Reversible flow of cholesteryl ester between high-density lipoproteins and triacylglycerol-rich particles is modulated by the fatty acid composition and concentration of triacylglycerols

We determined the influence of fasting (FAST) and feeding (FED) on cholesteryl ester (CE) flow between high-density lipoproteins (HDL) and plasma apoB-lipoprotein and triacylglycerol (TG)-rich emulsions (EM) prepared with TG-fatty acids (FAs). TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18% and 14%, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001) and a negative correlation from EM to HDL (r = -041, P = 0.0088). Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7%, 20.7%, and 20%, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7%, 51.2%, and 46.3%, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.

Paradoxical effect of a pequi oil-rich diet on the development of atherosclerosis: balance between antioxidant and hyperlipidemic properties

Pequi is the fruit of Caryocar brasiliense and its oil has a high concentration of monounsaturated and saturated fatty acids, which are anti- and pro-atherogenic agents, respectively, and of carotenoids, which give it antioxidant properties. Our objective was to study the effect of the intake of a cholesterol-rich diet supplemented with pequi oil, compared to the same diet containing soybean oil, on atherosclerosis development, and oxidative stress in atherosclerosis-susceptible LDL receptor-deficient mice (LDLr-/-, C57BL/6-background). Female mice were fed a cholesterol-rich diet containing 7% soybean oil (Soybean group, N = 12) or 7% pequi oil (Pequi group, N = 12) for 6 weeks. The Pequi group presented a more atherogenic lipid profile and more advanced atherosclerotic lesions in the aortic root compared to the Soybean group. However, the Pequi group presented a less advanced lesion in the aorta than the Soybean group and showed lower lipid peroxidation (Soybean group: 50.2 ± 7.1; Pequi group: 30.0 ± 4.8 µmol MDA/mg protein) and anti-oxidized LDL autoantibodies (Soybean group: 35.7 ± 9.4; Pequi group: 15.6 ± 3.7 arbitrary units). Peritoneal macrophages from the Pequi group stimulated with zymosan showed a reduction in the release of reactive oxygen species compared to the Soybean group. Our data suggest that a pequi oil-rich diet slows atherogenesis in the initial stages, possibly due to its antioxidant activity. However, the increase of serum cholesterol induces a more prominent LDL migration toward the intimae of arteries, increasing the advanced atherosclerotic plaque. In conclusion, pequi oil associated with an atherogenic diet worsens the lipid profile and accelerates the formation of advanced atherosclerotic lesions despite its antioxidant action.

Tumor growth reduction is regulated at the gene level in Walker 256 tumor-bearing rats supplemented with fish oil rich in EPA and DHA

We investigated the effect of fish oil (FO) supplementation on tumor growth, cyclooxygenase 2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARγ), and RelA gene and protein expression in Walker 256 tumor-bearing rats. Male Wistar rats (70 days old) were fed with regular chow (group W) or chow supplemented with 1 g/kg body weight FO daily (group WFO) until they reached 100 days of age. Both groups were then inoculated with a suspension of Walker 256 ascitic tumor cells (3×107 cells/mL). After 14 days the rats were killed, total RNA was isolated from the tumor tissue, and relative mRNA expression was measured using the 2-ΔΔCT method. FO significantly decreased tumor growth (W=13.18±1.58 vsWFO=5.40±0.88 g, P<0.05). FO supplementation also resulted in a significant decrease in COX-2 (W=100.1±1.62 vsWFO=59.39±5.53, P<0.001) and PPARγ (W=100.4±1.04vs WFO=88.22±1.46, P<0.05) protein expression. Relative mRNA expression was W=1.06±0.022 vsWFO=0.31±0.04 (P<0.001) for COX-2, W=1.08±0.02vs WFO=0.52±0.08 (P<0.001) for PPARγ, and W=1.04±0.02 vs WFO=0.82±0.04 (P<0.05) for RelA. FO reduced tumor growth by attenuating inflammatory gene expression associated with carcinogenesis.

