Novel Neuroprotective Potential of Crocin in Neurodegenerative Disorders: An Illustrated Mechanistic Review

Neurochemical Research - Neurodegenerative disorders are characterized by mitochondrial dysfunction and subsequently oxidative stress, inflammation, and apoptosis that contribute to neuronal...     

Physiology of Hibernating Larvae of the Pistachio Twig Borer, <Emphasis Type="Italic">Kermania pistaciella</Emphasis> Amsel (Lepidoptera: Tineidae), Collected from Akbari Cultivar of <Emphasis Type="Italic">Pistacia vera</Emphasis> L.

The pistachio twig borer, Kermania pistaciella Amsel (Lepidoptera: Tineidae), a key pest of pistachio trees, is a monovoltine pest living inside the feeding tunnel of pistachio twigs for almost 10 months in a year and overwinters there as last instar larvae. In this study, we measured some physiological parameters of overwintering field collected larvae of the pest. There were no changes in trehalose, glucose, and myo-inositol contents, but there were differences in the levels of total simple sugar and glycogen during overwintering. Total sugar content at the beginning of overwintering (October) was at the lowest level (24.13 mg/g body weight) and reached to the highest level (55.22 mg/g fresh body weight) in November whereas glycogen content was at the highest level (44.05 mg/g fresh body weight) in October and decreased to 18.42 mg/g fresh body weight in November. Decrease in lipid content during the overwintering period was not significant. The highest and lowest levels of protein content were recorded in January and February, respectively. Supercooling points (SCP) of the overwintering larvae were stable and low (ranged between ?17.80 and ?25.10°C) throughout the cold season and no larva survived after SCP determination. The lowest cold hardiness (60 and 0.0% survival following exposure to ?10 and ?20°C/24 h, respectively) was observed for in November-collected larvae. Overwintering larvae of the pistachio twig borer rely mostly on maintaining the high supercooling capacity throughout the overwintering to avoid freezing of their body fluid.     

The Effect of Stress on Salivary Metal Ion Content in Orthodontic Patients

Psychological stress can alter the environment in favor of corrosion of orthodontic alloys by changing the properties of saliva. This study aimed to assess the effect of stress induction on salivary nickel and chromium content in fixed orthodontic patients. Thirty patients were enrolled in this experiment. Saliva sample collection was performed at four time points: T1, before insertion of orthodontic appliances; T2, 3 months after the initiation of orthodontic treatment, before induction of stress; T3, 15 min following the induction of stress by Trier Social Stress Test; and T4, 30 min following the induction of stress. Ion content was measured by atomic absorption spectrophotometry. The obtained data were analyzed by repeated measures analysis of variance (ANOVA) and post hoc Bonferroni test. The mean amount of salivary nickel increased from 11.9?±?5.1 μg/L at T1 to 14.1?±?5.3 μg/L at T4. This increase was found significant only at T4 comparing to T1. The average salivary chromium content changed from 4.1?±?2.3 μg/L at T1 to 5.1?±?3.3 μg/L at T4. None of the differences were significant for chromium. In conclusion, induction of stress in this study led to a significant increase in nickel release from orthodontic appliances into saliva. The salivary chromium content however was not significantly altered, yet gradually increased.     

Quantification of the Effect of Environmental Factors on Seed Germination and Seedling Growth of Eruca (Eruca sativa) Using Mathematical Models

Eruca (Eruca sativa; Brassicaceae) is an important industrial crop due to its ability to grow under a wide range of climatic conditions and in poor fertility lands and also for the quality of seed oil and protein. Seed germination (SG) is an important event in plant’s life history which can significantly be influenced by several environmental factors such as temperature (T), water potential (ψ), salinity, pH, and burial depth. Therefore, this study aimed (i) to investigate the effects of these environmental factors on SG behavior of Eruca using several mathematical models, (ii) to determine the cardinal Ts and tolerance threshold value for each trait (i.e., 50% reduction than its maximum value) affected by the environmental factor, and (iii) to quantify the response of Eruca seedling growth to each environmental factor. The results indicated that Eruca SG and seedling growth were significantly influenced by these factors (P < 0.05). The estimated cardinal Ts were 1 °C for the base T, 30 °C for the optimum T, and 40.8 °C for the ceiling T. The salt and drought tolerance threshold values were 257 mM NaCl and − 1.2 MPa for SG and 247 mM NaCl and − 1 MPa for the seedling growth, respectively, suggesting that the seedling growth was more sensitive than SG under both salt and drought stresses in Eruca. In addition, the maximum SG and seedling growth were observed at pH 7 and burial depth 1.9 cm. In general, the models used in this study could describe well the response of Eruca SG under different levels of environmental factors and also their parameters could easily be used in Eruca SG simulation models. This information also could help us to better manage the production of this plant under stressful conditions and/or to determine its geographic range expansion in the world.

     

Anti-inflammatory Effect of Seeds and Callus of Nigella sativa L. Extracts on Mix Glial Cells with Regard to Their Thymoquinone Content

Anti-inflammatory effect of the alcoholic extracts of N. sativa seeds and its callus on mix glial cells of rat with regard to their thymoquinone (TQ) content was investigated. Callus induction was achieved for explants of young leaf, stem, petiole, and root of N. sativa on solid Murashige and Skoog (MS) medium containing 2,4-D (1 mg/l) and kinetin (2.15 mg/l). TQ content of the alcoholic extracts was measured by HPLC. Total phenols were determined using Folin–Ciocalteu method and antioxidant power was estimated using FRAP tests. The mix glial cells, inflamed by lipopolysaccharide, were subjected to anti-inflammatory studies in the presence of various amounts of TQ and the alcoholic extracts. Viability of the cells and nitric oxide production were measured by MTT and Griess reagent, respectively. The leaf callus obtained the highest growth rate (115.4 mg/day) on MS medium containing 2,4-D (0.22 mg/l) and kinetin (2.15 mg/l). Analyses confirmed that TQ content of the callus of leaf was 12 times higher than that measured in the seeds extract. However, it decreased as the calli aged. Decrease in the TQ content of the callus was accompanied with an increase in its phenolic content and antioxidant ability. Studies on the inflamed rat mix glial cells revealed significant reduction in the nitric oxide production in the presence of 0.2 to 1.6 mg/ml of callus extract and 1.25 to 20 μl/ml of the seed extracts. However, the extent of the effects is modified assumingly due to the presence of the other existing substances in the extracts.     

SUMOylation mediates CtIP’s functions in DNA end resection and replication fork protection

Double-strand breaks and stalled replication forks are a significant threat to genomic stability that can lead to chromosomal rearrangements or cell death. The protein CtIP promotes DNA end resection, an early step in homologous recombination repair, and has been found to protect perturbed forks from excessive nucleolytic degradation. However, it remains unknown how CtIP’s function in fork protection is regulated. Here, we show that CtIP recruitment to sites of DNA damage and replication stress is impaired upon global inhibition of SUMOylation. We demonstrate that CtIP is a target for modification by SUMO-2 and that this occurs constitutively during S phase. The modification is dependent on the activities of cyclin-dependent kinases and the PI-3-kinase-related kinase ATR on CtIP’s carboxyl-terminal region, an interaction with the replication factor PCNA, and the E3 SUMO ligase PIAS4. We also identify residue K578 as a key residue that contributes to CtIP SUMOylation. Functionally, a CtIP mutant where K578 is substituted with a non-SUMOylatable arginine residue is defective in promoting DNA end resection, homologous recombination, and in protecting stalled replication forks from excessive nucleolytic degradation. Our results shed further light on the tightly coordinated regulation of CtIP by SUMOylation in the maintenance of genome stability.