Desenvolvimento e caracterização de cápsulas probióticas contendo Lactobacillus Rhamnosus

A encapsulação é uma técnica que pode ser empregada para a proteção de probióticos, conferindo-os resistência ao ambiente ácido do trato gastrintestinal, bem como viabilizando sua aplicação em produtos lácteos fermentados. O presente estudo teve como objetivo avaliar as melhores concentrações de encapsulamento de L. rhamnosus utilizando alginato de sódio, pectina e gelatina. Foram realizados dois planejamentos experimentais para cápsulas contendo alginato e gelatina e pectina e gelatina. As variáveis investigadas foram as concentrações dos polímeros e a variável resposta foi a concentração de células viáveis nas cápsulas. A maior concentração de células viáveis (4,2 x 109 UFC/g) foi obtida para as concentrações de 1 % de alginato e 0,1 % de gelatina, sendo que a concentração de alginato foi a variável que influenciou de forma mais significativa a variável resposta, atingindo um efeito estimado negativo de -4,59. A avaliação estatística dos resultados das microcápsulas obtidas com pectina não foi satisfatória. Os resultados do Infravermelho mostraram que as três amostras analisadas continham o alginato, estas apresentaram picos muito próximos de 3400 cm-1 para 3454 cm-1 em relação ao grupo O-H. Nos espectros das microcápsulas observamos um pico com intensidade entre 1637 cm-1 e 1639 cm-1 comprovando a presença do grupo funcional –CONH² que está presente na gelatina, visto que o alginato puro não apresentou esse pico. A análise térmica do material indicou uma temperatura de transição vítrea (Tg) acima da temperatura de armazenamento das microcápsulas, o que garante a cristalização das microcápsulas. Após 120 dias de armazenamento sob refrigeração as cápsulas atingiram a concentração de 105UFC/ml, sendo ainda adequadas para a sua incorporação em alimentos. Com relação a incorporação das microcapsulas e das células livres no fermentado de leite, as células livres obtido pela adição de de L. rhamnosus ATCC 7469, apresentou a contagem mínima necessária para um produto ser considerado probiótico. As microcápsulas produzidas através da técnica de extrusão com alginato como agente encapsulante foram adequadas para a microencapsulação destes probióticos, enquanto que as microcápsulas obtidas com pectina não foram satisfatórias.Encapsulation is a technique that can be used for the protection of probiotics, conferring resistance to the acidic environment of the gastrointestinal tract allowing its use in fermented milk products. The present study had as objective evaluates the best encapsulation concentrations of L. rhamnosus using alginate of sodium, pectin and gelatin. Two experimental designs were conducted to capsules containing alginate and gelatin and pectin and gelatin. The variables investigated were concentrations of polymer and the dependent variable was the concentration of viable cells in the capsules. The highest concentration of viable cells (4.2 x 109 CFU/g) was achieved for concentrations of 1 % alginate and 0.1 % gelatin, whereas the concentration of alginate was variable that affected the response variable most significantly, reaching a negative estimated effect of -4.59. Statistical evaluation of the results obtained with microcapsules of pectin was not satisfactory. Results of IR spectra show that the three samples that were analyzed contain the alginate. The spectra shows peaks due to O−H group in the region of 3400−3454 cm−1. The spectra of Microcapsules shows a peak between 1637 cm−1 and 1639 cm−1 confirming the presence of the functional group –CONH2 that is present in the gelatin, whereas pure alginate does not show this peak. Thermal analysis of the material indicates a glass transition temperature (Tg) above the storage temperature of the microcapsules, which ensures the crystallization of the microcapsules. After 120 days of storage under refrigeration capsules have reached the concentration of 105UFC/mL, still being suitable for incorporation in food. Regarding the incorporation of the microcapsules and the free cells in the fermented milk, the free cells obtained by addition of L. rhamnosus ATCC 7469, presented the minimum score needed for a product to be considered probiotic. The microcapsules produced by the extrusion technique with alginate as encapsulating agents were suitable for microencapsulation of these probiotics, while microcapsules obtained were not satisfactory with pectin

Alkyl and Aryl Derivatives Based on p-Coumaric Acid Modification and Inhibitory Action against Leishmania braziliensis and Plasmodium falciparum

In low-income populations, neglected diseases are the principal cause of mortality. Of these, leishmaniasis and malaria, being parasitic, protozoan infections, affect millions of people worldwide and are creating a public health problem. The present work evaluates the leishmanicidal and antiplasmodial action of a series of twelve p-coumaric acid derivatives. Of the tested derivatives, eight presented antiparasitic activities 1–3, 8–12. The hexyl p-coumarate derivative (9) (4.14 ± 0.55 μg/mL; selectivity index (SI) = 2.72) showed the highest leishmanicidal potency against the Leishmania braziliensis amastigote form. The results of the molecular docking study suggest that this compound inhibits aldehyde dehydrogenase (ALDH), mitogen-activated kinase protein (MPK4), and DNA topoisomerase 2 (TOP2), all of which are key enzymes in the development of Leishmania braziliensis. The data indicate that these enzymes interact via Van der Waals bonds, hydrophobic interactions, and hydrogen bonds with phenolic and aliphatic parts of this same compound. Of the other compounds analyzed, methyl p-coumarate (64.59 ± 2.89 μg/mL; IS = 0.1) demonstrated bioactivity against Plasmodium falciparum. The study reveals that esters presenting a p-coumarate substructure are promising for use in synthesis of derivatives with good antiparasitic profiles

Trypanocidal Mechanism of Action and in silico Studies of p-Coumaric Acid Derivatives

Trypanosoma species are responsible for chronic and systemic infections in millions of people around the world, compromising life quality, and family and government budgets. This group of diseases is classified as neglected and causes thousands of deaths each year. In the present study, the trypanocidal effect of a set of 12 ester derivatives of the p-coumaric acid was tested. Of the test derivatives, pentyl p-coumarate (7) (5.16 ± 1.28 μM; 61.63 ± 28.59 μM) presented the best respective trypanocidal activities against both epimastigote and trypomastigote forms. Flow cytometry analysis revealed an increase in the percentage of 7-AAD labeled cells, an increase in reactive oxygen species, and a loss of mitochondrial membrane potential; indicating cell death by necrosis. This mechanism was confirmed by scanning electron microscopy, noting the loss of cellular integrity. Molecular docking data indicated that of the chemical compounds tested, compound 7 potentially acts through two mechanisms of action, whether by links with aldo-keto reductases (AKR) or by comprising cruzain (CZ) which is one of the key Trypanosoma cruzi development enzymes. The results indicate that for both enzymes, van der Waals interactions between ligand and receptors favor binding and hydrophobic interactions with the phenolic and aliphatic parts of the ligand. The study demonstrates that p-coumarate derivatives are promising molecules for developing new prototypes with antiprotozoal activity