Effects of Chinese Propolis in Protecting Bovine Mammary Epithelial Cells against Mastitis Pathogens-Induced Cell Damage

Bee-Inspired Healing: Apitherapy in Veterinary Medicine for Maintenance and Improvement Animal Health and Well-Being

This review aims to present current knowledge on the effects of honey bee products on animals based on in vivo studies, focusing on their application in clinical veterinary practice. Honey's best-proven effectiveness is in treating wounds, including those infected with antibiotic-resistant microorganisms, as evidenced in horses, cats, dogs, mice, and rats. Propolis manifested a healing effect in numerous inflammatory and painful conditions in mice, rats, dogs, and pigs and also helped in oncological cases in mice and rats. Bee venom is best known for its effectiveness in treating neuropathy and arthritis, as shown in dogs, mice, and rats. Besides, bee venom improved reproductive performance, immune response, and general health in rabbits, chickens, and pigs. Pollen was effective in stimulating growth and improving intestinal microflora in chickens. Royal jelly might be used in the management of animal reproduction due to its efficiency in improving fertility, as shown in rats, rabbits, and mice. Drone larvae are primarily valued for their androgenic effects and stimulation of reproductive function, as evidenced in sheep, chickens, pigs, and rats. Further research is warranted to determine the dose and method of application of honey bee products in animals.

Propolis Alleviates Acute Lung Injury Induced by Heat-Inactivated Methicillin-Resistant Staphylococcus aureus via Regulating Inflammatory Mediators, Gut Microbiota and Serum Metabolites

Propolis has potential anti-inflammatory properties, but little is known about its efficacy against inflammatory reactions caused by drug-resistant bacteria, and the difference in efficacy between propolis and tree gum is also unclear. Here, an in vivo study was performed to study the effects of ethanol extract from poplar propolis (EEP) and poplar tree gum (EEG) against heat-inactivated methicillin-resistant Staphylococcus aureus (MRSA)-induced acute lung injury (ALI) in mice. Pre-treatment with EEP and EEG (100 mg/kg, p.o.) resulted in significant protective effects on ALI in mice, and EEP exerted stronger activity to alleviate lung tissue lesions and ALI scores compared with that of EEG. Furthermore, EEP significantly suppressed the levels of pro-inflammatory mediators in the lung, including TNF-α, IL-1β, IL-6, and IFN-γ. Gut microbiota analysis revealed that both EEP and EEG could modulate the composition of the gut microbiota, enhance the abundance of beneficial microbiota and reduce the harmful ones, and partly restore the levels of short-chain fatty acids. EEP could modulate more serum metabolites and showed a more robust correlation between serum metabolites and gut microbiota. Overall, these results support the anti-inflammatory effects of propolis in the treatment of ALI, and the necessity of the quality control of propolis.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by caffeic acid phenethyl ester, a major component of Chinese propolis

OBJECTIVES

We evaluated the immune-modulatory effects of Chinese propolis (CP) and its major constituent, caffeic acid phenethyl ester (CAPE), on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells.

METHODS

Mouse spleen cells stimulated by anti-CD3 monoclonal antibody were co-cultured with CP, CAPE, and HC030031, a specific antagonist of the TRPA1 Ca2+-permeable cation channel. Cytokine production was assayed by enzyme-linked immunosorbent assay. Interleukin (IL)-2 mRNA expression was examined by reverse transcription-quantitative polymerase chain reaction.

RESULTS

In stimulated spleen cells treated with 1/16,000 CP diluent, IL-2 production was markedly enhanced, while IL-4 and IL-10 productions were not significantly affected. In contrast, interferon (IFN)-γ, IL-6, and IL-17 productions were markedly reduced. These effects of CP were reproduced by the CAPE treatment. A time-course observation demonstrated that, compared to control cells, IL-2 mRNA expression and production were significantly enhanced in the spleen cells stimulated by CAPE; however, IL-2 production was markedly delayed compared to that in the untreated control cells. The enhancement of IL-2 production by CAPE was scarcely alleviated by the addition of HC030031. These effects of CAPE upon IL-2 mRNA production were abolished in spleen cells without anti-CD3 antibody stimulation.

