Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Abdulrahman L. Al-Malki is active.

Publication


Featured researches published by Abdulrahman L. Al-Malki.


BioMed Research International | 2015

The Antidiabetic Effect of Low Doses of Moringa oleifera Lam. Seeds on Streptozotocin Induced Diabetes and Diabetic Nephropathy in Male Rats

Abdulrahman L. Al-Malki; Haddad A. El Rabey

The antidiabetic activity of two low doses of Moringa seed powder (50 and 100 mg/kg body weight, in the diet) on streptozotocin (STZ) induced diabetes male rats was investigated. Forty rats were divided into four groups. The diabetic positive control (STZ treated) group showed increased lipid peroxide, increased IL-6, and decreased antioxidant enzyme in the serum and kidney tissue homogenate compared with that of the negative control group. Immunoglobulins (IgA, IgG), fasting blood sugar, and glycosylated hemoglobin (HbA1c) were also increased as a result of diabetes in G2 rats. Moreover albumin was decreased, and liver enzymes and α-amylase were not affected. In addition, the renal functions and potassium and sodium levels in G2 were increased as a sign of diabetic nephropathy. Urine analysis showed also glucosuria and increased potassium, sodium, creatinine, uric acid, and albumin levels. Kidney and pancreas tissues showed also pathological alteration compared to the negative control group. Treating the diabetic rats with 50 or 100 mg Moringa seeds powder/kg body weight in G3 and G4, respectively, ameliorated the levels of all these parameters approaching the negative control values and restored the normal histology of both kidney and pancreas compared with that of the diabetic positive control group.


Diabetology & Metabolic Syndrome | 2012

Effect of novel water soluble curcumin derivative on experimental type- 1 diabetes mellitus (short term study)

Mohamed F. El-Asmar; Ibrahim N El-Ibrashy; Ameen M Rezq; Abdulrahman L. Al-Malki; Mohamed Abdel Aziz Wassef; Hanan Fouad; Hanan H. Ahmed; Fatma M. Taha; Amira A. Hassouna; Heba Morsi

BackgroundDiabetes mellitus type 1 is an autoimmune disorder caused by lymphocytic infiltration and beta cells destruction. Curcumin has been identified as a potent inducer of heme-oxygenase-1 (HO-1), a redoxsensitive inducible protein that provides protection against various forms of stress. A novel water soluble curcumin derivative (NCD) has been developed to overcome low in vivo bioavailability of curcumin. The aim of the present work is to evaluate the anti diabetic effects of the “NCD” and its effects on diabetes-induced ROS generation and lipid peroxidation in experimental type- 1 diabetes mellitus. We also examine whether the up regulation of HO-1 accompanied by increased HO activity mediates these antidiabetic and anti oxidant actions.Materials and methodsRats were divided into control group, control group receiving curcumin derivative, diabetic group, diabetic group receiving curcumin derivative and diabetic group receiving curcumin derivative and HO inhibitor ZnPP. Type-1 diabetes was induced by intraperitoneal injection of streptozotocin. Curcumin derivative was given orally for 45 days. At the planned sacrification time (after 45 days), fasting blood samples were withdrawn for estimation of plasma glucose, plasma insulin and lipid profile . Animals were sacrificed; pancreas, aorta and liver were excised for the heme oxygenase - 1 expression, activity and malondialdehyde estimation.ResultsNCD supplementation to diabetic rats significantly lowered the plasma glucose by 27.5% and increased plasma insulin by 66.67%. On the other hand, the mean plasma glucose level in the control group showed no significant difference compared to the control group receiving the oral NCD whereas, NCD supplementation to the control rats significantly increased the plasma insulin by 47.13% compared to the control. NCD decreased total cholesterol, triglycerides, LDL cholesterol and increased HDL cholesterol levels. Also, it decreased lipid peroxides (malondialdehyde) in the pancreas, aorta and liver.ConclusionThe (NCD) by its small dose possesses antidiabetic actions and that heme oxygenase induction seems to play an important role in its anti-diabetic effects. NCD also improves the lipid profile and oxidative status directly, proved by decreasing lipid peroxides (malondialdehyde) in pancreas, liver & aorta. The new water soluble curcumin derivative still retains the essential potencies of natural curcumin.


