Administration of estradiol and progesterone modulate the activities of antioxidant enzyme and aminotransferases in naturally menopausal rats

Hormonal Agents for the Treatment of Depression Associated with the Menopause

Perimenopause marks the transition from a woman’s reproductive stage to menopause. Usually occurring between 42 and 52 years of age, it is determined clinically by the onset of irregular menstrual cycles or variable cycle lengths. Women are at an increased risk of depression and anxiety during perimenopause and the menopausal transition. Depressive symptoms experienced in perimenopause are often more severe compared to pre- and post-menopause. During menopausal transition, the impact of fluctuating estrogen in the central nervous system (CNS) can have negative psychological effects for some women. Traditional first-line management of menopausal depression involves antidepressants, with modest outcomes. The positive effects of estrogen treatment in the CNS are becoming increasingly recognised, and hormonal therapy (HT) with estrogen may have a role in the treatment of menopausal depression. In this review we will outline the prevalence, impact and neurochemical basis of menopausal-associated depression, as well as hormone-based approaches that have increasing promise as effective treatments.

Panax Ginseng alleviates thioacetamide-induced liver injury in ovariectomized rats: Crosstalk between inflammation and oxidative stress

Liver diseases impose a substantial health problem. Female hormones play a crucial role in the protection against chronic inflammatory diseases. Fifty female rats were allocated into five groups (n = 10). Group I comprised sham-operated rats. The remaining groups underwent ovariectomy at the beginning of the experiment. Group II served as the ovariectomy-control group. Groups III, IV & V received thioacetamide (TAA; 300 mg/kg; i.p.) to induce liver injury 6 weeks after ovariectomy. Group III served as the TAA-control group. Groups IV & V received panax ginseng (100 and 300 mg/kg/day, p.o.) for 6 weeks post TAA administration. All groups were investigated for liver function tests along with total antioxidant capacity (TAC), tumor necrosis factor-α (TNF-α) and advanced glycation end products (AGEs). Histopathological examination of liver tissues was performed followed by immunohistochemical staining for nuclear factor kappa-B (NF-kβ p65) and myeloperoxidase (MPO). Ovariectomized-rats showed a non-significant change in the measured parameters while TAA administration resulted in significant liver damage. Panax ginseng at both dose levels significantly improved the serum liver function tests and TAC along with decreasing the AGEs and TNF-α. It also restored the histopathological picture of liver tissue and decreased hepatic tissue inflammation via reduction of MPO and NF-kβ p65 immunoreactivity. The current study is the first to elucidate the effect of panax ginseng against TAA-induced liver injury in ovariectomized rats which mimic aged post-menopausal estrogen-deficient females. The study demonstrates the crosstalk between AGEs, NF-kβ and MPO in the modulation of inflammation. Panax ginseng possesses antioxidant and anti-inflammatory properties.

Stress and Loss of Ovarian Function: Novel Insights into the Origins of Sex-Based Differences in the Manifestations of Respiratory Control Disorders During Sleep

The respiratory system of women and men develops and functions in distinct neuroendocrine milieus. Despite differences in anatomy and neural control, homeostasis of arterial blood gases is ensured in healthy individuals regardless of sex. This convergence in function differs from the sex-based differences observed in many respiratory diseases. Sleep-disordered breathing (SDB) results mainly from episodes of upper airway closure. This complex and multifactorial respiratory disorder shows significant sexual dimorphism in its clinical manifestations and comorbidities. Guided by recent progress from basic research, this review discusses the hypothesis that stress is necessary to reveal the sexual dimorphism of SDB.

Revisiting Traumatic Brain Injury: From Molecular Mechanisms to Therapeutic Interventions

Studying the complex molecular mechanisms involved in traumatic brain injury (TBI) is crucial for developing new therapies for TBI. Current treatments for TBI are primarily focused on patient stabilization and symptom mitigation. However, the field lacks defined therapies to prevent cell death, oxidative stress, and inflammatory cascades which lead to chronic pathology. Little can be done to treat the mechanical damage that occurs during the primary insult of a TBI; however, secondary injury mechanisms, such as inflammation, blood-brain barrier (BBB) breakdown, edema formation, excitotoxicity, oxidative stress, and cell death, can be targeted by therapeutic interventions. Elucidating the many mechanisms underlying secondary injury and studying targets of neuroprotective therapeutic agents is critical for developing new treatments. Therefore, we present a review on the molecular events following TBI from inflammation to programmed cell death and discuss current research and the latest therapeutic strategies to help understand TBI-mediated secondary injury.

Soy Isoflavone Improved Female Sexual Dysfunction of Mice Via Endothelial Nitric Oxide Synthase Pathway

Introduction

Female sexual dysfunction (FSD) is a common endocrine disease that impairs the quality of life for many women. The existing therapy strategies still have many disadvantages. It is necessary to explore new pharmacologic treatments that are effective and safe.

