Activity of plant extracts on the respiratory burst and the stress protein synthesis

Aqueous, methanol and dichloromethane extracts from Artemisia copa, Baccharis grisebachii, Baccharis incarum, Baccharis latifolia, Mutisia kurtzii and Pluchea sagittalis, plants used in the Traditional Medicine of South America, are studied for activity on the respiratory burst and the inducible heat shock protein of 72 kD (hsp72) synthesis. Activity on the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), as well as on hsp72 synthesis was measured by flow cytometry in human neutrophils. Cells were stimulated using hydrogen peroxide, phorbol-12-myristate-13-acetate (PMA) or formyl-methionyl-leucyl-phenylalanine (FMLP) for ROS generation, and sodium nitroprusside (SNP) or PMA in the presence of calmodulin inhibitor W-13 for RNS. The production of hsp72 was induced by heat, PMA, H2O2 and SNP. The best inhibitory activity was shown by the dichloromethane extracts of Baccharis grisebachii and Pluchea sagittalis that were active in all the assays. The aqueous extract of Pluchea sagittalis was also active in most assays. The aqueous extract from Mutisia kurtzii caused a clear increase of the hsp72 production and showed prooxidant activity.     

Telomeres:Linking stress and survival,ecology and evolution

Telomeres are protective structures at the ends of eukaryotic chromosomes. The loss of telomeres through cell division and oxidative stress is related to cellular aging, organismal growth and disease. In this way, telomeres link molecular and cellular mechanisms with organismal processes, and may explain variation in a number of important life-history traits. Here, we discuss how telomere biology relates to the study of physiological ecology and life history evolution. We emphasize current knowledge on how ...     

Analysis of post-translational modifications in Alzheimer's disease by mass spectrometry

The roles of post-translational modifications (PTMs) in the onset and progression of disease have been extensively studied for decades. More specifically, various PTMs have been the focus of research in Alzheimer's disease (AD). The two most discussed hallmarks of the disease, senile plaques and tau tangles, are the result of PTMs of the amyloidβ protein precursor (AβPP) and the microtubule stabilizing protein: tau. While these modifications have been characterized indirectly by biochemical-based methods, the primary shortcoming to this research can be linked to a lack of a thorough molecular-based means of qualitative and quantitative analysis of many of these modifications within transgenic animal, and human samples. In this review, we discuss the important proteins and their associated PTMs linked to AD and the ways in which mass spectrometry has and will be utilized to analyze them. We also comment on novel ways in which molecular-based mass spectrometry methods should be employed going forward to resolve the interconnections of the PTMs involvement in various stages of AD pathology (preclinical, mild cognitive impairment, advanced-stage AD).     

Endogenous opiates: 1986

This is the ninth installment of our annual review of research involving the endogenous opiate peptides. It is restricted to the non-analgesic and behavioral studies of the opiate peptides published in 1986. The specific topics this year include stress; tolerance and dependence; eating; drinking; gastrointestinal, renal, and hepatic processes; mental illness; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurological disorders; activity; sex, pregnancy, and development; and some other behaviors.     

Endotoxemia,vitamin D and premature biological ageing in Arab adults with different metabolic states

There are limited studies on the association of endotoxin, a potent mediator of gut-derived inflammation and telomere length (TL). We investigated (1) the influence of adiposity on endotoxin and TL amongst Saudi adults according to type 2 diabetes mellitus (T2DM) status and (2) the influence vitamin D may have on TL attrition. Anthropometric data and fasting blood samples were taken from 775 Saudi adults visiting different primary care centers in Riyadh [387 T2DM and 388 non-T2DM]. TL, derived from peripheral blood mononuclear cells, was analyzed by Quantitative real-time polymerase chain reaction and circulating endotoxin levels by Limulus Amebocyte Lysate assay. Subjects were stratified based on obesity and T2DM status. A significant lower TL was observed in the non-obese T2DM group as compared with their non-obese, non-T2DM counterparts (p = 0.002). Significant inverse associations between TL, endotoxin and endotoxin activity were observed in the cohort with obesity. Regression analysis showed that endotoxin was a significant predictor for TL in all subjects and even after stratification according to subgroups; with variances perceived in circulating TL stronger among non-T2DM obese (10%; p = 0.003) than non-T2DM non-obese (12%; p = 0.007). Also, in the non-T2DM group, TL and HDL-cholesterol predicted 29% of the variances perceived in 25(OH)D (p < 0.001). Taken together these findings show that circulating endotoxin and 25(OH)D are associated with premature biological ageing influenced by adiposity and metabolic state; suggesting future intervention studies to manipulate gut microbiome and or vitamin D levels may offer ways to mitigate premature TL attrition.     

