Rita de Cássia Alves Pereira

In vitro cultivated Uncaria tomentosa and Uncaria guianensis with determination of the pentacyclic oxindole alkaloid contents and profiles

Uncaria tomentosa (Willd.) DC. and Uncaria guianensis (Aubl.) Gmel., commercially known as cats claw, are large woody vines native of the Amazon and Central America rainforests. These Rubiaceae species face nowadays an imminent risk of extinction due to indiscriminate harvesting in the wild as well as to increasing deforestation of their natural habitat. This work describes in vitro cultivation methods for both species with determination, by HPLC, of the pentacyclic oxindole alkaloid contents and profiles of the plant material. The results have proved that the methods we developed were able to produce plants with alkaloid profiles and contents similar to the wild and in vivo cultivated species, and with the additional advantage of producing suitable young plants in a shorter period of time. The data showed that the in vitro technique can be a feasible tool for the growth of the species, and may thus be important for their commercialization and for their conservation as a forest resource.

Germinação, avaliação do ácido giberélico e posição do explante no alongamento in vitro de Uncaria guianensis (AUBLET) Gmelin Rubiaceae (UNHA-DE-GATO)

Na Amazonia existe uma diversidade vegetal, onde se encontram muitas plantas com propriedades medicinais e, que durante milenios sao utilizadas pelas comunidades nativas. Uma dessas plantas e a unha-de-gato (Uncaria guianensis), cujo valor medicinal se atribui a efeitos imuno-estimulantes, anti-inflamatorio e inibidores de crescimento de celulas cancerigenas. Atualmente, a especie vem sendo submetida a uma extracao indiscriminada e intensiva, podendo leva-la a sua extincao. A micropropagacao permite solucionar problemas dessa natureza. Objetivou-se com este trabalho identificar um protocolo de propagacao in vitro desta especie. O melhor meio para germinacao dos embrioes foi ¼ de MS independente da presenca ou nao de sacarose. A posicao de inoculacao do explante da especie Uncaria guianensis demonstrou exercer influencia no numero medio de brotacoes/explante original, assim como no numero de gemas iniciais. Presenca ou ausencia de acido giberelico nao exerceu efeito nesta caracteristica, exceto quando explantes com uma unica gema foram inoculados na horizontal.

The antimicrobial efficacy of Lippia alba essential oil and its interaction with food ingredients

The objective of this study was to evaluate the antimicrobial potential of Lippia alba essential oil (EOLa) and to investigate the effect of food ingredients on its efficacy. The antimicrobial potential of the oil was determined by the presence or absence of inhibition zones, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Escherichia coli, Listeria innocua, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella choleraesuis and Staphylococcus aureus. The effect of food ingredients and the pH on the antimicrobial efficacy of oil was assessed by monitoring the maximum growth rate of Listeria monocytogenes in model media. The model media included potato starch (0, 1, 5 or 10%), beef extract (1, 5, 3, 6 or 12%), sunflower oil (0, 5 or 10%) and TSB broth at pH levels of 4, 5, 6 or 7. The EOLa showed efficacy at all concentrations (50%, 25%, 6.25%, 3%, 1.5%, 0.8%, 0.4% and 0.2%) evaluated, against all bacterial species, Gram-positive and Gram-negative. The antimicrobial efficacy of EO was found to be a function of ingredient manipulation. Proteins and lipids had a negative impact on the oil effectiveness, indicating the protective action of both on the microbial specie tested. On the contrary, at the highest concentration of starch (10%), the lower rate growth of L. monocytogenes was detected, therefore indicating a positive effect of carbohydrates on the oil effectivenes. Regarding the pH, the studies showed that the rate of microbial growth increased with increasing pH. It was concluded that the use of EOLa is more effective control pathogenic and spoilage bacteria when applied to starchy foods under an acidic pH.

Seasonal variability of the antimicrobial activity of the essential oil of Lippia alba

Lippia alba e um arbusto da familia Verbenaceae, popularmente conhecida como erva-cidreira. Seu oleo essencial e citado com amplo espectro de atividade antimicrobiana, cuja eficacia varia em funcao da sua composicao, que sofre influencia de fatores bioticos e abioticos. O presente trabalho teve como objetivo, avaliar a eficacia antimicrobiana do oleo de folhas de L. alba, coletadas nas diferentes estacoes do ano, frente a microrganismos de importância em alimentos. O oleo, obtido por hidrodestilacao, foi testado contra culturas padroes de Pseudomona aeruginosa, Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes e Listeria innocua, utilizando as tecnicas de difusao em agar. Observou-se uma grande influencia das diferentes epocas de coleta na eficiencia do oleo, que variou em funcao de cada especie microbiana. No periodo dezembro - fevereiro, a melhor resposta foi frente a S. aureus. Para L. monocytogenes a maior eficacia do oleo ocorreu no periodo junho - agosto, enquanto que para L. innocua o oleo apresentou a mesma resposta em tres periodos do ano, diferenciando apenas no periodo compreendido entre marco e maio. A correlacao dos dados meteorologicos do ano de 2010 permite aferir, que as caracteristicas tipicas do periodo dezembro a fevereiro no municipio de Paraipaba-CE (altas temperaturas, longos periodos de insolacao e baixo indice de precipitacao pluiometrica) favoreceram a acao do oleo frente S. aureus. No periodo de junho a agosto, por sua vez, as condicoes da estacao potencializaram a acao do oleo contra L. monocytogenes e L. innocua.

