Age-related effects of DHEA on peripheral markers of oxidative stress

The role for long-term use of dehydroepiandrosterone in adrenal insufficiency

PURPOSE OF REVIEW

Dehydroepiandrosterone (DHEA) is an androgen produced by the zona reticularis of the adrenal gland. Patients with adrenal insufficiency will have a deficiency of DHEA. Unlike glucocorticoid and mineralocorticoid replacement, DHEA supplementation is not considered essential for life and is therefore not routinely replaced in adrenal failure. DHEA deficiency is associated with morbidity, including adverse impacts on metabolic function, quality of life and sexuality in multiple studies. The role for replacement, however, remains unclear.

RECENT FINDINGS

The benefits of DHEA supplementation have been definitively demonstrated in a number of historical studies of patients with primary and secondary adrenal insufficiency. Beneficial impacts on quality of life, body composition, bone health and metabolic markers have been demonstrated. However, published data are inconsistent; controversies persist around the exact role of DHEA replacement and around which patient cohorts are most likely to benefit. There is also a paucity of recent randomized controlled trials in the medical literature to inform on optimal dose and duration of DHEA replacement in adrenal failure.

SUMMARY

Here, we review the evidence for DHEA supplementation in patients with adrenal insufficiency. We highlight knowledge gaps in the medical literature and areas that should be prioritized for future research endeavours.

Oxidative stress, antioxidants, hormesis and calorie restriction: The current perspective in the biology of aging

Aging, in a large measure, has long been defined as the resultant of oxidative stress acting on the cells. The cellular machinery eventually malfunctions at the basic level by the damage from the processes of oxidation and the system starts slowing down because of intrinsic eroding. To understand the initial destruction at the cellular level spreading outward to affect tissues, organs and the organism, the relationship between molecular damage and oxidative stress is required to understand. Retarding the aging process is a matter of cumulatively decreasing the rate of oxidative damage to the cellular machinery. Along with the genetic reasons, the decrease of oxidative stress is somehow a matter of lifestyle and importantly of diet. In the current review, the theories of aging and the understanding of various levels of molecular damage by oxidative stress have been emphasized. A broader understanding of mechanisms of aging have been elaborated in terms of effects of oxidative at molecular, mitochondrial, cellular and organ levels. The antioxidants supplementation, hormesis and calorie restriction as the prominent anti-aging strategies have also been discussed. The relevance and the efficacy of the antiaging strategies at system level have also been presented.

DHEA-pretreatment attenuates oxidative stress in kidney-cortex and liver of diabetic rabbits and delays development of the disease

In view of reported discrepancies concerning antioxidant activity of dehydroepiandrosterone (DHEA), a widely used dietary supplement, the current investigation was undertaken to evaluate the antioxidant properties of DHEA in both kidney-cortex and liver of alloxan (ALX)-induced diabetic rabbits, as this diabetogenic compound exhibits the ROS-dependent action. ALX was injected to animals following 7 days of DHEA administration. Four groups of rabbits were used in the experiments: control, DHEA-treated control, diabetic and DHEA-treated diabetic. Our results show for the first time, that in kidney-cortex DHEA resulted in normalization of hydroxyl free radicals (HFR) levels and restoration of catalase (CAT) and glutathione peroxidase (GPx) activities to near the control values, while in liver DHEA prevented the malondialdehyde (MDA) accumulation and normalized glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PDH) activities. Moreover, in both kidney-cortex and liver DHEA supplementation prevented GSSG elevation accompanied by a decrease in GSH/GSSG ratio. Although DHEA attenuated oxidative stress in both kidney-cortex and liver of ALX-induced diabetic rabbits and significantly delayed the onset of diabetes in time, it did not protect against the final development of diabetes. In conclusion, the current investigation underscores the complexity of the antioxidant action of DHEA. The data are of clinical interest since DHEA supplementation could prevent the deleterious effects of ROS and delay, or even prevent the onset of many diseases. However, in view of the reported pro-oxidant effects of high DHEA doses, the potential use of this agent as a supplement needs a careful evaluation.

