Preliminary Study On The Inhibitory Effect And Molecular Mechanism Of Medicinal Plants Formula MZL-1 Against MRSA

The drug resistance of pathogenic microorganisms is a huge challenge for clinical treatment.Multidrug Resistant Microbes(MDR)increase the morbidity and mortality of infected persons.Approximately 700,000 people die from MDR infections worldwide each year.The development of medicinal microorganisms has become a daunting global challenge.Among them,Methicillin-resistant Staphylococcus aureus(MRSA)has strong toxicity and antibiotic resistance,which can spread and infect animals and humans,causing a huge economic burden.MRSA spreads globally at an alarming rate and has become one of the most common pathogens in clinical practice.Therefore,there is an urgent need to develop alternative drugs or new antibiotics to deal with the challenge of multi-drug resistant microorganism infection.Phytomedicines are an important resource for the development of innovative drugs.Phytomedicines containing multiple active ingredients have many advantages,such as relatively small side effects and no drug resistance.There are also more and more studies reporting that phytomedicines have inhibitory effects on multi-drug resistant microorganisms including MRSA.Therefore,phytomedicines may be a new way to solve the infection of multi-drug resistant microorganisms.Our research group has been engaged in antibacterial work of phytomedicines for the past five years,and has accumulated more than 200 antibacterial data of phytomedicines.These preliminary works provided great support for this paper.This thesis takes MRSA as the research object,and based on the research group’s preliminary antibacterial screening research on phytomedicines,a variety of phytomedicines such as Scutellaria baicalensis Georgi,Dryobalanops aromatica Gaertn,Rheum palmatum L.and other Phytomedicines are selected in a reasonable ratio and formulated as MZL-1.Through the antibacterial performance evaluation,it is found that the formula MZL-1 can produce 100% inhibitory effect on MRSA at 2 min.The results show that MZL-1 has a strong inhibitory effect on MRSA.The results of the minimum inhibitory concentration(MIC)of MRSA was 7.5%.At the same time,it was also found that MZL-1 has a strong inhibitory effect on standard strains of Staphylococcus aureus,Candida albicans,Pseudomonas aeruginosa,Escherichia coli,Micrococcus luteus and other microorganisms,and the inhibitory effect of MZL-1 on MRSA is even stronger than that of the standard strain of Staphylococcus aureus.This result indicates that MZL-1 has the advantage of not being affected by antibiotic resistance.The relative conductivity and alkaline phosphatase activity of different concentrations of MZL-1 treated with MRSA bacterial solution were measured.The results showed that compared with the control group,the relative conductivity and alkaline phosphatase activity were higher,and showed a concentration-dependent manner.Showing the characteristics of high expression,it is very likely that MZL-1 quickly caused the rupture of the bacteria,causing a large amount of content to overflow.The results of scanning electron microscopy confirmed the death and rupture of a large number of bacteria from the morphology.Finally,through flow cytometry,it was found that after treatment with MZL-1,the number of live cells decreased greatly,and the apoptotic cells increased,and most of them appeared in the early apoptotic stage,which further confirmed the conductivity,alkaline phosphatase and scanning electron microscopy.As a result,MZL-1 has a rapid and effective inhibitory effect on MRSA.Through transcriptome sequencing,it was found that MZL-1 can significantly reduce the expression of virulence genes after processing the MRSA bacterial solution,and regulate a variety of membrane protein-coding genes including ABC transporter.Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment found that most of the pathways are related to the response of bacteria to foreign factors,bacterial bioproduction,metabolism,and material transport.To study the possible mechanism of the prescription MZL-1 through network pharmacology.The obtained compound target genes and the differential genes of microbial infection were crossed to obtain 29 compounds and 23 target genes.According to the correlation ranking,apigenin,baicalein,wogonin,emodin and other compounds may be the key components of MZL-1 antimicrobial infection.The three genes RXRA,RELA,and CDKN1 A may be the key targets of MZL-1 against microbial infections.We constructed a Protein Protein Interaction network and performed a topological analysis on it.We found that NTRK1,TP53,ESR1,CUL3,APP,RELA,MCM2,FN1,EP300,HSP90AA1 and other targets ranked first,and it is speculated that they may be MZL-1 Important role target.Next,GO enrichment analysis shows that target genes are mainly involved in processes such as cell responses to small molecules,cytokines and transcription factors.KEGG enrichment analysis found that most of the pathways involved are related to inflammatory factor response,cell apoptosis,bacterial,viral infection and immune function.The results show that the apigenin,baicalein,wogonin and emodin contained in MZL-1 regulate most of the targets related to microbial infection and may mediate inflammation,mi RNA transcription regulation,gene silencing,and cell cycle Regulation,apoptosis,immune regulation and other biological processes are used to treat microbial infections.To explore the effect of MZL-1 on skin infections by constructing a mouse MRSA infection model.The results showed that MZL-1 has no obvious toxicity.Although it cannot significantly promote wound healing and skin recovery,the serum inflammatory factors TNF-α and IL-6 were detected by Elisa,and it was found that MZL-1 can significantly down-regulate the expression of inflammatory factors.In summary,this thesis takes MRSA as the research object,combined with a large amount of antibacterial experience of Phytomedicines in this research group,scientifically compatible botanical anti-MRSA formula MZL-1.Then through a series of in vivo and in vitro experiments to explore the antibacterial effect of MZL-1 on a variety of microorganisms including MRSA and its preliminary mechanism.