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

S-allylmercaptocysteine inhibits TLR4-mediated inflammation through enhanced formation of inhibitory MyD88 splice variant in mammary epithelial cells

Mastitis is an inflammatory disease affecting mammary tissues caused by bacterial infection that negatively affects milk quality and quantity. S-Allylmercaptocysteine (SAMC), a sulfur compound in aged garlic extract (AGE), suppresses lipopolysaccharide (LPS)-induced inflammation in mouse models and cell cultures. However, the mechanisms underlying this anti-inflammatory effect remain unclear. In this study, we demonstrated that oral administration of AGE suppressed the LPS-induced immune response in a mastitis mouse model and that SAMC inhibited LPS-induced interleukin-6 production and nuclear factor κB p65 subunit activation in HC11 mammary epithelial cells. Global phosphoproteomic analysis revealed that SAMC treatment downregulated 910 of the 1,304 phosphorylation sites upregulated by LPS stimulation in mammary cells, including those associated with toll-like receptor 4 (TLR4) signaling. Additionally, SAMC decreased the phosphorylation of 26 proteins involved in pre-mRNA splicing, particularly the U2 small nuclear ribonucleoprotein complex. Furthermore, we found that SAMC increased the production of the myeloid differentiation factor 88 short form (MyD88-S), an alternatively spliced form of MyD88 that negatively regulates TLR4 signaling. These findings suggest that SAMC inhibits TLR4-mediated inflammation via alternative pre-mRNA splicing, thus promoting MyD88-S production in mammary epithelial cells. Therefore, SAMC may alleviate various inflammatory diseases, such as mastitis, by modulating immune responses.

Syndecan-3 inhibits LPS-induced Inflammation of Bovine Mammary Epithelial Cells through the NF-κB Signal Transduction Pathway

In mastitis, excessive inflammation caused by lipopolysaccharide (LPS) is an important factor leading to mammary tissue damage. Therefore, exploring the regulatory factors that can inhibit the widespread inflammation caused by LPS is crucial. Syndecan-3 (SDC3) has been found to play an active role in anti-inflammatory infection by inhibiting leukocyte adhesion, reducing the accumulation of inflammatory products, such as reactive oxygen species, and competing with chemokines; however, the role and regulatory mechanism of SDC3 in mastitis remains unknown. Therefore, this study aimed to reveal the effect of SDC3 on LPS-induced inflammation in bovine mammary epithelial cells (BMECs) and explore its possible molecular mechanisms. First, we constructed a BMEC inflammatory model. It was found that cells stimulated with 10 μg/mL LPS for 24 h strongly induced the expression of inflammatory cytokines and had no toxic effect on cells, which was the best condition to simulate the BMECs inflammatory response in vitro. Subsequently, we used overexpression and RNAi interference, Real Time Quantitative PCR (RT-qPCR), and Western blot assays to explore the effects of SDC3 on LPS-induced inflammatory factors and their mechanisms. The results showed that overexpression of SDC3 could inhibit the transcriptional levels of inflammatory cytokines IL-6, IL-1β, and TNFα induced by LPS and inhibit the activation of the NF-κB inflammatory pathway by inhibiting the expression of NF-κB p50 and p-IκBα and promoting the expression of IκBα. Our results suggest that SDC3 inhibits the LPS-induced inflammatory response of BMECs through the NF-κB pathway, in which NF-κB p50 may be an important target of SDC3. These findings lay the foundation for elucidating the molecular regulatory mechanisms of dairy cow mastitis.