Aim

The aim of this study was to explore the effects of soy isoflavone (SI) on FSD in mice and the underlying mechanisms.

Methods and Main Outcome Measures

Laser Doppler flowmetry was used to determine vaginal blood flow. Serum hormone levels and histologic changes of the vagina were analyzed by enzyme-linked immunosorbent assay (ELISA) and by hematoxylin and eosin (H&E) and Masson’s trichome staining. The mRNA and protein expression of endothelial nitric oxide synthase (eNOS) was then evaluated by quantitative real-time polymerase chain reaction and western blot assays.

Results

Vaginal blood flow was found to be remarkably lower in adult mice, and SI was shown to increase vaginal blood flow in a dose-dependent manner (P < .05). The results of ELISA and H&E and Masson’s trichome staining suggest that SI had a positive effect on FSD, as evidenced by the levels of hormones in serum and histologic changes of the vagina, which changed consistently. In addition, the level of eNOS was positively correlated with the concentration of SI, and eNOS inhibitor was able to reverse the improvement in sexual function induced by SI.

Conclusion

Our study demonstrated that SI could improve sexual function by upregulating the eNOS pathway. Therefore, SI might serve as a promising candidate for the treatment of sexual dysfunction.

Zhang J, Zhu Y, Pan L, et al. Soy Isoflavone Improved Female Sexual Dysfunction of Mice Via Endothelial Nitric Oxide Synthase Pathway. Sex Med 2019; 7:345–351.

Effect of Gender on Chronic Intermittent Hypoxic Fosb Expression in Cardiorespiratory-Related Brain Structures in Mice

We aimed to delineate sex-based differences in neuroplasticity that may be associated with previously reported sex-based differences in physiological alterations caused by repetitive succession of hypoxemia-reoxygenation encountered during obstructive sleep apnea (OSA). We examined long-term changes in the activity of brainstem and diencephalic cardiorespiratory neuronal populations induced by chronic intermittent hypoxia (CIH) in male and female mice by analyzing Fosb expression. Whereas the overall baseline and CIH-induced Fosb expression in females was higher than in males, possibly reflecting different neuroplastic dynamics, in contrast, structures responded to CIH by Fosb upregulation in males only. There was a sex-based difference at the level of the rostral ventrolateral reticular nucleus of the medulla, with an increase in the number of FOSB/ΔFOSB-positive cells induced by CIH in males but not females. This structure contains neurons that generate the sympathetic tone and which are involved in CIH-induced sustained hypertension during waking hours. We suggest that the sex-based difference in neuroplasticity of this structure contributes to the reported sex-based difference in CIH-induced hypertension. Moreover, we highlighted a sex-based dimorphic phenomenon in serotoninergic systems induced by CIH, with increased serotoninergic immunoreactivity in the hypoglossal nucleus and a decreased number of serotoninergic cells in the dorsal raphe nucleus in male but not female mice. We suggest that this dimorphism in the neuroplasticity of serotoninergic systems predisposes males to a greater alteration of neuronal control of the upper respiratory tract associated with the greater collapsibility of upper airways described in male OSA subjects.

Redox Signaling in Neurotransmission and Cognition During Aging

SIGNIFICANCE

Oxidative stress increases in the brain with aging and neurodegenerative diseases. Previous work emphasized irreversible oxidative damage in relation to cognitive impairment. This research has evolved to consider a continuum of alterations, from redox signaling to oxidative damage, which provides a basis for understanding the onset and progression of cognitive impairment. This review provides an update on research linking redox signaling to altered function of neural circuits involved in information processing and memory. Recent Advances: Starting in middle age, redox signaling triggers changes in nervous system physiology described as senescent physiology. Hippocampal senescent physiology involves decreased cell excitability, altered synaptic plasticity, and decreased synaptic transmission. Recent studies indicate N-methyl-d-aspartate and ryanodine receptors and Ca²⁺ signaling molecules as molecular substrates of redox-mediated senescent physiology.

CRITICAL ISSUES

We review redox homeostasis mechanisms and consider the chemical character of reactive oxygen and nitrogen species and their role in regulating different transmitter systems. In this regard, senescent physiology may represent the co-opting of pathways normally responsible for feedback regulation of synaptic transmission. Furthermore, differences across transmitter systems may underlie differential vulnerability of brain regions and neuronal circuits to aging and disease.

FUTURE DIRECTIONS

It will be important to identify the intrinsic mechanisms for the shift in oxidative/reductive processes. Intrinsic mechanism will depend on the transmitter system, oxidative stressors, and expression/activity of antioxidant enzymes. In addition, it will be important to identify how intrinsic processes interact with other aging factors, including changes in inflammatory or hormonal signals. Antioxid. Redox Signal. 28, 1724-1745.