Avaliação de genótipos de cafeeiros Arabica e Robusta no estado do Acre

Conduziu-se este trabalho, com o objetivo de introduzir e avaliar 40 genotipos de cafeeiros das especies Coffea arabica e Coffea canephora nas condicoes edafoclimaticas do Estado do Acre, visando disponibilizar aos cafeicultores acreanos, cultivares com melhor potencial produtivo. Da especie C. arabica foram avaliados genotipos das cultivares Icatu, Bourbon, Mundo Novo, Catuai, Obata e Catimor. Da especie C. canephora foram avaliadas as cultivares Conilon e Robusta, caracterizadas como Grupo Robusta. Os genotipos utilizados foram provenientes do Instituto Agronomico de Campinas (IAC) e da Embrapa Rondonia. O experimento foi conduzido no Campo Experimental da Embrapa Acre, Rio Branco, AC, no periodo de 1995 a 2004. O delineamento experimental foi em blocos casualizados com cinco repeticoes. As caracteristicas avaliadas foram: produtividade, altura, diâmetro da copa e vigor. Da especie C. arabica, grupo Icatu, destacou-se Icatu-PR-182039-1(IAC H 4782-7-788) com produtividade media de cafe beneficiado de 34 sc/ ha, Icatu IAC-4041; Icatu IAC-2945; Icatu IAC-2944-MT; Icatu IAC-4040 e Icatu IAC-4046 com produtividade variando de 20 a 26 sacas. Para o grupo Catuai os melhores genotipos foram Obata IAC 4275, Obata IAC 1169 e Catimor IAC 4466 com produtividade media de cafe beneficiado de 49, 45 e 37 sacas por hectare respectivamente. Na especie C. canephora foram avaliados 8 genotipos das cultivares Conilon e Robusta e quanto a produtividade nao houve diferenca estatistica, observou-se incremento de 7 sacas/ha para a variedade Conilon IAC 66-3 quando comparado ao Conilon plantado na regiao. Nesta especie os genotipos apresentaram sintomas de deficiencia hidrica na epoca seca (julho/agosto).

Drying kinetics and effect of air-drying temperature on chemical composition of Phyllanthus amarus and Phyllanthus niruri

ABSTRACT In this study, the drying kinetics of Phyllanthus amarus and Phyllanthus niruri were investigated experimentally in an air-drying oven as a function of drying temperature (50, 60, and 70°C). The effects of the air-drying temperature on the phenolic content and the LC–MS profile were also studied. Increases in air-drying temperature reduced the drying time and increased the effective moisture diffusivity. An Arrhenius relationship with activation energy values of 22.828 and 43.129 kJ/mol for P. niruri and P.amarus, respectively, expressed the effect of temperature on the diffusivity. Air drying at 70°C increased the availability of some phenolic compounds. However, the higher temperature negatively affected some sensitive components.

Decrease in Dengue virus-2 infection and reduction of cytokine/chemokine production by Uncaria guianensis in human hepatocyte cell line Huh-7

ABSTRACT BACKGROUND Dengue fever may present hemorrhages and cavitary effusions as result of exacerbated immune responses. We investigated hydro-alcoholic extracts from leaves (UGL) and bark (UGB) of the medicinal species Uncaria guinanensis with respect to antiviral effects in Dengue virus (DENV) infection and in immunological parameters associated with in vivo physiopathological features. METHODS Chemical profiles from UGB or UGL were compared in thin layer chromatography and 1H nuclear magnetic resonance using flavonoid compounds and a pentacyclic oxindole alkaloid-enriched fraction as references. DENV-2-infected hepatocytes (Huh-7) were treated with extracts. Cell viability, DENV antigens and immunological factors were detected by enzyme-linked immunosorbent assay (ELISA) or flow cytometry. FINDINGS The UGL mainly differed from UGB by selectively containing the flavonoid kaempferitrin. UGB and UGL improved hepatocyte viability. Both extracts reduced intracellular viral antigen and inhibited the secretion of viral non-structural protein (NS1), which is indicative of viral replication. Reduction in secretion of macrophage migration inhibitory factor was achieved by UGB, of interleukin-6 by UGL, and of interleukin-8 by both UGB and UGL. MAIN CONCLUSIONS The U. guianensis extracts presented, antiviral and immunomodulatory effects for DENV and possibly a hepatocyte-protective activity. Further studies may be performed to consider these products as potential candidates for the development of an herbal product for the future treatment of dengue.

Piperamides from Piper ottonoides by NMR and GC-MS Based Mixture Analysis

The species Piper ottonoides Yuncker (Piperaceae), known as “joao-brandim”, is a shrub that occurs in the Brazilian Amazon rainforest. Its roots and leaves are used in traditional medicine as local anesthetic to treat toothache and sore throat. In this study, the structural characterization in mixture of isobutyl amides present in semi-purified fractions from fruits, leaves, stems and roots of P. ottonoides was achieved by employing gas chromatography-mass spectrometry (GC-MS) and a combination of nuclear magnetic resonance (NMR) techniques (1H, 1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC, TOCSY and 1H-1H J-RES). The MS fragmentation patterns and the NMR chemical shifts, multiplicities, coupling constants and the signal correlations in the two-dimensional spectra were carefully analyzed also taking into account some key elements of differentiation among the compounds. The data set allowed identifying unequivocally the new amide N-isobutyl-7-(4’- methoxyphenyl)-2E,4E-heptadienamide, which we named ottonoidenamide as well as piperovatine and chingchengenamide A in all parts of the plant, the additional presence of pipercallosine and pipercallosidine in roots and of dihydropiperlonguminine in fruits and leaves. The presence of piperovatine and pipercallosine in P. ottonoides should be associated to its traditional use.