Aislamiento de Escherichia coli productora de toxina Shiga (STEC) en heces de ganado y detección de factores de virulencia asociados con su patogénesis / Isolation of Shiga toxin-producing Escherichia coli (STEC) in cattle stool and detection of virulence factors associated with its pathogenesis

Resumen Objetivo: Aislar STEC en las heces del ganado bovino en el municipio de Ulloa, Valle del Cauca y detectar factores de virulencia asociados con la patogénesis. Materiales y métodos: Se tomaron 21 muestras provenientes de bovinos, las cuales fueron tomadas directamente del recto del animal mediante hisopos. Las muestras se procesaron hasta obtener colonias puras a las cuales se les evaluó la presencia de los genes stx1, stx2, eae, saa y hlyA mediante PCR y posteriormente, se evaluó el efecto citotóxico de las muestras positivas sobre células Vero (ATCC-CCL-81.4). Resultados: De las 21 muestras de heces de bovinos,12 presentaron bacterias con uno o ambos genes stx. Se obtuvieron 106 aislamientos totales de STEC y se observaron diferencias en cuanto a la presencia y ausencia de los genes de virulencia evaluados en los aislamientos de cada bovino, obteniendo cinco combinaciones de genes. 48 aislamientos presentaron únicamente el gen stx2 y 58 presentaron tanto el gen stx1 como el gen stx2; de los 106 aislamientos, se detectaron 44 con el gen hlyA y 57 con el gen saa. Conclusiones: Todos los sobrenadantes de STEC analizados mostraron actividad citotóxica sobre las células Vero, mientras que en ausencia de STEC las células formaron monocapa después de 48 h de incubación. Este trabajo es el primer reporte en Colombia que aporta información sobre la presencia de STEC en el ganado bovino, la presencia de factores de virulencia y el potencial efecto citotóxico que poseen estas cepas nativas.

Abstract Objective: To isolate STEC in stool samples from cattle in Ulloa, Valle del Cauca, and to detect virulence factors associated with its pathogenesis. Materials and methods: We took 21 samples from cattle, which were taken directly from the rectum of the animal using swabs. The samples were processed until obtaining pure colonies and evaluated for the presence of the stx1, stx2, eae, saa and hlyA genes by PCR. Afterward, the cytotoxic effect of positive samples were evaluated on Vero cells (ATCC-CCL- 81.4). Results: We observed that from the 21 stools samples, 12 presented bacteria with one or both stx genes. A total of 106 isolates of STEC were obtained and differences among each other were observed regarding the presence and absence of the virulence genes, obtaining five combinations of genes. We found that 48 isolates presented only stx2 gene and 58 presented both the stx1 and stx2 gene. Regarding the other virulence genes, the hlyA gene was detected in 44 isolates and the saa gene was detected in 57 isolates. Conclusions: All the STEC supernatants showed cytotoxic activity on Vero cells, while in its absence the cells formed monolayer after 48 h of incubation. This work is the first report in Colombia that provides information about the presence of STEC in stool cattle, virulence genes and its potential cytotoxic effect in native strains.

Ocotea porosa: Anatomy and Histochemistry of Leaves and Stems, Chemical Composition, Cytotoxicity and Insecticidal Activities of Essential Oil

Abstract Ocotea porosa (Nees & Mart.) Barroso, commonly known as "imbuia", "canela-imbuia" or "imbuia-amarela" in Brazil, is a tree of the Southern Atlantic Forest. The present study investigates the anatomy of leaf and stem, volatile oil chemistry, as well as cytotoxicity and insecticidal activities of the essential oil of O. porosa. Species identification was achieved by anatomy features, mainly due to paracytic and anomocytic stomata; non-glandular trichomes; biconvex midrib and petiole with a collateral open arc vascular bundle; presence of a sclerenchymatous layer, starch grains and crystal sand in the stem; and the presence of phenolic compounds in the epidermis, phloem and xylem of the midrib, petiole and stem. The main volatile components of the essential oil were α-pinene (19.71%), β-pinene (13.86%) and bicyclogermacrene (24.62%). Cytotoxicity against human cancer cell (MCF-7), mouse cancer cell (B16F10) and mouse non-tumoral cell (McCoy) was observed as well as insecticidal activity of the essential oil against susceptible 'Ft. Dix' bed bugs (Cimex lectularius L.) by topical application.