CONCLUSIONS

CAPE is an important regulator of CP for cytokine regulation in anti-CD3 antibody-stimulated spleen cells. The agent specifically reduced IFN-γ, IL-6, and IL-17 and slightly enhanced Th2 cytokine production while significantly enhancing IL-2 production at the transcriptional level.

Increased Milk Yield and Reduced Enteric Methane Concentration on a Commercial Dairy Farm Associated with Dietary Inclusion of Sugarcane Extract (Saccharum officinarum)

(1) Background: The purpose of this study was to assess the influence of a natural sugarcane extract (Polygain™) on milk production, milk composition and methane emissions on a commercial dairy farm. (2) Methods: A three-week baseline was established for lactating Holstein × Friesian animals. Following this baseline period, these animals were fed Polygain™ at 0.25% of their estimated dry matter intake for 3 weeks. Methane concentration in the feed bin was determined at each milking using the Gascard NG Infrared Sensor (Edinburgh Sensors LTD). (3) Results: During the intervention phase milk yield increased significantly from 26.43 kg to 28.54 kg per cow per day, whilst methane emissions and bulk tank somatic cell counts decreased significantly in the intervention phase. For methane concentration, an average of 246 ppm during the baseline periods reduced to an average of 161.09 ppm during the intervention phase. For the bulk tank somatic cell counts, the average was observed at 283,200 during the baseline and reduced to an average value of 151,100 during the intervention phase. (4) Conclusions: The natural sugarcane extract was shown to have the potential to mitigate enteric methane emissions while also increasing production and animal wellbeing outcomes in a commercial dairy setting.

Study the Mechanism of Gualou Niubang Decoction in Treating Plasma Cell Mastitis Based on Network Pharmacology and Molecular Docking

Objective

Explore the potential molecular mechanisms behind the therapeutic functions of Gualou Niubang decoction (GLNBD) in the treatment of plasma cell mastitis (PCM) by network pharmacology and molecular docking.

Methods

GLNBD is a formula of Chinese traditional medicine consisting of 12 herbs. The potential active ingredients of GLNBD and their target genes were obtained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform database, and PCM-related target genes were obtained from GeneCards, OMIM, and NCBI databases, using R language to obtain intersection targets; then, the STRING database and Cytoscape software were used to establish protein-protein interaction networks and herb ingredient target networks. DAVID was used to perform GO and KEGG pathway enrichment analyses on the intersection target. PyMoL-2.5.0 and AutoDock Tools-1.5.6 were used to verify the molecular docking.

Results

164 ingredients and 58 intersection targets were obtained in the treatment of PCM by GLNBD. Four key active compounds and four key proteins were identified. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses showed that biological functions of potential target genes were associated with negative regulation of the apoptotic process, response to hypoxia, positive regulation of transcription, and DNA-templated, with related pathways involving the pathway in cancer, phosphatidylinositol 3-kinase (PI3K) Akt signaling pathway, and AGE-RAGE signaling pathway in diabetic complications. Moreover, the binding activities of key target genes and essential active compounds of Chinese herbal medicines in GLNBD were further validated by molecular docking. The results showed that the docking results were stable and had good binding ability.

Conclusion

This study suggested that four potential key active components, including quercetin, luteolin, fisetin, and kaempferol, were identified in GLNBD, which could interact with ALB, EGFR, IL-6, and VEGFA modulating the activation of the pathway in cancer, PI3K-Akt pathway, and AGE-RAGE signaling pathway in diabetic complications.

Exploring the Action Mechanism of the Active Ingredient of Quercetin in Ligustrum lucidum on the Mouse Mastitis Model Based on Network Pharmacology and Molecular Biology Validation

Aim

The aim of this study is to explore the mechanism of action of quercetin, the main active anti-inflammatory component of Ligustrum lucidum, in the prevention and treatment of mastitis.

