1. Investigación

In the present work, for the first time in the literature, the relationship between the degree of air pollution, the physiological state of the plants and the allergenic capacity of the pollen they produce has been studied. The physiological state of Lolium perenne plants growing in two cities with a high degree of traffic, but with different levels of air pollution, Madrid and Ciudad Real, have been explored. The photosynthetic efficiency of the plants through the emission of fluorescence of PSII, the degree of oxidative stress (enzymatic activities related to the ascorbate-glutathione cycle), the redox state (reduced and oxidized forms of ascorbate and glutathione) and the concentration of malondialdehyde have been evaluated. During the development period of the plants, Madrid had higher levels of NO2 and SO2 than Ciudad Real. The greater degree of air pollution suffered by Madrid plants was reflected on a lower photosynthetic efficiency and a greater degree of oxidative stress. In addition, NADPH oxidase activity and H2O2 levels in pollen from Madrid were significantly higher, suggesting a likely higher allergenic capacity of this pollen associated to a higher air pollution.

Exposure to ultraviolet-B (UV-B) radiation can lead to oxidative damage in plants, increasing reactive oxygen species (ROS) production. To overcome ROS burst, plants have antioxidant mechanisms related to ROS scavenging which can be improved by elicitation with biological agents or derived molecules (elicitors), as they can trigger a physiological alert state called “priming”. This work describes the effects of lipo-chitooligosaccharides (LCOs) treatment applied to tomato plants under UV-B stress. The LCOs used in the study are produced by three species of the genus Ensifer (formerly Sinorhizobium) (SinCEU-1, SinCEU-2, and SinCEU-3) were assayed on tomato plants under UV-B stress. LCOs were able to significantly increase most of the enzymatic activities related to ROS scavenging while non-enzymatic antioxidants were not modified. This response was associated with a lower oxidative stress, according to malondialdehyde (MDA) levels and the higher antioxidant capacity of the plants. Furthermore, the photosynthetic efficiency of LCOs-treated plants indicated a better physiological state than the control plants. Therefore, although more studies and deepening of certain aspects are necessary, LCOs have shown great potential to protect plants from high UV-B radiation conditions.

Plants belonging to the genus Taraxacum are considered a nutritious food, being consumed raw or cooked. Additionally, these plants have long been used in folk medicine due to their choleretic, diuretic, antitumor, antioxidant, antiinflammatory, and hepatoprotective properties. This genus, with its complex taxonomy, includes several species that are difficult to distinguish. Its traditional use must be related not only to T. officinale F.H. Wigg., the most studied species, but also to others. The aim of this work is to compare five different common South European species of Taraxacum (T. obovatum (Willd.) DC., T. marginellum H. Lindb., T. hispanicum H. Lindb., T. lambinonii Soest and T. lacistrum Sahlin), in order to find differences between antioxidant and cytotoxic activities among them. Dissimilarities between species in LC/MS patterns, in in vitro and intracellular antioxidant activity and also in the cytotoxicity assay were found. T. marginellum was the most efficient extract reducing intracellular ROS levels although in in vitro assays, T. obovatum was the best free radical scavenger. A relevant cytotoxic effect was found in T. lacistrum extract over HeLa and HepG2 cell lines.

This study aims to analyse sex-specific associations of physical activity and sedentary behaviour with oxidative stress and inflammatory markers in a young-adult population. Sixty participants (21 women, 22.63 4.62 years old) wore a hip accelerometer for 7 consecutive days to estimate their physical activity and sedentarism. Oxidative stress (catalase, superoxide dismutase, glutathione peroxidase, glutathione, malondialdehyde, and advanced oxidation protein products) and inflammatory (tumour necrosis factor-alpha and interleukin-6) markers were measured. Student t-tests and single linear regressions were applied. The women presented higher catalase activity and glutathione concentrations, and lower levels of advanced protein-oxidation products, tumour necrosis factor-alpha, and interleukin-6 than the men (p < 0.05). In the men, longer sedentary time was associated with lower catalase activity (b = 􀀀0.315, p = 0.04), and longer sedentary breaks and higher physical-activity expenditures were associated with malondialdehyde (b = 􀀀0.308, p = 0.04). Vigorous physical activity was related to inflammatory markers in the women (tumour necrosis factor-alpha, b = 0.437, p = 0.02) and men (interleukin􀀀6, b = 0.528, p < 0.01). In conclusion, the women presented a better redox and inflammatory status than the men; however, oxidative-stress markers were associated with physical activity and sedentary behaviours only in the men. In light of this, women could have better protection against the deleterious effect of sedentarism but a worse adaptation to daily physical activity.