Assessment of Antioxidant and Cytotoxic Activities and Identification of Phenolic Compounds of Centaurea solstitialis and Urospermum picroides from Turkey

HIGHLIGHTS The phenolic composition, antioxidant activity and cytotoxic potential of the extracts of C. solstitialis and U. picroides were investigated. Caffeic acid was found as the most abundant phenolic compound in the extracts. Both species showed promising antioxidant activity towards different assays. The highest cytotoxic potential was observed in the extract of C. solstitialis.

Abstract It is known that some genera of the Asteraceae family are commonly used in Turkish folk medicine. Several studies have investigated the biological effects of different extracts of Centaurea and Urospermum species, but studies involving the phenolic composition of C. solstitialis and U. picroides extracts are very limited. This study aimed to investigate the phenolic composition and antioxidant activity of C. solstitialis and U. picroides and evaluate their possible cytotoxic effect. RP-HPLC analysis was used to elucidate the phenolic profiles of the ethanolic extracts of flowering parts of C. solstitialis and U. picroides.The both ethanolic extracts were assessed for their antioxidant properties using DPPH, FRAP, phosphomolybdenum and metal chelating assays. Furthermore, the effect of the extracts on cell viability was evaluated against MCF-7 and PC-3 cancer cells and HEK293 cell line using the MTT assay. The most abundant phenolic compound in both extracts was determined to be caffeic acid, and the amount of this compound was 24078.03 and 14329.59 µg g-1 in the extracts of C. solstitialis and U. picroides, respectively. The antioxidant activity of the extracts was found similar. Compared with U. picroides extract, C. solstitialis extract had higher potential on the inhibition of cell viability. The IC50 value of C. solstitialis on MCF cells was found as 58.53 µg mL-1. These data suggest that the extracts of C. solstitialis and U. picroides may be considered as novel and alternative natural antioxidant and anticancer sources.

Anatomical aspects, chemical analysis and cytotoxic effect of the essential oil from leaves of Casearia arborea (Salicaceae) / Aspectos anatómicos, análisis químico y efecto citotóxico del aceite esencial de Casearia arborea (Salicaceae)

The genus Casearia (Salicaceae) is found in sub-tropical and tropical regions of the world and comprises about 200 species. In Brazil, there are about 48 species and 12 are registered in the State of Rio de Janeiro; including Casearia arborea (Rich.) Urb. Essential oil was obtained from the fresh leaves by hydrodistillation and analyzed by GC-MS and GC-FID. The cytotoxic effect was determined by WST-1 assay. Chemical analysis of the essential oil revealed a very diversified (n = 37 compounds) volatile fraction composed mainly of non-oxygenated sesquiterpenes (90.2%). These sesquiterpenes included byciclogermacrene (18.7%), germacrene D (12.1%) and α-humulene (11.5%). In addition, the essential oil demonstrated cytotoxic effects against A549 tumor cells in the concentration of 4 µg/mL (EC50) (p < 0.05).

El género Casearia (Salicáceas) se encuentra en las regiones tropicales y sub-tropicales del planeta y comprende alrededor de 200 especies. En Brasil existen 48 especies, 12 de las cuales fueron registradas en el Estado de Río de Janeiro incluyendo Casearia arborea (Rich.) Urb. El aceite esencial fue extraído de hojas frescas por hidrodestilación y analizado por GC-MS y GC-FID. El efecto citotóxico fue determinado por ensayo WST-1. Las cavidades secretorias fueron ocasionalmente encontradas tanto en la lámina foliar como en el pecíolo. El análisis químico del aceite esencial reveló una muy diversa fracción volátil (n = 37 compuestos) formada principalmente por sesquiterpenos no oxigenados (90,2%). Estos sesquiterpenos incluyen biciclogermacreno (18,7%), germacreno D (12,1%) y α-humuleno (11,5%). Además, el aceite esencial demostró efectos citotóxicos contra las células tumorales A549 en una concentración de 4µg/mL (EC50) (p < 0.05).

Efecto citotóxico de los compuestos de inclusión de paladio (II) en la beta-ciclodextrina / Cytotoxic effect of palladium (II) inclusion compounds in beta-cyclodextrin