Methods

Prediction of the main active ingredients and key anti-inflammatory targets of Ligustrum lucidum using a network pharmacology platform and molecular biology validation of the results. Observation of histopathological changes in the mouse mammary gland by hematoxylin-eosin staining(H&E) method, quantitative real-time PCR(qPCR), and Western blot (WB) to detect the expression levels of relevant inflammatory factors mRNA and protein.

Results

A total of 7 active ingredients and 42 key targets were obtained from the network pharmacological analysis of Ligustrum lucidum, with quercetin as the main core ingredient and tumor necrosis factor(TNF), serine threonine protein kinase1(AKT1), and interleukin6(IL6) as the core targets; H&E results showed that pathological changes were reduced to different degrees in the dose group compared to the model group. The qPCR results showed that the relative expression of TNF and IL6 mRNA in the high dose group on day 3 and the high and medium dose groups on day 7 were not significantly different compared with the blank group (P > 0.05), and the difference between the dose groups on day 5 was significant (P < 0.05). WB results showed that the difference in nuclear factor kappa-B(NF-κB) protein expression in the medium and low dose groups on day 7 was significant compared with the blank group (P < 0.05), the difference in 5 and 7 days, significant differences in AKT1 protein expression between the middle and low dose groups (P < 0.05), nonsignificant differences in the TNF protein expression between the high dose groups on day 7 (P > 0.05), and significant differences in the IL6 protein expression between the middle and low dose groups on days 3 and 7 (P < 0.05).

Conclusion

Quercetin, the main active ingredient of Ligustrum lucidum, may act in the prevention and treatment of mastitis by inhibiting the expression of inflammatory factors in phosphoinositol 3-kinase(PI3K)-AKT and NF-κB signaling pathways and showa a significant dose-dependent effect. This study provides theoretical basis and clues for the control of mastitis in dairy cows.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by artepillin C, a major component of Brazilian green propolis

OBJECTIVES

In this report, we attempt to clarify the immune modulatory effects of Brazilian green propolis (BGP) and its major component, artepillin C, on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells. We also estimate the physiological mechanism affecting artepillin C's upon the cells.

METHODS

Male C3H/HeN mouse spleen cells stimulated by antiCD3 monoclonal antibody were co-cultured with BGP, artepillin C, and HC030031, a transient receptor potential ankyrin 1 (TRPA1) Ca²⁺ channel antagonist. The synthesis of interferon (IFN)-γ, interleukin (IL)-6, IL-17, IL-4, IL-10, and IL-2 was assayed by enzyme-linked immunoassay. The expression of IL-2 mRNA and the protein product were examined by reverse transcription-quantitative polymerase chain reaction and Western blot analyses, respectively.

RESULTS

The production of IL-2 was markedly enhanced, while that of IL-4 and IL-10 was not significantly affected; by contrast, the production of IFN-γ, IL-6, and IL-17 was significantly reduced in the antibody-stimulated spleen cells treated with BGP at a non-cytostatic concentration. These effects were reproduced in the cells treated with artepillin C. The expression of IL-2 mRNA was unaffected; however, that of the protein was significantly enhanced in the artepillin C-treated cells compared to untreated control cells. The enhancement of protein expression and the production of IL-2 by artepillin C was significantly alleviated by adding HC030031.

CONCLUSIONS

Artepillin C is an important regulator of cytokine synthesis from activated spleen cells. The agent specifically augmented the expression of IL-2 via the Ca²⁺-permeable cation channel, TRPA1, at least in part, at the translational or secretion levels.

