In vitro antimicrobial activity of a chitooligosaccharide mixture against Actinobacillus actinomycetemcomitans and Streptococcus mutans.

The purpose of this study was to evaluate the in vitro antibacterial activity of a chitooligosaccharide mixture (MW 2000–30 000 Da) with a deacetylation degree of 91.5% against two representative oral pathogens, Actinobacillus actinomycetemcomitans and Streptococcus mutans. A 0.1% concentration of the chitooligosaccharides (derived from the exoskeletons of marine crustaceans) was used to estimate antibacterial activity. Approximately 2 log colony forming units (CFU)/ml of A. actinomycetemcomitans were inactivated by 0.1% chitosan after 30 min, while 120 min exposure inactivated about 4.5 log CFU/ml of this organism. In contrast, the level of inactivation against S. mutans was less than 0.5 log CFU/ml after an exposure of up to 120 min. Electron microscopy showed that the exposure of A. actinomycetemcomitans to the chitooligosaccharides resulted in the disruption of cell membranes and that it could be considered for the treatment of periodontal diseases associated with A. actinomycetemcomitans.     

50种中药甲醇提取物对嗜水气单胞菌的体外抑菌及抗生物膜活性的评价

目的 评价50种中药甲醇提取物对嗜水气单胞菌的体外抑菌效果以及抗生物膜生成活性。方法 采取甲醇浸提的方法制备中药甲醇提取物,计算提取率;利用多功能酶标仪检测600nm处的吸光度（A₆₀₀）值测定各提取物（0.1、0.2、0.4、0.8、1.6、3.2mg·mL^-1）作用16h对嗜水气单胞菌的抑菌率;结晶紫染色法结合多功能酶标仪测定各提取物的抗生物膜活性。结果 苏木、白芍、侧柏叶等32种中药甲醇提取物对嗜水气单胞菌抑菌效果明显,其中苏木甲醇提取物的抑菌效果最显著,最大抑菌率达95.56%,起效质量浓度为0.1mg·mL^-1;石菖蒲、大青叶、广藿香等20种中药甲醇提取物明显抑制嗜水气单胞菌生物被膜的生成,其中白芍的最大抑制率达96.78%。结论 夏枯草、野菊花、大青叶、赤芍、石菖蒲、地肤子、连翘、苏木、肉桂、女贞子、白芍、甘草、肉豆蔻、鸡血藤、乌药、莪术、侧柏叶17种中药对嗜水气单胞菌同时具有抑菌和抑制生物膜生长活性。     

灰树花多糖体外抑菌及抗氧化活性研究

目的 研究灰树花多糖的抑菌及抗氧化活性。方法 采用紫外分光光度法,以D-无水葡萄糖为对照品,测定灰树花提取物中多糖含量;采用纸片扩散法,以头孢哌酮为阳性对照,测量不同浓度灰树花多糖提取物金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌的抑菌圈直径;采用DPPH法和T-AOC试剂盒法,以清除率为指标,研究灰树花多糖的抗氧化活性。结果 灰树花提取物中多糖含量为53.49%;灰树花提取物对金黄色葡萄球菌、大肠杆菌、枯草芽孢杆菌均有一定的抑菌作用,抑菌圈直径分别为13,11,10 mm;灰树花多糖浓度为0.05~10 mg·mL^-1时,对DPPH自由基具有一定的清除能力,当浓度高于0.5 mg·mL^-1时,开始显示出总抗氧化能力。结论 灰树花多糖具有一定的抑菌和抗氧化能力。     

Antibacterial and membrane damaging activity of Livistona chinensis fruit extract

Livistona chinensis is used in traditional Chinese medicine as an anticancer agent. Experimental studies have shown the antiproliferative and antiangiogenic properties of extracts of L. chinensis fruits and seeds. In the present study, qualitative phytochemical composition of L. chinensis fruits was investigated. We hypothesized that the presence of high concentration of phenolic compounds with astringent properties may result in bacterial cell death. Hence, antibacterial activity of an aqueous extract of L. chinensis fruits was investigated against Staphylococcus aureus. The antibacterial activity was attributed to DNA, enzyme and protein denaturing properties of the phenolic compounds present in the extract. The extract also resulted in increased membrane permeability. The antibacterial, DNA and enzyme denaturing and membrane damaging activity was limited to an acid-precipitable fraction of the extract and these effects were abrogated in presence of proteins. The membrane damaging activity of phenolic compounds was also observed in leucocytes. In conclusion, this study reported the antibacterial activity of the fruits of L. chinensis due to their high content of phenolic compounds.     

