatment seems to attenuate LPS-induced mitochondria damage and inflammation that decreased cNOS activity in the adrenal gland and ultimately returned local adrenal cortisol to basal levels at 6 h post LPS injection.

Fecal medicines used in traditional medical system of China: a systematic review of their names, original species, traditional uses, and modern investigations

In China, the medical use of fecal matter (fresh fecal suspension or dry feces) can be dated back to the fourth century, approximately 1700 years ago. In long-term clinical practice, Chinese doctors have accumulated unique and invaluable medical experience in the use of fecal materials. In view of their good curative effect and medicinal potential, fecal medicines should be paid much attention. This study aimed to provide the first comprehensive data compilation of fecal medicines used in various Chinese traditional medical systems by bibliographic investigation of 31 medicine monographs and standards. A total of 54 fecal medicines were found to be used in 14 traditional Chinese medical systems. Their names, original species, medicinal forms, and traditional uses were described in detail. These fecal medicines were commonly used to treat gastrointestinal, nervous system, skin, and gynecological diseases. Commonly used fecal medicines include Wu-Ling-Zhi, Jiu-Fen and Hei-Bing-Pian. The information summarized in this study can provide a good reference for the development and utilization of fecal medicines. Further studies are necessary to prove their medicinal value, identify their active ingredients, and elucidate their mechanisms of action so that more people can accept these special medicines.

Possible involvement of metformin in downregulation of neuroinflammation and associated behavioural changes in mice

Metformin (MET), a biguanide oral hypoglycaemic agent, recently has been shown to be effective in various conditions other than type-2 diabetes including cancer, stroke, weight reduction, and polycystic ovarian syndrome, to name a few. MET has also possessed antioxidant and antiinflammatory properties by activation of AMPK . This study was aimed at evaluating the effects of MET on lipopolysaccharide (LPS)-induced systemic and neuroinflammation, oxidative stress, and behavioural changes. The study consisted of six groups, where three selected doses of MET (100, 200, and 300 mg/kg) were employed in male Swiss albino mice, with one group of imipramine (IMI), saline, and LPS each. Systemic inflammation was induced by injecting LPS (1.5 mg/kg) by intraperitoneal route. A battery of behavioural tests including open field, forced swim, and tail suspension tests were employed to assess the impact of systemic inflammation on exploratory behaviour and learned helplessness. LPS induced significant immobility with profound symptoms of sickness behaviour. Furthermore, LPS led to significant increase in serum and brain proinflammatory cytokines TNF-α and IL-6; and also increased lipid peroxidation with reduced glutathione levels. Pretreatment of the animals with 100 and 200 mg/kg of MET significantly reduced both systemic and central inflammatory markers along with protecting against LPS-induced oxidative stress. The higher dose, 300 mg/kg of MET was not effective against most of LPS-induced biochemical changes. Our preliminary results from this study suggest the antiinflammatory and neuroprotective effects of MET in LPS-induced model of sickness behaviour and neuroinflammation.

Caffeic Acid Prevented LPS-Induced Injury of Primary Bovine Mammary Epithelial Cells through Inhibiting NF-κB and MAPK Activation

In our previous study, lipopolysaccharide (LPS) significantly reduced the cell viability of primary bovine mammary epithelial cells (bMEC) leading to cell apoptosis, which were prevented by caffeic acid (CA) through inhibiting NF-κB activation and reducing proinflammatory cytokine expression. While the underlying mechanism remains unclear, here, we determined that LPS induced the extensive microstructural damage of bMEC, especially the mitochondria and endoplasmic reticulum. Then, the obvious reduction of mitochondrial membrane potential and expression changes of apoptosis-associated proteins (Bcl-2, Bax, and casepase-3) indicated that apoptosis signaling through the mitochondria should be responsible for the cell viability decrease. Next, the high-throughput cDNA sequencing (RNA-Seq) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were employed to verify that the MAPK and JAK-STAT signaling pathways also were the principal targets of LPS. Following, the critical proteins (ERK, JNK, p38, and c-jun) of the MAPK signaling pathways were activated, and the release of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8) regulated by NF-κB and MAPKs was significantly increased, which can promote a cascade of inflammation that induces cell injury and apoptosis. Meanwhile, CA significantly inhibited the activation of MAPKs and the release of proinflammatory cytokines in a dose-dependent manner, which were similar to its effects on the NF-κB activation that we previously published. So we concluded that CA regulates the proteins located in the upstream of multiple cell signal pathways which can reduce the LPS-induced activation of NF-κB and MAPKs, thus weakening the inflammatory response and maintaining cell structure and function, which accordingly inhibit apoptosis.

