Astragalin suppresses inflammatory responses via down-regulation of NF-κB signaling pathway in lipopolysaccharide-induced mastitis in a murine model

Astragalin improves cognitive disorder in Alzheimer's disease: Based on network pharmacology and molecular docking simulation

We investigate the mechanism of action of astragalin (AST) in the treatment of Alzheimer's disease (AD). Network pharmacology was conducted to analyze the relationships among AST, AD, and neuroinflammation, The APP/PS1 transgenic mice with AD were used in the experiments; to be specific, the influence of AST on the behavior of mice was analyzed by Morris water maze and eight-arm radial maze tests, the tissue inflammatory factor levels were detected by ELISA, and pathological changes were analyzed by H&E and immunohistochemical staining. Analysis results of network pharmacology suggested that AST exerted the multi-target effect on neuroinflammation in AD. Through molecular docking and dynamics analyses, COX2 might be the target of AST. Moreover, animal experimental results demonstrated that AST improved the behavior of AD mice, and enhanced the motor and memory abilities, meanwhile, it suppressed the expression of inflammatory factors in tissues and the activation of microglial cells. this study discovers that AST can suppress microglial cell activation via COX2 to improve neuroinflammation in AD.

Health Benefits of Antioxidant Bioactive Compounds in Ginger (Zingiber officinale) Leaves by Network Pharmacology Analysis Combined with Experimental Validation

Network pharmacology is an ideal tool to explore the effects of therapeutic components derived from plants on human metabolic diseases that are linked to inflammation. This study investigated the antioxidant effects of ginger leaves (GLs) and predicted targets for antioxidant activity. Quantitative and free radical scavenging analyses were performed to detect the main bioactive compounds of GLs and evaluate their antioxidant activities. Chemical diversity and network pharmacology approaches were used to predict key antioxidant components of GLs and their molecular targets. Nine major bioactive compounds of GLs were quantified using an internal standard method, and the antioxidant activity was evaluated using the DPPH and ABTS free radical scavenging methods. We first built the compound-gene-pathways and protein-protein interaction networks of GLs-related antioxidant targets and then conducted gene ontology and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway enrichment analyses. Molecular docking results show that astragalin, a compound isolated from GLs, had the highest level of connectivity in the compound-target network and was involved in inflammation-related biosynthesis by directly impacting cytokine gene expression and PTGS2 inhibition markers. These findings not only suggest that the compounds isolated from GLs can be developed as potential antioxidants, but also demonstrate the applicability of network pharmacology to assess the potential of foods for disease treatment.

Research Progress on Anti-Inflammatory Effects and Related Mechanisms of Astragalin

Chronic inflammation is a significant contributor to the development of cancer, cardiovascular disease, diabetes, obesity, autoimmune disease, inflammatory bowel disease, and other illnesses. In the academic field, there is a constant demand for effective methods to alleviate inflammation. Astragalin (AST), a type of flavonoid glycoside that is the primary component in several widely used traditional Chinese anti-inflammatory medications in clinical practice, has garnered attention from numerous experts and scholars. This article focuses on the anti-inflammatory effects of AST and conducts research on relevant literature from 2003 to 2023. The findings indicate that AST demonstrates promising anti-inflammatory potential in various models of inflammatory diseases. Specifically, AST is believed to possess inhibitory effects on inflammation-related factors and protein levels in various in vitro cell models, such as macrophages, microglia, and epithelial cells. In vivo studies have shown that AST effectively alleviates neuroinflammation and brain damage while also exhibiting potential for treating moderate diseases such as depression and stroke; it also demonstrates significant anti-inflammatory effects on both large and small intestinal epithelial cells. Animal experiments have further demonstrated that AST exerts therapeutic effects on colitis mice. Molecular biology studies have revealed that AST regulates complex signaling networks, including NF-κB, MAPK, JAK/STAT pathways, etc. In conclusion, this review will provide insights and references for the development of AST as an anti-inflammatory agent as well as for related drug development.

Astragalin: a food-origin flavonoid with therapeutic effect for multiple diseases

Naturally occurring flavonoids have long been utilized as essential templates for the development of novel drugs and as critical ingredients for functional foods. Astragalin (AG) is a natural flavonoid that can be isolated from a variety of familiar edible plants, such as the seeds of green tea, Morus alba L., and Cuscuta chinensis. It is noteworthy that AG has a wide range of pharmacological activities and possesses therapeutic effects against a variety of diseases, covering cancers, osteoarthritis, osteoporosis, ulcerative colitis, mastitis, obesity, diabetes mellitus, diabetic complications, ischemia/reperfusion injury, neuropathy, respiratory diseases, and reproductive system diseases. This article reviewed the natural source and pharmacokinetics of AG and systematically summarized the pharmacological activities and potential mechanisms of AG in treating diverse diseases in order to promote the development of AG as a functional food, in doing so providing references for its clinical application in disease therapy.

Deep Eutectic Solvent-Based Microwave-Assisted Extraction for the Extraction of Seven Main Flavonoids from Ribes mandshuricum (Maxim.) Kom. Leaves

Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from Ribes mandshuricum leaves, namely, trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol. After the completion of the extraction process, macroporous adsorption resin was used for the purification of seven flavonoids. The BBD (Box–Behnken design) method combined with RSM (response surface methodology) was applied to acquire the optimal operating conditions of DES-MAE. The optimal parameters were: temperature: 54 °C, time: 10 min, extraction solvent: choline chloride/lactic acid with a 1:2 mass ratio, water content: 25%, and liquid/solid ratio: 27 mL/g. The yields of the seven target flavonoids were 4.78, 2.57, 1.25, 1.15, 0.34, 0.32, and 0.093 mg/g DW (dry weight), respectively. The direct purification of trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol in DES-MAE solution was achieved by using macroporous resin X-5. The recoveries were 87.02%, 81.37%, 79.64%, 87.13%, 97.36%, 88.08%, and 99.39%, respectively. The results showed that DES-MAE followed by MRCC (macroporous resin column chromatography) represents a promising approach to extracting and separating active components from plants.

A Novel TLR4-SYK Interaction Axis Plays an Essential Role in the Innate Immunity Response in Bovine Mammary Epithelial Cells

Mammary gland epithelium, as the first line of defense for bovine mammary gland immunity, is crucial in the process of mammary glands’ innate immunity, especially that of bovine mammary epithelial cells (bMECs). Our previous studies successfully marked SYK as an important candidate gene for mastitis traits via GWAS and preliminarily confirmed that SYK expression is down-regulated in bMECs with LPS (E. coli) stimulation, but its work mechanism is still unclear. In this study, for the first time, in vivo, TLR4 and SYK were colocalized and had a high correlation in mastitis mammary epithelium; protein−protein interaction results also confirmed that there was a direct interaction between them in mastitis tissue, suggesting that SYK participates in the immune regulation of the TLR4 cascade for bovine mastitis. In vitro, TLR4 also interacts with SYK in LPS (E. coli)-stimulated or GBS (S. agalactiae)-infected bMECs, respectively. Moreover, TLR4 mRNA expression and protein levels were little affected in bMECsSYK- with LPS stimulation or GBS infection, indicating that SYK is an important downstream element of the TLR4 cascade in bMECs. Interestingly, IL-1β, IL-8, NF-κB and NLRP3 expression in LPS-stimulated or GBS-infected bMECsSYK- were significantly higher than in the control group, while AKT1 expression was down-regulated, implying that SYK could inhibit the IL-1β, IL-8, NF-κB and NLRP3 expression and alleviate inflammation in bMECs with LPS and GBS. Taken together, our solid evidence supports that TLR4/SYK/NF-κB signal axis in bMECs regulates the innate immunity response to LPS or GBS.