In vitro comparison of the cytotoxic effects of statins on U266 myeloma cell line

Background & objectives: Statins are one of the most widely used drugs and have antilipidemic effects as well as antioxidant, anti-inflammatory, anti-angiogenic and anti-tumorigenic effects. It has been shown that the synergistic combinations of statins which can provide better clinical benefit in the treatment of cancer and if administered with other anticancer agents, may be an alternative treatment modality. The aim of this study was to assess the efficacy of administrating statin in multiple myeloma (MM) cell line on cell proliferation. Methods: U266 myeloma cells were cultured in 25 or 75 cm[2] flasks by using cell culture medium mixtures obtained with the supplementation of 10 per cent foetal bovine serum and one per cent of penicillin-streptomycin into RPMI 1640 medium. When the cells reached confluence (reached to the density of 70%), they were reproduced by passaging. Cytotoxicity was evaluated by using the XTT test. Results: Statins (atorvastatin and simvastatin), were administered to the U266 myeloma cell line at 100, 50, 25, 12.5, 6.25 and 3.12 ?M concentrations. Inhibitor concentration 50 (IC50) values calculated for atorvastatin and simvastatin were determined as 94 and 38 ?M, respectively. While 100, 50, 25, 12.5, 6.25 and 3.12 ?M concentrations were used for bortezomib, the IC50value calculated for this agent was 18.2 nM. When six concentrations of bortezomib used in the study were combined with 12.5 ?M inactive concentrations of statins that did not cause inhibition in cell proliferation, both atorvastatin and simvastatin increased the effect of bortezomib at all the concentrations used, and simvastatin showed a stronger efficacy than atorvastatin. Interpretation & conclusions: Our in vitro results indicated that atorvastatin and simvastatin when used along with the conventional treatment in myeloma patients, may improve the effectiveness of the standard therapy and prevent the bortezomib-induced cytotoxic and neurotoxic side effects when used at a low dose. Further studies need to be done in MM patints to confirm these findings.

Antioxidant and cytotoxic properties of protein hydrolysates obtained from enzymatic hydrolysis of Klunzinger's mullet (Liza klunzingeri) muscle

Today, consumers are looking for functional foods that promote health and prevent certain diseases in addition to provide nutritional requirements. This study aimed to evaluate the antioxidant and cytotoxic properties of Liza klunzingeri protein hydrolysates. Fish protein hydrolysates (FPHs) were prepared from L. klunzingeri muscle using enzymatic hydrolysis with papain at enzyme/substrate ratios of 1:25 and 1:50 for 45, 90 and 180 min. The antioxidant activities of the FPHs were investigated through five antioxidant assays. The cytotoxic effects on 4T1 carcinoma cell line were also evaluated. The amino acid composition and molecular weight distribution of the hydrolysate with the highest antioxidant activity were determined by HPLC. All six FPHs exhibited good scavenging activity on ABTS (IC50=0.60-0.12 mg/mL), DPPH (IC50= 3.18-2.08 mg/mL), and hydroxyl (IC50=4.13-2.07 mg/mL) radicals. They also showed moderate Fe+2 chelating capacity (IC50=2.12-12.60 mg/mL) and relatively poor ferric reducing activity (absorbance at 70 nm= 0.01-0.15, 5 mg/mL). In addition, all hydrolysates showed cytotoxic activities against the 4T1 cells (IC50=1.62-2.61 mg/mL). 94.6% of peptide in hydrolysate with the highest antioxidant activity had molecular weight less than 1,000 Da. L. klunzingeri protein hydrolysates show significant antioxidant and anticancer activities in vitro and are suggested to be used in animal studies.