Ferulic Acid Rescues LPS-Induced Neurotoxicity via Modulation of the TLR4 Receptor in the Mouse Hippocampus

Microglia play a crucial role in the inflammatory brain response to infection. However, overactivation of microglia is neurotoxic. Toll-like receptor 4 (TLR4) is involved in microglial activation via lipopolysaccharide (LPS), which triggers a variety of cytotoxic pro-inflammatory markers that produce deleterious effects on neuronal cells. Ferulic acid (FA) is a phenolic compound that exerts antioxidant and anti-inflammatory effects in neurodegenerative disease. However, the manner in which FA inhibits neuroinflammation-induced neurodegeneration is poorly understood. Therefore, we investigated the anti-inflammatory effects of FA against LPS-induced neuroinflammation in the mouse brain. First, we provide evidence that FA interferes with TLR4 interaction sites, which are required for the activation of microglia-induced neuroinflammation, and further examined the potential mechanism of its neuroprotective effects in the mouse hippocampus using molecular docking simulation and immunoblot analysis. Our results indicated that FA treatment inhibited glial cell activation, p-JNK, p-NF_KB, and downstream signaling molecules, such as iNOS, COX-2, TNF-α, and IL-1β, in the mouse hippocampus and BV2 microglial cells. FA treatment strongly inhibited mitochondrial apoptotic signaling molecules, such as Bax, cytochrome C, caspase-3, and PARP-1, and reversed deregulated synaptic proteins, including PSD-95, synaptophysin, SNAP-25, and SNAP-23, and synaptic dysfunction in LPS-treated mice. These findings demonstrated that FA treatment interfered with the TLR4/MD2 complex binding site, which is crucial for evoking neuroinflammation via microglia activation and inhibited NF_KB likely via a JNK-dependent mechanism, which suggests a therapeutic implication for neuroinflammation-induced neurodegeneration.

Anti-inflammatory and toxicological evaluation of Moussonia deppeana (Schldl. & Cham) Hanst and Verbascoside as a main active metabolite

ETHNOPHARMACOLOGICAL RELEVANCE

Moussonia deppeana, known as Tlachichinole, is a Mexican medicinal plant used for treatment of inflammatory diseases, influenza, diarrhea, gastrointestinal disorders and arthritis.

AIM OF THE STUDY

In this paper the antioxidant and anti-inflammatory activities as well as the acute and sub-acute toxicological effects were evaluated for the ethanolic extract from aerial parts of M. deppeana, also its phytochemical analysis is described.

MATERIALS AND METHODS

Phytochemical analysis and compound isolation were performed with thin layer chromatography. The chemical identification of the main compound was performed by (1)H NMR (COSY, NOESY, HSQC and HMBC) spectra. In vitro antioxidant capacity and total phenolic content for the ethanolic extract and its primary fractions was determined by DPPH and Folin-Ciocalteu reagent. Acute and subacute toxicity tests were evaluated on Balb/C mice. Finally acute anti-inflammatory evaluation was tested for a local (TPA) and systemic (carrageenan) murine model.