Nisin Z attenuates lipopolysaccharide-induced mastitis by inhibiting the ERK1/2 and p38 mitogen-activated protein kinase signaling pathways

Nisin Z is a possible alternative for treating bovine mastitis by inhibiting mastitis-causing pathogens and having anti-inflammatory activity. However, the anti-inflammatory mechanism of nisin Z on mastitis is unknown. Our study aimed to investigate the mechanisms of nisin Z on mastitis. Our results showed that nisin Z inhibited the activation of the ERK1/2 and p38 mitogen-activated protein kinase (MAPK) signaling pathway, decreased the release of pro-inflammatory cytokines (i.e., tumor necrosis factor-α, IL-1β, and IL-6), and increased the anti-inflammatory cytokine (IL-10) in lipopolysaccharide (LPS)-induced MCF10A cells. After intraperitoneal injection, nisin Z significantly decreased inflammatory cell infiltration in the mammary gland, as well as decreased myeloperoxidase and pro-inflammatory cytokines in serum and mammary gland. Western blot analysis revealed that nisin Z also dramatically suppressed the activation of the ERK1/2 and p38 MAPK signaling pathways in LPS-induced mastitis mice. We also found that nisin Z treatment could enhance the blood-milk barrier. In summary, our study demonstrated that nisin Z exerted an anti-inflammatory effect by inhibiting the ERK1/2 and p38 MAPK signaling pathway and promoting the blood-milk barrier on LPS-induced mastitis.

Evaluation of Anti-Inflammatory Effect of Moringa oleifera Lam. and Cyanthillium cinereum (Less) H. Rob. Lozenges in Volunteer Smokers

Smokers have high plaque accumulation that initiates gingival inflammation and progresses to periodontitis. Thus, oral hygiene to control microbial plaque formation is an effective method of preventing gingivitis. Medicinal plants such as Moringa oleifera Lam. (MO) and Cyanthillium cinereum (Less.) H. Rob. (CC) have an anti-inflammatory effect that might improve oral health in smokers. This study evaluated the effect of MO leaf and CC extracts using MO lozenges and a combination of MO + CC lozenges on oral inflammation and gingivitis in volunteer smokers. Lozenges consisting of MO and CC extracts were developed and studied in vivo. The results showed that lozenges significantly reduced oral inflammation and gingivitis in volunteers. The gingival index (GI) of group III (MO + CC lozenges) significantly decreased, while the percentage decrease of oral inflammation in group II (MO lozenges) was significantly higher than the other groups. The percentage decrease of GI values in group II (MO lozenges) and group III (MO + CC lozenges) were significantly higher than the placebo group I. Our findings indicated that MO and MO + CC lozenges reduced oral inflammation and gingivitis and showed potential to improve oral health in smokers.

Thesium chinense Turcz.: An ethnomedical, phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Thesium chinense Turcz. has been used to treat mastitis, pulmonitis, tonsillitis, iaryngopharyngitis and upper respiratory tract infections in the indigenous medicine of China for a long history. Presently, several pharmaceutics prepared by this medical herb have been clinically used for the therapy of infectious diseases.

AIM OF THE REVIEW

This review aims to comprehensively summarize the current researches on the ethnomedical, phytochemical and pharmacological aspects of T. chinense, and discuss their possible opportunities for the future research.

MATERIALS AND METHODS

Extensive database searches, including Web of Science, SciFinder, Google Scholar and China Knowledge Resource Integrated, were performed using keywords such as 'Thesium chinense', 'Bai Rui Cao', and their chemical constituents. In addition, local classic herbal literature on ethnopharmacology and relevant textbooks were consulted to provide a comprehensive survey of this ethnomedicine.

RESULTS

Thirty four chemical constituents, including flavonoids, alkaloids, and terpenoids, have been identified from T. chinense. Of which, flavonoids are the predominant and characteristic constituents. The crude extracts, the purified constituents, and commercial available pharmaceutics have displayed diverse in vitro and in vivo pharmacological functions (e.g. anti-inflammation, antimicrobial activity, analgesic effect, hepaprotection), and are particularly useful as a potential therapeutic agent against inflammation-related diseases.

CONCLUSIONS

T. chinense is an important ethnomedical medicine and possesses a satisfying effect for treating inflammation, microbial infection, and upper respiratory diseases. It has received plenty of researches on its phytochemical and pharmacological aspects since 1970s. These findings definitely establish the link between chemical composition and pharmacological application, and support the ethnomedical use of T. chinense in the indigenous medicine of China. However, chemical composition of this plant and the molecular mechanisms of purified constituents have not been comprehensively investigated, and thus the trace constituents and the therapeutic targets of bioactive constituents deserve a further exploration. Collectively, the researchers should pay more attention to a better understanding and application of this ethnomedical plant.

Astragalin Inhibits the Proliferation and Migration of Human Colon Cancer HCT116 Cells by Regulating the NF-κB Signaling Pathway

Astragalin is a flavonoid found in a variety of natural plants. It has anti-inflammatory, anti-oxidant effects and has inhibited effects against several malignant tumor cell types. However, its effects on colon cancer and the molecular mechanisms have remained to be elucidated. In this study, we evaluated the inhibitory effect of astragalin on proliferation and migration of human colon cancer HCT116 cells in vitro and in vivo. Furthermore, we elucidated the mechanism of these effects. The results showed that astragalin significantly inhibited the proliferation and diffusion of HCT116 cells by induced apoptosis (by modulation of Bax, Bcl-2, P53, caspase-3, caspase 6, caspase 7, caspase 8, caspase 9 protein express) and cell cycle arrest (by modulation of Cyclin D1, Cyclin E, P21, P27, CDK2, CDK4 protein express). Moreover, astragalin suppressed HCT116 cell migration by inhibiting the expression of matrix metalloproteinases (MMP-2, MMP-9). In addition, astragalin significantly downregulated the expression of key proteins in the NF-κB signaling pathway and inhibited the transcriptional activity of NF-κB P65 stimulated with inflammatory cytokines TNF-α, thereby inhibiting the growth of colon cancer cells in vitro. Our further investigations unveiled astragalin gavage significantly reduced the proliferation of colon cancer xenograft in nude mice, in vivo experiments showed that tumor growth was related to decreased expression of apoptotic proteins in tumor tissues and decreased activity of the NF-κB signaling pathway. In summary, our results indicated that astragalin inhibits the proliferation and growth of colon cancer cells in vivo and in vitro via the NF-κB pathway. Therefore, astragalin maybe become a potential plant-derived antitumor drug for colon cancer.

Astragalin Inhibits Nuclear Factor-κB Signaling in Human Colonic Epithelial Cells and Attenuates Experimental Colitis in Mice

Background/Aims

Astragalin (kaempferol-3-O-β-D-glucoside) is a flavonoid isolated from the leaves of persimmon or Rosa agrestis. Astragalin exhibits various anti-inflammatory properties; however, little is known about its therapeutic potential for inflammatory bowel disease (IBD). This study aims to investigate the anti-inflammatory effect of astragalin via blockade of the nuclear factor κB (NF-κB) signaling pathway in human colonic epithelial cells and a murine colitis model.

Methods

HCT-116 and HT-29 human colonic epithelial cells were pretreated with astragalin and stimulated with tumor necrosis factor-α (TNF-α). Cell viability was assessed by the MTS assay. Real-time reverse transcription polymerase chain reaction was used to analyze the messenger RNA expression of the inflammatory cytokines interleukin (IL)-6 and IL-8. The effect of astragalin on the NF-κB pathway was evaluated by Western blot analysis of inhibitor of NF-κB alpha (IκBα) phosphorylation/degradation and by electrophoretic mobility shift assay. Dextran sulfate sodium (DSS)-induced acute murine colitis model was used for in vivo experiments.

Results

Astragalin strongly suppressed the expression of proinflammatory cytokines in human colonic epithelial cells in a dose-dependent manner. Western blot analysis showed that astragalin inhibited IκBα phosphorylation/degradation. Additionally, astragalin reduced the DNA binding activity of NF-κB. Astragalin alleviated colon shortening and improved the pathologic scores in DSS-induced acute murine colitis model. Furthermore, astragalin reduced the level of phosphorylated IκBα and decreased the production of the inflammatory cytokines IL-6, IL-8, and TNF-α in the DSS-treated colon mucosa.

