Caracasine, An ent-kaurane Diterpene with Proapoptotic and Pro-differentiator Activity in Human Leukaemia Cell Lines.

BACKGROUND: Kaurane-type diterpenoids, obtained from various natural sources, have shown many biological activities, including anti-inflammatory and antitumor effects. Caracasine, an ent-kaurane diterpenoid isolated from the flowers of Croton micans, was shown to induce apoptosis in leukaemia cell lines. OBJECTIVE: The present study aimed to ascertain the compound's mechanism of cell death induction using two leukaemia cell lines, Jurkat E6.1 (T cell) and HL-60 (promyeloblast cells). METHODS: Cell death in Jurkat and HL60 cells were evaluated by flow cytometry for apoptosis with annexin-V/PI, mitochondrial membrane potential disturbance, changes in cell cycle, CD95 expression, caspase activation, Nuclear Factor kappa B inhibition, and differentiation into a neutrophil-like cell (dHL60). RESULTS: Caracasine (10 µM) increased the G0/G1 phase in Jurkat and arrested the cell cycle in the S phase in HL60. Caracasine increased CD95 expression (p<0.01 in Jurkat and p<0.05 in HL60) and caspase-8 activation (p<0.001 in Jurkat and p<0.05 in HL60). Caspase-9 was activated in both cell lines (p<0.001) along with the decline in mitochondrial Δψm (p<0.05 in Jurkat and p<0.001 in HL60). In HL60 cells, the kaurane induced neutrophil differentiation was assessed by CD40 expression and reactive oxygen species production. In Jurkat cells, caracasine inhibited the NF-κB pathway in cells pretreated with PHA to activate the NF-κB pathway, suggesting a possible role in inflammatory diseases. CONCLUSION: Caracasine induced apoptosis through the intrinsic and extrinsic pathways in both cell lines were evaluated which could be the leading structure for new anti-leukemic and anti-inflammatory drugs.

Caracasine acid, an ent-3,4-seco-kaurene, promotes apoptosis and cell differentiation through NFkB signal pathway inhibition in leukemia cells.

Caracasine acid (CA) is an ent-3,4-seco-kaurene isolated from the plant Croton micans. Decreased cancer cell lines viability was reported upon CA treatment. The present study aimed to investigate the mechanism of CA induced cytotoxicity using two human cell lines, Jurkat E6.1 (human cell T lymphoma) and HL-60 (human acute promyelocytic leukemia). Significant increases of apoptotic cell death markers upon CA treatment were observed: annexin-V positiveness, potential mitochondrial disturbances, cell cycle changes, caspase activation, and CD95 expression. These effects were not detected in normal lymphocytes. CA induced the appearance of Bax, cleaved caspase 3, and cytochrome c release in Jurkat cells, and cleaved caspase 3 and phosphorylated p53 in HL60 cells. Likewise, downregulation of anti-apoptotic proteins such as Bcl-x (Jurkat), Bcl-2, and XIAP (HL60) was observed with CA treatment. Both pathways, intrinsic and extrinsic were activated when cell lines were treated with CA. NF-κB p65 inhibition was observed in Jurkat cells and cell differentiation in HL-60 cells. CA could be a potential leader compound for the development of new drugs for leukemia treatment in humans.

Synthesis and biological evaluation of caracasine acid derivatives.

A series of caracasine acid (1) derivatives were synthesized and evaluated for their in vitro cytotoxicity on human cancer-derived cell lines MCF-7 and PC-3, as well as for other activities such as antibacterial, antileishmanial and antitrypanosomal activity. Compound 1 was more effective than any of its derivatives against tested human cancer cell lines. PC-3 cells were more sensitive than MCF-7 to all compounds, particularly the methyl ester (2), the amide (9) and the epoxide (10). The evaluation of antiparasitic activity revealed that ester derivatives (2-8) and the amide derivative (9) were the most effective antileishmanial and antitrypanosomal compounds, even though their effect on Trypanosoma cruzi was modest. Finally, compound 1 and the derivatives evidenced a broad spectrum of antibacterial activity, as assayed against Gram-positive and Gram-negative bacteria.