Enterogenic Stenotrophomonas maltophilia migrates to the mammary gland to induce mastitis by activating the calcium-ROS-AMPK-mTOR-autophagy pathway

BACKGROUND

Mastitis is an inflammatory disease of the mammary gland that has serious economic impacts on the dairy industry and endangers food safety. Our previous study found that the body has a gut/rumen-mammary gland axis and that disturbance of the gut/rumen microbiota could result in 'gastroenterogenic mastitis'. However, the mechanism has not been fully clarified. Recently, we found that long-term feeding of a high-concentrate diet induced mastitis in dairy cows, and the abundance of Stenotrophomonas maltophilia (S. maltophilia) was significantly increased in both the rumen and milk microbiota. Accordingly, we hypothesized that 'gastroenterogenic mastitis' can be induced by the migration of endogenous gut bacteria to the mammary gland. Therefore, this study investigated the mechanism by which enterogenic S. maltophilia induces mastitis.

RESULTS

First, S. maltophilia was labelled with superfolder GFP and administered to mice via gavage. The results showed that treatment with S. maltophilia promoted the occurrence of mastitis and increased the permeability of the blood-milk barrier, leading to intestinal inflammation and intestinal leakage. Furthermore, tracking of ingested S. maltophilia revealed that S. maltophilia could migrate from the gut to the mammary gland and induce mastitis. Subsequently, mammary gland transcriptome analysis showed that the calcium and AMPK signalling pathways were significantly upregulated in mice treated with S. maltophilia. Then, using mouse mammary epithelial cells (MMECs), we verified that S. maltophilia induces mastitis through activation of the calcium-ROS-AMPK-mTOR-autophagy pathway.

CONCLUSIONS

In conclusion, the results showed that enterogenic S. maltophilia could migrate from the gut to the mammary gland via the gut-mammary axis and activate the calcium-ROS-AMPK-mTOR-autophagy pathway to induce mastitis. Targeting the gut-mammary gland axis may also be an effective method to treat mastitis.

N6-Methyladenosine-Modified circRNA in the Bovine Mammary Epithelial Cells Injured by Staphylococcus aureus and Escherichia coli

Mastitis is a common disease that hinders the development of dairy industry and animal husbandry. It leads to the abuse of antibiotics and the emergence of super drug-resistant bacteria, and poses a great threat to human food health and safety. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) are the most common pathogens of mastitis in dairy cows and usually cause subclinical or clinical mastitis. CircRNAs and N⁶-methyladenosine (m⁶A) play important roles in immunological diseases. However, the mechanisms by which m⁶A modifies circRNA in bovine mammary epithelial cells remain poorly understood. The aim of our study was to investigate m⁶A-modified circRNAs in bovine mammary epithelial cells (MAC-T cells) injured by S. aureus and E. coli. The profile of m⁶A-modified circRNA showed a total of 1,599 m⁶A peaks within 1,035 circRNAs in the control group, 35 peaks within 32 circRNAs in the S. aureus group, and 1,016 peaks within 728 circRNAs in the E. coli group. Compared with the control group, 67 peaks within 63 circRNAs were significantly different in the S. aureus group, and 192 peaks within 137 circRNAs were significantly different in the E. coli group. Furthermore, we found the source genes of these differentially m⁶A-modified circRNAs in the S. aureus and E. coli groups with similar functions according to GO and KEGG analyses, which were mainly associated with cell injury, such as inflammation, apoptosis, and autophagy. CircRNA–miRNA–mRNA interaction networks predicted the potential circRNA regulation mechanism in S. aureus- and E. coli-induced cell injury. We found that the mRNAs in the networks, such as BCL2, MIF, and TNFAIP8L2, greatly participated in the MAPK, WNT, and inflammation pathways. This is the first report on m⁶A-modified circRNA regulation of cells under S. aureus and E. coli treatment, and sheds new light on potential mechanisms and targets from the perspective of epigenetic modification in mastitis and other inflammatory diseases.