Conclusions

Astragalin exerted an anti-inflammatory effect through NF-κB pathway inhibition and attenuated murine colitis. Astragalin is thus a potential therapeutic agent for IBD.

Astragalin Alleviates Neuropathic Pain by Suppressing P2X4-Mediated Signaling in the Dorsal Root Ganglia of Rats

Neurologic damage often leads to neuropathic pain, for which there are no effective treatments owing to its complex pathogenesis. The purinergic receptor P2X4 is closely associated with neuropathic pain. Astragalin (AST), a compound that is used in traditional Chinese medicine, has protective effects against allergic dermatitis and neuronal injury, but its mechanism of action is not well understood. The present study investigated whether AST can alleviate neuropathic pain in a rat model established by chronic constriction injury (CCI) to the sciatic nerve. The model rats exhibited pain behavior and showed increased expression of P2X4 and the activated satellite glial cell (SGC) marker glial fibrillary acidic protein in dorsal root ganglia (DRG). AST treatment partly abrogated the upregulation of P2X4, inhibited SGC activation, and alleviated pain behavior in CCI rats; it also suppressed ATP-activated currents in HEK293 cells overexpressing P2X4. These data demonstrate that AST relieves neuropathic pain by inhibiting P2X4 and SGC activation in DRG, highlighting its therapeutic potential for clinical pain management.

Oridonin Attenuates TNBS-induced Post-inflammatory Irritable Bowel Syndrome via PXR/NF-κB Signaling

To investigate the beneficial effects of oridonin, a diterpenoid compound isolated from Rabdosia rubescens, on the inflammatory response in TNBS-induced post-inflammatory irritable bowel syndrome (PI-IBS) model and the underlying mechanism. Using the PI-IBS rat model and Caco-2 cell lines, we found that intestinal barrier function reflected by lactulose/mannitol (L/M) ratio and tight junction protein level was significantly ameliorated by oridonin. We also demonstrated that oridonin abrogated inflammation through inhibiting the phosphorylation of NF-κBp65 as well as its downstream gene (iNOS, COX-2, IL-1β, and IL-6) level. Molecular docking studies confirmed the good binding activity between oridonin and PXR. In Caco-2 cell lines, oridonin markedly inhibited LPS-induced NF-κB activation in a PXR-dependent manner. Meanwhile, PXR and its target genes CYP3A4 and P-gp were induced by oridonin, which was associated with the decreased expression of NF-κB and the recovery of intestinal barrier. This study indicated that the therapeutic effect of oridonin on experimental PI-IBS through repairing intestinal barrier function may be closely associated with the regulatory role of PXR/NF-κB signaling pathway. Oridonin may serve as a PXR ligand for the development of drugs in the therapy for PI-IBS.

Antioxidant, Anti-Inflammatory, and Anti-Apoptotic Effects of Azolla pinnata Ethanolic Extract against Lead-Induced Hepatotoxicity in Rats

The current study investigated the protective potential of Azolla pinnate ethanolic extract (APE) against lead-induced hepatotoxicity in rats. Sixty male Wistar albino rats were randomly allocated into six groups (n = 10). The control group was orally administrated with saline. The second group received lead acetate (100 mg/kg body weight (BW) orally for 60 days). The third group was fed with APE (10 mg/kg BW orally for 60 days). The fourth group was administrated with lead acetate like the second group and APE like the third group, concomitantly, for 60 days. The fifth group was administrated with APE like the third group for 30 days, then orally administrated with the lead acetate like the second group for another 30 days. The sixth group was administrated with lead acetate like the second group for 30 days, then with APE like the third group for a further 30 days. Phytochemical analysis of APE indicated the presence of peonidin 3-O-glucoside cation, vitexin, rutin, thiamine, choline, tamarixetin, hyperoside, astragalin, and quercetin. The latter has been elucidated using one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR) and liquid chromatography–mass spectrometry (LC–MS-MS). Lead acetate increased the serum levels of alanine and aspartate aminotransferases and that of urea, creatinine, tumor necrosis factor alpha, and interleukin 1β, hepatic tissue malondialdehyde contents, and caspase 3 protein expression, as well as altering the hepatic tissue architecture. However, it decreased the serum levels of interleukin 10 and glutathione (GSH) contents, and the activities of catalase and superoxide dismutase in hepatic tissue. In contrast, the administration of APE ameliorated the lead-induced alterations in liver function and structure, exemplifying the benefits of Azolla’s phytochemical contents. Collectively, A. pinnate extract is a protective and curative agent against lead-induced hepatotoxicity via its antioxidant, anti-inflammatory, and anti-apoptotic impacts.

Astragalin Attenuates Dextran Sulfate Sodium (DSS)-Induced Acute Experimental Colitis by Alleviating Gut Microbiota Dysbiosis and Inhibiting NF-κB Activation in Mice

With the ulcerative colitis (UC) incidence increasing worldwide, it is of great importance to prevent and treat UC. However, efficient treatment options for UC are relatively limited. Due to the potentially serious adverse effects of existing drugs, there is an increasing demand for alternative candidate resources derived from natural and functional foods. Astragalin (AG) is a type of anti-inflammatory flavonoid, with Moringa oleifera and Cassia alata being its main sources. In this study, we investigated the therapeutic effects of AG on mice with dextran sulfate sodium (DSS)-induced colitis. Our results suggested that AG treatment reduced weight loss and the disease activity index (DAI), prevented colon shortening and alleviated colonic tissue damage. AG treatment reduced the expression of pro-inflammatory cytokines and related mRNAs (such as TNF-α, IL-6, and IL-1β), inhibited colonic infiltration by macrophages and neutrophils, ameliorated metabolic endotoxemia, and improved intestinal mucosal barrier function (increased expression levels of mRNAs such as ZO-1, occludin, and Muc2). Western blot analysis revealed that AG downregulated the NF-κB signaling pathway. Moreover, AG treatment partially reversed the alterations in the gut microbiota in colitis mice, mainly by increasing the abundance of potentially beneficial bacteria (such as Ruminococcaceae) and decreasing the abundance of potentially harmful bacteria (such as Escherichia-Shigella). Ruminococcaceae and Enterobacteriaceae (Escherichia-Shigella) were thought to be the key groups affected by AG to improve UC. Therefore, AG might exert a good anti-UC effect through microbiota/LPS/TLR4/NF-kB-related pathways in mice. The results of this study reveal the anti-inflammatory effect and mechanism of AG and provide an important reference for studying the mechanisms of natural flavonoids involved in preventing inflammation-driven diseases.

Astragalin attenuates oxidative stress and acute inflammatory responses in carrageenan-induced paw edema in mice

Astragalin is a flavonoid existed in several edible and medicinal plants and was recorded to have multiple biological and pharmacological significances. This work aimed to assess the possible protective effect of astragalin administration against oxidative tension, acute inflammation and histopathological deformations in a mouse paw edema model induced following intra sub-plantar injection of carrageenan. Thirty-six male Swiss mice were divided into four groups: control, carrageenan, astragalin (75 mg/kg) + carrageenan, and indomethacin (10 mg/kg) + carrageenan. Astragalin administration for five consecutive days to carrageenan injected mice showed a significant reduction in the development of paw in a time dependent effect, inhibited lipoperoxidation by-product, malondialdehyde and increased superoxide dismutase and catalase activities. Astragalin was found also to suppress the inflammatory signaling in the inflamed tissue as exhibited by the decreased myeloperoxidase activity along with the decreased protein and transcriptional level of pro-inflammatory cytokines including tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6. Moreover, inducible nitric oxide synthase and cyclooxygenase-2 expressions and their products (nitric oxide and prostaglandin E2) were downregulated. Additionally, astragalin decreased monocyte chemoattractant protein-1 and nuclear factor kappa B expression in the inflamed paw tissue. The recorded findings provide evidences for the potential application of astragalin as a plant-derived remedy for the treatment of acute inflammation due to its promising antioxidant and anti-inflammatory activities along with its ameliorative impact against the histopathological changes in the paw tissue.

