Browsing by Person "Al-Dujaili, Emad A. S."

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A short study exploring the effect of the glycaemic index of the diet on energy intake and salivary steroid hormones
(2019-01-24) Al-Dujaili, Emad A. S.; Ashmore, Sophie; Tsang, Catherine
The glycaemic index or load (GI or GL) is a concept for ranking carbohydrate-rich foods based on the postprandial blood glucose response compared with a reference food (glucose). Due to the limited research investigating the effect of the GI or GL of the diet on salivary steroidal hormones, this explorative short study was conducted. 12 female participants consumed a low GI and a high GI diet for three days each, followed by a washout period between each intervention. Saliva was collected at baseline, and following the low or high GI diets. Cortisol and testosterone concentrations were measured by enzyme-linked immuno-sorbent assay (ELISA). GI and GL were significantly different between the low and high GI diets ( < 0.001). There was a small but significant increase in salivary cortisol after the high GI diet (7.38 to 10.93 ng/mL, = 0.036). No effect was observed after the low GI diet. Higher levels of testosterone were produced after the low GI diet (83.7 to 125.9 pg/mL, = 0.002), and no effect was found after the high GI diet. The total intake of calories consumed on the low GI diet was significantly lower compared to the high GI diet ( = 0.019). A low GI diet was associated with a small but significant increase in salivary testosterone, while a high GI diet increased cortisol levels. Altering the GI of the diet may influence overall energy intake and the health and wellbeing of female volunteers.
Antioxidant Properties and Beneficial Cardiovascular Effects of a Natural Extract of Pomegranate in Healthy Volunteers: A Randomized Preliminary Single-Blind Controlled Study
(MDPI, 2022-10-28) Al-Dujaili, Emad A. S.; Casey, Ciara; Stockton, Angela
Pomegranates are known to possess anti-hypertensive, anti-atherogenic and cardioprotective effects mainly due to their pleiotropic effects on various cellular pathways, especially those triggered by oxidative stress. The aim of this study was to investigate the effect of natural standardized pomegranate (PE) extract on cardiovascular risk factors in 24 healthy volunteers who participated in a randomized, single-blind placebo-controlled study. There were 12 subjects in the PE group and 12 in the placebo group. Variables were measured at baseline and after 14 and 28 days of supplementation are anthropometry, BP, pulse wave velocity, fat and lean body mass, salivary and urinary cortisol, and cortisone, total phenolics, antioxidant capacity and lipid peroxidation. Urinary total phenolics excretion and antioxidant capacity were significantly increased after 14 and 28 days of PE intake. At day 28, there were also statistically significant decreases in systolic and diastolic blood pressure (BP), pulse wave velocity, body fat and fat mass, as well as an increase in lean body mass. Significant changes in the placebo group were not found. Glucocorticoid levels showed a significant decrease in saliva cortisol at day 28 (morning) in the PE group, and cortisol/cortisone ratio was significantly decreased following 28 days of PE intake at morning, noon, and evening. Urine free cortisol was significantly reduced at day 14. These findings suggest that pomegranate extract intake may improve antioxidant and oxidative stress status and play a beneficial role in the attenuation of some cardiovascular risk factors. Future studies should concentrate on overweight and older people.
Bioavailability and Urinary Excretion of Phenolic-Derived Metabolites after Acute Consumption of Purple Majesty Potato in Humans
(E-Cronicon, 2015-03-18) Tsang, Catherine; Smail, Nacer F.; McDougall, Gordon J.; Almoosawi, Suzana; Al-Dujaili, Emad A. S.
A novel purple potato variety, Purple Majesty (PM) contains an abundance of phenolic compounds, especially anthocyanins. The aim of this study was to assess the bioavailability of phenolic compounds in plasma measured as total polyphenols and urinary excretion of phenolic-derived metabolites after acute consumption of cooked PM. Five healthy male subjects (27-60 years; mean BMI: 26.7 ± 4.1) participated in a bioavailability study. Blood and urine were sampled at baseline and following consumption of 400 g cooked PM at 1h, 2h, 4h and 24h. A peak plasma antioxidant capacity was reached 1-2 hours post-consumption (from 1044 ± 281 µmol/L Fe(II) at baseline and increased to 1257 ± 180 after 1 hour (p = 0.045) and 1112 ± 251 µmol/L Fe(II) after 2 hours (borderline significance of p = 0.06). Total phenols level in plasma was reached after 2 hours (from 342.4 ± 28.3 at baseline to 368.4 ± 25 mg/L GAE). Liquid chromatography mass spectrometric (LC-MS) analysis was used to track the levels of anthocyanin-like derivatives and metabolites in the urine of volunteers after intake of the cooked Purple Majesty potatoes. No anthocyanin derivatives were detected in urine by liquid chromatography mass spectrometry indicating levels were < 2 nM. The majority of peaks that increased after intake were putatively identified as sulphated phenolic metabolites. Phenolic glucuronides were identified but other peaks remain unidentified. Hippuric acid was identified as a major phenolic derivative. Hydroxy benzoic derivatives, characteristic of intake of anthocyanins, were not detected in urine, however metabolites expected from the B-ring of petunidin (i.e. methyl gallic acid) may have been obscured by other peaks. Some metabolites could have arisen through metabolism of chlorogenic acid, which is present at ~ equivalent amounts to anthocyanins in cooked PM. In conclusion, acute consumption of PM resulted in an increase in excretion of urinary phenolic-derived metabolites. Identifying these unknown phenolic derivatives warrants further investigation.
