Nanopartículas de quitosán mejoran el rendimiento, actividad enzimática y compuestos bioactivos en frutos de tomate

Las nanopartículas de quitosán (NPsCS) son utilizadas como bioestimulantes naturales en la agricultura sustentable, ya que incrementan la productividad de los cultivos e inducen la síntesis de antioxidantes enzimáticos y no enzimáticos, protegiendo a la planta del estrés. El presente estudio se desarrolló con el objetivo de determinar el efecto de la aplicación foliar de las NPsCS sobre el rendimiento, actividad enzimática y contenido de compuestos bioactivos en frutos de tomate. El ensayo se estableció en un diseño completamente al azar con seis dosis crecientes de NPsCS: 0, 0.05, 0.1, 0.2, 0.4 y 0.8 mg mL-1. La aspersión foliar de 0.2 mg mL-1 aumentó el rendimiento, tamaño y firmeza de los frutos; en cambio dosis alta incrementan los compuestos bioactivos y la actividad enzimática. El uso de NPsCS aplicadas de forma foliar presentan un gran potencial para utilizarse como bioestimulantes para mejorar el rendimiento y obtener alimentos funcionales

Agronomic biofortification with selenium improves the yield and nutraceutical quality in tomato under soilless conditions

Selenium (Se) is an essential element for humans. Its consumption comes from food of animal or vegetal origin; whose content varies widely depending on its availability in soil or anthropogenic sources. Biofortification improves food nutritional quality, and its consumption has a positive influence in human health. Thus, the objective of this research was to assess agricultural biofortification with Se in tomato fruit and its effects on yield, nutraceutical quality, and antioxidant capacity.  Five Se doses (0, 2, 4, 6, and 8 mg L-1) in the form of sodium selenite (Na2SeO3) were added in a nutritional solution in a hydroponic system.  The results obtained indicated that agricultural biofortification with Se applied in the nutritional solution improved yield, nutraceutical quality, and Se concentration in tomato fruit. The optimum Se dose that maximized yield and nutraceutical quality, as well as the recommended consumption concentration in tomato fruit in this study was 2 mg L-1 (Na2SeO4) because higher doses decreased yield and bioactive compound biosynthesis. Incorporating Se in the nutritional solution is an alternative to increase phytochemical compound biosynthesis in tomato fruit and yield with the possibility of improving public health with its consumption

Copper oxide nanoparticles biosynthetized improve germination and bioactive compounds in wheat sprouts

Metal nanoparticles have many positive effects in improving crop production and productivity and allow for increased germination and rapid crop establishment under field conditions. The metallic nanoparticles applied in this study were copper oxide nanoparticles (CuONPs) biosynthesized using orange peel (Citrus X sinensis) as a reducing agent to avoid or reduce toxicity in wheat seeds and sprouts. This study determined the effect of CuONPs on germination, radicle and plumule length, as well as the production of phytochemical compounds in wheat sprouts. The seeds were treated with suspensions of CuONPs at the following concentrations: 0, 0.5, 1, 2, 4 and 6 mg mL-1. The results indicate that the use of low doses of CuONPs (0.5 mg mL-1), improved germination, vigor, plumule and radicle length, in addition to increasing the biosynthesis of phytochemical compounds in wheat shoots. A high concentration of CuONPs (6 mg mL-1) causes inhibitory effects due to Cu accumulation and phytotoxicity in plant tissue. The use of CuONPs for green synthesis is a viable alternative to obtain beneficial effects in germination and seedling development, as well as greater secondary metabolite production

Plantas medicinales utilizadas para enfermedades del sistema digestivo en Tetela del Volcán, Estado de Morelos, México

Los mexicanos han utilizado las plantas medicinales para las enfermedades del sistema digestivo desde la época prehispánica, actualmente son particularmente empleadas en las comunidades pobres. Se describe el uso de las plantas medicinales para curar dicho tipo de padecimientos en la comunidad de Tetela del Volcán. Se realizaron colectas guiadas de material botánico y 92 entrevistas semi- estructuradas a 59 informantes. Se registraron 78 especies pertenecientes a 70 géneros y 36 familias. Las familias Asteracea y Lamiaceae dominan culturalmente. La mayoría de las especies son cultivadas y se usan preferentemente las ramas. De 24 enfermedades, el dolor de estómago y la diarrea fueron las más importantes. Las especies Matricaria chamomilla L., Mentha x piperita L., Artemisia absinthium L. yPsidium guajava L. tuvieron los mayores Índices de Fidelidad de Friedman modificados. Este patrimonio biocultural contribuye en la salud y, por lo tanto, al bienestar de los habitantes de Tetela del Volcán

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Antibacterial activity of chitosan and the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan

The antimicrobial activity of chitosan and water soluble interpolyelectrolyte complexes of poly(acrylic acid)-chitosan was studied. Chitosans of two different molecular weights were tested at different concentration for 0.5 to 5 g·L-1 as antimicrobial agents against P. aeruginosa and P. oleovorans. In both cases, the best microbial inhibition was obtained with the concentration of 5 g·L-1. However, the interpolyelectrolyte complexes of poly(acrylic acid)-chitosan with composition &#966; =2 produced higher antibacterial activity than the two chitosans at the concentration of 0.5 g·L-1. The NPEC2 complex was more effective than chitosans. This could be attributed to the number of moles of the amino groups of chitosan and the carboxylic acid groups of the interpolyelectrolyte complexes poly(acrylic acid).A atividade antimicrobiana de quitosana e complexos interpolieletrolíticos hidrossoluvéis de poli(ácido acrílico)-quitosana foi estudada. Quitosanas de dois diferentes pesos moleculares foram testados em diferentes concentrações, 0,5 a 5 g • L-1, como agentes antimicrobianos nas P. aeruginosa e P. oleovorans. Em ambos os casos, obteu-se a melhor inibição microbiana com a concentração de 5 g • L-1, no entanto os complexos interpolieletrolíticos de poli (ácido acrílico)-quitosana com composição &#966; = 2 apresentaram maior atividade antibacteriana do que os dois quitosans na concentração de 0,5 g • L-1. O complexo NPEC2 foi mais eficaz do que as quitosanas, sendo que o resultado pode ser atribuído ao número de moles dos grupos aminos da quitosana e aos grupos carboxílicos dos complexos de poli(ácido acrílico)

Effects of Chitosan–PVA and Cu Nanoparticles on the Growth and Antioxidant Capacity of Tomato under Saline Stress

Chitosan is a natural polymer, which has been used in agriculture to stimulate crop growth. Furthermore, it has been used for the encapsulation of nanoparticles in order to obtain controlled release. In this work, the effect of chitosan–PVA and Cu nanoparticles (Cu NPs) absorbed on chitosan–PVA on growth, antioxidant capacity, mineral content, and saline stress in tomato plants was evaluated. The results show that treatments with chitosan–PVA increased tomato growth. Furthermore, chitosan–PVA increased the content of chlorophylls a and b, total chlorophylls, carotenoids, and superoxide dismutase. When chitosan–PVA was mixed with Cu NPs, the mechanism of enzymatic defense of tomato plants was activated. The chitosan–PVA and chitosan–PVA + Cu NPs increased the content of vitamin C and lycopene, respectively. The application of chitosan–PVA and Cu NPs might induce mechanisms of tolerance to salinity

Use of Chitosan-PVA Hydrogels with Copper Nanoparticles to Improve the Growth of Grafted Watermelon

Modern agriculture requires alternative practices that improve crop growth without negatively affecting the environment, as resources such as water and arable land grow scarcer while the human population continues to increase. Grafting is a cultivation technique that allows the plant to be more efficient in its utilization of water and nutrients, while nanoscale material engineering provides the opportunity to use much smaller quantities of consumables compared to conventional systems but with similar or superior effects. On those grounds, we evaluated the effects of chitosan-polyvinyl alcohol hydrogel with absorbed copper nanoparticles (Cs-PVA-nCu) on leaf morphology and plant growth when applied to grafted watermelon cultivar ‘Jubilee’ plants. Stomatal density (SD), stomatal index (SI), stoma length (SL), and width (SW) were evaluated. The primary stem and root length, the stem diameter, specific leaf area, and fresh and dry weights were also recorded. Our results demonstrate that grafting induces modifications to leaf micromorphology that favorably affect plant growth, with grafted plants showing better vegetative growth in spite of their lower SD and SI values. Application of Cs-PVA-nCu was found to increase stoma width, primary stem length, and root length by 7%, 8% and 14%, respectively. These techniques modestly improve plant development and growth

Chitosan-PVA and Copper Nanoparticles Improve Growth and Overexpress the SOD and JA Genes in Tomato Plants under Salt Stress

Saline stress severely affects the growth and productivity of plants. The activation of hormonal signaling cascades and reactive oxygen species (ROS) in response to salt stress are important for cellular detoxification. Jasmonic acid (JA) and the enzyme SOD (superoxide dismutase), are well recognized markers of salt stress in plants. In this study, the application of chitosan-polyvinyl alcohol hydrogels (Cs-PVA) and copper nanoparticles (Cu NPs) on the growth and expression of defense genes in tomato plants under salt stress was evaluated. Our results demonstrate that Cs-PVA and Cs-PVA + Cu NPs enhance plant growth and also promote the expression of JA and SOD genes in tomato (Solanum lycopersicum L.), under salt stress. We propose that Cs-PVA and Cs-PVA + Cu NPs mitigate saline stress through the regulation of oxidative and ionic stress

Cu Nanoparticles in Hydrogels of Chitosan-PVA Affects the Characteristics of Post-Harvest and Bioactive Compounds of Jalapeño Pepper

Peppers are consumed all over the world due to the flavor, aroma, and color that they add to food. Additionally, they play a role in human health, as they contain a high concentration of bioactive compounds and antioxidants. The treatments used were an absolute control, Cs-PVA, and four treatments with 0.02, 0.2, 2, and 10 mg (nCu) g−1 (Cs-PVA). The application of Cu nanoparticles in chitosan-PVA hydrogels increases the content of capsaicin by up to 51% compared to the control. This application also increases the content of antioxidants ABTS [2,2′-azino-bis (3-ethylbenzothiazolin-6-sulfonic acid)] and DPPH (2,2-diphenyl-1-picrylhydrazyl), total phenols and flavonoids (4%, 6.6%, 5.9%, and 12.7%, respectively) in jalapeño pepper fruits stored for 15 days at room temperature; under refrigeration, it increases DPPH antioxidants, total phenols, and flavonoids (23.9%, 1.54%, and 17.2%, respectively). The application of Cu nanoparticles in chitosan-PVA hydrogels, even when applied to the substrate, not only has an effect on the development of the jalapeño pepper crop, but also modifies the post-harvest characteristics of the jalapeño pepper fruits