Cytotoxic Effect of Thymus caramanicus Jalas on Human Oral Epidermoid Carcinoma KB Cells

Abstract Identifying new chemotherapeutic agents with fewer side effects is a major concern for scientists today. Thymus caramanicus Jalas (Lamiaceae family) is one of the species of Thymus that grows wild in different regions of Iran. Traditionally, leaves of this plant are used in the treatment of diabetes, arthritis and cancer. Here was investigated the cytotoxic property of Thymus caramanicus essential oil and extract in human oral epidermoid carcinoma KB cells. Cell viability was measured by MTT and neutral red assays. The cells were exposed to different concentrations of essential oil (0.05-1 µL/mL) and extract (25-150 µg/mL) for 24 h. Doxorubicin was used as anticancer control drug. The data showed that the essential oil (IC50=0.44 µL/mL) and extract (IC50=105 µg/mL) induce potent cytotoxic property. Surprisingly, cytotoxic effects of essential oil and extract of this plant on KB cancer cells were greater than those on normal gingival HGF1-PI1 cell line. In addition, Thymus caramanicus could potentiate the effect of doxorubicin in sub-effective concentrations. The results of the present study indicate that essential oils and extracts of Thymus caramanicus have potential anti-proliferative property on KB cells and can be used as pharmaceutical case study for oral cancer treatments.

Resumo A identificação de novos agentes quimioterápicos com menos efeitos colaterais é uma grande preocupação para os cientistas de hoje. Thymus caramanicus Jalas (família Lamiaceae) é uma das espécies de Thymus que cresce selvagem em diferentes regiões do Irã. Tradicionalmente, as folhas desta planta são utilizados no tratamento da diabetes, artrite e câncer. Aqui investigamos a propriedade citotóxica do óleo essencial e extrato de Thymus caramanicus em células da linhagem celular tumoral humana de carcinoma epidermóide de boca (KB). A viabilidade celular foi medida por ensaios MTT e vermelho neutro. As células foram expostas a diferentes concentrações de óleo essencial (0,05-1 μL/mL) e extrato (25-150 μg/mL) durante 24 h. A doxorrubicina foi utilizada como droga de controle anticâncer. Os dados mostraram que o óleo essencial (IC50 = 0,44 μL/mL) e o extrato (IC50 = 105 μg/mL) induzem uma potente propriedade citotóxica. Surpreendentemente, os efeitos citotóxicos de óleo essencial e extrato desta planta sobre células cancerígenas KB foram maiores que sobre a linhagem celular gengival normal HGF1-PI1. Além disso, Thymus caramanicus poderia potencializar o efeito da doxorrubicina em concentrações sub-efetivas. Os resultados do presente estudo indicam que óleos essenciais e extratos de Thymus caramanicus têm potenciais propriedades anti-proliferativas sobre células KB e podem ser usado como estudos de caso farmacêuticos para tratamentos de câncer bucal

Advances in studies on flavonoids regulating autophagy in tumor cell lines / 中草药

Autophagy is an evolutionary conserved method in cell self-degradation and metabolism progress. Generally speaking, autophagy contains the steps of phagophore devouring none-essential or damaged organelles, lysosome-mediated degradation and reusing of contents in autophagosome. Autophagy plays a significant role in cellular biosynthesis, nutritional and metabolic balance, stress responses and cell survival. Regulating autophagy can induce multiple cascade reactions, which could be a kind of promising tumor therapy. Different flavonoids could induce different roles of autophagy, when they act on different tumor cell lines. Flavonoids can induce non-apoptosis or non-typical apoptosis related inhibitory autophagy to suppress tumor cells proliferation directly, and induce apoptosis or other lethal pathways after induction of autophagy to indirectly inhibit tumor cells proliferation. Flavonoids can also suppress protective autophagy to strengthen other lethal pathways, but sometimes induce protective autophagy which would weaken the cytotoxic effect. This paper reviews the advances in studies on flavonoids regulating autophagy in the last 10 years, in order to provide reference for the further study on the regulation of autophagy by traditional Chinese Medicine.

Synergistic cytotoxicity of ampelopsin sodium and carboplatin in human non-small cell lung cancer cell line SPC-A1 by Gcell cycle arrested / 中国结合医学杂志