RESULTS

The main compound isolated from the ethanolic extract of M. deppeana was Verbascoside, which was isolated from F3 and was identified by (1)H NMR and COSY data. Furthermore oleanolic and ursolic acids were isolated from primary fractions F1 and F2. Ethanolic extract showed IC50 = 6.71mg/mL for DPPH test and 664.12µg QE/mL for the total phenolic content. The LD50 value was >2g/kg by i.g. route in male and female mice. Sub-acute administration (28 days) of the ethanolic extract (1g/kg) did not cause lethality or alter any hematological and biochemical parameters, in addition, histological analysis of the major organs exhibited no structural changes. Anti-inflammatory activity of the ethanolic extract showed an ED50 = 1.5mg/ear and 450mg/kg for TPA and carrageenan test, respectively. Primary fractions generated moderate local and systemic anti-inflammatory activity.

CONCLUSION

The ethanolic extract from the aerial parts of M. deppeana did not cause any lethality or adverse effect in either of the acute and sub-acute toxicity tests. This exhibited an important local and systemic anti-inflammatory activity and also moderate antioxidant capacity. Moreover, the primary fraction F2 was more active for the TPA model while the primary fraction F3 was most active in the carrageenan model in vivo. The main compound isolated from F3 was verbascoside; on the other hand also ursolic and oleanolic acids were isolated from F1 and F2.

Isolation of a New Homomonoterpene from Madhuca Pasquieri and Effect of Isolated Compounds on NO Production

A new homomonoterpene, l,3,3-trimethyl-7-oxabicyclo[3.1.1]hexa-9-en-10-oic acid, named madhusic acid A (1), together with ten known compounds (2-11) were isolated from the methanolic extract of the dried leaves of Madhuca pasquieri (Dubard) H. J. Lam. The structure of the new compound was elucidated on the basis of ID, 2D NMR (COSY, HMQC, and HMBC) and mass spectral analyses. We examined the effects of the isolated compounds against LPS-induced NO production in macrophage RAW264.7 cells and compound 2 showed effective activity with an IC50 value of 14.5 μM.

Protective effect of EC-18, a synthetic monoacetyldiglyceride on lung inflammation in a murine model induced by cigarette smoke and lipopolysaccharide

The antler of Sika deer (Cervus nippon Temminck) has been used a natural medicine in Korea, China and Japan, and a monoacetyldiaglyceride (1-palmitoyl-2-linoleoyl-3-acetylglycerol, PLAG) was found in the antler of Sika deer as a constituent for immunomodulation. In this study, we investigated protective effects of EC-18 (a synthetic copy of PLAG) on inflammatory responses using a cigarette smoke with lipopolysaccharide (LPS)-induced airway inflammation model. Mice were exposed to cigarette smoke for 1h per day for 3days. Ten micrograms of LPS dissolved in 50μL of PBS was administered intra nasally 1h after the final cigarette smoke exposure. EC-18 was administered by oral gavage at doses of 30 and 60mg/kg for 3days. EC-18 significantly reduced the number of neutrophils, reactive oxygen species production, cytokines and elastase activity in bronchoalveolar lavage fluid (BALF) compared with the cigarette smoke and LPS induced mice. Histologically, EC-18 attenuated airway inflammation with a reduction in myeloperoxidase expression in lung tissue. Additionally, EC-18 inhibited the phosphorylation of NF-κB and IκB induced by cigarette smoke and LPS exposure. Our results show that EC-18 effectively suppresses neutrophilic inflammation induced by cigarette smoke and LPS exposure. In conclusion, this study suggests that EC-18 has therapeutic potential for the treatment of chronic obstructive pulmonary disease.

