Comparative Proteomic Analysis Reveals Antibacterial Mechanism of Patrinia scabiosaefolia Against Methicillin Resistant Staphylococcus epidermidis

Emilia sonchifolia (L.) DC. inhibits the growth of Methicillin-Resistant Staphylococcus epidermidis by modulating its physiology through multiple mechanisms

Bloodstream infections (BSIs) are a public health concern, causing substantial morbidity and mortality. Staphylococcus epidermidis (S. epidermidis) is a leading cause BSIs. Antibiotics targeting S. epidermidis have been the mainstay of treatment for BSIs, however their efficacy is diminishing in combating with drug-resistant bacteria. Therefore, alternative treatments for antibiotic-resistant infections are urgently required. Studies have demonstrated that certain traditional Chinese medicine (TCM) exhibit notable antimicrobial activity and can help mitigate bacterial resistance. Among these, The ethanol extract of Emilia sonchifolia (L.) DC (E. sonchifolia) (10 g crude drug/1 g extract ) exhibits a noteworthy anti-methicillin-resistant S. epidermidis (MRSE) effect. This study explores antibacterial activity and underlying mechanisms of E. sonchifolia against MRSE. The antibacterial activity of E. sonchifolia against MRSE was assessed in vitro by measuring the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The MRSE-induced mouse BSIs model was used to evaluate the antibacterial activity of E. sonchifolia in vivo. Proteomic and transcriptomic analyses were performed to elucidate the underlying antibacterial mechanisms. The MIC and MBC values of E. sonchifolia against MRSE were 5 mg/mL and 20 mg/mL, respectively. In vivo, E. sonchifolia effectively treated MRSE-induced BSIs. Additionally, proteomic and transcriptomic analyses revealed considerable down-regulation of purine metabolism, that were associated with oxidative stress and cell wall synthesis. The enzyme linked immunosorbent assay(ELISA) results showed decreased levels of inosine monophosphate (IMP), Adenosine monophosphate(AMP) and guanine monophosphate (GMP), indicating inhibited purine metabolism. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis confirmed bacterial cell wall damage. E. sonchifolia exerts antibacterial effects by inhibiting purine metabolism, promoting bacterial oxidative stress, and impairing cell wall synthesis. These findings provide novel insights into the mechanistic understanding of E. sonchifolia's efficacy against MRSE, offering potential strategies for managing MRSE infections.

Comprehensive multi-omics analysis reveals the mechanism of hepatotoxicity induced by Emilia sonchifolia (L.) DC

ETHNOPHARMACOLOGICAL RELEVANCE

Emilia sonchifolia is a very widely used traditional Chinese medicine, with the efficacy of heat-clearing, detoxicating, dissipating blood stasis, reducing swelling and relieving pain. As a widely used traditional miao herb, Emilia sonchifolia is often used to treat upper respiratory tract infections, oral ulcer, pneumonia, mastitis, enteritis, bacillum, urinary tract infection, sores, eczema, falls and injuries, etc. In fact, many cases of liver injury caused by Emilia sonchifolia have been reported clinically. However, the mechanisms underlying hepatotoxicity induced by Emilia sonchifolia remain poorly understood.

AIM OF THE STUDY

This study aimed to systematically evaluate the acute and chronic hepatotoxicity of water extract from Emilia sonchifolia, identify its hepatotoxic metabolites, and elucidate the potential mechanisms underlying Emilia sonchifolia-induced hepatotoxicity.

MATERIAL AND METHOD

The chemical components in the water extract of Emilia sonchifolia were identified using mass spectrometry. The acute toxicity study was conducted by orally administering a gradient dose of water extract of Emilia sonchifolia ranging from 0 to 37.6 g/kg. Mice were orally administered a water extract of Emilia sonchifolia at a dose of 13.72 g/kg/d for 14 days to induce liver injury. The hepatotoxicity was evaluated using hematoxylin and eosin staining as well as enzyme-linked immunosorbent assay (ELISA). The mechanisms of hepatotoxicity were explored through transcriptomics, proteomics, and metabolomics analysis. Meanwhile, the core pathways related to the hepatotoxicity of Emilia sonchifolia were analyzed and validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR) and ELISA.

