Effect of oxygenation on stem-cell therapy for myocardial infarction.

Stem-cell transplantation to treat acute myocardial infarction (MI) is gaining importance as a minimally invasive and potent therapy to replace akinetic scar tissue by viable myocardium. Our recent studies have shown that stem-cell transplantation marginally improves myocardial oxygenation in the infarct tissue leading to improvement in cardiac function. The aim of the present study was to determine the effect of hyperbaric oxygen (HBO) treatment on myocardial oxygenation and recovery of function in MI hearts. Fisher-344 rats were subjected to MI by permanently ligating the left-anterior-descending (LAD) coronary artery. The rats were then exposed to 100% O(2) at a pressure of 2 atmospheres for 90 minutes, and the exposure was repeated for 5 days a week for 2 weeks. Adult bone-marrow-derived rat mesenchymal stem cells (MSC, 5x105 cells) were mixed with OxySpin (LiNc- BuO, oxygen sensor) and implanted in the infarct and peri-infarct regions of the heart. M-mode ultrasound echocardiography was performed at baseline and at 2 weeks post-transplantation. The myocardial pO(2) in the MSC+HBO group (16.2±2.2 mmHg) was significantly higher when compared to untreated MI (3.8±1.9 mmHg) or MSC (9.8±2.3 mmHg) groups. In addition, there was a significant improvement in cardiac function, increased vessel density, and VEGF expression in MSC+HBO group compared to MSC group (p < 0.05). In conclusion, the results suggested a beneficial effect of HBO administration on stem-cell therapy for MI.

Antibacterial activity of silver nanoparticles (AgNps) synthesized by tea leaf extracts against pathogenic Vibrio harveyi and its protective efficacy on juvenile Feneropenaeus indicus.

AIMS: To determine the antibacterial potential of silver nanoparticles (AgNps) synthesized by tea leaf extract against Vibrio harveyi and its protective effect on juvenile Feneropenaeus indicus. METHODS AND RESULTS: AgNps were synthesized by a simple procedure using tea leaf extract as the reducing agent. Bacteriological tests were performed in Luria-Bertani medium on solid agar plates and in liquid systems supplemented with V. harveyi against different concentrations of AgNps. AgNps synthesized in the present study were shown to be effective against V. harveyi isolated from F. indicus. The combined results of long- and short-term treatment of AgNps synthesized by tea leaf extract showed a 71% reduction in accumulated mortality. CONCLUSIONS: The long-term administration of AgNps synthesized by tea leaf extracts at the concentration of 10 microg significantly reduced the mortalities in F. indicus from V. harveyi infections. SIGNIFICANCE AND IMPACT OF THE STUDY: The AgNps synthesized by tea leaf extract may be an alternative to antibiotics in controlling V. harveyi infections.

Antiviral activity of bis(2-methylheptyl)phthalate isolated from Pongamia pinnata leaves against White Spot Syndrome Virus of Penaeus monodon Fabricius.

White Spot Syndrome Virus (WSSV) is an extremely virulent, contagious, causative agent of the White spot syndrome of shrimp and causes high mortality and affects most of the commercially important cultured marine crustacean species globally. Oral administration of ethanolic extract and purified compound from the leaves of Pongamia pinnata, an indigenious Indian "medicinal plant" "has increased the survival of WSSV infected Penaeus monodon". Pelletized feed impregnated with ethanolic extract of the leaves of P. pinnata was fed to shrimp prior and after WSSV infection at 200 and 300 microg/g of body weight of shrimp/day. The survival rate for the WSSV-infected shrimp that were fed with 200 and 300 microg extract/g were 40% and 80%, respectively. The active WSSV antiviral compound 1 that was isolated from the leaves of P. pinnata was identified as bis(2-methylheptyl)phthalate. Thus, the present work revealed that oral administration of the crude and purified compound from the leaves of P. pinnata effectively inhibited WSSV pathogenesis and reduced the mortality of infected shrimp.