毛冬青中有效成分的分离及其对两种主要口腔致病菌的抑制作用

目的 观察、追踪毛冬青抑制口腔常见致龋菌（变形链球菌和具核梭杆菌）的有效部位和成分。方法 通过系统溶剂萃取、大孔树脂及硅胶柱色谱分离等方法以及质谱和核磁共振等鉴定技术,结合液体二倍稀释法,研究毛冬青不同部位及单体对变形链球菌和具核梭杆菌的最低抑菌浓度（MIC）,1%玉洁纯作为阳性对照药。结果 毛冬青三萜总皂苷和冬青素对两种主要口腔致病菌均具有一定的抑制作用,特别对变形链球菌具有显著地抑制效果。结论 毛冬青三萜总皂苷和冬青素对变形链球菌具有很强的抑制作用,具有开发成为抗龋齿的保健牙膏或药品的潜力。     

The effect of Nepeta cataria extract on adherence and enzyme production of Staphylococcus aureus

Nepeta cataria L., commonly known as catnip, is a perennial herb with a considerable folkloric reputation. A diethyl ether extract of this plant has been shown to have antimicrobial activity against fungi and Gram-positive bacteria. The aim of this work was to study the activity of N. cataria extract on 44 Staphylococcus aureus strains, some resistant to methicillin, and S. aureus 6538P (American Type Culture Collection) by evaluating the effect of subminimum inhibitory concentrations on coagulase, DNAse, thermonuclease and lipase production, and on in-vitro adherence. DNAse, thermonuclease and lipase were inhibited by concentrations equal to 1/2 and 1/4 MIC. A reduction of adherence was also observed.     

不同产地五倍子体外抗菌作用研究

目的 考察五倍子不同产地（河北曲阳、浙江嘉兴、湖南桑植、陕西西乡、云南凤县）的体外抗菌作用。方法 五倍子醇提浸膏用倍半稀释法稀释成不同浓度药液,采用管碟法测定各产地五倍子的最小抑菌浓度（MIC）。结果 河北、浙江、湖南、陕西、云南所产五倍子醇提浸膏对金黄色葡萄球菌的MIC依次为6.25、1.562 5、1.562 5、3.125、0.781 25 mg/L;对大肠杆菌的MIC依次为3.125、12.5、6.25、6.25、3.125 mg/L;对白色念珠菌的MIC依次为6.25、1.562 5、3.125、1.562 5、3.125 mg/L;对绿脓杆菌的MIC依次为12.5、6.25、6.25、6.25、3.125 mg/L。结论 河北、浙江、陕西、云南、湖南所产五倍子均有抑菌作用,其中云南产五倍子醇提物对金黄色葡萄球菌、大肠杆菌、绿脓杆菌抑菌作用最强,陕西、浙江产五倍子醇提物对白色念球菌的抑菌作用强。     

In vitro susceptibility of Burkholderia pseudomallei to antimicrobial peptides

Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to many antibiotics, resulting in high mortality rates of 19% in Australia and even 50% in Thailand. Antimicrobial peptides (AMPs) possess potent broad-spectrum bactericidal activities and are regarded as promising therapeutic alternatives in the fight against resistant microorganisms. Moreover, these peptides may also affect inflammation, immune activation and wound healing. In this study, the in vitro activities of 10 AMPs, including histatin 5 and histatin variants, human cathelicidin peptide LL-37 and lactoferrin peptides, against 24 isolates of B. pseudomallei were investigated. The results showed that the antibacterial activities of the individual peptides depended on peptide dose and bacterial isolate. Among the 10 peptides tested, LL-37 exhibited the most effective killing activity. The smooth type A lipopolysaccharide (LPS) phenotype B. pseudomallei appeared to be more susceptible than those expressing the smooth type B LPS and the rough type LPS. Four isolates of B. pseudomallei shown to be resistant to ceftazidime and trimethoprim/sulfamethoxazole were also highly susceptible to LL-37. These data indicate that LL-37 possesses antimicrobial activity against all isolates independent of the LPS phenotype and is therefore a promising peptide to combat B. pseudomallei infections.     

