Mohamed A. Dkhil

Bio: Mohamed A. Dkhil is an academic researcher from Helwan University. The author has contributed to research in topics: Oxidative stress & Plasmodium chabaudi. The author has an hindex of 29, co-authored 194 publications receiving 3233 citations. Previous affiliations of Mohamed A. Dkhil include King Saud University & Boehringer Ingelheim.

Bioaccumulation of some heavy metals in tilapia fish relevant to their concentration in water and sediment of Wadi Hanifah, Saudi Arabia

Abstract: Concentrations of some heavy metals (Pb, Cd, Hg, Cu and Cr) were determined in water, sediment and tissues of tilapia fish collected from Wadi Hanifah during summer 2010. The concentrations of the heavy metal in water were within the international permissible level. Cu had the highest accumulating level in fish whilst Hg had the lowest. The transfer factors of all metals in fish from water were greater than those from sediments. This led to the conclusion that fish bioaccumulation with these metals was from water. Heavy metals under study in the edible parts of tilapia were within the safety permissible level for human use.

Antioxidant effect of purslane (Portulaca oleracea) and its mechanism of action

Abstract: Aqueous juice from purslane ( Portulaca oleracea ) was screened for its antioxidant activity in adult male Waster albino rats. The antioxidant activity was determined by measuring reduced glutathione, catalase, superoxide dismutase, glutathione reductase, glutathione-S-transferase and glutathione peroxidase, as well as the inhibition in lipid peroxidation, nitric oxide in liver, kidney and testis of rats. Liver and kidney function were also determined. Administered rats with aqueous juice of purslane, resulted in marked improvement in all studied parameters. On the basis of the above results, it can be concluded that purslane is a promising natural product, which could be useful for the prevention of cardiovascular, neurodegenerative and other chronic diseases caused by oxidative stress.

Anti-hyperglycemic activity of selenium nanoparticles in streptozotocin-induced diabetic rats

Abstract: The study was designed to investigate the anti-hyperglycemic activity of selenium nanoparticles (SeNPs) in streptozotocin-induced diabetic rats. Fifty-five mg/kg of streptozotocin was injected in rats to induce diabetes. Animals either treated with SeNPs alone or with insulin (6 U/kg) showed significantly decreased fasting blood glucose levels after 28 days of treatment. The serum insulin concentration in untreated diabetic animals was also enhanced by SeNPs. The results demonstrated that SeNPs could significantly decrease hepatic and renal function markers, total lipid, total cholesterol, triglyceride and low-density lipoprotein cholesterol levels, and glucose-6-phosphatase activity. At the same time, SeNPs increased malic enzyme, hexokinase and glucose-6-phosphate dehydrogenase activity, liver and kidney glycogen contents, and high-density lipoprotein cholesterol levels. In addition, SeNPs were able to prevent the histological injury in the hepatic and renal tissues of rats. However, insulin injection also exhibited a significant improvement in diabetic animals after 28 days of treatment. This study suggests that SeNPs can alleviate hyperglycemia and hyperlipidemia in streptozotocin-induced diabetic rats, possibly by eliciting insulin-mimetic activity.

A new species

Abstract: We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

A Large Intergenic Noncoding RNA Induced by p53 Mediates Global Gene Repression in the p53 Response

Abstract: Recently, more than 1000 large intergenic noncoding RNAs (lincRNAs) have been reported. These RNAs are evolutionarily conserved in mammalian genomes and thus presumably function in diverse biological processes. Here, we report the identification of lincRNAs that are regulated by p53. One of these lincRNAs (lincRNA-p21) serves as a repressor in p53-dependent transcriptional responses. Inhibition of lincRNA-p21 affects the expression of hundreds of gene targets enriched for genes normally repressed by p53. The observed transcriptional repression by lincRNA-p21 is mediated through the physical association with hnRNP-K. This interaction is required for proper genomic localization of hnRNP-K at repressed genes and regulation of p53 mediates apoptosis. We propose a model whereby transcription factors activate lincRNAs that serve as key repressors by physically associating with repressive complexes and modulate their localization to sets of previously active genes.