Resumen Introducción. Las tiosemicarbazonas y sus complejos de paladio (II) poseen actividad antineoplásica con pocos efectos secundarios, por lo cual se las considera como una nueva alternativa terapéutica. Sin embargo, existen diferencias en los rangos de la concentración inhibitoria media (CI50) asociada a la divergencia estructural y la solubilidad de los complejos, así como a la sensibilidad de los blancos celulares. La inclusión de fármacos en la beta-ciclodextrina con fines terapéuticos ha mejorado su solubilidad y estabilidad, pero los efectos de su combinación con los complejos de paladio (II) y las tiosemicarbazonas no se han comprobado aún. Objetivo. Estudiar el efecto citotóxico de los complejos de paladio en la beta-ciclodextrina. Materiales y métodos. La actividad citotóxica de los complejos de paladio en la beta-ciclodextrina se evaluó en la línea celular de cáncer de mama (MCF-7), empleando el método de la sulforodamina B. Resultados. Los ligandos MePhPzTSC y Ph2PzTSC, sus complejos de paladio (II) libres e incluidos en la beta-ciclodextrina y el cisplatino mostraron actividad citotóxica en la línea celular MCF-7; sin embargo, la citotoxicidad fue mayor con la inclusión en la beta-ciclodextrina ([Pd(MePhPzTSC)2]•ß-CD y [Pd(Ph2PzTSC)2]•ß-CD). La concentración inhibitoria media (CI50) para estos complejos se obtuvo en concentraciones de 0,14 y 0,49 μM, y con dosis hasta cinco veces inferiores comparadas con las concentraciones de los ligandos libres (1,4 y 2,9 μM), de los complejos de paladio (II) libres (0,57 y 1,24 μM) y del cisplatino (6,87 μM). Conclusiones. El uso de la beta-ciclodextrina mejoró significativamente la actividad citotóxica de las tiosemicarbazonas y sus complejos de paladio (II), lo cual probablemente está asociado al incremento de la solubilidad y biodisponibilidad del compuesto, estrategia que se puede sugerir para el diseño de futuros fármacos antineoplásicos.

Abstract Introduction: Thiosemicarbazones and palladium (II) complexes have antineoplastic activities with mild side effects, for which they are considered new alternative antineoplastic drugs. However, the IC50 ranges of these complexes vary due to differences in their structure and solubility and their sensitivities for various cellular targets. Beta-cyclodextrin is an additive used to improve the solubility and stability of various drugs for therapeutic use, but the combination of beta-cyclodextrin with palladium (II) complexes and thiosemicarbazones has not been tested yet. Objective: To study the cytotoxic effect of palladium (II) inclusion complexes in beta-cyclodextrin. Materials and methods: We tested the cytotoxic activity of palladium complexes combined with betacyclodextrin in the breast cancer cell line MCF-7 using a sulforhodamine B assay. Results: We tested the antiproliferative activity of palladium (II) complexes with and without the ligands MePhPzTSC and Ph2PzTSC and with and without beta-cyclodextrin in MCF-7 cells and compared them to that of cisplatin. All combinations showed antiproliferative activity; however, the activity was greater for the combinations that included beta-cyclodextrin: ([Pd (MePhPzTSC) 2] • ß-CD and [Pd (Ph2PzTSC) 2] • ß-CD), at concentrations of 0.14 and 0.49 μM, respectively. The IC50 for this complex was 5-fold lower than that of the ligand-free combinations (1.4 and 2.9 μM, respectively). The IC50 for free palladium (II) complex was 0.571.24 μM and that for cisplatin was 6.87 μM. Conclusions: Beta-cyclodextrin significantly enhanced the cytotoxic activities of palladium (II) complexes and thiosemicarbazones probably by improving their solubility and bioavailability. The addition of betacyclodextrin is a possible strategy for designing new anticancer drugs.

Cytotoxic activity of Androctonus australis hector venom and its toxic fractions on human lung cancer cell line

Several studies have showed that animal venoms are a source of bioactive compounds that may inhibit the growth of cancer cells, which makes them useful agents for therapeutic applications. Recently, it was established that venom toxins from scorpions induced cytotoxic, antiproliferative and apoptogenic effects on cancer cells. Therefore, the present study aims to investigate the cytotoxic activity of Androctonus australis hector (Aah) scorpion venom and its toxic fractions (FtoxG-50 and F3) on NCI-H358 human lung cancer cells. Methods: The cytotoxic and antiproliferative activities were estimated using MTT assay, lactate dehydrogenase release and clonogenic assays. Apoptosis was evaluated by Hoechst 33258 staining, DNA fragmentation assay and caspase-3 activity. Oxidative stress was analyzed by reactive oxygen species, nitric oxide, malondialdehyde and protein carbonyl levels along with assessment of antioxidant status. In addition, alteration of mitochondrial membrane potential was analyzed by JC1 fluorescent dye. Results: The present findings showed that F3 fraction was more cytotoxic towards NCI-H358 lung cancer cells with an IC50 of 27.05 ± 0.70 g/mL than venom alone (396.60 ± 1.33 g/mL) and its toxic fraction FtoxG-50 (45.86 ± 0.91 g/mL). Nevertheless, F3 fraction was not cytotoxic at these concentrations on normal human lung fibroblast MRC-5 cells. Inhibition of NCI-H358 cell proliferation after F3 fraction exposure occurred mainly by apoptosis as evidenced by damaged nuclei, significant DNA fragmentation level and caspase-3 activation in a dose dependent manner. Moreover, F3 fraction enhanced oxidative and nitrosative stress biomarkers and dissipated mitochondrial membrane potential in lung cancer cells along with significant depletion in cellular enzymatic and non-enzymatic antioxidants. Further, the apoptosis induced by F3 fraction was markedly prevented by the antioxidant N-acetylcysteine (NAC) suggesting the potential mechanism of oxidative stress. Conclusion: These findings suggest that F3 fraction could induce apoptosis in lung cancer cells through involvement of oxidative stress and mitochondrial dysfunction. Hence, these properties make F3 fraction a promising candidate for development of new anticancer agents.

