PIXE analysis of some medicinal plants used in cleaning teeth in southwestern Nigeria.

Sixteen medicinal plants used for cleaning teeth in southwestern Nigeria were analyzed using the particle-induced X-ray emission (PIXE) technique. These medicinal plants have other therapeutic uses, but the emphasis and main focus were on their beneficial effects on human teeth. PIXE measurements were carried out using 1.8 MeV collimated proton beam from the 2.5 MV AN 2000 Van de Graaff accelerator at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padova Italy. The results showed the presence of 18 different elements at different concentrations, 2 plants had traces of gold, and none of the plants contained any toxic heavy metals. The metabolic roles of the detected elements were discussed especially as they affected the formation, growth, development, and protection of human teeth. The results of this study are presented and discussed.

Evaluation of Nigerian animal feeds by particle-induced X-ray emission.

There is need to evaluate the locally available animal feeds in Nigeria so as to be able to combine them in acceptable proportions to the animals to achieve the desired growth rate. The technique of particle-induced X-ray emission (PIXE) was employed for the evaluation of these locally available animal feeds, which include Panicum maximum (Guinea grass), Cynodon plectostachyum (grass), Leucaena leucephala (legume), Calopogonium mucunoides (legume), Gliricidia sepium (legume), Euphorbia polychrome (legume), Pueraria phaseloides (legume), and Centrosema pubescens (legume). The proton beam delivered by the 2.5-MV AN 2,000 Van de Graaff accelerator at the International Centre for Theoretical Physics Laboratori Nazionali di Legnaro (LNL), Padova, Italy was used for the PIXE measurements. Twenty-one different elements were detected at various concentrations and their nutritional effects on different animals are discussed.

PIGE-PIXE analysis of medicinal plants and vegetables of pharmacological importance.

PIGE and PIXE techniques were employed to the study of elemental constituents of some traditional medicinal plants generally used in curing many diseases and ailments in southwestern Nigeria. Analyses were also carried out on commonly edible vegetables of medicinal and pharmacological importance. PIGE measurements were carried out using 3.5-MeV collimated protons from the 7 mV CN Van-de-Graaff accelerator of INFN, LNL, Legnaro (Padova), Italy, whereas the PIXE measurements were carried out using 1.8 MeV from the 2.5 MV AN 2000 Van-de-Graaff accelerator of the same laboratory. The results show that many of the medicinal plants contain elements of cardinal importance in human metabolism. The results from the vegetables also show the presence of vital elements that are needed for growth and development. In addition, some of the toxic elements, which include As, Cd, Hg, and so forth, were not detected. However, some of the recipes contain trace amounts of Pb at very low concentrations. This calls for proper control of dose rates in some samples to prevent the attendant negative cumulative effects.

Selenium status and plasma glutathione peroxidase in patients with IgA nephropathy.

The abnormal proliferation of mesangial cells with IgA deposition in the glomeruli characterizes primitive mesangial glomerulonephritis (IgA nephropathy, IgAN); this disease reduces the normal renal parenchyma while renal function becomes progressively impaired. The possible role of selenium has never been considered in evaluating factors involved in the pathogenesis of IgAN. In this work we compared the Se status of 14 IgAN patients (8 with normal renal function, IgAN NRF; 6 with impaired renal function, IgAN IRF) to that of 14 normal individuals (CG NRF) before and after an oral supplementation with selenite (0.13 mol Se/kg b.w./day for 60 days). The following indices of Se status were measured: Se in plasma and urine samples by PIXE; glutathione peroxidase activity in the cytosol of platelets (PLTs-GSH-Px) and of erythrocytes (RBCs-GSH-Px). Both concentrations and activities of plasma glutathione peroxidase (pl-GPx), a selenoenzyme mainly synthesized in and secreted by the kidney, were measured in plasma samples and results compared among groups. IgAN patients showed lower pl-Se and lower activities of selenoenzymes than normal controls before Se supplementation (p < 0.001). These findings suggest that an impaired Se status coexisted with the proliferation of mesangial cells in patients. Selenite induced PLTs-GSH-Px activity in all individuals (p < 0.001), but no variation was observed in RBCs-GSH-Px activity or in the concentration of pl-GPx in the plasma. On the other hand, selenium induced pl-GPx activity in CG NRF (p < 0.001) and in IgAN NRF (p < 0.01), but poorly stimulated pl-GPx activity in IgAN IRF (p = n.s.). However, only 17% and 25% of the pl-GPx activity of normal controls was measured in the plasma of IgAN IRF and IgAN NRF patients, respectively (p < 0.001). In conclusion, selenite only partially restored a normal Se status in patients whose low pl-GPx activity probably reflects an impaired synthesis of this protein as a consequence of reduced normal functioning of the parenchyma in kidneys affected by IgA nephropathy.

