Elizabeth Maria Talá de Souza

Perfil lipídico de quatro espécies de peixes da região pantaneira de Mato Grosso do Sul

Brazilian rivers have a great diversity of fish, however, little is known about the nutritional potential of most native fish. The present study evaluates the centesimal composition and the fatty acid profile of the muscle tissue of four species of fish: pintado (Pseudoplatystoma coruscans), cachara (Pseudoplatystoma fasciatum), pacu (Piaractus mesopotamicus) and dourado (Salminus maxillosus), from the Miranda River in the pantanal region of Mato Grosso do Sul. Dourado had the highest protein content (21.12%), while pintado had the lowest value (17.90%). There was no difference between the protein levels of cachara and pacu (approximately 18%). Pacu fillets were revealed to be the most caloric and this value did not change when the dry sample was considered. The four fish species presented oleic acid (20.25 to 37.25%) as the predominant fatty acid, followed by palmitic acid (19.96 to 21.37%) and stearic acid (7.39 to 9.82%). Total polyunsaturated fatty acid contents varied from 5.24 in pacu to 17.33% in pintado; and total saturated fatty acids from 32.91 to 38.89%. Cachara, pintado and dourado species presented equal proportions of polyunsaturated fatty acids of the ω-3 family (average of 7.80%) and of the ω-6 family (average of 8.40%), while pacu presented the lowest contents of these fatty acids (1.13 and 4.11%, respectively). All the samples studied presented ω6/ω3 and hypocholesterolemic/hypercholesterolemic (HH) indexes that indicate good nutritional quality. Only pacu presented non-recommended levels in relation to trombogenicity (TI) and polyunsaturated/saturated (P/S) indexes.

Purification and partial characterization of a Schizolobium parahyba chymotrypsin inhibitor

Schizolobium parahyba seed chymotrypsin inhibitor (SPC) is a protein with M(r) of 20,000 and four half-cystine residues and no free thiol group. SPC is stable at temperatures up to 75 degrees at pH 7 but gradually loses activity when kept at 95 degrees for 1 hr and total inactivation occurs after 5 hr. Amino acid analysis shows a high content of glycine, aspartate, glutamate and alanine residues. A pI of 4.52 predicted from the amino acid content agrees with experimental results. A stable binary complex with M(r) of 45,000, Ki = 5.85 x 10(-8) M and molar ratio of 1:1 is formed between SPC and chymotrypsin. The determined single N-terminal sequence of SPC shows homology with Kunitz type soybean trypsin inhibitors.

Avaliação bioquímica de vitamina A em escolares de uma comunidade rural

OBJECTIVE: To investigate the prevalence of vitamin A deficiency among schoolchildren from a rural area in the Distrito Federal, Brazil, and to correlate this with rates of anemia and malnutrition. METHODS: From a total of 179 students, the study recruited 155 schoolchildren (5 to 18 years), whose parents gave permission for blood tests. Plasma retinol concentration was assayed by high resolution liquid chromatography, and levels of plasma vitamin A lower than 20 µg/dL were defined as abnormal or deficient in vitamin A. Hemoglobin was measured by an automated cell counter, and anemia was defined as serum concentrations of less than 11.5 and 12.0 g/dL for children and adolescents, respectively. Nutritional status was assessed using z scores for weight/height, height/age and body mass index percentiles. RESULTS: The results indicated that 33.55% of the schoolchildren tested had a vitamin A deficiency, with a prevalence of 35.44% among children (5-9 years) and 31.58% among adolescents (10-18 years). No correlation was observed between the prevalence of vitamin A deficiency and prevalence rates of anemia or malnutrition. Both sexes and all ages were homogeneous for vitamin A deficiency. CONCLUSIONS: The elevated prevalence of vitamin A deficiency among the children and adolescents attending this rural school identify a public health problem in the region. These results indicate that age groups from 5 years onwards should be included in those at risk of hypovitaminosis A and that they should be included in public policies aimed at combating hypovitaminosis A.

