General practitioners' management of mastitis in breastfeeding women: a mixed method study in Australia.

BACKGROUND: Mastitis is a common reason new mothers visit their general practitioner (GP). In Australia, the Therapeutic Guidelines: Antibiotic provides practical advice to GPs managing a range of infections, including mastitis. It is not known if Australian GPs prescribe antibiotics and order investigations as recommended for the management of mastitis. METHODS: A convergent mixed methods design integrated quantitative analysis of a general practice dataset with analysis of interviews with GPs. Using the large-scale primary care dataset, MedicineInsight, (2021-2022), antibiotics prescribed and investigations ordered for mastitis encounters were extracted. Mastitis encounters were identified by searching 'Encounter reason', 'Test reason' and 'Prescription reason' free text field for the term 'mastitis'; 'granulomatous mastitis' was excluded. Clinical encounters for mastitis occurring within 14 days of a previous mastitis encounter were defined as belonging to the same treatment episode. Semi-structured interviews were conducted with 14 Australian GPs using Zoom or telephone in 2021-2022, and analysed thematically. The Pillar Integration Process was used to develop a joint display table; qualitative codes and themes were matched with the quantitative items to illustrate similarities/contrasts in findings. RESULTS: During an encounter for mastitis, 3122 (91.7%) women received a prescription for an oral antibiotic; most commonly di/flucloxacillin ([59.4%]) or cefalexin (937 [27.5%]). Investigations recorded ultrasound in 303 (8.9%), blood tests (full blood examination [FBE]: 170 [5.0%]; C-reactive protein [CRP]: 71 [2.1%]; erythrocyte sedimentation rate [ESR]: 34 [1.0%]) and breast milk or nipple swab cultures in approximately 1% of encounters. Analysis using pillar integration showed consistency between quantitative and qualitative data regarding mastitis management. The following themes were identified: - GPs support continued breastfeeding. - Antibiotics are central to GPs' management. - Antibiotics are mostly prescribed according to Therapeutic Guidelines. - Analgesia is a gap in the Therapeutic Guidelines. - Low use of breast milk culture. CONCLUSIONS: Prescribing antibiotics for mastitis remains central to Australian GPs' management of mastitis. Interview data clarified that GPs were aware that antibiotics might not be needed in all cases of mastitis and that delayed prescribing was not uncommon. Overall, GPs followed principles of antibiotic stewardship, however there is a need to train GPs about when to consider ordering investigations.

Alternative therapeutic approach of ovine subclinical mastitis using the ethanolic roots extract of Capparis spinosa.

Background: Over the past decades, Capparis spinosa has been considered a traditional therapy for relieving different illnesses. Mastitis causes a decrease in milk production and is usually treated with injectable and intra-mammary antibiotics. Aim: Investigating the therapeutic effects of C. spinosa root extract on subclinically mastitic ewes. Methods: Totally, 164 lactating ewes were selected randomly from the flocks that existed in some areas belonging to Al-Najaf City (Najaf, Iraq) from September to December (2022). Each study animal was subjected to direct sampling of milk before and once each week for 6 weeks (42 days) post treatment to be tested directly by the California mastitis test (CMT). Results: Concerning phytochemical testing of ethanolic root extract, the findings revealed a significant increase in the concentration of alkaloids, flavonoids, polyphenols, and tannins when compared to other components such as coumarins, saponin, glycosides, amino acids, and steroids. In this study, there were 44.51% infected ewes with subclinical mastitis, involving 25.61%, 13.41%, and 5.49% for scores 1, 2, and 3, respectively. In comparison with pre-treatment week, insignificant alteration was seen in the values of all scores in therapeutic week 1. However, significant differences were initiated in values of score 0 in week 2; score 0 and score 2 in week 3; score 0, score 1, and score 2 in week 4; and values of all scores in weeks 5 and 6. Conclusion: This represents the first Iraqi study aimed at the treatment of subclinical mastitis in sheep using the root extract of C. spinosa. Phytochemical testing of ethanolic extract revealed the presence of variable amounts of chemical compounds that reflect their effects on treated animals by decreasing the number of infected ewes with the disease. Moreover, studies are greatly important to estimate the therapeutic effects of other parts of C. spinosa such as leaves and seeds, on the disease and other animal diseases.

