<i>In-Vitro</i>Inhibitory Effect of Methanol Extracts of Chinese Herbal Drugs on Supercoiling Activity of Bacterial DNA Gyrase

A large number of Chinese herbal drugs (CHDs) exhibit antibacterial activities both in vivo and in vitro, but until now little is known regarding their inhibitory mechanisms. Bacterial DNA gyrase is a proven target for antibacterial agents. Aim of this study was to investigate the in-vitro inhibitory effect of methanol extracts of CHDs against supercoiling activity of bacterial DNA gyrase. Fifteen CHDs were selected and extracted with methanol, respectively. Inhibitory effect of the extracts on DNA gyrase was tested using gel-based DNA supercoiling assay. Among fifteen CHDs tested, methanol extracts of Lonicerae Japonicae Flos (S2), Taraxaci Herba (S7), Glycyrrhizae Radix et Rhizoma Praeparata cum Melle (S8) demonstrated an obvious inhibitory effect against supercoiling activity of DNA gyrase, and the others were either less active or could not be determined with the present method. Moreover, it was likely that S7 and S8 inhibit gyrase in a concentration-dependent manner. In conclusion, DNA supercoiling assay is a promising method to study the inhibitory activity of CHDs on bacterial DNA gyrase. Some CHDs do have gyrase-inhibitory activity as proposed. Further investigations are needed to elucidate the inhibition mechanism of these CHDs on supercoiling activity of gyrase.

Inhibitory effect of Houttuynia cordata Thunb on LPS-induced retinal microglial activation

AIM: To identify the effect of Houttuynia cordata Thunb(HCT) on lipopolysaccharide(LPS)-induced microglial activation and investigate its possible molecular mechanisms. METHODS: The primary retinal microglial cells were cultured from the retinas of newborn Sprague-Dawley rats and exposed to LPS, and/or HCT with different concentrations. The survival ability of retinal microglia cells was tested by standard MTT method. BrdU cell proliferation assay was used to evaluate the proliferation of retinal microglia. Inflammatory factors in the culture supernatants, including TNF-α, iNOS and IL-1β, were measured using ELISA. Microglia cells’ migration was determined with Transwell migration assay. The total p38-MAPK and phosphorylation of p38-MAPK(p-p38-MAPK) were detected with Western blot.RESULTS: Primary retinal microglia in culture exposed to LPS to induce microglia activation. Pretreatment with HCT significantly inhibited the LPS-induced cell proliferation, but not the cell viability. LPS induced inflammatory reaction in microglia and cell migration. HCT significantly reduced LPS-stimulated release of pro-inflammatory factors and decreased the number of migrating cells substantially in a concentration-dependent manner. Moreover, the protein levels of p-p38 MAPK were identified as the up regulation and co-treatment with HCT obviously inhibited the upregulation of p-p38 MAPK, but had no effect on the levels of total p38-MAPK.CONCLUSION: The data suggest that HCT inhibits LPSinduced retinal microglial activation via suppression of the p-p38-MAPK. HCT may be used for the treatment of ocular diseases characterized by over-activated microglia.

Expression and inhibitory activity analysis of a 25-kD Bowman-Birk protease inhibitor in rice

Rice Bowman-Birk inhibitors (RBBI), with one (8 kD) or two homologous domains (16 kD), were found to be effective trypsin inhibitors in vitro. In this study, we demonstrate that the 25-kD protein corresponding to the three-domain RBBI indeed ex- ists in rice in planta, and that the RBBIs are regulated by development and wounding. We also found by inhibitory activity assay that the 3:13 disulfide bond, but not the 4:5 disulfide bond, suppresses the tryp- sin-inhibitory activity, and the D3 domain of RBBI3-1 has no inhibitory activity against trypsin, chymotryp- sin, paparin or subtilisin. Mutation analyses showed that conversion from Lys to Leu or Tyr in the N-terminal P1 site in D1 domain did not create chy- motrypsin-inhibitory activity, suggesting that the structure of the reactive loop in D1 domain hinder the new inhibitory specificity at P1 site, and the chy- motrypsin-inhibitory activity might need the participa- tion of other structures, e.g. 3:13 disulfide bond.

