Manal Abd El Mohsen

University of Reading, Reading, ENG, United Kingdom

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Publications (8)30.5 Total impact

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    ABSTRACT: Phytochemical-rich foods have been shown to be effective at reversing age-related deficits in memory in both animals and humans. We show that a supplementation with a blueberry diet (2% w/w) for 12 weeks improves the performance of aged animals in spatial working memory tasks. This improvement emerged within 3 weeks and persisted for the remainder of the testing period. Memory performance correlated well with the activation of cAMP-response element-binding protein (CREB) and increases in both pro- and mature levels of brain-derived neurotrophic factor (BDNF) in the hippocampus. Changes in CREB and BDNF in aged and blueberry-supplemented animals were accompanied by increases in the phosphorylation state of extracellular signal-related kinase (ERK1/2), rather than that of calcium calmodulin kinase (CaMKII and CaMKIV) or protein kinase A. Furthermore, age and blueberry supplementation were linked to changes in the activation state of Akt, mTOR, and the levels of Arc/Arg3.1 in the hippocampus, suggesting that pathways involved in de novo protein synthesis may be involved. Although causal relationships cannot be made among supplementation, behavior, and biochemical parameters, the measurement of anthocyanins and flavanols in the brain following blueberry supplementation may indicate that changes in spatial working memory in aged animals are linked to the effects of flavonoids on the ERK-CREB-BDNF pathway.
    Free Radical Biology and Medicine 09/2008; 45(3):295-305. · 5.27 Impact Factor
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    ABSTRACT: In order to establish firm evidence for the health effects of dietary polyphenol consumption, it is essential to have quantitative information regarding their dietary intake. The usefulness of the current methods, which rely mainly on the assessment of polyphenol intake using food records and food composition tables, is limited as they fail to assess total intake accurately. This review highlights the problems associated with such methods with regard to polyphenol-intake predictions. We suggest that the development of biological biomarkers, measured in both blood and urine, are essential for making accurate estimates of polyphenol intake. However, the relationship between dietary intakes and nutritional biomarkers are often highly complex. This review identifies the criteria that must be considered in the development of such biomarkers. In addition, we provide an assessment of the limited number of potential biomarkers of polyphenol intake currently available.
    British Journal Of Nutrition 02/2008; 99(1):12-22. · 3.30 Impact Factor
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    ABSTRACT: Recent reports have demonstrated various cardiovascular and neurological benefits associated with the consumption of foods rich in anthocyanidins. However, information regarding absorption, metabolism, and especially, tissue distribution are only beginning to accumulate. In the present study, we investigated the occurrence and the kinetics of various circulating pelargonidin metabolites, and we aimed at providing initial information with regard to tissue distribution. Based on HPLC and LC-MS analyses we demonstrate that pelargonidin is absorbed and present in plasma following oral gavage to rats. In addition, the main structurally related pelargonidin metabolite identified in plasma and urine was pelargonidin glucuronide. Furthermore, p-hydroxybenzoic acid, a ring fission product of pelargonidin, was detected in plasma and urine samples obtained at 2 and 18 h after ingestion. At 2 h post-gavage, pelargonidin glucuronide was the major metabolite detected in kidney and liver, with levels reaching 0.5 and 0.15 nmol pelargonidin equivalents/g tissue, respectively. Brain and lung tissues contained detectable levels of the aglycone, with the glucuronide also present in the lungs. Other tissues, including spleen and heart, did not contain detectable levels of pelargonidin or ensuing metabolites. At 18 h post-gavage, tissue analyses did not reveal detectable levels of the aglycone nor of pelargonidin glucuronides. Taken together, our results demonstrate that the overall uptake of the administered pelargonidin was 18 % after 2 h, with the majority of the detected levels located in the stomach. However, the amounts recovered dropped to 1.2 % only 18 h post-gavage, with the urine and faecal content constituting almost 90 % of the total recovered pelargonidin.
    British Journal Of Nutrition 02/2006; 95(1):51-8. · 3.30 Impact Factor
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    ABSTRACT: Recent reports have demonstrated various cardiovascular and neurological benefits associated with the consumption of foods rich in anthocyanidins. However, information regarding absorption, metabolism, and especially, tissue distribution are only beginning to accumulate. In the present study, we investigated the occurrence and the kinetics of various circulating pelargonidin metabolites, and we aimed at providing initial information with regard to tissue distribution. Based on HPLC and LC-MS analyses we demonstrate that pelargonidin is absorbed and present in plasma following oral gavage to rats. In addition, the main structurally related pelargonidin metabolite identified in plasma and urine was pelargonidin glucuronide. Furthermore, p-hydroxybenzoic acid, a ring fission product of pelargonidin, was detected in plasma and urine samples obtained at 2 and 18h after ingestion. At 2h post-gavage, pelargonidin glucuronide was the major metabolite detected in kidney and liver, with levels reaching 0·5 and 0·15nmol pelargonidin equivalents/g tissue, respectively. Brain and lung tissues contained detectable levels of the aglycone, with the glucuronide also present in the lungs. Other tissues, including spleen and heart, did not contain detectable levels of pelargonidin or ensuing metabolites. At 18h post-gavage, tissue analyses did not reveal detectable levels of the aglycone nor of pelargonidin glucuronides. Taken together, our results demonstrate that the overall uptake of the administered pelargonidin was 18% after 2h, with the majority of the detected levels located in the stomach. However, the amounts recovered dropped to 1·2% only 18h post-gavage, with the urine and faecal content constituting almost 90% of the total recovered pelargonidin.