The Rumen Microbiota Contributes to the Development of Mastitis in Dairy Cows

Mastitis, a highly prevalent disease in dairy cows, is commonly caused by local infection of the mammary gland. Our previous studies have suggested that the gut microbiota plays an important role in the development of mastitis in mice. However, the effects of rumen microbiota on bovine mastitis and the related mechanisms remain unclear. In this study, we assessed the effects and mechanisms of rumen microbiota on bovine mastitis based on the subacute rumen acidosis (SARA) model induced by feeding Holstein Frisian cows a high-concentrate diet for 8 weeks. Then, the inflammatory responses in the mammary gland and the bacterial communities of rumen fluid, feces, and milk were analyzed. The results showed that SARA induced mastitis symptoms in the mammary gland; activated a systemic inflammatory response; and increased the permeability of the blood-milk barrier, gut barrier, and rumen barrier. Further research showed that lipopolysaccharides (LPS), derived from the gut of SARA cows, translocated into the blood and accumulated in the mammary glands. Furthermore, the abundance of Stenotrophomonas was increased in the rumen of SARA cows, and mastitis was induced by oral administration of Stenotrophomonas in lactating mice. In conclusion, our findings suggested that mastitis is induced by exogenous pathogenic microorganisms as well as by endogenous pathogenic factors. Specifically, the elevated abundance of Stenotrophomonas in the rumen and LPS translocation from the rumen to the mammary gland were important endogenous factors that induced mastitis. Our study provides a foundation for novel therapeutic strategies that target the rumen microbiota in cow mastitis. IMPORTANCE Mastitis is a common and frequently occurring disease of humans and animals, especially in dairy farming, which has caused huge economic losses and brought harmful substance residues, drug-resistant bacteria, and other public health risks. The traditional viewpoint indicates that mastitis is mainly caused by exogenous pathogenic bacteria infecting the mammary gland. Our study found that the occurrence of mastitis was induced by the endogenous pathway. Evidence has shown that rumen-derived LPS enters the mammary gland through blood circulation, damaging the blood-milk barrier and then inducing inflammation of the mammary gland in cows. In addition, a higher abundance of Stenotrophomonas in the rumen was closely associated with the development of mastitis. This study provides a basis for novel therapeutic strategies that exploit the rumen microbiota against mastitis in cows.

Qing-Dai for pediatric ulcerative colitis multicenter survey and systematic review

BACKGROUND

Pediatric ulcerative colitis (UC) is more challenging to treat than adult UC. Qing-Dai therapy is effective in adults but reports of its efficacy in children are unavailable. We conducted a questionnaire survey on Qing-Dai use among pediatric patients with UC in Japan to determine its efficacy and safety.

METHODS

Questionnaires were sent to 31 high-volume centers treating pediatric patients with inflammatory bowel disease. The number of patients using Qing-Dai, short-term and long-term effects, and adverse events were assessed. A systematic review of studies on the efficacy and safety of Qing-Dai usage for UC was also performed.

RESULTS

Overall, 29/31 facilities (93.5%) responded, Qing-Dai was used in 107 patients with UC, and 84/107 patients (78.5%) initiated treatment. Within 6 months, 81/101 (80.2%) patients had clinical remission, while 59/92 (64.1%) patients had no relapse and 29/92 (31.5%) experienced only one to two relapses yearly. Eighty-seven percent of the patients underwent regular follow ups for adverse events, among whom one patient was diagnosed with pulmonary arterial hypertension (PAH), five with enteritis, and one with headache. In the systematic review, the clinical remission rate was 50-80%, and PAH was observed in 14 of 1,158 patients (1.2%).

CONCLUSIONS

Qing-Dai is highly effective in treating pediatric UC. However, Qing-Dai should be administered with caution as it may cause adverse events such as PAH.

The Protective Effects of Lactobacillus plantarum KLDS 1.0344 on LPS-Induced Mastitis In Vitro and In Vivo