Nutritional assessment of institutionalized elderly with different instruments

OBJECTIVE: The objective of this study was to assess the nutritional risk of institutionalized elderly with different nutritional assessment tools. METHODS: This was a cross-sectional study with 37 seniors aged 60 to 100 year living in a long-stay Institution of the Federal District. The assessment included different anthropometric measurements such as body mass index, arm circumference, calf circumference, waist-to-hip ratio and weight gain, total lymphocyte count and administration of the Mini Nutritional Assessment. RESULTS: Arm circumference revealed that 36.1% of the elderly were undernourished, 16.7% were overweight and obese and 47.2% were normal weight. Body mass index revealed 47.9% to be normal weight, a smaller proportion (27.0%) to be underweight and another 27.0% to be overweight. Most of the females (86.4%) and the majority of the males (57.1%) were at risk of cardiovascular diseases according to their waist circumferences. However, when this same risk was assessed by the waist-to-hip ratio, the proportion of females at risk was significantly higher (95.5%). The percentage of the males at risk according to the same parameter was 42.9%. Immunedepletion was found in 46.7% of the males and 66.7% of the females. The nutritional status determined by the Mini Nutritional Assessment showed that 50.0% of the women and 40.0% of the men were at risk of malnutrition. If nutritional risk was determined by having at least one anthropometric indicator below the normal range, most of the elderly (83.8%) were at risk. The Mini Nutritional Assessment showed a similar trend: 75.7% of subjects were at nutritional risk. CONCLUSION: In the institution under study, a significant majority of the elderly of both genders were at nutritional risk according to anthropometric indicators or the Mini Nutritional Assessment.

Regional low-cost diet supplement improves the nutritional status of school children in a semi-arid region of Brazil.

Non-governmental organizations (NGOs) in Brazil have used an alternative diet supplement known as multimixture (MM) composed of bran cereals, cassava leaf powder and eggshell powder. This study investigated the effectiveness of this MM supplement used concomitantly with other actions to improve children’s health. Thirty-one students enrolled in a rural school were examined for anthropometric and hematologic measures before and after the consumption of diet supplemented with MM. The results were compared with those from control group (n = 26) who consumed the same diet without MM. At the end of the study, the NGO intervention provided a beneficial effect on the nutritional status of children, since it improved their blood parameters and reduced the anemia independently of MM supplementation. The average height/age was significantly higher only in the group that received MM. The supplementation of the deficient diets with MM contributed significantly to the improvement of the children’s stature.

Effects of Denaturing and Stabilizing Agents on the Inhibitory Activity and Conformational Stability of Schizolobium parahyba Chymotrypsin Inhibitor

The conformational stability of the Schizolobium parahyba chymotrypsin inhibitor (SPCI) was investigated based on conformational changes and inhibitory activity in the presence of chaotropic and stabilizing agents. At 90°C, the half-lifetime of SPCI was 154 min, while in the presence of 1 M KCl and 20% PEG 20,000, it was drastically reduced to 6 and 3 min, respectively. In contrast, at 90°C, the SPCI structure remained unaltered with the addition of 1 mM DTT and 56% glycerol. The reduction of the two disulfide bonds caused conformational changes in the SPCI without altering the inhibitory activity, suggesting that disulfide bonds are irrelevant to the maintenance of SPCI conformation. Unfolded structures were formed in the presence of 6 M GdnHCl, while in the presence of 8 M urea, destabilization was due to peptide bond rupture. These results suggest that the thermal inactivation of SPCI involves conformational changes and that hydrophobic and electrostatic interactions play a significant role, while the disulfide bonds are of secondary importance in maintaining the high thermal stability of SPCI.

Malanga (Xanthosoma sagittifolium) and Purslane (Portulaca oleracea) Leaves Reduce Oxidative Stress in Vitamin A-Deficient Rats