Astragalin alleviates cerebral ischemia-reperfusion injury by improving anti-oxidant and anti-inflammatory activities and inhibiting apoptosis pathway in rats

BACKGROUND

Astragalin (AG), a flavonoid from many traditional herbs and medicinal plants, has been described to exhibit in vitro anti-inflammatory activity. The paper aimed to study the effects of astragalin on anti-inflammatory, anti-oxidative ability and apoptosis signaling pathway in brain tissue of rats with cerebral ischemia-reperfusion injury, and to explore its possible mechanism.

METHODS

The rat model of focal cerebral ischemia-reperfusion injury was established by suture method. It was randomly divided into 5 groups, sham operation group, ischemia-reperfusion (I/R) treatment group, and astragalin treatment I / R group (12.5, 25, 50 mg / kg). After 24 h of reperfusion, the neurological deficits of the rats were analyzed and HE staining was performed. The volume of cerebral infarction was calculated by triphenyltetrazolium chloride (TTC) staining, and the apoptosis of nerve cells was detected by TUNEL staining. In addition, the content of malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), glutathione (GSH) assay and glutathione peroxidase (GSH-Px) were measured in rat brain tissue. Western blot analysis was used to determine the expression of related proteins.

RESULTS

Compared with I/R group, the neurological deficit score and infarct volume of I/R rats were reduced in the astragalin treatment group. In the astragalin treatment group, MDA and NO levels in I/R rats were reduced, antioxidant enzymes and superoxide dismutase (SOD) activity were increased. In the astragalin treatment group, NF-κB (p65) and cyclooxygenase-2 (COX-2) expression levels were down-regulated, NF-E2-related factor 2 (Nrf2) nucleus and heme oxygenase-1 (HO-1) protein expression levels were up-regulated. In addition, the astragalin treatment can inhibit apoptosis, down-regulate Bax and cleaved caspase-3 expression, up-regulate Bcl-Xl expression.

CONCLUSION

The antioxidant properties of astragalin may play an important role in improving cerebral ischemia-reperfusion injury.

Optimization of Extraction Conditions of Phytochemical Compounds and Anti-Gout Activity of Euphorbia hirta L. (Ara Tanah) Using Response Surface Methodology and Liquid Chromatography-Mass Spectrometry (LC-MS) Analysis

Gout is a common disease affected most of the people due to the elevation of uric acid in the blood. Flavonoid and phenolic compounds are reported to exert the anti-gout activity of medicinal plants. Hence, this study aimed at optimizing the extraction conditions of phenolic and flavonoid compounds as well as the anti-gout (xanthine oxidase inhibitory activity) in vitro of Euphorbia hirta using response surface methodology (RSM). The plant part used was the whole plant excluding roots. The effects of three independent variables (extraction time, X ₁; extraction temperature, X ₂; and solid-to-liquid ratio, X ₃) on three response variables (total flavonoid content, Y ₁; total phenolic content, Y ₂; and xanthine oxidase inhibitory activity, Y ₃) were determined using central composite design (CCD) while phytochemical profiling of the extracts was determined by liquid chromatography-mass spectrometry (LC-MS). Quadratic models produced a satisfactory fitting of the experimental data with regard to total flavonoid content (r ² = 0.9407, p < 0.0001), total phenolic content (r ² = 0.9383, p < 0.0001), and xanthine oxidase inhibitory activity (r ² = 0.9794, p < 0.0001). The best extraction conditions observed for total flavonoid content, total phenolic content, and xanthine oxidase inhibitory activity were at a temperature of 79.07°C for 17.42 min with solid-to-liquid ratio of 1 : 20 g/ml. The optimum values for total flavonoid, total phenolic, and xanthine oxidase inhibitory activity were 67.56 mg RE/g, 155.21 mg GAE/g, and 91.42%, respectively. The main phytochemical compounds in the optimized E. hirta extract are neochlorogenic acid, quercetin-3β-D-glucoside, syringic acid, caffeic acid, ellagic acid, astragalin, afzelin, and quercetin. As conclusion, this study clearly demonstrated the best conditions to obtain higher xanthine oxidase inhibitory activity and phytochemical compounds which can be further used for the development of anti-gout agents.

Modulation of cell signaling pathways by Phyllanthus amarus and its major constituents: potential role in the prevention and treatment of inflammation and cancer

The causal and functional connection between inflammation and cancer has become a subject of much research interest. Modulation of cell signaling pathways, such as those involving mitogen activated protein kinases (MAPKs), nuclear factor kappa β (NF-κB), phosphatidylinositol 3-kinase and protein kinase B (PI3K/Akt), and Wnt, and their outcomes play a fundamental role in inflammation and cancer. Activation of these cell signaling pathways can lead to various aspects of cancer-related inflammation. Hence, compounds able to modulate inflammation-related molecular targets are sought after in anticancer drug development programs. In recent years, plant extracts and their metabolites have been documented with potential in the prevention and treatment of cancer and inflammatory ailments. Plants possessing anticancer and anti-inflammatory properties due to their bioactive constituents have been reported to modulate the molecular and cellular pathways which are related to inflammation and cancer. In this review we focus on the flavonoids (astragalin, kaempferol, quercetin, rutin), lignans (phyllanthin, hypophyllanthin, and niranthin), tannins (corilagin, geraniin, ellagic acid, gallic acid), and triterpenes (lupeol, oleanolic acid, ursolic acid) of Phyllanthus amarus, which exert various anticancer and anti-inflammatory activities via perturbation of the NF-κB, MAPKs, PI3K/Akt, and Wnt signaling networks. Understanding the underlying mechanisms involved may help future research to develop drug candidates for prevention and new treatment for cancer and inflammatory diseases.

Astragalin Suppresses Inflammatory Responses and Bone Destruction in Mice With Collagen-Induced Arthritis and in Human Fibroblast-Like Synoviocytes

Astragalin, as a bioactive flavonoid with anti-inflammatory, antioxidant, and protective properties, provides a potential agent for rheumatoid arthritis (RA). In this study, its therapeutic efficacy and the underlying mechanisms were explored using DBA/1J mice with collagen-induced arthritis (CIA). It was demonstrated that astragalin could significantly attenuate inflammation of CIA mice. The effects were associated with decreased severity of arthritis (based on the arthritis index), joint swelling and reduced bone erosion and destruction. Furthermore, astragalin treatment suppressed the production of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8), and inhibited the expression of matrix metalloproteinases (MMP-1, MMP-3, and MMP-13) in chondrocytes and synovial cells of CIA mice. Fibroblast-like synoviocytes derived from RA patients (MH7A cells) were applied to verify these effects. In vitro, astragalin inhibited the expression of matrix metalloproteinases (MMP-1, MMP-3, and MMP-13) dose-dependently in TNF-α-induced MH7A cells, with no apparent cytotoxicity. Furthermore, astragalin suppressed the phosphorylation of p38, JNK, and the activation of c-Jun/AP-1 in TNF-α-induced MH7A cells. In conclusion, it has proven that astragalin could attenuate synovial inflammation and joint destruction in RA at least partially by restraining the phosphorylation of MAPKs and the activating of c-Jun/AP-1. Therefore, astragalin can be a potential therapeutic agent for RA.