In vitro andin vivo evaluations of LB10517, a novel parenteral broad-spectrum cephalosporin

Thein vitro activity of LB10517, a new catechol-substituted cephalosporin, was compared with those of E-1077, cefpirome and ceftazidime against 1034 clinical isolates collected in Japan. LB10517 showed a broad-spectrum antibacterial activity against a wide range of gram-positive and gram-negative bacteria including non-glucose fermenting rods,Pseudomonas aeruginosa. Against the methicillin-susceptible strains ofStaphylococcus aureus (MSSA) andStreptococcus pyogenes, the MIC₉₀ values of LB10517 which required to inhibit 90% of the strains were 3.13 μg/ml and 0.1 μ/ml, respectively. It was as active as E-1077 but more active than cefpirome and ceftazidime. Methicillin-resistant strains ofS. aureus (MRSA) andEnterococcus spp. were highly resistant to all the test compounds. LB10517 was highly active against most members of the familyEnterobacteriaceae, 90% of which were inhibited at a concentration of less than 0.78 μg/ml, except forEnterobacter cloacae (1.56 μg/ml) andSerratia marcescens (3.13 μg/ml). Its activity was comparable to those of E-1077 and cefpirome but it was greater than that of ceftazidime. AgainstPseudomonas aeruginosa, LB10517 showed the most potent antibacterial activity among the compounds tested. Ninety percent ofP. aeruginosa isolates were susceptible at the concentration of 0.39 μg/ml. Its activity was 32- to 128-fold higher than those of E-1077, cefpirome and ceftazidime. Against imipenem- or ofloxacinresistantP. aeruginosa, LB10517 with MIC₉₀s of 6.25 μg/ml and 3.13 μg/ml, respectively, showed 16-fold more potent activity than the other test compounds. LB10517 showed a relatively high plasma level and long plasma elimination half-life in rats (t_1/2(β), 52 min) and dogs (t_1/2(β), 103 min).     

基于网络药理学和实验验证探讨大蒜抗幽门螺杆菌感染的作用机制

目的 基于网络药理学和分子对接研究探讨大蒜Allii Sativi Bulbus抗幽门螺杆菌(Hp)感染的活性成分及可能的作用机制,并通过体外抑菌试验验证大蒜素对Hp菌株的抗菌活性。方法 利用HERB数据库获取大蒜的活性成分,并通过PharmMapper、Swiss Target Prediction、BATMAN-TCM数据库获取活性成分靶点并构建"药物-成分-靶点"网络,筛选出主要活性成分。通过GeneCards、OMIM、DRUGBANK和DisGeNET数据库收集与Hp感染相关的靶点,取药物与疾病靶点交集,筛选出潜在靶点。利用STRING数据库获取潜在靶点的互作关系,并在Cytoscape中构建蛋白相互作用(PPI)网络,筛选出核心靶点。在DAVID数据库中进行潜在靶点的基因本体论(GO)生物分析与京都基因与基因组百科全书(KEGG)通路富集分析。通过Autodock进行活性成分与核心靶点的分子对接。用体外抗菌试验检测大蒜素的抗Hp活性。结果 共筛选出36个大蒜活性成分,291个潜在靶点,PPI网络分析得到肿瘤蛋白p53(TP53)、酪氨酸蛋白激酶(SRC)、信号传导和转录激活蛋白3(STAT3)、热休克蛋白90α家族A类成员1(HSP90AA1)、丝裂原激活的蛋白激酶(MAPK3)5个核心靶点。GO分析得到954个生物过程,KEGG分析得到176条通路。分子对接结果显示,大蒜活性成分均与核心靶点有较好的结合能力。体外抑菌试验显示大蒜素对3株Hp菌均有抑菌活性,最小抑菌浓度为2 mg/mL。结论 大蒜中的活性成分可能通过作用于TP53、SRC、STAT3、HSP90AA1、MAPK3 5个核心靶点参与Hp感染相关过程,其机制与磷脂酰肌醇3-激酶(PI3K)-蛋白激酶B(Akt)、叉头框蛋白O(FoxO)、低氧诱导因子-1(HIF-1)等信号通路有关,且大蒜素对Hp菌有抑菌活性。     

