Effects of Helichrysum italicum extract on growth and enzymatic activity of Staphylococcus aureus

Helichrysum italicum G. Don (Compositae) is a shrub commonly found in dry, sandy and stony areas of Mediterranean regions. This plant is known for its anti-inflammatory, anti-allergic and antimicrobial activity. The aim of this study was to evaluate the effect of the diethyl ether extract on growth of Staphylococcus aureus (ATCC 6538P, MRSA and MSSA isolates) and the influence of subminimum inhibitory concentrations (subMICs) on some enzymes which are considered virulence factors. The results indicate that the H. italicum extract had an inhibitory effect on S. aureus strains reducing both their growth and some of the enzymes such as coagulase, DNAse, thermonuclease and lipase. Helichrysum italicum extract could be a novel antimicrobial agent, less toxic to human skin and tissues, worthy of further studies.     

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.     

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.     

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。     

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。     

野牡丹提取液的抗氧化活性研究

目的 研究野牡丹提取液的抗氧化活性。方法 采用二苯代苦味肼基自由基（DPPH•）和铁离子还原/抗氧化能力（FRAP）测定法,测定其抗氧化活性,并将其与芦丁和维生素C（Vc）的抗氧化能力进行比较研究。结果 野牡丹提取液具有较强的抗氧化能力,对DPPH自由基有较好的清除率,半数清除浓度（IC₅₀）为23 μg/mL;对Fe³⁺也具有较好的还原能力,0.5 mol/L FeSO₄当量对应野牡丹提取液质量浓度为55 μg/mL。结论 野牡丹的抗氧化能力与芦丁相近,低于Vc。野牡丹的抗氧化活性在一定浓度范围内与黄酮的含量有较好的相关性。     

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。     

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.     

Activation and apoptosis of mouse peritoneal macrophages by extracts of Larrea divaricata Cav. (jarilla)

Two aqueous extracts, decoction and infusion from Larrea divaricata Cav. (Zygophyllaceae) were investigated for immunomodulating activity on peritoneal macrophages (MΦ). Both extracts reduced significantly the cell viability assessed with the MTT assay at 1 and 4 mg/ml (decoction) and 0.8–4 mg/ml (infusion). Apoptotic morphology showed that at 1 and 4 mg/ml both infusion and decoction triggered an increment of the apoptosis. Pretreatment of MΦ with decoction increased significantly the phagocytosis of zymosan and Candida albicans. The production of NO was estimated as nitrite using the Griess reagent. A slight but significant increase in NO release was observed after the incubation of both extracts (0.2 mg/ml) with LPS during 48 h. As shown in western blot data MΦ cultured with infusion and LPS exhibited the stronger expression of iNOS compared with untreated cells. Both extracts (0.2 mg/ml) increased the binding of LPS-FITC to cells compared with untreated ones. The addition of Staphylococcus aureus blocked completely the binding of LPS-FITC to cells. L. divaricata stimulated the MΦ activation at 0.2 mg/ml whereas it showed a clear pro-apoptotic activity at higher concentrations. The dual effects of L. divaricata are relevant considering the use of this plant to activate the immune system.     

Studies on the antioxidant activity of essential oil and different solvent extracts of Vitex agnus castus L. fruits from Turkey

This study is designed to examine the chemical composition and antioxidant activity of the essential oil and different solvent extracts of Vitex agnus castus. GC and GC–MS analysis was resulted in the detection of 27 components, representing 94.5% of the oil. Major components of the oil were 1,8-cineole (24.98%), sabinene (13.45%), α-pinene (10.60%), α-terpinyl acetate (6.66%), and (Z)-β-farnesene (5.40%). Antioxidant activities of the samples were determined by three different test systems, DPPH, β-carotene/linoleic acid and reducing power assays. In all systems, water extract exhibited excellent activity potential than those of other extracts (hexane, dichloromethane, ethyl acetate and methanol) and the oil. As expected, amount of total phenolics was very high in this extract (112.46 ± 1.22 μg GAEs/mg extract). Dichloromethane extract has been found to be rich in flavonoids. A positive correlation was observed between the antioxidant activity potential and total phenolic and flavonoid levels of the extracts.     

Antiviral activity of an extract derived from roots of Eleutherococcus senticosus

A liquid extract from Eleutherococcus senticosus roots inhibited the productive replication of human rhinovirus (HRV), respiratory syncytial virus (RSV) and influenza A virus in cell cultures infected with these viruses, all of which belong to the RNA type viruses. Analysis of virus production after treatment of the infected cells using plaque-reduction assays showed a strong antiviral activity of the Eleutherococcus extract. In contrast, no effect was detected using the same protocol for cells infected with the DNA viruses, adenovirus (Adeno 5) or herpes simplex type 1 virus (HSV 1). Pre-treatment of cells did not inhibit either virus adsorption or virus replication. The results of the study demonstrate that the Eleutherococcus extract inhibited the replication of all RNA viruses studied so far. This antiviral activity remained stable under the conditions used for drug preparation and storage.     

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.     

In vitro antioxidant activity and total phenolic content of ethanolic leaf extract of Stevia rebaudiana Bert.