Astragalin Promotes Osteoblastic Differentiation in MC3T3-E1 Cells and Bone Formation in vivo

Astragalin (AG) is a biologically active flavonoid compound that can be extracted from a number of medicinal plants. However, the effects of AG on osteoblastic differentiation in mouse MC3T3-E1 cells and on bone formation in vivo have not been studied fully. In this study, we found that the activities of alkaline phosphatase (ALP) and mineralized nodules in MC3T3-E1 cells were both significantly increased after treatment with AG (5, 10, and 20 μM). Meanwhile, the mRNA and protein levels of osteoblastic marker genes in MC3T3-E1 cells after AG treatment were markedly increased compared with a control group. In addition, the levels of BMP-2, p-Smad1/5/9, and Runx2 were significantly elevated in AG-treated MC3T3-E1 cells. Moreover, we found that the protein levels of Erk1/2, p-Erk1/2, p38, p-p38, and p-JNK were also significantly increased in AG-treated MC3T3-E1 cells compared to those in the control group. Finally, in vivo experiments demonstrated that AG significantly promoted bone formation in an ovariectomized (OVX)-induced osteoporotic mouse model. This was evidenced by significant increases in the values of osteoblast-related parameters (BFR/BS, MAR, Ob.S/BS, and Ob.N/B.Pm) and bone histomorphometric parameters (BMD, BV/TV, Tb.Th, and Tb.N.) in OVX mice after AG treatment (5, 10, and 20 mg/kg). Collectively, these results demonstrated that AG may promote osteoblastic differentiation in MC3T3-E1 cells via the activation of the BMP and MAPK pathways and promote bone formation in vivo. These novel findings indicated that AG may be a useful bone anabolic agent for the prevention and treatment of osteoporosis.

Protective effects of Astragalin on spermatogenesis in streptozotocin-induced diabetes in male mice by improving antioxidant activity and inhibiting inflammation

Spermatogenic dysfunction is a common complication in men with diabetes and is the most important manifestation of diabetes-related male reproduction damage. Astragalin (AG) is one of the main flavonoids from Cuscuta chinensis, which has rich pharmacological activities. This study aimed to establish whether AG may contribute to the recovery from spermatogenic dysfunction. AG (3.3, 10 and 30 mg/kg) and Clomiphene (5 mg/kg) were orally administered to streptozotocin-induced diabetic male mice for 8 weeks. After the experiments performed, reproductive organs, sperm parameters and histomorphological changes were analysed. Antioxidant and anti-inflammatory capacity were estimated in testicular tissues. The results revealed that AG significantly improved the reproductive organs, sperm parameters and testicular morphology to different degrees in diabetic mice. Nitric oxide (NO) and malondialdehyde (MDA) levels were significantly reduced, and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), markedly increased in the testicular tissue after AG was administered. Interestingly, AG also downregulated the protein expressions of tumour necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) in testes. In conclusion, AG is a potential beneficial agent to protect diabetic-induced spermatogenic dysfunction in male mice by increasing antioxidant enzymes activities and inhibiting inflammation.

Cow-to-mouse fecal transplantations suggest intestinal microbiome as one cause of mastitis

BACKGROUND

Mastitis, which affects nearly all lactating mammals including human, is generally thought to be caused by local infection of the mammary glands. For treatment, antibiotics are commonly prescribed, which however are of concern in both treatment efficacy and neonate safety. Here, using bovine mastitis which is the most costly disease in the dairy industry as a model, we showed that intestinal microbiota alone can lead to mastitis.

RESULTS

Fecal microbiota transplantation (FMT) from mastitis, but not healthy cows, to germ-free (GF) mice resulted in mastitis symptoms in mammary gland and inflammations in serum, spleen, and colon. Probiotic intake in parallel with FMT from diseased cows led to relieved mastitis symptoms in mice, by shifting the murine intestinal microbiota to a state that is functionally distinct from either healthy or diseased microbiota yet structurally similar to the latter. Despite conservation in mastitis symptoms, diseased cows and mice shared few mastitis-associated bacterial organismal or functional markers, suggesting striking divergence in mastitis-associated intestinal microbiota among lactating mammals. Moreover, an "amplification effect" of disease-health distinction in both microbiota structure and function was apparent during the cow-to-mouse FMT.

CONCLUSIONS

Hence, dysbiosis of intestinal microbiota may be one cause of mastitis, and probiotics that restore intestinal microbiota function are an effective and safe strategy to treat mastitis.

Astragalin: A Bioactive Phytochemical with Potential Therapeutic Activities

Natural products, an infinite treasure of bioactive chemical entities, persist as an inexhaustible resource for discovery of drugs. This review article intends to emphasize on one of the naturally occurring flavonoids, astragalin (kaempferol 3-glucoside), which is a bioactive constituent of various traditional medicinal plants such as Cuscuta chinensis. This multifaceted compound is well known for its diversified pharmacological applications such as anti-inflammatory, antioxidant, neuroprotective, cardioprotective, antiobesity, antiosteoporotic, anticancer, antiulcer, and antidiabetic properties. It carries out the aforementioned activities by the regulation and modulation of various molecular targets such as transcription factors (NF-κB, TNF-α, and TGF-β1), enzymes (iNOS, COX-2, PGE2, MMP-1, MMP-3, MIP-1α, COX-2, PGE-2, HK2, AChe, SOD, DRP-1, DDH, PLCγ1, and GPX), kinases (JNK, MAPK, Akt, ERK, SAPK, IκBα, PI3K, and PKCβ2), cell adhesion proteins (E-cadherin, vimentin PAR-2, and NCam), apoptotic and antiapoptotic proteins (Beclin-1, Bcl-2, Bax, Bcl-xL, cytochrome c, LC3A/B, caspase-3, caspase-9, procaspase-3, procaspase-8, and IgE), and inflammatory cytokines (SOCS-3, SOCS-5, IL-1β, IL-4, IL-6, IL-8, IL-13, MCP-1, CXCL-1, CXCL-2, and IFN-γ). Although researchers have reported multiple pharmacological applications of astragalin in various diseased conditions, further experimental investigations are still mandatory to fully understand its mechanism of action. It is contemplated that astragalin could be subjected to structural optimization to ameliorate its chemical accessibility, to optimize its absorption profiles, and to synthesize its more effective analogues which will ultimately lead towards potent drug candidates.

Astragalin-induced cell death is caspase-dependent and enhances the susceptibility of lung cancer cells to tumor necrosis factor by inhibiting the NF-кB pathway

Flavonoids are naturally occurring polyphenolic compounds and are among the most promising anticancer agents. Here, we demonstrate that the flavonoid astragalin (AG), also known as kaempferol-3-O-β-D-glucoside, induces cell death. This was prevented by the caspase inhibitors z-DEVD-FMK and z-LEHD-FMK. AG-induced cell death was associated with an increase in the Bax:Bcl-2 ratio and amplified by the inhibition of extracellular signal-regulated kinase (ERK)-1/2 and Akt signaling. Meanwhile, AG suppressed LPS-induced NF-κB activation. Additional studies revealed that AG inhibited tumor necrosis factor-alpha (TNFα)-induced NF-κB activity. AG also potentiated TNFα-induced apoptosis in A549 cells. Furthermore, using a mouse xenograft model, we demonstrated that AG suppressed tumor growth and induced cancer cell apoptosis in vivo. Taken together, these results suggest that AG may be a promising cancer therapeutic drug that warrants further investigation into its potential clinical applications.

Quercetin decrease somatic cells count in mastitis of dairy cows

Quercetin is a dietary flavonoid which has an effect on inflammation, angiogenesis and vascular inflammation. In several other flavonoids (e.g. kaempferol, astragalin, alpinetin, baicalein, indirubin), anti-inflammatory mechanism was proven by using mice mastitis model. The aim of the current study was pilot analysis of quercetin tolerability and its impact on somatic cells count (SCC) after multiple intramammary treatment on dairy cows with clinical mastitis. Based on SCC and clinical investigation, 9 dairy cows with clinical mastitis of one quarter were selected for the pilot study. Baseline analysis (hematology, TNFα, SCC) was performed every 24h among all cows three days before the first dose (B1-B3). After the baseline monitoring (B1-B3) eight days treatment (D1-D8) was performed with a high and low dose. Selected blood parameters were analyzed. Starting from D1 to D8, a decrease of SCC in relation to baseline was characterized by declining trend. The presented results allowed the confirmation of the significant influence of quercetin on the reduction of SCC in mastitis in dairy cows after 8days of therapy.

