Synergistic Effect of Eugenol and Probiotic Lactobacillus Plantarum Zs2058 Against Salmonella Infection in C57bl/6 Mice

Potential Involvement of Reactive Oxygen Species in the Bactericidal Activity of Eugenol against Salmonella Typhimurium

There is an increasing need to develop alternative antimicrobials to replace currently used antibiotics. Phytochemicals, such as essential oils, have garnered significant attention in recent years as potential antimicrobials. However, the mechanisms underlying their bactericidal activities are not yet fully understood. In this study, we investigated the bactericidal activity of eugenol oil against Salmonella enterica serovar Typhimurium (S. Typhimurium) to elucidate its mechanism of action. We hypothesized that eugenol exerts its bactericidal effects through the production of reactive oxygen species (ROS), which ultimately leads to cell death. The result of this study demonstrated that the bactericidal activity of eugenol against S. Typhimurium was significantly (p < 0.05) mitigated by thiourea (ROS scavenger) or iron chelator 2,2'-dipyridyl, supporting the hypothesis. This finding contributes to a better understanding of the killing mechanism by eugenol oil.

Monoterpenoid synergy: a new frontier in biological applications

Monoterpenoids, compounds found in various organisms, have diverse applications in various industries. Their effectiveness is influenced by the oil's chemical composition, which in turn is influenced by plant genotype, environmental conditions, cultivation practices, and plant development stage. They are used in various industries due to their distinctive odor and taste, serving as ingredients, additives, insecticides, and repellents. These compounds have synergistic properties, resulting in superior combined effects over discrete ones, potentially beneficial for various health purposes. Many experimental studies have investigated their interactions with other ingredients and their antibacterial, insecticidal, antifungal, anticancer, anti-inflammatory, and antioxidant properties. This review discusses potential synergistic interactions between monoterpenoids and other compounds, their sources, and biological functions. It also emphasizes the urgent need for more research on their bioavailability and toxicity, underlining the importance and relevance of this comprehensive study in the current scientific landscape.

Based on mRNA Sequencing Techniques to Explore the Molecular Mechanism of Buzhong Yiqi Decoction for Autoimmune Thyroiditis

OBJECTIVE

Autoimmune diseases (AD) account for a high percentage of the population. One of the most prevalent is autoimmune thyroiditis (AIT). However, the therapeutic effects of Buzhong Yiqi (BZYQ) decoction on AIT have not been studied yet. The majority of the present study was conducted on NOD.H-2h4 mice in an attempt to ascertain the therapeutic effects of BZYQ decoction on AIT.

METHODS

The 0.05% sodium iodide water (NaI)-induced AIT mice model was established. A total of nine NOD.H-2h4 mice were randomly divided into three groups: the normal group provided with regular water, the model group drinking freely 0.05% NaI, and the treatment group treated with BZYQ decoction (9.56 g/kg) after NaI supplementation (NaI + BZYQ). BZYQ decoction was administered orally once daily for eight weeks. The thyroid histopathology test was used to measure the severity of lymphocytic infiltration. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of anti-thyroglobulin antibody (TgAb), interleukin (IL)-1β, IL-6, and IL-17. The Illumina HiSeq X sequencing platform was utilized to analyze the thyroid tissue by mRNA expression profiles. Bioinformatics analysis was used to investigate the biological function of the differentially expressed mRNAs. In addition, the expression of Carbonyl Reductase 1 (CBR1), 6-Pyruvoyltetrahydropterin Synthase (PTS), Major Histocompatibility Complex, Class II (H2-EB1), Interleukin 23 Subunit Alpha (IL-23A), Interleukin 6 Receptor (IL-6RA), and Janus Kinase 1 (JAK1) was measured by quantitative real-time PCR (qRT-PCR).

