14 research outputs found

    Cytotoxic lipidic α-amino acids from the zoanthid Protopalythoa variabilis from the Northeastern coast of Brazil

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    Two lipidic α-amino acids 1a and 1b were isolated from the zoanthid Protopalythoa variabilis using a bioguided fractionation for cytotoxic activity. The structures of the metabolites were determined by spectroscopic methods, including NMR (nuclear magnetic resonance) ¹H e 13C, IR (infrared) and high resolution mass spectrometry (positive mode). The cytotoxic activity of the crude extract, as well as of the mixture of 1a and 1b were measured in vitro using the MTT assay for four human tumor cell lines. This finding has important biological and chemical implications for this type of compound. This is the first report of lipidic α-amino acids from natural sources, as well as of their cytotoxic activity.Dois α-aminoácidos lipídicos 1a e 1b foram isolados do zoantídeo Protopalythoa variabilis através de fracionamento guiado pela atividade citotóxica. As estruturas foram determinadas por diferentes métodos espectroscópicos, tais como, RMN (ressonância magnética nuclear) ¹H e 13C, IV (infravermelho) e espectrometria de massa de alta resolução (modo positivo). A atividade citotóxica dos extratos, das frações e 1a/1b foi avaliada in vitro através do teste do MTT contra quatro linhagens de células tumorais. Este achado tem implicações biológicas e químicas importantes para essa classe de compostos. Este é o primeiro relato de α-aminoácidos lipídicos a partir de uma fonte natural, bem como de sua atividade citotóxica.CNPqFINEPInstitute Claude Bernar

    Constituintes químicos voláteis e não-voláteis de Cochlospermum vitifolium (Willdenow) Sprengel Volatile and non-volatile chemical constituents of Cochlospermum vitifolium (Willdenow) Sprengel

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    <abstract language="eng">The essential oils from leaves, root bark and root wood of Cochlospermum vitifolium were investigated for the first time. The oils were obtained by hydrodistillation and analyzed by GC/MS. The main volatile constituents were beta-caryophyllene (8.2 - 46.5%), beta-bisabolene (11.5 - 29.3%), gamma-muurolene (28.4%), alpha-humulene (26.0%), 1-hydroxy-3-hexadecanone (16.2 - 19.5%) and beta-pinene (10.6%). Phytochemical analysis of the root bark and root wood extracts yielded excelsin, pinoresinol, narigenin, aromadendrin, galic acid and a triacylbenzene, along with beta-sitosterol and stigmasterol and their D-glucosides. The structures of all compounds were determined by analyses of the spectroscopic data (NMR and MS), and comparison with the literature

    H and 13 C NMR Application to Structure Elucidation of Prenylated Naphthoquinone Dimers from Lippia microphylla

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    Resumo: Duas naftoquinonas diméricas preniladas, uma conhecida e outra inédita, foram isoladas das raízes de Lippia microphylla. Suas estruturas foram determinadas por métodos espectroscópicos (IV and EM) incluindo detalhada análise de RMN 1D e 2D (BBHD, DEPT, HMQC, HMBC e NOESY). A correlação inequívoca de todos os dados de RMN com todos os átomos de hidrogênio e carbono da estrutura proposta para o novo composto é sugerida

    Pro-apoptotic activity of lipidic α-amino acids isolated from Protopalythoa variabilis

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    Lipidic alpha-amino acids (LAAs) have been described as non-natural amino acids with long saturated or unsaturated aliphatic chains. In the continuing prospect to discover anticancer agents from marine sources, we have obtained a mixture of two cytotoxic LAAs (1a and 1b) from the zoanthid Protopalythoa variabilis. The anti-proliferative potential of 14 synthetic LAAs and 1a/1b were evaluated on four tumor cell lines (HCT-8, SF-295, MDA-MB-435, and HL-60). Five of the synthetic LAAs showed high percentage of tumor cell inhibition, while 1a/1b completely inhibited tumor cell growth. Additionally, apoptotic effects of 1a/1b were studied on HL-60 cell line. 1a/1b-treated cells showed apoptosis morphology, loss of mitochondrial potential, and DNA fragmentation. (C) 2010 Elsevier Ltd. All rights reserved

