Wissam H. Ibrahim

Effect of Ramadan Fasting on Markers of Oxidative Stress and Serum Biochemical Markers of Cellular Damage in Healthy Subjects

Background/Aims: Ramadan is a holy month for Muslims during which they abstain from eating, drinking and smoking from dawn to sunset. This makes Ramadan a unique model for studying the effects of altered meal patterns in humans. The aim of this study was to determine the effect of Ramadan fasting on markers of oxidative stress and serum biochemical markers of cellular damage in healthy subjects. Methods: Fourteen healthy volunteers (9 men and 5 women aged 25–58 years) who fasted during Ramadan participated in the study. Blood sampling was conducted 2 days before Ramadan and on days 14 and 28 of Ramadan. The following were measured: (1) in serum, malondialdehyde (MDA), aspartate aminotransferase, alanine aminotransferase, creatine kinase, alkaline phosphatase, lactate dehydrogenase, blood urea nitrogen, total proteins, uric acid, albumin, glucose, triglycerides and total cholesterol; (2) in plasma, protein-bound carbonyls, α-tocopherol, γ-tocopherol, retinol, vitamin C and carotenoids, and (3) in erythrocytes, MDA, glutathione, glutathione peroxidase and catalase. Results: Erythrocyte MDA, serum glucose and triglycerides and plasma total carotenoids were significantly lower (p < 0.05) on day 28 of Ramadan compared to before Ramadan. The rest of the variables were not significantly altered by Ramadan fasting. Conclusion: The results obtained indicate that with the exception of a slight reduction in lipid peroxidative damage in erythrocytes, Ramadan fasting does not alter oxidative stress parameters or biochemical markers of cellular damage in healthy subjects.

Camel milk lactoferrin reduces the proliferation of colorectal cancer cells and exerts antioxidant and DNA damage inhibitory activities

Lactoferrin (Lf), the main iron-binding protein of milk, has biological activities. We have evaluated the potential of camel milk lactoferrin for its ability to inhibit the proliferation of the colon cancer cell line, HCT-116, in vitro, DNA damage and its antioxidant activities for the first time. The antioxidant capacity of Lf was evaluated by different assays, including ferric-reducing/antioxidant power assay (FRAP), free radical-scavenging activity (DPPH), nitric oxide (NO) radical-scavenging assay, total antioxidant activity and DNA damage, compared with vitamin C and rutin.

Nutritional quality evaluation of eighteen date pit varieties

The pits from date palm fruits (Phoenix dactylifera L.) are nutrient dense but the nutrient composition across varieties has not been extensively studied. In the present study, 18 leading varieties of date pits from date fruits cultivated in the United Arab Emirates (Khalas, Barhe, Lulu, Shikat alkahlas, Sokkery, Bomaan, Sagay, Shishi, Maghool, Sultana, Fard, Maktoomi, Naptit Saif, Jabri, Kodary, Dabbas, Raziz and Shabebe) were analyzed and compared for their chemical and physical properties. Dietary fiber, proximate analysis, micronutrients, and physical properties (weight, length, and density) were determined. Significant differences (P<0.05) in the measured parameters were observed among the different varieties. The results show that date pits, depending on the variety, contain significant but quite variable amounts of macronutrients and micronutrients, but all varieties are excellent sources of dietary fiber and may therefore serve as important constituents of functional foods.

Antioxidant and oxidative status in tissues of manganese superoxide dismutase transgenic mice.

Manganese superoxide dismutase (Mn-SOD) plays an important role in attenuating free radical-induced oxidative damage. The purpose of this research was to determine if increased expression of Mn-SOD gene alters intracellular redox status. Twelve week old male B6C3 mice, engineered to express human Mn-SOD in multiple organs, and their nontransgenic littermates were assessed for oxidative stress and antioxidant status in heart, brain, lung, skeletal muscle, liver, and kidney. Relative to their nontransgenic littermates, transgenic mice had significantly (p <.01) higher activity of Mn-SOD in heart, skeletal muscle, lung, and brain. Copper, zinc (Cu,Zn)-SOD activity was significantly higher in kidney, whereas catalase activity was lower in brain and liver. The activities of selenium (Se)-GSH peroxidase and non-Se-GSH peroxidase, and levels of vitamin E, ascorbic acid and GSH were not significantly different in any tissues measured between Mn-SOD transgenic mice and their nontransgenic controls. The levels of malondialdehyde were significantly lower in the muscle and heart of Mn-SOD mice, and conjugated dienes and protein carbonyls were not altered in any tissues measured. The results obtained showed that expression of human SOD gene did not systematical alter antioxidant systems or adversely affect the redox state of the transgenic mice. The results also suggest that expression of human SOD gene confers protection against peroxidative damage to membrane lipids.