Crotofolane diterpenoids from Croton caracasanus.

Four new crotofolane-type diterpenoids, crotocarasin (A-D) (1-4), together with the known crotofolin E, were isolated from a dichloromethane extract of the stems of Croton caracasanus Pittier. The structures of the new compounds were determined by spectroscopic methods, and the structure of 3 was further confirmed by single-crystal X-ray data analyses.

Caracterización de la resistencia in vitro a diferentes antimicrobianos en cepas de Staphylococcus spp. en una institución hospitalaria de la ciudad de Valledupar entre enero y julio de 2009 / Characterization of resistance in vitro to different antimicrobial in strains of Staphylococcus spp. in a hospital of the city of Valledupar between January and July 2009 / Caracterização da resistência in vitro a diferentes antimicrobianos em cepas de Staphylococcus spp. em uma instituição hospitalaria da cidade de Valledupar entre janeiro e julho de 2009

Los Staphylococcus spp. causan un amplio rango de infecciones sistémicas y localizadas en pacientes hospitalizados y comunitarios. Su alta patogenicidad y su creciente resistencia a múltiples antimicrobianos, entre ellos la meticilina, provocan elevadas tasas de morbimortalidad ocasionando un alto impacto epidemiológico. Objetivo: determinar el perfil fenotípico de resistencia a diferentes antimicrobianos en cepas del género Staphylococcus spp. Materiales y métodos: se recolectaron setenta y cinco cepas y se determinó susceptibilidad a diferentes antibióticos por el método de Kirby Bauer. La producción de beta-lactamasa se verificó mediante la prueba del nitrocefin. La resistencia a la meticilina en S. aureus se realizó usando Mueller Hinton con 4% de NaCl y oxacilina 6 µg/mL. La resistencia inducible a clindamicina se tamizó mediante la prueba del D-Test. Resultados: se aisló un 38% de estafilococos coagulasa negativa (SCN) y un 62% de S. aureus. Un 53% de los estafilococos fueron resistentes a penicilina: S. aureus con 58% y SCN 42%; un 47% de las cepas presentaron resistencia a meticilina: S. aureus con un 61% y SCN con un 39%; una cepa de S. aureus mostró resistencia inducible a la clindamicina (1,33%). En su mayoría, los estafilococos coagulasa negativa fueron aislados a partir de muestras de hemocultivos (31%) y los estafilococos meticilino-resistentes predominaron en muestras de heridas (46%), hemocultivo (29%) y punta de catéter (5%); gran parte de ellos procedía de UCI neonatal (25%), médica (21%) y cirugía (16%). Conclusiones:S. aureus y SCN se aislaron con mayor frecuencia en hemocultivos y heridas procedentes de UCI neonatal y cirugía. Los fenotipos de resistencia predominantes fueron para penicilina y oxacilina.

The Staphylococcusspp. they can cause a wide range of infections systemic and located in community and hospital patients. Its high pathogenicity and growing resistance to multiple antimicrobials including methicillin, causes high morbiditymortality rates, causing a high epidemiological impact. Objective: to determine the phenotypic profile of resistance to different antimicrobials in strains of the genus Staphylococcus spp. Materials and methods: collected 75 strains and determined them susceptibility to different antibiotics by the Kirby-Bauer method. The production of betalactamase check using the nitrocefin test. (Resistance to Methicillin in S. aureus was conducted using Mueller Hinton with 4% NaCl and oxacillin 6 µg/mL). Inducible clindamycin resistance tamizo by D-Test test. Results: they were isolated by 38% of staphylococcus coagulase negative (SNA) and 62% of S. aureus. 53% were penicillin resistant staphylococci: S. aureus with 58% and 42% SNA. 47% of the strains showed resistance to methicillin: S. aureus with 61% and SNA with 39%. A strain of S. aureus showed inducible resistance to clindamycin (1.33%). Coagulase negative staphylococci were isolated mostly from blood samples (31%), blood (29%), tip of catheter (5%) and came mostly from neonatal ICU (25%), medical (21%) and surgery (16%). Conclusions: S. aureus and SNA were isolated with greater frequency in blood and wounds from surgery and neonatal ICU. The predominant resistance phenotypes were penicillin and oxacillin.