Effect and mechanism of Prunella vulgaris L. extract on alleviating lipopolysaccharide-induced acute mastitis in protecting the blood-milk barrier and reducing inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: According to ancient literature, Prunella vulgaris L. (P vulgaris) alleviates mastitis and has been used in China for many years; however, there are no relevant reports that confirm this or the mechanism of its efficacy. AIM OF THE STUDY: To explore the anti-acute mastitis effect and potential mechanism of P vulgaris extract. MATERIALS AND METHODS: First, the active ingredients and targets of P vulgaris against mastitis were predicted using network pharmacology. Next, the relevant active ingredients were enriched using macroporous resins and verified using UV and UPLC-Q-TOF-MS/MS. Lastly, a mouse model of acute mastitis was established by injecting lipopolysaccharides into the mammary gland and administering P vulgaris extract by oral gavage. The pathological changes in mammary tissue were observed by HE staining. Serum and tissue inflammatory factors were measured by ELISA method. MPO activity in mammary tissue was measured using colorimetry and MPO expression was detected by immunohistochemistry. The expression of tight junction proteins (ZO-1, claudin-3, and occludin) in mammary tissue was detected by immunofluorescence and Western blot. iNOS and COX-2 in mammary tissue were detected by Western blot. MAPK pathway and NF-κB pathway related proteins were also detected by Western blot. RESULTS: Network pharmacology predicted that phenolic acids and flavonoids in P vulgaris had anti-mastitis effects. The contents of total flavonoids and total phenolic acids in P vulgaris extract were 64.5% and 29.4%, respectively. UPLC-Q-TOF-MS/MS confirmed that P vulgaris extract contained phenolic acids and flavonoids. The results of animal experiments showed that P vulgaris extract reduced lipopolysaccharide-induced inflammatory edema, inflammatory cell infiltration, and interstitial congestion of mammary tissue. It also reduced the levels of serum and tissue inflammatory factors TNF-α, IL-6, and IL-1ß, and inhibited the activation of MPO. Furthermore, it downregulated the expression of MAPK and NF-κB pathway-related proteins. The expressions of ZO-1, occludin, and claudin-3 in mammary gland tissues were upregulated. CONCLUSIONS: P vulgaris extract can maintain the integrity of mammary connective tissue and reduce its inflammatory response to prevent acute mastitis. Its mechanism probably involves regulating NF-κB and MAPK pathways.

MCC950 attenuates plasma cell mastitis in an MDSC-dependent manner.

Plasma cell mastitis (PCM) is a sterile inflammatory condition primarily characterized by periductal inflammation and ductal ectasia. Currently, there is a lack of non-invasive or minimally invasive treatment option other than surgical intervention. The NLRP3 inflammasome has been implicated in the pathogenesis and progression of various inflammatory diseases, however, its involvement in PCM has not yet been reported. In this study, we initially observed the pronounced upregulation of NLRP3 in both human and mouse PCM tissue and elucidated the mechanism underlying the attenuation of PCM through inhibition of NLRP3. We established the PCM murine model and collected samples on day 14, when inflammation reached its peak, for subsequent research purposes. MCC950, an NLRP3 inhibitor, was utilized to effectively ameliorate PCM by significantly reducing plasma cell infiltration in mammary tissue, as well as attenuate the expression of pro-inflammatory cytokines including IL-1ß, TNF-α, IL-2, and IL-6. Mechanistically, we observed that MCC950 augmented the function of myeloid-derived suppressor cells (MDSCs), which in turn inhibited the infiltration of plasma cells. Furthermore, it was noted that depleting MDSCs greatly compromised the therapeutic efficacy of MCC950. Collectively, our findings suggest that the administration of MCC950 has the potential to impede the progression of PCM by augmenting MDSCs both numerically and functionally, ultimately treating PCM effectively. This study provides valuable insights into the utilization of pharmacological agents for PCM treatment.