Antileishmanial activity of the essential oil from Tetradenia riparia obtained in different seasons

The herbaceous shrub Tetradenia riparia has been traditionally used to treat inflammatory and infectious diseases. Recently, a study showed that T. riparia essential oil (TrEO) obtained in summer has antileishmanial effects, although these results could be influenced by seasonal variation. This study evaluated the activity of the TrEO obtained in different seasons against Leishmania (Leishmania) amazonensis, in vitro and in vivo. The compounds in the TrEO were analysed by gas chromatography-mass spectrometry; terpenoids were present and oxygenated sesquiterpenes were the majority compounds (55.28%). The cytotoxicity and nitric oxide (NO) production were also tested after TrEO treatment. The TrEO from all seasons showed a 50% growth inhibitory concentration for promastigotes of about 15 ng/mL; at 30 ng/mL and 3 ng/mL, the TrEO reduced intracellular amastigote infection, independently of season. The TrEO from plants harvested in summer had the highest 50% cytotoxic concentration, 1,476 ng/mL for J774.A1 macrophages, and in spring (90.94 ng/mL) for murine macrophages. NO production did not change in samples of the TrEO from different seasons. The antileishmanial effect in vivo consisted of a reduction of the parasite load in the spleen. These results suggest that the TrEO has potential effects on L. (L.) amazonensis, consonant with its traditional use to treat parasitic diseases.

Antiplasmodial activity of iron(II) and ruthenium(II) organometallic complexes against Plasmodium falciparum blood parasites

This work reports the in vitro activity against Plasmodium falciparumblood forms (W2 clone, chloroquine-resistant) of tamoxifen-based compounds and their ferrocenyl (ferrocifens) and ruthenocenyl (ruthenocifens) derivatives, as well as their cytotoxicity against HepG2 human hepatoma cells. Surprisingly with these series, results indicate that the biological activity of ruthenocifens is better than that of ferrocifens and other tamoxifen-like compounds. The synthesis of a new metal-based compound is also described. It was shown, for the first time, that ruthenocifens are good antiplasmodial prototypes. Further studies will be conducted aiming at a better understanding of their mechanism of action and at obtaining new compounds with better therapeutic profile.

Cytotoxicity and hepatoprotective attributes of methanolic extract of Rumex vesicarius L

BACKGROUND: To evaluate the hepatoprotective potential and invitro cytotoxicity studies of whole plant methanol extract of Rumex vesicarius L. Methanol extract at a dose of 100 mg/kg bw and 200 mg/kg bw were assessed for its hepatoprotective potential against CCl4-induced hepatotoxicity by monitoring activity levels of SGOT (Serum glutamic oxaloacetic transaminase), SGPT (Serum glutamic pyruvic transaminase), ALP (Alkaline phosphatase), TP (Total protein), TB (Total bilirubin) and SOD (Superoxide dismutase), CAT (Catalase), MDA (Malondialdehyde). The cytotoxicity of the same extract on HepG2 cell lines were also assessed using MTT assay method at the concentration of 62.5, 125, 250, 500 µg/ml. RESULTS: Pretreatment of animals with whole plant methanol extracts of Rumex vesicarius L. significantly reduced the liver damage and the symptoms of liver injury by restoration of architecture of liver. The biochemical parameters in serum also improved in treated groups compared to the control and standard (silymarin) groups. Histopathological investigation further corroborated these biochemical observations. The cytotoxicity results indicated that the plant extract which were inhibitory to the proliferation of HepG2 cell line with IC50 value of 563.33 ± 0.8 Mg/ml were not cytotoxic and appears to be safe. CONCLUSIONS: Rumex vesicarius L. whole plant methanol extract exhibit hepatoprotective activity. However the cytotoxicity in HepG2 is inexplicable and warrants further study.