Selenium Alleviates Inflammation in Staphylococcus aureus-Induced Mastitis via MerTK-Dependent Activation of the PI3K/Akt/mTOR Pathway in Mice

Mastitis caused by Staphylococcus aureus infection not only causes serious economic losses, but also affects human health. Se plays an important role in body immunity. However, the mechanisms by which Se regulates mastitis induced by S. aureus are still principally unknown. The purpose of this study is to investigate whether Se can inhibit mastitis induced by S. aureus through regulation of MerTK. Sixty BALB/c female mice were fed low, normal, or high Se concentrations for 7 weeks and then randomly divided into six groups (Se-Low Control group (LSN), Se-Normal Control group (NSN), Se-High Control group (HSN), Se-Low S. aureus group (LSS), Se-Normal S. aureus group (NSS), Se-High S. aureus group (HSS)). The regulation of Se on MerTK was detected via histopathological staining, western blot analysis, enzyme-linked immunosorbent assay, and qRT-PCR. With increased selenium concentrations, the levels of IL-1β, IL-6, and TNF-α decreased, while the phosphorylation levels of MerTK, PI3K, AKT, and mTOR increased. Therefore, this study showed that Se could alleviate S. aureus mastitis by activating MerTK and PI3K/AKT/mTOR pathway.

An overview on mastitis-associated Escherichia coli: Pathogenicity, host immunity and the use of alternative therapies

Escherichia coli is one of the leading causes of bovine mastitis; it can cause sub-clinical, and clinical mastitis characterized by systemic changes, abnormal appearance of milk, and udder inflammation. E. coli pathogenicity in the bovine udder is due to the interaction between its virulence factors and the host factors; it was also linked to the presence of a new pathotype termed mammary pathogenic E. coli (MPEC). However, the presence of this pathotype is commonly debated. Its main virulence factor is the lipopolysaccharide (LPS) that is responsible for causing an endotoxic shock, and inducing a strong immune response by binding to the toll-like receptor 4 (TLR4), and stimulating the expression of chemokines (such as IL-8, and RANTES) and pro-inflammatory cytokines (such as IL-6, and IL-1β). This strong immune response could be used to develop alternative and safe approaches to control E. coli causing bovine mastitis by targeting pro-inflammatory cytokines that can damage the host tissue. The need for alternative treatments against E. coli is due to its ability to resist many conventional antibiotics, which is a huge challenge for curing ill animals. Therefore, the aim of this review was to highlight the pathogenicity of E. coli in the mammary gland, discuss the presence of the new putative pathotype, the mammary pathogenic E. coli (MPEC) pathotype, study the host's immune response, and the alternative treatments that are used against mastitis-associated E. coli.

Effects of Pasture Type on Metabolism, Liver and Kidney Function, Antioxidant Status, and Plant Secondary Compounds in Plasma of Grazing, Jersey Dairy Cattle During Mid-lactation

Some pasture species are rich in phytochemicals, able to improve milk yield and quality and to reduce the environmental impacts of livestock farming. The phytochemicals interact with the different gene networks within the animal, such as nuclear factor erythroid 2-related factor 2 (NRF2), but their overall impact on animal health remains to be fully understood. The objective of this study was to identify the effects of pasture Legumes and non-leguminous Forbs containing high bioactive compounds on metabolism and activity of the liver, antioxidant response, kidney function, and inflammation of dairy cows using a large array of blood parameters associated with metabolism and the innate immune system. For this purpose, 26 parameters and the concentration of certain bioactive compounds were assessed in blood plasma, collected from the Jersey cows grazing either Grass, Legume, or Forb-based pastures. In addition, serum collected from all the cows was utilized to detect the changes in NRF2 activation in bovine mammary alveolar cells (MACT) and hepatocytes. Compared with Grass, the cows that grazed both Forb and Legume pastures had lower β-hydroxybutyric acid (BHB) and creatinine and larger vitamin E and the ferric reducing ability of the plasma, supporting an improved antioxidative status for these animals. Compared with both Grass and Legume, the cows that graze Forb pasture had lower urea and urea to creatinine ratio, and lower creatinine, indicating a better kidney function. The cows grazing Legume pasture had greater hematocrit, bilirubin, cholesterol, albumin, β-carotene, retinol, and thiol groups but lower ceruloplasmin, paraoxonase, and myeloperoxidase (MPO) than those grazed Grass and Forb pastures, indicating a positive effect of Legume pasture on the liver, oxidative stress, and red blood cells. The plasma of cows in the various pastures was enriched with various isoflavonoids, especially the cows grazed on Forb and Legume pastures, which likely contributed to improving the antioxidative status of those cows. However, this effect was likely not due to the higher activation of NRF2. Overall, these results indicate that Forb and Legume pastures rich in secondary metabolites do not strongly affect the metabolism but can improve the status of the liver and the kidney and improve the efficiency of N utilization and antioxidant response, compared with the Grass pasture.