Dioscin attenuates renal ischemia/reperfusion injury by inhibiting the TLR4/MyD88 signaling pathway via up-regulation of HSP70

We previously reported the effect of dioscin against hepatic ischemia/reperfusion injury (IRI) in rats. However, little is known concerning the role of dioscin in renal IRI. In the present study, rats were subjected to IRI and dioscin was intragastrically administered for seven consecutive days before surgery. In vitro models of hypoxia/reoxygenation were developed in NRK-52E and HK-2 cells, which were prophylactically treated with or without dioscin. The results showed that dioscin significantly decreased serum BUN and Cr levels, and markedly attenuated cell injury. Mechanistic studies showed that dioscin significantly increased HSP70 levels, decreased the levels of TLR4, MyD88, TRAF6, COX-2, JNK, ERK and p38 MAPK phosphorylation, suppressed the nuclear translocation of NF-κB and HMGB1, and subsequently decreased the mRNA levels of IL-1β, IL-6, TNF-α, ICAM-1 and IFN-γ. Moreover, HSP70 siRNA or TLR4 DNA reversed the nephroprotective effects of dioscin, while dioscin still significantly down-regulated the TLR4 signaling pathway. Furthermore, by inhibiting MyD88 with ST2825 (a MyD88 inhibitor), renal IRI was significantly attenuated, suggesting that the effect of dioscin against renal IRI depended on MyD88. Our results suggested that dioscin had a potent effect against renal IRI through suppressing the TLR4/MyD88 signaling pathway by up-regulating HSP70. These data provide new insights for investigating the natural product with the nephroprotective effect against IRI, which should be developed as a new therapeutic agent for the treatment of acute kidney injury in the future.

MicroRNA-146a-5p attenuates neuropathic pain via suppressing TRAF6 signaling in the spinal cord

Glia-mediated neuroinflammation plays an important role in the pathogenesis of neuropathic pain. Our recent study demonstrated that TNF receptor associated factor-6 (TRAF6) is expressed in spinal astrocytes and contributes to the maintenance of spinal nerve ligation (SNL)-induced neuropathic pain. MicroRNA (miR)-146a is a key regulator of the innate immune response and was shown to target TRAF6 and reduce inflammation. In this study, we found that in cultured astrocytes, TNF-α, IL-1β, or lipopolysaccharide (LPS) induced rapid TRAF6 upregulation and delayed miR-146a-5p upregulation. In addition, miR-146a-5p mimic blocked LPS-induced TRAF6 upregulation, as well as LPS-induced c-Jun N-terminal kinase (JNK) activation and chemokine CCL2 expression in astrocytes. Notably, LPS incubation with astrocytes enhanced the DNA binding activity of AP-1 to the promoters of mir-146a and ccl2. TRAF6 siRNA or JNK inhibitor SP600125 significantly reduced LPS-induced miR-146a-5p increase in astrocytes. In vivo, intrathecal injection of TNF-α or LPS increased spinal TRAF6 expression. Pretreatment with miR-146a-5p mimic alleviated TNF-α- or LPS-induced mechanical allodynia and reduced TRAF6 expression. Finally, SNL induced miR-146a-5p upregulation in the spinal cord at 10 and 21days. Intrathecal injection of miR-146a-5p mimic attenuated SNL-induced mechanical allodynia and decreased spinal TRAF6 expression. Taken together, the results suggest that (1) miR-146a-5p attenuates neuropathic pain partly through inhibition of TRAF6 and its downstream JNK/CCL2 signaling, (2) miR-146a-5p is increased by the activation of TRAF6/JNK pathway. Hence, miR-146a-5p may be a novel treatment for chronic neuropathic pain.

Pentacyclic Triterpenoids Inhibit IKKβ Mediated Activation of NF-κB Pathway: In Silico and In Vitro Evidences

