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.     

In vitro anti-inflammatory and wound healing properties of Andrographis echioides and Andrographis paniculata

Andrographis echioides (L.) is an annual herbaceous plant in the family Acanthaceae. Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Antioxidants are substances that can prevent or slow damage to cells caused by free radicals, unstable molecules that the body produces as a reaction to environmental and other pressures. They are sometimes called "free-radical scavengers. Therefore, it is of interest to analyse the anti-inflammatory and antioxidant properties of Andrographis echioides and Andrographis paniculata. Protease inhibitor activity was done by bovine serum albumin was added to 100µl of plant sample with increase in concentrations (100-500µg/ml). Invitro antioxidant activity was done by DPPH free radical scavenging assay. 200 µL of 0.1 mM DPPH prepared in methanol was added to 100 µL of the plant extract with increase in concentration. Based on the results from the present study, it can be concluded that A.echioides is found to be a good natural antioxidant source and A. paniculata is found to be a good anti-inflammatory source. However, both the plant A.echioides and A.paniculata have these properties. Data shows that both A.echioides and A. paniculata have potential anti-inflammatory and antioxidant activity which could be due to the presence of bioactive compounds present in the plant extracts.     

A review on hypo-cholesterolemic activity of Nigella sativa seeds and its extracts

Nigella sativa (N. sativa) (Family Ranunculaceae) is a popular therapeutic herb in many parts of the world. It is widely used in traditional medical systems such as Unani, Ayurveda and Siddha. Seeds and oil have a long history of folkloric use in many medicinal and culinary systems. The seeds of N. sativa have long been used to treat a variety of illnesses and disorders. Studies on N. sativa and its therapeutic potential have been investigated. This includes anti-diabetic, anticancer, immune-modulatory, analgesic, antimicrobial, anti-inflammatory, spasmolytic, bronchodilator, hepato-protective, renal protective, gastro-protective, antioxidant properties, and several others. Nigella sativa contains thymoquinone. This is a bioactive component of the essential oil with medicinal benefits. Therefore, it is of interest to report a comprehensive data on the therapeutic usefulness of N. sativa in hypo-cholesterolemic activity.     

Effect of Carica papaya on beta catenin and Wnt mRNA expression in human colon cancer (HT-29) cells in vitro

Colon cancer is the third most frequent cancer in humans. Carica papaya leaves are vegetable foods consumed by most people around the world; it has potential as an anticancer. Therefore it is of interest to investigate the effect of Carica papaya on beta catenin and Wnt mRNA expression in human colon cancer (HT-29) cells in vitro. Human Colon cancer cell line (HT-29) was purchased from the National Centre for Cell Sciences, Pune, India. Cell viability test was done by MTT assay. Gene expression analysis was done by Real Time-PCR. The obtained data were analyzed statistically by one-way analysis of variance and Duncan''s multiple range test with Graph Pad Prism version 5 to analyze the significance of individual variations among the control and experimental groups. The significance was considered at p<0.05 level in Duncan''s test. Carica papaya caused a marked increase in cell death in a dose dependent manner. At the end of 48 hours, maximum inhibition was at 300 and 400 µg/ml. Carica papaya has significantly reduced the mRNA expression of Wnt and beta catenin (p<0.05). Data showed that Carica papaya leaf extract has anticancer activity on Colon cancer cell lines (HT-29).