Plasma selenium and glutathione peroxidase activities in individuals living in the Veneto region of Italy.

In order to assess the Se status in individuals living in the Veneto region, a series of related measurements was performed. These included plasma selenium by PIXE and glutathione-peroxidase (GSH-Px) activities in plasma, red blood cells and platelets. Individuals were either normals or people suffering from various liver diseases. Moreover, an oral supplement of sodium selenite was given to 13 patients suffering from stable chronic renal failure (CRF) in parallel to 26 normals: data on plasma GSH-Px and on serum creatinine and creatinine clearance were collected either before or after supplementation. Results were in support of a relatively low selenium status: mean +/- SD plasma Se values of normals (0.82 +/- 0.17mumol/L, n = 82) were comparable to data observed in European regions where Se deficiency was already known. Even lower values were observed in those with liver diseases. Among enzyme activities, the distribution of the data of platelet GSH-Px was in further support of low Se status in the evaluated individuals. After Se supplementation, both normals and CRF patients showed a significant increase in the creatinine clearance, reflecting an improvement of the glomerular filtration rate. We suggest that more extensive surveys of the Se status should be carried out in Italy; moreover, Se supplementation may be advisable in individuals affected with moderate impairment of renal function.

Selenium and glutathione peroxidase variations induced by polyunsaturated fatty acids oral supplementation in humans.

Serum and erythrocyte selenium, erythrocyte and platelet glutathione-peroxidase (GSH-Px) activities, and erythrocyte reduced glutathione (GSH) content were measured in 25 healthy adult individuals before and after daily supplementation with 20 ml of fish oil for 10 weeks. Serum-Se decreased from 0.83 +/- 0.01 mumol/l to 0.75 +/- 0.02 mumol/l (mean +/- S.E.M.) (P less than 0.01); erythrocyte-Se decreased from 4.39 +/- 0.17 nmol/g hemoglobin (Hb) to 2.83 +/- 0.15 nmol/g (P less than 0.001). GSH-Px activities increased both in erythrocytes (6.93 +/- 0.24 iu/g vs 8.18 +/- 0.27 iu/g Hb, P less than 0.01) and in platelets (69.2 +/- 2.8 iu/g vs 90.9 +/- 3.6 iu/g protein, P less than 0.001). The concentration of GSH in erythrocytes fell from 9.56 +/- 0.29 mumol/g Hb to 5.90 +/- 0.30 mumol/g Hb (P less than 0.001). The effects on plasma lipids were evident only for triglycerides (before 1.96 +/- 0.16 mmol/l, after 1.75 +/- 0.14 mmol/l, P less than 0.001). We hypothesise the enrichment of erythrocyte and platelet membranes with polyunsaturated fatty acids (PUFAs), following fish oil intake, can generate increased amounts of lipid peroxides and thus allosterically activate GSH-Px: with time this is harmful for the integrity of the enzyme molecule and Se release may result. We suggest that the Se status of individuals given PUFAs is assessed before and during intake; Se supplements should only be given when serum and/or erythrocyte Se are reduced.

Selenium supplementation increases renal glomerular filtration rate.

Selenium (Se) is a trace element variously distributed in the human body and especially concentrated in certain organs, such as the renal cortex. We report results obtained during a ten weeks' oral Se supplementation. Experiments were devised to evaluate previous preliminary observations which suggested a possible effect of Se addition on the renal glomerular filtration rate. Eleven healthy volunteers have given increasing oral Se (as a sodium selenite solution) as follows: on the first week they have given 100 micrograms Se per day; this was progressively increased 100 micrograms per day for each of the following 6 weeks; the last dose (700 micrograms per day) was maintained for three further weeks. Serum and 24-hour urine were collected weekly for creatinine determination by kinetic Jaffé reaction and Se measurement by proton-induced X ray emission (PIXE). The final mean serum creatinine concentration was 13% lower than the initial mean value (p less than 0.01). Mean creatinine clearance increased significantly (p less than 0.05) and showed a direct correlation with mean Se clearance (r = 0.79; p less than 0.001). As the increase of creatinine clearance was concomitant with a reduction of serum creatinine levels, we excluded the possibility of toxic effects. Our results seem to suggest a positive influence of Se supplementation on the rate of glomerular filtration and we hypothesize that Se might be involved in the vascular regulatory mechanism of the kidney.