Sedative and anesthetic activities of the essential oils of Hyptis mutabilis (Rich.) Briq. and their isolated components in silver catfish (Rhamdia quelen)

This study evaluated the sedative and anesthetic effects of the essential oils (EO) of Hyptis mutabilis (Rich.) Briq. and their isolated components on silver catfish (Rhamdia quelen). Quantitative chemical differences between the EOs obtained from leaves and inflorescences were verified, and a new chemotype rich in globulol was described. Although there were no significant differences in the time of induction for sedation and anesthesia between the EOs, only the leaf EO at 344 mg/L anesthetized all fish without side effects. Fractionation of the leaf EO was carried out by column chromatography. The isolated compounds [(+)-1-terpinen-4-ol and (-)-globulol] showed different activity from that detected for the leaf EO in proportional concentrations and similar sedation to a eugenol control at 10 mg/L. However, fish exposed to 1-terpinen-4-ol (3 and 10 mg/L) did not remain sedated for 30 min. Anesthesia was obtained with 83-190 mg/L globulol, but animals showed loss of mucus during induction and mortality at these concentrations. Synergism of the depressor effects was detected with the association of globulol and benzodiazepine (BDZ), compared with either drug alone. Fish exposed to BDZ or globulol+BDZ association showed faster recovery from anesthesia in water containing flumazenil, but the same did not occur with globulol. In conclusion, the use of globulol in aquaculture procedures should be considered only at sedative concentrations of 10 and 20 mg/L, and its mechanism of action seems not to involve the GABAA-BDZ system.

Evaluation of the in vitro glycemic index of a fiber-rich extruded breakfast cereal produced with organic passion fruit fiber and corn flour

The aim of this study was to determine the influence of process parameters and Passion Fruit Fiber (PFF) addition on the Glycemic Index (GI) of an extruded breakfast cereal. A 2³ Central Composite Rotational Design (CCRD) was used, with the following independent variables: raw material moisture content (18-28%), 2nd and 3rd barrel zone temperatures (120-160 ºC), and PFF (0-30%). Raw materials (organic corn flour and organic PFF) were characterized as to their proximate composition, particle size, and in vitro GI. The extrudates were characterized as to their in vitro GI. The Response Surface Methodology (RSM) and Principal Component Analysis (PCA) were used to analyze the results. Corn flour and PFF presented 8.55 and 7.63% protein, 2.61 and 0.60% fat, 0.52 and 6.17% ash, 78.77 and 78.86% carbohydrates (3 and 64% total dietary fiber), respectively. The corn flour particle size distribution was homogeneous, while PFF presented a heterogeneous particle size distribution. Corn flour and PFF presented values of GI of 48 and 45, respectively. When using RSM, no effect of the variables was observed in the GI of the extrudates (average value of 48.41), but PCA showed that the GI tended to be lower when processing at lower temperatures (<128 ºC) and at higher temperatures (>158 ºC). When compared to white bread, the extrudates showed a reduction of the GI of up to 50%, and could be considered an interesting alternative in weight and glycemia control diets.

Antioxidant capacity and chemical composition in seeds rich in omega-3: chia, flax, and perilla

The chemical composition and antioxidant capacity of five seeds, chia, golden flax, brown flax, white perilla, and brown perilla, were determined. The chemical properties analyzed included moisture, ash, crude protein, carbohydrates, total lipids, fatty acids, and antioxidant capacity (ABTS•+, DPPH•, and FRAP). The results showed the highest amounts of protein and total lipids in brown and white perilla. Perilla and chia showed higher amounts of alpha-linolenic fatty acid than those of flaxseed varieties, ranging between 531.44 mg g-1 of lipids in brown perilla, 539.07 mg g-1 of lipids in white perilla, and 544.85 mg g-1 of lipis in chia seed. The antioxidant capacity of the seeds, evaluated with ABTS•+, DPPH• , and FRAP methods, showed that brown perilla had greater antioxidant capacity when compared with white perilla, flax, and chia seeds.