Apoptotic Effect of Astragalin in Melanoma Skin Cancers via Activation of Caspases and Inhibition of Sry-related HMg-Box Gene 10

Though Astragalin (kaempferol-3-glucoside) contained in Paeonia lactiflora and other plants was known to have anti-oxidant, antiinflammatory, and anti-tumor activity, the anti-tumor mechanism of Astragalin has never been reported in melanomas until now. Thus, in the present study, the underlying apoptotic mechanism of Astragalin isolated from Aceriphyllum rossii was elucidated in A375P and SK-MEL-2 melanoma cells. Astragalin exerted cytotoxicity in A375P and SK-MEL-2 cells in a concentration-dependent manner. Also, Astragalin significantly increased the number of TdT-mediated dUTP nick end labeling positive cells and sub-G1 population as a feature of apoptosis in A375P and SK-MEL-2 cells compared with untreated control. Consistently, western blotting revealed that Astragalin activated caspase 9/3 and Bax, cleaved poly (ADP-ribose) polymerase, and attenuated the expression of cyclin D1, Mcl-1, and Sry-related HMg-Box gene 10 (SOX10) in A375P and SK-MEL-2 cells. Of note, ectopic expression of SOX10 reduced the apoptotic ability of Astragalin to inhibit proliferation, cleave poly (ADP-ribose) polymerase, and caspase 3 in A375P and SK-MEL-2 melanoma cells. Overall, our findings provide evidence that Astragalin induces apoptosis in A375P and SK-MEL-2 melanoma cells via activation of caspase9/3 and inhibition of SOX10 signaling. Copyright © 2017 John Wiley & Sons, Ltd.

RAW REHMANNIA RADIX POLYSACCHARIDE CAN EFFECTIVELY RELEASE PEROXIDATIVE INJURY INDUCED BY DUCK HEPATITIS A VIRUS

Background:

Duck viral hepatitis (DVH), caused by duck hepatitis A virus (DHAV), is a fatal contagious infectious disease which spreads rapidly with high morbidity and high mortality, and there is no effective clinical drug against DVH.

Materials and Methods:

Raw Rehmannia Radix Polysaccharide (RRRP), Lycii Fructus polysaccharides and Astragalus Radix polysaccharides were experimented in vitro and in vivo. Mortality rate, livers change, liver lesion scoring, peroxidative injury evaluation indexes in vitro and in vivo, and hepatic injury evaluation indexes of optimal one were detected and observed in this experiment.

Results:

RRRP could reduce mortality with the protection rate about 20.0% compared with that of the viral control (VC) group, finding that RRRP was the most effective against DHAV. The average liver scoring of the VC, blank control (BC), RRRP groups were 3.5, 0, 2.1. Significant difference (P<0.05) appeared between any two groups, demonstrating that it can alleviate liver pathological change. RRRP could make the hepatic injury evaluation indexes similar to BC group while the levels of the VC group were higher than other two groups in general. The levels of SOD, GSH-Px, CAT of RRRP group showed significant higher than that of VC group while the levels of NOS and MDA showed the opposite tendency, thus, RRRP could release peroxidative injury.

Conclusion:

RRRP was the most effective against duck hepatitis A virus (DHAV). RRRP could reduce mortality, alleviate liver pathological change, down-regulate liver lesion score, release peroxidative injury and hepatic injury. The antiviral and peroxidative injury releasing activity of RRRP for DHAV provided a platform to test novel drug strategies for hepatitis A virus in human beings.

Andrographolide Inhibits Inflammatory Cytokines Secretion in LPS-Stimulated RAW264.7 Cells through Suppression of NF-κB/MAPK Signaling Pathway

Andrographolide, the main active component extracted from Andrographis paniculata (Burm.f.) Wall. ex Nees, exerts anti-inflammatory effects; however, the principal molecular mechanisms remain unclear. The objective of this study was to investigate the molecular mechanisms of Andrographolide in modifying lipopolysaccharide- (LPS-) induced signaling pathway in RAW264.7 cells. An in vitro model of inflammation was induced by LPS in mouse RAW264.7 cells in the presence of Andrographolide. The concentration and expression levels of proinflammatory cytokines were determined by an enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. The nuclear level of NF-κB was measured by an electrophoretic mobility shift assay (EMSA). The expression levels of NF-κB, p38, ERK, and JNK were determined by western blot. Andrographolide dose-dependently inhibited the release and mRNA expression of TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells. The nuclear level of p65 protein was decreased in Andrographolide treatment group. Western blot analysis showed that Andrographolide suppressed LPS-induced NF-κB activation and the phosphorylation of IkBa, ERK1/2, JNK, and p38. These results suggest that Andrographolide exerts an anti-inflammatory effect by inhibiting the activation of NF-κB/MAPK signaling pathway and the induction of proinflammatory cytokines.

Inhibitory Effects of Emodin, Thymol, and Astragalin on Leptospira interrogans-Induced Inflammatory Response in the Uterine and Endometrium Epithelial Cells of Mice

Leptospirosis is a systemic infection that causes, among others, acute kidney injury, acute liver disease, muscle pain, vasculitis, bleeding disorders, and reproductive loss. In an effort to reduce uterine inflammatory responses induced by Leptospira, we evaluated the anti-inflammation effects of emodin, thymol, and astragalin in a mouse model. Our results showed that treatment with emodin, thymol, and astragalin alleviated uterine inflammation induced by leptospira infection via suppression of pro-inflammatory cytokine expression and prevented tissue damage. Furthermore, we used primary endometrium epithelial cells to show that treatment with these chemicals inhibited the expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 using enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. Western blot results showed that these chemicals suppressed the phosphorylation of p38, p65, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. These results indicate that treatment with emodin, thymol, and astragalin suppressed inflammatory response by regulating NF-κB and mitogen-activated protein kinase signaling pathways in leptospira-infected uterine and endometrium epithelial cells of mice.

Astragalin Inhibits Allergic Inflammation and Airway Thickening in Ovalbumin-Challenged Mice

Lung inflammation and oxidative stress are the major contributors to the development of obstructive pulmonary diseases. Macrophages are involved in pulmonary inflammation and alveolar damage in emphysema. Astragalin is an anti-inflammatory flavonoid present in persimmon leaves and green tea seeds. This study elucidated that astragalin inhibited inflammatory cell infiltration induced by 20 μM H₂O₂ and blocked airway thickening and alveolar emphysema induced by 20 μg of ovalbumin (OVA) in mice. OVA induced mouse pulmonary MCP-1, and H₂O₂ enhanced the expression of MCP-1/ICAM-1/αv integrin in bronchial airway epithelial BEAS-2B cells. Such induction was inhibited by supplying 10-20 mg/kg of astragalin to OVA-challenged mice and 1-20 μM astragalin to oxidant-stimulated cells. Oral administration of 20 mg/kg of astragalin reduced the induction of F4/80/CD68/CD11b in airways of mice challenged with OVA. Additionally, emphysema tissue damage was observed in OVA-exposed alveoli. Mast cell recruitment in the airway subepithelium was blocked by supplementing astragalin to OVA-challenged mice. Orally treating 20 mg/kg of astragalin reduced α-SMA induction in inflammation-occurring airways and appeared to reverse airway thickening and constriction induced by an OVA episode. These results revealed that astragalin may improve airway thickening and alveolar destruction with blockade of allergic inflammation in airways. Therefore, astragalin may be a therapeutic agent antagonizing asthma and obstructive pulmonary diseases.