Growth inhibitory response and ultrastructural modification of oral-associated candidal reference strains (ATCC) by Piper betle L. extract

Candida species have been associated with the emergence of strains resistant to selected antifungal agents. Plant products have been used traditionally as alternative medicine to ease mucosal fungal infections. This study aimed to investigate the effects of Piper betle extract on the growth profile and the ultrastructure of commonly isolated oral candidal cells. The major component of Po betle was identified using liquid chromatography-mass spectrophotometry （LC-MS/MS）. Seven ATCC control strains of Candida species were cultured in yeast peptone dextrose broth under four different growth environments： （i） in the absence of P. betle extract; and in the presence of P. beUeextract at respective concentrations of （ii） 1 mg.mL-1; （iii） 3 mg.mL-1; and （iv） 6 mg.mL- 1 The growth inhibitory responses of the candidal cells were determined based on changes in the specific growth rates （μ）. Scanning electron microscopy （SEM） was used to observe any ultrastructural alterations in the candida colonies. LC-MS/MS was performed to validate the presence of bioactive compounds in the extract. Following treatment, it was observed that the p-values of the treated cells were significantly different than those of the untreated cells （P〈0.05）, indicating the fungistatic properties of the P. beUe extract. The candidal population was also reduced from an average of 13.44× 10^6 to 1.78×10^6 viable cell counts （CFU）.mL-1, SEM examination exhibited physical damage and considerable morphological alterations of the treated cells. The compound profile from LC-MS/MS indicated the presence of hydroxybenzoic acid, chavibetol and hydroxychavicol in P. betle extract. The effects of P. betle on candida cells could potentiate its antifungal activity.

无患子籽油护肤乳液的制备及性能分析

为促进无患子籽油在化妆品中的应用研究,首先以无患子籽油为原料制备纳米乳液,以粒径和Zeta电位为指标,采用单因素实验对乳液制备工艺条件进行了优化,然后在单因素实验的基础上制备无患子籽油护肤乳液,并以橄榄油护肤乳液和商品护肤乳液为对照,对其稳定性、安全性、抗氧化活性、保湿性、酪氨酸酶抑制活性及紫外吸收效果进行了评价。结果表明:无患子籽油纳米乳液的最佳制备工艺条件为复合乳化剂(吐温-60与Span A83体积比3∶1)添加量8%、助乳化剂添加量6%、无患子籽油添加量2%或4%、乳化温度70℃、剪切速度12000 r/min;3种护肤乳液RY-1(无患子籽油添加量2%)、RY-2(无患子籽油添加量4%)、RY-3(橄榄油添加量2%)的稳定性、安全性均较好;RY-1、RY-2、RY-3清除DPPH·的EC_(50)分别为61.5、55.7、58.1μg/mL,清除ABTS+·的EC50分别为58.3、50.1、53.5μg/mL,清除·OH的EC50分别为59.7、30.2、59.9μg/mL,清除O_(2)^(-)·的EC_(50)分别为59.6、41.8、57.3μg/mL,对酪氨酸酶活性抑制的EC_(50)分别为147.5、118.6、140.2μg/mL;在相对湿度43%、81%环境下,4种护肤乳液保湿率大小顺序均为RY-2>商品乳液>RY-3>RY-1;无患子籽油护肤乳液具有一定的紫外吸收能力。综上,RY-2配方优于RY-1和RY-3,无患子籽油护肤乳液安全无刺激性,且具有一定抗氧化活性,有良好的应用前景。

Antimicrobial effect of Malaysian vegetables against enteric bacteria

Objective: To investigate the antibacterial activities of green vegetables(pennywort,mint, garlic, parsley and celery) against four common enteric bacteria [Salmonella enterica(ATCC 25957)(S. enterica), Shigella flexneri(ATCC 12022)(S. flexneri),Escherichia coli(ATCC 43889)(E. coli) and Enterobacter cloacae(ATCC 13047)(E. cloacae)] as an alternative medicine for controlling food borne diarrhea disease and the synergistic effect of green vegetables against those bacteria.Methods: Five common vegetables(pennywort, mint, garlic, parsley and celery) were purchased and extracted. The antimicrobial activities of these extracts were tested against four common enteric bacteria(S. enterica, S. flexneri, E. coli and E. cloacae). Ten different concentrations of the extracts(from 640 to 1.25 mg/m L) were prepared and used for the study. The minimal inhibitory concentration(MIC) was determined by the broth dilution method. The antimicrobial activities were assessed by using both well diffusion and disc diffusion methods.Results: Garlic extract showed excellent inhibitory effects on all enteric bacteria. Other plants(parsley, celery, mint and pennywort) were not effective against enteric bacteria.The MIC of garlic against S. flexneri and E. cloacae was 40 mg/m L. The MIC of S. enterica and E. coli were 20 and 10 mg/m L, respectively. The performance of the well diffusion method was better than that of the disc diffusion method with clear and sharp inhibition zones of tested bacteria against plant extracts.Conclusions: Garlic had excellent antimicrobial effects against enteric bacteria and was recommended to be given to patients with gastroenteritis. The other vegetables(pennywort, mint, parsley and celery) showed no inhibitory effects on enteric bacteria but still can be used for its richness in vitamins and fibers. The performance of the well diffusion method was better than that of the disc diffusion method in detecting the antibacterial effects of green vegetables.