Comparison of the Effects of High versus Low-Polyphenol Dark Chocolate on Body Weight and Biochemical Markers: A Randomized Trial
(E-Cronicon, 2015-09-12) Farhat, Grace; Drummond, Sandra; Fyfe, Lorna; McDougall, G.; Al-Dujaili, Emad A. S.
Background: Dark chocolate (DC) has amongst the highest content of polyphenols in foods, but the chocolate processing methods may greatly reduce this amount. Few studies addressed the possible detrimental effects of low polyphenol DC on body weight, glucose metabolism and lipid levels, and the potential role of cocoa flavanols in body weight control. Therefore, this study aimed to determine the effect of DC rich and DC low in polyphenols on BMI, fasting blood glucose, high sensitivity C-reactive protein (hs-CRP) and lipid levels in adults. Methods: Sixty-one participants took part in a randomized parallel trial. Volunteers randomly received 20g daily of either PRDC (polyphenol-rich DC) or of low polyphenol DC (LPDC) for four weeks. Anthropometric measures and blood samples were collected at baseline and after 4 weeks. Results: A significant net increase in BMI (0.17 0.32 kg/m2, p = 0.007), fasting blood glucose (0.44 1.08 mmol/l, p = 0.041) and triglycerides levels (0.13 0.23 mmol/l, p = 0.008) was observed in the low polyphenol DC group following the 4 weeks intervention, while the levels of these parameters did not significantly change in the polyphenol-rich DC group. There was no significant change in hs-CRP levels in both groups. Conclusions: Results show that the intake of PRDC seems to be more metabolically healthy than LPDC intake, and this highlights the potential role of polyphenols in counteracting the negative effects of fat and energy intake in chocolate. The outcomes raise concerns about the polyphenol content and quality of DC products in the market. Further studies are needed to fully investigate the health benefits of dark chocolate intake, compare the effects of different types of chocolate and establish the necessary guidelines of the type and content of polyphenols in the chocolate preparations to ensure their favourable effect on health.
Conditional deletion of Hsd11b2 in the brain causes salt appetite and hypertension
(American Heart Association, 2016-03-07) Evans, Louise C.; Ivy, Jessica R.; Wyrwoll, Caitlin; McNairn, Julie A.; Menzies, Robert I.; Christensen, Thorbjørn H.; Al-Dujaili, Emad A. S.; Kenyon, Christopher J.; Mullins, John J.; Seckl, Jonathan R.; Holmes, Megan C.; Bailey, Matthew A.
Background—The hypertensive syndrome of Apparent Mineralocorticoid Excess is caused by loss-of-function mutations in the gene encoding 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), allowing inappropriate activation of the mineralocorticoid receptor by endogenous glucocorticoid. Hypertension is attributed to sodium retention in the distal nephron, but 11βHSD2 is also expressed in the brain. However, the central contribution to Apparent Mineralocorticoid Excess and other hypertensive states is often overlooked and is unresolved. We therefore used a Cre-Lox strategy to generate 11βHSD2 brain-specific knockout (Hsd11b2.BKO) mice, measuring blood pressure and salt appetite in adults.
Consumption of Green Coffee Reduces Blood Pressure and Body Composition by Influencing 11_-HSD1 Enzyme Activity in Healthy Individuals: A Pilot Crossover Study Using Green and Black Coffee
(2014-07) Revuelta-Iniesta, Raquel; Al-Dujaili, Emad A. S.
Dietary polyphenols may have a protective role against the development of CVD. Thus, we aimed to investigate the effects of green coffee (GC), rich in chlorogenic acid, and black coffee (BC) on cardiovascular markers. A randomised pilot crossover study was performed on healthy subjects who consumed both coffees for 2 weeks. We measured anthropometry, blood pressure, and arterial elasticity after each intervention and collected urine samples to monitor antioxidant capacity. Free cortisol and cortisone levels were obtained from urine and analysed by specific ELISA methods. Systolic blood pressure (P = 0.018) and arterial elasticity (P = 0.001) were significantly reduced after GC. BMI (P = 0.04 for BC; P = 0.01 for GC) and abdominal fat (P = 0.01 for BC; P = 0.009 for GC) were also significantly reduced with no changes in energy intake. Urinary free cortisol was significantly reduced from 125.6 85.9 nmol/day to 76.0 54.9 nmol/day following GC and increased to 132.1 89.1 nmol/day after BC. Urinary free cortisone increased by 18% following BC and 9% following GC (nonsignificant). Cortisol/cortisone ratio (indicating 11_-HSD1 activity) was reduced after GC (from 3.5 1.9 to 1.7 1.04, P = 0.002). This suggests that GC can play a role in reducing cardiovascular risk factors. Further research including hypertensive and overweight individuals will now be justified to clarify whether GC could have a therapeutic role in CVD. 2014 R. Revuelta-Iniesta and E. A. S. Al-Dujaili.