Methanol extract from Vietnamese Caesalpinia sappan induces apoptosis in HeLa cells

BACKGROUND: This study evaluated the cytotoxic activity of extracts from Caesalpinia sappan heartwood against multiple cancer cell lines using an MTT cell viability assay. The cell death though induction of apoptosis was as indicated by DNA fragmentation and caspase-3 enzyme activation. RESULTS: A methanol extract from C. sappan (MECS) showed cytotoxic activity against several of the cancer cell lines. The most potent activity exhibited by the MECS was against HeLa cells with an IC50 value of 26.5 ± 3.2 µg/mL. Treatment of HeLa cells with various MECS concentrations resulted in growth inhibition and induction of apoptosis, as indicated by DNA fragmentation and caspase-3 enzyme activation. CONCLUSION: This study is the first report of the anticancer properties of the heartwood of C. sappan native to Vietnam. Our findings demonstrate that C. sappan heartwood may have beneficial applications in the field of anticancer drug discovery.

Extraction of saponins and toxicological profile of Teucrium stocksianum boiss extracts collected from District Swat, Pakistan

BACKGROUND: The current era is facing challenges in the management of neoplasia and weeds control. The currently available anti-cancer and herbicidal drugs are associated with some serious side effects. Therefore numerous researchers are trying to discover and develop plant based alternative particularly for the rational management of cancer and weed control. Teucrium stocksianum possess antioxidant and analgesic activities. The current study was designed to evaluate crude saponins (CS), methanolic extract and sub-fractions of T. stocksianum for cytotoxic and phytotoxic potentials. CS, methanolic extract and sub-fractions were extracted from powdered plant material using different solvents. Cytotoxic potential of the extracts at a dose of 10, 100 and 1000 µg/ml were evaluated against Brine shrimp's nauplii. Phytotoxic assay also performed at the same concentration against Lemna minor. Etoposide and Paraquat were used as positive controls in cytotoxic and phytotoxic assays respectively. RESULTS: The percent yield of crude saponins was (5%). CS demonstrated tremendous brine shrimp lethality showing < 10 µg/ml LC50. The n-hexane (HF) and chloroform fractions (CF) demonstrated excellent cytotoxicity with 80 and 55 µg/ml LC50 respectively. Whereas the methanolic extract (TSME), ethyl acetate (EAF) and aqueous fractions (AF) revealed moderate cytotoxicity showing 620, 860 and 1000 µg/ml LC50 values respectively. In phytotoxic assay profound inhibition was displayed by HF (96.67%) and TSME (95.56%, 30 µg/ml LC50) against the growth of Lemna minor at 1000 µg/ml respectively. Both CF and EAF demonstrated profound phytoxicity (93.33%) respectively at highest concentration (1000 µg/ml), while AF and CS demonstrated weak phytotoxicity with 1350 and 710 µg/ml LC50 values respectively. CONCLUSION: Cytotoxicity and phytotoxicity assays indicated that the crude saponins, n-hexane and chloroform fractions of T. stocksianum could play a vital role in the treatment of neoplasia and as potential natural herbicides. Therefore these sub-fractions are recommended for further investigation with the aim to isolate novel anti-cancer and herbicidal compounds.

In vivo antipyretic, antiemetic, in vitro membrane stabilization, antimicrobial, and cytotoxic activities of different extracts from Spilanthes paniculata leaves

BACKGROUND: The study was conducted to evaluate the in vitro antimicrobial activity, cytotoxic, and membrane stabilization activities, and in vivo antiemetic and antipyretic potentials of ethanolic extract, n-hexane and ethyl acetate soluble fractions of Spilanthes paniculata leaves for the first time widely used in the traditional treatments in Bangladesh. RESULTS: In antipyretic activity assay, a significant reduction (P < 0.05) was observed in the temperature in the mice tested. At dose 400 mg/kg-body weight, the n-hexane soluble fraction showed the effect (36.7 ± 0.63°C ) as like as the standard (dose 150 mg/kg-body weight) after 5 h of administration. Extracts showed significant (P < 0.001) potential when tested for the antiemetic activity compared to the standard, metoclopramide. At dose 50 mg/kg-body weight, the standard showed 67.23% inhibition, whereas n-hexane and ethyl acetate soluble fractions showed 37.53% and 24.93% inhibition of emesis respectively at dose 400 mg/kg-body weight. In antimicrobial activity assay, the n-hexane soluble fraction (400 µg/disc) showed salient activity against the tested organisms. It exerts highest activity against Salmonella typhi (16.9 mm zone of inhibition); besides, crude, and ethyl acetate extracts showed resistance to Bacillus cereus and Bacillus subtilis, and Vibrio cholera respectively. All the extracts were tested for lysis of the erythrocytes. At the concentration of 1mg/ml, ethanol extract, and n-hexane and ethyl acetate soluble fractions significantly inhibited hypotonic solution induced lysis of the human red blood cell (HRBC) (27.406 ± 3.57, 46.034 ± 3.251, and 30.72 ± 5.679% respectively); where standard drug acetylsalicylic acid (concentration 0.1 mg/ml) showed 77.276 ± 0.321% inhibition. In case of heat induced HRBC hemolysis, the plant extracts also showed significant activity (34.21 ± 4.72, 21.81 ± 3.08, and 27.62 ± 8.79% inhibition respectively). In the brine shrimp lethality bioassay, the n-hexane fraction showed potent (LC50 value 48.978 µg/ml) activity, whereas ethyl acetate fraction showed mild (LC50 value 216.77 µg/ml) cytotoxic activity. CONCLUSIONS: Our results showed that the n-hexane extract has better effects than the other in all trials. In the context, it can be said that the leaves of S. paniculata possess remarkable pharmacological effects, and justify its folkloric use as antimicrobial, antipyretic, anti-inflammatory, and antiemetic agent. Therefore, further research may be suggested to find possible mode of action of the plant part.