Development and evaluation of iron-rich meatloaves containing pork liver for schoolchildren

AbstractIron deficiency is a highly prevalent nutritional problem worldwide and it impacts on the cognitive development of children. Therefore, the aim of this research was to develop meatloaf with high iron content by using in their formulations pork liver. Meatloaves were prepared with additions of 9.98% and 13.31% (formulations A and B) of pork liver in order to meet 15% and 20% of the daily requirement of iron (10 mg/day) for children. Samples were evaluated regarding their physicochemical, microbiological and sensory characteristics. The results were subjected to Analysis of Variance (ANOVA) followed by Tukey test. Results of physicochemical analyses showed an increase in protein and mineral contents and a decrease in fat content. The iron and zinc contents were respectively 100.0% and 70.83% (formulation A) and 152.73% and 97.92% (formulation B) higher than that of the standard formulation. Regarding fat content, the reduction of 31.5% in formulation B makes it a light product. As for the microbiological aspect, all meatloaves were adequate for consumption. Regarding sensory analysis, all the attributes considered were not statistically different, but for purchase intention test formulation B was better accepted. Therefore, formulations A and B are good sources of iron and zinc.

Vigor e viabilidade de sementes de Senna multijuga (Rich.) Irwin et Barn. e Senna macranthera (Collad.) Irwin et Barn.; num banco de sementes em solo de viveiro

A viabilidade de sementes de espécies florestais tropicais, em banco de sementes do solo, ainda é pouco estudada. No entanto, pode fornecer informações sobre o potencial de restabelecimento da floresta após distúrbios naturais ou em áreas que sofreram intervenções antrópicas. Os objetivos deste trabalho foram avaliar o vigor e a viabilidade potencial de sementes de S. multijuga e S. macranthera, em semeadura direta, em condições de viveiro e testar a eficiência do teste de tetrazólio para avaliar a viabilidade delas em laboratório. Foram realizados testes de germinação, tetrazólio e emergência de plântulas para avaliar a viabilidade inicial das sementes de ambas as espécies. O teste de tetrazólio (0,075% e 30ºC), foi utilizado, ainda, para avaliar a viabilidade potencial das sementes presentes no solo, aos 6, 12 e 18 meses. Sementes de S. multijuga apresentaram viabilidade potencial de 93,1; 65,3; 52,5 e 17,7% aos 0, 6, 12 e 18 meses, respectivamente, enquanto as sementes de S. macranthera apresentaram viabilidade potencial de 79,3; 73,9; 32,5 e 14,7% aos 0, 6, 12 e 18 meses, respectivamente. As espécies estudadas apresentaram comportamento típico daquelas que formam bancos de sementes persistentes.

Testes para monitorar a qualidade fisiológica de sementes de Brachiaria brizantha (A. Rich.) Stapf. durante o armazenamento

O trabalho teve como objetivo avaliar a eficiência dos testes de envelhecimento acelerado e de deterioração controlada para monitorar a qualidade fisiológica de sementes de B. brizantha durante o armazenamento. Três lotes de sementes não escarificadas e escarificadas com H2SO4 concentrado foram acondicionados em embalagem permeável e armazenadas em condições de ambiente no Laboratório de Sementes do DFT/UFV no período de dezembro de 1999 a agosto de 2000. Foram, então, submetidos aos testes de germinação, envelhecimento acelerado a 43ºC/48h e 60h a 100% e 76 % UR, deterioração controlada a 45ºC/24h em sementes com 20 e 24% de umidade e índice de velocidade de emergência de plântulas. As avaliações foram feitas aos 0, 60, 120, 180 e 240 dias de armazenamento. O envelhecimento acelerado conduzido a 43ºC e 100% UR por 48h foi o procedimento mais eficiente para monitorar o comportamento das sementes de B. brizantha durante o armazenamento, fornecendo informações correlacionadas ao índice de velocidade de emergência das plântulas.