Synergistic Effect between Fucoidan and Antibiotics against Clinic Methicillin-Resistant <i>Staphylococcus aureus</i>

Fucoidan is a sulfated polysaccharide that is primarily extracted from brown seaweeds which has been broadly studied in recent years due to its numerous biological properties, including anticoagulant, antithrombotic, antitumor, and antiviral activities. In this study, fucoidan was evaluated against clinic isolated methicillin-resistant Staphylococcus aureus (MRSA) 1 - 20, either alone or with antibiotics, via broth dilution method and checkerboard and time kill assay. Minimum inhibitory concentrations (MICs)/Minimum bactericidal concentrations (MBCs) values for the fucoidan against all the tested bacteria ranged between 64 - 512/256 - 2048 microg/mL, for ampicillin 32 - 1024/64 - 1024 microg/mL and for oxacillin 8 - 64/16 - 256 microg/mL respectively. Furthermore, the MIC and MBC were reduced to one half-eighth as a result of the combination of the fucoidan with antibiotics. 2 - 6 hours of treatment with 1/2 MIC of fucoidan with 1/2 MIC of antibiotics resulted from an increase of the rate of killing in units of CFU/mL to a greater degree than was observed with alone. These results suggest that fucoidan could be employed as a natural antibacterial agent against multi-drug bacteria.

基于偏最小二乘法分析枇杷叶提取物中α-葡萄糖苷酶抑制剂

为快速筛选枇杷叶(Eriobotrya japonica)提取物中的α-葡萄糖苷酶抑制剂,本研究基于组效分析法探究有效组分与酶抑制活性间的关系,揭示其关键活性组分。通过测定不同产地的枇杷叶提取物对α-葡萄糖苷酶的抑制效果,采用超高效液相色谱-质谱联用(UPLC-MS)对其进行成分分析,运用偏最小二乘回归分析法分析活性,并通过分子对接进行验证。结果表明,10种提取物能有效抑制α-葡萄糖苷酶,IC_(50)值为1.31~2.65μg·mL^(-1),且抑制活性强于阳性对照阿卡波糖(IC_(50)为81.98μg·mL^(-1)),其中产自陕西省汉中市的野生枇杷叶提取物的抑制效果最佳,IC_(50)为1.31μg·mL^(-1),对α-葡萄糖苷酶呈竞争型抑制。10批样品的UPLC-MS特征指纹图谱中有16个共有峰,其中有6个共有峰的回归系数与抑制活性呈正相关,变量重要性较大,贡献度较高。通过与二级质谱、数据库及标准品比对,明确其中4个成分分别为科罗索酸、科罗索酸甲酯、奎宁酸和nerolido-3-α-L-rhamnopyranosyl(1→4)-α-L-rhamnopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→6)]-β-D-glucopyranoside。进一步的分子对接结果表明,上述4种活性成分与α-葡萄糖苷酶对接的结合能小于-6.0 kcal·mol^(-1),其中科罗索酸的结合能最低(-8.9 kcal·mol^(-1)),主要通过氢键作用于酶活性中心。本研究结果为后续应用枇杷叶提取物开发降血糖药物提供了研究思路。