Effects of topical application of resveratrol on tight junction barrier and antimicrobial compound production in lactating goat mammary glands.

In mammary glands, the formation of less-permeable tight junctions (TJs) and the production of antimicrobial compounds like lactoferrin and defensins are important for preventing mastitis. Resveratrol, a polyphenol contained in red grapes, is known to protect mammary epithelial cells (MECs) from oxidative stress; however, oral administration of resveratrol causes a decrease in certain biological processes through conjugation and metabolic conversion. In this study, we determined the beneficial effects of resveratrol on TJs and antimicrobial compounds in cultured goat MECs by adding it to the medium, and in lactating goat mammary glands by topical application for percutaneous absorption. TJ barrier function was evaluated by transepithelial resistance and expression or localization pattern of claudins for culture model in vitro and by somatic cell count, Na+, albumin, and IgG in milk for topical application in vivo. Concentrations of antimicrobial compounds and cytokines were measured using ELISA. Activation of STAT3 was evaluated by Western blotting. Resveratrol strengthened TJ barrier function by upregulating claudin-3 in cultured MECs and topical application to udders reduced somatic cell count, Na+, albumin, and IgG in milk. Resveratrol increased ß-defensin and S100A7 levels in cultured MECs and milk. In addition, resveratrol down-regulated cytokine production and STAT3 pathway. These findings suggest that the topical application of resveratrol to udders may be effective in preventing mastitis.

A novel glycine-rich peptide from Zophobas atratus, coleoptericin B, targets bacterial membrane and protects against Klebsiella pneumoniae-induced mastitis in mice.

OBJECTIVES: The growing occurrence of bacterial resistance has spawned the development of novel antimicrobial agents. Antimicrobial peptides, a class of small molecules with antimicrobial activity, have been regarded as the ideal alternatives to antibiotics. METHODS: In this study, we amplified a new type of Zophobas atratus coleoptericin (denoted coleoptericin B) through rapid amplification of cDNA ends (RACE) PCR and expressed recombinant Z. atratus coleoptericin B (rZA-col B) by prokaryotic expression. Subsequently, we evaluated the antimicrobial effect and biocompatibility of rZA-col B in vivo, investigated its antimicrobial mechanism, and assessed its therapeutic effect in a murine model of mastitis caused by MDR Klebsiella pneumoniae. RESULTS: The in vivo studies demonstrated that rZA-col B possesses broad-spectrum antimicrobial activity against both Gram-positive and Gram-negative bacteria. It exhibited less than 1.5% haemolysis and 10% cytotoxicity, even at a concentration of 128 µM. Additionally, rZA-col B had a minimal risk of inducing drug resistance. Furthermore, rZA-col B could disrupt the integrity of bacterial membranes, induce membrane permeabilization and ultimately lead to bacterial death. Importantly, rZA-col B also alleviated mastitis caused by MDR K. pneumoniae in a murine model by enhancing bacterial clearance, reducing neutrophil infiltration, decreasing TNF-α and IL-1ß expression, and protecting the mammary barrier. CONCLUSIONS: rZA-col B may be a promising antibacterial agent to combat MDR bacterial infection.

Randomised Controlled Trial on Prophylaxis of Mastitis-Metritis-Agalactia Syndrome in Swine using Caulophyllum Logoplex and Lachesis Logoplex.

