Javier Díaz-Castro

Influence of cow or goat milk consumption on antioxidant defence and lipid peroxidation during chronic iron repletion

Despite Fe deficiency and overload having been widely studied, no studies are available about the influence of milk consumption on antioxidant defence and lipid peroxidation during the course of these highly prevalent cases. The objective of the present study was to assess the influence of cow or goat milk-based diets, either with normal or Fe-overload, on antioxidant defence and lipid peroxidation in the liver, brain and erythrocytes of control and anaemic rats after chronic Fe repletion. Weanling male rats were randomly divided into two groups: a control group receiving a normal-Fe diet (45 mg/kg) and an anaemic group receiving a low-Fe diet (5 mg/kg) for 40 d. Control and anaemic rats were fed goat or cow milk-based diets, either with normal Fe or Fe-overload (450 mg/kg), for 30 or 50 d. Fe-deficiency anaemia did not have any effect on antioxidant enzymes or lipid peroxidation in the organs studied. During chronic Fe repletion, superoxide dismutase (SOD) activity was higher in the group of animals fed the cow milk diet compared with the group consuming goat milk. The slight modification of catalase and glutathione peroxidise activities in animals fed the cow milk-based diet reveals that these enzymes are unable to neutralise and scavenge the high generation of free radicals produced. The animals fed the cow milk diet showed higher rates of lipid peroxidation compared with those receiving the goat milk diet, which directly correlated with the increase in SOD activity. It was concluded that goat milk has positive effects on antioxidant defence, even in a situation of Fe overload, limiting lipid peroxidation.

Melatonin supplementation ameliorates oxidative stress and inflammatory signaling induced by strenuous exercise in adult human males.

Abstract:  Strenuous exercise induces inflammatory reactions together with high production of free radicals and subsequent muscle damage. This study was designed to investigate for the first time and simultaneously whether over‐expression of inflammatory mediators, oxidative stress, and alterations in biochemical parameters induced by acute exercise could be prevented by melatonin. This indoleamine is a potent, endogenously produced free radical scavenger and a broad‐spectrum antioxidant; consequently, it might have positive effects on the recovery following an exercise session. The participants were classified into two groups: melatonin‐treated men (MG) and placebo‐treated individuals (controls group, CG). The physical test consisted in a constant run that combined several degrees of high effort (mountain run and ultra‐endurance). The total distance of the run was 50 km with almost 2800 m of ramp in permanent climbing and very changeable climatic conditions. Exercise was associated with a significant increase in TNF‐α, IL‐6, IL‐1ra (in blood), and also an increase in 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) and isoprostane levels (in urine), and indicated the degree of oxidative stress and inflammation induced. Oral supplementation of melatonin during high‐intensity exercise proved efficient in reducing the degree of oxidative stress (lower levels of lipid peroxidation, with a significant increase in antioxidative enzyme activities); this would lead to the maintenance of the cellular integrity and reduce secondary tissue damage. Data obtained also indicate that melatonin has potent protective effects, by preventing over‐expression of pro‐inflammatory mediators and inhibiting the effects of several pro‐inflammatory cytokines. In summary, melatonin supplementation before strenuous exercise reduced muscle damage through modulation of oxidative stress and inflammation signaling associated with this physical challenge.

Influence of nutritional iron deficiency anemia on DNA stability and lipid peroxidation in rats

OBJECTIVE Oxidative stress results from an imbalance between the formation and neutralization of pro-oxidants. Disturbance of the pro-oxidant/antioxidant balance is also considered to be a causative factor underlying oxidative damage to cellular molecules, such as DNA, causing strand breaks. There is considerable controversy about the antioxidant status in iron-deficiency anemia (IDA), but scant information is available regarding DNA integrity. In the present study, we investigated the relation between DNA stability and hepatic antioxidant capacity in rats with induced IDA. METHODS Peripheral DNA damage was assessed using an alkaline comet assay. Further, the hepatic antioxidant enzyme glutathione peroxidase and the production of thiobarbituric acid-reactive substances were measured in control rats and in those with induced IDA. RESULTS Comparison of the control and anemic rats showed no differences in thiobarbituric acid-reactive substances production in the cytosolic fraction of hepatic cells. Nor were there any differences in liver glutathione peroxidase enzyme activity or DNA stability, as demonstrated by the percentage of DNA in the head (90.77 in control rats versus 88.23 in anemic rats), tail (9.23 in control rats versus 11.76 in anemic rats), and olive tail moment (0.155 in control rats versus 0.141 in anemic rats). CONCLUSION IDA does not affect DNA stability or lipid peroxidation in rats, suggesting that there is enough compensatory capacity to keep antioxidant defenses high.

