Study On Anti-Bacterial Effect Of Urena Lobata.On S.Aureus

Objective:To study the anti-bacterial activity of urena lobata L.on S.aureus in vitro and vivo.The effect of urena lobata L.on the growth curve of S.aureus was measured in vitro.The mouse pneumonia model of S.aureus infection was established by nasal cavity instillation.Different doses of urena lobata L.alone or combined with cefazolin sodium or levofloxacin were given during the treatment.The anti-bacterial effects of different dose groups on bacterial pneumonia mouse were tested.This study provides experiment evidence for anti-bacterial effect of urena lobata L.against S.aureus.Methods:The effect of urena lobata L.combined with azithromycin,cefazolin sodium or levofloxacin on the growth curve of S.aureus was measured by microdilution in vitro.The mouse pneumonia model of S.aureus infection was established by nasal cavity instillation.The mouse were divided into 9 groups randomly:blank group(NS 0.02 mL·g-1),model group(NS 0.02 mL·g-1),urena lobata L.high?medium and low dose groups(40 g·kg-1,20 g·kg-1,10 g·kg-1),cefazolin group[0.5 g·(kg×d)-1],urena lobata L.+ cefazolin group[urena lobata L.20 g·kg-1,cefazolin 0.5 g·(kg×d)-1],levofloxacin group[0.09 g·(kg×Xd)-1],urena lobata L.+ levofloxacin group[urena lobata L.20 g·kg-1,levofloxacin 0.09 g·(kg×d)-1].There were 32 mouses in each group.The number of males and females were equal.The mouse of model group and each treatment group were injected subcutaneously with hydrocortisone(25 mg·kg-1)at a.m.and injected intraperitoneal with cyclophosphamide(25 mg·kg-1)at p.m.for 3 days.At 1 hour after the last injection of cyclophosphamide,the bacterial suspension(100?L)was dropped nasally in the mouse under ether anesthesia.The mouse keep upright 20 s after nasal drip to make the bacteria enter the lung tissue.The mouse of blank group was given the same amount of saline solution by nasal drip.Nasal drip was given for 2 days,1 time a day.At 24 hour after nasal drip,each group was given corresponding drug 2 times a day,for 4,9,13 days respectively.12 mouses were executed and taken material the fifth day after model establishment and 10 mouses were done the tenth,fourteenth day after model establishment.The lung tissue homogenate colony count(CFU),histologic examination,WBC,NEU%,NEU and IgG,IgM and IL-6,IL-10 of the mouses were monitored.Results:1.The effect of urena lobata L.on the growth curve of S.aureus:when the concentration of urena lobata L.is 0.5 g·L-1,the growth of S.aureus was inhibited almost completely.When 1/4 MIC urena lobata L.combined with 1/8 MIC azithromycin,1/4 MIC cefazolin sodium or 1/2 MIC levofloxacin,the growth inhibitory effect of S.aureus was better than used alone.2.Anti-bacterial Effect of Urena Lobata L.on S.aureus Pneumonia Mouse:(1)After the infection of S.aureus,the spirit of model group mouses was dispirited,the body activities were difference.The lung tissue homogenate colony count(CFU),WBC,NEU%,NEU and IgG,IgM and IL-6,IL-10 of the mouses were increased significantly.The lung histologic examination showed:at the end of the experiment,the structure of lung tissue in mouses was significantly abnormal,pulmonary perivascular and interstitial edema,hemorrhage and necrosis could be found.The alveolar cavities were infiltrated by inflammatory cells.Colones of bacteria could be found in lung tissue.The results showed that the inflammatory lesions in model group mouses were obviously,the mouse pneumonia model of S.aureus infection was established successfully.(2)After treatment with Urena Lobata L.,the lung tissue homogenate colony count(CFU),WBC,NEU%,NEU and IgG,IgM and IL-6,IL-10 of the mouses was reduced significantly.Urena Lobata L.could reduce the inflammatory exudate and infiltration of inflammatory cells in alveolar cavities.It could promote the recovery of the structure of alveolar to normal.With the prolongation of treatment,the anti-bacterial effect of Urena Lobata L.on S.aureus pneumonia mouse was improved to a certain extent.(3)Compared with cefazolin group,the lung tissue homogenate colony count(CFU),WBC,NEU%,NEU and IgG,IgM and IL-6,IL-10 of the urena lobata L.+ Cefazolin group mouses were reduced significantly.It showed anti-bacterial activity of urena lobata L.combined cefazolin on S.aureus pneumonia mouse has improved.Compared with levofloxacin group,the lung tissue homogenate colony count(CFU)of urena lobata L.+ Levofloxacin group was reduced significantly.It showed anti-bacterial activity of urena lobata L.combined levofloxacin on S.aureus pneumonia mouse has improved.3.The effect of Urena Lobata L.on IL-6,IL-10 in S.aureus pneumonia mouse:(1)After the infection of S.aureus,the IL-6,IL-10 in lung tissue homogenate of model group mouses were increased significantly.(2)After treatment with Urena Lobata L.,the IL-6,IL-10 in lung tissue homogenate was decreased significantly.With the prolongation of treatment,the IL-6,IL-10 was decreased significantly.(3)Compared with cefazolin group,the IL-6,IL-10 of urena lobata L.+cefazolin group were decreased significantly.It showed anti-inflammatory effect of urena lobata L.combined cefazolin on S.aureus pneumonia mouse has improved.Conclusions:1.Urena lobata L.shows a certain degree of growth inhibitory effect on S.aureus in vitro.The growth inhibitory effect of urena lobata L.in combination with azithromycin?cefazolin or levofloxacin both are increased significantly,which shows different degrees of combined inhibitory effect against S.aureus.2.Urena lobata L.shows a certain degree of anti-bacterial effects on S.aureus in vivo,it can help mouses inhibit bacterial inflammation and improve the anti-bacterial effect of the body.The anti-bacterial effects of urena lobata L.in combination with cefazolin or levofloxacin both are increased significantly,which shows different degrees of combined anti-bacterial effect against S.aureus.3.The anti-bacterial effects of urena lobata L.combined with cefazolin may be related to the reducing of inflammatory cytokine IL-6,IL-10.4.Although this study is only a preliminary currently of anti-bacterial activity research of urena lobata L.in vitro and in vivo,it provides new ideas and methods for the follow-up anti-bacterial mechanism and molecular pharmacology research.This study provides the theory basis for the systematic study of anti-bacterial effect of urena lobata L.