Indirubin Treatment of Lipopolysaccharide-Induced Mastitis in a Mouse Model and Activity in Mouse Mammary Epithelial Cells

Indirubin is a Chinese medicine extracted from indigo and known to be effective for treating chronic myelogenous leukemia, neoplasia, and inflammatory disease. This study evaluated the in vivo anti-inflammatory activity of indirubin in a lipopolysaccharide- (LPS-) induced mouse mastitis model. The indirubin mechanism and targets were evaluated in vitro in mouse mammary epithelial cells. In the mouse model, indirubin significantly attenuated the severity of inflammatory lesions, edema, inflammatory hyperemia, milk stasis and local tissue necrosis, and neutrophil infiltration. Indirubin significantly decreased myeloperoxidase activity and downregulated the production of tumor necrosis factor-α, interleukin-1β (IL-1β), and IL-6 caused by LPS. In vitro, indirubin inhibited LPS-stimulated expression of proinflammatory cytokines in a dose-dependent manner. It also downregulated LPS-induced toll-like receptor 4 (TLR4) expression and inhibited phosphorylation of LPS-induced nuclear transcription factor-kappa B (NF-κB) P65 protein and inhibitor of kappa B. In addition to its effect on the NF-κB signaling pathway, indirubin suppressed the mitogen-activated protein kinase (MAPK) signaling by inhibiting phosphorylation of extracellular signal-regulated kinase (ERK), P38, and c-jun NH2-terminal kinase (JNK). Indirubin improved LPS-induced mouse mastitis by suppressing TLR4 and downstream NF-κB and MAPK pathway inflammatory signals and might be a potential treatment of mastitis and other inflammatory diseases.

Recent developments in the role of reactive oxygen species in allergic asthma

Allergic asthma has a global prevalence, morbidity, and mortality. Many environmental factors, such as pollutants and allergens, are highly relevant to allergic asthma. The most important pathological symptom of allergic asthma is airway inflammation. Accordingly, the unique role of reactive oxygen species (ROS) had been identified as a main reason for this respiratory inflammation. Many studies have shown that inhalation of different allergens can promote ROS generation. Recent studies have demonstrated that several pro-inflammatory mediators are responsible for the development of allergic asthma. Among these mediators, endogenous or exogenous ROS are responsible for the airway inflammation of allergic asthma. Furthermore, several inflammatory cells induce ROS and allergic asthma development. Airway inflammation, airway hyper-responsiveness, tissue injury, and remodeling can be induced by excessive ROS production in animal models. Based on investigations of allergic asthma and ROS formation mechanisms, we have identified several novel anti-inflammatory therapeutic treatments. This review describes the recent data linking ROS to the pathogenesis of allergic asthma.

Engeletin Alleviates Lipopolysaccharide-Induced Endometritis in Mice by Inhibiting TLR4-mediated NF-κB Activation

Engeletin (dihydrokaempferol 3-rhamnoside) is a flavanonol glycoside. It can be found in the skin of white grapes and white wine and is widely distributed in southeast Asia, and the leaves are used in a tea. Here, we explored the impact of engeletin against the inflammatory reaction in a lipopolysaccharide (LPS)-induced endometritis mouse model. Engeletin treatment significantly attenuated uterus damage and decreased myeloperoxidase activity. ELISA and qPCR assays showed that engeletin dose-dependently suppressed the expression of TNF-α, IL-1β, and IL-6. Molecular studies also demonstrated that the levels of iNOS, COX-2, and TLR4, along with their downstream molecules MyD88, IRAK1, TRAF6, and TAK1, were also suppressed by engeletin. In addition, engeletin treatment inhibited NF-κB signaling-pathway activation. Moreover, immunofluorescence analysis demonstrated that engeletin suppressed NF-κB-p65 nuclear translocation. These data indicated the protective action of engeletin against LPS-stimulated endometritis in mice via negative regulation of pro-inflammatory mediators via the TLR4-regulated NF-κB pathway.

Astragalin, a Flavonoid from Morus alba (Mulberry) Increases Endogenous Estrogen and Progesterone by Inhibiting Ovarian Granulosa Cell Apoptosis in an Aged Rat Model of Menopause

BACKGROUND

To determine the mechanism by which the flavonoid glycoside astragalin (AST) reduces ovarian failure in an aged rat model of menopause.

METHODS

The in vivo effect of AST on granulosa cell (GC) apoptosis in aged female rats was determined using flow cytometry. In vitro, the effects of AST on cultured GCs were investigated using the MTT proliferation assay and western blot assays.

RESULTS

Aged rats had significantly higher GC apoptosis as compared with young female rats. Treatment of aged rats with AST (all three doses; p < 0.01) or Progynova (p < 0.01) significantly reduced GC apoptosis as compared with the aged controls. The proportions of total apoptotic GCs was 25.70%, 86.65%, 47.04%, 27.02%, 42.09% and 56.42% in the normal, aged, 17β-estradiol (E₂), high dose AST, medium dose AST, and low dose AST-treated groups, respectively. Significant increases of serum E₂ and P₄ levels, as well as altered levels of serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels. In cultured rat GCs, AST stimulated GC proliferation, E₂ and progesterone (P₄) secretion, reduced apoptosis, reduced the level of the pro-apoptotic protein Bcl-2 (p < 0.01), but had no effect on BAX.

CONCLUSIONS

AST enhanced ovarian function in aged female rats by increasing E₂ and P₄ levels, and reducing ovarian GC apoptosis via a mechanism involving Bcl-2. These data demonstrate a new pharmacological activity for AST, as well as a novel mechanism of action, and further suggest that AST may be a new therapeutic agent for the management of menopausal symptoms.

Bergenin Plays an Anti-Inflammatory Role via the Modulation of MAPK and NF-κB Signaling Pathways in a Mouse Model of LPS-Induced Mastitis

Mastitis is a major disease in humans and other animals and is characterized by mammary gland inflammation. It is a major disease of the dairy industry. Bergenin is an active constituent of the plants of genus Bergenia. Research indicates that bergenin has multiple biological activities, including anti-inflammatory and immunomodulatory properties. The objective of this study was to evaluate the protective effects and mechanism of bergenin on the mammary glands during lipopolysaccharide (LPS)-induced mastitis. In this study, mice were treated with LPS to induce mammary gland mastitis as a model for the disease. Bergenin treatment was initiated after LPS stimulation for 24 h. The results indicated that bergenin attenuated inflammatory cell infiltration and decreased the concentration of NO, TNF-α, IL-1β, and IL-6, which were increased in LPS-induced mouse mastitis. Furthermore, bergenin downregulated the phosphorylation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinases (MAPK) signaling pathway proteins in mammary glands with mastitis. In conclusion, bergenin reduced the expression of NO, TNF-α, IL-1β, and IL-6 proinflammatory cytokines by inhibiting the activation of the NF-κB and MAPKs signaling pathways, and it may represent a novel treatment strategy for mastitis.

Bovine mastitis may be associated with the deprivation of gut Lactobacillus

Bovine mastitis is an economical important microbial disease in dairy industry. Some recent human clinical trials have shown that oral probiotics supplementation could effectively control clinical mastitis, suggesting that the mechanism of mastitis protection might be achieved via the host gut microbiota. We aimed to test our hypothesis that bovine mastitis was related to changes in both the mammary and gut microbial profiles. By quantitative PCR, the milk and faecal microbial profiles of cows with low (<3×10⁵ cells/ml) and high (>1×10⁶ cells/ml) somatic cell count (SCC) were compared. Firstly, we observed drastic differences in both the milk and faecal microbial compositions at genus and Lactobacillus-species levels between the two groups. Secondly, the pattern of faecal microbial community changes of mastitis cows was similar to that of the milk, characterised by a general increase in the mastitis pathogens (Enterococcus, Streptococcus and Staphylococcus) and deprivation of Lactobacillus and its members (L. salivarius, L. sakei, L. ruminis, L. delbrueckii, L. buchneri, and L. acidophilus). Thirdly, only the faecal lactobacilli, but not bifidobacteria correlated with the milk microbial communities and SCC. Our data together hint to a close association between bovine mastitis, the host gut and milk microbiota.