<p><b>OBJECTIVE</b>To evaluate the cytotoxic effects of ampelopsin sodium (Amp-Na) and carboplatin (CBP) used alone or in combination on human non-small cell lung cancer (NSCLC) cells SPC-A1 in vitro and its related mechanism.</p><p><b>METHODS</b>Cytotoxic effects were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The synergistic effects of the drugs were calculated with coefficient of drug interaction (CDI). Cell cycle was determined by flow cytometry (FCM). The levels of p53, p21, cyclinE, cyclinD1, and phosphorylated cyclin-dependent kinase-2 (p-CDK2) were evaluated by Western blot.</p><p><b>RESULTS</b>Amp-Na (6.25-200 μg/mL) and CBP (3.13-100 μg/mL) alone exhibited prominent cytotoxic activity in a concentration-dependent manner on SPC-A1 cells with 50% inhibitive concentration values of 57.07±14.46 and 34.97±6.30 μg/mL, respectively. Drug combinations were associated with significantly higher cytotoxic effects than each drug alone (P<0.05 or 0.01). The CDI analysis confirmed the synergy of Amp-Na and CBP on inhibiting cancer cell viability across a wide concentration range (CDI <1). FCM and Western blot showed that synergistic cytotoxic effects of Amp-Na and CBP were related to Garrested which mainlym ediated by p 21 through the inhibition of CDK2 activity independent of the p53 tumor suppressor pathway.</p><p><b>CONCLUSIONS</b>Amp-Na exhibits anticancer activities and enhances the antitumor activities of CBP through up-regulation of p21 and inhibition of CDK2 activity in human NSCLC cells SPC-A1. These results suggest that Amp-Na may be applied to enhance the anticancer action of CBP.</p>

Synergistic anti-tumor effects of axitinib and doxorubicin / 药学学报

To study the synergistic anti-tumor effects of doxorubicin and axitinib in combination, and investigate the underlying mechanism, we performed the MTT cytotoxic assay and tumor spheroids inhibition to investigate in vitro using A549 cells. The cell internalization, cell cycle distribution and DNA ladder experiments were performed to study the synergistic mechanisms. A549 xenograft was established in nude mice and adopted to study the in vivo anti-tumor effect of doxorubicin and axitinib. Results showed that combination of doxorubicin and axitinib exerted significantly higher cytotoxicity than each single drug, and induced a synergistic effect on tumor spheroids growth inhibition. The combination achieved the highest tumor growth suppression in vivo in the A549 xenograft. The combination of axitinib and doxorubicin exhibited the best anti-tumor effects both in vitro and in vivo than each single drug.

Chemical constituents from Mylabris phalerata and their cytotoxic activity in vitro / 中国中药杂志

Ten compounds were isolated from Mylabris phalerata by using preparative HPLC and column chromatography over MCI gel. On the basis of physical-chemical properties, NMR and MS data analysis, the compounds were identified as 5'-[(1 R,2 R,3 S,6R)-1-hydroxymethyl-2-methyl-3,6-epoxycyclohexane-1,2-dicarboximide]- ethyl-2'-methyl-2'-butenoate (1),cantharidin (2), cyclo-(L-Pro-L-Ala) (3), cyclo-(R-Pro-R-Leu) (4), cyclo-(S-Pro-R-Leu) (5), cyclo-(D-Pro-L-Tyr) (6), indole-3-aldehyde (7), 3-indoleacetic acid (8), valerolactam (9), and 4-hydroxyphthalid (10).Compound 1 was a new compound, and compounds 2-10 were obtained from this genus for the first time. Compounds 1-9 were subjected to cytotoxic activity on HCT-116, HepG2, BGC-823, NCI-H1650, A2780 cell lines, and only compound 2 showed inhibitory effect on all cancer cell lines.

The Scientific Base of Myrmecodia pendans as Herbal Remedies.

Aims: To find out the scientific base of the traditional plant Myrmecodia pendans as a new natural source for herbal remedies in aspect of its therapeutic compounds and cytotoxic effect on normal cells. Study Design: Experimental laboratory, in vitro study. Place and Duration of Study: Laboratorium Bio Core Faculty of Dentistry Trisakti University, Jakarta, Balai Penelitian Tanaman Rempah dan Obat (BALITRO), Bogor and Pusat Studi Satwa Primata, Bogor, between March to August 2014. Methodology: Several extraction methods of Myrmecodia pendans using maceration technique was done to evaluate their phytochemical contents and cytotoxic effects using (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium (MTT) assay method. Results: The phytochemical test of both ethanol 70% extract and boiling water extraction produce active phenolic compounds, especially those of flavonoids. There is no cytotoxic effect of the ethanol 70% dried extract on fibroblast cells by MTT assay method. One way analysis of variance (ANOVA) test showed significant differences of % inhibition cells growth effect between M. pendans extracts and control group (p=0.00<0.05). Tukey’ high significant difference (HSD) test showed significant differences of % inhibition cells growth effect between each concentrations of 500; 250; 100; 50; 25; 12,5; 6,25; 3,125; 1,56 to 1.000 ppm and also between 1.000 ppm to control (p=0.00<0.05). Conclusion: Myrmecodia pendans can be used as herbal remedies and moreover, the water boiling extraction can be employed as a simple manner for community herbal medicine without any toxic effect on cells.