Amelioration of oxidative stress-mediated apoptosis in copper oxide nanoparticles-induced liver injury in rats by potent antioxidants

The purpose of this study is to investigate the therapeutic efficacy of individual or combined doses of dehydro-epiandrosterone (DHEA) and quercetin in ameliorating some biochemical indices in liver of CuO-NPs intoxicated-rats. CuO-NPs (50 nm) was administered as a daily oral dose 100 mg/kg for 2 weeks to rats followed by the fore-mentioned antioxidants for 1 month. We highlighted the therapeutic effect of DHEA and quercetin against CuO-NPs toxicity through monitoring the alteration of liver enzyme activity, antioxidant defense mechanism, necrosis, apoptosis, histopathological alterations, and DNA damage. The rats given CuO-NPs only showed marked significant elevation in liver enzymes, alteration in oxidant-antioxidant balance and an elevation in the hepatic inflammatory marker; tumor necrosis factor-α. Additionally, over expression of both caspase-3 and Bax proteins were detected. Whereas, Bcl2 was down regulated and DNA fragmentation was elevated. Moreover, Histopathological examination of hepatic tissue reinforced the previous biochemical results. Co-treatment with either DHEA, quercetin alone or in combination ameliorated the deviated parameters with variable degrees against CuO-NPs toxicity in rat. In conclusion, our findings suggested that the aforementioned treatments exert therapeutic effect in CuO-NPs toxicity by diminishing oxidative stress, mRNA gene expression and hepatic tissues DNA damage.

A pilot study comparing the metabolic profiles of elite-level athletes from different sporting disciplines

Background

The outstanding performance of an elite athlete might be associated with changes in their blood metabolic profile. The aims of this study were to compare the blood metabolic profiles between moderate- and high-power and endurance elite athletes and to identify the potential metabolic pathways underlying these differences.

Methods

Metabolic profiling of serum samples from 191 elite athletes from different sports disciplines (121 high- and 70 moderate-endurance athletes, including 44 high- and 144 moderate-power athletes), who participated in national or international sports events and tested negative for doping abuse at anti-doping laboratories, was performed using non-targeted metabolomics-based mass spectroscopy combined with ultrahigh-performance liquid chromatography. Multivariate analysis was conducted using orthogonal partial least squares discriminant analysis. Differences in metabolic levels between high- and moderate-power and endurance sports were assessed by univariate linear models.

Results

Out of 743 analyzed metabolites, gamma-glutamyl amino acids were significantly reduced in both high-power and high-endurance athletes compared to moderate counterparts, indicating active glutathione cycle. High-endurance athletes exhibited significant increases in the levels of several sex hormone steroids involved in testosterone and progesterone synthesis, but decreases in diacylglycerols and ecosanoids. High-power athletes had increased levels of phospholipids and xanthine metabolites compared to moderate-power counterparts.

Conclusions

This pilot data provides evidence that high-power and high-endurance athletes exhibit a distinct metabolic profile that reflects steroid biosynthesis, fatty acid metabolism, oxidative stress, and energy-related metabolites. Replication studies are warranted to confirm differences in the metabolic profiles associated with athletes’ elite performance in independent data sets, aiming ultimately for deeper understanding of the underlying biochemical processes that could be utilized as biomarkers with potential therapeutic implications.

Electronic supplementary material

The online version of this article (10.1186/s40798-017-0114-z) contains supplementary material, which is available to authorized users.