In vivo and in vitro anti-inflammatory activity of Cryptostegia grandiflora Roxb. ex R. Br. leaves

BACKGROUND: Despite Cryptostegia grandiflora Roxb. ex R. Br. (Apocynaceae) leaves are widely used in folk Caribbean Colombian medicine for their anti-inflammatory effects, there are no studies that support this traditional use. Therefore, this work aimed to evaluate the effect of the total extract and primary fractions obtained from Cryptostegia grandiflora leaves, using in vivo and in vitromodels of inflammation, and further get new insights on the mechanisms involved in this activity. RESULTS: Ethanolic extract of Cryptostegia grandiflora leaves, and its corresponding ether and dichloromethane fractions, significantly reduced inflammation and myeloperoxidase activity (MPO) in ear tissue of mice treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Histological analysis revealed a reduction of edema and leukocyte infiltration. Complementarily, we demonstrated that extract and fractions reduced nitric oxide (NO•) and prostaglandin E2 (PGE2) production in LPS-stimulated RAW 264.7 macrophages, as well as scavenging activity on DPPH and ABTS radicals. CONCLUSIONS: Our results demonstrated for the first time the anti-inflammatory activity of Cryptostegia grandiflora leaves, supporting its traditional use. This activity was related to inhibition of MPO activity, and PGE2 and NO• production. These mechanisms and its antioxidant activity could contribute, at least in part, to the anti-inflammatory effect showed by this plant.

Análise da citotoxicidade do extrato do fruto de juçara (Euterpe oleracea Mart) do Maranhão em células malignas humanas / Analysis of cytotoxicity of fruit extract juçara (euterpe oleracea mart) of Maranhão in human malignant cells

A juçara, Euterpe oleracea Mart., fruta indígena da Amazônia Legal, é rica em fitoquímicos com atividades anti-oxidante, antiinflamatória e anti-câncer. Este estudo tem por objetivo analisar os efeitos do extrato hidroalcoólico da casca, caroço e fruto total da juçara em diferentes linhagens de células malignas humana. Os frutos foram coletados no Parque da Juçara, localizado no Maracanã, município de São Luís, seguida da confecção da excicata que se mantém registrada no Herbário Rosa Mochel do Núcleo de Estudos Biológicos da Universidade Estadual do Maranhão. Os extratos hidroalcoólicos da casca, caroço e fruto total foram extraidos no Laboratório de Farmacologia e Psicobiologia da UERJ. As linhagens celulares utilizadas nos ensaios foram MCF-7 (adenocarcinoma de mama), CACO-2 e HT-20 (adenocarcinoma colo retal) e adenocarcinoma na mama (MDA-MB-468). As linhagens foram tratadas com 10, 20 e 40µg/mL dos extratos por 24 e 48 horas e feitas às análises. Células MCF-7 controle apresentaram núcleo proeminente com nucléolos evidentes. Após tratamento com o extrato hidroalcoólico da casca da juçara, as células mostraram morfologia arredondada com retração do citoplasma. O ensaio de viabilidade com MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)) demonstrou uma redução na viabilidade das células. Após 48 horas, o tratamento das células com 20µg/mL do extrato da casca reduziu a viabilidade sendo que o efeito citotóxico do tratamento com 40µg/mL do extrato da casca foi potencializado. Células tratadas com 10µg/mL do extrato do caroço de juçara apresentavam-se arredondadas com consequente redução no volume celular. A concentração 20µg/mL de extrato hidroalcoólico do caroço, causou severa redução no volume das células e ocasionou o surgimento de vacúolos intracelulares. O mesmo foi observado após tratamento com 40µg/mL. O tratamento com 40µg/mL do extrato hidroalcoólico do fruto total, modificou drasticamente a morfologia das células MCF-7...

