Seasonal changes of two biomarkers of oxidative stress (LDH,MDA) in the edible mollusc Donax trunculus (Mollusca: Bivalvia) from the Gulf of Annaba (Algeria): correlation with carbohydrate and lipid contents

The aim of the study was to determine seasonal variations of two biomarkers of oxidative stress, lactate dehydrogenase (LDH) and malondialdehyde (MDA), and their correlation with lipid-carbohydrate metabolism in the edible bivalve Donax trunculus. The samples were collected during the four seasons in 2014 at two sites in the Gulf of Annaba (northeast of Algeria): El Battah, which is some distance from any source of pollution, is considered a relatively clean site, while Sidi Salem is a site exposed to various sources of industrial, urban and harbour pollution. The results show a significant decrease in LDH activity in Sidi Salem D. trunculus compared with those at El Battah. Moreover, carbohydrate levels increased significantly in Sidi Salem. The MDA rate increased significantly in Sidi Salem relative to El Battah, while the amounts of lipid showed a significant decrease. The lipid and carbohydrate metabolism was negatively correlated with LDH and MDA. This difference between the two sites was observed for all seasons, with more effect in spring and summer. The results obtained showed that under stressful conditions due to anthropogenic factors, some physiological processes of D. trunculus can be affected. Thus, D. trunculus appears to be a suitable sentinel species for the assessment of ecotoxicological risk in the Gulf of Annaba.     

Anti-Alzheimer's Activity of Polyphenolic Stilbene-Rich Acetone Fraction of the Oil-Removed Seeds of Passiflora edulis: in Vivo and in Silico Studies

The stilbene-rich acetone fraction in high yield (6.6 %, PEAS) of Passiflora edulis Sims was prepared and evaluated for neuroprotective activity in murine Alzheimer's disease model induced by aluminum chloride and D-galactose. The phytochemical and HPLC-DAD-MS analysis of the polyphenolic stilbene-rich acetone fraction showed that it contained different stilbenes including trans-piceatannol, scirpusins A−B and cassigarol E. The total phenolic content (TPC) of PEAS was 413.87±1.71 mg GAE eqv/g. The neuroprotective activity of PEAS is typically presented in the Morris water maze-reference Spatial Memory test, where the Alzheimer's mice treated at 100 mg/kg (Alz-ED1) and 200 mg/kg (Alz-ED2) spent less than 47 % and 66 % of the time, respectively, than the Alzheimer's model mice (Alz). Two simple stilbenes, trans-piceatannol and trans-resveratrol, showed selectively inhibitory activity in silico against acetylcholinesterase (AChE). Two stilbene dimers, cassigarol E and scirpusin A, exhibited low nanomolar inhibitory potential against AChE and butyrylcholinesterase (BChE), significantly lower than those of the positive control, donepezil and tacrine. These findings suggest that the stilbenes from P. edulis seeds, particularly the stilbene dimers, warrant further investigation as potential neuroprotective candidates in the prevention of cognitive deficits associated with Alzheimer's disease.     

Cytotoxic sesquiterpenoids from Winteraceae of Caledonian rainforest

One secobutanolide, two butanolides and six drimane sesquiterpenoids were isolated from the bark and leaves of Zygogynum pancheri and Zygogynum acsmithii (Winteraceae) along with six known drimanes, isodrimanial, 1β-O-p-methoxy-E-cinnamoyl-bemadienolide, 7-ketoisodrimenin, drimenin, polygodial and 1β-E-cinnamoyl-6α-hydroxypolygodial. Their structures were elucidated through analysis of spectroscopic data. Drimane sesquiterpenoids with a dialdehyde function exhibited significant inhibitory activities in the in vitro cytotoxic assays against KB, HL60 and HCT116 cancer cell lines.     

Comparison of abacavir-specific effector and proliferating functions of CD8 T cells in abacavir-treated HIV-1 patients

