Glycosides derived from Hemidesmus indicus R. Br. root inhibit adherence of Salmonella typhimurium to host cells: receptor mimicry

For centuries, indigenous plants have been used against enteritis but their molecular targets and mode of action remain obscure. The present study was carried out to elucidate the protective and therapeutic role, if any, of glycosides from Hemidesmus indicus against S. typhimurium-induced pathogenesis. Studies were carried out in a human intestinal cell line (Int 407) and a murine macrophage cell line (P388D1) in order to evaluate its potency in local as well as systemic infections. The inhibitory role of the glycosides present in Hemidesmus indicus root extract (GHI) were tested by pre-coating the cells (both Int 407 and P388D1) with GHI prior to infection, and by neutralizing the wild-type bacteria with GHI before cell infection. In both cases, GHI protected the host cells from the cytotoxic effects of the wild S. typhimurium. This suggests that the biologically significant sugars (hexose, hexosamine, fucose and sialic acid etc) present in GHI might be mimicking host cell receptor saccharides and thereby blocking the bacterial ligands from binding to the host cells. Int 407 cells infected with wild-type bacteria had a diffused adherence pattern after 4 h incubation, but this typical character was not observed in cells infected with GHI-treated bacteria and the cells were normal in appearance at 4 h. After 18 h cells infected with wild-type bacteria were hypertrophoid with a disintegrated membrane and wrapped in a bacterial coat, whereas cells infected with treated bacteria had comparatively less morphological changes and few defective shrunken rods adhered locally. This suggests that the glycosides can change the adherence pattern of S. typhimurium from diffused to local. Treated bacteria had less adherence and invasion capability in Int 407 as well as P388D1 cells. The results show the decreased ability of adherence of GHI-treated S. typhimurium was due to a loss of surface hydrophobicity. A nonspecific binding between S. typhimurium and the glycosides was confirmed using ELISA. In summary, the glycosides of H. indicus root inhibited S. typhimurium induced pathogenesis nonspecifically, by reducing bacterial surface hydrophobicity and perhaps also by mimicking host cell receptors, thereby blocking its attachment to host cell and further pathological effects.     

Inhibition of enteropathogenic Escherichia coli adhesion on host epithelial cells by Holarrhena antidysenterica (L.) WALL.

Bacterial adhesion is the first step in the sequence of events leading to infection. Previous data are available on the effect of Holarrhena antidysenterica on antidiarrhoeal and antibacterial action, but there is little information on the mechanism of action of the various aspects of EPEC‐induced diarrhoea, namely adherence and translocation of the effector molecule to intestinal epithelial cells. The aim of the present study was to investigate the effects of alkaloids of Holarrhena antidysenterica (AHA) on interference in the mechanism of enteropathogenic Escherichia coli (EPEC) adhesion on host epithelial cells (INT 407 and HEp2). To determine the impact of AHA on epithelial cells, cytotoxicity (LDH), adherence, apoptotic and ultrastructural studies were performed. To analyse the effect of AHA on EPEC secreted proteins, especially EspD, INT 407 monolayers were infected with EPEC and AHA‐treated EPEC, followed by immunoblotting, probed with anti EspD antisera. The maximum percentage of LDH leakage was reduced in AHA‐treated EPEC (400 µg/mL) in both cell lines. Reduced bacterial adherence was observed under light microscopy and altered apoptotic changes were visualized using propidium iodide staining in conjunction with fluorescence microscopy, in both cell lines infected with AHA‐treated EPEC and these results were confirmed with transmission electron microscope images. The suppression of type III secretory proteins (TTSPs), EspD (～40 kDa), was detected in INT 407 cells infected with AHA‐treated EPEC. In conclusion, AHA reduces initial bacterial adhesion to intact epithelial cells and it may exert an antiadherence effect against the pathogenesis of EPEC in host epithelial cells. Thus, the investigations provide a rational basis for the treatment of EPEC‐mediated diarrhoea with AHA. Copyright © 2009 John Wiley & Sons, Ltd.     