Juçara, Euterpe oleracea Mart., an indigenous fruit from Amazon, is rich in phytochemicals with antioxidant, anti-inflammatory and anti-cancer activity. This study aims to analyze the effects of the hydroalcoholic extract of the bark, seed and total fruit of juçara in different human malignant cell lines. Fruits were collected at the Maracana Ecological Park, in São Luís, followed by excicata manufacturing that remains registered in the Herbarium Rosa Mochel from the Nucleus of Biological Studies at the State University of Maranhão. The hydroalcoholic extracts of bark, seed and fruit were all obtained in the Laboratory of Pharmacology and Psychobiology UERJ. The cell lines used in the tests were MCF-7 and MDA-MB-468 (breast adenocarcinoma) and CACO-2 and HT-20 (colorectal adenocarcinoma). Strains were treated with 10, 20 and 40μg/mL of extracts for 24 and 48 hours. Control MCF-7 cells showed prominent nucleus with evident nucleoli. After treatment with the hydroalcoholic extract from the bark of juçara, the cells showed rounded morphology with retraction of the cytoplasm. The MTT viability assay showed a reduction in cell viability. After 48 hours, treatment of cells with 20μg/mL of bark extract reduced cell viability and the cytotoxic effect of treatment with 40μg/mL extract of the bark was potentiated. Cells treated with 10μg/mL of the bark extract were rounded with consequent reduction in cell volume. The concentration of 20μg/mL of bark extract caused severe reduction in volume of the cells and caused the appearance of intracellular vacuoles. The same was observed after treatment with 40μg/mL. Treatment with 40μg/mL of the hydroalcoholic extract of total fruit dramatically changed the morphology of the MCF-7 cells causing vacuolization and lysis with apparent loss of cytoplasmic contents. MTT assay showed a reduction in viability of MCF-7 cells treated with 20 and 40μg/mL after 24 hours of treatment. Analysis by electron microscopy showed the appearance...

Selection of phytotoxin producing rhizobacteria

In order to select phytotoxin producing rhizobacteria to control weed plants, twenty five bacterial strains previously isolated from the rhizospheres of various plants were grown in a liquid medium and, after cell removal by centrifugation, the liquid phases were freeze-dried and the products were extracted with ethyl acetate/methanol. The extracts were concentrated to dryness under vacuum and dissolved in water and sucrose solution to be submitted to in vitro assays of lettuce (Lactuca sativa L.) seed germination and wheat (Triticum aestivum L.) coleoptile growth. Although most samples affected coleoptile growth, only those from four strains reduced lettuce seed germination. Two strains of Bacillus cereus, one strain of B. pumilus and one of Stenotrophoonas altophilia were the most promising microorganisms for producing phytotoxin and, consequently, for the development of new weed control products.

Com o objetivo de selecionar rizobactérias produtoras de fitotoxinas para uso no controle de plantas daninhas, vinte e cinco isolados bacterianos previamente obtidos das rizosferas de diferentes plantas foram cultivados em meio líquido e, após remoção das células por centrifugação, as fases líquidas foram liofilizadas e os resíduos obtidos foram submetidos à extração com acetato de etila/metanol. Os extratos foram concentrados sob vácuo até secura e dissolvidos em água e solução de sacarose para serem submetidos a testes in vitro de germinação de sementes de alface (Lactuca sativa L.) e de crescimento de coleóptilos de trigo (Triticum aestivum L.). Embora a maior parte das amostras tenha desfavorecido o crescimento dos coleóptilos de trigo, somente as provenientes de quatro isolados reduziram a germinação das sementes de alface. Dois isolados de Bacillus cereus, um isolado de B. pumilus e um de Stenotrophomonas maltophilia foram os microrganismos mais promissores para a produção de fitotoxinas, com possibilidade de uso no desenvolvimento de novos produtos para o controle de plantas daninhas.

In vitro anticancer activity of microbial isolates from diverse habitats / In vitro atividade anticancerígena de isolados microbianos de diversos habitats

Extracts from natural products, especially microorganisms, have served as a valuable source of diverse molecules in many drug discovery efforts and led to the discovery of several important drugs. Identification of microbial strains having promising biological activities and purifying the bio-molecules responsible for the activities, have led to the discovery of many bioactive molecules. Extracellular, as well as intracellular, extracts of the metabolites of thirty-six bacterial and twenty-four fungal isolates, grown under unusual conditions such as high temperature, high salt and low sugar concentrations, were in vitro tested for their cytotoxic potential on various cancer cell lines. The extracts were screened on HeLa and MCF-7 cell lines to study the cytotoxic potential. Nuclear staining and flow cytometric studies were carried out to assess the potential of the extracts in arresting the cell cycle. The crude ethylacetate extract of isolate F-21 showed promising results by MTT assay with IC50 as low as 20.37±0.36 µg/mL on HeLa, and 44.75±0.81 µg/mL on MCF-7 cells, comparable with Cisplatin. The isolate F-21 was identified as Aspergillus sp. Promising results were also obtained with B-2C and B-4E strains. Morphological studies, biochemical tests and preliminary chemical investigation of the extracts were also carried out.