Serum selenium in liver cirrhosis: correlation with markers of fibrosis.

In 55 patients with alcoholic cirrhosis and in 47 healthy individuals we assayed the concentration of selenium in serum (S-Se) by proton induced X-ray emission, the aminoterminal peptide of type III procollagen (NPIIIP) by RIA and the plasma fibronectin (FN) by immuno-nephelometry, together with routine biochemical tests. S-Se was lower in cirrhosis than in controls (0.57, SD 0.20 vs 0.92, SD 0.16 mumol/l; p less than 0.001) and was more reduced in ascitic than in compensated patients (0.50, SD 0.19 vs 0.66, SD 0.17 mumol/l; p less than 0.001). Regression analysis showed a positive correlation of S-Se with serum albumin and FN, whereas necrotic or inflammatory activity seems unrelated to S-Se; a negative correlation was found between S-Se and NPIIIP, suggesting a protective role of selenium against fibrosis.

Erythrocyte antioxidant enzymes and selenium serum levels in an Andean population.

A preliminary study indicated that erythrocyte antioxidant enzyme activities were enhanced in chronic hypoxaemic patients, in whom an increased oxidant stress could be present as a consequence of augmented haemoglobin autoxidation. We have now evaluated the behaviour of erythrocyte antioxidant enzymes and of their related trace metal serum levels in conditions of chronic hypobaric hypoxia in an Andean population living at high altitude (3800 m above sea level), and in a similar ethnic group living at sea level. The results indicate a significant reduction in erythrocyte glutathione peroxidase activity and a low serum level of selenium in the Andean population. Thus, in contrast to what happens in chronic hypoxaemic patients, this group of Andean subjects seems to be poorly protected against oxidant stress, probably as a consequence of selenium deficiency in the diet.

Serum selenium levels in malignant lymphoproliferative diseases.

Serum selenium levels were measured in 38 patients with malignant lymphoproliferative diseases (MLD) and in 34 non-hospitalized healthy individuals. Selenium was determined by proton induced x-ray emission. In Hodgkin's disease and non-Hodgkin malignant lymphoma the mean serum levels of selenium were not different from those of the control group. On the contrary lowered mean serum selenium concentrations were observed in the group with chronic lymphocytic leukaemia (5.2 +/- 0.7 microgram/100 ml) as compared to normal individuals (7.9 +/- 0.3 microgram/100 ml). The difference is highly significant (P less than 0.005). A second selenium test was made in 11 out of the 38 patients within 8 weeks from the beginning of radiotherapy or chemotherapy; unchanged levels were found.

Neonatal erythrocyte glutathione peroxidase deficiency as a consequence of selenium imbalance during pregnancy.

The red blood cell (RBC) glutathione peroxidase (GSH-Px) activity and routine haematological parameters were measured in 38 healthy north Italian full-term pregnant women and in their newborn infants. In 31 pairs the serum selenium concentration was also measured. Data were compared with those of 20 normal adult controls (10 males and 10 females). Newborn infants exhibited significantly lower RBC GSH-Px activity and serum selenium concentrations than adult controls. Pregnant women had serum selenium values intermediate between those of adult female controls and their newborn infants. In both the pregnant women and newborns the RBC GSH-Px activity correlated with the level of selenium in serum which suggests that the neonatal RBC GSH-Px deficiency may be partially due to insufficient availability of selenium during pregancy. Factors other than selenium concentration, e.g. hormonal and genetic, might also affect the RBC GSH-Px activity as suggested by sex differences and mother/child concordances in enzyme activity found in our cases.

Erythrocytic glutathione peroxidase: its relationship to plasma selenium in man.

Erythrocytic glutathione-peroxidase (GSH-Px) activity and plasma selenium concentrations were measured in 14 patients: 7 with iron deficiency and 7 with raised serum iron levels. The decreased enzymatic activity in iron deficiency was confirmed. Plasma selenium was significantly lower in patients with lower serum iron; furthermore there is a significant correlation between serum iron and plasma selenium concentrations. Another correlation even more significant was found between plasma selenium and enzyme activity in all the cases we studied. These data suggests that the importance of iron for GSH-Px activity may be merely due to its relationship with selenium and that plasma selenium concentration may be of critical importance for enzyme activity.