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.

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.

Avaliação de genótipos de cafeeiros Arabica e Robusta no estado do Acre / Evaluation of Arabica and Robusta coffee genotypes in the state of Acre

Conduziu-se este trabalho, com o objetivo de introduzir e avaliar 40 genótipos de cafeeiros das espécies Coffea arabica e Coffea canephora nas condições edafoclimáticas do Estado do Acre, visando disponibilizar aos cafeicultores acreanos, cultivares com melhor potencial produtivo. Da espécie C. arabica foram avaliados genótipos das cultivares Icatu, Bourbon, Mundo Novo, Catuaí, Obatã e Catimor. Da espécie C. canephora foram avaliadas as cultivares Conilon e Robusta, caracterizadas como Grupo Robusta. Os genótipos utilizados foram provenientes do Instituto Agronômico de Campinas (IAC) e da Embrapa Rondônia. O experimento foi conduzido no Campo Experimental da Embrapa Acre, Rio Branco, AC, no período de 1995 a 2004. O delineamento experimental foi em blocos casualizados com cinco repetições. As características avaliadas foram: produtividade, altura, diâmetro da copa e vigor. Da espécie C. arabica, grupo Icatu, destacou-se Icatu-PR-182039-1(IAC H 4782-7-788) com produtividade média de café 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 Catuaí os melhores genótipos foram Obatã IAC 4275, Obatã IAC 1169 e Catimor IAC 4466 com produtividade média de café beneficiado de 49, 45 e 37 sacas por hectare respectivamente. Na espécie C. canephora foram avaliados 8 genótipos das cultivares Conilon e Robusta e quanto à produtividade não houve diferença estatística, observou-se incremento de 7 sacas/ha para a variedade Conilon IAC 66-3 quando comparado ao Conilon plantado na região. Nesta espécie os genótipos apresentaram sintomas de deficiência hídrica na época seca (julho/agosto).

This work aimed to introduce and evaluate 40 coffee genotypes of Coffea arabica e Coffea canephora species in soil and weather conditions of Acre and had as main goal to provide cultivars to coffee producers with better potential of production. It was evaluated the genotypes Icatu, Bourbon, Mundo Novo, Catuaí, Obatã e Catimor from Coffea arabica species and genotypes Conilon and Robusta from Coffea canephora species. The genotypes were originated from Instituto Agronômico de Campinas (IAC) and Embrapa Rondônia. The study was carried out in the experimental field of Embrapa Acre, Rio Branco, AC from 1995 to 2004 following a randomized block design, with 5 replicates. One studied characteristics such as yield, height, plant diameter and vigor. The best genotype of Coffea arabica species, Icatu group, showed to be the Icatu-PR-182039-1(IAC H 4782-7-788), which yielded 34 sacks/ha of clean coffee; right after came Icatu IAC-4041, Icatu IAC-2945, Icatu IAC-2944-MT, Icatu IAC- 4040 and Icatu IAC-4046 with mean yeld from 20 to 26 sacks. For Catuai group, the best genotypes were Obatã IAC 4275, Obatã IAC 1169 e Catimor IAC 4466 with mean yield of 49, 45 e 37 sacks per hectare of clean coffee respectively. In the Canephora species were evaluated eigth genotypes of conilon and robusta which did not show significant difference among them related to yield, although it was observed a difference of 7 sacks/ha more for the gentotypes IAC 66-3 when compared to the local Conilon. In this group it was noted drought stress during the dry season (July/August) for all the genotypes.