Cow mastitis, which significantly lowers milk quality, is mainly caused by pathogenic bacteria such as E. coli. Previous studies have suggested that lactic acid bacteria can have antagonistic effects on pathogenic bacteria that cause mastitis. In the current study, we evaluated the in vitro and in vivo alleviative effects of L. plantarum KLDS 1.0344 in mastitis treatment. In vitro antibacterial experiments were performed using bovine mammary epithelial cell (bMEC), followed by in vivo studies involving mastitis mouse models. In vitro results indicate that lactic acid was the primary substance inhibiting the E. coli pathogen. Meanwhile, treatment with L. plantarum KLDS 1.0344 can reduce cytokines' mRNA expression levels in the inflammatory response of bMEC induced by LPS. In vivo, the use of this strain reduced the secretion of inflammatory factors IL-6, IL-1β, and TNF-α, and decreased the activity of myeloperoxidase (MPO), and inhibited the secretion of p-p65 and p-IκBα. These results indicate that L. plantarum KLDS 1.0344 pretreatment can reduce the expression of inflammatory factors by inhibiting the activation of NF-κB signaling pathway, thus exerting prevent the occurrence of inflammation in vivo. Our findings show that L. plantarum KLDS 1.0344 has excellent properties as an alternative to antibiotics and can be developed into lactic acid bacteria preparation to prevent mastitis disease.

Genome-Wide Analysis of LncRNA in Bovine Mammary Epithelial Cell Injuries Induced by Escherichia Coli and Staphylococcus Aureus

Escherichia coli and Staphylococcus aureus are two common pathogenic microorganisms that cause mastitis in dairy cows. They can cause clinical mastitis and subclinical mastitis. In recent studies, lncRNAs have been found to play an important role in the immune responses triggered by microbial inducers. However, the actions of lncRNAs in bovine mastitis remain unclear. The purpose of this study was to investigate the effects of bovine mammary epithelial cell injuries induced by treatment with E. coli and S. aureus, and to explore the lncRNA profile on cell injuries. The lncRNA transcriptome analysis showed a total of 2597 lncRNAs. There were 2234 lncRNAs differentially expressed in the E. coli group and 2334 in the S. aureus group. Moreover, we found that the E. coli and S. aureus groups of maternal genes targeted signaling pathways with similar functions according to KEGG and GO analyses. Two lncRNA-miRNA-mRNA interaction networks were constructed in order to predict the potential molecular mechanisms of regulation in the cell injuries. We believe that this is the first report demonstrating the dysregulation of lncRNAs in cells upon E. coli and S. aureus infections, suggesting that they have the potential to become important diagnostic markers and to provide novel insights into controlling and preventing mastitis.

Rutin, A Natural Inhibitor of IGPD Protein, Partially Inhibits Biofilm Formation in Staphylococcus xylosus ATCC700404 in vitro and in vivo

Staphylococcus xylosus (S. xylosus) has become an emerging opportunistic pathogen due to its strong biofilm formation ability. Simultaneously, the biofilm of bacteria plays an important role in antibiotic resistance and chronic infection. Here, we confirmed that rutin can effectively inhibit biofilm formation in S. xylosus, of which the inhibition mechanism involves its ability to interact with imidazole glycerol phosphate dehydratase (IGPD), a key enzyme in the process of biofilm formation. We designed experiments to target IGPD and inhibited its activities against S. xylosus. Our results indicated that the activity of IGPD and the amount of histidine decreased significantly under the condition of 0.8 mg/ml rutin. Moreover, the expression of IGPD mRNA (hisB) and IGPD protein was significantly down-regulated. Meanwhile, the results from molecular dynamic simulation and Bio-layer interferometry (BLI) technique showed that rutin could bind to IGPD strongly. Additionally, in vivo studies demonstrated that rutin treatment reduced inflammation and protect mice from acute mastitis caused by S. xylosus. In summary, our findings provide new insights into the treatment of biofilm mediated persistent infections and chronic bacterial infections. It could be helpful to design next generation antibiotics to against resistant bacteria.