Experimental Evidence for Therapeutic Potentials of Propolis

Propolis is produced by honeybees from materials collected from plants they visit. It is a resinous material having mixtures of wax and bee enzymes. Propolis is also known as bee glue and used by bees as a building material in their hives, for blocking holes and cracks, repairing the combs and strengthening their thin borders. It has been extensively used since ancient times for different purposes in traditional human healthcare practices. The quality and composition of propolis depend on its geographic location, climatic zone and local flora. The New Zealand and Brazilian green propolis are the two main kinds that have been extensively studied in recent years. Their bioactive components have been found to possess a variety of therapeutic potentials. It was found that Brazilian green propolis improves the cognitive functions of mild cognitive impairments in patients living at high altitude and protects them from neurodegenerative damage through its antioxidant properties. It possesses artepillin C (ARC) as the key component, also known to possess anticancer potential. The New Zealand propolis contains caffeic acid phenethyl ester (CAPE) as the main bioactive with multiple therapeutic potentials. Our lab performed in vitro and in vivo assays on the extracts prepared from New Zealand and Brazilian propolis and their active ingredients. We provided experimental evidence that these extracts possess anticancer, antistress and hypoxia-modulating activities. Furthermore, their conjugation with γCD proved to be more effective. In the present review, we portray the experimental evidence showing that propolis has the potential to be a candidate drug for different ailments and improve the quality of life.

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.

Effects of Hydroxytyrosol against Lipopolysaccharide-Induced Inflammation and Oxidative Stress in Bovine Mammary Epithelial Cells: A Natural Therapeutic Tool for Bovine Mastitis

Background: Bovine mastitis is a growing health problem, affecting both welfare of dairy cattle and milk production. It often leads to chronic infections, disturbing the quality of milk and resulting in cow death. Thus, it has a great economic impact for breeders. Methods: In this study, we evaluated the protective effect of hydroxytyrosol—a natural molecule which is the major constituent of many phyto-complexes—in an in vitro model of mastitis induced by LPS (1μg/mL). Results: Our results showed that hydroxytyrosol (10 and 25 μM) was able to prevent the oxidative stress induced by LPS (intracellular ROS, GSH and NOX-1) and the consequently inflammatory response (TNF-α, IL-1β and IL-6). The protective effect of hydroxytyrosol is also related to the enhancement of endogenous antioxidant systems (Nrf2, HO-1, NQO-1 and Txnrd1). Moreover, hydroxytyrosol showed an important protective effect on cell functionality (α-casein S1, α-casein S2 and β-casein). Conclusions: Taken together, our results showed a significant protective effect of hydroxytyrosol on oxidative stress and inflammatory response in MAC-T cells. Thus, we indicated a possible important therapeutic role for hydroxytyrosol in the prevention or management of bovine mastitis.

Antibiotic-Antiapoptotic Dual Function of Clinacanthus nutans (Burm. f.) Lindau Leaf Extracts against Bovine Mastitis