Susceptibility to abacavir hypersensitivity (ABH) in HIV-1-positive patients is strongly linked to the carriage of HLA-B*57:01 and the potential mechanism includes drug-specific activation of cytokine producing CD8 T cells exclusively in individuals carrying HLA-B*57:01. Here, we report a detailed characterization of abacavir-induced functional response of CD8 T cells in HLA-B*57:01^pos individuals. Peripheral blood mononuclear cells (PBMNCs) from HLA-B*57:01^posABH^pos and HLA-B*57:01^negABH^neg individuals were stimulated with abacavir. Multicolor flow cytometry was performed to assess the cytokine (IFNγ) production and degranulation (CD107a expression) after 6–18 hr culture and to enumerate proliferating CD4/CD8 T cells by culturing carboxyfluorescein diacetate succinimidyl ester-loaded PBMNCs for 7 days. CD8 T cells from HLA-B*57:01^posABH^pos individuals were multifunctional: proliferating, IFNγ producing, degranulating (CD107a^pos), and both degranulating and IFNγ producing (CD107a^posIFNγ^pos). Degranulating CD8 T cells in general and both degranulating and IFNγ producing CD8 T cells in particular dominated abacavir-specific immune response. All functional responses were partially blocked by addition of HLA-B*57:01-reactive Bw4 mAb, but not by non-HLA-B*57:01-reactive Bw6 mAb. In conclusion, the study demonstrates that abacavir-specific CD8 T-cell-restricted immune response in HLA-B*57:01^posABH^pos HIV-1 patients has multiple effector and proliferating functions, where the primary effector response appears to be the release of cytolytic granules. The findings have implications for immunotherapy of HLA-related drug hypersensitivities.     

Chemical Composition and in Vitro Antioxidant,Anti-Alzheimer,Anti-Diabetic,Anti-Tyrosinase,and Antimicrobial Properties of Essential Oils and Extracts Derived from Various Parts of the Algerian Calendula Suffruticosa Vahlsubsp. boissieri Lanza

Calendula suffruticosa Vahl subsp. boissieri Lanza is well-known for its medicinal properties in northeastern Algeria. As far as literature has been able to prove, no study has attempted to make a phytochemical or biological activity evaluation (antioxidants, enzyme inhibitors and antimicrobial potential). This work intends to evaluate, for the first time, the chemical constituents and study the previously mentioned biological activities of C. suffruticosa boissieri essential oil and different sections (flowers, leaves, roots) as well as the effect of changing the solvent (ethanol 70 %) and (methanol 70 %) on these activities. The essential oil of aerial parts of this plant was investigated using GC/MS, and 45 compounds were discovered, accounting for 98.01 % of the essential oil, including 23 monoterpenes, 6 sesquiterpenes, 12 diterpenes, 1 coumarin, 3 alkanes, methyl-cyclohexane (23.73 %), limonene (25.02 %), and o-cymene (13.20 %). Five methods were used to study the antioxidant activity (ABTS, DPPH, CUPRAC, reducing power, and β-carotene bleaching assay), where the results were impressive, especially for the essential oil. In addition, the hydroethanolic solvent (70 %) was found to be the most effective solvent for extraction in general compared to the hydromethanolic solvent (70 %). The extracts and essential oils of C. suffruticosa boissieri also showed a strong inhibiting ability against cholinesterase, tyrosinase, anti-α-amylase, α-glucosidase, and antimicrobials, a very valuable antioxidant, which is a real discovery. Based on these results, it can be said that this plant has important biological activities, so it can be used in the phytotherapy, food, or pharmaceutical sectors.     

Chaotic genetic patchiness in the pelagic teleost fish Sardina pilchardus across the Siculo-Tunisian Strait

ABSTRACT

This investigation aims at assessing patterns of spatial genetic structure of the teleost fish Sardina pilchardus across the Siculo-Tunisian Strait (a well-known discontinuous biogeographic area) and delineating putative genetic stocks within the species. For this purpose, a total of 180 specimens, collected from 11 locations stretching across the western and eastern Mediterranean coasts of Tunisia, were analysed genetically by means of 18 nuclear allozyme loci. The outcome of this study revealed strong genetic differentiation among populations, with the marked genetic distinctiveness of the central Tunisian population at Mahdia. Despite the delineation of seven well-defined genetic groups, no significant correlation was found between genetic and geographic distances. Besides, the recorded population subdivision did not align with biogeographic boundaries, suggesting the presence of chaotic genetic patchiness. Recent genetic bottlenecks were evidenced in S. pilchardus populations. Patchy migration patterns were recorded among the examined pairs of sardine populations. Among the recorded 16 polymorphic loci, GPI-2 and SOD appeared to be subject to natural selection. Patterns of population genetic differentiation and structuring were not found to be driven by outlier loci that appeared to be under selection. Furthermore, the detected neutral GPI-1 locus was found to be responsible for most of the genetic variation among identified genetic clusters. Hence, natural selection cannot cause the detected genetic heterogeneity among sardine samples. Different explanations to the origin of chaotic genetic patterns, observed within S. pilchardus, were discussed.