Cytotoxic effect of proteinaceous postbiotic metabolites produced by Lactobacillus plantarum I-UL4 cultivated in different media composition on MCF-7 breast cancer cell

Aims: Lactobacillus sp. has capability of producing an array of bioactive metabolites that exhibit probiotic effects. Therefore, the objective of this study was to determine the cytotoxicity effect of proteinaceous postbiotic metabolites (PPM) produced by Lactobacillus plantarum I-UL4 cultivated in different media composition on MCF-7 breast cancer cell. Methodology and results: L. plantarum I-UL4 was cultivated in yeast extract and modified de Man, Rogosa and Sharpe broth containing Tween 80 (CRMRS+T80) or without Tween-80 (CRMRS-T80). Human breast adenocarcinoma cell (MCF-7) was employed as cancer cell in this study. Cytotoxicity and antiproliferative effects of PPM were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl Tetrazolium Bromide assay and Trypan Blue Dye Exclusion assay, whereas Acridine Orange/Propidium Iodide staining was employed to determine the cytotoxicity mechanism. PPM produced in CRMRS+T80 exerted cytotoxicity in a time and dose dependent manner that was selective towards MCF-7 cancer cell. Profound cytotoxicity with the lowest IC50 concentration of 10.83 µg was detected at 72 h of incubation, whereas the most potent antiproliferative effect revealed by the lowest viable cell population was observed at 24 h of incubation. PPM cultivated in CRMRS+T80 induced 80.87% of apoptotic MCF-7 cells at 48 h of incubation. Conclusion, significance and impact of study: PPM of L. plantarum I-UL4 cultivated in different media composition induced different levels of MCF-7 cancer cell death. The percentage of apoptotic MCF-7 cells treated with PPM cultivated in CRMRS+T80 increased significantly (p < 0.05) from 24 to 48 h of incubation. The results obtained in this study have revealed the potential of PPM produced by L. plantarum I-UL4 as human health supplement and as anticancer preventive agent. Keywords: Lactobacillus plantarum I-UL4; cytotoxic effect; proteinaceous postbiotic metabolites; media composition; breast cancer

Antimicrobial activity against periodontopathogenic bacteria, antioxidant and cytotoxic effects of various extracts from endemic Thermopsis turcica

Objective: To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan, Vural&Küçüködük against periodontopathogenic bacteria, its antioxidant activity and cytotoxic effect on various cancer cell lines. Methods: In vitro antimicrobial activities of ethanol, methanol, ethyl acetate (EtAc), n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Antioxidant properties of the extracts were evaluated by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and β-carotene bleaching methods. Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent. Additionally, cytotoxic activity of the extracts on androgen-insensitive prostate cancer, androgen-sensitive prostate cancer, chronic myelogenous leukemia and acute promyelocytic leukemia human cancer cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human gingival fibroblast cells were used as a control. Results: Our data showed that EtAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemcomitans (MIC: 1.562 mg/mL, MBC: 3.124 mg/mL) and Porphyromonas gingivalis (MIC: 0.781 mg/mL, MBC: 1.562 mg/mL). In antioxidant assays, EtAc extract exhibited also the highest radical scavenging activity [IC

Antimicrobial activity against periodontopathogenic bacteria, antioxidant and cytotoxic effects of various extracts from endemic Thermopsis turcica