不同类型化感物质抑制蓝藻效益比较及联合抑藻效应评述

世界范围内的蓝藻水华持续威胁着水生生态系统功能和人类健康,化感物质凭借其环境安全和对微藻有特异毒性等特征可以短期抑制蓝藻水华的暴发和生长。文章分别概括了酚类化合物、含氮化合物、脂肪酸/酯类、萜类化合物四类化感物质及其衍生物对蓝藻的杀藻效果、潜在机制及特异作用靶点,并依据高效抑藻化感物质(EC_(50)<10 mg/L)的经济成本进一步预估其实际应用潜能。结果表明,单独胁迫下的各类化感物质具不同抑藻特性:脂肪酸/酯类的性价比最优,能以较少剂量对蓝藻产生极强毒性,对蓝藻多样的作用靶点是其具有极强抑制效果的关键,可在0.015-52.95 mg/L浓度范围内将目标蓝藻抑制50%;酚类化合物总数最多、活性普遍较高,半数效应浓度(EC50)为0.05-162.53 mg/L,可通过抑制光合作用、破坏细胞氧化应激平衡和损害细胞壁/膜结构等多种机制抑制蓝藻生长,但高效杀藻酚类化合物的理论成本差异较大,性价比次于脂肪酸位于第二位;含氮化合物对蓝藻生长存在特异性和均匀高效的杀藻作用, EC50集中于0.3-8.14 mg/L,主要通过破坏蓝藻的光合作用、阻断电子传递和破坏细胞结构(包括超微结构)而对蓝藻造成不可逆转的严重损伤,但成本较高、性价比最低而难以广泛实际应用;萜类化合物杀藻作用弱于其他三个类别的化感物质,主要集中于多途径破坏蓝藻细胞的光合功能,但EC50高达25.3-228 mg/L,实际应用也受限。为减少各种化感物质用量、降低经济成本并实现更高效的杀藻效果,文章总结归纳相同和不同类型化感物质联合作用方式和特点,指出化感物质所产生的联合作用效果取决于混合化感物质的数量、作用靶点、混合比例和混合物含量四个因素。综述还提出抑藻靶点多样且互补的化感物质混合(“多靶点组合”)可产生协同杀藻作用,且在混合物中应增加具有高杀藻活性化感物质的比例(“新木桶效应”协同效应)。同时指出依据植物实际分泌物的种类、含量及比例进行多元混合抑藻更易出现协同杀藻作用,为科学、综合、合理地选择和应用化感物质并优化其配比以控制蓝藻水华提供新见解。

不同浸泡条件对杜仲叶茶活性成分的影响

探讨不同浸泡条件对杜仲叶茶活性成分的影响,分析评价了其抗氧化能力及体外降糖作用。分别考察了浸泡温度、时间、次数对杜仲叶茶中黄酮、多酚、绿原酸、京尼平苷酸溶出量的影响。在此基础上,研究其对DPPH·、OH·清除作用及对葡萄糖苷酶的抑制效果。研究表明,当浸泡温度在90℃以上,时间45 min,首次浸泡时活性成分溶出量最大。杜仲叶茶的抗氧化能力研究表明,其对DPPH·、OH·均有一定的清除作用,IC_(50)分别为0.23192、7.44369 g/L,同时,杜仲叶茶体外降糖研究表明,其对葡萄糖苷酶具有明显的抑制效果,IC_(50)为1.94163 g/L。合适的浸泡条件能够保证杜仲叶茶活性成分溶出量最大,更有利于其功效作用的发挥。

没食子酸对猪胰α-淀粉酶和蛋白酶的抑制作用

以没食子酸为材料,通过考察酶质量浓度、反应体系中底物和酶及没食子酸添加顺序、不同反应时间、不同没食子酸质量浓度对猪胰α-淀粉酶、蛋白酶的活性影响,研究没食子酸对两种酶的抑制作用。结果表明,在底物质量浓度为1g/100mL、体系添加顺序为酶液与抑制剂没食子酸溶液37℃预温5min后加入底物溶液的条件下,没食子酸抑制猪胰α-淀粉酶活性最优条件为:α-淀粉酶质量浓度0.64mg/mL,反应时间15min,没食子酸对α-淀粉酶的最大抑制率为95.52%;在体系添加顺序为酶液与抑制剂没食子酸溶液40℃预温5min后加入底物溶液的条件下,没食子酸抑制猪胰蛋白酶活性的最优条件为:胰蛋白酶质量浓度0.63mg/mL,反应时间30min,没食子酸对胰蛋白酶的最大抑制率为99.24%。没食子酸对两种酶的抑制效果均随没食子酸质量浓度的增大而增强。