    The British journal of nutrition 12/2005; 95(01):51 - 58. · 3.45 Impact Factor
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    ABSTRACT: The free radical theory of ageing postulates that age-associated neurodegeneration is caused by an imbalance between pro-oxidants and antioxidants resulting in oxidative stress. The current study showed regional variation in brain susceptibility to age-associated oxidative stress as shown by increased lipofuscin deposition and protein carbonyl levels in male rats of age 15-16 months compared to control ones (3-5 months). The hippocampus is the area most vulnerable to change compared to the cortex and cerebellum. However, proteasomal enzyme activity was not affected by age in any of the brain regions studied. Treatment with melatonin or coenzyme Q10 for 4 weeks reduced the lipofuscin content of the hippocampus and carbonyl level. However, both melatonin and coenzyme Q10 treatments inhibited beta-glutamyl peptide hydrolase activity. This suggests that these molecules can alter proteasome function independently of their antioxidant actions.
    Biochemical and Biophysical Research Communications 11/2005; 336(2):386-91. · 2.28 Impact Factor
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    ABSTRACT: Citrus flavonoids have been investigated for their biological activity, with both anti-inflammatory and -carcinogenic effects being reported. However, little information is known on the bioavailability of these compounds in vivo. The objectives of this study were to determine the tissue distribution of naringenin after gastric gavage of [3H]-naringenin to rats. Unlabelled naringenin was also used to quantify the levels of naringenin and its major metabolites in tissues and eliminated in the urine and faeces. Significant radioactivity was detected in the plasma as well as all tissues examined 2h post-gavage. After 18h, higher levels of radioactivity were retained in plasma and tissues (55% of the administered radioactivity). Investigation of the nature of metabolites, using unlabelled naringenin, revealed that the glucuronides were the major components in plasma, tissues and urine, in addition to the colonic metabolite 3-(4-hydroxyphenyl) propionic acid, detected in the urine. The aglycone was the form extensively retained in tissues after 18h post-gavage. Total identified metabolites detected after 18h in most tissues were only 1-5% of the levels detected after 2h. However, the brain, lungs and heart retained 27, 20 and 11%, respectively, relative to the total metabolites detected at 2h. While radioactive detection suggests increased levels of breakdown products of naringenin after 18 h versus 2 h, the products identified using unlabelled naringenin are not consistent with this, suggesting that a predominant proportion of the naringenin breakdown products at 18 h are retained as smaller decomposition molecules which cannot yet be identified.
    Free Radical Research 01/2005; 38(12):1329-40. · 3.28 Impact Factor
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    ABSTRACT: Epicatechin is a flavan-3-ol that is commonly present in green teas, red wine, cocoa products, and many fruits, such as apples. There is considerable interest in the bioavailability of epicatechin after oral ingestion. In vivo studies have shown that low levels of epicatechin are absorbed and found in the circulation as glucuronides, methylated and sulfated forms. Recent research has demonstrated protective effects of epicatechin and one of its in vivo metabolites, 3'-O-methyl epicatechin, against neuronal cell death induced by oxidative stress. Thus, we are interested in the ability of ingested epicatechin to cross the blood brain barrier and target the brain. Rats were administered 100 mg/kg body weight/d epicatechin orally for 1, 5, and 10 d. Plasma and brain extracts were analyzed by HPLC with photodiode array detection and LC-MS/MS. This study reports the presence of the epicatechin glucuronide and 3'-O-methyl epicatechin glucuronide formed after oral ingestion in the rat brain tissue.
    Free Radical Biology and Medicine 01/2003; 33(12):1693-702. · 5.27 Impact Factor
  • M M Abd el Mohsen, A T Fahim, T M Motawi, N A Ismail
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    ABSTRACT: This work aimed to study the changes in sex hormones and lipid profile in adult female albino rats subjected to treatment with nicotine (N), immobilization stress (S), or their combinations (N+S). These treatments were applied either for one day (T1) or daily for 10 days (T10), after which rats in the estrus stage were used for the determination of plasma corticosterone (CS), serum sex hormones as progesterone (P), estrogen (E), FSH, LH and serum lipid profile including total cholesterol (TC), HDL-C, LDL-C, triacylglycerol (TG) and non esterified fatty acids (NEFA). It was clear that either N or S raised plasma CS and serum P levels in both the treatment regimens and that N+S induced a higher level of these hormones compared to each treatment alone. Serum E level was only elevated during T10 regimen only. An increase in serum LH level was only observed after a single exposure to either N or S, however their combination abolished the stimulatory effect induced by each treatment alone. Serum FSH was not altered by exposure to either N or S alone in both regimens, but in the T10 regimen their combination significantly lowered FSH level. Regarding the effect on serum lipid profile, serum TC was increased in all T10 regimen groups. LDL-C was increased by N+S treatment in both regimens, however no change in HDL-C level was observed in all groups. Serum NEFA was increased in all the treated groups during T10 regimen, while in the T1 regimen NEFA level was only elevated by the combination N+S. Serum TG was insignificantly altered in all the treated groups. The observed changes in the lipid pattern were attributed to the alterations occurred in CS and female sex hormones that caused by N, S or their combinations.
    Pharmacological Research 04/1997; 35(3):181-7. · 4.35 Impact Factor

Publication Stats

443 Citations
30.50 Total Impact Points

Institutions

  • 2005–2008
    • University of Reading
      • School of Psychology and Clinical Language Sciences
      Reading, ENG, United Kingdom
  • 2003–2006
    • King College
      Gatlinburg, Tennessee, United States
  • 1997
    • Cairo University
      • Department of Biochemistry
      Cairo, Muhafazat al Qahirah, Egypt