    Efeito da toxicidade da fração da Auxemma oncocalyx e seu princípio ativo oncocalyxona A no cultivo in vitro de folículos secundários e na maturação in vitro de oócitos de caprinos

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    Crude extract of the heartwood of Auxemma oncocalyx (A. oncocalyx) and its main component i.e., Oncocalyxone A (onco A), have elevated antioxidant and anti-tumoral activity, but studies on the action of these drugs regarding folliculogenesis are lacking. The aim of this study was to evaluate the effect of A. oncocalyx and onco A on the in vitro culture of isolated secondary follicles and on the in vitro maturation of oocytes from caprine antral follicles grown in vivo. Isolated secondary follicles were randomly distributed in six groups; the non-cultured control was immediately fixed upon isolation. The remaining follicles were cultured for 7 days in ?-MEM+ alone (control) or supplemented with DMSO, doxorrubicin, A. oncocalyx or onco A. After culture, follicles were evaluated for antrum formation, growth rate, apoptosis (TUNEL) and cellular proliferation (PCNA), as well as gene expression of Bcl2 and Bax. Additionally, cumulus oocyte complexes (COCs) were aspirated and allocated into five treatments for in vitro maturation: control, cultured only in maturation base medium (TCM 199+); or supplemented with DMSO; DXR; A. oncocalyx or onco A. After in vitro maturation, oocyte chromatin configuration and viability were assessed. After 7 days of culture, there was a reduction (P < 0.05) in the percentage of morphologically intact follicles, antrum formation, growth rate and number of PCNA positive granulosa cells in DXR treatment compared to the other treatments. In the DXR treatment a higher percentage (P < 0.05) of TUNEL positive follicles and higher (P < 0.05) relative BAX:BCL2 mRNA ratio’s were observed. After in vitro maturation of the COCs DXR, A. oncocalyx and onco A treatments had a greater (P < 0.05) percentage of abnormal oocytes and a lower (P < 0.05) percentage of viable oocytes as compared with the control group. However, only DXR and onco A treatments increased (P < 0.05) the percentage of alive oocytes with abnormal chromatin configuration. There were no differences in maturation rates between the control group and DXR, A. oncocalyx and onco A treatments. In conclusion, under our culture conditions, A. oncocalyx and onco A do not exhibit a toxic effect on isolated secondary follicles and on maturation rates of COCs recovered from antral follicles, however, these drugs negatively affected the COCs viability.  Thus, the use of culture biotechnologies as an in vitro secondary follicle culture and in vitro oocyte maturation toxicity testing are appropriated methods to evaluate the possible effects of drugs in folliculogesis.O extrato da Auxemma oncocalyx (A. oncocalyx) e seu componente, Oncocalyxona A (onco A), possui atividade antitumoral, podendo afetar a fertilidade. Entretanto, estudos sobre a ação dessas substâncias em relação à foliculogênese caprina são desconhecidos. O objetivo desse estudo foi avaliar o efeito da A. oncocalyx e onco A no cultivo in vitro de folículos secundários isolados (Experimento 1) e na maturação in vitro (MIV) de oócitos de folículos antrais caprinos crescidos in vivo (Experimento 2). Folículos secundários isolados foram distribuídos em seis grupos, em que o controle não-cultivado foi imediatamente fixado em paraformaldeído 4%. Os folículos restantes foram cultivados durante 7 dias em ?-MEM+ sozinho (controle) ou suplementado com DMSO, doxorrubicina (DXR), A. oncocalyx ou onco A. Após o cultivo, os folículos foram avaliados quanto à formação de antro, taxa de crescimento, apoptose (TUNEL) e proliferação celular (PCNA), bem como a expressão dos genes BCL2 e BAX. Além disso, os complexos cumulus-oócitos (CCOs) foram aspirados e distribuídos em cinco tratamentos para MIV: o controle em meio de maturação (TCM 199+), e os demais tratamentos suplementados com DMSO, DXR, A. oncocalyx ou onco A. Depois da MIV, a configuração da cromatina e viabilidade oocitária foram avaliadas. Após 7 dias de cultivo, observou-se redução na percentagem de folículos morfologicamente intactos, na formação de antro, na taxa de crescimento e no número de células PCNA positivas (P < 0,05). Depois do cultivo, no tratamento DXR foi observada maior percentagem de folículos TUNEL positivos (P < 0,05) e também aumento na taxa de RNAm BAX: BCL2 (P < 0,05). Após MIV dos CCOs, nos tratamentos com DXR, A. oncocalyx e onco A, observou-se maior (P < 0,05) percentagem de oócitos anormais e menor de oócitos viáveis quando comparados ao grupo controle (P < 0,05). No entanto, apenas nos tratamentos DXR e onco A aumentou a percentagem de oócitos viáveis com configuração da cromatina anormais (P < 0,05). Não houve diferenças nas taxas de maturação entre o grupo controle e os tratamentos DXR, A. oncocalyx e onco A. De acordo com nossas condições de cultivo, pode-se concluir que a A. oncocalyx e onco A não apresentaram efeitos tóxicos sobre folículos secundários isolados e as taxas de maturação dos CCOs recuperados a partir de folículos antrais. No entanto, estas substâncias afetam negativamente a viabilidade oocitária. Assim, o uso de biotecnologias como o cultivo de folículos secundários in vitro e MIV de oócitos para testes de toxicidade são métodos apropriados para avaliar possíveis efeitos das drogas na foliculogênese