BMPER Protein Is a Negative Regulator of Hepcidin and Is Up-regulated in Hypotransferrinemic Mice

Background: The mechanism by which anemia results in lowered hepcidin levels is not clear. Results: Bone morphogenetic protein (BMP)-binding endothelial cell precursor-derived regulator (BMPER), a known BMP antagonist, was found to be up-regulated in anemic Trfhpx/hpx mice and to suppress hepcidin transcription both in vivo and in vitro. Conclusion: BMPER is involved in suppressing hepcidin levels in Trfhpx/hpx mice. Significance: BMPER is a novel regulator of hepcidin and iron metabolism. The BMP/SMAD4 pathway has major effects on liver hepcidin levels. Bone morphogenetic protein-binding endothelial cell precursor-derived regulator (Bmper), a known regulator of BMP signaling, was found to be overexpressed at the mRNA and protein levels in liver of genetically hypotransferrinemic mice (Trfhpx/hpx). Soluble BMPER peptide inhibited BMP2- and BMP6-dependent hepcidin promoter activity in both HepG2 and HuH7 cells. These effects correlated with reduced cellular levels of pSMAD1/5/8. Addition of BMPER peptide to primary human hepatocytes abolished the BMP2-dependent increase in hepcidin mRNA, whereas injection of Bmper peptide into mice resulted in reduced liver hepcidin and increased serum iron levels. Thus Bmper may play an important role in suppressing hepcidin production in hypotransferrinemic mice.

A New Insight to Bone Turnover: Role of -3 Polyunsaturated Fatty Acids

Background. Evidence has shown that long-chain polyunsaturated fatty acids (LCPUFA), especially the ω-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial for bone health and turnover. Objectives. This review summarizes findings from both in vivo and in vitro studies and the effects of LC PUFA on bone metabolism, as well as the relationship with the oxidative stress, the inflammatory process, and obesity. Results. Some studies in humans indicate that LCPUFA can increase bone formation, affect peak bone mass in adolescents, and reduce bone loss. However, the cellular mechanisms of action of the LCPUFA are complex and involve modulation of fatty acid metabolites such as prostaglandins, resolvins and protectins, several signaling pathways, cytokines, and growth factors, although in certain aspects there is still some controversy. LCPUFA affect receptor activator of nuclear factor κ β (RANK), a receptor found on the osteoclast, causing bone resorption, which controls osteoclast formation. Conclusions. Since fatty acids are an endogenous source of reactive oxygen species, free radicals alter the process of bone turnover; however, although there are clinical evidences linking bone metabolism and dietary lipids, more clinical trials are necessary to prove whether ω-3 PUFA supplementation plays a major role in bone health.

Goat milk during iron repletion improves bone turnover impaired by severe iron deficiency

The effect of goat or cow milk-based diets, with either normal Fe content or an Fe overload, on bone turnover and the mineralization process was studied in control and anemic rats during chronic Fe repletion. One hundred eighty male Wistar rats were studied during a pre-experimental period of 40 d in which they were randomly divided into 2 groups, a control group receiving the AIN-93G diet with normal Fe content (45 mg/kg of diet) and the Fe-deficient group receiving the AIN-93G diet with low Fe content (5mg/kg of diet) for 40 d. After the pre-experimental period, the rats were fed for 10, 30, or 50 d with goat or cow milk-based diets with a normal Fe content (45 mg/kg of diet) or an Fe overload (450 mg/kg of diet). In anemic rats, goat milk with normal Fe content increased levels of the biomarker of bone formation N-terminal propeptides of type I procollagen and diminished parathyroid hormone levels after only 10 d of supplying this diet, indicating the beginning of restoration of the bone demineralization induced by the anemia, which was not observed with cow milk. After 30 d of supplying the milk-based diets with normal Fe content or an Fe overload, biomarkers of bone formation and bone resorption were not different between control and anemic rats, indicating that the bone demineralization induced by the Fe-deficiency anemia had recovered, although the process of stabilization of bone turnover began earlier in the animals fed goat milk. In addition, a higher Ca deposit was observed in femur, which positively affects bone mineralization, as well as an increase of Fe in sternum, which indicates that the hematopoietic process essentially recovered earlier on the goat milk diet compared with the cow milk diet.

A New Approach to Oxidative Stress and Inflammatory Signaling during Labour in Healthy Mothers and Neonates

The objective of the current study was to investigate for the first time and simultaneously the oxidative stress and inflammatory signaling induced during the delivery in healthy mothers and their neonates. 56 mothers with normal gestational course and spontaneous delivery were selected. Blood samples were taken from mother (before and after delivery) both from vein and artery of umbilical cord. Lower antioxidant enzymes activities were observed in neonates compared with their mothers and lower oxidative stress in umbilical cord artery with respect to vein. There was an overexpression of inflammatory cytokines in the mother, such as IL-6 and TNF-α, and, in addition, PGE2 was also increased. Neonates showed lower levels of IL-6 and TNF-α and higher values of sTNF-RII and PGE2 in comparison with their mothers. Parturition increases oxidative damage in the mother, although the indicators of oxidative damage were lower in umbilical cord artery with respect to umbilical vein. The overexpression of inflammatory cytokines reveals that fetus suffers its own inflammatory process during parturition.