Extratos de produtos naturais, especialmente de microrganismos, constituíram-se em fonte valiosa de diversas moléculas em muitas descobertas de fármacos e levaram à descoberta de fármacos importantes. A identificação de espécies microbianas que apresentam atividade biológica e a purificação de biomoléculas responsáveis pelas atividades levou à descoberta de muitas moléculas bioativas. Extratos extracelulares tanto quanto intracelulares de metabólitos de 36 isolados de bactérias e 24 isolados de fungos, que cresceram sob condições não usuais, como alta temperatura, alta concentração de sal e baixa concentração de açúcar, foram testados in vitro quanto ao seu potencial citotóxico em várias linhagens de câncer. Os extratos foram ensaiados em células HeLa e MCF-7 para o estudo do potencial citotóxico. A coloração nuclear e os estudos de citometria de fluxo foram realizados para avaliar o potencial dos extratos em bloquear o ciclo celular. O extrato bruto em acetato de etila do isolado F-21 mostrou resultados promissores no ensaio de MTT, com IC50 de 20,37±0,36 µg/mL em células HeLa e 44,.75±0,81 µg/mL em células MCF-7, comparativamente à cisplatina. O isolado F-21 foi identificado como Aspergillus sp. Resultados promissores foram obtidos com cepas B-2C e B-4E. Realizaram-se, também, estudos morfológicos, testes bioquímicos e investigação química preliminar dos extratos.

Cytotoxicity of isolated compounds from the extracts of Struchium sparganophora [Linn] Ktze asteraceae

Chemical investigation of the leaves of Struchium sparganophora by the application of VLC, CL and PTLC resulted in isolation of three compounds. The cytotoxicity activity of these compounds on malignant human cultured cells was examined. Vernodalin showed a significant cytotoxic activity on the melanoma and ovarian cancer cell lines [P<0.05] while the conjugated 3 methyl, 2, 6 hexacosedienol and luteolin caused cell death after 48h reculture without them. These compounds portend an effective remedy if subjected to structural modification to enhance its' efficacy and the dietary importance of this plant as a culinary herb in west Africa countries is evidence by the presence of these antitumour compounds in this plant

antifungal, cytotoxic, antitermite and insecticidal activities of zizyphus jujube

Plants are very useful, self-generating machines, producing a variety of useful bioactive products. Keeping in view this idea, the crude methanolic extract and various fractions of Zizyphus jujuba were screened for antifungal, cytotoxic, antitermite and insecticidal activities. Low activity was shown by the crude methanolic extract [12%], n-hexane [9%], chloroform [20%] and ethyl acetate [14%] fraction against Penicillium notatum. Low activity was shown by the ft-hexane fraction against Aspergillus niger [10%] and Trichoderma harzianum [13%] and inactive against Aspergillus flavus, Fusarium oxysporum and Rhizopus stolonifer. The CHC1[3] fraction exhibited low activity of 10% against F. oxysporum while showing no activity against the rest of the test fungi. All the test samples were inactive against Rhizopus stolonifer. The crude methanolic extract was highly cytotoxic [73.33%] at the concentration of 1000 [microg/ml] while the rest of the test samples were low in toxicity at the same concentration. The crude methanolic extract of Zizyphus jujuba showed significant antitermite activity against Heterotermes indicola, among the test samples. Against Tribolium castaneum, Rhizopertha dominica and Callosbruchus analis the insecticidal activity was determined. All the test samples except rc-hexane showed low activity [20%] against T. castaneum. The w-hexane fraction showed low activity [20%] against R. dominica while the rest of the fractions were inactive against it. Low activity of 40% and 20% was shown by the chloroform and "-hexane fraction respectively against C. analis. The results of the present study revealed that the plant could be as potent source of cytotoxic drugs

Differentiation of Candida dubliniensis from Candida albicans with the use of killer toxins / Avaliação das toxinas killer na diferenciação entre Candida albicans e Candida dubliniensis

The aim of this study was to report the ability of killer toxins, previously used as biotyping techniques, as a new tool to differentiate C. albicans from C. dubliniensis. The susceptibility of C. albicans and C. dubliniensis to killer toxins ranged from 33.9 to 93.3 percent and from 6.67 to 93.3 percent, respectively.

Avaliou-se a capacidade das toxinas killer, previamente utilizadas na biotipagem de C. albicans, como método para diferenciar C. albicans de C. dubliniensis. A susceptibilidade de C. albicans e C. dubliniensis às toxinas killer variou de 33,9 por cento a 93,3 por cento para C. albicans e de 6,67 por cento a 93,3 por cento para C. dubliniensis.