Geniposide plays an anti-inflammatory role via regulating TLR4 and downstream signaling pathways in lipopolysaccharide-induced mastitis in mice

Geniposide is a medicine isolated from Gardenia jasminoides Ellis, which is a traditional Chinese herb that is widely used in Asia for the treatment of inflammation, brain diseases, and hepatic disorders. Mastitis is a highly prevalent and important infectious disease. In this study, we used a lipopolysaccharide (LPS)-induced mouse mastitis model and LPS-stimulated primary mouse mammary epithelial cells (mMECs) to explore the anti-inflammatory effect and the mechanism of action of geniposide. Using intraductal injection of LPS as a mouse model of mastitis, we found that geniposide significantly reduced the infiltration of inflammatory cells and downregulated the production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6). To further investigate the anti-inflammatory mechanism, we used LPS-stimulated mMECs as an in vitro mastitis model. The results of enzyme-linked immunosorbent assay (ELISA) and quantitative real-time polymerase chain reaction (qRT-PCR) showed that geniposide inhibited the expression of TNF-α, IL-1β, and IL-6 in a dose-dependent manner. Western blot analysis demonstrated that geniposide could suppress the phosphorylation of inhibitory kappa B (IκBα), nuclear factor-κB (NF-κB), p38, extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinase (JNK). Geniposide also inhibited the expression of toll-like receptor 4 (TLR4) in the LPS-stimulated mMECs. In conclusion, geniposide exerted its anti-inflammatory effect by regulating TLR4 expression, which affected the downstream NF-κB and mitogen-activated protein kinase (MAPK) signaling pathways. Thus, geniposide may be a potential drug for mastitis therapy.

Astragalin inhibits autophagy-associated airway epithelial fibrosis

Background

Fibrotic remodeling of airway and lung parenchymal compartments is attributed to pulmonary dysfunction with an involvement of reactive oxygen species (ROS) in chronic lung diseases such as idiopathic pulmonary fibrosis and asthma.

Methods

The in vitro study elucidated inhibitory effects of astragalin, kaempferol-3-O-glucoside from leaves of persimmon and green tea seeds, on oxidative stress-induced airway fibrosis. The in vivo study explored the demoting effects of astragalin on epithelial to mesenchymal transition in BALB/c mice sensitized with ovalbumin (OVA).

Results

The exposure of 20 μM H₂O₂ for 72 h accelerated E-cadherin loss and vimentin induction in airway epithelial BEAS-2B cells, which was reversed by non-toxic astragalin at 1–20 μM. Astragalin allayed the airway tissue levels of ROS and vimentin enhanced by OVA challenge. Collagen type 1 production increased in H₂O₂–exposed epithelial cells and collagen fiber deposition was observed in OVA-challenged mouse airways. This study further investigated that the oxidative stress-triggered autophagic regulation was responsible for inducing airway fibrosis. H₂O₂ highly enhanced the expression induction of the autophagy-related beclin-1 and light chains 3A/B (LC3A/B) within 4 h and astragalin blocked such induction by H₂O₂. This compound deterred the ROS-promoted autophagosome formation in BEAS-2B cells. Consistently, in OVA-sensitized mice the expression of beclin-1 and LC3A/B was highly induced, and oral administration of astragalin suppressed the autophagosome formation with inhibiting the induction of these proteins in OVA-challenged airway subepithelium. Induction of autophagy by spermidine influenced the epithelial induction of E-cadherin and vimentin that was blocked by treating astragalin.

Conclusion

These results demonstrate that astragalin can be effective in allaying ROS-promoted bronchial fibrosis through inhibiting autophagosome formation in airways.

Astragalin inhibits IL-1β-induced inflammatory mediators production in human osteoarthritis chondrocyte by inhibiting NF-κB and MAPK activation

Astragalin, a bioactive component isolated from Rosa agrestis, has been described to exhibit anti-inflammatory activity. The aim of this study was to investigate the anti-inflammatory effects and the underlying mechanisms of astragalin on IL-1β-stimulated human osteoarthritis chondrocyte. The production of NO and PGE2 was detected by Griess reaction and ELISA. The expression of iNOS and COX-2 was detected by western blotting. The expression of NF-κB and MAPKs was detected by western blot analysis. We found that astragalin dose-dependently inhibited IL-1β-induced NO and PGE2 production, as well as iNOS and COX-2 expression. Meanwhile, western blot analysis showed that astragalin inhibited IL-1β-induced NF-κB and MAPK activation in human osteoarthritis chondrocyte. In addition, astragalin was found to activate PPAR-γ. The inhibition of astragalin on IL-1β-induced NO and PGE2 production can be reversed by PPAR-γ antagonist GW9662. Astragalin suppressed IL-1β-induced inflammatory mediators via activating PPAR-γ, which subsequently inhibited IL-1β-induced NF-κB and MAPK activation. Astragalin may be a potential agent in the treatment of osteoarthritis.

Non-classical proIL-1beta activation during mammary gland infection is pathogen-dependent but caspase-1 independent

Infection of the mammary gland with live bacteria elicits a pathogen-specific host inflammatory response. To study these host-pathogen interactions wild type mice, NF-kappaB reporter mice as well as caspase-1 and IL-1beta knockout mice were intramammarily challenged with Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The murine mastitis model allowed to compare the kinetics of the induced cytokine protein profiles and their underlying pathways. In vivo and ex vivo imaging showed that E. coli rapidly induced NF-kappaB inflammatory signaling concomitant with high mammary levels of TNF-alpha, IL-1 alpha and MCP-1 as determined by multiplex analysis. In contrast, an equal number of S. aureus bacteria induced a low NF-kappaB activity concomitant with high mammary levels of the classical IL-1beta fragment. These quantitative and qualitative differences in local inflammatory mediators resulted in an earlier neutrophil influx and in a more extensive alveolar damage post-infection with E. coli compared to S. aureus. Western blot analysis revealed that the inactive proIL-1beta precursor was processed into pathogen-specific IL-1beta fragmentation patterns as confirmed with IL-1beta knockout animals. Additionally, caspase-1 knockout animals allowed to investigate whether IL-1beta maturation depended on the conventional inflammasome pathway. The lack of caspase-1 did not prevent extensive proIL-1beta fragmentation by either of S. aureus or E. coli. These non-classical IL-1beta patterns were likely caused by different proteases and suggest a sentinel function of IL-1beta during mammary gland infection. Thus, a key signaling nodule can be defined in the differential host innate immune defense upon E. coli versus S. aureus mammary gland infection, which is independent of caspase-1.

Inhibitory effects of astragalin on lipopolysaccharide-induced inflammatory response in mouse mammary epithelial cells

BACKGROUND

Tea brewed from the leaves of persimmon or Rosa agrestis have several medical functions including treating allergy, antiatopic dermatitis, and anti-inflammatory effects. The objective of this study was to investigate the molecular mechanisms of astragalin, a main flavonoid component isolated from these herbs, in modifying lipopolysaccharide (LPS)-induced signaling pathways in primary cultured mouse mammary epithelial cells (mMECs).

MATERIALS AND METHODS

The mMECs were treated with LPS in the absence or presence of different concentrations of astragalin. The expression of proinflammatory cytokines tumor necrosis factor α, and interleukin 6, as well as nitric oxide production were determined by enzyme-linked immunosorbent assay and Griess reaction, respectively. Cyclooxygenase-2, inducible nitric oxide synthase, toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), inhibitor protein of NF-κB (IκBα), P38, extracellular signal-regulated kinase, and c-Jun N-terminal kinase were measured by Western blot.

RESULTS

The results showed that astragalin suppressed the expression of tumor necrosis factor α, interleukin 6, and nitric oxide in a dose-dependent manner in mMECs. Western blot results showed that the expression of inducible nitric oxide synthase and cyclooxygenase-2 was inhibited by astragalin. Besides, astragalin efficiently decreased LPS-induced TLR4 expression, NF-κB activation, IκBα degradation, and the phosphorylation of p38, extracellular signal-regulated kinase in BMECs.

CONCLUSIONS

Our results indicated that astragalin exerts anti-inflammatory properties possibly via the inactivation of TLR4-mediated NF-κB and mitogen-activated protein kinases signaling pathways in LPS-stimulated mMECs. Thus, astragalin may be a potential therapeutic agent for bovine mastitis.