Morin Protects LPS-Induced Mastitis via Inhibiting NLRP3 Inflammasome and NF-κB Signaling Pathways

Mastitis is one of the most common diseases that both affects human and animals. Morin is derived from the member of Moraceae family, which has been used in the treatment of many inflammatory diseases. The purpose of this study was to test the protective effect of morin on LPS-induced mastitis and to clarify the possible mechanism. In vivo, the mastitis model was established by lipopolysaccharide (LPS), and morin was treated 1 h before stimulation of LPS. In vitro, peritoneal macrophages were used to test the regulation mechanisms of morin on mastitis. The inflammatory cytokines (TNF-α, IL-1β, and IL-6) was tested by ELISA. Myeloperoxidase (MPO) activity was measured by MPO kit. The expression of NLRP3 inflammasome and NF-κB signaling pathway proteins were detected by western blotting. The results showed that morin alleviated the pathological damage of mammary gland tissues, MPO activity, and the production of TNF-α, IL-1β, and IL-6 in mammary gland tissues. In vitro, morin significantly suppressed the production of inflammatory cytokines. In addition, it also inhibited the activation of NLRP3 inflammasome and NF-κB signaling pathway induced by LPS. In conclusion, the present study suggested that the protective effect of morin against LPS-induced mastitis may be due to its ability to inhibit NLRP3 inflammasome expression and NF-κB signaling pathway.

Hederacoside-C Inhibition of Staphylococcus aureus-Induced Mastitis via TLR2 & TLR4 and Their Downstream Signaling NF-κB and MAPKs Pathways In Vivo and In Vitro

Hederacoside-C (HDC) is a biological active ingredient, extracted from the leaves of Hedera helix. It has been reported to have anti-inflammatory properties. However, the effects of HDC on Staphylococcus aureus (S. aureus)-induced mastitis have not been reported yet. Here, we evaluated the anti-inflammatory effects of HDC on S. aureus-induced mastitis both in vivo on mammary gland tissues and in vitro on RAW 264.7 cells. The ascertained histopathological changes and MPO activity revealed that HDC defended mammary glands from tissue destruction and inflammatory cell infiltration induced by S. aureus. The results of ELISA, western blot, and qRT-PCR indicated that HDC significantly inhibited the expressions IL-6, IL-1β, and TNF-α and enhanced the IL-10 by downregulating and upregulating their relevant genes, respectively. Furthermore, HDC markedly suppressed the TLR2 and TLR4 expressions by attenuating the MAPKs (p38, ERK, JNK) and NF-κB (p65 and IκBα) pathways followed by decreasing the phosphorylation of p38, ERK, JNK, p65, and IκBα. The above parameters enhanced the mammary gland defense and reduced inflammation. These findings suggested that HDC may have the potential to be an effective anti-inflammatory drug for the S. aureus-induced mice mastitis and in RAW 264.7 cells.

From natural dye to herbal medicine: a systematic review of chemical constituents, pharmacological effects and clinical applications of indigo naturalis

Background

Indigo naturalis is a blue dye in ancient, as well as an extensive used traditional Chinese medicine. It has a wide spectrum of pharmacological properties and can be used to treat numerous ailments such as leukemia, psoriasis, and ulcerative colitis. This article aims to expand our understanding of indigo naturalis in terms of its chemical constituents, pharmacological action and clinical applications.

Methods

We searched PubMed, web of science, CNKI, Google academic, Elsevier and other databases with the key words of “Indigo naturalis”, and reviewed and sorted out the modern research of indigo naturalis based on our research results.

Results

We outlined the traditional manufacturing process, chemical composition and quality control of indigo naturalis, systematically reviewed traditional applictions, pharmacological activities and mechanism of indigo naturalis, and summarized its clinical trials about treatment of psoriasis, leukemia and ulcerative colitis.

Conclusions

Indigo naturalis has a variety of pharmacological activities, such as anti-inflammatory, antioxidant, antibacterial, antiviral, immunomodulatory and so on. It has very good clinical effect on psoriasis, leukemia and ulcerative colitis. However, it should be noted that long-term use of indigo naturalis may produce some reversible adverse reactions. In summarize, indigo naturalis is an extremely important drug with great value and potential.