DHEA supplementation to dexamethasone-treated rabbits alleviates oxidative stress in kidney-cortex and attenuates albuminuria

Our recent study has shown that dehydroepiandrosterone (DHEA) administered to rabbits partially ameliorated several dexamethasone (dexP) effects on hepatic and renal gluconeogenesis, insulin resistance and plasma lipid disorders. In the current investigation, we present the data on DHEA protective action against dexP-induced oxidative stress and albuminuria in rabbits. Four groups of adult male rabbits were used in the in vivo experiment: (1) control, (2) dexP-treated, (3) DHEA-treated and (4) both dexP- and DHEA-treated. Administration of dexP resulted in accelerated generation of renal hydroxyl free radicals (HFR) and malondialdehyde (MDA), accompanied by diminished superoxide dismutase (SOD) and catalase activities and a dramatic rise in urinary albumin/creatinine ratio. Treatment with DHEA markedly reduced dexP-induced oxidative stress in kidney-cortex due to a decline in NADPH oxidase activity and enhancement of catalase activity. Moreover, DHEA effectively attenuated dexP-evoked albuminuria. Surprisingly, dexP-treated rabbits exhibited elevation of GSH/GSSG ratio, accompanied by a decrease in glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities as well as an increase in glucose-6-phosphate dehydrogenase (G6PDH) activity. Treatment with DHEA resulted in a decline in GSH/GSSG ratio and glutathione reductase (GR) activity, accompanied by an elevation of GPx activity. Interestingly, rabbits treated with both dexP and DHEA remained the control values of GSH/GSSG ratio. As the co-administration of DHEA with dexP resulted in (i) reduction of oxidative stress in kidney-cortex, (ii) attenuation of albuminuria and (iii) normalization of glutathione redox state, DHEA might limit several undesirable renal side effects during chronic GC treatment of patients suffering from allergies, asthma, rheumatoid arthritis and lupus. Moreover, its supplementation might be particularly beneficial for the therapy of patients with glucocorticoid-induced diabetes.

Protective effect of DHEA on hydrogen peroxide-induced oxidative damage and apoptosis in primary rat Leydig cells

Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement due to its putative anti-aging properties. However, the effect of DHEA in Leydig cells, a major target cell of DHEA biotransformation in male, are not clear. The present study aimed to investigate the preventative effect of DHEA on oxidative damage and apoptosis after H₂O₂ treatment in Leydig cells. The results showed that DHEA treatment attenuated the reduction of cell viability induced by H₂O₂. No differences were observed on the superoxide anion (O₂^-) content, while DHEA treatment decreased reactive oxygen species (ROS) and hydroxyl radical (OH) content in H₂O₂-treated Leydig cells. Pre-treatment with DHEA increased peroxidase (POD) activity and decreased glutathione peroxidase (GSH-Px) activity in H₂O₂-treated Leydig cell. DHEA treatment attenuated DNA damage as indicated by the decreasing of tail moment, comet length and olive tail moment. Total apoptosis ratio and early apoptosis ratio were significantly decreased in H₂O₂-treated Leydig cell that were pre-treatment with DHEA. DHEA treatment decreased Bax, capase-9 and capase-3 mRNA levels in H₂O₂-treated Leydig cells. Our results demonstrated that pre-treatment with DHEA prevented the Leydig cells oxidative damage caused by H₂O₂ through increasing POD activity, which resulted in inhibition of OH generation. Meanwhile, pre-treatment with DHEA inhibited H₂O₂-induced Leydig cells early apoptosis which mainly by reducing the pro-apoptotic protein Bax and caspases-9, caspases-3 mRNA levels. This information is important to understand the molecular mechanism of anti-ageing effect and potential application in treatment of oxidative stress induced related diseases of DHEA.

Association between dehydroepiandrosterone-sulfate and attention in long-term survivors of childhood acute lymphoblastic leukemia treated with only chemotherapy

Long-term survivors of childhood acute lymphoblastic leukemia (ALL) are at risk for neurocognitive impairment, as well as compromised hypothalamic-pituitary-adrenal (HPA) function. Dehydroepiandrosterone-sulfate (DHEAS) is an adrenal androgen commonly used as a marker of HPA function. In the general population, a low level of DHEAS has been associated with poorer cognition. At ≥2years post-treatment, we examined the association of DHEAS with attention outcomes in 35 male and 34 female long-term survivors of childhood ALL (mean[standard deviation] age at evaluation 14.5[4.7] years; 7.5[1.9] years post-diagnosis) who were treated with only chemotherapy and without prophylactic cranial irradiation. Male survivors with low-normal levels of DHEAS had worse performance than male survivors with high levels of DHEAS on multiple measures of attention (all P's<0.05). However, association between DHEAS and attention measures were not found in female survivors. Our results suggest that survivors of ALL who suffer from partial but persistent adrenal insufficiency may be at risk for neurocognitive deficits. This finding should be validated in a larger prospective study, with attention to sex differences in the potential impact of adrenal insufficiency on neurocognitive outcomes.

