Trace element status in Saudi patients with established atherosclerosis

BACKGROUND: Traditional coronary risk factors do not fully explain variations in the incidence of cardiovascular disease (CVD). Epidemiological studies have implicated perturbations in selenium, copper, and zinc metabolism in the aetiology of CVD. However, these studies have been principally undertaken in Caucasian populations, in whom trace element intake is generally sufficient. METHOD: We have measured serum and urine selenium, copper, and zinc; and superoxide dismutase, glutathione peroxidase, and lipid peroxide concentrations in 130 Saudi male subjects with established CVD, and 130 age-matched controls. RESULTS: Diabetes mellitus, positive smoking habit (p<0.0001 for both), and hypertension (p<0.05) were more prevalent among CVD patients. Urinary copper (p<0.0001) and zinc (p<0.05) were higher among controls. Serum selenium concentrations were lower among CVD patients (p<0.001), and a high proportion (52%) had selenium levels below 79mug/L compared to controls (22%) (p<0.0001). Conditional logistic regression analysis, showed the characteristics differentiating CVD patients from controls were serum zinc (odds ratio (OR) 0.92, confidence interval (CI) 0.85-0.99, p<0.05), serum copper/zinc ratio (OR 0.31, CI 0.10-0.96), serum selenium (OR 0.07, CI 0.02-0.31, p<0.0001), and urine selenium (OR 3.34, CI 1.40-7.99, p<0.01). CONCLUSION: Measures of trace metals status appear to be associated with the risk of atherosclerosis in a Saudi male population.     

Prognostic Value of Serum Selenium Levels in Alcoholics

In alcoholics, exposure of Kupffer cells to intestinal-borne Gram-negative bacteria increases free radical release, which may, in turn, enhance cytokine secretion, creating a positive feedback loop, which contributes to liver inflammation. Impaired antioxidant mechanisms further aggravates this scenario. Some trace elements, such as selenium, are main cofactors of antioxidant enzymes. Some authors have found low Se levels in alcoholics in relation either with undernutrition, liver dysfunction, or intensity of alcoholism, but in general, Se supplementation has no effect on survival. In this study we measured serum Se in 16 controls and 76 alcoholics, 34 of them cirrhotics, 68 of whom were followed up for a median period of 38 months; 17 died during this period. Se levels were lower in patients than in controls and were related to prothrombin activity and nutritional status, more closely to this last parameter (stepwise logistic regression analysis). Patients who died showed lower Se values than those who survived. Se values over the median were associated with better survival, assessed by Kaplan–Meier curves and log-rank test. However, in multivariate analysis (Cox regression model), prothrombin activity displaced serum Se as a prognostic factor. We conclude that serum Se levels are low in alcoholics; these low values depend more heavily on impaired nutrition but also on liver dysfunction; although low Se levels were associated with a higher mortality, prothrombin activity displaced serum Se when survival was assessed using Cox’s regression model.     

Trace elements (copper,zinc, selenium and molybdenum) as markers in oral sub mucous fibrosis and oral squamous cell carcinoma

Oral cancer is a major cause of cancer morbidity and mortality worldwide and is prevalent in most areas where tobacco related practices are observed. Essential elements play a role in many biochemical reactions as a micro-source and there is growing evidence that their concentrations are altered on the onset and progress of malignant disease. In this study the levels of copper (Cu), zinc (Zn), selenium (Se) and molybdenum (Mo) in serum of patients with oral sub mucous fibrosis (OSMF) (n = 30) and oral squamous cell carcinoma (OSCC) (n = 30); were determined and the alterations of these critical parameters were analyzed in comparison with controls (n = 30) to identify predictors amongst these parameters for disease occurrence and progression. The serum Cu and Zn were established using Flame Atomic Absorption Spectrometry. Serum estimation of Se and Mo was done by graphite furnace atomic absorption spectrometry (GFAAS). Data analysis revealed a marked, progressive and significant increase in Cu levels in precancer (OSMF) and cancer (OSCC) groups as compared to the normal group. The level of Zn in serum was slightly elevated in OSMF and OSCC though not statistically significant. Cu/Zn ratio was slightly but not significantly elevated. Serum levels of Se and Mo were significantly decreased in the precancer and cancer groups as compared to the normals.     