Gambogic acid alleviates inflammation and apoptosis and protects the blood-milk barrier in mastitis induced by LPS

Mastitis is one of the most common diseases among dairy cows. There is still much debate worldwide as to whether antibiotic therapy should be given to dairy cows, or if natural products should be taken as a substitute for antibacterial therapy. As the antibiotic treatment leads to the bacterial resistance and drug residue in milk, introducing natural products for mastitis is becoming a trend. This study investigates the mechanisms of the protective effects of the natural product gambogic acid (GA) in lipopolysaccharide (LPS)-induced mastitis. For in vitro treatments, it was found that GA reduced IL-6, TNF-α, and IL-1β levels by inhibiting the phosphorylation of proteins in the nuclear factor κB (NF-κB) and the mitogen-activated protein kinase (MAPK) pathway. GA also maintained a stable membrane mitochondrial potential and inhibited the overproduction of reactive oxygen species, which protected the cells from apoptosis. On the other hand, in vivo treatments with GA were found to reduce pathological symptoms markedly, and protected the blood-milk barrier from damage induced by LPS. The results demonstrate that GA plays a vital role in suppressing inflammation, alleviating the apoptosis effect, and protecting the blood-milk barrier in mastitis induced by LPS. Thus, these results suggest that the natural product GA plays a potential role in mastitis treatment.

In vitro activity and In vivo efficacy of Isoliquiritigenin against Staphylococcus xylosus ATCC 700404 by IGPD target

Staphylococcus xylosus (S. xylosus) is a type of coagulase-negative Staphylococcus, which was previously considered as non-pathogenic. However, recent studies have linked it with cases of mastitis in cows. Isoliquiritigenin (ISL) is a bioactive compound with pharmacological functions including antibacterial activity. In this study, we evaluated the effect of ISL on S. xylosus in vitro and in vivo. The MIC of ISL against S. xylosus was 80 μg/mL. It was observed that sub-MICs of ISL (1/2MIC, 1/4MIC, 1/8MIC) significantly inhibited the formation of S. xylosus biofilm in vitro. Previous studies have observed that inhibiting imidazole glycerol phosphate dehydratase (IGPD) concomitantly inhibited biofilm formation in S. xylosus. So, we designed experiments to target the formation of IGPD or inhibits its activities in S. xylosus ATCC 700404. The results indicated that the activity of IGPD and its histidine content decreased significantly under 1/2 MIC (40 μg/mL) ISL, and the expression of IGPD gene (hisB) and IGPD protein was significantly down-regulated. Furthermore, Bio-layer interferometry experiments showed that ISL directly interacted with IGPD protein (with strong affinity; KD = 234 μM). In addition, molecular docking was used to predict the binding mode of ISL and IGPD. In vivo tests revealed that, ISL significantly reduced TNF-α and IL-6 levels, mitigated the destruction of the mammary glands and reversed the production of inflammatory cells in mice. The results of the study suggest that, ISL may inhibit S. xylosus growth by acting on IGPD, which can be used as a target protein to treat infections caused by S. xylosus.

Sodium butyrate alleviates lipopolysaccharide-induced endometritis in mice through inhibiting inflammatory response

Endometritis is commonly occurred in dairy cows after calving and results in a great deal of property damage. Although numerous studies have been performed to find the therapeutic agents for endometritis, the incidence of this disease remains high. Short-chain fatty acids (SCFAs), the major metabolic products of anaerobic bacteria fermentation in the gut, have been reported to exhibit anti-inflammatory properties. Therefore, the purpose of this study was to investigate the protective effects and mechanisms of sodium butyrate (SB) on lipopolysaccharide (LPS)-induced endometritis in mice. The mice were administered by intraperitoneal injection of SB at 1 h before LPS injection. 24 h later, the uterus tissues were collected. Hematoxylin and eosin (H & E) stained sections of uterus were used to determine the degree of the damage. Uterine myeloperoxidase (MPO) activity was used to analyze neutrophil granulocytes concentration. The levels of pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured by ELISA. The activation of the NF-κB signaling pathway proteins were detected by Western blot analysis. The results showed that SB significantly attenuated the pathological injury of the uterus tissues. SB also suppressed LPS-induced MPO activity and the production of inflammatory cytokines TNF-α and IL-1β. Furthermore, Western blot analysis showed that SB inhibited the activation of NF-κB signaling pathway. In addition, SB could inhibit histone deacetylases. In summary, SB protects against LPS-induced endometritis through HDAC inhibition.