Consumption of Pomegranate Juice Attenuates Exercise - Induced Oxidative Stress, Blood Pressure and Urinary Cortisol/Cortisone Ratio in Human Adults
(E-Cronicon, 2016-08-23) Al-Dujaili, Emad A. S.; Good, Gillian; Tsang, Catherine
Background: Oxidative stress is exacerbated in overweight and obese individuals after acute exercise compared with their nonobese counterparts. Antioxidants supplementation of the diet may be one intervention to reduce exercise-induced oxidative stress in this vulnerable population. The aim of this study was to investigate whether polyphenol-rich pomegranate juice attenuates postexercise oxidative stress and contributors to oxidative stress (glucocorticoids) and blood pressure in healthy overweight subjects. Methods: Males and females participated in a randomized placebo controlled parallel pilot-study (mean BMI: 26.7 ± 6.6 kg/m2 ). Two groups of (n = 12) participants received either pomegranate pure juice (500 mL/day containing total polyphenols of 1685 mg GAE/L) or placebo (water matched for total energy) and all participants completed two standardized 30 min treadmill tests (50% Wmax) at baseline and after one week of the intervention. Results: Exercise induced lipid peroxidation (MDA) was lower following pomegranate juice consumption compared with placebo (31.2 ± 10.6 to 26.5 ± 9.8 MDA µmole/day) after 1 week (P = 0.035). Urinary free cortisol was reduced from 179.4 ± 53.2 to 125.6 ± 43.5 nmole/24h which was significant (p = 0.042). In addition, there was a statistically significant increase in urinary free cortisone: from 112.2 ± 40.4 to 187.6 ± 90.2 nmole/24 h (p = 0.045), and a significant decrease in the urinary free cortisol/cortisone ratio (p=0.009) from 1.6 ± 1.1 to 0.67 ± 0.55 following one week of pomegranate juice intake. Pomegranate juice consumption was also found to decrease systolic blood pressure pre-exercise (136.7 ± 11.7 to 131.8 ± 8.8 mmHg (p = 0.007), and post-exercise from 158.8 ± 15.8 to 148.1 ± 12.3 mmHg (p < 0.01) and diastolic blood pressure (86.3 ± 10.6 to 82.5 ± 6.8 mmHg (p = 0.04) and 103.1 ±12.5 to 93.9 ± 11.5 mmHg (p = 0.001), pre and post exercise, respectively. Correlation results between the change in Cortisol/cortisone ratio with the effect on blood pressure showed a negative significant association post pomegranate juice intake (p = 0.028 for systolic and p = 0,008 for diastolic BP). There were no changes in lipid peroxidation or blood pressure following placebo treatment. Conclusions: These findings suggest that pomegranate juice consumption prior to an acute bout of moderate intensity exercise can alleviate blood pressure and exercise-induced stress in the overweight and obese population.
Cues to sex- and stress-hormones in the human male face: Functions of glucocorticoids in the immunocompetence handicap hypothesis
(Elsevier, 2011-08) Moore, F. R.; Al-Dujaili, Emad A. S.; Cornwell, R. E.; Smith, M. J. L.; Lawson, J. F.; Sharp, M.; Perrett, D. I.
The stress-linked version of the immunocompetence handicap hypothesis has been proposed to account for inconsistencies in relationships between testosterone and immune response. The model has received some support from studies demonstrating roles of stress hormones in relationships between testosterone, immune function and secondary sexual ornamentation. Such work, however, has relied on artificial elevation of testosterone so may not reflect relationships in natural populations. We created human male facial stimuli on the basis of naturally co-occurring levels of salivary testosterone and the stress hormone cortisol. In Study 1 we tested female preferences for male faces with cues to combinations of the hormones across the menstrual cycle, and in Study 2 we tested perceptions of health and dominance in a novel set of facial stimuli. Females preferred cues to low cortisol, a preference that was strongest during the fertile phase of the menstrual cycle. The effects of cortisol on attractiveness and perceived health and dominance were contingent upon level of testosterone: the effects of the stress hormone were reduced when testosterone was high. We propose explanations for our results, including low cortisol as a cue to a heritable component of health, attractiveness as a predictor of low social-evaluative threat (and, therefore, low baseline cortisol) and testosterone as a proxy of male ability to cope efficiently with stressors.
Dark Chocolate: An Obesity Paradox or a Culprit for Weight Gain?
(John Wiley & Sons, Ltd, 2014-06-02) Farhat, Grace; Drummond, Sandra; Fyfe, Lorna; Al-Dujaili, Emad A. S.