Serum trace mineral variations in Nili-Ravi buffaloes suffering with prepartum vaginal prolapse in two different agro-ecological zones of Punjab, Pakistan

The present study was conducted during 2005 and 2006 on 200 Nili-Ravi buffaloes kept in two agroecological zones (irrigated [zone 1] and rain-fed [zone-2]) of Punjab, Pakistan, with the objective to determine the level of trace minerals (Cu, Fe, Zn, Se) in serum of the buffaloes suffering from vaginal prolapse and to compare them with their healthy counterparts. In each zone 50 buffaloes suffering from prepartum vaginal prolapse during their seventh month of gestation were identified through survey. Vaginal prolapse-affected buffaloes belonging to zone 1 were identified as group VPB1 (N = 50), whereas buffaloes belonging to zone 2 were recognized as VPB2 (N = 50). The buffaloes of control group in zone 1 and zone 2 were identified as NCB1 and NCB2, respectively. The blood samples in all four groups of buffaloes were collected three times, i.e., first when these animals were in the eighth month of gestation, second during the eighth to ninth month of gestation, and finally when these animals were in the ninth or later month of gestation. The mean serum copper concentrations in buffaloes of group VPB1 were significantly lower (P < 0.05) in comparison with NCB1 and NCB2, whereas there were nonsignificant differences (P > 0.05) in copper concentrations between VPB1 and VPB2. There was a significant difference (P < 0.05) of iron concentration in VPB1 compared with NCB1 and NCB2. Similarly, VPB2 also had significantly lower (P < 0.05) iron concentrations compared with NCB1 and NCB2. Serum zinc concentrations were significantly lower (P < 0.05) in animals of the VPB1 group when compared with NCB1 and NCB2. Similarly, lower zinc concentrations were observed in VPB2 in comparison with NCB1 and NCB2. There was significantly lower (P < 0.05) zinc concentration in affected buffaloes (VPB1 and VPB2) from the ninth month of gestation to term when compared with those in the eighth to ninth mo of gestation, and with those not yet in the eighth month of gestation. Serum selenium concentration were significantly higher (P < 0.05) in control group buffaloes (NCB1 and NCB2) in comparison with vaginal prolapse-affected buffaloes (VPB1 and VPB2). During different stages of gestation, mean serum selenium concentrations varied nonsignificantly (P > 0.05) within each group of buffalo. Based on information obtained from this study, it was concluded that the low serum concentration of copper and selenium are linked to increased incidence of vaginal prolapse in buffaloes during the last trimester of gestation.     

Maternal Milk Concentration of Zinc,Iron, Selenium,and Iodine and Its Relationship to Dietary Intakes

The dietary intake of zinc (Zn), iron (Fe), selenium (Se), and iodine (I) of 31 lactating Mexican–American women attending the Hidalgo County WIC program in Rio Grande Valley (RGV), Texas was estimated from 24-h dietary recall interviews. Milk samples were obtained from lactating mothers who had infants 3 months of age and younger. Milk samples were collected in two visits to assess change in breast milk composition after 1–3 months postpartum: group A—after 30–45 days and group B—75–90 days. Dietary intakes indicated that the study participants had significantly inadequate percent energy intakes than the DRI (Dietary Recommended Intakes) percent recommended kilocalorie values but protein intakes were substantially higher than the percent recommended values. The estimated percent Zn, Fe, Se, and I intakes were also significantly lower than the DRI percent recommended values. The lactating mothers consumed significantly less Zn, Se, and I when compared to the Recommended Dietary Allowances (RDA) even though Fe intake was higher than the RDA value. Breast milk concentration of Zn, Fe, and Se were in agreement within the range of representative values for Constituents of Human Milk but I has significantly less concentration than the representative value. There was no statistically significant correlation observed between dietary intake and milk concentration of Zn, Fe, Se, and I. This study compares the estimated dietary intake of zinc, iron, selenium, and iodine to the concentration of these trace elements in the maternal milk of lactating women of Mexican–American heritage who attend the Rio Grande Valley WIC clinic.     