BACKGROUND: Mastitis-metritis-agalactia (MMA) syndrome occurs in the first days post-partum and causes piglet losses mainly due to malnutrition. One possibility for prophylaxis of MMA is via homeopathy. In this veterinary study, the effectiveness of a prophylactic administration of homeopathic remedies for the prevention of the occurrence of MMA in swine was evaluated. METHODS: In a randomised and blinded study, 60 sows were examined. Sows were randomly distributed in two groups: the experimental group (CL/LL) received a prophylactic administration of the complex homeopathic remedies Caulophyllum Logoplex and Lachesis Logoplex, and the placebo group was administered a sodium chloride (NaCl) solution in the same injection scheme as the experimental group. Clinical signs of MMA, behavioural changes, as well as production parameters, were recorded beginning with the day of farrowing until 5 days post-partum. RESULTS: The treatment group showed no significant effect on the occurrence of MMA in sows (CL/LL: 56.67% MMA positive sows; NaCl: 53.53% MMA positive sows). Treatment group had also no significant effect on health parameters (vaginal discharge, raised rectal temperature, shortage of milk) or behavioural parameters (impaired feeding behaviour and impaired general condition). For the production parameter average weight gain, statistically significant effects in the treatment group were detected. CONCLUSIONS: Prophylaxis with the homeopathic remedies Caulophyllum Logoplex and Lachesis Logoplex showed neither an improvement in MMA prevention nor an improvement in health parameters or behavioural traits in the present herd of sows.

Association of the Japanese herbal kampo medicine kakkonto with antibiotic use and surgical drainage for noninfectious mastitis: A nationwide database study.

AIM: Kakkonto, a Japanese herbal kampo medicine, is empirically prescribed to improve milk stasis and ameliorate breast inflammation in patients with noninfectious mastitis. We investigated whether early use of kakkonto is associated with a reduction in antibiotic use and surgical drainage in patients with noninfectious mastitis. METHODS: We identified 34 074 patients with an initial diagnosis of noninfectious mastitis within 1 year of childbirth between April 2012 and December 2022 using the nationwide administrative JMDC Claims Database. Patients were divided into the kakkonto (n = 9593) and control (n = 9648) groups if they received and did not receive kakkonto on the day of the initial diagnosis of noninfectious mastitis, respectively. Antibiotic administration and surgical drainage within 30 days after the initial diagnosis of noninfectious mastitis in the two groups were compared using propensity score-stabilized inverse probability of treatment weighting analysis. RESULTS: The frequency of antibiotic administration within 30 days after the initial diagnosis of noninfectious mastitis was significantly lower in the kakkonto group than in the control group (10% vs. 12%; odds ratio, 0.88 [95% confidence interval, 0.80-0.96]). The frequency of antibiotic administration during 1-3 and 4-7 days after the initial diagnosis were also significantly lower in the kakkonto group than in the control group. The frequency of surgical drainage did not differ significantly between the two groups. CONCLUSIONS: Kakkonto was associated with reduced administration of antibiotics for noninfectious mastitis, making it a potential treatment option for relieving breast inflammation and promoting antimicrobial stewardship.

The inhibition effect of caffeic acid on NOX/ROS-dependent macrophages M1-like polarization contributes to relieve the LPS-induced mice mastitis.

The mammary gland is an adipose tissue containing not only adipocytes but also epithelial, endothelial, and immune cells. Epithelial cells and macrophages, as the integral components of the immune system, are on the front line of defense against infection. Our preliminary work proved that caffeic acid (CA) can effectively inhibit the inflammatory cascade of bovine mammary epithelial cells (BMEC) induced by lipopolysaccharide (LPS) and maintain cellular integrity and viability. Here, we investigated the therapeutic effect of CA on LPS-induced mice mastitis and explored its regulatory mechanism on macrophage inflammatory response induced by LPS in vitro. Firstly, the mice mastitis model was established by intramammary injection with 10 µg LPS, after which different CA doses (5, 10, 15 mg/kg) were administered. Then, the pathological section, myeloperoxidase (MPO) activity, proinflammatory factors and chemokines releasement, and redox state of mammary tissues were assessed, confirming CA's effectiveness on mice mastitis. In vitro, we validated the therapeutic relevance of CA in relieving LPS-induced RAW264.7 inflammatory and oxidative stress responses. Moreover, we further provided evidence that CA significantly reduced LPS-induced reactive oxygen species (ROS) generation via NADPH oxidase (NOX), which improved the imbalance relationship between nuclear factor kappa-B (NF-κB) and NF-E2 p45-related factor 2 (Nrf2) and led to a marked weakening of M1 polarization. The NOX-ROS signal inhibited by CA weakened the oxidative burst and neutrophil chemotaxis of macrophages, thus alleviating the immune cascade in mammary gland tissue and reducing the LPS-induced inflammatory damage. Collectively, CA would be a potential candidate or antibacterial synergist for curbing mastitis.