    Tyramine exerts hypolipidemic and anti-obesity effects in vivo

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    Obesity and dyslipidemia are conditions often associated with cardiovascular risk, inflammation, oxidative stress, and death. Thus, a new approach has been highlighted to promote research and development of pharmacological tools derived from natural sources. Among the most widely studied groups of substances, polyphenols such as tyramine stand out. This study investigated hypolipidemic and anti-obesity properties of tyramine. Oral toxicity evaluation, models of dyslipidemia and obesity were used. To induce dyslipidemia, Poloxamer-407 (P-407) was administered intraperitoneally. In the hypercholesterolemic and obesity model, specific diet and oral tyramine were provided. After 24h of P-407 administration, tyramine 2 mg/kg (T2) decreased triglycerides (TG) (2057.0 ± 158.5 mg/dL vs. 2838 ± 168.3 mg/dL). After 48h, TG were decreased by T2 (453.0 ± 35.47 vs. 760.2 ± 41.86 mg/dL) and 4 mg/kg (T4) (605.8 ± 26.61 760.2 ± 41.86 mg/dL). T2 reduced total cholesterol (TC) after 24h (309.0 ± 11.17 mg/dL vs. 399.7 ± 15.7 mg/dL); After 48h, 1 mg/kg (T1) (220.5 ± 12.78 mg/dL), T2 (205.8 ± 7.1 mg/dL) and T4 (216.8 ± 12.79 mg/dL), compared to P-407 (275.5 ± 12.1 mg/dL). The treatment decreased thiobarbituric acid reactive substances and nitrite in liver, increased superoxide dismutase, reduced the diet-induced dyslipidemia, decreasing TC around 15%. Tyramine reduced body mass, glucose, and TC after hypercaloric feed. Treatment with 5 mg/L (0.46 ± 0.04 ng/dL) and 10 mg/L (0.44 ± 0.02 ng/dL) reduced plasma insulin (1.18 ± 0.23 ng/dL). Tyramine increased adiponectin at 5 mg/L (1.02 ± 0.02 vs. 0.83 ± 0.02 ng/mL) and 10mg/L (0.96 ± 0.04 ng/mL). In conclusion, tyramine has low toxicity in rodents, has antioxidant effect, reduces plasma triglycerides and cholesterol levels. However, further studies should be conducted in rodents and non-rodents to better understand the pharmacodynamic and pharmacokinetic properties of tyramine
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