The aim of this study was to assess the in vitro potential of ethanolic leaf extract of Stevia rebaudiana as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 μg/ml) was increased in a dose dependent manner, which was found in the range of 36.93–68.76% as compared to ascorbic acid 64.26–82.58%. The IC₅₀ values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 93.46 and 26.75 μg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of S. rebaudiana was achieved using Folin–Ciocalteau reagent containing 61.50 mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC₅₀ values of 93.46, 132.05 and 81.08 μg/ml, respectively. However, the IC₅₀ values for the standard ascorbic acid were noted to be 26.75, 66.01 and 71.41 μg/ml respectively. The results obtained in this study clearly indicate that S. rebaudiana has a significant potential to use as a natural antioxidant agent.     

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...     

Anti-staphylococcal activity of ent-kaurane-type diterpenoids from Croton tonkinensis

Ent-kaurane-type diterpenpoids 1–11, isolated from the dried leaves of the endemic Vietnamese medicinal plant Croton tonkinensis Gagnep. (Euphorbiaceae), were evaluated for inhibitory activity against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. The most active diterpenoids, 2, 3, and 8, exhibited minimum inhibitory concentrations (MICs) of 32, 500, and 125 g/ml, respectively, against MRSA strains.     

泻白散及其主药体外抗氧化活性研究

目的 建立泻白散和方中3味主药甘草、地骨皮、桑白皮的体外抗氧化活性测定方法,并对31批药材和10批泻白散煎液的抗氧化活性进行测定。方法 采用紫外可见分光光度法检测一定浓度的药材提取液引起DPPH溶液吸光度（A）值降低,考察波长为517 nm,分别探索3味药材抗氧化活性成分的提取条件;并进行不同溶剂的吸收考察、专属性考察、DPPH线性考察、药材提取液线性考察、精密度试验、重复性试验、耐用性考察等方法学验证;以清除DPPH自由基的半抑制浓度（IC₅₀）作为评价指标,对泻白散和方中3味药材的体外抗氧化活性进行考察。结果 地骨皮、甘草、桑白皮和泻白散提取液的IC₅₀均值为0.31、1.24、1.49和0.91 g/L,泻白散提取工艺对方中药物抗氧化活性的保留均值为56%。结论 建立的抗氧化活性测定方法可用于泻白散及方中主药的抗氧化活性测定,为多维度评价中药和中药材质量提供新思路。     

五味子提取物对小鼠银屑病样皮损的抑制作用及机制研究

目的 探讨五味子提取物对小鼠银屑病样皮损的抑制作用及机制。方法 使用咪喹莫特乳剂建立小鼠银屑病背部皮损模型,将小鼠分为对照组、模型组、他克莫司5 mg/kg组以及五味子提取物0.05、0.25 mg/kg组,并于造模后在小鼠背部皮肤涂抹相应药物。取小鼠背部皮肤组织,分析皮损症状,对其进行苏木精–伊红（HE）染色,并观察测定表皮厚度。免疫组织化学测定淋巴细胞表面分子（CD-8）、环氧化酶-2(COX-2)、细胞外调节蛋白激酶（ERK）、磷酸化细胞外调节蛋白激酶（p-ERK）的表达情况。建立3D皮肤模型,使用双氧水造模后,噻唑蓝（MTT）检测五味子提取物抗氧化修复活性、酶联免疫吸附法检测皮肤模型组织中超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的酶活力和炎症因子白细胞介素-6(IL-6)的含量。结果 五味子提取物可以缓解由咪喹莫特乳剂诱导的小鼠银屑病皮肤损伤、红斑、炎症,改善其皮损处组织细胞情况,降低银屑病模型小鼠表皮厚度（P<0.05）;五味子提取物可以下调银屑病模型小鼠皮肤组织中COX-2、ERK、pERK、CD-8的表达（P<0.05、0.01）;3D皮肤模型检测结果显...     

Diospyrone, crassiflorone and plumbagin: three antimycobacterial and antigonorrhoeal naphthoquinones from two Diospyros spp.

The aim of this study was to evaluate the antimycobacterial and antigonorrhoeal activities of three naphthoquinones (diospyrone, crassiflorone and plumbagin) from Diospyros canaliculata and Diospyros crassiflora as well as the crude extracts from these plants. The agar disk diffusion assay, broth microdilution method, microplate Alamar blue assay (MABA) and radiometric respiratory technique using the BACTEC 460 TB system were used. Results of the antimycobacterial assays indicated that the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations ranged from 1.22 μg/mL to 39.06 μg/mL for Mycobacterium smegmatis and all studied Mycobacterium tuberculosis strains for the crude extract from D. crassiflora, diospyrone and crassiflorone. Results of the killing rate experiment revealed that a total inhibition effect on M. tuberculosis H37Rv strain was observed at Day 18 for D. crassiflora and Day 21 for the crude extract from D. canaliculata and diospyrone at 4× MIC as determined by MABA. Results of the antigonorrhoeal assay indicated that diospyrone was able to prevent the growth of all studied strains of Neisseria gonorrhoeae. The overall results of this work provide evidence that the studied plant extracts (diospyrone, crassiflorone and plumbagin) might be potential sources of new antimicrobial drugs against tuberculosis and gonorrhoea.     

益母草与鸡血藤及其配伍的抗氧化活性比较

目的 研究益母草与鸡血藤及其配伍抗氧化的能力,并探讨益母草与鸡血藤及其配伍采用水提和醇提是否会对抗氧化能力产生影响,确定最优配比.方法 分别以95％的乙醇和蒸馏水为溶剂超声提取,按比例量取益母草和鸡血藤,在抗氧化实验中,研究各个配比的提取液的DDPH自由基清除能力及还原螯合Fe的能力.结果 水提和醇提在益母草-鸡血藤(...