Sirtuin 1 protects the aging heart from contractile dysfunction mediated through the inhibition of endoplasmic reticulum stress-mediated apoptosis in cardiac-specific Sirtuin 1 knockout mouse model

BACKGROUND

The longevity regulator Sirtuin 1 is an NAD⁺-dependent histone deacetylase that regulates endoplasmic reticulum stress and influences cardiomyocyte apoptosis during cardiac contractile dysfunction induced by aging. The mechanism underlying Sirtuin 1 function in cardiac contractile dysfunction related to aging has not been completely elucidated.

METHODS

We evaluated cardiac contractile function, endoplasmic reticulum stress, apoptosis, and oxidative stress in 6- and 12month-old cardiac-specific Sirtuin 1 knockout (Sirt1^-/-) and control (Sirt1^f/f) mice using western blotting and immunohistochemistry. Mice were injected with a protein disulphide isomerase inhibitor. For in vitro analysis, cultured H9c2 cardiomyocytes were exposed to either a Sirtuin 1 inhibitor or activator, with or without a mitochondrial inhibitor, to evaluate the effects of Sirtuin 1 on endoplasmic reticulum stress, nitric oxide synthase expression, and apoptosis. The effects of protein disulphide isomerase inhibition on oxidative stress and ER stress-related apoptosis were also investigated.

RESULTS

Compared with 6-month-old Sirt1^f/f mice, marked impaired contractility was observed in 12-month-old Sirt1^-/- mice. These findings were consistent with increased endoplasmic reticulum stress and apoptosis in the myocardium. Measures of oxidative stress and nitric oxide synthase expression were significantly higher in Sirt1^-/- mice compared with those in Sirt1^f/f mice at 6months. In vitro experiments revealed increased endoplasmic reticulum stress-mediated apoptosis in H9c2 cardiomyocytes treated with a Sirtuin 1 inhibitor; the effects were ameliorated by a Sirtuin 1 activator. Moreover, consistent with the in vitro findings, impaired cardiac contractility was demonstrated in Sirt1^-/- mice injected with a protein disulphide isomerase inhibitor.

CONCLUSION

The present study demonstrates that the aging heart is characterized by contractile dysfunction associated with increased oxidative stress and endoplasmic reticulum stress and Sirtuin 1 might have the ability to protect the aging hearts from the inhibition of endoplasmic reticulum-mediated apoptosis.

Dehydroepiandrosterone ameliorates H2O2-induced Leydig cells oxidation damage and apoptosis through inhibition of ROS production and activation of PI3K/Akt pathways

Dehydroepiandrosterone (DHEA) is widely used as a nutritional supplement, and administration of DHEA produces a number of beneficial effects in the elderly. Many researchers have suggested that DHEA exerts it function after conversion into more biologically active hormones in peripheral target cells. The actions of DHEA in Leydig cells, a major target cell of DHEA biotransformation in males, are not clear. The present study found that DHEA increased cell viability and decreased reactive oxygen species (ROS) and malondialdehyde contents in H2O2-induced Leydig cells. DHEA significantly increased the activities of superoxide dismutase, catalase and peroxidase, and decreased the DNA damage in H2O2-induced Leydig cells. Apoptosis was significant decreased in H2O2-induced Leydig cells after DHEA treatment. DHEA inhibited the loss of mitochondrial membrane potential (ΔΨm) and the upregulation of the caspase-3 protein level induced by H2O2 in Leydig cells. DHEA also reversed the decrease in PI3K and p-Akt protein levels induced by H2O2. These data showed that DHEA could ameliorate H2O2-induced oxidative damage by increasing anti-oxidative enzyme activities, which resulted in reduced ROS content, and decreased apoptosis, mainly by preventing the loss of ΔΨm and inhibiting caspase-3 protein levels via activation of PI3K/Akt signaling pathways. These results increase our understanding of the molecular mechanism of the anti-ageing effect of DHEA.