The Timing of Cord Clamping and Oxidative Stress in Term Newborns

BACKGROUND: Clamping and cutting of the umbilical cord is the most prevalent of all operations, but the optimal timing of cord clamping is controversial, with different timings offering advantages and disadvantages. This study, for the first time, compares the influence of early and late cord clamping in correlation with oxidative stress and inflammation signaling, Because cord clamping timing may have a significant influence on placenta-to-infant blood transfer, thereby modifying oxygenation of maternal and fetal tissues, and on the transfer of inflammatory mediators throughout the placenta. METHODS: Sixty-four pregnant subjects were selected at the Gynecology and Obstetrics Services Department of the Clinico San Cecilio Hospital, Granada, Spain, based on disease-free women who experienced a normal course of pregnancy and a spontaneous, vaginal, single delivery. Half of the subjects had deliveries with early-clamped newborn infants (at 10 s), and the other half had late-clamped deliveries (at 2 min). RESULTS: Erythrocyte catalase activity was significantly greater in the late-clamped group than in the early-clamped group (P < .01 for the umbilical vein and P < .001 for the artery). The values for superoxide dismutase, total antioxidant status, and soluble tumor necrosis factor receptor II were all significantly higher in the late-clamped group compared with the early-clamped group (P < .01, P < .001, and P < .001, respectively). CONCLUSIONS: The results suggest a beneficial effect of late cord clamping, produced by an increase in antioxidant capacity and moderation of the inflammatory-mediated effects induced during delivery of term neonates.

Gender specific differences in oxidative stress and inflammatory signaling in healthy term neonates and their mothers

Background:Gender is a crucial determinant of life span, but little is known about gender differences in free radical homeostasis and inflammatory signaling. The aim of the study was to determine gender-related differences concerning oxidative stress and inflammatory signaling of healthy neonates and mothers.Methods:Fifty-six mothers with normal gestational course and spontaneous delivery were selected. Blood samples were collected from the mother (at the beginning of delivery and start of expulsive period) and from neonate (from umbilical cord vein and artery).Results:The mothers of girls featured a higher total antioxidant status and lower plasma hydroperoxides than the mother of boys. Regarding the neonates, the girls featured a higher total antioxidant status and lower plasma membrane hydroperoxides in umbilical cord artery together with higher catalase, glutathione peroxidase, and superoxide dismutase activities. Lower levels of interleukin 6, tumor necrosis factor alpha, and prostaglandin E2 were observed in the mothers of girls and higher level of soluble tumor necrosis factor receptor II. In the neonates, lower levels of interleukin 6 and tumor necrosis factor alpha were observed in umbilical artery and higher soluble tumor necrosis factor receptor II in umbilical cord vein and artery of girls.Conclusion:An association between gender, oxidative stress, and inflammation signaling exists, leading to a renewed interest in the neonate’s sex as a potential risk factor to several alterations.

Calcium-enriched goats' milk aids recovery of iron status better than calcium-enriched cows' milk, in rats with nutritional ferropenic anaemia.

Ca-Fe interactions are known, but no studies are available about the effects of Ca-enriched goat or cow milk on Fe status in nutritional ferropenic anaemia (NFA). To examine this matter, control and Fe-deficient rats were fed for 14 d with goat or cow milk diets containing either normal or high Ca content (5000 or 10,000 mg/kg diet), and different indices and parameters related to iron status were measured. The apparent digestibility coefficient (ADC) and the Fe retention/intake (R/I) ratio were higher in control and anaemic rats fed goat milk diet (G diet), despite high-Ca content. Ca enrichment decreased Fe stores in liver and sternum in anaemic rats fed cow milk diet (C diet), however G diet did not modify Fe content in the organs studied in control and anaemic rats. In anaemic rats, Ca-supplementation decreased haematocrit, but platelets and serum Fe were not affected, however, in control rats platelets increased except for Ca-enriched G diet, this fact reveals that Ca-Fe interaction is minimized with G diet. Serum ferritin was always higher in rats fed G vs. C diet, both in control and anaemic rats fed either normal or Ca-enriched diets. Ca-supplementation decreased ferritin levels in control and anaemic rats fed C diet and also, though to a lesser extent, in those given the G diet. This indicates that with this G diet there is a better recovery of body Fe stores in anaemic rats, despite Ca-supplementation. In this study it is noteworthy that despite high Ca content, a goat milk diet resulted in minimal Ca-Fe interactions and did not adversely affect Fe status in rats with NFA.