斑蝥酸钠维生素B6诱导人肝癌HepG2细胞凋亡及周期阻滞

目的: 研究斑蝥酸钠维生素B6（艾易舒）注射液对人肝癌HepG2细胞增殖、细胞周期与凋亡的影响,探讨其分子机制。 方法: 将不同浓度的斑蝥酸钠维生素B6注射液（0,1,5,10 mg·L^-1）作用于人肝癌HepG2细胞12,24,48 h,MTT法检测细胞增殖抑制率,流式细胞学技术检测细胞凋亡率及细胞周期的变化,Western blot检测蛋白激酶B（Akt）,磷酸化蛋白激酶B（pAkt）,B细胞淋巴瘤-2基因相关X蛋白（Bax）,B细胞淋巴瘤-2基因（Bcl-2）及细胞周期依赖性激酶抑制因子p21蛋白表达变化,RT-PCR检测Bax,Bcl-2及p21 mRNA表达变化。 结果: 斑蝥酸钠维生素B6可显著抑制HepG2细胞的增殖,诱导细胞凋亡,具有显著的时间和浓度效应（P<0.05）;同时G₀/G₁期细胞比例显著升高,S期细胞比例显著降低（P<0.05）。Western blot结果显示斑蝥酸钠维生素B6可下调HepG2细胞中pAkt和Bcl-2蛋白的表达,上调Bax和p21蛋白的表达（P<0.05）。RT-PCR结果显示Bax,p21 mRNA的表达水平明显升高,而Bcl-2 mRNA的表达水平下降（P<0.05）。 结论: 斑蝥酸钠维生素B6可抑制人肝癌HepG2细胞的增殖,诱导其凋亡并引发G₀/G₁期阻滞,其机制可能与斑蝥酸钠维生素B6参与调控磷脂酰肌醇-3-激酶/蛋白激酶B（PI3K/Akt）通路有关。     

Antibacterial potentiality of Mesua ferrea Linn. flowers

The antibacterial efficacy of the methanol extract of whole flowers of Mesua ferrea Linn. was studied against various strains of bacteria. It could inhibit a large number of Gram-positive and Gram-negative bacteria at concentration ranges of 100 to 50 microg/ml, or even lower, as against vibrios and Escherichia coli. In in vivo tests, used at concentrations of 100 and 200 microg/g of body weight, it offered significant protection to Swiss strain of albino mice when challenged with 50 MLD of a virulent strain Sulmonella typhimurium ATCC 6539. Mortality in mice due to these two dosages of the extract alone was insignificant. The extract at 200 microg/g body weight dosage, could significantly reduce the viable count of the strain Sulmonella typhimurium ATCC 6539 in liver, spleen and heart blood of the extract treated challenged mice.     

Antienterobacterial activity of Hemidesmus indicus R. Br. root extract

The antienterobacterial activity of the chloroform and methanol extracts of Hemidesmus indicus root was demonstrated using a variety of methods and different enterobacterial strains. Although the constituents were similar in the chloroform extract (CHI) and the fatty substance separated (ME1) from the methanol extract (MHI), ME1 was found to be more effective than CHI as evident from the disc diffusion method. ME1 was found to be more active than MHI, followed by CHI. This may be due to the inefficient diffusion of CHI into the medium. In a modified agar well diffusion and swab method the activity of the extract against different strains was observed in a single plate. The extracts inhibited growth in a dose dependent manner; both MHI and CHI were most effective against S. flexneri, least effective against S. dysenterie and moderately effective against the other strains. The presence of antimicrobial trace elements such as copper and zinc, along with other active constituents may contribute to the antienterobacterial activity of Hemidesmus indicus root.     