Journal of Systematics and Evolution | 2015

Plastid genome sequences of legumes reveal parallel inversions and multiple losses of rps16 in papilionoids

Erika N. Schwarz; Tracey A. Ruhlman; Jamal S. M. Sabir; Nahid H. Hajrah; Njud S. Alharbi; Abdulrahman L. Al-Malki; C. Donovan Bailey; Robert K. Jansen

To date, publicly available plastid genomes of legumes have for the most part been limited to the subfamily Papilionoideae. Here we report 13 new plastid genomes of legumes spanning all three subfamilies. The genomes representing Caesalpinioideae and Mimosoideae are highly conserved in gene content and gene order, similar to the ancestral angiosperm genome organization. Genomes within the Papilionoideae, however, have reduced sizes due to deletions in nine intergenic spacers primarily in the large single copy region. Our study also indicates that rps16 has been independently lost at least five times in legumes, with additional gene and intron losses scattered among the papilionoids. Additionally, genera from two distinct lineages within the papilionoids, Lupinus and Robinia, have a parallel inversion of 36 and 39 kb, respectively. This parallel inversion is novel as it appears to be caused by a 29 bp repeat within two trnS genes. This repeat is present in all available legume plastid genomes indicating that there is the potential for this inversion to be present in more species. This case of a homoplasious inversion is also evidence that some inversion events may not be reliable phylogenetic markers.


Scientific Reports | 2015

Mimosoid legume plastome evolution: IR expansion, tandem repeat expansions, and accelerated rate of evolution in clpP

Diana V. Dugas; David Hernandez; Erik J.M. Koenen; Erika N. Schwarz; Shannon C. K. Straub; Colin E. Hughes; Robert K. Jansen; Madhugiri Nageswara-Rao; Martijn Staats; J.T. Trujillo; Nahid H. Hajrah; Njud S. Alharbi; Abdulrahman L. Al-Malki; Jamal S. M. Sabir; C.D. Bailey

The Leguminosae has emerged as a model for studying angiosperm plastome evolution because of its striking diversity of structural rearrangements and sequence variation. However, most of what is known about legume plastomes comes from few genera representing a subset of lineages in subfamily Papilionoideae. We investigate plastome evolution in subfamily Mimosoideae based on two newly sequenced plastomes (Inga and Leucaena) and two recently published plastomes (Acacia and Prosopis), and discuss the results in the context of other legume and rosid plastid genomes. Mimosoid plastomes have a typical angiosperm gene content and general organization as well as a generally slow rate of protein coding gene evolution, but they are the largest known among legumes. The increased length results from tandem repeat expansions and an unusual 13 kb IR-SSC boundary shift in Acacia and Inga. Mimosoid plastomes harbor additional interesting features, including loss of clpP intron1 in Inga, accelerated rates of evolution in clpP for Acacia and Inga, and dN/dS ratios consistent with neutral and positive selection for several genes. These new plastomes and results provide important resources for legume comparative genomics, plant breeding, and plastid genetic engineering, while shedding further light on the complexity of plastome evolution in legumes and angiosperms.


International Journal of Biological Macromolecules | 2013

Horseradish peroxidase and chitosan: Activation, immobilization and comparative results

Saleh A. Mohamed; Abdulrahman L. Al-Malki; Taha Kumosani; Reda M. El-Shishtawy

Recently, horseradish peroxidase (HRP) was immobilized on activated wool and we envisioned that the use of chitosan would be interesting instead of wool owing to its simple chemical structure, abundant nature and biodegradability. In this work, HRP was immobilized on chitosan crosslinked with cyanuric chloride. FT-IR spectroscopy and scanning electron microscopy were used to characterize immobilized HRP. The number of ten reuses of immobilized HRP has been detected. The pH was shifted from 5.5 for soluble HRP to 5.0 for immobilized enzyme. The soluble HRP had an optimum temperature of 30 °C, which was shifted to 35 °C for immobilized enzyme. The soluble HRP and immobilized HRP were thermal stable up to 35 and 45 °C, respectively. The apparent kinetic constant values (K(m)) of soluble HRP and chitosan-HRP were 35 mM and 40 mM for guaiacol and 2.73 mM and 5.7 mM for H2O2, respectively. Immobilization of HRP partially protected them from metal ions compared to soluble enzyme. The chitosan-HRP was remarkably more stable against urea, Triton X-100 and organic solvents. Chitosan-HRP exhibited large number of reuses and more resistance to harmful compounds compared with wool-HRP. On the basis of results obtained in the present study, chitosan-HRP could be employed in bioremediation application.


