Phytotoxic activity of Cachrys pungens Jan,a mediterranean species: separation,identification and quantification of potential allelochemicals

In continuous research for bioactive compounds obtained from plants to use for weed control in sustainable agriculture, the aerial parts of Cachrys pungens Jan (Umbelliferae) were extracted with methanol and then fractionated using hexane, chloroform (CHCl₃) and ethyl acetate (AcOEt). The potential phytotoxicity of total methanolic extract and each fraction was assayed in vitro on seed germination and root elongation of lettuce (Lactuca sativa L.) and the most active fractions were assayed on three of the most common weeds (Lolium perenne, Amaranthus retroflexus, Echinochloa crus-galli). Non linear regression that allowed to obtain the ED₅₀ index for both physiological processes was applied. The fraction bioassays indicated the following hierarchy of phytotoxicity for both processes: CHCl₃ ≥ AcOEt > hexane. Moreover, in the present work was chemically characterized for the first time (through HPTLC) the polar fraction of this species pointing out the high presence of flavonoids and phenolic acids. In particular six of them have been chemically characterized and quantified (naringin, quercetin, catechin, caffeic acid, ferulic acid and gallic acid). These results make C. pungens Jan a potential source of natural compounds employable for an eco-friendly agriculture.     

Glutathionylation of the Aquaporin-2 Water Channel: A NOVEL POST-TRANSLATIONAL MODIFICATION MODULATED BY THE OXIDATIVE STRESS*

Aquaporin-2 (AQP2) is the vasopressin-regulated water channel that controls renal water reabsorption and urine concentration. AQP2 undergoes different regulated post-translational modifications, including phosphorylation and ubiquitylation, which are fundamental for controlling AQP2 cellular localization, stability, and function. The relationship between AQP2 and S-glutathionylation is of potential interest because reactive oxygen species (ROS), produced under renal failure or nephrotoxic drugs, may influence renal function as well as the expression and the activity of different transporters and channels, including aquaporins. Here, we show for the first time that AQP2 is subjected to S-glutathionylation in kidney and in HEK-293 cells stably expressing AQP2. S-Glutathionylation is a redox-dependent post-translational modification controlling several signal transduction pathways and displaying an acute effect on free cytosolic calcium concentration. Interestingly, we found that in fresh kidney slices, the increased AQP2 S-glutathionylation correlated with tert-butyl hydroperoxide-induced ROS generation. Moreover, we also found that cells expressing wild-type human calcium-sensing receptor (hCaSR-wt) and its gain of function (hCaSR-R990G; hCaSR-N124K) had a significant decrease in AQP2 S-glutathionylation secondary to reduced ROS levels and reduced basal intracellular calcium concentration compared with mock cells. Together, these new findings provide fundamental insight into cell biological aspects of AQP2 function and may be relevant to better understand and explain pathological states characterized by an oxidative stress and AQP2-dependent water reabsorption disturbs.     

Is polyandry a common event among wild populations of the pest Ceratitis capitata?

In many insect species, females can mate more than once and store sperm from more than one male. An assessment and understanding of polyandry in the field can be important for pest species with a high colonization potential, such as the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), which is also highly polyphagous and among the most destructive agricultural insects. The use of polymorphic microsatellite markers, combined with different statistical approaches, provides evidence that polyandry occurs in two C. capitata natural populations, one population from the Greek island of Chios and one population from Rehovot, in Israel. The observed different level of polyandry is discussed in relation to the genetic diversity, seasonality, and demography of the two populations. When polyandry is present, paternity analysis also indicates that one male, presumably the last, tends to sire most of the progeny. Polyandry and paternity skew may have important implications for the evolution of the species, in terms of maintenance of the genetic variability. Moreover, these aspects of the mating behavior, i.e., remating frequency and paternity skew, may locally affect the sterile insect technique, the most commonly applied control strategy against C. capitata.     

In vitro cell cultures obtained from different explants of Corylus avellana produce Taxol and taxanes

Background  

Taxol is an effective antineoplastic agent, originally extracted from the bark of Taxus brevifolia with a low yield. Many attempts have been made to produce Taxol by chemical synthesis, semi-synthesis and plant tissue cultures. However, to date, the availability of this compound is not sufficient to satisfy the commercial requirements. The aim of the present work was to produce suspension cell cultures from plants not belonging to Taxus genus and to verify whether they produced Taxol and taxanes. For this purpose different explants of hazel (Corylus avellana species) were used to optimize the protocol for inducing in vitro callus, an undifferentiated tissue from which suspension cell cultures were established.     

Daily and Seasonal Extranidal Behaviour Variations in the Invasive Yellow-Legged Hornet, <Emphasis Type="Italic">Vespa velutina</Emphasis> Lepeletier (Hymenoptera: Vespidae)

In eusocial insect species, the nest represents the fundamental element of the colony. Extranidal activities (foraging, nest maintenance, defence) are fundamental for the development and the survival of the colony. Therefore, they may represent interesting targets to disrupt to limit their expansion in case of pest species such as Vespa velutina, an alien predator of domestic honeybees in Europe. An accurate knowledge of the pattern of activity of this pest’s colonies is therefore required. Due to the highly defensive nature of this hornet, a video monitoring was realized on two colonies during their growth from August to November. Three major behaviours were monitored: nest maintenance, patrolling on the nest and foraging flights. Although of different size and monitored during different years, the two colonies exhibited similar patterns of daily and seasonal variation. This work is a first step in the study of this pest especially in view of control program.     

Schooltime subjective sleepiness and performance in Italian primary school children

Despite its clinical importance, the issue of the diurnal time course of sleepiness and performance in children remains largely unexplored. The objective of this study is to draw a profile of daytime subjective sleepiness and performance, at simple and complex tasks, in a cohort of Italian primary school children.To this aim, a sample of 316 children (age range: 5–11 years; mean 8.2 ± 1.5) was recruited and sub-divided into three groups, according to age: Group 1 (5–7 years; N = 127), Group 2 (8–9 years; N = 108), Group 3 (10–11 years; N = 81). Subjective sleepiness and simple performance were evaluated, respectively, through the Pictorial Sleepiness Scale and the Simple Reaction Time Task. Executive functions were addressed by means of the “Go/No-Go Task.” Measurements were made in the children’s class three times a day, one day a week over a 3-week period in order to reliably reflect the habitual time course of sleepiness and performance, within the following time intervals: a) 8:30 am–10:30 am; b) 11 am–1 pm; c) 2 pm–4 pm.For the global sample, a significant increase of subjective sleepiness was found at the end of school day (2–4 pm), although at relatively low levels. No significant differences were observed in reaction times across the day, whereas a significant worsening was detected in performance at complex task already since mid-morning. Significant correlations were found between subjective sleepiness and complex performance at all points.Slight age-related differences were found in the time courses of subjective sleepiness: in fact, a significant overday reduction of vigilance levels, from mid-morning onwards, was observed in children aged 5–9 years, but not in the older children (10–11 years). However, the daily time course of both simple and complex performances did not differ among children of the three age groups. Our results show changes in vigilance and cognitive functions across a typical school day in childhood, as well as age-related differences in sleepiness profile, that we suggest to thoroughly consider when conceiving chronopsychological interventions in the school context.