2 research outputs found
Brazilian Morus nigra
Morus nigra has been used popularly for several proposes, including diabetic. In an attempt to support medicinal value, the acute hypoglycemic, hypolipidemic, and antioxidant effects of the ethanolic extract of Morus nigra (EEMn 200 or 400 mg/kg b.w.) were evaluated in normal and alloxan-induced diabetic treated for 14 days. Serum biochemical and antioxidant analysis were performed at the end of experiment. Oral glucose tolerance test was performed at 10th and 15th days. Chromatographic analysis by HPLC-DAD of EEMn was performed. Insulin was used as positive control to glycemic metabolism as well as fenofibrate to lipid metabolism. EEMn (400 mg/kg/day) reduced fasting and postprandial glycaemia, improved oral glucose tolerance, and reduced lipolysis and proteolysis in diabetic rats. EEMn decreased the blood levels of total cholesterol and increased HDL level when compared to the diabetic control rats. At higher levels, EEMn reduced triglycerides and VLDL levels in diabetic rats. Also, EEMn reduced malondialdehyde and increased the reduced glutathione levels in liver of diabetic rats. Chromatographic analysis identified the presence of the flavonoids rutin, isoquercetin, and kaempferitrin. Acute EEMn treatment reduced hyperglycemia, improved oral glucose tolerance, and minimized dyslipidemia and oxidative stress leading to a reduction in atherogenic index in alloxan-induced diabetic rats
Study of the sucrose catabolism in Burkholderia sacchari, a microbial cell factory
Este trabalho está focado no entendimento do catabolismo da sacarose por Burkholderia sacchari (sinon. Paraburkholderia sacchari), uma fábrica de celular promissora para a produção de polímeros biodegradáveis pertencentes à família dos polihidroxialcanoatos (PHA). Seu espectro de utilização de substratos para produzir PHA é bastante amplo, comparado com espécies classicamente estudadas na área e o uso de sacarose, abundante no país, confere potencial a essa bactéria ser o chassi preferencial para a produção de PHA e outros bioprodutos. Entretanto, os mecanismos de catabolismo de sacarose necessitam ser elucidados para entender a sua rede metabólica e propor melhoramentos ou mesmo capacitar outras linhagens de interesse no consumo de sacarose. Para isso, neste trabalho, o genoma completo de P. sacchari, restritamente disponível no servidor de Anotação Rápida que usa Tecnologia de Subsistema (RAST), foi analisado para a presença de genes relacionados à hidrólise de sacarose (invertase) e fosforilação de sacarose (sacarose-6-fosfato-hidrolase). Em seguida, as semelhanças encontradas tiveram anotação confirmada usando a Ferramenta Básica de Pesquisa de Alinhamento Local (BLAST) ao mesmo tempo que foram comparadas com outras espécies bacterianas e dentro de Paraburkholderia/Burkholderia spp. Comparou-se ainda o crescimento de P. sacchari em cultivos em frascos agitados, oferecendo-se sacarose ou uma mistura de glicose e frutose para verificar o perfil do consumo desses açúcares. Os resultados in silico indicaram um cluster putativo de sacarose que pode codificar genes para um tipo de hidrolase externa que pode ser uma levansucrase (EC 2.4.1.10, pode-se observar filogeneticamente que sequências de aminoácidos levansucrases/GH68 em Paraburkholderia/Burkholderia spp estão relacionados. O sobrenadante livre de células obtido de uma cultura celular crescida em sacarose apresentou atividade hidrolítica sobre a sacarose, o que corrobora com a hipótese de ser uma enzima de ação extracelular. Os resultados de comparação dos cultivos de P. sacchari em frascos agitados, frente a sacarose ou glicose + frutose, mostraram curvas de crescimento semelhantes nas condições testadas tendo sido observados valores das velocidades específicas máximas de crescimento de 0,36 ± 0,005 h-1 em sacarose e 0,33 ± 0,005 h-1 na mistura de glicose e frutose. Os resultados indicam que, em P. sacchari, o catabolismo da sacarose envolve a hidrólise externa do açúcar, que pode ser realizada por uma putativa levansucrase. Os açúcares resultantes da hidrólise provavelmente são internalizados por um sistema fosfotransferase (PTS) específico para glicose e frutose. Neste trabalho, os resultados corroboram evidências de que em P. sacchari, a hidrólise externa da sacarose é realizada extracelularmente. Para continuidade dos estudos, foi construída uma biblioteca de 1070 mutantes utilizando o transposon miniTn5 tendo sido avaliados e selecionados fenotipicamente 9 mutantes sac-. Os resultados mostram que os mutantes apresentaram deficiências no crescimento em sacarose e capazes de consumir glicose e frutose, assim a busca de mutantes deficientes em consumir glicose e especialmente frutose, deve ser ampliada ou a inativação dos genes identificados acima deve ser obtida para confirmar o seu papel na rota de catabolismo proposta.This work is focused on the understanding of sucrose catabolism by Burlkolderia sacchari (sinon. Paraburkholderia sacchari), a promising cell factory for the production of biodegradable polymers belonging to the polyhydroxyalkanoate (PHA) family. Its spectrum of use of substrates to produce PHA is quite broad, compared to species classically studied in the area and the use of sucrose, abundant in the country, gives the potential for this bacterium to be the preferred chassis for the production of PHA and other bioproducts. However, the mechanisms of sucrose catabolism need to be elucidated to understand its metabolic network and propose improvements or even enable other strains of interest in sucrose consumption. Therefore, in this work, the complete genome of P. sacchari, restricted available on the Rapid Annotation Server using Subsystem Technology (RAST), was studied for the presence of genes related to sucrose hydrolysis (invertase) and sucrose phosphorylation (sucrose-6-phosphate hydrolase). Then, the similarities found had annotation confirmed using the Basic Local Alignment Research Tool (BLAST) while they were compared with other bacterial species and within Paraburkholderia/Burkholderia spp. The growth of P. sacchari was also compared in cultures in flasks of sucrose or a mixture of glucose and fructose to verify their consumption profile. The in silico results indicated a putative sucrose cluster that can encode genes for a type of external hydrolase that can be a levansucrase (EC 2.4.1.10), it can be phylogenetically observed that levansucrase amino acid sequences /GH68 in Paraburkholderia/Burkholderia spp are related. The cell-free supernatant obtained from a cell culture grown in sucrose showed hydrolytic activity on sucrose, which corroborates the hypothesis that it is an enzyme with extracellular action. The results of comparison of P. sacchari cultures in shake flasks, against sucrose or glucose + fructose, showed similar growth curves in the tested conditions, having been observed values of maximum specific growth rates of 0.36 ± 0.005 h-1 in sucrose and 0.33 ± 0.005h-1 in the glucose and fructose mixture. The results indicate that, in P. sacchari, sucrose catabolism involves the external hydrolysis of the sugar, which can be carried out by a putative levansucrase. The sugars resulting from hydrolysis are likely to be internalized by a phosphotransferase system (PTS) specific for glucose and fructose. In this work, the results corroborate evidence that in P. sacchari, the external hydrolysis of sucrose is carried out extracellularly. For the continuity of the studies, a library of 1070 mutants was built using the miniTn5 transposon, having been evaluated and phenotypically selected 9 suc- mutants. The results presented that the mutants presented deficiencies in growth in sucrose are capable of consuming glucose and fructose, the search for mutants deficient in consuming glucose and especially fructose, must be expanded or the inactivation of the genes identified above must be obtained to confirm the its role in the proposed catabolism route