Neutralization of Interleukin-17A Attenuates Lipopolysaccharide-Induced Mastitis by Inhibiting Neutrophil Infiltration and the Inflammatory Response

Mastitis has been recognized as a common and major disease of cows with a strong impact on dairy farming. Interleukin-17A (IL-17A) has been shown to mediate crucial crosstalk between the immune system and various epithelial tissues, initiating a series of defensive mechanisms against bacterial and fungal infections. This crosstalk is especially involved in neutrophil infiltration. To evaluate the role of IL-17A in immune defense in the mammary gland in mice, we tested the effects of depleting IL-17A on changes in pathology, neutrophil infiltration, and pro-inflammatory cytokine levels in the mammary gland stimulated by lipopolysaccharide (LPS). Further, the effects of IL-17A on the activation of the nuclear factor-κB (NF-κB) signaling pathway during mastitis induced by LPS were also studied. The results showed that the production of IL-17A was significantly elevated during mastitis induced by LPS. IL-17A blockade via an intraperitoneal antibody injection protected against LPS-induced mastitis, as indicated by decreased neutrophil infiltration, myeloperoxidase activity, pro-inflammatory cytokines levels, and NF-κB signaling pathway molecule phosphorylation in response to LPS. In conclusion, an elevated IL-17 level plays a crucial role during mastitis, and anti-IL-17A antibody blockade protects against LPS-induced mammary gland inflammation induced through the NF-κB signaling pathway, which provides a new potential treatment target for mastitis.

Indirubin modulates CD4+ T-cell homeostasis via PD1/PTEN/AKT signalling pathway in immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disease characterized by an immune mediated decrease in platelet number. Disturbance of CD4⁺ T-cell homeostasis with simultaneous decrease of CD4⁺ CD25⁺ Foxp3⁺ regulatory T cells (Tregs) as well as unrestricted proliferation and activation of peripheral CD4⁺ effector T cells underpin the pathophysiology of ITP. Indirubin is an active ingredient of a traditional Chinese herb called Indigofera tinctoria L. which is clinically used for the treatment of ITP patients. Whether indirubin targets the Tregs/effector T cell-axis to restore platelet number is unknown. In our in vitro studies, Indirubin could significantly enhance the number and function of Tregs and meanwhile dampen the activation of effector T cells in a dose-dependent manner. Indirubin was observed to restore the expression of programmed cell-death 1 (PD1) and phosphatase and tensin homolog (PTEN) on the CD4⁺ T cells of ITP patients, leading to the subsequent attenuation of the AKT/mTOR pathway. Furthermore, these observations were recapitulated in an active murine model of ITP with a prominent platelet response. Thus, our results identified a potentially novel mechanism of the therapeutic action of indirubin in the treatment of ITP through regulating the homeostasis of CD4⁺ T cells in a PD1/PTEN/AKT signalling pathway.

Melatonin inhibits endoplasmic reticulum stress-associated TXNIP/NLRP3 inflammasome activation in lipopolysaccharide-induced endometritis in mice