Age-related changes of myocardial ATP supply and demand mechanisms

In advanced age, the resting myocardial oxygen consumption rate (MVO2) and cardiac work (CW) in the rat remain intact. However, MVO2, CW and cardiac efficiency achieved at high demand are decreased with age, compared to maximal values in the young. Whether this deterioration is due to decrease in myocardial ATP demand, ATP supply, or the control mechanisms that match them remains controversial. Here we discuss evolving perspectives of age-related changes of myocardial ATP supply and demand mechanisms, and critique experimental models used to investigate aging. Specifically, we evaluate experimental data collected at the level of isolated mitochondria, tissue, or organism, and discuss how mitochondrial energetic mechanisms change in advanced age, both at basal and high energy-demand levels.

Aging might augment reactive oxygen species (ROS) formation and affect reactive nitrogen species (RNS) level after myocardial ischemia/reperfusion in both humans and rats

Previous studies indicate aging results in significantly decreased cardiac function and increased myocardial apoptosis after myocardial ischemia/reperfusion (MI/R) in humans or rats. The underlying mechanisms of aging-exacerbated effects remain unknown. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are known to play vital roles in aging-related MI/R injury. Heretofore, the effects of aging upon ROS and RNS formation were not investigated in humans, which is the focus of the current study. Due to experimental limitations with clinical trials, an additional animal experiment was performed. All enrolled acute myocardial infarction (AMI) patients received percutaneous coronary intervention (PCI) therapy. AMI patients were assigned into two groups: adult (age <65, n = 34) and elderly (age ≥65, n = 45) AMI patients. Blood samples were obtained from all study participants at 24 h and 3 days post-PCI. Plasma/white blood cell (WBC) ROS and RNS markers (malondialdehyde (MDA), myeloperoxidase (MPO), reduced glutathione (GSH), inducible nitric oxide synthase (iNOS) activity, NOx, and nitrotyrosine) were determined. The same markers were determined in rat cardiac tissue after 24 h MI/R. Compared to the adult group, elderly patients manifested increased plasma MDA and MPO and decreased plasma GSH concentrations. No significant differences in plasma NOx or nitrotyrosine concentration existed between adult and elderly patients. Furthermore, WBC iNOS activity in elderly patients was significantly decreased compared to the adult group. The measurement of ROS markers in the rat experiments was consistent and supported human study data. Surprisingly, RNS markers (NOx and nitrotyrosine) in blood and heart tissue increased from young to middle-aged rats but decreased from middle age to old age. Aging augments ROS, which might exacerbate MI/R injury. Additionally, our data support aging-induced changes of RNS levels in humans and rats in vivo.

Impact of trace element changes on dehydroepiandrosterone sulfate in healthy and diabetic states among middle-age and elderly Egyptians