Mastitis caused by bacterial infection has negative impacts on milk quality and animal health, and ultimately causes economic losses to the dairy industry worldwide. Gram-negative bacteria and their component lipopolysaccharide (LPS) can trigger the inflammatory response of endothelial cells (ECs) and subsequently promote EC dysfunction or injury, which is a critical pathogenesis of mastitis-causing sepsis shock. To control the bacterial infection and to minimise the LPS negative effects on ECs, we thus aimed to identify the potential herb extracts that comprised antibacterial activity and protective ability to inhibit LPS-induced cell death. Extracts from seven types of herbs derived from antibacterial screening were investigated for their protective effects on LPS-stimulated bovine endothelial cell line. Clinacanthus nutans (Burm. f.) Lindau (C. nutans) extract appeared to be the most effective antiapoptotic extract against LPS stimulation. Treatment of C. nutans extract in LPS-stimulated cells significantly lowered apoptotic cell death through modulating pro-survival Bcl-2 and pro-apoptotic Bax expression. The investigation of bioactive compounds using solvent fractionation, HPLC, and LC-MS/MS analysis revealed glyceryl 1,3-disterate (C₃₉H₇₆O₅), kaempferol 3-O-feruloyl-sophoroside 7-O-glucoside (C₄₃H₄₈O₂₄), and hydroxypthioceranic acid (C₄₆H₉₂O₃) as the candidate components. Our findings indicated that C. nutans extract has great potential to be further developed as an alternative therapeutic agent for mastitis treatment.

Identification of Gene Modules and Hub Genes Involved in Mastitis Development Using a Systems Biology Approach

Objective

Mastitis is defined as the inflammation of the mammary gland, which impact directly on the production performance and welfare of dairy cattle. Since, mastitis is a multifactorial complex disease and the molecular pathways underlying this disorder have not been clearly understood yet, a system biology approach was used in this study to a better understanding of the molecular mechanisms behind mastitis.

Methods

Publicly available RNA-Seq data containing samples from milk of five infected and five healthy Holstein cows at five time points were retrieved. Gene Co-expression network analysis (WGCNA) approach and functional enrichment analysis were then applied with the aim to find the non-preserved module of genes that their connectivity were altered under infected condition. Hub genes were identified in the non-preserved modules and were subjected to protein-protein interactions (PPI) network construction.

Results

Among the 25 modules identified, eight modules were non-preserved and were also biologically associated with inflammation, immune response and mastitis development. Interestingly most of the hub genes in the eight modules were also densely connected in the PPI network. Of the hub genes, 250 genes were hubs in both co-expression and PPI networks and most of them were reported to play important roles in immune response or inflammatory pathways. The blue module was highly enriched in inflammatory responses and STAT1 was suggested to play an important role in mastitis development by regulating the immune related genes in this module. Moreover, a set of highly connected genes were identified such as BIRC3, PSMA6, FYN, F11R, NFKBIZ, NFKBIA, GRO1, PHB, CD3E, IL16, GSN, SOCS2, HCK, VAV1 and TLR6, which have been established to be critical for mastitis pathogenesis.

Conclusion

This study improved the understanding of the mechanisms underlying bovine mastitis and suggested eight non-preserved modules along with several most important genes with promising potential in etiology of mastitis.

Short communication: Effects of moringa extract on adhesion and invasion of Escherichia coli O55 in bovine mammary epithelial cells

The objective of this study was to evaluate the antibacterial activities of extract derived from moringa leaves. In particular, the effect of moringa extract (Mor) on adhesion and invasion of Escherichia coli O55, Enterococcus faecalis, Staphylococcus simulans, and Serratia liquefaciens was evaluated in bovine mammary epithelial cells (MAC-T). Broth microdilution method, minimum inhibitory concentration and minimum bactericidal concentration assays, adhesion and invasion assays, and real-time PCR were performed. The minimum inhibitory concentration and minimum bactericidal concentration of Mor ranged from 12.5 to 50 mg/mL on 18 out of 27 tested isolates. Treatment of E. coli O55 with Mor (100 and 200 μg/mL) inhibited the adhesion and invasion on MAC-T cells via downregulation of adhesion factors (i.e., papC, f17c-A, and eaeA). Also, when MAC-T cells were pretreated with Mor (200 μg/mL, 12 h) and incubated with E. coli O55, Enterococcus faecalis, Staphylococcus simulans, or Serratia liquefaciens, both E. coli O55 and Enterococcus faecalis showed a significant decrease in adhesion and invasion. Staphylococcus simulans exhibited decreased adhesion and increased invasion. Serratia liquefaciens showed increased adhesion and decreased invasion. In addition, Mor increased mRNA expression of antioxidant enzymes (e.g., heme oxygenase-1, NAD(P)H:quinone oxidoreductase-1, and thioredoxin reductase 1) in MAC-T cells. In conclusion, 12.5 to 50 mg/mL of Mor exhibited antibacterial activity against 18 out of 27 tested isolates. Also, pretreatment of 200 μg/mL of Mor to MAC-T cells modulated adhesion and invasion of E. coli O55 and other mastitis-associated pathogens. Furthermore, Mor increased antioxidant capacities in MAC-T cells, but further in vivo studies are needed.

