Guarana (Paullinia cupana) is habitually ingested by people in the Amazon region and is a key ingredient in various energy drinks consumed worldwide. Extension in longevity and low prevalence of chronic age-related diseases have been associated to habitual intake of guarana. Anti-aging potential of guarana was also demonstrated in Caenorhabditis elegans; however, the mechanisms involved in its effects are not clear. Herein, we investigated the putative pathways that regulate the effects of guarana ethanolic extract (GEE) on lifespan using C. elegans. The major known longevity pathways were analyzed through mutant worms and RT-qPCR assay (DAF-2, DAF-16, SKN-1, SIR-2.1, HSF-1). The possible involvement of purinergic signaling was also investigated. This study demonstrated that GEE acts through antioxidant activity, DAF-16, HSF-1, and SKN-1 pathways, and human adenosine receptor ortholog (ADOR-1) to extend lifespan. GEE also downregulated skn-1, daf-16, sir-2.1 and hsp-16.2 in 9-day-old C. elegans, which might reflect less need to activate these protective genes due to direct antioxidant effects. Our results contribute to the comprehension of guarana effects in vivo, which might be helpful to prevent or treat aging-associated disorders, and also suggest purinergic signaling as a plausible therapeutic target for longevity studies.

This study evaluated the productive response and chemical composition of sorghum hybrid BR 601 to nitrogen fertilization. The experimental design was randomized blocks with five replications. The treatments were: 0, 50, 100, 150 and 200 kg N/ha (ammonium sulfate). There was a quadratic increase of yield with N fertilization, the higher value was obtained with 143.19 kg of N/ha for fresh matter (37996 kg/ha) and with 155.67 kg of N/ha for dry matter (16 275 kg/ha). The production of leaf and dead material at the plant did not differ between treatments. The percentage of stem in the plant decreased quadratically up to a dose of 100 kg/ha and the panicle component increased quadratically to 30,96%. So, this component was the main responsible for increase in DM yield. The average plant dry matter varied from 34.84% to 38.98% in the treatment with 200 kg N/ha. The levels of MM decreased (6.41 to 5.49%) and crude protein increased linearly (from 4.99% to 6.23%) with increasing doses of N. The levels of neutral detergent fiber, acid detergent fiber and hemicellulose did not differ in relation to nitrogen fertilization. The nitrogen increases the production of dry matter and panicle without changing the fiber constituents of the plant.

Objetivou-se avaliar a resposta produtiva e a composição bromatológica do sorgo híbrido BR 601 ao incremento da adubação nitrogenada. O delineamento experimental utilizado foi em blocos casualizados com cinco repetições. Os trata-mentos foram: 0, 50, 100, 150 e 200 kg/ha de N (sulfato de amônio). A produção variou de forma quadrática ao incremento da adubação nitrogenada, o ponto de máxima para a materia verde foi obtido com 143,19 kg de N/ha (37 996 kg/ha) e para matéria seca com 155,67 kg de N/ha (16 275 kg/ha). A produção de lâmina foliar e material morto na planta não diferiu entre os tratamentos. O percentual de colmo na planta diminuiu de forma quadrática até a dose de 100 kg/ha, o componente panícula aumentou de forma quadrática em 30,96%, o que explica que este componente foi o principal responsável pelo aumento na PMS. O percentual médio de matéria seca da planta variou de 34,84% no tratamento controle a 38,98% no tratamento com 200 kg de N/ha. Os teores de MM diminuíram (6,41 a 5,49%). O teor de PB incrementara linearmente com o aumento nas doses de adubo aplicadas, com variação no teor protéico de 4,99% a 6,23%, respectivamente nos tratamentos 0 e 200 kg de N/ha. Os teores de fibra em detergente neutro, fibra em detergente ácido e hemicelulose não diferiram em função da adubação nitrogenada. A adubação nitrogenada aumenta a produção de matéria seca e panícula sem alterar os constituintes fibrosos da planta.

Aimed to evaluate the morphogenetic and structural characteristics of the pasture of Brachiaria decumbens, subjected to several intensities and frequencies of cutting and nitrogen fertilization. Experimental design was randomized blocks in split plots, whit a 2 x 2 factorial arrangement relating to combinations of two cutting heights (40 and 50 cm) and two heights of residue (15 and 25 cm) at the plots and nitrogen fertilization (with or without nitrogen) in sub-plots, with four replications. Mophogenetic variables evaluated were: leaf elongation rate (LER), stem elongation rate (SER), leaf appearance rate (LAR), leaf senescence rate (LSR) and phyllochron; and structural features were: number of basal tillers (NBT), total number of leaves (TNL), number of leaves appeared (NLAp), number of dead leaves (NDL), number of alive leaves (NAL) and final leaf length (FLL). 100 kg N/ha allowed increase (p<0.10) on LER of 31.58% and 126.32% respectively for residues 15 and 25 cm. The NBT compared to cutting heights (40 to 50 cm) were affected (p<0.10) only with the use of nitrogen fertilizer, with average of 145.62 tillers/m² in 50 cm cut height. Residue height of 25 cm combined with cut height 40 cm increase leaf elongation rate and number of basal tillers, reducing expansion time, without changing other structural characteristics of the pasture.

Objetivou-se avaliar as características morfogênicas e estruturais do pasto de Brachiaria decumbens, submetido a intensidades, frequências de corte e adubação nitrogenada. O delineamento experimental foi em blocos casualizados em esquema de parcelas subdivididas, tendo na parcela o arranjo fatorial 2 x 2 referente a combinações entre duas alturas de corte (40 e 50 cm) e duas alturas de resíduo (15 e 25 cm) e nas sub-parcelas a adubação nitrogenada (com ou sem nitrogênio), com quatro repetições. As variáveis analisadas para as características morfogênicas foram: taxa de alongamento foliar (TAlF); taxa de alongamento de colmo (TAlC); taxa de aparecimento foliar (TApF); taxa de senescência foliar (TSF) e filocrono; e para as características estruturais foram: número de perfilhos basais (NPB); número de folhas totais (NFT); número de folhas aparecidas (NFAp); número de folhas mortas (NFM); número de folhas vivas (NFV) e comprimento final da folha (CFF). A utilização de 100 kg/ha de N permitiu aumento (p<0,10) na TAlF de 31,58% e 126,32%, respectivamente para os resíduos de 15 e 25 cm. O NPB em comparação às alturas de corte (40 e 50 cm) foi afetado (p<0,10) apenas com a utilização da adubação nitrogenada, observando-se média de 145,62 perfilhos/m² para a altura de corte 50 cm. A altura de resíduo 25 cm combinada com a altura de corte 40 cm, junto à aplicação de 100 kg/ha de N, promovem maior produção de matéria seca total em menor espaço de tempo (28 dias), permitindo maiores taxas de lotação e facilitando o manejo no sistema de lotação rotacionada.