Objective: To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan, Vural &Kü?ük?dük against periodontopathogenic bacteria, its antioxidant activity and cytotoxic effect on various cancer cell lines.Methods: In vitro antimicrobial activities of ethanol, methanol, ethyl acetate (EtAc), n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Antioxidant properties of the extracts were evaluated by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and β-carotene bleaching methods. Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent. Additionally, cytotoxic activity of the extracts on androgen-insensitive prostate cancer, androgen-sensitive prostate cancer, chronic myelogenous leukemia and acute promyelocytic leukemia human cancer cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human gingival fibroblast cells were used as a control.Results:Our data showed that EtAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemcomitans (MIC: 1.562 mg/mL, MBC: 3.124 mg/mL) and Porphyromonas gingivalis (MIC: 0.781 mg/mL, MBC: 1.562 mg/mL). In antioxidant assays, EtAc extract exhibited also the highest radical scavenging activity [IC50=(30.0±0.3) μg/mL] and the highest inhibition [(74.35±0.30)%] against lineloic acide oxidation. The amount of phenolic content of it was also the highest [(162.5±1.2) μg/mg gallic acid]. In cytotoxic assay, only ethanol [IC50=(80.00±1.21) μg/mL] and EtAc extract [IC50=(70.0±0.9) μg/mL] were toxic on acute promyelocytic leukemia cells at 20-100 μg/mL (P<0.05). However, no toxic effect was observed on human gingival fibroblast cells.Conclusions:According to our findings, owing to its antioxidant and cytotoxic potential, EtAc extract might include anticancer agents for acute promyelocytic leukemia.

Dynamic monitoring of the cytotoxic effects of protoberberine alkaloids from Rhizoma Coptidis on HepG2 cells using the xCELLigence system / 中国天然药物

AIM@#To investigate the cytotoxic effects of the six protoberberine alkaloids (PAs) from Rhizoma Coptidis on HepG2 cells.@*METHOD@#A systematic screening was conducted to investigate the dynamic response of HepG2 cells to the PAs using the impedance-based xCELLigence system. Cisplatin was selected as the positive control. The real time, concentration-response curves and the 50% inhibitory concentrations (IC50) were acquired to evaluate the anticancer activity of the PAs.@*RESULTS@#All of the six PAs inhibited cell growth and induce death in HepG2 cells in a time- and concentration-dependent manner. The IC50 values of cisplatin, berberine, columbamine, coptisine, epiberberine, jatrorrhizine, and palmatine were 5.13, 42.33, 226.54, 36.90, 302.72, 383.54, and 456.96 μg·mL(-1), respectively. The results obtained using the xCELLigence system corresponded well with those of the conventional methods.@*CONCLUSION@#The xCELLigence system is a reliable and efficient tool for real-time screening of the cytotoxic effect of compounds in cell-based in vitro assays. Coptisine and berberine, with methylenedioxy group at C2 and C3 on the phenyl ring showed stronger effect.than the other four PAs. However, compared with cisplatin, the six PAs didn't show obvious cytotoxic effect on HepG2 cells. These results provided some useful data for the evaluation of the anticancer compounds, and the clinical application of traditional Chinese medicine.

Antimicrobial activity against periodontopathogenic bacteria, antioxidant and cytotoxic effects of various extracts from endemic Thermopsis turcica

<p><b>OBJECTIVE</b>To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan, Vural & Küçüködük against periodontopathogenic bacteria, its antioxidant activity and cytotoxic effect on various cancer cell lines.</p><p><b>METHODS</b>In vitro antimicrobial activities of ethanol, methanol, ethyl acetate (EtAc), n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria, Aggregatibacter actinomycetemcomitans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion, minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC). Antioxidant properties of the extracts were evaluated by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and β-carotene bleaching methods. Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent. Additionally, cytotoxic activity of the extracts on androgen-insensitive prostate cancer, androgen-sensitive prostate cancer, chronic myelogenous leukemia and acute promyelocytic leukemia human cancer cell lines were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Human gingival fibroblast cells were used as a control.</p><p><b>RESULTS</b>Our data showed that EtAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemcomitans (MIC: 1.562 mg/mL, MBC: 3.124 mg/mL) and Porphyromonas gingivalis (MIC: 0.781 mg/mL, MBC: 1.562 mg/mL). In antioxidant assays, EtAc extract exhibited also the highest radical scavenging activity [IC50=(30.0±0.3) µg/mL] and the highest inhibition [(74.35±0.30)%] against lineloic acide oxidation. The amount of phenolic content of it was also the highest [(162.5±1.2) µg/mg gallic acid]. In cytotoxic assay, only ethanol [IC50=(80.00±1.21) µg/mL] and EtAc extract [IC50=(70.0±0.9) µg/mL] were toxic on acute promyelocytic leukemia cells at 20-100 µg/mL (P<0.05). However, no toxic effect was observed on human gingival fibroblast cells.</p><p><b>CONCLUSIONS</b>According to our findings, owing to its antioxidant and cytotoxic potential, EtAc extract might include anticancer agents for acute promyelocytic leukemia.</p>