Obesity remains a major public health challenge, and its prevalence is dramatically increasing. Diet and exercise are typically recommended to prevent and manage obesity; however, the results are often conflicting. Polyphenols, a class of phytochemicals that have been shown to reduce the risk factors for diabetes type II and cardiovascular diseases, are recently suggested as complementary agents in the management of obesity through several mechanisms such as decreasing fat absorption and/or fat synthesis. Dark chocolate, a high source of polyphenols, and flavanols in particular, has lately received attention for its possible role in modulating obesity because of its potential effect on fat and carbohydrate metabolism, as well as on satiety. This outcome was investigated in animal models of obesity, cell cultures and few human observational and clinical studies. The research undertaken to date has shown promising results, with the possible implication of cocoa/dark chocolate in the modulation of obesity and body weight through several mechanisms including decreasing the expression of genes involved in fatty acid synthesis, reducing the digestion and absorption of fats and carbohydrates and increasing satiety. 2013 John Wiley & Sons, Ltd.
Detection of endogenous nandrolone in the urine of healthy volunteers by utilising a sensitive ELISA
(2005) Al-Dujaili, Emad A. S.; Mason, J. I.; Swart, P.
Recent studies report that nandrolone, a widely used anabolic steroid by athletes to enhance their performance, is produced endogenously in the humans. However, the detection of nandrolone has mainly been indicated by the measurement of its urinary metabolites (19-norandrosterone and 19-noretiocholanone). The aim of this study was to develop a sensitive and specific ELISA for nandrolone to investigate whether the parent steroid can be detected in the urine of healthy volunteers. Nandrolone antibodies were produced by immunising sheep with nandrolone-3-CMO-KLH immunogen and used with HRP-donkey anti-sheep IgG conjugate as tracer to develop the ELISA method. Cross-reactivity values of anti-nandrolone antibody with major interfering steroids including nandrolone metabolites were minimal except for testosterone (1.8%) and dihydrotestosterone (3.98%). A sensitive standard curve for nandrolone ELISA has been constructed with good reproducibility and a minimum detection limit of 12.75 pmole/L (3.5 pg/mL). The assay was evaluated for specificity, sensitivity, parallelism, accuracy and imprecision and all found to be satisfactory. The validity of the urinary nandrolone assay was confirmed by the excellent correlation between the ELISA results and those obtained by LC/MS/MS (ELISANand=1.06 LC/MS/MS Nand+0.032, R2=0.98, p<0.001). Urinary nandrolone excretion in healthy volunteers who were known not to have taken any anabolic steroids was assessed in exercising and non-exercising individuals. In non-exercising females, endogenous urinary nandrolone levels were found to range from 0.014-2.122 ng/mL (0.069-8.98 nmol/ day), and 0.017-1.291 nmol/day for exercising females. In non-exercising males, the levels ranged from 0.018-0.486 ng/mL (0.078-2.341 nmol/day), and 0.041-2.44 nmol/day for exercising males. In conclusion, a simple, rapid and sensitive ELISA method has been developed to estimate urinary excretion of nandrolone, and used for the detection of this steroid in urine. It seems likely that nandrolone as such, though at parts per billion, is excreted in the urine of healthy subjects not knowingly ingesting steroids.
Development and validation of a highly sensitive and specific enzyme immunosorbant assay for aldosterone: application to urine samples from cyp11b1 knockout mice
(2008-04) Al-Dujaili, Emad A. S.; Kenyon, C. J.; Mullins, L. J.; Mullins, J. J.
The majority of immunoassays used to measure aldosterone (most potent mineralocorticoid) levels are still based on radio-iodinated tracer, lack sensitivity and specificity and there is a definite need for their improvement. The aim of this project is to develop a highly sensitive and specific ELISA method for urinary aldosterone estimation in samples obtained from wild type and cyp11b1 knockout mice. Antibodies against aldosterone were raised in sheep as previously described. HRP-Donkey-anti-sheep IgG enzyme tracer was produced in our laboratory using the Lightning-Link HRP technique (Innova Biosciences, Cambridge) and used to develop the ELISA method. Urine samples obtained from wild type and null mice were first hydrolysed with Helix Pomatia (Sigma), extracted with dichloromethane and reconstituted in assay buffer. Aliquots were then assayed using the ELISA technique previously published following some modifications to sensitise the assay (Al-Dujaili 2006, Clinica Chimica Acta 364 172-179). The aldosterone ELISA was validated for specificity, sensitivity, parallelism, accuracy and imprecision. Cross-reactivity with major interfering steroids was minimal: corticosterone=0.018%, cortisol=0.0014%, DOC=0.013% except for 5-dihydro-aldosterone=1.65%. Minimum detection limit of this ELISA was 2.2 pg/ml (6.2 pmol/l). The validity of urinary aldosterone ELISA was confirmed by the excellent correlation between the results obtained before and after solvent extraction and HPLC separation step (Y=1.048X+0.006, R2=0.998, n=42). Accuracy studies, parallelism and imprecision data were determined and all found to be satisfactory. Using this assay, mean urinary aldosterone levels in male wild type and null mice on normal sodium diet were 42.710.3 (S.E.M.) pmol/g per day and 16.12.7 pmol/g per day, and on low sodium diet were 132.524.2 and 37.610.3 pmol/g per day, respectively. In conclusion, a simple and highly sensitive ELISA has been developed to estimate urinary excretion of aldosterone and the assay can clearly confirm the animal's sodium intake status and distinguish between urinary aldosterone levels in wild type and null mice.