Os Staphylococcus spp. causam uma ampla série de infecções sistemáticas e localizadas em pacientes hospitalizados e comunitários. Sua alta patogenicidade e sua crescente resistência a múltiplos antimicrobianos, entre eles a meticilina, causam taxas elevadas de morbimortalidade ocasionando um alto impacto epidemiológico. Objetivo: determinar o perfil fenotípico de resistência a diferentes antimicrobianos em cepas do gênero Staphylococcus spp. Materiais e métodos: se recoletaram setenta e cinco cepas, e determinou-se suscetibilidade aos diferentes antibióticos pelo método de Kirby Bauer. A produção de beta-lactamase verificou-se mediante a prova do nitrocefin. A resistência à meticilina en S. aureus realizou-se usando Mueller Hinton com 4% de NaCl e oxacilina 6 µg/mL. A resistência induzível a clindamicina se tamisou mediante a prova do D-Test. Resultados: se isolo um 38% de estafilococos coagulase negativa (SCN) e um 62% de S. aureus. Um 53% dos estafilococos foram resistentes à penicilina: S. aureus com 58% e SCN 42%; um 47% das cepas apresentaram resistência à meticilina: S. aureus com um 61% e SCN com um 39%; uma cepa de S. aureus mostrou resistência induzível á clindamicina (1,33%). Em sua maioria, os estafilococos coagulase negativa foram isolados a partir de amostras de hemoculturas (31%) e os estafilococos meticilino-resistentes predominaram em amostras de feridas (46%), hemocultura (29%) e ponta de cateter (5%); grande parte deles procedia de UCI neonatal (25%), médica (21%) e cirurgia (16%). Conclusões: S. aureus y SCN se isolaram com maior frequência em hemoculturas e feridas procedentes de UCI neonatal e cirurgia. Os fenótipos de resistência predominantes foram para penicilina e oxacilina.

New 3,4-seco-ent-kaurene dimers from Croton micans.

From the stems of Croton micans Sw., five new 3,4-seco-ent-kaurene dimers: micansinoic acid (1), isomicansinoic acid (2), and the dimethyl (3), monomethyl (4) and monoethyl ester (5) of micansinoic acid were isolated. The structures of the new compounds were elucidated by spectroscopic data interpretation, mainly 1D and 2D NMR experiments and MS. These compounds are the first 3,4-seco-ent-kaurene dimers from a Croton species.

Cytotoxic activity of seco-entkaurenes from Croton caracasana on human cancer cell lines.

In the course of searching for bioactive compounds from Croton species from Venezuela, two seco-entkaurenes isolated from flowers of Croton caracasana were evaluated in vitro for their effect on cell viability by the standard MTT assay in nine human cancer cell lines of different origins and one primary culture. Both compounds induced cytotoxicity in the range of 2 to 25 microM for caracasine and 0.8 to 12 microM for caracasine acid. However, for the normal fibroblasts and the cell lines, HeLa, MCF-7, PC-3, LoVo, X-17, Jurkat E6.1 and Jurkat JCaM1.6, the IC50 values of caracasine acid were lower than their counterparts. Interestingly, no differences in IC50 were recorded for the leukemic cell lines U937 and K562. It can be concluded that the acid moiety in the structure enhances the cytotoxic effect of caracasine by a pathway which seems not to be activated in the leukemic cell lines tested.