http://blogs.najah.edu/author/iyadali An-Najah Blogs :: Iyad Ali en-us Sat, 27 Apr 2024 04:14:31 IDT Sat, 27 Apr 2024 04:14:31 IDT [email protected] [email protected] http://blogs.najah.edu/staff/iyadali/article/Photoilluminated-riboflavinriboflavin-CuII-inactivates-trypsin-CuII-tilts-the-balancePublished ArticlesIndian J Biochem Biophys 2006 Oct;435:312-8 Photoilluminated riboflavinriboflavin-CuII inactivates trypsin: CuII tilts the balance Husain E Fatima RA Ali IA Naseem I Department of Biochemistry Faculty of Life Sciences Aligarh Muslim University Aligarh 202 002 UP India Abstract Riboflavin RF upon irradiation with fluorescent light generates reactive oxygen species like superoxide anion singlet and triplet oxygen flavin radicals and substantial amounts of hydrogen peroxide H2O2 H2O2 can freely penetrate cell membrane and react with a transition metal ion like Cull generating hydroxyl radical via the modified metal-catalyzed Haber-Weiss reaction Earlier it was reported that trypsin-chymotrypsin mixture served as an indirect antioxidant and decreased free radical generation Thus in the present study we used photoilluminated RF as a source of ROS to investigate the effect of free radicals on the activity of trypsin We also compared the damaging effect of photoilluminated RF and RF-Cull system using trypsin as a target molecule RF caused fragmentation of trypsin and the effect was further enhanced when CuII was added to the reaction Results obtained with various ROS scavengers suggested that superoxide radical singlet and triplet oxygen were predominantly responsible for trypsin damage caused by photoilluminated RF On the other hand when Cull was added to the reaction hydroxyl radical was mainly responsible for trypsin damage A mechanism of generation of various ROS in the reaction is also proposed Trypsin did not show any antioxidant effect with RF alone or with RF-CuII combination http://blogs.najah.edu/staff/iyadali/article/Photodynamic-inactivation-of-trypsin-by-the-aminophylline-riboflavin-system-involvement-of-hydroxyl-radicalPublished ArticlesMed Sci Monit 2006 Aug;128:BR283-9 Epub 2006 Jul 12 Photodynamic inactivation of trypsin by the aminophylline-riboflavin system: involvement of hydroxyl radical Hasan N Ali I Naseem I Department of Biochemistry Faculty of Medicine JN Medical College Aligarh Muslim University Aligarh India nazarulhasan@rediffmailcom Abstract BACKGROUND: Riboflavin finds ubiquitous occurrence in plants and animals and functions as a coenzyme participating in various oxidation-reduction reactions during the course of metabolism Photosensitized riboflavin generates reactive oxygen species ROS Aminophylline is an antiasthmatic drug and a known phosphodiesterase inhibitor In this study we examined the effect of photoilluminated riboflavin on aminophylline using trypsin as the target molecule MATERIALMETHODS: The possible loss of trypsin activity due to autolysis was assayed after incubation in fluorescent light Changes in trypsin activity caused by photoilluminated riboflavin alone and with aminophylline were monitored as functions of concentration and time These effects were also analyzed by SDS-PAGE to visualize protein degradation Spectra of riboflavin alone and with aminophylline under different conditions were taken to monitor the structural changes for elucidating the possible reaction mechanism involved Free radical scavengers were also included in some experiments RESULTS: Aminophylline alone is not known to posses any photosensitizing characteristics However in the presence of riboflavin and fluorescent light aminophylline caused inactivation and fragmentation of trypsin This fragmentation was found to be concentration dependent and was mediated by ROS In all cases thiourea a scavenger of hydroxyl radicals was most effective in scavenging the damaging effect of the riboflavin-aminophylline combination CONCLUSIONS: Based on our results we suggest that photoilluminated riboflavin generates the singlet and triplet excited states that upon energy transfer generate 1O2 and 3O2 oxygen These activated oxygen species probably attack aminophylline leading to its oxidation generating hydroxyl radicals which presumably cause inactivation and fragmentation of