Development and validation of highly sensitive and specific enzyme immunosorbant assays for deoxycorticosterone and corticosterone: application to urine samples from cyp11b1 knockout mice
(2008-04) Al-Dujaili, Emad A. S.; Kenyon, C. J.; Mullins, L. J.; Mullins, J. J.
Deoxycorticosterone (DOC: a weak mineralocorticoid) is the precursor to corticosterone (B: the major glucocorticoid in rodents) and aldosterone. Cyp11b1 encodes 11_-hydroxylase which catalyses the conversion of DOC to B in rodents. The aim of this study is to develop sensitive and specific ELISA methods to estimate urinary DOC and B levels in mice. Antibodies against DOC and B were raised in rabbits by our laboratories as previously described and HRP-Goat anti-Rabbit IgG enzyme tracer (Upstate, UK) were used to develop the ELISA methods. Urine samples obtained from wild type and null mice were first hydrolysed with Helix Pomatia, extracted with dichloromethane and reconstituted in assay buffer. Aliquots were then assayed using the ELISA technique previously published (Al-Dujaili 2006, Clinica Chimica Acta. 364: 172-179). The assays were validated for specificity, sensitivity, parallelism, accuracy and imprecision. Cross-reactivity with major interfering steroids was minimal: DOC assay (progesterone=0.735% and corticosterone=0.045%), and for B assay (11-dehydro-B=0.006%, cortisol=0.016%, DOC=0.04% and aldosterone=0.14%). Minimum detection limit for DOC ELISA was 2.8 pg/ml (8.5 pmol/l), and for B ELISA was 12.2 pg/ml (0.035 nmol/l). The validity of urinary DOC and B ELISAs were confirmed by the excellent correlation between the results obtained before and after solvent extraction and HPLC separation step (DOC ELISA: Y=1.092X-0.012, R2=0.988, n=42; B ELISA: Y=1.047X-0.226, R2=0.996, n=42). Accuracy studies, parallelism and imprecision data were determined and all found to be satisfactory. Using these assays: mean urinary DOC and B levels in female wild type mice were 0.1960.033 (S.E.M.) and 65.3813.04 nmol/g per day and in null mice were 8.561.27 and 3.6610.48 nmol/g per day respectively. In male mice, DOC and B levels in wild type were 0.0480.14 and 6.060.87 nmol/g per day versus 1.280.298 and 0.6410.112 nmol/g per day in null animals. In conclusion, simple, rapid and sensitive ELISAs have been developed to estimate urinary excretion of DOC and B and the assays can clearly distinguish between urinary steroid excretion of wild type and null mice.
Development of a highly sensitive ELISA for aldosterone in mouse urine: Validation in physiological and pathophysiological states of aldosterone excess and depletion
(2009-04) Al-Dujaili, Emad A. S.; Mullins, L. J.; Bailey, M. A.; Kenyon, C. J.
Background: Clinical studies have established aldosterone as a critical physiological and pathophysiological factor in salt and water homeostasis, blood pressure control and in heart failure. Genetic and physiological studies of mice are used to model these processes. A sensitive and specific assay for aldosterone is therefore needed to monitor adrenocortical activity in murine studies of renal function and cardiovascular diseases. Methods: Antibodies against aldosterone were raised in sheep as previously described. HRP-Donkey-anti-sheep IgG enzyme tracer was produced in our laboratory using the Lightning-Link HRP technique. Aldosterone ELISA protocol was validated and optimised to achieve the best sensitivity. The assay was validated by analysing the urine of mice collected under various experimental conditions designed to stimulate or suppress aldosterone in the presence of other potentially interfering steroid hormones. Results: Cross-reactivity with the steroids most likely to interfere was minimal: corticosterone = 0.0028%, cortisol = 0.0006%, DOC = 0.0048% except for 5-dihydro-aldosterone = 1.65%. Minimum detection limit of this ELISA was 5.2 pmole/L (1.5 pg/mL). The validity of urinary aldosterone ELISA was confirmed by the excellent correlation between results obtained before and after solvent extraction and HPLC separation step (Y = 1.092X + 0.03, R2 = 0.995, n = 54). Accuracy studies, parallelism and imprecision data were determined and all found to be satisfactory. Using this assay, mean urinary aldosterone levels were (i) approximately 60-fold higher in females than males mice; (ii) increased 6-fold by dietary sodium restriction; (iii) increased 10-fold by ACTH infusion and (iv) reduced by >60% in Cyp11b1 null mice. Conclusion: We describe an ELISA for urinary aldosterone that is suitable for repeated non-invasive measurements in mice. Female aldosterone levels are higher than males. Unlike humans, most aldosterone in mouse urine is not conjugated. Increased levels were noted in response to dietary sodium restriction and ACTH treatment. The sensitivity of the assay is sufficient to detect suppressed levels in mouse models of congenital adrenal hyperplasia. 2009 Elsevier Inc. All rights reserved.