Lactobacillus rhamnosus GG Protects Cells from Clostridium difficile Toxins.

Aims: To determine the anti-cytotoxic effects of Lactobacillus rhamnosus GG (LGG) against extracellular and intracellular Clostridium difficile toxins. Study Design: Co-culture system. Place and Duration of Study: Division of Infectious Diseases, Department of Medicine, School of Medicine and Public Health and Department of Pathobiological Sciences, School of Veterinary Medicine, Madison, Wisconsin, between April 2010 and August 2011. Methodology: In this study, we investigated the effects of a probiotic LGG (Culturelle®) against a toxigenic C. difficile strain (ATCC 9689) and a non-toxigenic C. difficile strain (ATCC 700057) in a co-culture system. Co-cultures were prepared with 3 ml of 1:10, 1:100 or 1:1000 dilution of an overnight culture of LGG and 2 ml of 1:100 dilution of either the toxigenic or the non-toxigenic strain. Cytotoxic effects of cell-free culture supernatants (CFS) and cell lysates of the toxigenic strain on Vero cells were evaluated after coculturing. The relative abundance of toxin A (TcdA) and Toxin B (TcdB) genes in 72 h cocultures were determined using real time PCR. Results: In co-cultures with 1:10 or 1:100 dilution of LGG, counts of the toxigenic C. difficile strain were about one log unit lower than control pure cultures after incubation for 48 h. In all co-cultures, counts of the non-toxigenic strain were two log units lower than those of controls. Accordingly, LGG resulted in a significant decrease (p < 0.05) in the relative abundance of TcdA and TcdB in target DNA prepared from co-cultures containing the 1:10 or the 1:100 dilution of the probiotic. Co-culturing the toxigenic strain with the probiotic (1:10 and 1:100) decreased (P < 0.05) the cytotoxic effect of both extracellular and intracellular clostridial toxins resulting in up to 30% increase in cell viability. Conclusion: LGG inhibits the growth of C. difficile in a dose-dependent manner and protects cells from C. difficile induced cytotoxicity.

Green synthesis, antimicrobial and cytotoxic effects of silver nanoparticles using Eucalyptus chapmaniana leaves extract

Objective: To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line.Methods:Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60). Results: UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50 ° and 44.76 °. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner. Conclusions: It has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.

Green synthesis, antimicrobial and cytotoxic effects of silver nanoparticles using Eucalyptus chapmaniana leaves extract

<p><b>OBJECTIVE</b>To synthesize silver nanopaticles from leaves extract of Eucalyptus chapmaniana (E. chapmaniana) and test the antimicrobial of the nanoparticles against different pathogenic bacteria, yeast and its toxicity against human acute promyelocytic leukemia (HL-60) cell line.</p><p><b>METHODS</b>Ten milliliter of leaves extract was mixed with 90 mL of 0.01 mmol/mL or 0.02 mmol/mL aqueous AgNO3 and exposed to sun light for 1 h. A change from yellowish to reddish brown color was observed. Characterization using UV-vis spectrophotometery and X-ray diffraction analysis were performed. Antimicrobial activity against six microorganisms was tested using well diffusion method and cytoxicity test using 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole was obtained on the human leukemia cell line (HL-60).</p><p><b>RESULTS</b>UV-vis spectral analysis showed silver surface plasmon resonance band at 413 nm. X-ray diffraction showed that the particles were crystalline in nature with face centered cubic structure of the bulk silver with broad beaks at 38.50° and 44.76°. The synthesized silver nanoparticles efficiently inhibited various pathogenic organisms and reduced viability of the HL-60 cells in a dose-dependent manner.</p><p><b>CONCLUSIONS</b>It has been demonstrated that the extract of E. chapmaniana leaves are capable of producing silver nanoparticles extracellularly and the Ag nanoparticles are quite stable in solution. Further studies are needed to fully characterize the toxicity and the mechanisms involved with the antimicrobial and anticancer activity of these particles.</p>