Aim: This study examined the ability of tropical vegetables to reduce oxidative stress induced by vitamin A deficiency. Methods: Vitamin A-deficient male Wistar rats were divided into four groups which were treated for 30 days with different diets: AIN-93G vitamin A-deficient diet (DD), DD supplemented with pure β-carotene (β-D) and DD supplemented with malanga (Xanthosoma sagittifolium) (MD) or purslane (Portulaca oleracea) (PD) leaves as the only source of vitamin A. The thiobarbituric acid-reactive substances (TBARS), reduced (GSH) and oxidized (GSSG) glutathione, and antioxidant enzyme activities were determined in the heart and liver. Results: The rats fed β-D, MDand PD showed liver and heart TBARS concentrations lower than did DD rats. The liver GSH concentration of β-D, MD and PD rats was lower compared to DD rats. The heart GSSG concentration of the vegetable groups was significantly lower than in DD rats. Liver and heart catalase activities were not significantly different among the groups, nor was heart glutathione peroxidase (GPX) activity, however the β-D rats showed the highest liver GPX activity. There was no difference in liver glutathione-S-transferase level among the groups, while heart activity was higher in rats fed the vegetable leaves. Conclusion: This study evidences that the ingestion of purslane or malanga leaves may have a protective effect against oxidative stress caused by vitamin A deficiency.

Protein improves the bioavailability of calcium and phosphorus from an alternative dietary supplement in rats

Abstract A mixture of bran cereals, cassava leaf and eggshell powder has been used as an alternative diet supplement to fight malnutrition in low-income communities in Brazil. Due to the high phytic acid content there are some concerns about the bioavailability of nutrients in this mixture (MM). This study investigated the effect of dietary concentrations of protein and NaCl on the bioavailability of MM calcium and phosphorus. Undernourished rats were given deficient diet supplemented with MM, with or without the addition of protein and NaCl. Calcium and phosphorus were found to be bioavailable, since rats fed MM supplemented diet showed higher femur calcium and phosphorus contents than did deficient rats (P

Biochemical assessment of vitamin A in schoolchildren from a rural community

OBJECTIVE To investigate the prevalence of vitamin A deficiency among schoolchildren from a rural area in the Distrito Federal, Brazil, and to correlate this with rates of anemia and malnutrition. METHODS From a total of 179 students, the study recruited 155 schoolchildren (5 to 18 years), whose parents gave permission for blood tests. Plasma retinol concentration was assayed by high resolution liquid chromatography, and levels of plasma vitamin A lower than 20 microg/dL were defined as abnormal or deficient in vitamin A. Hemoglobin was measured by an automated cell counter, and anemia was defined as serum concentrations of less than 11.5 and 12.0 g/dL for children and adolescents, respectively. Nutritional status was assessed using z scores for weight/height, height/age and body mass index percentiles. RESULTS The results indicated that 33.55% of the schoolchildren tested had a vitamin A deficiency, with a prevalence of 35.44% among children (5-9 years) and 31.58% among adolescents (10-18 years). No correlation was observed between the prevalence of vitamin A deficiency and prevalence rates of anemia or malnutrition. Both sexes and all ages were homogeneous for vitamin A deficiency. CONCLUSIONS The elevated prevalence of vitamin A deficiency among the children and adolescents attending this rural school identify a public health problem in the region. These results indicate that age groups from 5 years onwards should be included in those at risk of hypovitaminosis A and that they should be included in public policies aimed at combating hypovitaminosis A.

Vibrational spectroscopic analysis of a chymotrypsin inhibitor isolated from Schizolobium parahyba (Vell) Toledo seeds

Abstract Laser Raman and Fourier transform infrared spectroscopies were applied in the investigation of conformational features of a chymotrypsin inhibitor (SPC), inactive on trypsin, isolated from Schizolobium parahyba, a Leguminosae of the Cesalpinoidae family, found in tropical and subtropical regions. As a serine protease inhibitor, its importance is related to the control of proteolytic activity, which in turn is involved in a wide range of critically important biotechnological issues, such as blood coagulation, tumour cell growth, and plant natural defences against predators. SPC is a 20 kDa molecular mass monomeric protein, with two disulfide bonds. Its complete aminoacid primary sequence has not yet been determined. We analysed protein backbone conformation for the lyophylized solid and for an evaporated film, through Raman scattering and FTIR, respectively. The presence of significant amounts of disordered structures and of non-negligible contributions from α -helical and β -sheet structures were reckoned in both cases. The geometries of the disulfide bonds were defined: a gauche - gauche - gauche geometry was verified for one of the two bridges and a transient gauche - gauche - trans / trans - gauche - trans geometry has been indicated for the second one.Two out of the three tyrosine residues were shown to be in external location in the solid protein, as well as the only tryptophan residue.