Exploiting genotypic variation in plant nutrient accumulation to alleviate micronutrient deficiency in populations

More than 2 billion people consume diets that are less diverse than 30 years ago, leading to deficiencies in micronutrients, especially iron (Fe), zinc (Zn), selenium (Se), iodine (I), and also vitamin A. A strategy that exploits genetic variability to breed staple crops with enhanced ability to fortify themselves with micronutrients (genetic biofortification) offers a sustainable, cost-effective alternative to conventional supplementation and fortification programs. This is more likely to reach those most in need, has the added advantages of requiring no change in current consumer behaviour to be effective, and is transportable to a range of countries. Research by our group, along with studies elsewhere, has demonstrated conclusively that substantial genotypic variation exists in nutrient (e.g. Fe, Zn) and nutrient promotor (e.g. inulin) concentrations in wheat and other staple foods. A rapid screening technique has been developed for lutein content of wheat and triticale, and also for pro-vitamin A carotenoids in bread wheat. This will allow cost-effective screening of a wider range of genotypes that may reveal greater genotypic variation in these traits. Moreover, deeper understanding of genetic control mechanisms and development of molecular markers will facilitate breeding programs. We suggest that a combined strategy utilising plant breeding for higher micronutrient density; maximising the effects of nutritional promoters (e.g. inulin, vitamin C) by promoting favourable dietary combinations, as well as by plant breeding; and agronomic biofortification (e.g. adding iodide or iodate as fertiliser; applying selenate to cereal crops by spraying or adding to fertiliser) is likely to be the most effective way to improve the nutrition of populations. Furthermore, the importance of detecting and exploiting beneficial interactions is illustrated by our discovery that in Fe-deficient chickens, circulating Fe concentrations can be restored to normal levels by lutein supplementation. Further bioavailability/bioefficacy trials with animals and humans are needed, using varying dietary concentrations of Fe, Zn, carotenoids, inulin, Se and I to elucidate other important interactions in order to optimise delivery in biofortification programs.     

Zinc and Selenium Nutritional Status in Vegetarians

A vegetarian diet may have beneficial effects on human health, however when it is not well-balanced may be deficient in some nutrients, as minerals for example. The aim of the present study was to assess the nutritional status of zinc and selenium in vegetarians in the city of São Paulo. A cross-sectional study was performed, and the inclusion criteria were age ≥ 18 years, both gender, no use of food or pharmaceutical supplements. Thirty vegetarian, of both genders, mean age of 27 years and 4,5 years of vegetarianism had performed the study, and their mean BMI was 21,5. Zinc plasma concentration was 71 and 62,5 μg/dL for men and women and erythrocyte concentration was 37 μg/gHb for both genders. Selenium concentration was 73,5 and 77,3 μg/L in plasma and 51,4 and 66,9 μg/L in erythrocytes for men and women, respectively. These biochemical values show that, according to the references, selenium blood levels are adequate and zinc concentration in erythrocytes is deficient in the studied population. For this reason, vegetarians should be constantly assessed and receive nutritional support to reduce the effects of inadequate zinc status.     