The frequency,phenotypes and invtiro cytotoxic effects of icrculating CD 56+T cells in the patients with chornic HCV infection / 中华微生物学和免疫学杂志

Objective To explore the cell frequency , phenotypes and in vitro cytotoxic effects of circulating CD56+T cells in the patients with chronic HCV infection .Methods Peripheral blood mononu-clear cells (PBMCs) were isolated from 33 patients with HCV chronic infection and 21 healthy subjects. Multi-color flow cytometry was used to analyze cell frequency , expressions of activating receptors ( NKG2C, CD16 and NKp46) and inhibitory receptors (NKG2A and CD158a) on CD56+T cells.The functional mark-er for cytotoxic effects (CD107a) on circulating CD56+T cells and their cytokines expression (IFN-γand TNF-α) with or without stimulation of K 562 human Leukemia cell line were also analyzed .Then the correla-tions among the expressing levels of CD 107 a, IFN-γand TNF-αwere investigated .Results The frequency of CD56+T cells in periphery lymphocytes were significantly decreased in the patients with chronic HCV in -fection as compared with that in healthy controls ( P=0.018 ).The expressions of activating receptors (NKG2C, CD16 and NKp46) on CD56+T cells from HCV infected patients were decreased (P=0.015 for NKG2C, P=0.036 for CD16 and P=0.001 for NKp46), while there was no significant change in the ex-pressions of inhibitory receptors (P>0.05 for both CD158a and NKG2A).The concentrations of IFN-γand TNF-αsecreted by CD56+T cells in the patients with chronic HCV infection were significantly decreased with or without K562 stimulation (P0.05). The expressions of CD107a, IFN-γand TNF-αwere closely related under the stimulation of K562(r>0.80, P<0.0001).Conclusion The frequency of CD56+T cells was reduced in patients with chronic HCV infec-tion.Moreover, cytotoxic effects and cytokines production mediated by CD 56+T cells were also significantly impaired, indicating that the dysfunction of circulating CD 56+T cells might be associated with the persist-ence of chronic HCV infection .

Cytogenotoxicity of Cymbopogon citratus (DC) Stapf (lemon grass) aqueous extracts in vegetal test systems

The lemon grass, Cymbopogon citratus (DC) Stapf, is an important species of Poaceae family commonly used in the folk medicine in many countries. The aim of this study was to investigate the cytotoxic and genotoxic effects of aqueous extracts from C. citratus leaves on Lactuca sativa (lettuce) root tip meristem cells by cytogenetic studies that have never been done before for lemon grass extracts. For this, lettuce seeds were treated for 72h with different concentrations of lemon grass aqueous extracts (5; 10; 20 and 30 mg/mL). The percentage of germination, root development and cellular behavior were analyzed, and the results showed that the highest concentration of aqueous extracts reduced the mitotic index, the seed germination and the root development of lettuce. The extracts have also induced chromosome aberrations and cellular death in the roots cells of L. sativa.

O capim-limão, Cymbopogon citratus (DC) Stapf, é uma importante espécie da família Poaceae com uma comum utilização na medicina popular em vários países. O objetivo deste estudo foi investigar os efeitos citotóxicos e genotóxicos do extrato aquoso das folhas de C. citratus em células meristemáticas de Lactuca sativa (alface) por meio de estudos citogenéticos, uma vez que estudos desta natureza não existem para extratos aquosos de capim-limão. Para isso, sementes de alface foram tratadas por 72h com diferentes concentrações de extratos aquosos feitos das folhas de capim-limão (5, 10, 20 e 30 mg/mL). O percentual de germinação, desenvolvimento radicular e o comportamento celular foram avaliados e os resultados mostraram que as concentrações mais elevadas dos extratos aquosos reduziram o índice mitótico, o percentual de germinação das sementes e desenvolvimento radicular da alface. Os extratos também induziram aberrações cromossômicas e morte celular nas células das raízes de L. sativa.