Antibacterial effect of parabens against planktonic and biofilm Streptococcus sobrinus

Tooth decay is an infectious disease caused by bacteria immobilized on the tooth surfaces. Eradication of these bacteria, for example Streptococcus sobrinus (S. sobrinus), from the oral cavity is essential in the prevention and treatment of tooth decay. We have tested the antimicrobial effect of several paraben derivatives such as methyl (MP), ethyl (EP), propyl (PP) and butyl (BP) against immobilized and planktonic S. sobrinus. The antibacterial effect was as follows: MP>EP>PP=BP on immobilized bacteria and MP>EP=PP>BP on planktonic bacteria. An antibacterial synergistic effect was found between several combinations of parabens on immobilized and planktonic S. sobrinus. Our results indicate that parabens are potential antibacterial agents against immobilized or planktonic bacteria found in the oral cavity.     

鱼腥草不同溶剂提取物的抗病毒活性研究

目的 研究鱼腥草不同溶剂提取物体外抗手足口病毒（enterovirus type 71,EV71）、单纯疱疹病毒1型（herpes simplex virus type 1,HSV-1）、呼吸道合胞病毒（respiratory syncytial virus,RSV）、柯萨奇病毒B3型（coxsackie virus type B3,CV-B3）、柯萨奇病毒B5型（coxsackie virus type B5,CV-B5）的活性。方法 采用细胞体外培养技术,建立不同病毒感染模型,用鱼腥草不同溶剂提取物进行治疗,通过细胞融合病变观察法以及MTT比色法检测得到治疗指数（therapeutic index,TI）,以此判定其体外抗病毒活性。结果 体外抗病毒试验结果证明,鱼腥草不同溶剂提取物对HSV-1、EV71抗病毒作用较强,对RSV、CV-B3、CV-B5的效果甚微或无明显作用。鱼腥草醇提物中黄酮类成分含量较高,抗病毒活性相对较高;30%,50%,75%乙醇提取物以及水提醇沉处理沉淀物对HSV-1的TI值分别是81.68,67.23,41.91,32.61,均高于阳性对照阿昔洛韦TI值23.43,显示鱼腥草水醇提取物抗HSV-1的活性较强;75%,50%,30%乙醇提取物对EV71的TI值分别是19.58,20.13,18.84,效果较为显著。结论 研究证实鱼腥草提取物对HSV-1、EV71的抗病毒活性较高,可一定程度为临床应用鱼腥草治疗这2种病毒感染引发的疾病提供参考依据。     

Antibacterial, antioxidant and cytotoxic activities of extracts of Conyza canadensis (L.) Cronquist growing in Tunisia

Antibacterial antioxidant and cytotoxic activities of petroleum ether, ethyl acetate and methanol extracts of Conyza Canadensis (L.) Cronquist were investigated. Antibacterial activity was evaluated using the agar diffusion and microwell dilution assays against four strains of bacteria. Antioxidant activity was measured by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the cytotoxic activity was tested against Hep-2 cells (laryngeal carcinoma cell line) using methylene blue assays. Among tested extracts, the methanolic extract exhibited important antibacterial activity. It also showed good antioxidant activity with 50% inhibition concentration (IC₅₀) of 120 μg/ml. Cytotoxicity of extracts was time depend, increasing with exposure time and concentration. At 72 h of incubation, the ethyl acetate and petroleum ether extracts demonstrated effective cytotoxic activity against Hep-2 cells with IC₅₀ values of 45 and 50 μg/ml, respectively.     