Screening of rice cultivars for Cr-stress response by using the parameters of seed germination,morpho-physiological and antioxidant analysis

Rice is the most important crop for the majority of population across the world with sensitive behavior toward heavy metals such as chromium (Cr) in polluted regions. Although, there is no information on the Cr resistance phenotyping in rice. Herein, two different groups of rice cultivars (normal, and hybrid) were used, each group with 14 different rice cultivars. Firstly, seed germination analysis was conducted by evaluating various seed germination indices to identify the rice cultivars with greatest seed germination vigor. Furthermore, exposure of chromium (Cr) toxicity to 28 different rice varieties (NV1-NV14, HV1-HV14) caused noticeable plant biomass reduction. Subsequently, NV2, NV6, NV10, NV12, NV13 (normal type), HV1, HV4, HV8, and HV9 (hybrid types) were pragmatic as moderately sensitive varieties, while NV3, NV4, NV9, and NV14 (normal type), HV3, HV6, HV7, and HV13 were observed as moderately tolerant. Although, NV7, and HV10 were ranked most sensitive cultivars, and NV11, and HV14 were considered as most tolerant varieties as compared to the other rice (both groups) genotypes. Afterward, Cr induced reduction in chlorophyll pigments were significantly lesser in HV14 relative to NV11, NV7, and especially HV10, and as a result HV14 modulated the total soluble sugar level as well as reduced ROS accumulation, and MDA contents production by stimulating the antioxidant defense mechanism conspicuously which further reduced the electrolyte leakage as well. Our outcomes provide support to explore the Cr tolerance mechanism in cereal crops as well as knowledge about rice breeding with increased tolerance against Cr stress.     

Functional Activity of Blood Polymorphonuclear Leukocytes as an Oxidative Stress Biomarker in Human Subjects

In the present work, we studied the role of polymorphonuclear leukocytes (PMN) in aged individuals and coronary heart disease (CHD)-bearing patients, two physiopathological processes associated with overproduction of reactive oxygen species (ROS). The effects of antioxidant supplementation on the functional activity of PMN from CHD patients were also determined. The function of PMNs was evaluated by measuring of phagocytosis, killing activity, and ROS production. Luminol amplified chemiluminescence (CL) was used to estimate ROS production by stimulated PMNs. Total cholesterol and the LDL-cholesterol fraction from CHD patients were found to be higher than those recommended, returning to normal levels after antioxidant therapy. PMN CL of CHD patients was found to be higher than the associated control groups. Antioxidant therapy administrated to CHD patients lead to an increase in the killing activity accompanied by a decrease in PMN CL of these subjects. The study also showed that killing activity of PMN from human subjects over 60 years was significantly lower than the activity measured in younger subjects. PMN CL produced after stimulation was found to be positively correlated with the increasing age of human subjects (r = .946, p < .01).     

Differential role of microenvironment in microencapsulation for improved cell tolerance to stress

The effect of the microenvironment in alginate–chitosan–alginate (ACA) microcapsules with liquid core (LCM) and solid core (SCM) on the physiology and stress tolerance of Sacchromyces cerevisiae was studied. The suspended cells were used as control. Cells cultured in liquid core microcapsules showed a nearly twofold increase in the intracellular glycerol content, trehalose content, and the superoxide dismutase (SOD) activity, which are stress tolerance substances, while SCM did not cause the significant physiological variation. In accordance with the physiological modification after being challenged with osmotic stress (NaCl), oxidative stress (H₂O₂), ethanol stress, and heat shock stress, the cell survival in LCM was increased. However, SCM can only protect the cells from damaging under ethanol stress. Cells released from LCM were more resistant to hyperosmotic stress, oxidative stress, and heat shock stress than cells liberated from SCM. Based on reasonable analysis, a method was established to estimate the effect of microenvironment of LCM and SCM on the protection of cells against stress factors. It was found that the resistance of LCM to hyperosmotic stress, oxidative stress, and heat shock stress mainly depend on the domestication effect of LCM’s microenvironment. The physical barrier of LCM constituted by alginate–chitosan membrane and liquid alginate matrix separated the cells from the damage of oxidative stress and ethanol stress. The significant tolerance against ethanol stress of SCM attributed to the physical barrier consists of solid alginate–calcium matrix and alginate–chitosan membrane.     

Carrier subunit of plasma membrane transporter is required for oxidative folding of its helper subunit

We study the amino acid transport system b(0,+) as a model for folding, assembly, and early traffic of membrane protein complexes. System b(0,+) is made of two disulfide-linked membrane subunits: the carrier, b(0,+) amino acid transporter (b(0,+)AT), a polytopic protein, and the helper, related to b(0,+) amino acid transporter (rBAT), a type II glycoprotein. rBAT ectodomain mutants display folding/trafficking defects that lead to type I cystinuria. Here we show that, in the presence of b(0,+)AT, three disulfides were formed in the rBAT ectodomain. Disulfides Cys-242-Cys-273 and Cys-571-Cys-666 were essential for biogenesis. Cys-673-Cys-685 was dispensable, but the single mutants C673S, and C685S showed compromised stability and trafficking. Cys-242-Cys-273 likely was the first disulfide to form, and unpaired Cys-242 or Cys-273 disrupted oxidative folding. Strikingly, unassembled rBAT was found as an ensemble of different redox species, mainly monomeric. The ensemble did not change upon inhibition of rBAT degradation. Overall, these results indicated a b(0,+)AT-dependent oxidative folding of the rBAT ectodomain, with the initial and probably cotranslational formation of Cys-242-Cys-273, followed by the oxidation of Cys-571-Cys-666 and Cys-673-Cys-685, that was completed posttranslationally.