Differential effect of polyphenol-rich dark chocolate on glucoregulatory and cardiovascular risk factors on healthy overweight and obese subjects: a randomized clinical trial
(Royal Society of Chemistry, 2012-07) Almoosawi, Suzana; Tsang, Catherine; Ostertag, L. M.; Fyfe, Lorna; Al-Dujaili, Emad A. S.
The association between excess cortisol and various parameters of metabolic syndrome including hypertension, insulin resistance and dyslipidaemia is increasingly recognised. The present single-blind randomised placebo-controlled cross-over study compared the effect of polyphenol-rich dark chocolate (DC) on biomarkers of glucose metabolism, lipid profile, and blood pressure (BP) in females with BMI 25 kg m-2 (n = 21) and females with BMI < 25 kg m-2 (n = 21). Volunteers consumed 20 g of DC containing 500 mg polyphenols or a placebo DC with negligible polyphenol-content daily for 4 weeks, separated by a 2-week washout period. Systolic BP and diastolic BP decreased after 4 weeks of polyphenol-rich DC. Placebo raised fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and salivary cortisol, an effect that was significantly different from polyphenol-rich DC which had a negligible effect on fasting insulin, HOMA-IR and salivary cortisol. Females with BMI 25 kg m-2 responded less favourably to placebo than lean females and consequently had higher fasting insulin and HOMA-IR, in addition to a lower quantitative sensitivity check index (QUICKI) after ingestion of placebo compared to polyphenol-rich DC. No significant changes in lipid profile were observed. This study provides evidence for the metabolic benefits of consuming polyphenol-rich dark chocolate while demonstrating the possibility of adverse effects occurring with polyphenol-poor chocolate placebo.
Does ginseng ingestion influence salivary testosterone and DHEA levels in females
(2007) Al-Dujaili, Emad A. S.; Chalmers, Ruth; Sharp, M.
Ginseng, a traditional herbal adaptogen, historically used in the Far East, has gained popularity in the West for its restorative properties. Ginsenosides, the active component of ginseng are known to exert a variety of actions by targeting 'multireceptor systems' both extracellular and intracellular. As a result many of its physiological effects remain unclear, particularly in humans. This study aims to investigate whether ginseng can influence salivary androgen levels (testosterone and DHEA) in females. Twenty-Four females were recruited for the study and divided into 2 groups (Group 1 aged 20-30 and Group 2 aged 38-50 years). The project has received ethical approval from QMUC ethical committee. Volunteers were asked to maintain a food diary for 48 hours pre and post ginseng consumption and collect 4 salivary samples (after wakening, 0900 hours, 1200 hours and 1700 hours) before and after ingesting 650 mg Korean Gensing per day for 7 days. Testosterone and DHEA were then assayed in all samples by ELISA methods. For the young group: Mean daily salivary testosterone pre-gensing ingestion was 111.266.1 pg/mL and post gensing was 133.680.2 pg/mL (related t-test P=0.091). Mean daily salivary DHEA pre-gensing ingestion was 1.9770.38 ng/mL and post gensing was 2.041.58 ng/mL (related t-test P=0.899). For the older group: Mean daily salivary testosterone pre-gensing ingestion was 56.114.8 pg/mL and post gensing was 65.111.1 pg/mL (related ttest P=0.032). Mean daily salivary DHEA pre-gensing ingestion was 1.020.665 ng/mL and post gensing was 1.721.11 ng/mL (related t-test P=0.034). In conclusion, it appears that ingestion of Korean gensing has significantly increased salivary testosterone and DHEA in the older women (aged 38-50 years old), but there was no significant difference in the level of either steroid in the younger group. These data suggest a role for gensing in modulating salivary androgen levels and that such effect might be more evident in women above the age of 40 years where the levels of androgens, and particularly DHEA start to decline.