Germinating seeds of the mung bean, Vigna radiata (Fabaceae), as a model for the preliminary evaluation of cytotoxic effects of drugs

Cytotoxic properties of plant extracts and drugs being developed for cancer treatment are usually evaluated by a variety of in vivo and in vitro tests carried out in animal or plant based models. In the present study we have evaluated the possibility of using the germinating mung beans (Vigna radiata), for rapid and inexpensive screening of drugs exhibiting cytotoxic properties. Mung beans were allowed to germinate either in tap water or in different drug solutions, and parameters like percent germination, increase in radicle length, change in seedling weight and mitotic index of apical root meristems were determined at two time intervals coinciding with the time at which the radicle length in control group was 1.0 to 1.5 cm (time 0, T0) and 48 h later (T48). Methanol extract of Calotropis procera latex as well as drugs like podophyllotoxin, cyclophosphamide, cyproheptadine and aspirin produced a dose-dependent inhibitory effect on seed germination, seed weight gain, radicle growth and mitotic index in the radicle meristems. The inhibitory effect of some of the drugs tested was associated with reduction in water imbibition. Some of the drugs at higher concentrations allowed seed germination to take place but produced radicle decay and seedling weight loss. Our study shows that germinating V radiata beans could be used as a convenient model for the preliminary screening of drugs exhibiting cytotoxic properties.

Investigação da citotoxicidade e mutagenicidade do hipocolesteremiante sinvastatina em células de ratos wistar e de Allium cepa L / Investigation of the cytotoxicity and mutagenicity of simvastatin hypocholesteremiant in cells of wistar rats and Allium cepa L

In the field of pharmacological research is important to assess the potential cytotoxic and/or mutagenic widely of synthetic drugs prescribed. Due to intense use by the population of the drug simvastatin (Zocor) for the reduction of cholesterol, this study aimed to evaluate the cytotoxicity and mutagenicity of this drug in bone marrow cells of Wistar rats treated in vivo, via gavage, in acute treatment, in concentrations of 0.0015, 0015 and 0.15 mg/mL, and in root meristematic cells of Allium cepa L., in concentrations of 0.10, 10.0 and 100.0 mg/mL. In the two-test system used, the tested concentrations of simvastatin did not cause statistically significant changes by the chi-square test, the rate of cell division, showed no cytotoxic activity. In the animal test system, the Zocor, in concentrations evaluated, caused no significant increase in chromosomal alterations, not present, therefore, mutagenic effects, in this type and form of treatment, and concentrations evaluated. The results obtained in this work serve to aggregate data for work done with other systems-test, for assessing the effect of simvastatin on cellular level.

No campo das investigações farmacológicas é importante avaliar o potencial citotóxico e/ou mutagênico de medicamentos sintéticos amplamente prescritos. Devido ao intenso uso pela população do fármaco sinvastatina (Zocor) para a redução do colesterol, este trabalho teve por objetivo avaliar a citotoxicidade e a mutagenicidade deste medicamento em células de medula óssea de Ratos Wistar, tratados in vivo, via gavagem, em tratamento agudo, nas concentrações de 0,0015; 0,015 e 0,15 mg/mL, e em células meristemáticas de raiz de Allium cepa L., nas concentrações de 0,10; 10,0 e 100,0mg/mL. Nos dois sistemas-teste utilizados, as concentrações testadas da sinvastatina não causaram mudanças, estatisticamente significativas, pelo teste do qui-quadrado, no índice de divisão celular, não apresentando ação citotóxica. No sistema teste animal, o Zocor, nas concentrações avaliadas, não causou aumento significativo das alterações cromossômicas, não apresentando, portanto, efeito mutagênico, neste tipo e forma de tratamento, e nas concentrações avaliadas. Os resultados obtidos neste trabalho servirão para agregar dados a trabalhos feitos, com outros sistemas-teste, referentes à avaliação da ação da sinvastatina em nível celular.

Cytotoxic, mutagenic and antimutagenic screening of Arenosclera brasiliensis acetone and ethanol extracts

The marine environment is a rich source of biologically active compounds with pharmacological properties. Marine organisms often produce secondary metabolites with structural features different from those produced by terrestrial ones, and the Phylum Porifera seems to be one of the most productive in this sense. This study was undertaken to provide data on mutagenic and antimutagenic activities from an acetone (Areac) and an ethanol (Areet) extract obtained from Arenosclera brasiliensis, an endemic Brazilian sponge. A qualitative Salmonella reverse mutation test was performed with the TA97, TA98, TA100, and TA102 strains by incubating cells with Areac and Areet in the presence and absence of a known mutagen. A cytotoxic evaluation of the extracts was also performed. A. brasiliensis did not display any mutagenic activity, but Areac showed significant toxicity against test strains. In the antimutagenic assay, a reduction in the number of his+ revertants was observed for the TA97, TA100 and TA102 strains treated with Areac when compared to the positive controls. Areet treatment showed protective activity against DNA lesions only for the TA100. These results are in agreement with those obtained previously with other A. brasiliensis extracts, suggesting an antimutagenic activity.