Bovine mastitis: risk factors, therapeutic strategies, and alternative treatments - A review

Bovine mastitis, an inflammation of the mammary gland, is the most common disease of dairy cattle causing economic losses due to reduced yield and poor quality of milk. The etiological agents include a variety of gram-positive and gram-negative bacteria, and can be either contagious (e.g., Staphylococcus aureus, Streptococcus agalactiae, Mycoplasma spp.) or environmental (e.g., Escherichia coli, Enterococcus spp., coagulase-negative Staphylococcus, Streptococcus uberis). Improving sanitation such as enhanced milking hygiene, implementation of post-milking teat disinfection, maintenance of milking machines are general measures to prevent new cases of mastitis, but treatment of active mastitis infection is dependant mainly on antibiotics. However, the extensive use of antibiotics increased concerns about emergence of antibiotic-resistant pathogens and that led the dairy industries to reduce the use of antibiotics. Therefore, alternative therapies for prevention and treatment of bovine mastitis, particularly natural products from plants and animals, have been sought. This review provides an overview of bovine mastitis in the aspects of risk factors, control and treatments, and emerging therapeutic alternatives in the control of bovine mastitis.

Potential Protective Effects of the Water-Soluble Chinese Propolis on Hypertension Induced by High-Salt Intake

High‐salt (HS) intake is closely associated with the ignition and progression of hypertension. The mechanisms might be involved in endothelial dysfunction, nitric oxide deficiency, oxidative stress, and proinflammatory cytokines. Propolis is widely used as a natural antioxidant and is a well‐known functional food for its biological activities, which includes anti‐inflammation, antimicrobial, and liver detoxification. In this study, we successfully replicated a HS diet‐induced hypertensive rat model. We found that in the long‐term HS diet group, the myocardial function of the rats was altered and led to a significant decrease (around 49%) in heart function. However, doses of Chinese water‐soluble propolis (WSP) were found directly proportional (11%, 60%, 91%, respectively) to the myocardial function improvement in hypertensive rats. The results from the blood circulation test and hematoxylin‐eosin stains showed that propolis had protective effects on myocardial functions and blood vessels in hypertensive rats. Also, based on the results of western blot and polymerase chain reaction, WSP effectively regulated Nox2 and Nox4 levels and was responsible for a decrease in reactive oxygen species synthesis. Our findings demonstrate that Chinese WSP has a significant effect on the blood pressure of hypertensive rats and their cardiovascular functions that improved significantly. The improvement in the cardiovascular functions might be related to the process of anti‐oxidation, anti‐inflammation, and the improvements of the endothelial function in hypertensive rats.

The Wisdom of Honeybee Defenses Against Environmental Stresses

As one of the predominant pollinator, honeybees provide important ecosystem service to crops and wild plants, and generate great economic benefit for humans. Unfortunately, there is clear evidence of recent catastrophic honeybee colony failure in some areas, resulting in markedly negative environmental and economic effects. It has been demonstrated that various environmental stresses, including both abiotic and biotic stresses, functioning singly or synergistically, are the potential drivers of colony collapse. Honeybees can use many defense mechanisms to decrease the damage from environmental stress to some extent. Here, we synthesize and summarize recent advances regarding the effects of environmental stress on honeybees and the wisdom of honeybees to respond to external environmental stress. Furthermore, we provide possible future research directions about the response of honeybees to various form of stressors.

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.