Antimicrobial Effect Of Resveratrol And The Mechanism Research

Objective: RES was initially discovered as phytoalexin produced by Vitis.A variety of plants can produce RES when challenged by microbial attack.Invasion of grapevines by fungi induces the production of resveratrol to ward off the potentially damaging microbes. Recently, resveratrol has also been shown to have antiviral properties,especially against the gram-positive bacteria and the Dermatophytes.Due to there are only parum research research about antimicrobial effect and the mechanism is not identified, we evaluate the antimicrobial activity of RES in vitro aim to make futher approach to antibacterial activity and mechanism. This may give base to promising clinical application.1 Antibacterial Activity of Resveratrol and Mechanism ResearchMethods: Using the broth microdilution protocol of the Clinical and Laboratory Standards Institute(CLSI) M7-A5, to obtain Minimal inhibitory concentrations of RES on various bacterials.Electron microscope is used to observe the effect of RES on ultrastructure.The electron microscope sample preparation adopt drug-contained plate streak.The final drug concentration is 0.128 mg/ml. Electron microscope sample is ATCC29213,inoculation for 24h at 35℃.The preparation of samples accord to convention.We add the bacteria to a series concentration of RES solution to keep the LSCM sample.The final concentration is 0.032,0.64,0.128 mg/ml.Results: The MIC₅₀ and MIC₉₀ of RES to MSSA are 0.256 and 0.512 mg/ml respectively.The MIC₅₀ and MIC₉₀ of RES to MRSA are 0.256 and 0.512 mg/ml respectively.The MIC₅₀ and MIC₉₀ of RES to CONS are all 0.256 mg/ml.Under the highest concentration-1.024 mg/ml,there is no obvious inhibitory action on E coli and P.aeruginosa. Observing through scanning electron microscope(SEM),we can clearly see that the normal staphylococcus appearance regulated,the size basicly conformity, cellular structure is normal.After affect by 0.128 mg/ml RES the staphylococcus is irregular, the size is unequal,cellwall reductus and with a few echin- scabrosity formed.Transmission electron microscope (TEM) ultrathin section shows that cellular structure is Integrity and clear, cellwall borderline is regularity ,envelope,cellwall,plasma membrane,chromatosome are all seen clearly. After affect by 0.128 mg/ml RES the layer of cellwall is indistinct, the structure of cell organ is blurred, most cytoplasmic inclusion disappeared, generous vacuole emerged. The results of LSCM show that after affect by RES the area and mean indensity are increased contrast with the control group.But as the RES density increasing,it shows a descended tendency.Experimental result indicate that RES has a good antibacterial activity on staphylococci. Electron microscope picture confirm the effective katogene.The LSCM results indicate that RES influence the synthesis of material interior and interact the normal growth and metabolism of the bacteria.But under such serial concentrations there is no obvious depressant effect on E coli and P. aeruginosa which are Gram negative.2 Antifungal Activity of Resveratrol and Mechanism ResearchMethods: Using the microdilution protocol of the CLSI M38-Pand M27-P, to obtain Minimal inhibitory concentrations of RES on Trichophyton rubrum, Trichophyton gypseum and Candida albicans.Electron microscope is used to observe the effect of RES on Ultrastructure.The electron microscope sample preparation adopt drug-contained plate streak.The final drug concentration is 0.032 mg/ml. Electron microscope sample is Trichophyton rubrum,inoculation for 5⁷days at 27℃.The preparation of samples accord to convention.Results: The MIC₅₀ and MIC₉₀ of RES to T.r are all 0.032 mg/ml.The MIC₅₀ and MIC₉₀ of RES to T.g are 0.032 and 0.064 mg/ml respectively.Under the highest concentration-1.024 mg/ml,,there is no obvious inhibitory action on CA. Observing through SEM,we can clearly see that the normal T.r mycelial growth well, mycelial surface smooth and satiation.After affect by 0.032 mg/ml RES the is irregular, the caryotheca broken, dissolve and even disappear. Vacuolus emerged in the chondriosome. Chondriosome shows the character of pyknosis and marrowly. Experimental result indicate that RES has a good antibacterial activity on Dermatophyte. Electron microscope picture confirm the effective katogene. But under such serial experiment concentrations the effect on CA is not fine.Conclusions:1 RES has a very good Antimicrobial effect on staphylococci and Dermatophyte under fairly low concentrations, especially to Dermatophyte.And we wish to provide foundation for clinical application and new drug research. It may offer a new way to cure infection for clinic.2 Through the experiment we initially conclude that RES interfere cellwall synthesis,meanwhile damage cellular membrane, influence the normal cell cycle and inhibit replication of material in the cell. The effect on Dermatophyte may be throuth destroy cellwall or interfere synthesis of cellwall,then enter interior cause destroy of groundplasm and cell organelle,or is the result of the two synergistic mechanisms.