Effect of date seeds on oxidative damage and antioxidant status in vivo

BACKGROUND Date seeds have been shown to contain high amounts of antioxidants. However, in vivo studies on date seeds are lacking. Therefore the purpose of this study was to determine the effect of date seeds on oxidative damage and antioxidant status in vivo. Male Wistar rats were fed a basal diet containing 0, 70 or 140 g kg(-1) date seeds for 30 days. All three diets were isonitrogenous and isocaloric. Indication of oxidative damage was assessed in the liver and serum, and antioxidant status was assessed in the liver. Serum biochemical parameters, including indicators of tissue cellular damage and complete blood count with differential, were also determined. RESULTS The results showed that date seeds significantly (P<0.05) reduced liver and serum malondialdehyde (a lipid peroxidative damage product) and serum lactate dehydrogenase and creatine kinase. Liver antioxidants (vitamin E, vitamin C, glutathione, superoxide dismutase, glutathione peroxidase and catalase), complete blood count with differential and other serum biochemical parameters assessed were not significantly altered by date seeds. CONCLUSION The results obtained suggest a protective effect of date seeds against in vivo oxidative damage, possibly through the action of their bioactive antioxidants.

Physicochemical and biochemical properties of honeys from arid regions

This study was conducted to evaluate the quality of 11 honeys from arid regions for first time, and compare it with 5 different honeys from non-arid regions. Mean values obtained for physicochemical parameters were: pH 4.76 ± 0.55; 17.32 ± 1.8% moisture; 80.95 ± 1.60 °Brix sugar; 69.05 ± 4.41% total sugar; 413.81 ± 178.48 μS cm(-1) electrical conductivity; 17.58 ± 7.68 meq/kg free acidity; 11.05 ± 3.18 meq/kg lactonic acidity; 28.63 ± 9.6 meq/kg total acidity; 12.66 ± 20.39 mg/kg HMF; 0.58 ± 0.03 water activity; and 0.98 ± 0.62 colour intensity. Potassium was the major mineral (1760.54 ± 685.24 mg/kg). All the samples showed considerable significant variations with reference to their physicochemical and biochemical properties, moreover, the total free amino acids and total carotenoids were 61.13 ± 63.16 mg/100g and 4.07 ± 10.05 μg/100g respectively. Acrylamide was detected only in one sample at 2.39 ± 0.22 μg/kg.

Polyphenolic compounds in date fruit seed (Phoenix dactylifera): characterisation and quantification by using UPLC-DAD-ESI-MS.

BACKGROUND Date fruit seeds have been demonstrated to possess high antioxidant activities due to their high content of flavonoids and phenolic compounds. The objective of this work was to identify and quantify the phenolic composition of date seeds. METHODS Two UPLC-DAD-ESI-MS analyses were performed on the seed of the Khalas variety as follows: (1) an analysis of simple phenolic compounds [phenolic acids, hydroxycinnamic acids, flavonols, flavones, flavan-3-ols (monomers, dimers and trimers)]; and (2) an analysis of all flavan-3-ols (monomers, and proanthocyanidin oligomers and polymers) after depolymerisation. RESULTS The amount of total phenolic compounds before depolymerisation was found to be 2.194 ± 0.040 g kg(-1) date seed. The analysis of flavan-3-ol monomers and constitutive units of proanthocyanidins after depolymerisation revealed 50.180 ± 1.360 g kg(-1) flavan-3-ols with 46.800 ± 1.012 g kg(-1) epicatechin and 3.380 ± 0.349 g kg(-1) catechin. CONCLUSION The results indicate that date seeds are a very rich source of bioactive compounds, thus constituting strong candidates for functional food additives and nutraceuticals.