Serum Zinc and Copper Levels in Ischemic Cardiomyopathy

Changes in the copper (Cu) and zinc (Zn) concentrations have been reported previously in ischemic cardiomyopathy (ISCMP). Due to controversial results, the aims of this study were to compare levels of Cu, Zn, and Zn/Cu ratio of ISCMP patients with healthy volunteers and also to investigate the possible relationship between trace elements status in ISCMP patients with the severity of clinical disease based on the New York Heart Association (NYHA) classification. The subjects of this study consisted of 30 ISCMP and 27 healthy volunteers. ISCMP was diagnosed with a history of previous myocardial infarction and also coronary artery disease was confirmed by coronary angiography. Exclusion criteria were renal or hepatic insufficiency, alcohol usage, and intake of supplements containing Cu or Zn within 1 week. Cu and Zn levels have been assayed with atomic absorption spectrophotometry. Statistical analysis was performed with the SPSS 10 software using independent sample t test for comparing the levels of Cu and Zn between ISCMP and normal subjects. The mean Cu level of the ISCMP group (1.54 ± 0.52 mg/L) was significantly more than the Cu levels of the healthy volunteers (1.31 ± 0.24 mg/L; p = 0.048). The mean Zn levels of the ISCMP and healthy volunteers were 1.05 ± 0.28 and 1.12 ± 0.42, respectively, without any significant difference between groups. There was a trend for higher Cu level, lower Zn level, and lower Zn/Cu ratio in NYHA III patients in comparison with NYHA II group. Considering the results of this study, Cu may have a role in the development of ISCMP. Interventions such as administration of Cu chelators to relieve the symptoms or to decrease the progression of ISCMP is needed to be examined in large clinical trials. In this study, the Zn level of ISCMP patients was not significantly different in comparison with the healthy volunteers.     

Bioinorganic chemistry aspects of the inhibition of thyroid hormone biosynthesis by anti-hyperthyroid drugs

In this paper, the synthesis and characterization of thiones and selones having N,N-disubstituted imidazole are described. Experimental and theoretical studies were performed on a number of selones, which suggest that these compounds exist as zwitterions in which the selenium atom carries a large negative charge. The structures of selones were studied in solution by ⁷⁷Se NMR spectroscopy and the ⁷⁷Se NMR chemical shifts for the selones show large upfield shifts in the signals, confirming the zwitterionic structure of the selones in solution. The thermal isomerization of some S- and Se-substituted methyl and benzyl imidazole derivatives to produce the thermodynamically more stable N-substituted derivatives are described. A structure-activity correlation was attempted on the inhibition of LPO-catalyzed oxidation and iodination reactions by several thiouracil compounds, which indicate that the presence of an n-propyl group in PTU is important for an efficient inhibition. In contrast to the S- and Se-substituted derivatives, the selones produced by thermal isomerization exhibited efficient inhibition, indicating the importance of reactive selone (zwitterionic) moiety in the inhibition. The inhibition data on carbimazole (CBZ) support the assumption that CBZ acts as a prodrug, requiring a conversion to methimazole (MMI) for its inhibitory action on thyroid peroxidase.     

Protective Effects of Selenium,Zinc, or Their Combination on Cadmium-Induced Oxidative Stress in Rat Kidney

The present study was conducted to investigate whether the combined treatment with Se and Zn offers more beneficial effects than that provided by either of them alone in reversing Cd-induced oxidative stress in the kidney of rat. For this purpose, 30 adult male Wistar albino rats, equally divided into control and four treated groups, received either 200 ppm Cd (as CdCl₂), 200 ppm Cd + 500 ppm Zn (as ZnCl₂), 200 ppm Cd + 0.1 ppm Se (as Na₂SeO₃), or 200 ppm Cd + 500 ppm Zn + 0.1 ppm Se in their drinking water for 35 days. The results showed that Cd treatment decreased significantly the catalase (CAT) and glutathione peroxidase (GSH-Px) activities, whereas the superoxide dismutase (SOD) activity and the renal levels of lipid peroxidation (as malondialdehyde, MDA) were increased compared to control rats. The treatment of Cd-exposed rats with Se alone had no significant effect on the Cd-induced increase in the MDA concentrations but increased significantly the CAT activities and reversed Cd-induced increase in SOD activity. It also partially prevented Cd-induced decrease in GSH-Px activity. The treatment of Cd-exposed animals with Zn alone increased significantly the CAT activity and partially protected against Cd-induced increase in the MDA concentrations, whereas it had no significant effect on the Cd-induced increase in SOD activity and decrease in GSH-Px activity. The combined treatment of Cd-exposed animals with Se and Zn was more effective than that with either of them alone in reversing Cd-induced decrease in CAT and GSH-Px activities and Cd-induced increase in MDA concentrations. Results demonstrated beneficial effects of combined Se and Zn treatment in Cd-induced oxidative stress in kidney and suggest that Se and Zn can have a synergistic role against Cd toxicity. I. Messaoudi and J. El Heni have equally contributed to this work.