Effect of Glycaemic index of the diet on salivary cortisol and testosterone levels in females
(2007) Al-Dujaili, Emad A. S.; Ashmore, Sophie
There has been great interest in the effect of Glycaemic index (GI) of food on weight reduction, obesity, metabolic syndrome and general well being in women. The majority of research into GI was focussed towards improving blood glucose control in diabetes. Also, favourable changes in blood lipids and some beneficial effect in cancers have been reported. The aim of this pilot study is to investigate the impact of ingesting food with varying GI on salivary cortisol and testosterone levels. A cross-over design was adopted and 8 healthy female subjects volunteered for the study (20-23 years old). The project has received ethical approval by QMUC ethical committee. A diet is said to be of low GI if it has a GI of less than 55, medium GI if it has a GI of 56-69, and a high GI if it is 70 or greater. All subjects consumed a low GI or high GI diet for three days each, with a washout period separating the two. Saliva samples at baseline, after the low GI diet, washout period and high GI diet were collected at 4 different times during the day. Salivary cortisol and testosterone concentrations were measured by ELISA methods. GI was significantly different between the low and high GI diets. No significant difference in cortisol concentration was found on either diet. Significantly more testosterone was produced on the low GI diet compared to basal values (related t-test P=0.05) (see Table below). It was found that lower calories were consumed on the low GI diet compared to the high GI diet and the subject's normal diet was very similar to the high GI diet. Steroid Basal Low GI Washout High GI Unit Cortisol 8.834 11.18 9.54 9.19 ng/mL Testosterone 83.71 123.2 111.14 101.15 pg/mL In conclusion, it appears that GI of the diet consumed by females influences a variety of parameters and that a low GI diet might increase salivary testosterone concentrations. --------------------------------------------------------------------------------
Effect of green coffee bean extract and chlorogenic acid consumption on 11_HSD activity in humans and mice
(2009-03) Almoosawi, Suzana; Dickinson, A.; Fyfe, Lorna; Kenyon, C. J.; Al-Dujaili, Emad A. S.
Increased 11_ hydroxysteroid dehydrogenase type 1 (11_HSD1) activity is implicated in the development of the metabolic syndrome. Identifying natural compounds that influence 11_HSD1 activity could lead to novel methods of treating obesity, cardiovascular disease and diabetes. In the present study, we tested the effect of green coffee bean extract (GCBE), rich in chlorogenic acid (CGA), in human volunteers and of CGA in mice on blood pressure (BP), lipid and glucose metabolism. Our hypothesis was that CGA would improve these parameters, by blocking the uptake of microsomal glucose-6-phosphate which in turn would limit the production of co-factor for 11_HSD1 reductase activity. With local Ethics Committee approval, 13 healthy overweight subjects were given GCBE containing 90 mg CGA twice daily for 2 weeks. Urinary 24 h free cortisol was reduced from 1.05230.45 to 0.7630.40 nmol/kg (P=0.07). Free cortisone excretion was reduced from 0.7120.38 to 0.4320.24 nmol/kg (P=0.007). Systolic BP decreased from 119.410.5 to 113.89.1 mmHg (P=0.05). Fasting plasma glucose (P=0.101), diastolic BP (P=0.114), free cortisol:cortisone ratio (P=0.216) and anthropometrical measurement were not affected. In vitro, 11_HSD1 activity (conversion of added cortisone to cortisol) in isolated mouse microsomes was inhibited dose-dependently by CGA. The effects of feeding diet containing 0.15% CGA for 17 days was tested in male C57BL6 mice. Adiposity was unaffected but liver (27.74.9 vs 15.52.2 mg/g, P<0.04) and plasma (1.240.18 vs 0.860.08 mg/ml, P<0.08) triglycerides tended to be reduced. Urinary 24 h cortisol excretion following IP injection of 20 mg/kg cortisone was 30.14.1 vs 24.25.3 nmol/kg (P<0.4) for control and CGA-treated mice. Peak plasma glucose levels in tolerance tests were earlier with CGA treatment although, over a 2 h period, glucose clearance was not affected.
Effect of meal fat content on salivary testosterone and cortisol levels in healthy female volunteers
(2005) Al-Dujaili, Emad A. S.; Bryant, M. L.
The aim of this study was to determine if a change in the amount of fat consumed in the diet influenced female salivary postprandial testosterone and cortisol concentrations and whether any changes affected circadian rhythm. The study was conducted on 9 healthy female subjects aged 21-45 years (BMI mean=22.51.61) and has been approved by the University College Ethical Committee. Over 3 non-consecutive days, each subject consumed 2 meals, lunch and evening dinner, containing either, high fat (40-45% of total energy), low fat (20-25% of total energy), or the subjects usual daily meals. Saliva samples were collected at 11 predetermined times during the challenge days. Testosterone and cortisol levels in each sample were measured by specific and sensitive ELISA methods following ether extraction of saliva samples. Paired t-tests and repeated measures ANOVA were used for statistical analyses. On high fat diet, testosterone levels post lunch rose from a mean of 155 to 307 pg/ml.Testosterone results were significantly higher on the high fat diet compared to usual daily diet (p=0.018 at 30 minutes post-lunch, and p=0.006 at 1 hour post-lunch). Testosterone levels on low and high fat diets differed significantly 30 minutes post-lunch (p <0.05) and 5 minutes pre-dinner (p=0.03). There was a slight rise, though not significant, in testosterone level post dinner (From a mean of 136 to 189 pg/ml, p=0.22) on high fat content compared with a drop on low fat meal (from a mean of 212 pg/ml to 78 pg/ml). Cortisol levels on the low fat meal differed significantly from the high fat meal at1 hour and 2 hours post lunch (p<0.05 and p<0.01 respectively) and 2 hours post-dinner (p=0.041). Mean cortisol level on high fat meal rose from a mean of 3.34 to 4.935 ng/ml post lunch, with a smaller increase after evening meal (from 2.402 to 3.641 ng/ml). The findings of this study indicate that the amount of fat consumed in a meal, can influence postprandial levels of salivary testosterone and cortisol and their circadian rhythm profile. Such an effect on steroid hormones might have an impact on the person's daily activities and general health and wellbeing.