RESULTS

The treatment group exhibited significantly lower rates of thyroiditis and lymphocyte infiltration compared to the model group. Serum levels of TgAb, IL-1β, IL-6, and IL-17 were significantly higher in the model group, but they fell dramatically after BZYQ decoction administration. According to our results, 495 genes showed differential expression in the model group compared to the control group. Six hundred twenty-five genes were significantly deregulated in the treatment group compared to the model group. Bioinformatic analysis showed that most mRNAs were associated with immune-inflammatory responses and were involved in multiple signaling pathways, including folate biosynthesis and the Th17 cell differentiation pathway. CBR1, PTS, H2-EB1, IL- 23A, IL-6RA and JAK1 mRNA participated in folate biosynthesis and the Th17 cell differentiation pathway. The qRT-PCR analysis confirmed that the above mRNAs were regulated in the model group compared to the treatment group Conclusion: The results of this investigation have revealed novel insights into the molecular mechanism of action of BZYQ decoction against AIT. The mechanism may be partially attributed to the regulation of mRNA expression and pathways.

Ameliorative avian gut environment and bird productivity through the application of safe antibiotics alternatives: a comprehensive review

The avian digestive tract is an important system for converting ingested food into the nutrients their bodies need for maintenance, growth, and reproduction (meat, table eggs, and fertile eggs). Therefore, preserving digestive system integrity is crucial to bird health and productivity. As an alternative to antibiotics, the world has recently turned to the use of natural products to enhance avian development, intestinal health, and production. Therefore, the primary goal of this review is to explain the various characteristics of the avian digestive tract and how to enhance its performance with natural, safe feed additives such as exogenous enzymes, organic acids, photogenic products, amino acids, prebiotics, probiotics, synbiotics, and herbal extracts. In conclusion, the composition of the gut microbiome can be influenced by a number of circumstances, and this has important consequences for the health and productivity of birds. To better understand the connection between pathogens, the variety of therapies available, and the microbiome of the gut, additional research needs to be carried out.

Application of Eugenol in Poultry to Control Salmonella Colonization and Spread

The poultry sector is an essential component of agriculture that has experienced unprecedented growth during the last few decades. It is especially true for the United States, where the average intake of chicken meat increased from 10 pounds (4.5 kg) per person in 1940 to 65.2 pounds (29.6 kg) per person in 2018, while the country produced 113 billion eggs in 2019 alone. Besides providing nutrition and contributing significantly to the economy, chicken is also a natural reservoir of Salmonella, which is responsible for salmonellosis in humans, one of the significant foodborne illnesses around the globe. The increasing use of chicken manure and antibiotics increases the spread of Salmonella and selects for multi-drug resistant strains. Various plant extracts, primarily essential oils, have been investigated for their antimicrobial activities. The multiple ways through which these plant-derived compounds exert their antimicrobial effects make the development of resistance against them unlikely. Eugenol, an aromatic oil primarily found in clove and cinnamon, has shown antimicrobial activities against various pathogenic bacteria. A few reports have also highlighted the anti-Salmonella effects of eugenol in chicken, especially in reducing the colonization by Salmonella Enteritidis and Salmonella Typhimurium, the primary Salmonella species responsible for human salmonellosis. Besides limiting Salmonella infection in chicken, the supplementation of eugenol also significantly improves intestinal health, improving overall well-being. In this review, we highlight the rising incidences of salmonellosis worldwide and the factors increasing its prevalence. We then propose the usage of eugenol as a natural feed supplement for containing Salmonella in chicken.

Lactobacilli, a Weapon to Counteract Pathogens through the Inhibition of Their Virulence Factors

To date, several studies have reported an alarming increase in pathogen resistance to current antibiotic therapies and treatments. Therefore, the search for effective alternatives to counter their spread and the onset of infections is becoming increasingly important.

Cocktail of isobavachalcone and curcumin enhance eradication of Staphylococcus aureus biofilm from orthopedic implants by gentamicin and alleviate inflammatory osteolysis