人参皂苷抗金葡菌肺感染的作用

目的:观察研究人参皂苷对金葡菌感染的作用及其特点。方法:体外肺AⅡ型上皮细胞及小鼠肺感染为模型,观察金葡菌感染后细胞侵染相关因子、炎性相关因子以及细菌数和死亡率,以及人参皂苷及人参皂苷Rg1的作用。结果:金葡菌感染后,人参皂苷能够明显降低胞内菌含量,降低粘附因子及其整合素的表达,抑制相关炎性因子,人参皂苷Rg1是其主要活性成分。结论:在抗金葡菌急性感染过程中,人参皂苷发挥了对感染细胞和组织的保护作用,而这些作用不完全依赖于机体免疫系统的功能。     

Evaluation of the genotoxicity of extracts of Houttuynia cordata Thunb

The present study was conducted to evaluate the activity of methanol extracts from Houttuynia cordata Thunb. (HC) in a reverse mutation assay in Salmonella typhimurium, and a chromosome aberration assay in the Chinese hamster ovary (CHO) cell line and to evaluate its effect on the occurrence of polychromatic erythrocytes in mice. In the reverse mutation assay using Salmonella typhimurium TA98, TA100, TA1535, and TA1537 and Escherichia coli WP2urvA(-), methanol extracts of HC (5, 2.5, 1.25, 0.62, or 0.312 mg/plate) did not induce reverse mutations in the presence or absence of an S9 metabolic activation mixture. In the chromosome aberration test using CHO cells, methanol extracts (1.25, 2.5 or 5 μg/ml) caused a few incidences of structural and numerical aberrations, in both of absence or presence of an S9 metabolic activation mixture, but in comparison with the positive control group, these incidences were not significantly increased. In the mouse micronucleus test, no significant increases in the occurrence of micronucleated polychromatic erythrocytes were observed in male ICR mice that were orally administered methanol extracts of HC at doses of 2.0, 1.0, or 0.5 g/kg. From these results, we concluded that the methanol extracts of HC did not induce harmful effects on genes in bacteria, a mammalian cell system or in mouse bone marrow cells. Thus, HC's use for health promotion and/or a sick remedy for humans may be safe.     

粉背南蛇藤中新三萜化合物对RKO细胞体外抗癌作用的研究

目的：探讨粉背南蛇藤中新的三萜齐墩果-12-烯-3β，6α-二醇对人结肠癌细胞系RKO细胞的体外增殖抑制作用和诱导凋亡作用。方法：采用MTT法检测齐墩果-12-烯-3β，6α-二醇对体外培养人结肠癌细胞系RKO细胞的增殖抑制作用，通过AO/EB双染色荧光显微镜、HE染色光学显微镜、DNA琼脂糖凝胶电泳、流式细胞仪分析齐墩果-12-烯-3β，6α-二醇对RKO细胞的诱导凋亡作用及对细胞周期的影响。结果：齐墩果-12-烯-3β，6α-二醇对RKO细胞生长抑制作用具有剂量依赖性和时间依赖性，作用48 h时IC₅₀为（12.20±0.79）μg·mL^-1；AO/EB双染色、HE染色可见典型的肿瘤细胞凋亡改变；10 μg·mL^-1的三萜处理RKO细胞48 h即可出现明显的DNA梯带、流式细胞仪可检测到亚二倍体峰，在10~20 μg·mL^-1内具有明显的量-效作用关系;　并可见RKO细胞G₀-G₁期、G₂-M期的细胞明显减少，而S期细胞无变化。结论：粉背南蛇藤中新的三萜齐墩果-12-烯/-3β，6α-二醇能抑制人结肠癌细胞系RKO细胞增殖和诱导凋亡。     

Pterocarpus santalinus: an In Vitro study on its anti-Helicobacter pylori effect

The anti-H. pylori activity of Pterocarpus santalinus (PS), a traditional herb, has been assessed and compared with that of bismuth subcitrate, through in vitro studies employing rat gastric epithelial cell cultures and H. pylori isolates from gastric mucosal biopsy patients. The MIC of PS was found to be 20 microg/mL. H. pylori was co-cultivated with rat gastric epithelial cells in the presence/absence of PS at its MIC. A reduction in the activity of urease, a normal appearance of the epithelial cells on electron microscopic examination, a decrease in lipid peroxidation and lactate dehydrogenase suggests the possible anti-H. pylori activity of PS.     

Antimicrobial study of bark from five tree species.