Effect of Polyphenol Supplementation on Memory Functioning in Overweight and Obese Adults: A Systematic Review and Meta-Analysis
(MDPI, 2024-02-06) Farag, Sara; Tsang, Catherine; Al-Dujaili, Emad A. S.; Murphy, Philip N.
Negative health consequences of obesity include impaired neuronal functioning and cell death, thus bringing the risk of impaired cognitive functioning. Antioxidant properties of polyphenols offer a possible intervention for overweight people, but evidence for their effectiveness in supporting cognitive functioning is mixed. This review examined evidence from randomized controlled trials concerning the effect of polyphenols on tasks requiring either immediate or delayed retrieval of learned information, respectively, thus controlling for differences in cognitive processes and related neural substrates supporting respective task demands. Searches of the PubMed/Medline, PsycInfo, and Scopus databases identified 24 relevant primary studies with N = 2336 participants having a BMI ≥ 25.0 kg/m2. The participants’ mean age for the 24 studies exceeded 60 years. Respective meta-analyses produced a significant summary effect for immediate retrieval but not for delayed retrieval. The present findings support a potential positive effect of chronic supplementation with polyphenols, most notably flavonoids, on immediate retrieval in participants aged over 60 years with obesity being a risk factor for cognitive impairment. We recommend further investigation of this potential positive effect in participants with such risk factors. Future research on all populations should report the phenolic content of the supplementation administered and be specific regarding the cognitive processes tested.
Effect of Pomegranate Extract Consumption on Cardiovascular Disease Risk Factors, Stress Hormones, and Quality of Life in Human Volunteers: An Exploratory Randomised, Double-Blind, Placebo-Controlled Trial
(ECronicon, 2015-10-15) Stockton, Angela; Al-Dujaili, Emad A. S.; McDougall, Gordon; Davidson, Isobel; Drummond, Sandra; Wyness, Laura
Background: Pomegranate extract (PE) provides a rich and varied source of biophenols, which can act as powerful antioxidants. The most abundant being ellagitannins, anthocyanins, and ellagic and gallic acid derivatives.. Evidence suggests that pomegranate juice consumption may alleviate cardiovascular disease (CVD) risk factors. This exploratory study investigates the effect of PE consumption on blood pressure (BP), insulin resistance (HOMA-IR), stress hormone levels (cortisol/cortisone) and quality of life in healthy human volunteers. Methods: Seven males and 22 females(n = 29) participated in a double-blind, randomised, placebo-controlled exploratory study (BMI: 25.05 3.91 kg/m_, age: 34.5 13.7 years). All participants consumed either one PE (Pomanox, Pomegreat) or a placebo capsule daily, after a meal, for 4 weeks. Dietary history and habits and the health related Quality of Life questionnaire (Rand 36) were recorded pre- and post-intervention. BP, salivary cortisol and cortisone levels (am, noon, and pm) were assessed by ELISAs, and fasting blood was obtained at baseline and after 4 weeks to compare glucose, insulin and insulin resistance parameters. Results: All participants randomised in the study completed the intervention. Systolic BP was significantly reduced following PE from 120.3 13.3 to 115.6 13.1 mmHg (P = 0.012). There was a reduction in the HOMA-IR levels from2.22 2.62 to 1.61 1.88 (P = 0.045), and glucose, insulin and uric acid all decreased from baseline. No significant changes were recorded in volunteers taking the placebo. PE consumption caused a significant drop of salivary cortisol levels (am; 39.5 19.6%, p < 0.001 and noon; 43.1 32.3%, p = 0.016). The salivary cortisol/cortisone ratio was also significantly reduced (am from 1.11 0.51 to 0.55 0.26, p < 0.001, noon 1.57 0.85 to 0.75 0.72, p < 0.001 and pm; 1.22 0.90 to 0.74 0.59, p = 0.011). Physical (p = 0.018) and social functioning (p = 0.021), pain (p = 0.003), general health (p = 0.008) and overall Quality of Life score (p = 0.007) were significantly improved in those taking the PE capsules. The intervention was delivered successfully with no withdrawals. Conclusions: These results suggest that PE intake rich in biophenols may ameliorate cardiovascular risk factors, reduce stress levels and improve perceived health related quality of life. The reduction in salivary cortisol levels may prove beneficial for people suffering from chronic stress. This exploratory study provides useful information required to conduct a definitive trial.