| Purpose:The purpose of this study was to evaluate the antibacterial effect of Origanum volatile oil on Candida albicans and its efficacy against simple vulvovaginal candidiasis(VVC),and to study the mechanism of Origanum volatile oil’s anti Candida albicans effect in vitro and in vivo.Methods:1.Analysis of the components of the volatile oil from Origanum vulgare.Using gas chromatography mass spectrometry to analyze the components of the volatile oil from Origanum vulgare,it was found that the main active components were phenolic substances 3-methyl-4-isopropylphenol,o-isopropylbenzene,and terpenes γ-Organic substances such as terpinene;99% of oregano volatile oil.2.Study on the antibacterial effect of oregano volatile oil against Candida albicans ATCC 10231 in vitro.The results showed that the initial screening inhibitory zone diameter of oregano volatile oil against Candida albicans could reach 24 ± 2 mm,and the minimum inhibitory concentration was 1.95 mg/m L.At the same time,the effect of oregano volatile oil on the cell wall of Candida albicans was observed through crystal violet staining,determination of extracellular alkaline phosphatase content,and changes in ultraviolet absorbance values;The effects of oregano volatile oil on the cell membrane and nucleus of Candida albicans were observed by ergosterol content and DAPI staining;The effects of oregano volatile oil on the normal metabolic function of Candida albicans can be observed by measuring the content of extracellular proteins and reactive oxygen species(ROS)in fungi;The effect of oregano volatile oil on Candida albicans can be visually observed by scanning electron microscopy.The effect of oregano volatile oil on Candida albicans biofilm was investigated using XTT reduction colorimetry.It was found that oregano volatile oil can inhibit the early formation of biofilms and mature formation of biofilms,while also effectively inhibiting the formation process of biofilms.Using water hydrocarbon two-phase measurement method and inverted fluorescence electron microscopy,it was observed that Origanum volatile oil can reduce the adhesion and hydrophobicity of Candida albicans cell surface.Using q RT-PCR method,the effect of Origanum volatile oil on the expression of genes related to Candida albicans biofilm formation was further investigated.It was found that Origanum volatile oil can downregulate the expression levels of ALS3,ECE1,ERG11,and HWP1 genes related to adhesion and mycelial growth in Candida albicans,This indicates that oregano volatile oil inhibits the growth of Candida albicans biofilm by reducing adhesion and hyphal transformation.4.Study on the anti candida albicans vaginitis effect of oregano volatile oil in vivo.Using a mouse model of vaginitis,the fungal load,histopathology,inflammatory factors,and ROS content of vaginitis were observed and analyzedDetermination of antioxidant enzyme activity,lipid peroxide malondialdehyde(MDA),and caspase related protein blot analysis.The research results showed that the number of fungi in the Origanum volatile oil treatment group significantly decreased after 7 days,and the level of IL-1 in the tissue after treatment β(Interleukin-1 β,IL-1 β)"It is lower than the model group,and oregano volatile oil can reduce the amount and adhesion of Candida albicans on the surface of vaginal epithelial tissue in mice.".In addition,the content of ROS,glutathione peroxidase(GSH-Px),reduced glutathione(GSH),superoxide dismutase(SOD),and malondialdehyde(MDA)in mouse vaginal tissue homogenate was measured to explore the effect of oregano volatile oil on tissue cell apoptosis.Compared with the model group,apoptosis in the vaginal tissue of mice treated with oregano volatile oil changed,and the structure was more similar to that of the blank group;At the same time,it can be observed that oregano volatile oil can effectively reduce cell apoptosis in mouse vaginal tissue through the related protein imprinting assay represented by DNA repair enzyme(PARP),caspase-7,and caspase-9.Results:Origanum volatile oil has a good antibacterial effect on Candida albicans.In vitro experiments,it can inhibit the growth and development of Candida albicans by affecting the bacterial structure of Candida albicans,normal metabolic function of cells,and inhibiting biofilm growth and adhesion.At the same time,Origanum volatile oil can significantly improve the disease status of vaginal candidiasis in mice,effectively alleviating local inflammatory reactions in the vulva of mice,It reduces the redness,swelling,and depilation of the vulva in mice.It also reduces the amount of Candida albicans in the vaginal mucosa.Conclusion:In summary,oregano volatile oil can effectively inhibit the activity of Candida albicans and its biofilm formation,and improve the symptoms of Candidal vaginitis.The possible main mechanism is to inhibit the formation,aggregation,and adhesion of Candida albicans biofilms by disrupting the normal bacterial structure and metabolic function of Candida albicans,and reduce the number of Candida albicans in the vaginal epithelium of mice,At the same time,it can reduce the apoptosis of normal cells in the host through caspase9-caspase7-PARP pathway,eliminate the colonization of Candida albicans in the vaginal mucosa,and improve local inflammation. |