Pentacyclic Triterpenoids (PTs) and their analogues as well as derivatives are emerging as important drug leads for various diseases. They act through a variety of mechanisms and a majority of them inhibit the nuclear factor kappa-beta (NF-κB) signaling pathway. In this study, we examined the effects of the naturally occurring PTs on IκB kinase-β (IKKβ), which has great scientific relevance in the NF-κB signaling pathway. On virtual screening, 109 PTs were screened through the PASS (prediction of activity spectra of substances) software for prediction of NF-κB inhibitory activity followed by docking on the NEMO/IKKβ association complex (PDB: 3BRV) and testing for compliance with the softened Lipinski’s Rule of Five using Schrodinger (LLC, New York, USA). Out of the projected 45 druggable PTs, Corosolic Acid (CA), Asiatic Acid (AA) and Ursolic Acid (UA) were assayed for IKKβ kinase activity in the cell free medium. The UA exhibited a potent IKKβ inhibitory effect on the hotspot kinase assay with IC50 of 69 μM. Whereas, CA at 50 μM concentration markedly reduced the NF-κB luciferase activity and phospho-IKKβ protein expressions. The PTs tested, attenuated the expression of the NF-κB cascade proteins in the LPS-stimulated RAW 264.7 cells, prevented the phosphorylation of the IKKα/β and blocked the activation of the Interferon-gamma (IFN-γ). The results suggest that the IKKβ inhibition is the major mechanism of the PTs-induced NF-κB inhibition. PASS predictions along with in-silico docking against the NEMO/IKKβ can be successfully applied in the selection of the prospective NF-κB inhibitory downregulators of IKKβ phosphorylation.

Anti-hyperplasia effects of Rosa rugosa polyphenols in rats with hyperplasia of mammary gland

Rosa rugosa (Thunb.) is used in Chinese traditional medicine with the functions of promoting blood circulation, relieving the depressed liver and attenuating breast disorders. This study was to investigate the anti-hyperplasia effects of the polyphenols-rich fraction from R. rugosa (FRR) in rat. Rat model of hyperplasia of mammary gland (HMG) was induced by intramuscularly injected with estrogen (0.5mg/kg/d) for 25 days, and followed with progestogen (5mg/kg/d) for another 5 days. Meanwhile, FRR was orally given for 30 days. Then, the levels of estradiol and oxidative stress were assessed. The mammary expressions of AKT and JNK were evaluated by Western blot analysis. The expressions of NFκB-p65, COX-2 and VEGF were measured by immunohistochemical analysis. The whole results indicated that FRR could exert anti-hyperplasia effects in rat via modulating the mammary expression of JNK and AKT, as well as alleviating the NFκB related oxidative stress and inflammatory responses.

Sophocarpine attenuates toll-like receptor 4 in steatotic hepatocytes to suppress pro-inflammatory cytokines synthesis

BACKGROUND AND AIM

Sophocarpine, a tetracyclic quinolizidine alkaloid derived from Sophora alopecuroides L., has been documented that it can suppress pro-inflammatory cytokines synthesis in alleviating nonalcoholic steatohepatitis (NASH) in vivo. Toll-like receptor 4 (TLR4) is a pattern recognition receptor whose activation results in the production of several pro-inflammatory cytokines. It has been reported that TLR4 is upregulated in nonalcoholic fatty liver disease and plays an important role in the pathogenesis of NASH. This study aimed to examine the changes of TLR4 and its signaling pathways in sophocarpine's anti-inflammatory process on experimental NASH in vitro.

METHODS

Primary hepatocytes were isolated, and oleic acid-induced steatosis model was established. Cell Counting Kit-8 assay was used to detect the number of metabolically active mitochondria and viable cells. Immunocytochemistry analysis was applied to evaluating pro-inflammatory cytokines synthesis. Total RNA and protein were extracted for real-time polymerase chain reaction and Western blot detection.

RESULTS

Enhanced expression of TLR4 was observed in oleic acid-induced steatotic hepatocytes. Sophocarpine suppressed pro-inflammatory cytokines synthesis and reduced the expression of TLR4 in steatotic hepatocytes. Expression of TLR4 and pro-inflammatory cytokines recovered after sophocarpine was removed. Moreover, sophocarpine restrained the activation of nuclear factor-kappaB (NF-κB), c-Jun-N-terminal kinase (JNK), and Extracellular regulated protein kinases (ERK) signaling pathways in the anti-inflammatory process.

CONCLUSION

Sophocarpine could decrease the expression of TLR4 in steatotic hepatocytes and suppress pro-inflammatory cytokines synthesis. NF-κB, JNK, and ERK signaling pathways were important workable downstream pathways.