Toxicology and Industrial Health | 2013

Protective effect of vitamin E and epicatechin against nicotine-induced oxidative stress in rats

Abdulrahman L. Al-Malki; Said S Moselhy

Nicotine is a major pharmacologically active and addictive component of tobacco smoke, which is regarded to be a primary risk factor in the development of cardiovascular and pulmonary diseases. Epicatechin is one of the most potent antioxidants present in the human diet. Particularly high levels of this compound are found in tea, apples and chocolate. It has been reported that tea extracts and/or its constituents have antibacterial, antiviral, antioxidative, antitumor and antimutagenic activities. Vitamin E is a major lipid-soluble antioxidant vitamin and free radical scavenger, presents as an integral component of cellular membranes and has important biological functions. The primary mechanism by which vitamin E is proposed to prevent cancer is through their antioxidant properties. The goal of this study is to evaluate the effect of epicatechin alone or combined with vitamin E in inhibiting the oxidative stress induced by nicotine in rats. Results obtained indicated that there was a significant elevation in the levels of malondialdhyde (MDA) in nicotine injected rats. The combined treatment (epicatechin + Vit E) group showed a potential reduction of these parameters more than individual treatment. The activities of superoxide dismutase, catalase and glutathione peroxidase were found significantly higher in combined treated than untreated rats. In nicotine group, a negative significant correlation between reduced glutathione and MDA (r = −0.92) was observed. In conclusion, these results suggested that the supplementation of diet with epicatechin and vitamin E provided antioxidant defense with strong chemopreventive activity against nicotine-induced carcinogenesis.


The Journal of Sexual Medicine | 2012

Effects of a Water‐Soluble Curcumin Protein Conjugate vs. Pure Curcumin in a Diabetic Model of Erectile Dysfunction

Tarek K. Motawi; Ameen M Rezq; Taymour Mostafa; Hanan Fouad; Hanan H. Ahmed; Laila A. Rashed; Dina Sabry; Amira M. Senbel; Abdulrahman L. Al-Malki; Raghda El‐Shafiey

INTRODUCTION Curcumin is involved in erectile signaling via elevation of cyclic guanosine monophosphate (cGMP). AIM Assessment of the effects of water-soluble curcumin in erectile dysfunction (ED). METHODS One hundred twenty male white albino rats were divided into: 1st and 2nd control groups with or without administration of Zinc protoporphyrin (ZnPP), 3rd and 4th diabetic groups with or without ZnPP, 5th diabetic group on single oral dose of pure curcumin, 6th diabetic group on pure curcumin administered daily for 12 weeks, 7th and 8th diabetic groups on single dose of water-soluble curcumin administered with or without ZnPP, 9th and 10th diabetic groups on water-soluble curcumin administered daily for 12 weeks with or without ZnPP. All curcumin dosage schedules were administered after induction of diabetes. MAIN OUTCOME MEASURES Quantitative gene expression of endothelial nitric oxide synthase (eNOS), neuronal NOS (nNOS), inducible NOS (iNOS), heme oxygenase-1 (HO-1), nuclear transcription factor-erythroid2 (Nrf2), NF-Кβ, and p38. Cavernous tissue levels of HO and NOS enzyme activities, cGMP and intracavernosal pressure (ICP). RESULTS Twelve weeks after induction of diabetes, ED was confirmed by the significant decrease in ICP. There was a significant decrease in cGMP, NOS, HO enzymes, a significant decrease in eNOS, nNOS, HO-1 genes and a significant elevation of NF-Кβ, p38, iNOS genes. Administration of pure curcumin or its water-soluble conjugate led to a significant elevation in ICP, cGMP levels, a significant increase in HO-1 and NOS enzymes, a significant increase in eNOS, nNOS, HO-1, and Nrf2 genes, and a significant decrease in NF-Кβ, p38, and iNOS genes. Water-soluble curcumin showed significant superiority and more prolonged duration of action. Repeated doses regimens were superior to single dose regimen. Administration of ZnPP significantly reduced HO enzyme, cGMP, ICP/ mean arterial pressure (MAP), HO-1 genes in diabetic groups. CONCLUSION Water-soluble curcumin could enhance erectile function with more effectiveness and with more prolonged duration of action.