Wogonin attenuates inflammation and oxidative stress in lipopolysaccharide-induced mastitis by inhibiting Akt/NF-κB pathway and activating the Nrf2/HO-1 signaling.

Mastitis is a disease involved in inflammation of breast which affects human and animals. Wogonin is one bioactive compound from many Chinese herbal medicines, which have multiple properties, including anti-inflammatory activity. However, the roles of wogonin in mastitis progression are largely undefined. Mastitis models were established using LPS-treated mice and mammary epithelial cells (MECs). Infiltration of inflammatory cells was analyzed by hematoxylin-eosin staining and myeloperoxidase (MPO) activity. Inflammatory cytokine (TNF-α and IL-1ß) levels were detected via ELISA. The phosphorylation and total of Akt and NF-κB levels and content of Nrf2 and HO-1 were measured via western blot. Cell viability was examined by CCK-8 assay. Oxidative stress was assessed by ROS generation and levels of MDA, GSH, and SOD. Wogonin attenuated LPS-induced infiltration of inflammatory cells, increase of MPO activity and levels of TNF-α and IL-1ß, and activation of the Akt/NF-κB pathway in murine mammary gland tissues, and promoted activation of Nrf2/HO-1 signaling. Wogonin did not affect MEC viability, but mitigated LPS-induced inflammation in MECs by reducing TNF-α and IL-1ß levels. Wogonin relieved LPS-induced oxidative stress in MECs through decreasing ROS generation and MDA level and increasing GSH and SOD levels. Wogonin repressed LPS-induced activation of the Akt/NF-κB pathway in MECs and increased Nrf2/HO-1 signaling activation. Activated Akt/NF-κB signaling or Nrf2/HO-1 signaling inactivation reversed the suppressive effects of wogonin on LPS-induced inflammation and oxidative stress in MECs. Wogonin mitigates LPS-induced inflammation and oxidative stress of MECs via suppressing activation of the Akt/NF-κB signaling and activating Nrf2/HO-1 pathway, indicating the therapeutic potential of wogonin in mastitis.

[Breast tuberculosis. Report of two cases]. / Tuberculosis mamaria. Reporte de dos casos.

Two cases of mammary tuberculosis (TB) are presented, one of them with additional pleural and lymph node involvement. Both were HIV-negative, with no history of previous TB, with long-standing breast lesions. Both presented a successful outcome with antituberculosis treatment. Breast TB is a very rare pathology that is difficult to diagnose. The cases are presented to consider their differential diagnosis in patients with chronic mastitis and/or nodular or ulcerated lesions of the breast. Multidisciplinary management is recommended.

Se presentan los casos de dos pacientes con tuberculosis (TB) mamaria, una de ellas también con compromiso pleural y ganglionar. Ambas HIV negativas, sin antecedentes de TB previa, con lesiones mamarias de largo tiempo de evolución. Las dos presentaron buena evolución con tratamiento antifímico. La TB mamaria es una afección muy poco frecuente de difícil diagnóstico. Se presentan los casos con el fin de plantear su diagnóstico diferencial en pacientes con mastitis crónicas y/o lesiones nodulares o ulceradas de la mama. Se recomienda el manejo multidisciplinario.

Retinoic acid ameliorates low-grade endotoxemia-induced mastitis by limiting inflammatory responses in mice.