Orthopedic device-related infection (ODRI) caused by Staphylococcus aureus, especially methicillin-resistant S. aureus (MRSA) biofilm may lead to persist infection and severe inflammatory osteolysis. Previous studies have demonstrated that both isobavachalcone and curcumin possess antimicrobial activity, recent studies also reveal their antiosteoporosis, anti-inflammation, and immunoregulatory effect. Thus, this study aims to investigate whether the combination of isobavachalcone and curcumin can enhance the anti-S. aureus biofilm activity of gentamicin and alleviate inflammatory osteolysis in vivo. EUCAST and a standardized MBEC assay were used to verify the synergy between isobavachalcone and curcumin with gentamicin against planktonic S. aureus and its biofilm in vitro, then the antimicrobial and immunoregulatory effect of cocktail therapy was demonstrated in a femoral ODRI mouse model in vivo by μCT analysis, histopathology, quantification of bacteria in bone and myeloid-derived suppressor cell (MDSC) in bone marrow. We tested on standard MSSA ATCC25923 and MRSA USA300, 5 clinical isolated MSSA, and 2 clinical isolated MRSA strains and found that gentamicin with curcumin (62.5–250 μg/ml) and gentamicin with isobavachalcone (1.56 μg/ml) are synergistic against planktonic MSSA, while gentamicin (128 μg/ml) with curcumin (31.25–62.5, 250–500 μg/ml) and gentamicin (64–128 μg/ml) with isobavachalcone (1.56–12.5 μg/ml) exhibit synergistic effect against MSSA biofilm. Results of further study revealed that cocktail of 128 μg/ml gentamicin together with 125 μg/ml curcumin +6.25 μg/ml isobavachalcone showed promising biofilm eradication effect with synergy against USA300 biofilm in vitro. Daily intraperitoneal administration of 20 mg/kg/day isobavachalcone, 20 mg/kg/day curcumin, and 20 mg/kg/day gentamicin, can reduce inflammatory osteolysis and maintain microarchitecture of trabecular bone during orthopedic device-related MRSA infection in mice. Cocktail therapy also enhanced reduction of MDSC M1 polarization in peri-implant tissue, suppression of MDSC amplification in bone marrow, and Eradication of USA300 biofilm in vivo. Together, these results suggest that the combination of isobavachalcone and curcumin as adjuvants administrated together with gentamicin significantly enhances its antimicrobial effect against S. aureus biofilm, and can also modify topical inflammation in ODRI and protect bone microstructure in vivo, which may serve as a potential treatment strategy, especially for S. aureus induced ODRI.

Protective Effects of Cinnamaldehyde on the Oxidative Stress, Inflammatory Response, and Apoptosis in the Hepatocytes of Salmonella Gallinarum-Challenged Young Chicks

The development of novel therapeutics to treat multidrug-resistant pathogenic infections like Salmonella gallinarum is the need of the hour. Salmonella infection causes typhoid fever, jaundice, and Salmonella hepatitis resulting in severe liver injury. Natural compounds have been proved beneficial for the treatment of these bacterial infections. The beneficial roles of cinnamaldehyde due to its antibacterial, anti-inflammatory, and antioxidative properties have been determined by many researchers. However, alleviation of liver damage caused by S. gallinarum infection to young chicks by cinnamaldehyde remains largely unknown. Therefore, this study was performed to identify the effects of cinnamaldehyde on ameliorating liver damage in young chicks. Young chicks were intraperitoneally infected with S. gallinarum and treated with cinnamaldehyde orally. Liver and serum parameters were investigated by qRT-PCR, ELISA kits, biochemistry kits, flow cytometry, JC-1 dye experiment, and transcriptome analysis. We found that ROS, cytochrome c, mitochondrial membrane potential (Ψm), caspase-3 activity, ATP production, hepatic CFU, ALT, and AST, which were initially increased by Salmonella infection, significantly ( $P<0.05$ ) decreased by cinnamaldehyde treatment at 1, 3, and 5 days postinfection (DPI). In addition, S. gallinarum infection significantly increased proinflammatory gene expression (IL-1β, IL-6, IL-12, NF-κB, TNF-α, and MyD-88) and decreased the expression of anti-inflammatory genes (IL-8, IL-10, and iNOS); however, cinnamaldehyde reverted these effects at 1, 3, and 5 DPI. Transcriptome analysis showed that S. gallinarum modulates certain genes of the AMPK-mTOR pathway for its survival and replication, and these pathway modulations were reversed by cinnamaldehyde treatment. We concluded that cinnamaldehyde ameliorates inflammation and apoptosis by suppressing NF-Kβ/caspase-3 pathway and reverts the metabolic changes caused by S. gallinarum infection via modulating the AMPK-mTOR pathway. Furthermore, cinnamaldehyde has antibacterial, anti-inflammatory, antioxidative, and antiapoptotic properties against S. gallinarum-challenged young chicks and can be a candidate novel drug to treat salmonellosis in poultry production.