Effect of peroxisome proliferator-activated receptor γ on the cholesterol efflux of peritoneal macrophages in inflammation

Atherosclerosis, a chronic inflammatory disorder characterized by lipid and cholesterol accumulation, is the principal contributing factor to the pathology of cardiovascular disease. Macrophages contribute to plaque development by internalizing native and modified lipoproteins that convert them into cholesterol-rich foam cells. With multiple factors, including hypercholesterolemia and inflammation, promoting atherosclerosis, it is of great significance to elucidate how the mechanism of cholesterol efflux from the macrophages changes and the role of peroxisome proliferator-activated receptor γ (PPARγ) in these situations. Following isolation and culture of peritoneal macrophages from C57BL/6 mice in the present study, the cells were divided into three groups: The control group, the ciglitazone group and the PPARγ antisense oligonucleotide group. The expression of PPARγ and nuclear factor of κ light polypeptide gene enhancer in B‑cells inhibitor α (IκBα) in each group was observed through the levels of protein and mRNA, and then the cholesterol efflux of each group was investigated. In addition, the same experiments were repeated following stimulation of each group with lipopolysaccharide (LPS). No significant difference in the expression levels of PPARγ between the control group and ciglitazone group was observed. The expression levels of PPARγ in the PPARγ antisense oligonucleotide group were evidently lower than those in the control group. Subsequent to stimulation with LPS, the expression levels of PPARγ in the three groups were higher than those of each group prior to stimulation. The cholesterol efflux of the PPARγ antisense oligonucleotide group was clearly suppressed following stimulation with LPS in comparison with that of the other groups. PPARγ contributes to anti-inflammation by protecting IκBα from being phosphorylated and degraded and promoting cholesterol efflux from peritoneal macrophages in inflammation.

Pseudoginsenoside-F11 (PF11) exerts anti-neuroinflammatory effects on LPS-activated microglial cells by inhibiting TLR4-mediated TAK1/IKK/NF-κB, MAPKs and Akt signaling pathways

Pseudoginsenoside-F11 (PF11), an ocotillol-type ginsenoside, has been shown to possess significant neuroprotective activity. Since microglia-mediated inflammation is critical for induction of neurodegeneration, this study was designed to investigate the effect of PF11 on activated microglia. PF11 significantly suppressed the release of ROS and proinflammatory mediators induced by LPS in a microglial cell line N9 including NO, PGE2, IL-1β, IL-6 and TNF-α. Moreover, PF11 inhibited interaction and expression of TLR4 and MyD88 in LPS-activated N9 cells, resulting in an inhibition of the TAK1/IKK/NF-κB signaling pathway. PF11 also inhibited the phosphorylation of Akt and MAPKs induced by LPS in N9 cells. Importantly, PF11 significantly alleviated the death of SH-SY5Y neuroblastoma cells and primary cortical neurons induced by the conditioned-medium from activated microglia. At last, the effect of PF11 on neuroinflammation was confirmed in vivo: PF11 mitigated the microglial activation and proinflammatory factors expression obviously in both cortex and hippocampus in mice injected intrahippocampally with LPS. These findings indicate that PF11 exerts anti-neuroinflammatory effects on LPS-activated microglial cells by inhibiting TLR4-mediated TAK1/IKK/NF-κB, MAPKs and Akt signaling pathways, suggesting its therapeutic implication for neurodegenerative disease associated with neuroinflammation.