Bioactive components, antioxidant and DNA damage inhibitory activities of honeys from arid regions

Honey serves as a good source of natural antioxidants, which are effective in reducing the risk of occurrence of several diseases. This study was undertaken to address the limited knowledge regarding the polyphenolic content, antioxidant and DNA damage inhibitory activities of honeys produced in arid regions and compare them with well-recognized honeys from non-arid regions. Different types of honey were assessed for their contents of total phenolics, total flavonoids, and certain types of phenolic compounds. The antioxidant capacity of honey was evaluated by ferric-reducing/antioxidant power assay (FRAP), free radical-scavenging activity (DPPH), nitric oxide (NO) radical-scavenging assay, total antioxidant activity, and DNA damage. Results clearly showed significant differences among honeys with all the evaluated parameters. Results also showed that one or more types of honey from arid regions contained higher levels of phenolic compounds, free radical-scavenging activities, or DNA damage inhibitory activities compared with the evaluated honeys from non-arid regions.

Oxidative damage and inflammation in obese diabetic Emirati subjects supplemented with antioxidants and B-vitamins: a randomized placebo-controlled trail

BackgroundObesity and related morbidities are reaching epidemic proportions in the Arab populations. Possible mechanisms that link obesity/visceral fat to diabetes and cardiovascular (CVD) complications include inflammation and increased oxidative stress. The aim of this study is to test whether supplementary antioxidants with B-group vitamins enhance antioxidant capacity and/or mitigate oxidative damage and subclinical inflammation in obese diabetic patients.MethodsHundred diabetic patients were randomly assigned to receive either oral dose of daily B-group vitamins (1.67 mg folic acid, 1.67 mg vitamin B-2, 20 mg vitamin B-6, 0.134 mg vitamin B-12) and antioxidant vitamins (221 mg of α-tocopherol and 167 mg of vitamin C) [n = 50], or an identical placebo [n = 50] daily for 90 days. Blood was obtained before treatment, and after 90 days for measurements of plasma antioxidant vitamins status, markers of oxidative damage [malondialdehyde (MDA) and protein carbonyls] and inflammation (C-Reactive Proteins [CRP], IL6 & TNFα).ResultsSupplementation with antioxidant and B-group vitamins increased plasma concentration of vitamin E and folate and reduced homocysteine in the intervention groups compared with the placebo group. Vitamin B12 improved in the supplement group compared with the decline seen in the placebo group however, this did not reach statistical significance. Vitamin C declined in both groups but more so in the intervention group. Both MDA and Protein carbonyls increased in both the supplement and the placebo group. IL6 concentration increased in both groups but less so in the supplement group (p = 0.023). TNF showed more pronounced decline in the supplement group compared with the placebo group but the difference between cumulative changes did not reach statistical significance (p = 0.204). CRP concentrations declined in the supplement group in contrast to the rise seen in the placebo group however, the difference between cumulative changes was not statistically significant (p = 0.205).ConclusionsAntioxidants supplementation with B-group vitamins enhances antioxidant capacity, and may have an anti-inflammatory effect in obese diabetic patients.

Mitochondrial superoxide mediates labile iron level: evidence from Mn-SOD-transgenic mice and heterozygous knockout mice and isolated rat liver mitochondria

Superoxide is the main reactive oxygen species (ROS) generated by aerobic cells primarily in mitochondria. It is also capable of producing other ROS and reactive nitrogen species (RNS). Moreover, superoxide has the potential to release iron from its protein complexes. Unbound or loosely bound cellular iron, known as labile iron, can catalyze the formation of the highly reactive hydroxyl radical. ROS/RNS can cause mitochondrial dysfunction and damage. Manganese superoxide dismutase (Mn-SOD) is the chief ROS-scavenging enzyme and thereby the primary antioxidant involved in protecting mitochondria from oxidative damage. To investigate whether mitochondrial superoxide mediates labile iron in vivo, the levels of labile iron were determined in the tissues of mice overexpressing Mn-SOD and heterozygous Mn-SOD-knockout mice. Furthermore, the effect of increased mitochondrial superoxide generation on labile iron levels was determined in isolated rat liver mitochondria exposed to various electron transport inhibitors. The results clearly showed that increased expression of Mn-SOD significantly lowered the levels of labile iron in heart, liver, kidney, and skeletal muscle, whereas decreased expression of Mn-SOD significantly increased the levels of labile iron in the same organs. In addition, the data showed that peroxidative damage to membrane lipids closely correlated with the levels of labile iron in various tissues and that altering the status of Mn-SOD did not alter the status of other antioxidant systems. Results also showed that increased ROS production in isolated liver mitochondria significantly increased the levels of mitochondrial labile iron. These findings constitute the first evidence suggesting that mitochondrial superoxide is capable of releasing iron from its protein complexes in vivo and that it could also release iron from protein complexes contained within the organelle.