Dietary supplementation with low-dose xylooligosaccharide promotes the anti-Salmonella activity of probiotic Lactiplantibacillus plantarum ZS2058 in a murine model

Oligosaccharides have been previously reported to cause an aggravation of Salmonella infection. In this study, we reduced the dietary supplementation of oligosaccharides (1% w/w) and studied their effects on the anti-Salmonella activity of probiotic Lactiplantibacillus plantarum (L. plantarum) ZS2058. The results showed that among all five studied oligosaccharides, only xylooligosaccharide (XOS) promoted the anti-Salmonella activity of L. plantarum ZS2058 by increasing the survival rate of the infected mice (66.7% vs. 53.3%). Further study revealed that XOS did not function synergistically with L. plantarum ZS2058, as XOS itself did not improve the survival rate of the infected mice. In an in vitro coculture system, XOS significantly promoted the antagonistic activity (92% increase) of L. plantarum ZS2058 against Salmonella. In Salmonella-infected mice, the combination of XOS and L. plantarum ZS2058 significantly increased the faecal content of short-chain fatty acids (SCFAs) and restored the production of proinflammatory cytokines. More importantly, XOS, L. plantarum ZS2058 and their combination changed the gut microbiota into distinct profiles. Linear Discriminant Analysis (LDA) effect size (LEfSe) analysis identified five taxa as marker bacteria for mice treated with a combination of XOS and L. plantarum ZS2058. In particular, Mucispirillum, which was previously reported to protect the host from Salmonella infection, was increased. Here, we showed that low dose XOS could promote the anti-Salmonella activity of the probiotic L. plantarum ZS2058. These results offer new opportunities to cope with this predominant food-borne pathogen with great efficiency and to lay a foundation for developing functional foods with anti-Salmonella potential.

Protective Effects of Cinnamaldehyde on the Inflammatory Response, Oxidative Stress, and Apoptosis in Liver of Salmonella typhimurium-Challenged Mice

Salmonella typhimurium infection is associated with gastrointestinal disorder and cellular injury in the liver of both humans and animals. Cinnamaldehyde, the main component of essential oil from cinnamon, has been reported to have anti-inflammatory, anti-oxidative, and anti-apoptotic effects. However, it remains unknown whether cinnamaldehyde can alleviate Salmonella typhimurium infection-induced liver injury in mice. In the present study, we found that cinnamaldehyde attenuated Salmonella typhimurium-induced body weight loss, the increase of organ (liver and spleen) indexes, hepatocyte apoptosis, and the mortality rate in mice. Further study showed that cinnamaldehyde significantly alleviated Salmonella typhimurium-induced liver injury as shown by activities of alanine transaminase, aspartate transaminase, and myeloperoxidase, as well as malondialdehyde. The increased mRNA level of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and chemokines (CCL2 and CCL3) induced by Salmonella typhimurium were significantly abolished by cinnamaldehyde supplementation. These alterations were associated with a regulatory effect of cinnamaldehyde on TLR2, TLR4, and MyD88. 16S rDNA sequence analysis showed that Salmonella typhimurium infection led to upregulation of the abundances of genera Akkermansia, Bacteroides, Alistipes, Muribaculum, and Prevotellaceae UCG-001, and downregulation of the abundances of genera Lactobacillus, Enterorhabdus, and Eggerthellaceae (unclassified). These alterations were reversed by cinnamaldehyde supplementation. In conclusion, cinnamaldehyde attenuated the inflammatory response, oxidative stress, and apoptosis in the liver of Salmonella typhimurium-infected mice. Supplementation of cinnamaldehyde might be a preventive strategy to alleviate liver injury caused by Salmonella typhimurium infection in humans and animals.