蒙药巴特日七味丸不同提取部位体外抗菌活性筛选和急性毒性研究

目的 考察蒙成药巴特日七味丸不同提取部位对临床常见7种致病菌的体外抗菌活性,并对筛选出的有效活性部位进行急性毒性评价。方法 采用微孔板TTC法和微孔板比浊法测定吸光度（OD）值和最低抑菌浓度（minimum inhibitory concentration,MIC）,观察巴特日七味丸不同提取部位的抗菌作用,并初步确定其有效活性部位;以巴特日七味丸水提物为对照,采用小鼠半数致死量（half lethal dose,LD₅₀）和最大耐受量试验对巴特日七味丸有效活性部位进行急性毒性评价。结果 巴特日七味丸6种提取部位,包括石油醚、氯仿、乙酸乙酯、正丁醇、乙酸乙酯-正丁醇和水残余等部位均具有一定的抗菌活性,其中乙酸乙酯-正丁醇部位具有较强的抗菌活性,并对金黄色葡萄球菌和肠炎沙门氏菌的抑菌作用较强,MIC分别为0.04,0.08 mg·mL^-1。巴特日七味丸水提物和有效活性部位均没有出现LD₅₀值;最大耐受量相当于临床成人（体质量70 kg）安全用药剂量的120倍左右,均未出现急性毒性现象。结论 巴特日七味丸不同提取部位均具有抗菌活性,其乙酸乙酯-正丁醇部位活性较强,并且急性毒性较低,其作用机制有待于进一步研究。     

Hepatoprotective activity of Andrographis Paniculata and Swertia Chirayita

Andrographis paniculata (Family: Acanthaceae) and Swertia chirayita (Family: Gentianaceae) are two controversial medicinal plants used as Kiriyattu, having similar therapeutic action and are used as a hepatoprotective and hepatostimulative agent. A. paniculata grows in southern parts of India and S. chirayita in the Himalayan region. The present work concerns on the ability of the extracts of these plants to offer protection against acute hepatotoxicity induced by paracetamol (150 mg/kg) in Swiss albino mice. Oral administration of A. paniculata or S. chirayita extract (100–200 mg/kg) offered a significant dose dependent protection against paracetamol induced hepatotoxicity as assessed in terms of biochemical and histopathological parameters. The paracetamol induced elevated levels of serum marker enzymes such as serum glutamate pyruvate transaminase (GPT), serum glutamate oxaloacetate transaminase (GOT), alkaline phosphatase (ALP), and bilirubin in peripheral blood serum and distorted hepatic tissue architecture along with increased levels of lipid peroxides (LPO) and reduction of superoxide dismutase (SOD), catalase, reduced glutathione (GSH) and glutathione peroxidase (GPx) in liver tissue. Administration of the plant extracts after paracetamol insult restored the levels of these parameters to control (untreated) levels. Thus the present study revealed that the extracts of A. paniculata or S. chirayita offered protection against hepatotoxicity induced by paracetamol.     

植物乳杆菌RG-034对大鼠腹泻型肠易激综合征的治疗作用

目的 研究植物乳杆菌RG-034的体外抑菌效果以及对大鼠腹泻型肠易激综合征的治疗作用。方法 采用活菌计数法测定RG-034菌粉活菌数,利用类“牛津杯法”确定植物乳杆菌RG-034对大肠埃希菌、乙型副伤寒沙门菌、金黄色葡萄球菌的抑菌活性。SD大鼠按体质量随机分为对照组、模型组、蒙脱石散组及植物乳杆菌RG-034胶囊组,每组6只。除对照组外,其余大鼠每日ig5g/kg番泻叶联合隔日禁食,持续5周,制备大鼠腹泻型肠易激综合征模型。自造模第3周开始给药,植物乳杆菌RG-034组大鼠igRG-034胶囊(1×10⁹CFU/粒,15mg),2粒/d;蒙脱石散组大鼠ig0.81g/kg蒙脱石散,1次/d;对照组和模型组大鼠ig等量生理盐水,给药3周。观察大鼠一般状态变化,测定稀便率、稀便级以及腹泻指数,采用16S核糖体RNA测序技术分析大鼠结肠中肠道菌群变化。结果 植物乳杆菌RG-034菌粉活菌数为2.5×10¹¹CFU/g,对不同浓度的大肠埃希菌、乙型副伤寒沙门菌、金黄色葡萄球菌均有一定的抑制作用,抑菌圈直径为15.90～25.06mm。与模型组比较,植...     