Mastitis is a serious disease for humans and animals, which causes huge economic losses in the dairy industry and is hard to prevent due to the complex and unclear pathogenesis. Subacute ruminal acidosis (SARA) has contributed to the development of mastitis by inducing ruminal dysbiosis and subsequent low-grade endotoxemia (LGE), however, how ruminal metabolic changes regulate this progress is still unclear. Our previous study revealed that cows with SARA had increased ruminal retinoic acid (RA) levels, a metabolic intermediate of vitamin A that plays an essential role in mucosal immune responses. Hence, the aim of this study was to investigate the protective effect of RA on LGE-induced mastitis and the underlying mechanisms in mice. The results showed that RA alleviated LGE-induced mastitis, as evidenced by RA significantly reduced the increase in mammary proinflammatory cytokines and improved blood-milk barrier injury caused by LGE. In addition, RA increased the expression of tight junction proteins, including ZO-1, occludin and claudin-3. Furthermore, we found that RA limited the mammary inflammatory responses by inhibiting the activation of NF-κB and NLRP3 signaling pathways. These findings suggest that RA effectively alleviates LGE-induced mastitis and implies a potential strategy for the treatment and prevention of mastitis and other diseases.

Antibacterial activity of medicinal plants on the management of mastitis in dairy cows: A systematic review.

BACKGROUND: Mastitis is a disease of economic importance in dairy production systems. The common management regime for mastitis is the use of synthetic antibiotics, giving a new problem of antibiotic resistance. There is, therefore, a need to prospect for alternatives to conventional antibiotics from herbal plants. OBJECTIVES: This systematic review evaluates the use of plants as alternatives for the control of mastitis in dairy cattle, focussing on the effectiveness of studied plants and plant-based products and possible implications on the use of these products in livestock health. METHODOLOGY: The PRISMA model was implemented with searches done in five electronic databases: Scopus, ScienceDirect, PubMed, Ovid and Research4Life. Data were extracted from 45 studies with 112 plant species from plant species belonging to 42 different families. The specific keywords were 'mastitis', 'dairy cows' and 'medicinal plants'. RESULTS: The most cited plant species included Allium sativum L., Azadirachta indica and Eucalyptus globulus Labill with the latter further exploring its components. Microbial species causing mastitis mainly were Staphylococcus aureus and Escherichia coli. The extraction methods used included maceration approach using ethanol, methanol and water as solvents for phytochemicals and chromatographic techniques for essential oils. A few studies explored the mode of action, and toxicities of the herbal extracts as well as evaluating their efficacy in clinical trials using animal models. CONCLUSION: Plants with defined levels of phytochemicals were essential sources of antibacterials. Standardisation of analytical methods is required.

Clinical efficacy of Gualou Xiaoyong Decoction and painless lactation manipulation in treating lactation acute mastitis and breast abscess: An observational study.

Information on the effects of Chinese medicine in the treatment of lactational acute mastitis and breast abscess is limited; thus, we conducted an observational study to analyze the clinical efficacy of Gualou Xiaoyong Decoction combined with painless lactation manipulation in the treatment of lactational acute mastitis and breast abscess. A total of 41 patients with lactational acute mastitis and breast abscess who were treated with Gualou Xiaoyong Decoction and painless lactation manipulation from October 2021 to October 2022 were included in this study. The age, fetal times(primiparous/multiparous), delivery mode (cesarean section/vaginal delivery), onset time, breast lump diameter, skin rash diameter, body temperature, visual analogue score, blood routine, C-reactive protein, procalcitonin, bacterial culture in milk, B ultrasound and other data of these patients were statistically analyzed. After treatment, the breast lump diameter of these patients decreased significantly, the skin rash diameter was reduced or disappeared, the body temperature decreased or returned to a normal range, and the visual analogue score also decreased. Besides, these patients had a decreased total number of white blood cells and a reduced percentage of neutrophils, C-reactive protein, and procalcitonin after treatment. In addition, bacteria in the milk of most patients disappeared, and there was no abnormality in B ultrasonic imaging. Except for 2 patients with breast abscess who stopped breastfeeding on the affected side for 1 day and 3 days respectively, all other patients continued to provide breast milk for their infants, and no adverse reactions were observed in these infants. The combination of Gualou Xiaoyong Decoction and painless lactation manipulation can achieve favorable clinical effects in the treatment of lactational acute mastitis and breast abscess. This combined therapy has good efficacy, short course of treatment, low costs, and great convenience with the avoidance of pain, hospitalization, influence on lactation, breast scar and other adverse outcomes.

