Ex-vivo antihypertensive and calcium channel blocking activity of Androsace foliosa n-hexane leaves fraction on isolated rabbit aorta.

Hypertension is persistent elevation in blood pressure for 3-4 weeks. Estimated global prevalence of hypertension suggested that by the Year 2025 (29%) of adult worldwide are suffering from hypertension (1.56 billion). Hypertension complications are hemorrhage, atherosclerosis, renal artery stenosis, angina pectoris end organ damage, cardiomyopathy, myocardial infarction and retinopathy. Along with other drug class Calcium channel blocker are also used for the treatment of hypertension. In this study the possible action of the n-hexane leaves fraction of the Androsace foliosa on isolated rabbit aorta was examined. Antihypertensive activity was examined in the existence of standard agonist like phenylephrine and antagonist like Verapamil. Phenylephrine (PE 1µM) high K+ was used to steady the tissue materials. Additionally to observe the calcium channel blocking effect the tissues were treated with n-hexane segment of A. foliosa leaves. Aortic tissues were treated 4-5intervals with Ca+2- free preparation earlier to control calcium reaction curve (CRCs). Verapamil is utilized as standard calcium channel inhibitory mediator and is used as an antagonist. The Af. n-hexane leaves fraction completely inhibited the precontractions induced by Phenylephrine (1µM) and K+ (80 mM) precontractions, with EC50 standards of 1.0mM (0.3-1.0mg/mL) and 4.90mM (1-3mg/mL), respectively. Androsace foliosa n-hexane leaves fraction was tested for calcium channel inhibitory effect on isolated rabbit aorta. A. foliosa n- hexane leaves segment at the dosage of 1mg/mL block the calcium channel approximately (35±5%). Consequence indicates that A. foliosa n-hexane leaves segment block calcium channel in the similar manner as compared to the standard calcium channel blocker drug (verapamil).

Phytochemical analysis and hepatoprotective effect of polyherbal formulation on CCl4 induced hepatotoxicity in mice.

The potent phytotherapeutic modalities against the hepatotoxicity have motivated us to explore numerous plants and polyherbal preparations because conventional drug discovery is more expensive and tedious. So, this study was conducted to evaluate the hepatoprotective potential of a polyherbal formulation (PHF), comprising of Solanum nigrum, Silybum marianum, Atrmesia absinthium, Achillea millifolium and Cichorium intybus against carbon tetrachloride(CCl4) induced hepatotoxicity in experimental rats. CCl4intoxicationinduced vacuole formation and fastdegeneration so selective liver enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), alkalinephosphatase (ALP) and total bilirubin in rat's plasma,as well as liver histological architecture, were used to evaluate the effect of herbal treatments with different doses (ranging 100-500 mg/kg) for two weeks. Statistical analysis showed that PHF significantly (P<.05) improved the level of liver enzymes as well as improve the liver architecture comparative to control groups. It could be concluded from current findings that PHF prepared from Solanum nigrum, Silybum marianum, Atrmesia absinthium, Achillea millifiloium and Cichorium intybus have some hepatoprotective activities.

Crystallization and preliminary crystallographic analysis of recombinant hyaluronate lyase from Streptococcus suis.

Hyaluronate lyase is an important surface enzyme of many streptococcal species. The enzyme degrades several biologically important connective tissue components, which facilitates the spreading of the bacteria throughout the host tissues and presumably provides energy and a carbon source for bacterial cells. Recombinant hyaluronate lyase was expressed in Escherichia coli and was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P222(1), with unit-cell parameters a = 58.08, b = 101.32, c = 103.47 Å and one molecule in the asymmetric unit. Diffraction data were collected to 2.50 Å resolution.

Crystallization and preliminary crystallographic analysis of recombinant immunoglobulin G-binding protein from Streptococcus suis.

Streptococcus suis, an important zoonotic pathogen, expresses immunoglobulin G-binding protein, which is thought to be helpful to the organism in eluding the host defence system. Recombinant IgG-binding protein expressed in Escherichia coli has been crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 38.98, b = 43.94, c = 78.17 A and one molecule in the asymmetric unit. Diffraction data were collected to 2.60 A resolution.

First glimpse of the peptide presentation by rhesus macaque MHC class I: crystal structures of Mamu-A*01 complexed with two immunogenic SIV epitopes and insights into CTL escape.

The infection of rhesus macaques (Macaca mulatta) by the SIV is the best animal model for studying HIV infection and for AIDS vaccine development. A prevalent MHC class I allele, Mamu-A*01, is known to correlate with containment of SIV, which has been extensively explored in studies of CTL-based vaccination concepts. We determined the crystal structures of Mamu-A*01 complexed with two immunodominant SIV epitopes: the nonamer CM9 of group-specific Ag (Gag, 181-189; CTPYDINQM) and the octamer TL8 of transcription activator (Tat, 28-35; TTPESANL). The overall structures of the two Mamu-A*01 complexes are similar to other MHC class I molecules. Both structures confirm the presence of an absolutely conserved proline anchor residue in the P3 position of the Ag, bound to a D pocket of the Mamu-A*01 H chain with optimal surface complementarity. Like other MHC/peptide complex structures, the P2 and C-terminal residues of the epitopes are also important for anchoring to the MHC molecule, whereas the middle residues form an arch and their side chains are directed into solvent. These two structures reveal details of how Mamu-A*01 interacts with two well-studied epitopes at the atomic level. We discuss the structural basis of CTL escape, based on molecular models made possible by these two structures. The results we present in this study are most relevant for the rational design of Mamu-A*01-restricted CTL epitopes with improved binding, as a step toward development of AIDS vaccines.

Streptococcal toxic shock syndrome caused by Streptococcus suis serotype 2.

BACKGROUND: Streptococcus suis serotype 2 (S. suis 2, SS2) is a major zoonotic pathogen that causes only sporadic cases of meningitis and sepsis in humans. Most if not all cases of Streptococcal toxic shock syndrome (STSS) that have been well-documented to date were associated with the non-SS2 group A streptococcus (GAS). However, a recent large-scale outbreak of SS2 in Sichuan Province, China, appeared to be caused by more invasive deep-tissue infection with STSS, characterized by acute high fever, vascular collapse, hypotension, shock, and multiple organ failure. METHODS AND FINDINGS: We investigated this outbreak of SS2 infections in both human and pigs, which took place from July to August, 2005, through clinical observation and laboratory experiments. Clinical and pathological characterization of the human patients revealed the hallmarks of typical STSS, which to date had only been associated with GAS infection. Retrospectively, we found that this outbreak was very similar to an earlier outbreak in Jiangsu Province, China, in 1998. We isolated and analyzed 37 bacterial strains from human specimens and eight from pig specimens of the recent outbreak, as well as three human isolates and two pig isolates from the 1998 outbreak we had kept in our laboratory. The bacterial isolates were examined using light microscopy observation, pig infection experiments, multiplex-PCR assay, as well as restriction fragment length polymorphisms (RFLP) and multiple sequence alignment analyses. Multiple lines of evidence confirmed that highly virulent strains of SS2 were the causative agents of both outbreaks. CONCLUSIONS: We report, to our knowledge for the first time, two outbreaks of STSS caused by SS2, a non-GAS streptococcus. The 2005 outbreak was associated with 38 deaths out of 204 documented human cases; the 1998 outbreak with 14 deaths out of 25 reported human cases. Most of the fatal cases were characterized by STSS; some of them by meningitis or severe septicemia. The molecular mechanisms underlying these human STSS outbreaks in human beings remain unclear and an objective for further study.