Trace elements and bone metabolism

Doping β-TCP as a Strategy for Enhancing the Regenerative Potential of Composite β-TCP-Alkali-Free Bioactive Glass Bone Grafts. Experimental Study in Rats

The present work aims at evaluating the potential gains derived from partially replacing calcium in resorbable β-tricalcium phosphate (β-TCP) by two different molar percentages of strontium (5, 10) and zinc (1, 2), concomitantly with a fixed molar percentage (0.5) of manganese. Synthetic granular composite bone filling grafts consisting of doped β-TCP and an alkali-free bioactive glass were prepared and implanted in ~4 mm diameter bone defects drilled in the calvaria of Wistar rats used as animal models. The animals were sacrificed after 9 weeks of implantation and the calvaria was excised. Non-manipulated bone was used as positive control, while empty defects were used as a negative control group. The von Kossa staining revealed an enhanced new bone formation with increasing doping levels, supporting the therapeutic effects exerted by the doping elements. The percentage of newly formed bone was similar when the defects were filled with autologous bone, BG (previous results) or 3TCP2/7BG, which indicates that the latter two are excellent candidates for replacement of autologous bone as bone regeneration material. This finding confirms that doping with suitable doses of therapeutic ions is a good strategy towards transposing the bone graft materials to biomedical applications in humans.

Copper, magnesium, zinc and calcium status in osteopenic and osteoporotic post-menopausal women

Copper, magnesium, zinc and calcium status were measured in postmenopausal women with osteoporosis (n = 23) and osteopenia (n = 28) as classified on the basis of the T-score of the femur neck and dual energy X-ray absorptiometry results. Anthropometric indices, dietary intake and serum copper, magnesium, zinc and calcium were assessed. The results of our study showed that the mean dietary intake of magnesium, zinc and calcium in post-menopausal women with low bone density were significantly lower than recommended dietary allowance. The mean serum levels of zinc (P = 0.001) and copper (P = 0.000) were significantly lower than normal range and 40.4% of this participants had serum magnesium levels lower than normal range. No statistically significant differences were observed between the osteopenic and osteoporotic groups with respect to serum levels and dietary intakes of copper, calcium, magnesium and zinc. Due to the mineral deficiency in post-menopausal women with low bone density and the key role of minerals on bone health, supplementation with magnesium, calcium, zinc and perhaps copper recommended.

Estimation of toxic elements in the samples of different cigarettes and their effect on the essential elemental status in the biological samples of Irish smoker rheumatoid arthritis consumers

Cigarette smoking interferes with the metal homeostasis of the human body, which plays a crucial role for maintaining the health. A significant flux of heavy metals, among other toxins, reaches the lungs through smoking. In the present study, the relationship between toxic element (TE) exposure via cigarette smoking and rheumatoid arthritis incidence in population living in Dublin, Ireland, is investigated. The trace {zinc (Zn), copper (Cu), manganese (Mn), and selenium (Se)} and toxic elements arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) were determined in biological (scalp hair and blood) samples of patients diagnosed with rheumatoid arthritis, who are smokers living in Dublin, Ireland. These results were compared with age- and sex-matched healthy, nonsmoker controls. The different brands of cigarette (filler tobacco, filter, and ash) consumed by the studied population were also analyzed for As, Cd, Hg, and Pb. The concentrations of trace and TEs in biological samples and different components of cigarette were measured by inductively coupled plasma mass spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials. The recovery of all the studied elements was found to be in the range of 96.4-99.8% in certified reference materials. The filler tobacco of different branded cigarettes contains Hg, As, Cd, and Pb concentrations in the ranges of 9.55-12.4 ng, 0.432-0.727 μg, 1.70-2.12 μg, and 0.378-1.16 μg/cigarette, respectively. The results of this study showed that the mean values of As, Cd, Hg, and Pb were significantly higher in scalp hair and blood samples of rheumatoid arthritis patients as compare to healthy controls, while Zn, Cu, Mn, and Se concentrations were found to be lower in rheumatoid arthritis patients, the difference was significant in the case of smoker patients (p<0.001). The levels of four toxic elements were 2-3-folds higher in scalp hair and blood samples of nonrheumatoid arthritis smoker subjects as compared to nonsmoker controls. The high exposure of toxic metals as a result of cigarette smoking may be synergistic with risk factors associated with rheumatoid arthritis.

Preservation of bone structure and function by Lithothamnion sp. derived minerals

Progressive bone mineral loss and increasing bone fragility are hallmarks of osteoporosis. A combination of minerals isolated from the red marine algae, Lithothamnion sp. was examined for ability to inhibit bone mineral loss in female mice maintained on either a standard rodent chow (control) diet or a high-fat western diet (HFWD) for 5, 12, and 18 months. At each time point, femora were subjected to μ-CT analysis and biomechanical testing. A subset of caudal vertebrae was also analyzed. Following this, individual elements were assessed in bones. Serum levels of the 5b isoform of tartrate-resistant acid phosphatase (TRAP) and procollagen type I propeptide (P1NP) were also measured. Trabecular bone loss occurred in both diets (evident as early as 5 months). Cortical bone increased through month 5 and then declined. Cortical bone loss was primarily in mice on the HFWD. Inclusion of the minerals in the diet reduced bone mineral loss in both diets and improved bone strength. Bone mineral density was also enhanced by these minerals. Of several cationic minerals known to be important to bone health, only strontium was significantly increased in bone tissue from animals fed the mineral diets, but the increase was large (5-10 fold). Serum levels of TRAP were consistently higher in mice receiving the minerals, but levels of P1NP were not. These data suggest that trace minerals derived from marine red algae may be used to prevent progressive bone mineral loss in conjunction with calcium. Mineral supplementation could find use as part of an osteoporosis-prevention strategy.

Association between essential trace and toxic elements in scalp hair samples of smokers rheumatoid arthritis subjects

The incidence of rheumatoid arthritis (RA) has been increased among people who possess habit of tobacco smoking. In the present study, zinc (Zn), copper (Cu), manganese (Mn), lead (Pb) and cadmium (Cd) were determined in scalp hair samples of smokers and nonsmokers RA patients, residents of Dublin, Ireland. For comparison purposes scalp hair samples of age and sex matched healthy smokers and nonsmokers were also analyzed. The concentrations of understudied elements were measured by inductive coupled plasma atomic emission spectrophotometer, prior to microwave assisted acid digestion. The validity and accuracy of methodology was checked using certified reference material (NCS ZC 81002b) and by the conventional wet acid digestion method on the same certified reference material and on real samples. The mean hair Zn, Cu and Mn contents were significantly lower in smokers and nonsmokers RA patients as compared to healthy individuals (p=0.01-0.001). Whereas the concentrations of Cd and Pb were significantly higher in scalp hair samples of RA patients of both group (p<0.001). The referent smokers have high level of Cd and Pb in their scalp hair samples as compared to those had not smoking tobacco (p<0.01). The ratio of Cd and Pb to Zn, Cu and Mn in scalp hair samples was also calculated. The Cd/Zn ratio was higher in smoker RA patients with related to nonsmoker RA and referents. This study is compelling evidence in support of positive associations between toxic elements, cigarette smoking, deficiency of essential trace elements and risk of arthritis.