RESULT

The present study demonstrates that the water extract of Emilia sonchifolia can induce hepatotoxicity in mice. We found that the water extract of Emilia sonchifolia contained hepatotoxic pyrrolizidine alkaloids, such as seneciphyllin, senecionine, rinderine, echimidine, retrorsine and echimidine N-oxide. A dose of 19.20 g/kg or higher of the water extract of Emilia sonchifolia caused acute liver failure and death in mice. A dose of 13.72 g/kg or lower of the water extract of Emilia sonchifolia produced dose-dependent acute hepatotoxicity. Meanwhile, a dose of 13.72 g/kg of the water extract from Emilia sonchifolia induced chronic hepatotoxicity in mice. Furthermore, the results of liver transcriptomics, proteomics, and metabolomics indicate that the mechanism of hepatotoxicity induced by the water extract of Emilia sonchifolia is associated with ferroptosis caused by abnormalities in bile acid accumulation, lipid and bilirubin accumulation, and glutathione metabolism. The validation experiment results demonstrate that in mice treated with the water extract of Emilia sonchifolia, the gene levels of Cyp2c29, Cyp3a41a and Ugt2b1 decreased while the gene level of Hsd3b3 increased. In mice treated with a water extract of Emilia sonchifolia, the levels of total bilirubin, direct bilirubin, total bile acids, alkaline phosphatase, and γ-glutamyl transferase were significantly elevated. Additionally, in mice treated with a water extract of Emilia sonchifolia, the levels of malondialdehyde increased while the levels of catalase and superoxide dismutase decreased.

CONCLUSION

In conclusion, our results suggest that the water extract of Emilia sonchifolia can cause hepatotoxicity in mice. The chronic hepatotoxicity of Emilia sonchifolia is associated with Cyp2c29, Cyp3a41a, Ugt2b1, and Hsd3b3-mediated cholestasis, oxidative stress, and ferroptosis.

Comparative Metabolomics Reveals Changes in the Metabolic Pathways of Ampicillin- and Gentamicin-Resistant Staphylococcus aureus

Antibiotic resistance is a major global challenge requiring new treatments and a better understanding of the bacterial resistance mechanisms. In this study, we compared ampicillin-resistant (R-AMP) and gentamicin-resistant (R-GEN) Staphylococcus aureus strains with a sensitive strain (ATCC6538) using metabolomics. We identified 109 metabolites; 28 or 31 metabolites in R-AMP or R-GEN differed from those in ATCC6538. Moreover, R-AMP and R-GEN were enriched in five and four pathways, respectively. R-AMP showed significantly up-regulated amino acid metabolism and down-regulated energy metabolism, whereas R-GEN exhibited an overall decrease in metabolism, including carbohydrate, energy, and amino acid metabolism. Furthermore, the activities of the metabolism-related enzymes pyruvate dehydrogenase and TCA cycle dehydrogenases were inhibited in antibiotic-resistant bacteria. Significant decreases in NADH and ATP levels were also observed. In addition, the arginine biosynthesis pathway, which is related to nitric oxide (NO) production, was enriched in both antibiotic-resistant strains. Enhanced NO synthase activity in S. aureus promoted NO production, which further reduced reactive oxygen species, mediating the development of bacterial resistance to ampicillin and gentamicin. This study reveals that bacterial resistance affects metabolic profile, and changes in energy metabolism and arginine biosynthesis are important factors leading to drug resistance in S. aureus.

A synthetic antibiotic class with a deeply-optimized design for overcoming bacterial resistance

The lack of new drugs that are effective against antibiotic-resistant bacteria has caused increasing concern in global public health. Based on this study, we report development of a modified antimicrobial drug through structure-based drug design (SBDD) and modular synthesis. The optimal modified compound, F8, was identified, which demonstrated in vitro and in vivo broad-spectrum antibacterial activity against drug-resistant bacteria and effectively mitigated the development of resistance. F8 exhibits significant bactericidal activity against bacteria resistant to antibiotics such as methicillin, polymyxin B, florfenicol (FLO), doxycycline, ampicillin and sulfamethoxazole. In a mouse model of drug-resistant bacteremia, F8 was found to increase survival and significantly reduce bacterial load in infected mice. Multi-omics analysis (transcriptomics, proteomics, and metabolomics) have indicated that ornithine carbamoyl transferase (arcB) is a antimicrobial target of F8. Further molecular docking, Isothermal Titration Calorimetry (ITC), and Differential Scanning Fluorimetry (DSF) studies verified arcB as a effective target for F8. Finally, mechanistic studies suggest that F8 competitively binds to arcB, disrupting the bacterial cell membrane and inducing a certain degree of oxidative damage. Here, we report F8 as a promising candidate drug for the development of antibiotic formulations to combat antibiotic-resistant bacteria-associated infections.