The antimicrobial activities of chloroform, methanol and aqueous extracts of the bark of Gymnanthes lucida, Gliricidia sepium, Lysiloma divaricata, Lysiloma tergemina and Coccolaba cozumelensis were tested against S. lutea, E. coli, S. epidermidis, L. monocytogenes, S. choleraesuis, S. aureus, P. aeruginosa, B. pumillus, S. typhimurium, P. vulgaris, V. cholerae and C. albicans. It was found that methanol extracts of the two Lysiloma species and G. sepium had antimicrobial effects against S. epidermidis, S. aureus, P. aeruginosa, B. pumillus and V. cholerae at doses of 200 microg. The major inhibitory effect was observed with L. tergemina which showed a bacteriostatic effect on S. epidermidis at doses of 400 microg/mL.     

马兜铃内酰胺-Ⅰ进入人肾小管上皮细胞及细胞内分布和蓄积的观察

目的:观察马兜铃内酰胺-Ⅰ(AL-Ⅰ)能否进入肾小管上皮细胞及其在细胞内的分布、蓄积情况。方法:以体外培养的人类近端肾小管上皮细胞系(HK-2)为研究对象,用不同质量浓度的AL-Ⅰ(5～20μg.mL^-1)处理细胞,采用荧光倒置显微镜观察细胞内由AL-Ⅰ产生荧光的有无及其分布,并在洗去含AL-Ⅰ的培养液后继续培养HK-2细胞48h,观察细胞内AL-Ⅰ荧光的持续情况以判断其蓄积性。结果:不同质量浓度的AL-Ⅰ(5～20μg.mL^-1)处理细胞0.5h内,均能在肾小管上皮细胞内观察到蓝绿色的AL-Ⅰ荧光,并且荧光仅分布于细胞浆中,而在细胞核内未观察到。在洗去含AL-Ⅰ培养液后继续培养时AL-Ⅰ的荧光可在细胞内持续存在48h以上,其持续存在部位仍为细胞浆。结论:AL-Ⅰ可以在短时间内迅速进入肾小管上皮细胞,其分布部位在细胞浆,不进入细胞核;AL-Ⅰ在细胞浆内的蓄积可能与其致肾损伤的毒性作用机制有关,即通过进入肾细胞并蓄积于细胞内在肾病过程中持续发挥毒性作用。     

Antibacterial activity and in vitro anti-tumor activity of the extract of the larvae of the housefly (Musca domestica)

One of the significant characteristics of traditional Chinese medicine is the use of insects, other terrestrial arthropods and their products as drugs. In the present work, the extract of housefly (Musca domestica) larvae was studied by an agar well diffusion assay and minimum bactericidal concentration (MBC) determination for detection of antimicrobial activity and by MTT assay method to test its in vitro anti-tumor activity. In our studies, the extract inhibited six tested bacterial pathogens and Escherichia coli Jm109, a gene-modified strain resistant to ampicillin with the MBCs ranging from 200 to 1600 microg/ml, while Gram-positive bacteria were more sensitive than Gram-negative bacteria. The extract showed high in vitro anti-tumor activity against human colon cancer cell line CT26 with the IRs ranging from 62 to 89%. The extract of housefly larvae inoculated with Shigella dysenteriae 51302 exhibited higher antibacterial activity and in vitro anti-tumor activity than that of native larvae, which may indicate the same principle involved in the use of Bombyx mori larvae infected with silk moth fungus Beauveria bassiana and Hepialis larvae infected with Cordiceps fungus in the traditional Chinese medicine. Both extracts did not show any coagulation activity and haemolysis activity against rabbit erythrocytes at 500 and 1000 microg/ml. The results support its use in the traditional Chinese medicine, and warrant the further identification of the active molecule in the housefly larvae.     