Tangeretin exerts anti-neuroinflammatory effects via NF-κB modulation in lipopolysaccharide-stimulated microglial cells

Increasing evidence suggests that tangeretin, a flavonoid from citrus fruit peels, exhibits anti-inflammatory properties and neuroprotective effects in animal disease models. However, the underlying molecular mechanisms are not clearly understood. In this study, we investigated whether tangeretin suppresses excessive microglial activation implicated in the resulting neurotoxicity following stimulation with lipopolysaccharide (LPS) in primary rat microglia and BV-2 microglial cell culture models. The results showed that tangeretin decreased the production of nitric oxide (NO), prostaglandin E₂ (PGE₂), tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6), in a dose-dependent manner. Additionally, it inhibited the LPS-induced expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) (examined at the protein level) as well as TNF-α, IL-1β, and IL-6 (examined at the mRNA level) in microglial cells. To explore the possible mechanisms underlying these inhibitions by tangeretin, we examined the mitogen-activated protein kinase (MAPK) protein levels and the NF-κB protein signaling pathway. Tangeretin clearly inhibited LPS-induced phosphorylation of ERK, N-terminal Kinase (JNK), and p38. In addition, tangeretin markedly reduced LPS-stimulated phosphorylation of IκB-α and IKK-β, as well as the nuclear translocation of the p65 subunit of pro-inflammatory transcription factor NF-κB. Taken together, these results support further exploration of the therapeutic potential and molecular mechanism of tangeretin in relation to neuroinflammation and neurodegenerative diseases accompanied by microglial activation.

Desoxyrhapontigenin, a potent anti-inflammatory phytochemical, inhibits LPS-induced inflammatory responses via suppressing NF-κB and MAPK pathways in RAW 264.7 cells

This study investigates the anti-inflammatory effects of a stilbene compound, desoxyrhapontigenin, which was isolated from Rheum undulatum. To determine the anti-inflammatory effects of this compound, lipopolysaccharide (LPS)-induced RAW 264.7 macrophages were treated with different concentrations of six stilbene derivatives. The results indicated that compared with other stilbene compounds, desoxyrhapontigenin (at 10, 30 and 50μM concentrations) significantly inhibited nitric oxide (NO) production, nuclear factor kappa B (NF-κB) activation, the protein expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression. Therefore, the anti-inflammatory mechanism of desoxyrhapontigenin was investigated in detail. The results of this investigation demonstrated that desoxyrhapontigenin suppressed not only LPS-stimulated pro-inflammatory cytokine secretions, including the secretions of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), but also PGE2 release. As assayed by electrophoretic mobility shift assays (EMSAs), desoxyrhapontigenin also produced the dose-dependent inhibition of the LPS-induced activation of NF-κB and AP-1. Moreover, desoxyrhapontigenin inhibited the protein expression of myeloid differentiation primary response gene 88 (MyD88), IκB kinase (IKK) phosphorylation and the degradation of IκBα. Activations of p-JNK1 and p-Akt were also significantly inhibited, and phosphorylation of p38 and ERK was down-regulated. A further study revealed that desoxyrhapontigenin (5 and 25mg/kg, i.p.) reduced paw swelling in carrageenan-induced acute inflammation model in vivo. On the whole, these results indicate that desoxyrhapontigenin showed anti-inflammatory properties by the inhibition of iNOS and COX-2 expression via the down-regulation of the MAPK signaling pathways and the inhibition of NF-κB and Akt activation.

Two new stereoisomeric antioxidant triterpenes from Potentilla fulgens

The roots of Potentilla fulgens have been used for a long time as a folk remedy for many ailments without having information on its pharmacological action. Of the various extracts prepared by partitioning of the methanol extract, the ethyl acetate fraction was found to possess better antioxidant and cytotoxic activities. The degree of reduction in cloning efficiencies of MCF-7 cell lines was more with ethyl acetate than with hexane fraction of the root-extract. Hence, this fraction was further purified and nine compounds, including two new ursane type triterpenoids Fulgic acid A (4) and Fulgic acid B (5), were identified and characterized. Other compounds were identified as ursolic acid, euscaphic acid, corosolic acid, epicatechin, catechin, p-hydroxybenzaldehyde and gallic acid. Chemical structures were elucidated by spectroscopic methods, especially ESIHRMS and 2D NMR techniques. The new compounds showed good antioxidant activity and therefore this plant can be a source of natural antioxidants.