螺旋藻藻胆蛋白水解产物对ACE抑制活性的研究

采用胃蛋白酶和胰蛋白酶水解螺旋藻藻胆蛋白制备ACE抑制肽,通过体外实验测定其ACE抑制率,以ACE抑制率为指标确定两种蛋白酶的水解条件。结果表明:胃蛋白酶水解条件为:水解温度37℃,酶与底物比1:50,pH3.0,底物质量分数5%,水解产物的ACE抑制率为82.16%,其IC50值为0.104mg/ml;胰蛋白酶水解条件为:水解温度42℃,酶与底物1:50,pH8.0,底物质量分数6%,水解产物的ACE抑制率为93.54%,其IC50值为0.017mg/ml。此外,胃蛋白酶水解产物再用胰蛋白酶水解,其产物的IC50值为0.087mg/ml。

荇菜(Nymphoides peltatum)对铜绿微囊藻(Microcystis aeruginosa)生长的抑制效应及其机制

构建了荇菜(Nymphoides peltatum)与以铜绿微囊藻为优势种的自然藻体共培养系统,分析系统中各藻种藻细胞密度、藻体叶绿素a含量、荇菜生长指标及水下[光]照度的变化;同时以荇菜种植水配置培养基,在适宜光照条件下培养铜绿微囊藻,分析藻类生长生理指标随时间的变化。结果表明:共培养系统中藻类总藻细胞密度显著下降(P<0.05),其中铜绿微囊藻(Microcystis aeruginosa)藻细胞密度下降最为明显,40 d时比初始藻细胞密度减少了94.68%,而三角四角藻(Tetraedron minimum)数量逐渐增多,成为优势藻种,表明荇菜对铜绿微囊藻生长具有明显抑制作用。共培养系统中荇菜鲜重、水下20 cm深处光衰减率均与藻类叶绿素a含量呈显著负相关(P<0.05),表明藻细胞光合能力的大小与荇菜植株的生长及其产生的遮光作用密切相关。随培养时间延长,添加荇菜种植水的培养基中铜绿微囊藻藻细胞光密度值(D650)下降明显;叶绿素a、藻胆蛋白(包括藻蓝蛋白、别藻蓝蛋白、藻红蛋白)相对含量均有不同程度的下降,培养9 d后4者相对含量分别降至5.27%、15.53%、21.11%和48.48%;藻细胞Ca2+Mg2+-ATP酶活性下降明显,表明荇菜种植水中存在着某种对铜绿微囊藻产生抑制作用的活性物质,通过对铜绿微囊藻光反应系统(PSⅠ和PSⅡ)的作用来阻碍藻细胞光合作用进程,抑制藻类生长,说明除了遮光效应外,分泌抑藻活性物质也是荇菜抑制铜绿微囊藻生长的重要机制。

清胰汤Ⅰ号主要药味对胰蛋白酶活性的抑制作用(体外试验)

目的：研究某些治疗急性胰腺炎中药对胰蛋白酶活性的抑制作用。方法：应用测定胰蛋白酶活性的反应系统测走了某些中药的抑酶作用。结果：所选择的中药，如元胡、大黄及栀子都有抑酶作用且其抑酶作用随应用浓度的增加而增加。此外，活血化瘀中药中桃仁几乎没有抑制作用而赤芍或丹皮的抑制胰蛋白酶作用甚至比根子还强。结论：包括元胡、大黄和振子等的某些中药对胰蛋白酶有不同程度的抑酶作用。

落葵提取液抑制普通烟草花叶病毒病的生理效应研究

研究了落葵提取液对烟草普通花叶病毒病(TMV)的防效,结果表明,不论在烟株接种毒液前或后,用落葵提取液处理烟株的叶片与只接种毒液的相比,叶片MDA含量、O2-.产生速率及膜透性明显降低;抗氧化物酶SOD,CAT和POD前6 d活性增强后下降;Lox和PPO活性始终高于健康或接毒液的烟株(CK);PAL活性是先升高后短时间下降,随后又升高。先用落葵提取液再接种毒液处理的烟株对TMV的抑制作用优于先接种毒液再用落葵提取液处理,落葵对TMV的预防具有积极效果。

香草醛对酪氨酸酶活性的抑制

在25℃,pH=6.8的Na2HPO4-NaH2PO4缓冲体系中,采用酶动力学方法研究了香草醛对酪氨酸酶单酚酶和二酚酶活性的抑制效应.实验结果表明:香草醛对酪氨酸酶单酚酶和二酚酶活性均有抑制作用,其半数抑制浓度(IC50)约分别为2.7和4.1mmol/L;香草醛能明显延长单酚酶的迟滞时间,4 mmol/L香草醛能使迟滞时间由1.1 m in延长至3m in;Lineweaver-Burk图显示香草醛对二酚酶的抑制作用表现为混合性抑制,对游离酶的抑制常数和对酶-底物络合物的抑制常数分别为3.48和15.1mmol/L.