trypsinhttp://blogs.najah.edu/staff/iyadali/article/Hemolysis-of-human-red-blood-cells-by-riboflavin-CuII-system-enhancement-by-azidePublished ArticlesBiochemistry Mosc 2005 Sep;709:1011-4 Hemolysis of human red blood cells by riboflavin-CuII system: enhancement by azide Ali I Sakhnini N Naseem I Faculty of Pharmacy Applied Science University Amman Jordan iyad74@yahoocom Abstract Photoactivated riboflavin in the presence of CuII generates reactive oxygen species ROS which can hemolyze human red blood cells RBC In the present work we examined the effect of sodium azide NaN3 on RBC in the presence of riboflavin and CuII The addition of NaN3 to the riboflavin-CuII system enhanced K loss and hemolysis The extent of K loss and hemolysis were time and concentration dependent Bathocuproine a CuI-sequestering agent inhibited the hemolysis completely Among various free radical scavengers used to identify the major ROS involved in the reaction thiourea was found to be the most effective scavenger Thiourea caused almost 85 inhibition of hemolysis suggesting that OH is the major ROS involved in the reaction Using spectral studies and other observations we propose that when NaN3 is added to the riboflavin-CuII system it inhibits the photodegradation of riboflavin resulting in increased OH generation Also the possibility of azide radical formation and its involvement in the reaction could not be ruled out http://blogs.najah.edu/staff/iyadali/article/Synthesis-of-a-novel-b-Lactamase-hydrolysis-resistant-penicillin-analogPublished ArticlesNina Sakhnini Iyad Ali and Samar Khater Synthesis of a novel b-Lactamase hydrolysis resistant penicillin analog Saudi Pharmaceutical Journal 2005 13 83-88 Saudi Arabiahttp://blogs.najah.edu/staff/iyadali/article/The-effect-of-riboflavin-CuII-system-on-lipid-peroxidation-of-human-red-blood-cellsPublished ArticlesIyad Ali and Imrana Naseem The effect of riboflavin-CuII system on lipid peroxidation of human red blood cells Arab Journal of Pharmaceutical Sciences 2005 2 11-20 Damascushttp://blogs.najah.edu/staff/iyadali/article/Hemolysis-of-human-red-blood-cells-by-combination-of-riboflavin-and-aminophyllinePublished ArticlesLife Sci 2002 Mar 15;7017:2013-22 Hemolysis of human red blood cells by combination of riboflavin and aminophylline Ali L Naseem I Department of Biochemistry Faculty of Life Sciences Aligarh Muslim University India iyad74@lycoscom Abstract The effect of aminophylline on human red blood cells RBC has been studied Under in vitro condition aminophylline alone does not hemolyse RBC However in the presence of riboflavin and visible light aminophylline causes hemolysis of RBC This hemolysis depends on the concentration of both riboflavin and aminophylline Using different free radical scavengers we show that RBC hemolysis is caused by reactive oxygen species Studies using bovine serum albumin show that riboflavin-aminophylline combination can also cause protein degradation in vitro PMID: 12148693 [PubMed - indexed for MEDLINE]http://blogs.najah.edu/staff/iyadali/article/Hemolysis-of-human-red-blood-cells-by-riboflavin-CuII-systemPublished ArticlesBiochim Biophys Acta 2000 Oct 18;15232-3:225-9 Hemolysis of human red blood cells by riboflavin-CuII system Ali I Gatasheh MK Naseem I Department of Biochemistry Faculty of Life Sciences Aligarh Muslim University 202002 Aligarh India iyad74@mailcitycom Abstract The photodynamic action of riboflavin is generally considered to involve the generation of reactive oxygen species whose production is enhanced when CuII is present in the reaction In the present study we report that photoactivated riboflavin causes K loss from fresh human red blood cells RBC in a time dependent manner Addition of CuII further enhances the K loss and also leads to significant hemolysis Riboflavin in a 2:1 stoichiometry with CuII leads to maximum K loss and up to 45 hemolysis Bathocuproine a specific CuI-sequestering agent when present in the reaction inhibits the hemolysis completely Free radical scavengers like superoxide dismutase potassium iodide and mannitol inhibited the hemolysis up to 55 or more However thiourea was the most effective scavenger showing 90 inhibition These results suggest that K leakage and hemolysis of human RBC are basically free radical mediated reactions