The aim of this study was to confirm if there is a link between the alteration in blood levels of trace elements (chromium, copper, lead, cadmium, and zinc) and dehydroepiandrosterone sulfate (DHEAS) in healthy and diabetic states. This study is the first study to test these parameters in Egyptians. The study included 150 subjects divided into the following four groups: healthy middle-aged, healthy elderly, middle-aged diabetics, and elderly diabetics. Our results revealed a statistically significant decrease in the level of DHEAS in the elderly compared to middle-aged healthy and diabetic groups (p < 0.05). There was a significant difference between the middle-aged groups with respect to zinc, copper, chromium, and cadmium levels. Zinc and copper were lower in the diabetic subjects while chromium and cadmium were higher in the same group in comparison to healthy subjects. In the elderly groups, there were significant increases in chromium and cadmium levels in diabetic subjects rather than healthy ones. There was a significant increase in the thiobarbituric acid reactive substance level in the elderly healthy and diabetic groups and a significant decrease in the glutathione level in the elderly groups. There was no correlation between the levels of trace elements and DHEAS or between the levels of DHEAS, oxidants, and antioxidants in all of the tested groups. In conclusion, only the DHEAS level was correlated with age. There was no difference between the diabetic and healthy groups with respect to the levels of trace elements, with the exception of chromium and cadmium, which suggests the effect of pollution on the pathogenesis of diabetes in Egyptians. No correlation existed between the levels of DHEAS and trace elements, oxidants, and antioxidants. Finally, we believe that there is a large regional variation in the levels of trace elements due to different environmental exposure and nutritional factors which are responsible for contradictory results regarding the pathogenesis of diseases related to alterations in the levels of trace elements.

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.

The role of androgens in follicle maturation and ovulation induction: friend or foe of infertility treatment?

BACKGROUND

Effects of androgens on follicle maturation have been controversial for some time. Here, we review the potential of their applications in improving human ovulation induction, based on human and animal data, reported in the literature.

METHODS

We reviewed the published literature for the years 2005-2011, using relevant key words, in PubMed, Medline and Cochrane reviews, and then performed secondary reviews of referenced articles, which previously had not been known or preceded the searched time period. A total of 217 publications were reviewed.

RESULTS

Contrary to widely held opinion, recent data, mostly developed in the mouse, convincingly demonstrate essential contribution of androgens to normal follicle maturation and, therefore, female fertility. Androgens appear most engaged at preantral and antral stages, primarily affect granulosa cells, and exert effects via androgen receptors (AR) through transcriptional regulation but also in non-genomic ways, with ligand-activated AR modulating follicle stimulating hormone (FSH) activity in granulosa cells. While some androgens, like testosterone (T) and dehydroepiandrosterone (DHEA), appear effective in improving functional ovarian reserve (FOR) in women with diminished ovarian reserve (DOR), others may even exert opposite effects. Such differences in androgens may, at least partially, reflect different levels of agonism to AR.

DISCUSSION

Selective androgens appear capable of improving early stages of folliculogenesis. They, therefore, may represent forerunners of a completely new class of ovulation-inducing medications, which, in contrast to gonadotropins, affect follicle maturation at much earlier stages.

Dehydroepiandrosterone (DHEA) reduces embryo aneuploidy: direct evidence from preimplantation genetic screening (PGS)

BACKGROUND

Dehydroepiandrosterone (DHEA) has been reported to improve pregnancy chances in women with diminished ovarian reserve (DOR), and to reduce miscarriage rates by 50-80%. Such an effect is mathematically inconceivable without beneficial effects on embryo ploidy. This study, therefore, assesses effects of DHEA on embryo aneuploidy.

METHODS

In a 1:2, matched case control study 22 consecutive women with DOR, supplemented with DHEA, underwent preimplantation genetic screening (PGS) of embryos during in vitro fertilization (IVF) cycles. Each was matched by patient age and time period of IVF with two control IVF cycles without DHEA supplementation (n = 44). PGS was performed for chromosomes X, Y, 13, 16, 18, 21 and 22, and involved determination of numbers and percentages of aneuploid embryos.

RESULTS

DHEA supplementation to a significant degree reduced number (P = 0.029) and percentages (P < 0.001) of aneuploid embryos, adjusted for relevant covariates. Short term supplementation (4-12 weeks) resulted in greatest reduction in aneuploidy (21.6%, 95% CI -2.871-46.031).

DISCUSSION

Beneficial DHEA effects on DOR patients, at least partially, are the likely consequence of lower embryo aneuploidy. DHEA supplementation also deserves investigation in older fertile women, attempting to conceive, where a similar effect, potentially, could positively affect public health.