Cytotoxic and antioxidant activities of alkylated benzoquinones from Maesa lanceolata

The natural and semi-synthetic analogs of substituted 1,4-benzoquinones were evaluated for in vitro cytotoxic and antioxidant activities. Maesanin, dihydromaesanin, maesanin dimethyl ether and isomeric mixtures of 3-[(Z)-10'-pentadecenyl]-benzoquinone derivatives exhibited cytotoxic activity against HL-60 cell line (IC50 values 4.5, 2.2, 0.43 and 2.8 microg/mL, respectively), while it was found to be inactive against ROS (Reactive Oxygen Species) generation in HL-60. In contrast, the isomeric acylated benzoquinones with shorter alkyl substituents, namely, 2-acetoxy-5-hydoxy-6-methyl-3-tridecyl-1,4-benzoquinone and 2-hydoxy-5-acetoxy-6-methyl-3-tridecyl-1,4-benzoquinone showed most prominent antioxidant and antiproliferative effect on HL-60 (IC50 values 6.2 and 2.2 microg/mL, respectively), as well as cytotoxicities against SK-MEL, KB, BT-549 and SK-OV-3 carcinomas (IC50 values <1.1-4.2 microg/mL). All benzoquinones were found to be inactive against cell aggregation and cell adhesion assays, thus showing no effect on immune responses and inflammation.     

Screening of some Tanzanian medicinal plants from Bunda district for antibacterial, antifungal and antiviral activities

Extracts from 50 plant parts obtained from 39 different plants belonging to 22 families used to treat infectious diseases in Bunda district, Tanzania, were screened against twelve microorganisms, including the bacteria Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Salmonella typhimurium, the fungi Aspergillus niger, Candida albicans, and the viruses Herpes Simplex Virus type 1, Vesicular Stomatitis Virus T2, Coxsackie B2 and Semliki Forest A7. The highest activity was obtained for the n-hexane extract of Elaeodendron schlechteranum root bark against the Gram-positive bacteria Bacillus cereus (MIC 0.97 microg/ml and MBC 1.95 microg/ml) and Staphylococcus aureus (MIC 3.90 microg/ml and MBC 31.25 microg/ml). Gram-negative bacteria were less sensitive. Only Balanites aegyptiaca stem bark exhibited a high antifungal activity against Candida albicans (MIC 125 microg/ml and MFC 250 microg/ml). Extracts from four plants; Lannea schweinfurthii, Combretum adenogonium, Ficus sycomorus and Terminalia mollis showed strong antiviral activity with RF values of 10(3) and 10(4) against Herpes Simplex Virus type 1 at various concentrations. Our results support, at least in part, the use of most plants as claimed by traditional healers/informants especially against the Gram-positive bacteria Bacillus cereus and Staphylococcus aureus.     

庆大霉素毫微球的体内抗菌活性研究

 目的：观察庆大霉素与聚氰基丙烯酸正丁酯毫微球结合以后，其体内抗菌活性(特别是对细胞内感染)是否有所增加。方法：以鼠伤寒沙门杆菌感染的C57BL/6j小鼠为细胞内感染的动物模型，以小鼠存活率和器官组织中的活菌计数为指标，对庆大霉素聚氰基丙烯酸正丁酯毫微球的体内抗菌活性进行评价。结果：从存活率评价其治疗指数提高了10倍。肝、脾、肾中活菌计数最低可降至庆大霉素溶液组的1/426，1/141和1/30。结论：与庆大霉素溶液相比，庆大霉素毫微球明显提高了对伤寒沙门杆菌感染小鼠的治疗效果。     

Antimicrobial, antioxidant, antitumour-promoting and cytotoxic activities of different plant part extracts of Garcinia atroviridis griff. ex T. anders

Crude extracts (methanol) of various parts, viz. the leaves, fruits, roots, stem and trunk bark, of Garcinia atroviridis were screened for antimicrobial, cytotoxic, brine shrimp toxic, antitumour-promoting and antioxidant activities. The crude extracts exhibited predominantly antibacterial activity with the root extract showing the strongest inhibition against the test bacteria at a minimum inhibitory dose (MID) of 15.6 microg/disc. Although all the extracts failed to inhibit the growth of most of the test fungi, significant antifungal activity against Cladosporium herbarum was exhibited by most notably the fruit (MID: 100 microg), and the leaf (MID: 400 microg) extracts. None of the extracts were significantly cytotoxic, and lethal towards brine shrimps. The root, leaf, trunk and stem bark extracts (except for the fruits) showed strong antioxidant activity exceeding that of the standard antioxidant, alpha-tocopherol. Antitumour-promoting activity (>95% inhibition) was shown by the fruit, leaf, stem and trunk bark extracts.     