Saikosaponin A alleviates Staphylococcus aureus-induced mastitis in mice by inhibiting ferroptosis via SIRT1/Nrf2 pathway.

Mastitis is a common and serious bacterial infection of the mammary gland. Saikosaponin A (SSA) is a triterpenoid saponin isolated from Bupleurum falcatum that has the ability to treat various diseases. However, little is known about the role of SSA in achieving mastitis remission. Here, we found that SSA alleviated Staphylococcus aureus (S. aureus)-induced mastitis by attenuating inflammation and maintaining blood-milk barrier integrity. Furthermore, S. aureus activated nuclear factor kappa B (NF-κB) pathway by upregulated p-p65 and p-IκB. S. aureus also induced ferroptosis in mammary gland in mice, mainly characterized by excessive iron accumulation, mitochondrial morphological changes and impaired antioxidant production. However, S. aureus-induced NF-κB activation and ferroptosis were prevented by SSA. Moreover, SAA could upregulate the expression of SIRT1, Nrf2, HO-1 and GPX4. And the inhibitory effects of SAA on inflammation and ferroptosis were reversed by SIRT1 inhibitor EX-527. In conclusion, SAA protected S. aureus-induced mastitis through suppressing inflammation and ferroptosis by activating SIRT1/Nrf2 pathway.

Diosmetin alleviates S. aureus-induced mastitis by inhibiting SIRT1/GPX4 mediated ferroptosis.

AIMS: Microbial infection is the main factor that induces mastitis. Staphylococcus aureus (S. aureus) is a major pathogen associated with mastitis. The purpose of this study was to investigate the effects of diosmetin on S. aureus-induced mastitis. MATERIALS AND METHODS: The mice were divided into six groups: control group, S. aureus group, diosmetin (12.5, 25, 50 mg/kg) + S. aureus groups, and diosmetin (50 mg/kg) + S. aureus + EX-527 (10 mg/kg) group. S. aureus was injected into the mammary gland to establish a mouse mastitis model. Diosmetin was administered 1 h before S. aureus treatment. KEY FINDINGS: Our results showed that diosmetin significantly alleviated the pathological changes of mammary gland induced by S. aureus. Diosmetin alleviated myeloperoxidase (MPO) activity, and the release of TNF-α and IL-1ß, and nuclear factor kappa-B (NF-κB) activation. Moreover, diosmetin inhibited malondialdehyde (MDA) and Fe2+ levels induced by S. aureus. Diosmetin upregulated ATP, glutathione (GSH) production and glutathione peroxidase 4 (GPX4) expression, which were decreased by S. aureus. Furthermore, the expression of Sirtuin 1 (SIRT1), nuclear factor erythroid2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) was upregulated by diosmetin. In addition, the inhibitory effects of diosmetin on S. aureus-induced inflammation and ferroptosis were prevented by the SIRT1 inhibitor EX-527. SIGNIFICANCE: In conclusion, the data indicated that diosmetin suppressed S. aureus-induced mastitis by attenuating inflammation and ferroptosis.

Maslinic acid alleviates LPS-induced mice mastitis by inhibiting inflammatory response, maintaining the integrity of the blood-milk barrier and regulating intestinal flora.