中药协同抗真菌药物抗念珠菌的研究进展

侵袭性念珠菌感染已成为备受关注的公共卫生问题,而现行治疗念珠菌感染的药物有限,联合用药是一种实用有效的新药开发策略。从天然植物（尤其是药用植物）中提取的化合物及其衍生物与传统的抗真菌剂联合使用对杀灭念珠菌具有显著的协同作用。归纳了念珠菌对传统抗真菌药物的耐药情况,并总结了中药协同传统抗真菌药物的抑菌活性和抑菌机制,以期为抗念珠菌新型治疗策略的研究提供参考依据。     

N-Nitro-L-arginine protects against ischaemia-induced increases in nitric oxide and hippocampal neuro-degeneration in the gerbil

To assess the effects of the nitric oxide synthase inhibitor N^G-Nitro-L-arginine on behavioural, biochemical and histological changes following global ischaemia, the Mongolian gerbil was used. Ischaemia was induced by bilateral carotid occlusion for 5 min. N^G-Nitro-L-arginine was administered i.p. at either 1 or 10 mg/kg 30 min, 6, 24, and 48 h after surgery. 5 min bilateral carotid occluded animals were hyperactive 24, 48 and 72 h after surgery. N^G-Nitro-L-arginine caused some attenuation in this hyperactivity. The activity of nitric oxide synthase was increased in the cerebellum, brain stem, striatum, cerebral cortex and hippocampus of 5 min bilateral carotoid occluded animals. N^G-Nitro-L-arginine reversed the increase in nitric oxide synthase activity in all brain regions. Extensive neuronal death was observed in the CA₁ layer of the hippocampus in 5 min bilateral carotid occluded animals 96 h after surgery. N^G-Nitro-L-arginine significantly protected against the neuronal death of cells in the CA₁ layer.     

蜡梅不同部位精油化学成分分析及其体外抑菌活性研究

目的 研究蜡梅Chimonanthus praecox（Linn.）Link根、叶、果皮中精油的化学组成及其抑菌活性。方法 采用气相色谱-质谱联用（GC-MS）技术对水蒸气蒸馏法提取的蜡梅根、叶、果皮精油进行成分分析,并分别采用肉汤二倍稀释法和菌丝生长法测试蜡梅不同部位精油对细菌和病原真菌的抑制活性。结果 鉴定了蜡梅根精油中的37种成分、蜡梅叶精油中的48种成分、蜡梅果皮精油中的38种成分,蜡酶不同部位精油中具有相同的化合物15种,分别占各部位精油总量的84.05%,36.83%,64.46%。抑菌实验结果表明蜡梅不同部位精油对受试菌均有不同强度的抑制作用。结论 蜡梅根精油对革兰氏阳性菌和病原真菌具有较强的抑菌活性,抑菌谱较广,且该精油含有多种生物活性成分,具有较高的药用价值及开发前景。     

马桑寄生及马桑子中内酯成分分析方法的研究

生药乙醇提取液经聚酰胺柱净化,在硅胶G薄层上,环己烷—乙酸乙酯(1:1)为展开剂,分离了马桑毒素(A)、羟基马桑毒素(B)、马桑亭(C)及另一未知内酯(D),用香草醛—硫酸的乙醇溶液显色后,薄层光密度法测定。本法显色灵敏、稳定,A,B,C在生药中的回收率分别为96.3±5.1,97.7±4.7和97.4±4.6%。用本法测定了马桑寄生叶、马桑子及其注射液以及马桑叶中所含以上内酯成分。