Antimicrobial activity of allylic thiocyanates derived from the Morita-Baylis-Hillman reaction

Bacterial resistance to commonly used antibiotics has been recognized as a significant global health issue. In this study, we carried out the screening of a family of allylic thiocyanates for their action against a diversity of bacteria and fungi with a view to developing new antimicrobial agents. Allylic thiocyanates bearing halogenated aryl groups, which were readily obtained in two steps from the Morita-Baylis-Hillman adducts, showed moderate-to-high activity against selective pathogens, including a methicillin-resistant S. aureus (MRSA) strain. In particular cases, methyl (Z)-3-(2,4-dichlorophenyl)-2-(thiocyanomethyl)-2-propenoate exhibited antimicrobial activity comparable to the reference antibiotic Imipenem.

Sulforaphane Induces Antioxidative and Antiproliferative Responses by Generating Reactive Oxygen Species in Human Bronchial Epithelial BEAS-2B Cells

Sulforaphane (SFN) is a naturally occurring compound which is known to induce the phase II antioxidant genes via Nrf2 activation, although the underlying mechanism has not been fully elucidated. In this study, we investigated Nrf2 induction in response to SFN in human bronchial epithelial BEAS-2B cells and determined the signaling pathways involved in this process. SFN treatment reduced cell viability. Prior to cell death, intracellular reactive oxygen species (ROS) were generated at a high rate within a minute of commencing SFN treatment. Pretreatment with antioxidant N-acetylcysteine (NAC) blocked SFN-induced decrease in cell growth. Erk1/2 was activated within 30 min of SFN addition, whereas Akt phosphorylation did not significantly change until the first 8 hr after SFN treatment but then became substantially low until 48 hr. Inhibition of Erk1/2 phosphorylation attenuated SFN-induced loss of cell viability. Nrf2 protein levels in both nuclear and whole cell lysates were increased by SFN treatment, which was dependent on ROS production. Knockdown of Nrf2 with siRNA attenuated SFN-induced heme oxygenase-1 (HO-1) up-regulation. Induction of the Nrf2/HO-1 after SFN treatment was potently suppressed by pretreatment with NAC. Overall, our results indicate that SFN mediates antioxidative and antiproliferative responses by generating ROS in BEAS-2B cells.

Comparaive studies on antisickling properties of thiocyanate, tellurite and hydroxyurea

Thiocyanate, hydroxyurea and tellurite are among chemical agents being used as antisickling drugs and currently receiving attention for research. The antisickling properties of these drugs was investigated and compared in this study. Human sickle blood was incubated with the drugs in vitro at concentrations related to the dose used by patients in vivo. Haemoglobin function and specific aspects of the sickling process were then measured by employing standard methods used in screening potential antisickling agents. All the drugs significantly inhibited [P<0.05] sickling of deoxygenated sickle blood and formation of irreversibly sickled cell in a dose and time-dependent manner. Thiocyanate, hydroxyurea and tellurite inhibited sickling optimally at 20mM, 40mM and 50mM respectively. Thiocyanate and hydroxyurea prolonged sickle red blood cell life span as indicated in the significant decrease in haemolysis and osmotic fragility while tellurite increased these blood parameters. The three drugs also caused significant prolongation of delay time of haemoglobin S [HbS] polymerization while thiocyanate and hydroxyurea significantly increased [P<0.05] both solubility ratio and oxygen affinity of HbS. Results obtained in this study suggest that the three drugs have remarkable antisickling potential in vitro with thiocyanate being the most efficient followed by tellurite

Purification and some properties of carbonic anhydrase from Elephas trogontherii (Steppe elephant) bone.

Four isoenzymes of carbonic anhydrase (CA) were purified from Elephas Irogontherii (steppe elephant) bone (approx 0.3-0.5 million years old) from different locations (outer peripheral, cytosolic, inner peripheral and integral) using Sepharose 4B-L-tyrosine sulphanilamide affinity chromatography and their kinetics properties were investigated and compared with known CA isoenzymes. The purification degree of CAs was monitored by SDS-PAGE. Purification fold for outer peripheral, inner peripheral, cytosolic and integral CA was 395.6, 652.8, 1091 and 429.3 and the molecular mass (as determined by gel filtration chromatography) was 37, 36, 35, and 39 kDa, respectively. The optimal temperature for isozymes was 10-20, 30, 30 and 60 degrees C and optimal pH- was between 7.5-11, 7.5-10, 7.5-10 and 7.5 respectively. K(m) values (at optimum pH and 20 degrees C) for p-nitrophenyl acetate as substrate were 4.83, 6.80, 4.525 and 3.86 mM and the Vmax values for the same substrate were 0.00097, 0.0149, 0.00249 and 0.00072 micromol/L*min, respectively. I50 values of isoenzymes for the inhibitors of CA - sulphanilamide, KSCN, acetazolamide and NaN3 were also determined.

Distribution of hepatitis C virus genotypes in patients with chronic hepatitis C infection in India.

BACKGROUND & OBJECTIVES: Hepatitis C virus (HCV), an important cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma, shows a considerable genetic heterogeneity among hepatitis C virus isolates from all over the world. At least six main groups of sequence variants are recognized. The natural history of disease and response to treatment may be related to the genotype of HCV in a particular patient. Antigenic differences between genotypes also have implications for optimal design of serological sequencing and confirmatory assays for HCV. The present study was undertaken with the objective to find out various genotypes of hepatitis C virus prevalent in Indian patients with chronic hepatitis C infection. METHODS: Thirty six consecutive newly diagnosed patients with chronic hepatitis C infection were included in the study. HCV RNA was extracted from the serum by standard guanidinium thiocyanate method. Following reverse transcription and amplification, the HCV genotypes were determined by line probe assay (INNO-LiPA HCV II). RESULTS: Of the 36 patients, genotype 3 was found in 24 (66.6%). Of these 24 patients, 3a was seen in 5 patients (13.8%), 3b in two (5.5%) and mixed subtype 3a and 3b in 17 patients (47.2%). Genotype 1 was found in 5 patients (13.8%), with 1b in 1 and 1a in rest four cases. Two patients (5.5%) were infected with genotype 2 (subtype 2a and mixed subtype 2a, 2b respectively). One (2.7%) was infected with genotype 4 (4a). Mixed genotype infection was found in 4 patients (11.1%). INTERPRETATION & CONCLUSION: The present findings showed that genotype 3 of hepatitis C virus was the most prevalent genotype in patients with chronic hepatitis C in this part of India.

Potentialization of the lactoperoxidase system for preservation of raw milk in the tropics

Se aumentó la capacidad antimicrobiana del sistema lactoperoxidas, mediante la adición de tiocianato y peróxido de hidrógeno en cantidades mayores a las sugeridas por otros autores. Los resultados de laboratorio y las pruebas de campo revelaron que por otros autoes. Los resultados de laboratorio y las pruebas de campo revelaron que el sistema potencializado pudo preservar leches de baja calidad microbiológica, a temperaturas "tropicales" por períodos más largos que al usarlo como se recomienda en la literatura. Se pudo conservar leches a 20-C por más de un día, sin menoscabo de su calidad general. A 36-C, las leches no acusaron desarrollo de acidez durante el término de 10 horas. Las pruebas realizadas en condiciones reales de recolección y transporte validaron los resultados de laboratorio. Se logró así probar que el sistema lactoperoxidasa es viable de uso en la práctica, y que su poder bactericida/bacteriostático sobre la flora deterioradora de la leche puede aumentarse a fin de superar las condiciones especialmente adversas que involucra el menejo de la leche en los trópicos