Mastitis occurs frequently in breastfeeding women and not only affects the women's health but also hinders breastfeeding. Maslinic acid is a type of pentacyclic triterpenoid widely found in olives that has good anti-inflammatory activity. This study aims to discuss the protective function of maslinic acid against mastitis and its underlying mechanism. For this, mice models of mastitis were established using lipopolysaccharide (LPS). The results revealed that maslinic acid reduced the pathological lesions in the mammary gland. In addition, it reduced the generation of pro-inflammatory factors and enzymes (IL-6, IL-1ß, TNF-α, iNOS, and COX2) in both mice mammary tissue and mammary epithelial cells. The high-throughput 16S rDNA sequencing of intestinal flora showed that in mice with mastitis, maslinic acid treatment altered ß-diversity and regulated microbial structure by increasing the abundance of probiotics such as Enterobacteriaceae and downregulating harmful bacteria such as Streptococcaceae. In addition, maslinic acid protected the blood-milk barrier by maintaining tight-junction protein expression. Furthermore, maslinic acid downregulated mammary inflammation by inhibiting the activation of NLRP3 inflammasome, AKT/NF-κB, and MAPK signaling pathways. Thus, in a mice model of LPS-induced mastitis, maslinic acid can inhibit the inflammatory response, protect the blood-milk barrier, and regulate the constitution of intestinal flora.

Phytosphingosine alleviates Staphylococcus aureus-induced mastitis by inhibiting inflammatory responses and improving the blood-milk barrier in mice.

Mastitis is one of the common diseases in dairy cows which threatens the health of cows and impacts on economic benefits seriously. Recent studies have been showed that Subacute Ruminal Acidosis (SARA) increased the susceptibility of cow mastitis. SARA leads the disturbance of the rumen microbiota, and the rumen bacterial disordered community is an important endogenous factor of cow mastitis. That is to say, cows which suffer from SARA have a disordered rumen microbiota, a prolonged decline in ruminal PH and a high level of lipopolysaccharide (LPS) in the rumen, blood. Therefore, ruminal metabolism is closely related to the rumen microbiota. However, the specific mechanism of SARA and mastitis still not clear. We found an intestinal metabolite according to the metabonomics, which is correlated to inflammation. Phytophingosine (PS), a product from rumen fluid and milk of the cows which suffer from SARA and mastitis. It has the effect of killing bacteria and anti-inflammatory. Emerging evidences indicate that PS can alleviate inflammatory diseases. However, how PS affects mastitis is largely unknown. In this study, we explored the concrete role of PS on Staphylococcus aureus (S. aureus) -induced mastitis in mice. We found that PS obviously decreased the level of the proinflammatory cytokines. Meanwhile, PS also significantly relieved the mammary gland inflammation caused by S. aureus and restored the function of the blood-milk barrier. Here, we showed that PS increased the expression of the classic Tight-junctions (TJs) proteins including ZO-1, Occludin and Claudin-3. Moreover, PS improves S. aureus-induced mastitis by inhibiting the activation of the NF-κB and NLRP3 signaling pathways. These data indicated that PS relieved S. aureus-induced mastitis effectively. This also provides a reference for exploring the correlation between the intestinal metabolism and inflammation.

Protocatechuic acid inhibits LPS-induced mastitis in mice through activating the pregnane X receptor.

Mastitis refers to the inflammation in the mammary gland caused by various reasons. Protocatechuic acid (PCA) exerts anti-inflammatory effect. However, no studies have shown the protective role of PCA on mastitis. We investigated the protective effect of PCA on LPS-induced mastitis in mice and elucidated its possible mechanism. LPS-induced mastitis model was established by injection of LPS into the mammary gland. The pathology of mammary gland, MPO activity and inflammatory cytokine production were detected to evaluate the effects of PCA on mastitis. In vivo, PCA significantly attenuated LPS-induced mammary pathological changes, MPO activity, TNF-α and IL-1ß production. In vitro, the production of inflammatory cytokines TNF-α and IL-1ß was significantly reduced by PCA. Furthermore, LPS-induced NF-κB activation was also inhibited by PCA. In addition, PCA was found to activate pregnane X receptor (PXR) transactivation and PCA dose-dependently increased the expression of PXR downstream molecule CYP3A4. In addition, the inhibitory effect of PCA on inflammatory cytokine production was also reversed when PXR was knocked down. In conclusion, the protective effects of PCA on LPS-induced mastitis in mice through regulating PXR.