Cytotoxic effects of plant extracts from the families Fabaceae, Oleaceae, Philadelphaceae, Rosaceae and Staphyleaceae

A human transformed line of HeLa cells was treated with extracts prepared from Gymnocladus dioicus, Holodiscus discolor, Stephanandra tanakae, Ligustrum delavayanum, Ligustrum vulgare and Staphylea pinnata. The study evaluating the influence of the active extracts on HeLa cell division also reveals their acute, delayed and combined effect. A 35% degradation of HeLa cells was found after 72 h treatment with 62.5 microg/mL of the extract isolated from Stephanandra tanakae. A 100% lysis of HeLa cells was observed after 72 h treatment with a 125 microg/mL concentration of the extract prepared from Gymnocladus dioicus. The extracts from Ligustrum devayanum and Ligustrum vulgare were specifically effective only with HeLa cells. On the other hand, the extract prepared from Gymnocladus dioicus was effective on the bacteria and on the HeLa cells.     

Antimicrobial and antitumor activities of mycosporulone.

The conditions for optimal production of mycosporulone (1) are given. Its cytotoxic, antimicrobial, and antitumor activities are described. The biological activities of 1 were compared with those of known antibacterial, antifungal, and antitumor agents. The compound was particularly active against Pseudomonas aeruginosa and Staphylococcus aureus (resistant to penicillin). Compound 1 was not toxic to normal human cells (MRC(5)), although it exhibited cytotoxic activity against the human tumor cell lines MDA-MB 231 and PC(3) and the murine L-1210 leukemia cell line.     

Isoterchebulin and 4,6-O-isoterchebuloyl-D-glucose, novel hydrolyzable tannins from Terminalia macroptera

Two new hydrolyzable tannins, isoterchebulin (1) and 4,6-O-isoterchebuloyl-D-glucose (2), together with six known tannins, 3-8, were isolated from the bark of Terminalia macroptera. Their structures were elucidated by extensive 1D and 2D NMR studies, MS, and chemical transformations. Biological activities of all compounds were evaluated against the snail Biomphalaria glabrata, the bacteria Bacillus subtilis and Pseudomonas fluorescens, the nematode Caenorhabditis elegans, and four cancer cell lines (Hep G2, MCF-7/S, MDA-MB-231, and 5637 cells). All compounds except 3 showed antimicrobial activities against B. subtilis (MIC 8-64 microg/mL), whereas only 1 was active against C. elegans (100 microg/mL) and B. glabrata(LC(100) = 60 microg/mL). 3 and 8 were toxic against 5637 cells with LC(50) = 84.66 and 41.40 microM, respectively.     

滨蒿总黄酮对H1N1流感病毒感染的A549细胞先天免疫信号通路的影响＊

目的 探讨滨蒿总黄酮（Total flavonoids from Artemisia scoparia Waldst. et Kit.，ASTF）对抗流感病毒作用及H1N1流感病毒感染的人肺癌A549细胞先天免疫反应过程中起调控作用。方法 定量检测H1N1流感病毒致犬肾上皮MDCK细胞病变（Cytopathic effect， CPE）作用；用TRIzol提取总RNA，RT-qPCR检测ASTF对流感病毒相关信号通路的抗病毒效果，并用流式微球技术（Cytometric bead array， CBA）和ELISA检测ASTF对H1N1流感病毒感染的A549细胞分泌炎性细胞因子的影响。结果 ASTF在体外对H1N1流感病毒有一定抑制作用，可降低H1N1感染的A549细胞先天免疫通路中的RIG-I、AKT、P38、PI3K、STING、PKR和Viperin mRNA表达水平及炎性细胞因子IL-2、IL-6、IL-17A的分泌。结论 ASTF通过抑制胞内先天免疫信号通路RLRs、PI3K/AKT、P38 MAPK发挥免疫调节和抗炎作用，从而达到抗流感的效果。