Zinc priming enhances Capsicum annuum immunity against infection by Botrytis cinerea- From the whole plant to the molecular level

Micronutrient manipulation can enhance crop resilience against pathogens, but the mechanisms are mostly unknown. We tested whether priming Capsicum annuum plants with zinc (5 μM Zn) or manganese (3 μM Mn) for six weeks increases their immunity against the generalist necrotroph Botrytis cinerea compared to deficient (0.1 μM Zn, 0.02 μM Mn) and control conditions (1 μM Zn, 0.6 μM Mn). Zinc priming reduced the pathogen biomass and lesion area and preserved CO2 assimilation and stomatal conductance. Zinc mobilization at the infection site, visualized by micro-X-ray fluorescence, was accompanied by increased Zn protein binding obtained by size exclusion HPLC-ICP/MS. A common metabolic response to fungal infection in Zn- and Mn-primed plants was an accumulation of corchorifatty acid F, a signaling compound, and the antifungal compound acetophenone. In vitro tests showed that the binding of Zn2+ increased, while Mn2+ binding decreased acetophenone toxicity against B. cinerea at concentrations far below the toxicity thresholds of both metals in unbound (aquo complex) form. The metal-specific response to fungal infection included the accumulation of phenolics and amino acids (Mn), and the ligand isocitrate (Zn). The results highlight the importance of Zn for pepper immunity through direct involvement in immunity-related proteins and low molecular weight Zn-complexes, while Mn priming was inefficient.

Proteomic analysis of Staphylococcus aureus exposed to bacteriocin XJS01 and its bio-preservative effect on raw pork loins

Antibacterial mechanism of bacteriocins against foodborne S. aureus is still to be explored, particularly in proteomics, and a deep and comprehensive study on application of bacteriocins for preservation of raw pork is required. Here, proteomic mechanism of Lactobacillus salivarius bacteriocin XJS01 against foodborne S. aureus 2612:1606BL1486 (S. aureus_26) and its preservation effect on raw pork loins stored at 4 °C for 12 days was investigated. The results showed that 301 differentially abundant proteins (DAPs) were identified between XJS01-treated and -free groups (control group) using Tandem mass tag (TMT) quantitative proteomics technology, which were primarily involved in amino acids and carbohydrate metabolism, cytolysis, defense response, cell apoptosis, cell killing, adhesion, and oxygen utilization of S. aureus_26. Bacterial secretion system (SRP) and cationic antimicrobial peptide resistance may be key pathways to maintain protein secretion and counteract the deleterious effects on S. aureus_26 caused by XJS01. In addition, XJS01 could significantly improve the preservation of raw pork loins by the evaluation results of sensory and antibacterial activity on the meat surface. Overall, this study showed that XJS01 induced a complex organism response in S. aureus, and it could be potential pork preservative.

Study on Antibacterial Activity and Mechanism of Improved Dian Dao San Against Cutibacterium acnes (C. acnes)

Purpose

The hyperproliferation of C. acnes has long been regarded as a primary etiological factor in the development of acne vulgaris (AV). Antibiotics targeting C. acnes have been the mainstay in AV treatment. Meanwhile, C. acnes has developed resistance to numerous antibiotics. IDDS, as traditional Chinese medicine, exhibits potent antibacterial activity against C. acnes. However, the mechanism of IDDS against C. acnes remains unclear.

Methods

In this study, we conducted a systematic investigation in vitro to determine the minimal bactericidal concentration (MBC) and time-kill curves. The MBC and time-kill curves were assessed by quantifying Colony Forming Units countsIn order to establish an in vivo rat ear model of acne, a single intradermal injection of 100μL C. acnes suspension was administered, and oleic acid was applied to the right ear pinna for a duration of 14 days. The intervention involved the utilization of IDDS medications. Additionally, the levels of inflammatory mediators tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) were assessed using respective ELISA kits, while Hematoxylin and eosin (HE) staining was employed to visualize the rat ear model. The antimicrobial mechanism was investigated through the analysis of mRNA levels using real-time, quantitative PCR. ELISA analysis was performed according to the protocols outlined for energy metabolism and antioxidant system.

Results

Our research has demonstrated that IDDS possesses antibacterial activity against C. acnes both in vitro and in vivo. The mechanisms underlying these effects involve energy metabolism and antioxidant systems.

Conclusion

The data has provided further insights into the mechanism of IDDS against C. acnes, which establishes a robust foundation for the clinical application of IDDS.

Antibacterial Mechanism of Patrinia scabiosaefolia Against Methicillin Resistant Staphylococcus epidermidis

Purpose

Staphylococcus epidermidis has become one of the most common causes of septicemia. Meanwhile, S. epidermidis has acquired resistance to many antibiotics. Among these, methicillin-resistant S. epidermidis (MRSE) were frequently isolated. Similar to methicillin resistant Staphylococcus aureus (MRSA), they also exhibited multi-resistance, which presented a danger to human health. Patrinia scabiosaefolia as traditional Chinese medicine had strong antibacterial activity against MRSE. However, the mechanism of P. scabiosaefolia against MRSE is not clear.

Methods

Here, the morphology of cell wall and cell membrane, production of β-lactamase and PBP2, energy metabolism, antioxidant system were systematically studied.

Results

The data showed that P. scabiosaefolia damaged the cell wall and membrane. In addition, β-lactamase, energy metabolism and antioxidant system were involved in mechanisms of P. scabiosaefolia against MRSE.

Conclusion

These observations provided new understanding of P. scabiosaefolia against MRSE to control MRSE infections.