Human & Experimental Toxicology | 2011

The protective effect of epicatchin against oxidative stress and nephrotoxicity in rats induced by cyclosporine

Abdulrahman L. Al-Malki; Said S Moselhy

Cyclosporine A (CyA) is the first-line immunosuppressant used for the management of solid organ transplantation and autoimmune diseases. Reactive oxygen species (ROS) can attack all types of macromolecules including DNA and damage it. Epicatechin (EC) is one of the most potent antioxidants present in the human diet. Particularly high levels of this compound are found in tea, apples, and chocolate. The goal of this study was to evaluate the protective effect of EC against CyA toxicity and its antioxidant activity in transplanted patients to avoid its side effects. Results obtained showed that, CyA exert its toxic effect by increasing the free radicals and ROS that causes lipid peroxidation and cell damage, this is detected by elevation of hydroperoxides and thiobarbituric acid reactive substances, while the activities of antioxidant enzymes include (superoxide dismutase [SOD], catalase [CAT] and glutathione peroxidase [GPx]) were significantly decreased as compared with control rats. The deleterious toxic effects of CyA are, at least in part, due to increased production of free radicals and ROS. Treatment of rats with epicatchin ameliorates the toxicity of CyA by decreasing the lipid peroxidation and enhanced the antioxidants enzyme activities.


Journal of Microbiology | 2013

Solid state production of polygalacturonase and xylanase by Trichoderma species using cantaloupe and watermelon rinds

Saleh A. Mohamed; Abdulrahman L. Al-Malki; Jalaluddin A. Khan; Saleh A. Kabli; Saleh M. Al-Garni

Different solid state fermentation (SSF) sources were tested such as cantaloupe and watermelon rinds, orange and banana peels, for the production of polygalacturonase (PG) and xylanase (Xyl) by Trichoderma harzianum and Trichoderma virens. The maximum production of both PG and Xyl were obtained by T. harzianum and T. virnes grown on cantaloupe and watermelon rinds, respectively. Time course, moisture content, temperature, pH, supplementation with carbon and nitrogen sources were optimized to achieve the maximum production of both PG and Xyl of T. harzianum and T. virens using cantaloupe and watermelon rinds, respectively. The maximum production of PG and Xyl of T. harzianum and T. virens was recorded at 4–5 days of incubation, 50–66% moisture, temperature 28–35°C and pH 6–7. The influence of supplementary carbon and nitrogen sources was studied. For T. harzianum, lactose enhanced PG activity from 87 to 120 units/g solid, where starch and maltose enhanced Xyl activity from 40 to 55–60 units/g solid for T. virnes. Among the nitrogen sources, ammonium sulphate, ammonium nitrate, yeast extract and urea increased PG activity from 90 to 110–113 units/g solid for T. harzianum. Similarly, ammonium chloride, ammonium sulphate and yeast extract increased Xyl activity from 45 to 55–70 units/g solid for T. virens.


Comparative and Functional Genomics | 2015

Proteome Analysis for Understanding Abiotic Stress (Salinity and Drought) Tolerance in Date Palm (Phoenix dactylifera L.)

Haddad A. El Rabey; Abdulrahman L. Al-Malki; Khalid O. Abulnaja; Wolfgang Rohde

This study was carried out to study the proteome of date palm under salinity and drought stress conditions to possibly identify proteins involved in stress tolerance. For this purpose, three-month-old seedlings of date palm cultivar “Sagie” were subjected to drought (27.5 g/L polyethylene glycol 6000) and salinity stress conditions (16 g/L NaCl) for one month. DIGE analysis of protein extracts identified 47 differentially expressed proteins in leaves of salt- and drought-treated palm seedlings. Mass spectrometric analysis identified 12 proteins; three out of them were significantly changed under both salt and drought stress, while the other nine were significantly changed only in salt-stressed plants. The levels of ATP synthase alpha and beta subunits, an unknown protein and some of RubisCO fragments were significantly changed under both salt and drought stress conditions. Changes in abundance of superoxide dismutase, chlorophyll A-B binding protein, light-harvesting complex1 protein Lhca1, RubisCO activase, phosphoglycerate kinase, chloroplast light-harvesting chlorophyll a/b-binding protein, phosphoribulokinase, transketolase, RubisCO, and some of RubisCO fragments were significant only for salt stress.

Collaboration


Dive into the Abdulrahman L. Al-Malki's collaboration.

Top Co-Authors

Avatar

Taha Kumosani

King Abdulaziz University

View shared research outputs
Top Co-Authors

Avatar

Said S Moselhy

King Abdulaziz University

View shared research outputs
Top Co-Authors

Avatar

Hani Choudhry

King Abdulaziz University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Nahid H. Hajrah

King Abdulaziz University

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge