Effects of the methanol extract of Ocimum gratissimum on cumen hydroperoxide–induced oxidative stress on rat liver tissue

The present study was conducted to evaluate the in vitro effects of the methanol extract of O.gratissimum (MEOG) on DPPH and liver homogenate. All the assays wi t h DPPH (2,2-diphenyl-1- picrylhydrazyl) including the radical scavenging assay, indicated that MEOG has a notice able effect on scavenging the free radicals. The phenolic content of the sample was determined using Folin-Ciocalteu reagent and it was found to be 55.28±5.24 mg gallic acid equivalents (GA)/g dry weight. There was a statistically significant correlation between the amount of phenolic compounds and antioxidant activity (r2 = 0.836, P < 0.05). A group was treated with the extract only to check whether this plant has any toxic effect of its own or produced any side effect when added to the liver homogenate. The results established the fact that this extract is safe to be used without any toxic or side effects. In the liver homogenate, the levels of reduced glutathione (GSH), catalase (CAT) and superoxide dismutase (SOD) were  significantly reduced (P < 0.05) in cumen hydroperoxide (CHP)-treated control group (CC), but the extract-treated groups (EX) did not show any significant difference with the normal control (NC), which clearly indicated that the extract could prevent the toxic effects of CHP. These results suggest that MEOG could protect the liver tissue from lipid peroxidation induced by CHP by its antioxidative effect, and hence prevent the deleterious effects of CHP- induced hepatotoxicity. © 2013 International Formulae Group. All rights reserved.Keywords: Ocimum gratissimum, phytochemicals, oxidative stress, reactive oxygen species, lipid peroxidatio

Peptide Bond Distortions from Planarity: New Insights from Quantum Mechanical Calculations and Peptide/Protein Crystal Structures

By combining quantum-mechanical analysis and statistical survey of peptide/protein structure databases we here report a thorough investigation of the conformational dependence of the geometry of peptide bond, the basic element of protein structures. Different peptide model systems have been studied by an integrated quantum mechanical approach, employing DFT, MP2 and CCSD(T) calculations, both in aqueous solution and in the gas phase. Also in absence of inter-residue interactions, small distortions from the planarity are more a rule than an exception, and they are mainly determined by the backbone ψ dihedral angle. These indications are fully corroborated by a statistical survey of accurate protein/peptide structures. Orbital analysis shows that orbital interactions between the σ system of Cα substituents and the π system of the amide bond are crucial for the modulation of peptide bond distortions. Our study thus indicates that, although long-range inter-molecular interactions can obviously affect the peptide planarity, their influence is statistically averaged. Therefore, the variability of peptide bond geometry in proteins is remarkably reproduced by extremely simplified systems since local factors are the main driving force of these observed trends. The implications of the present findings for protein structure determination, validation and prediction are also discussed

Short-Lived Trace Gases in the Surface Ocean and the Atmosphere

The two-way exchange of trace gases between the ocean and the atmosphere is important for both the chemistry and physics of the atmosphere and the biogeochemistry of the oceans, including the global cycling of elements. Here we review these exchanges and their importance for a range of gases whose lifetimes are generally short compared to the main greenhouse gases and which are, in most cases, more reactive than them. Gases considered include sulphur and related compounds, organohalogens, non-methane hydrocarbons, ozone, ammonia and related compounds, hydrogen and carbon monoxide. Finally, we stress the interactivity of the system, the importance of process understanding for modeling, the need for more extensive field measurements and their better seasonal coverage, the importance of inter-calibration exercises and finally the need to show the importance of air-sea exchanges for global cycling and how the field fits into the broader context of Earth System Science