Endometritis, an inflammatory response of the uterus tissue, is characterized by the production of inflammatory cytokines and migration of neutrophil (PMN) into the uterus tissue. Melatonin has been demonstrated to have anti-inflammatory and antioxidant effects. The purpose of this study was to investigate the protective effects of melatonin on lipopolysaccharide (LPS)-induced endometritis in mice. An endometritis model was induced by LPS and melatonin was given 1 h before LPS treatment. The results showed that melatonin inhibited LPS-induced pathologic changes, Myeloperoxidase (MPO) activity, and levels of interleukin-1 beta (IL-1β). Melatonin also inhibited LPS-induced thioredoxin-interacting protein (TXNIP)/NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and nuclear factor kappa B (NF-κB) activation, reactive oxygen species (ROS) production, and endoplasmic reticulum (ER) stress. Furthermore, melatonin was found to increase AMPK activity. In conclusion, our results demonstrated that melatonin inhibited ER stress-associated TXNIP/NLRP3 inflammasome activation with a regulation of adenosine monophosphate activated protein kinase (AMPK) in LPS-induced endometritis. Melatonin may serve as a promising nutritional supplement for the treatment of endometritis.

Rutin protects against lipopolysaccharide-induced mastitis by inhibiting the activation of the NF-κB signaling pathway and attenuating endoplasmic reticulum stress

Rutin, found widely in traditional Chinese medicine materials, is used to treat eye swelling and pain, hypertension, and hyperlipidemia. In the present study, a mouse mastitis model induced by lipopolysaccharide (LPS) was established to explore rutin's inhibitory mechanism on mastitis via nuclear factor kappa B (NF-κB) inflammatory signaling and the relationship between NF-κB signaling and endoplasmic reticulum (ER) stress. Mice were divided into six groups: Control group, LPS model group, LPS + rutin (25, 50, and 100 mg/kg) and LPS + dexamethasone (DEX) group. DEX, rutin, and PBS (control and LPS groups) were administered 1 h before and 12 h after perfusion of LPS. After LPS stimulation for 24 h, to evaluate rutin's therapeutic effect on mastitis, the mammary tissues of each group were collected to detect histopathological injury, tumor necrosis factor alpha (TNF-α), interleukin (IL)-1β, and IL-6 mRNA and protein levels; and glucose-regulated protein, 78 kDa (GRP78) protein levels. The protein and mRNA levels of TNF-α, IL-1β, and IL-6 in the LPS + rutin group were significantly lower than those in the LPS model group. Similarly, p50/p105, phosphorylated (p)-p65/p65 and p-inhibitor of nuclear factor kappa b kinase subunit beta (p-IKKβ)/IKKβ ratios in the LPS + rutin group (50 mg/kg) and LPS + rutin group (100 mg/kg) decreased significantly. GRP78 protein expression was significantly higher in LPS + rutin group (100 mg/kg). The structure of mammary tissue became gradually more intact and vacuolization of acini decreased as the rutin concentration increased. The nuclear quantity of p65 in the LPS + rutin group decreased significantly in a rutin dose-dependent manner. Rutin had an anti-inflammatory effect in the LPS-induced mouse mastitis model, manifested by inhibition of NF-κB pathway activation and attenuation of ER stress.

The combination of indirubin and isatin attenuates dextran sodium sulfate induced ulcerative colitis in mice

Indirubin and isatin have been used in the treatment of inflammatory diseases due to their anti-inflammatory properties. This study aimed to evaluate the combined effect of indirubin and isatin on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). UC was induced by the administration of 3% (w/v) DSS solution, and then the model mice were administered indirubin (10 mg/kg body mass) and (or) isatin (10 mg/kg body mass) by gavage once daily for 7 days. The results showed that indirubin and isatin, individually or combined, significantly inhibited weight loss, lowered disease activity index (DAI), ameliorated pathological changes, decreased the levels of pro-inflammatory mediators and myeloperoxidase (MPO) activity, increased the expression of anti-inflammatory cytokines and Foxp3, suppressed CD4⁺ T cell infiltration, and inhibited oxidative stress and epithelial cell apoptosis. Additionally, indirubin and isatin, both individually and combined, can also inhibit activation of the NF-κB and MAPK pathways induced by DSS. The protective effect of combination therapy against UC was superior to that of single-agent treatment. These results suggest that indirubin combined with isatin attenuates DSS-induced UC, and changes to the NF-κB and MAPK signaling pathways may mediate the protective effects of indirubin and isatin in UC.

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.