Duração do teste de germinação de Brachiaria brizantha cv. marandu (Hochst. ex A. Rich.) Stapf

O presente trabalho objetivou determinar o tempo mínimo necessário à realização do teste de germinação para sementes de B. brizantha cv. Marandu, o método de superação de dormência e a condição de temperatura que proporcionem a maior germinação no menor tempo. Numa primeira etapa, realizou-se o teste de germinação em trinta lotes de sementes, sob duas condições de temperaturas (15-35ºC e 20-35ºC), avaliadas em conjunto com três métodos para a superação de dormência (H2SO4, KNO3 e Controle), constituindo seis tratamentos. Realizaram-se contagens diárias da germinação para a determinação da data mais apropriada para o término do teste. Na segunda etapa, realizaram-se testes de germinação em oito lotes de diferentes níveis de vigor, utilizando-se os mesmos seis tratamentos e com encerramento do teste nas datas definidas na primeira etapa. Conclui-se que, para o teste de germinação de B. brizantha, a escarificação com H2SO4 e a temperatura de 20-35ºC são tratamentos que resultam na maior germinação em um menor tempo, possibilitando o encerramento do teste aos 11 dias após a semeadura.

Avaliação da viabilidade de sementes de Brachiaria brizantha (Hochst. ex A. Rich) Stapf pelo teste de tetrazólio

As sementes de Brachiaria brizantha apresentam dormência, principalmente quando recém colhidas, o que torna o teste de germinação ineficiente para avaliar a viabilidade, sendo necessária a realização do teste de tetrazólio. Visando comparar as metodologias mais utilizadas na condução do teste de tetrazólio nestas sementes, determinou-se a viabilidade de quatro lotes da cultivar Marandu, com diferentes qualidades fisiológicas e intensidades de dormência, em cinco épocas trimestrais. O teste de tetrazólio foi conduzido com as seguintes concentrações de 2,3,5 trifenil cloreto tetrazólio: 1,0% (conforme metodologia prescrita pela International Seed Testing Association - ISTA); 0,2% e 0,1% (sem descarte de uma metade da semente). Como teste referencial foi realizada a germinação sem e com tratamento para superar a dormência, utilizando a escarificação em ácido sulfúrico. Os resultados dos testes de tetrazólio obtidos com as menores concentrações não diferiram da metodologia recomendada pela ISTA, mas facilitaram a interpretação, devido a melhor visualização da estrutura embrionária. O tratamento para superação da dormência não foi eficiente para todas as sementes e prejudicou a germinação das não dormentes. Os testes de tetrazólio e de germinação podem ser considerados como complementares e, em conjunto, permitem avaliar a qualidade fisiológica das sementes de Brachiaria brizantha.

Morfoanatomia e histoquímica da semente de sororoca (Phenakospermum guyannense (Rich.) Endl. - Strelitziaceae)

Phenakospermum guyannense é popularmente conhecida na Amazônia como sororoca, geralmente encontrada próxima a cursos d´água, em ambientes ombrófilos. Objetivou-se com este estudo descrever a morfoanatomia e histoquímica da semente madura de P. guyannense, como contribuição a estudos taxonômicos, fisiológicos e ecológicos. Sementes maduras foram coletadas nas margens da Cachoeira do Urubuí, no Município de Presidente Figueiredo, Amazonas. O estudo anatômico foi realizado conforme técnicas usuais para análise em microscopia óptica e eletrônica de varredura. Foram aplicados testes histoquímicos para a detecção de compostos fenólicos, amido, proteína e lipídios. A semente madura de P. guyannense é estenospérmica, com envoltório de cor negra, formado por vários estratos de diferentes tipos celulares, sendo a maioria impregnada de compostos fenólicos. O hilo é punctiforme, circundado por células que constituem o arilo. O endosperma é sólido, constituído por células tetraédricas de conteúdo amiláceo e proteico. O embrião é basal capitado, apresentando células de conteúdo lipídico e proteico, composto por eixo hipocótilo-radícula levemente dilatado de forma cilíndrica e localiza-se na região proximal. O haustório apresenta formato aplanado e situa-se na região distal.