Hesperidin, a flavanone glycoside, on lipid peroxidation and antioxidant status in experimental myocardial ischemic rats

Myocardial infarction continues to be a leading cause of mortality world-wide. Novel therapies are needed to treat the myocardial ischemia. This study was undertaken to evaluate the cardioprotective role of hesperidin on isoproterenol-induced myocardial ischemia in rats. Myocardial ischemia was induced by subcutaneous injection of isoproterenol hydrochloride (85 mg/kg body weight), for two consecutive days. Isoproterenol-administered rats showed elevated levels of cardiac markers (aspartate transaminase, alanine transaminase, lactate dehydrogenase, creatine kinase, creatine kinase-MB, cardiac troponins T and I) when compared with control and hesperidin treatment groups (100, 200 and 400 mg/kg body weight). The serum levels of cardiac markers were significantly reduced at the doses of 200 mg and 400 mg. All further experiments were carried out at the 200 mg dose. Lipid peroxidation markers (thiobarbituric acid reactive substances, lipid hydroperoxides and conjugated dienes) were elevated significantly in the plasma and heart whereas non-enzymic antioxidants (vitamin C, vitamin E and reduced glutathione) were decreased significantly. Activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase and glutathione reductase declined significantly in the heart of ischemic rats. However, after hesperidin treatment, all the above parameters reverted to normal levels. This study demonstrated that the cardioprotective effect of hesperidin on ischemic rats could be due to its anti-lipid peroxidative and antioxidant properties.     

Molecular docking analysis of flavonoids with aldose reductase

Diabetes mellitus is a group of metabolic disorders that has risen to become the third most common cause in humans in recent years. The development of new bioactive substances from natural sources is a relatively new area. Flavonoids are believed to have a variety of beneficial properties in nature, including anti-inflammatory, antimicrobial, anticancer, antioxidant, neuroprotective, and anti-HIV properties. 15 naturally occurring flavonoids docked with the selected target aldose reductase. We report the optimal binding of Acumitin, Agathisflavone, Agehoustin B, and alpha-Toxicarol with aldose reductase for further consideration in drug discovery for T2DM.     

Identification of a CYP84 family of cytochrome P450-dependent mono-oxygenase genes in Brassica napus and perturbation of their expression for engineering sinapine reduction in the seeds

CYP84 is a recently identified family of cytochrome P450-dependent mono-oxygenases defined by a putative ferulate-5-hydroxylase (F5H) from Arabidopsis. Until recently F5H has been thought to catalyze the hydroxylation of ferulate to 5-OH ferulate en route to sinapic acid. Sinapine, a sinapate-derived ester in the seeds, is antinutritional and a target for elimination in canola meal. We have isolated three F5H-like genes (BNF5H1-3) from a cultivated Brassica napus, whose amphidiploid progenitor is considered to have arisen from a fusion of the diploids Brassica rapa and Brassica oleracea. Two cultivated varieties of the diploids were also found to contain BNF5H3 and additionally either BNF5H1 or BNF5H2, respectively. Whereas all three are >90% identical in their coding sequence, BNF5H1 and BNF5H2 are closer to each other than to BNF5H3. This and additional data suggest that the two groups of genes have diverged in an ancestor of the diploids. B. napus showed maximal F5H expression in the stems, least in the seeds, and subtle differences among the expression profiles of the three genes elsewhere. Transgenic B. napus with cauliflower mosaic virus 35S-antisense BNF5H contained up to 40% less sinapine, from 9.0 +/- 0.3 mg in the controls to 5.3 +/- 0.3 mg g(-1) seed. F5H from Arabidopsis and a similar enzyme from sweetgum (Liquidamber styraciflua) has recently been shown to have coniferaldehyde hydroxylase activity instead of F5H activity. Thus the supply of 5-OH coniferaldehyde or 5-OH ferulate has a bearing on sinapine accumulation in canola seeds.     

Comparative sequence analysis of acid sensitive/resistance proteins in Escherichia coli and Shigella flexneri

The molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. A preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in Escherichia coli and Shigella flexneri. Here we found the molecular evidence that proved the relationship between E. coli and S. flexneri. Multiple sequence alignment of the gadC coded acid sensitive antiporter showed many conserved residue patterns at regular intervals at the N-terminal region. It was observed that as the alignment approaches towards the C-terminal, the number of conserved residues decreases, indicating that the N-terminal region of this protein has much active role when compared to the carboxyl terminal. The motif, FHLVFFLLLGG, is well conserved within the entire gadC coded protein at the amino terminal. The motif is also partially conserved among other antiporters (which are not coded by gadC) but involved in acid sensitive/resistance mechanism. Phylogenetic cluster analysis proves the relationship of Escherichia coli and Shigella flexneri. The gadC coded proteins are converged as a clade and diverged from other antiporters belongs to the amino acid-polyamine-organocation (APC) superfamily.     

Deletion of the aceE gene (encoding a component of pyruvate dehydrogenase) attenuates Salmonella enterica serovar Enteritidis

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major food-borne pathogen. From a transposon insertion mutant library created previously using S. Enteritidis 10/02, one of the mutants was identified to have a 50% lethal dose (LD(50) ) at least 100 times that of the parental strain in young chicks, with an attenuation in a poorly studied gene encoding a component of pyruvate dehydrogenase, namely the aceE gene. Evaluation of the in vitro virulence characteristics of the ΔaceE∷kan mutant revealed that it was less able to invade epithelial cells, less resistant to reactive oxygen intermediate, less able to survive within a chicken macrophage cell line and had a retarded growth rate compared with the parental strain. Young chicks vaccinated with 2 × 10(9) CFU of the ΔaceE∷kan mutant were protected from the subsequent challenge of the parental strain, with the mutant colonized in the liver and spleen in a shorter time than the group infected with the parental strain. In addition, compared with the parental strain, the ΔaceE∷kan mutant did not cause persistent eggshell contamination of vaccinated hens.     

Tetrazine-trans-cyclooctene ligation for the rapid construction of integrin αvβ₃ targeted PET tracer based on a cyclic RGD peptide

Labeling biomolecules with ¹⁸F is usually done through coupling with prosthetic groups, which generally requires several time-consuming radiosynthetic steps resulting in low labeling yield. Recently, the tetrazine-trans-cyclooctene ligation has been introduced as a method of bioconjugation that proceeds with fast reaction rates without need for catalysis. Herein, we report the development of an extremely fast and efficient method for generating ¹⁸F labeled probes based on the tetrazine-trans-cyclooctene ligation. Starting with only 30 μg (78 μM) of a tetrazine-RGD conjugate and 2 mCi (5 μM) of ¹⁸F-trans-cyclooctene, the ¹⁸F labeled RGD peptide could be obtained in more than 90% yield within five minutes. The ¹⁸F labeled RGD peptide demonstrated prominent tumor uptake in vivo. The receptor specificity was confirmed by blocking experiments. These results successfully demonstrate that the tetrazine-trans-cyclooctene ligation serves as an efficient labeling method for PET probe construction.