荞麦胰蛋白酶抑制剂的原核表达及纯化

根据文献报道的荞麦胰蛋白酶抑制剂的氨基酸序列及本研究室先前已获得的部分基因序列设计引物,经过RT-PCR扩增,获得荞麦胰蛋白酶抑制剂编码区基因全序列.将该基因克隆到原核表达载体pQE-31中,并转化至大肠杆菌M15,经IPTG诱导表达获得可溶性目的蛋白,其表达量约占菌体总蛋白的25%.该目的蛋白经Ni2+-NTA柱亲和纯化,SDS-PAGE分析显示,在大约9kD处出现明显的目的条带,与预计蛋白分子量大小一致.Western blot鉴定证实,目的蛋白N端带有6个组氨酸标签.活性测定表明,目的蛋白具有专一性的胰蛋白酶抑制剂活性,抑制活性约为77U/mg纯化蛋白.本实验为进一步研究荞麦胰蛋白酶抑制剂结构与功能的关系奠定了基础.

七种常见养殖鱼血清胰酶抑制活性的比较

α2巨球蛋白能结合并抑制蛋白酶的活性,但不抑制该蛋白酶对人工合成的小分子底物的酶活。利用这一特性,选择胰酶的一种有色小分子底物BAPNA,建立BAPNA比色检测法,对7种常见养殖鱼:草鱼、鲫、鲢、胡子鲇、鳙、加州鲈和黄鳝的血清胰酶抑制活性进行了比较,胰酶抑制活性由高到低依次为:草鱼>鲫>黄鳝>鳙>鲢>胡子鲇>加州鲈;α2巨球蛋白活性由高到低依次为:黄鳝>草鱼>胡子鲇>加州鲈>鲢>鳙>鲫;黄鳝和草鱼的α2巨球蛋白活性明显高于其他几种鱼的α2巨球蛋白活性。

金丝桃苷在刺五加各部位中的分布及其对胰脂肪酶活性的抑制作用

采用高效液相色谱法测定了刺五加根、茎干、新枝、茎皮、茎韧皮部、叶、花蕾、果中金丝桃苷的含量,并研究了金丝桃苷体外抑制胰脂肪酶的活性。结果表明:刺五加花蕾中金丝桃苷含量最高,达2.4%,金丝桃苷对胰脂肪酶活性有一定的抑制作用,质量浓度为1 mg/mL时抑制率为24.852%。

氟罗沙星体内外抗菌活性及抗生素后效应研究

目的：对比研究氟罗沙星（ＦＬＲＸ）与其它氟喹诺酮类药物对临床分离致病菌的体内外抗菌活性及抗生素后效应（ＰＡＥ）。方法：应用琼脂平板稀释法测定最低抑菌浓度（ＭＩＣ），微量稀释法测定血清杀菌效价（ＳＢＡ），吸光度法测定ＰＡＥ。结果：ＦＬＲＸ对金葡菌、大肠埃希菌、肺炎克雷伯菌、绿脓假单胞菌均具很强的体内外抗菌活性，与氧氟沙星（ＯＦＬＸ）相似，而强于洛美沙星（ＬＦＬＸ）；ＦＬＲＸ对上述受试菌的峰时ＳＢＡ与ＯＦＬＸ和ＬＦＬＸ相似，但谷时ＳＢＡ多在１∶１以上，高于ＯＦＬＸ和ＬＦＬＸ。ＦＬＲＸ无论对革兰阳性或阴性菌均具较长的ＰＡＥ，呈显著的浓度依赖性，除金葡菌外，对其它受试菌的ＰＡＥ均长于ＯＦＬＸ。结论：ＦＬＲＸ抗菌谱广，体内外抗菌活性强，具有较长时间的ＰＡＥ。