Quercus ilex L.: How season,Plant Organ and Extraction Procedure Can Influence Chemistry and Bioactivities

Quercus species have a plethora of applications, either in wine and wood industries, in human and animal nutrition or in human health. In order to improve the knowledge on this genus, the aim of the present study was to correlate, for the first time, the phenolic composition of different Quercus ilex L. plant tissues (leaves in two maturation stages, acorns, teguments and cotyledons) and different extraction procedures with scavenging and anticholinesterase activities. The hydromethanolic and aqueous extracts obtained showed strong radical scavenging activity against DPPH, superoxide anion radical and nitric oxide radical, leaves exhibiting higher total phenolic content and revealing the best antioxidant properties, followed by tegument and acorns. Concerning the phenolic profile, fifteen compounds were identified and quantified by HPLC‐DAD, ranging from 1568.43 to 45,803.16 mg/kg dried extract. The results indicate that Q. ilex can be a source of strong antioxidant phenolic compounds with possible interest for food and pharmaceutical industries.     

Cloning of the pleiotropic T locus in soybean and two recessive alleles that differentially affect structure and expression of the encoded flavonoid 3' hydroxylase

Three loci (I, R, and T) control pigmentation of the seed coats in Glycine max and are genetically distinct from those controlling flower color. The T locus also controls color of the trichome hairs. We report the identification and isolation of a flavonoid 3' hydroxylase gene from G. max (GmF3'H) and the linkage of this gene to the T locus. This GmF3'H gene was highly expressed in early stages of seed coat development and was expressed at very low levels or not at all in other tissues. Evidence that the GmF3'H gene is linked to the T locus came from the occurrence of multiple RFLPs in lines with varying alleles of the T locus, as well as in a population of plants segregating at that locus. GmF3'H genomic and cDNA sequence analysis of color mutant lines with varying t alleles revealed a frameshift mutation in one of the alleles. In another line derived from a mutable genetic stock, the abundance of the mRNAs for GmF3'H was dramatically reduced. Isolation of the GmF3'H gene and its identification as the T locus will enable investigation of the pleiotropic effects of the T locus on cell wall integrity and its involvement in the regulation of the multiple branches of the flavonoid pathway in soybean.     

Functional over-expression of the Stm1 protein,a G-protein-coupled receptor,in Schizosaccharomyces pombe

We report here the first functional over-expression of the Stm1 protein, a G-protein-coupled receptor with seven-trans-membrane spanning regions, in a homologous expression system without internal modification of the open reading frame of Stm1. The entire coding sequence, except for the termination codon followed by a C-terminal His6 tag, has been cloned into the pREP1 vector. The functionally active Stm1-His6 was over-expressed in Schizosaccharomyces pombe under the control of the nmt1 (no message in thiamine) promoter. The expression after induction was 120 times as much as that of control before induction and it gave 500 ng protein/2 × 10⁷cells.     

Functionally significant mobile regions of Escherichia coli SecA ATPase identified by NMR

SecA, a 204-kDa homodimeric protein, is a major component of the cellular machinery that mediates the translocation of proteins across the Escherichia coli plasma membrane. SecA promotes translocation by nucleotide-modulated insertion and deinsertion into the cytoplasmic membrane once bound to both the signal sequence and portions of the mature domain of the preprotein. SecA is proposed to undergo major conformational changes during translocation. These conformational changes are accompanied by major rearrangements of SecA structural domains. To understand the interdomain rearrangements, we have examined SecA by NMR and identified regions that display narrow resonances indicating high mobility. The mobile regions of SecA have been assigned to a sequence from the second of two domains with nucleotide-binding folds (NBF-II; residues 564-579) and to the extreme C-terminal segment of SecA (residues 864-901), both of which are essential for preprotein translocation activity. Interactions with ligands suggest that the mobile regions are involved in functionally critical regulatory steps in SecA.     

The effects of maternal mild protein restriction on stroke incidence and blood pressure in stroke-prone spontaneously hypertensive rats (SHRSP)

The effect of maternal protein restriction during pregnancy on the offspring's blood pressure was assessed in stroke-prone spontaneously hypertensive rats (SHRSP) which are genetically predisposed to hypertension and stroke. After the confirmation of pregnancy, the control group was given a 20% casein diet, and the low-protein group was fed a 9% casein diet. After the confirmation of delivery, commercial feed was given to both of the groups. No differences were seen between the control and low-protein offspring in regard to body weight, blood pressure elevation, or life span. One percent saline solution was put in the control and low-protein groups after the age of 11 weeks. Blood pressure increased markedly in the low-protein group, on the blood pressure level in the low-protein group on week 2 after salt loading (242+/-6 mmHg) was significantly higher than that in the control group (223+/-9 mmHg; p<0.05). The survival duration was significantly shorter in the low-protein group (113+/-4 days) than in the control group (135+/-22 days; p<0.05). These results suggest that maternal protein malnutrition in SHRSP exerted a high salt sensitivity and a malignant influence on stroke incidence on offspring.     

Evaluation of a standardized F1 capsular antigen capture ELISA test kit for the rapid diagnosis of plague

Rapid detection of soluble F1 capsular antigen in serum, bubo fluid or urine of patients proved to be a valuable tool in the presumptive diagnosis of plague. We evaluated a F1 capsular antigen capture ELISA resembling a commercially available test kit. The minimal detectable concentration was 4 ng/ml. The specificity was 100% when investigating 47 sera from healthy Malagasy subjects and 98.4% when 365 sera from German blood donors were studied. Sensitivity was determined on sera (n=11) and buboes (n=18) from bacteriologically confirmed Malagasy plague patients. Sensitivity was 90.1% for serum and 100% for buboes. A standardized F1 capsular antigen capture ELISA test kit might be well suited for the early detection of plague particularly in non-endemic areas where clinical microbiological laboratories have only limited access to alternative techniques for rapid identification of Yersinia pestis.     

Cholesteryl ester transfer protein expression attenuates atherosclerosis in ovariectomized mice

Reduced estrogen levels result in loss of protection from coronary heart disease in postmenopausal women. Enhanced and diminished atherosclerosis have been associated with plasma levels of cholesteryl ester transfer protein (CETP); however, little is known about the role of CETP-ovarian hormone interactions in atherogenesis. We assessed the severity of diet-induced atherosclerosis in ovariectomized (OV) CETP transgenic mice crossbred with LDL receptor knockout mice. Compared with OV CETP expressing ((+)), OV CETP non-expressing ((-)) mice had higher plasma levels of total, VLDL-, LDL-, and HDL-cholesterol, as well as higher antibodies titers against oxidized LDL. The mean aortic lesion area was 2-fold larger in OV CETP(-) than in OV CETP(+) mice (147 +/- 90 vs. 73 +/- 42 x 10(3) micro m(2), respectively). Estrogen therapy in OV mice blunted the CETP dependent differences in plasma lipoproteins, oxLDL antibodies, and atherosclerosis severity. Macrophages from OV CETP(+) mice took up less labeled cholesteryl ether (CEt) from acetyl-LDL than macrophages from OV CETP(-) mice. Estrogen replacement induced a further reduction in CEt uptake and an elevation in HDL mediated cholesterol efflux from pre-loaded OV CETP(+) as compared with OV CETP(-) macrophages. These findings support the proposed anti-atherogenic role of CETP in specific metabolic settings.