Estradiol Protects Against Cardiorespiratory Dysfunctions and Oxidative Stress in Intermittent Hypoxia

Study Objectives

We tested the hypothesis that estradiol (E2) protects against cardiorespiratory disorders and oxidative stress induced by chronic intermittent hypoxia (CIH) in adult female rats.

Methods

Sprague-Dawley female rats (230-250 g) were ovariectomized and implanted with osmotic pumps delivering vehicle or E2 (0.5 mg/kg/d). After 14 days of recovery, the rats were exposed to CIH (21%-10% O2: 8 h/d, 10 cycles per hour) or room air (RA). After 7 days of CIH or RA exposure, we measured arterial pressures (tail cuff), metabolic rate (indirect calorimetry), minute ventilation, the frequency of sighs and apneas at rest, and ventilatory responses to hypoxia and hypercapnia (whole body plethysmography). We collected the cerebral cortex, brainstem, and adrenal glands to measure the activity of NADPH and xanthine oxidase (pro-oxidant enzymes), glutathione peroxidase, and the mitochondrial and cytosolic superoxide dismutase (antioxidant enzymes) and measured lipid peroxidation and advanced oxidation protein products (markers of oxidative stress).

Results

CIH increased arterial pressure, the frequency of apnea at rest, and the hypoxic and hypercapnic ventilatory responses and reduced metabolic rate. CIH also increased oxidant enzyme activities and decreased antioxidant activity in the cortex. E2 treatment reduced body weight and prevented the effects of CIH.

Conclusions

E2 prevents cardiorespiratory disorders and oxidative stress induced by CIH. These observations may help to better understand the underlying mechanisms linking menopause and occurrence of sleep apnea in women and highlight a potential advantage of hormone therapy.

Species and Tissue Differences in β-Estradiol 17-Glucuronidation

Uridine 5'-diphosphate-glucuronosyltransferase (UGT) is expressed in the liver and extrahepatic tissues. One of the major metabolic pathways of β-estradiol (E2) is glucuronidation at the 17-hydroxy position by UGTs. This study was performed to determine E2 17-glucuronidation kinetics in human and rodent liver, small intestine, and kidney microsomes and to clarify the species and tissue differences. In the human liver and small intestine, Eadie-Hofstee plots exhibited biphasic kinetics, suggesting that E2 17-glucuronide (E17G) formation was catalyzed by more than two UGT isoforms in both tissues. The K_m values for E17G formation by the high-affinity enzymes in the human liver and small intestine were 1.79 and 1.12 µM, respectively, and corresponding values for the low-affinity enzymes were 3.72 and 11.36 µM, respectively. Meanwhile, E17G formation in the human kidney was fitted to the Hill equation (S₅₀=1.73 µM, n=1.63), implying that the UGT isoform catalyzing E17G formation in the kidney differed from that in the liver and small intestine. The maximum clearance for E17G formation in the human kidney was higher than the intrinsic clearance in the liver. E17G formation in the rat liver and kidney exhibited biphasic kinetics, whereas that in the small intestine was fitted to the Hill equation. In mice, all 3 tissues exhibited biphasic kinetics. In conclusion, we reported species and tissue differences in E2 17-glucuronidation, which occurred not only in the human liver but also in the extrahepatic tissues particularly the kidney.

Age and ischemia differentially impact mitochondrial ultrastructure and function in a novel model of age-associated estrogen deficiency in the female rat heart

Altered mitochondrial respiration, morphology, and quality control collectively contribute to mitochondrial dysfunction in the aged heart. Because myocardial infarction remains the leading cause of death in aged women, the present study utilized a novel rodent model to recapitulate human menopause to interrogate the combination of age and estrogen deficiency on mitochondrial ultrastructure and function with cardiac ischemia/reperfusion (I/R) injury. Female F344 rats were ovariectomized (OVX) at 15 months and studied at 24 months (MO OVX; n = 40) vs adult ovary intact (6 months; n = 41). Temporal declines in estrogen concomitant with increased visceral adipose tissue were observed in MO OVX vs adult. Following in vivo coronary artery ligation or sham surgery, state 3 mitochondrial respiration was selectively reduced by age in subsarcolemmal mitochondria (SSM) and by I/R in interfibrillar mitochondria (IFM); left ventricular maximum dP/dt was reduced in MO OVX (p < 0.05). Elevated cyclophilin D and exacerbated I/R-induced mitochondrial acetylation in MO OVX suggest permeability transition pore involvement and reduced protection vs adult (p < 0.05). Mitochondrial morphology by TEM revealed an altered time course of autophagy coordinate with attenuated Drp1 and LC3BII protein levels with age-associated estrogen loss (p < 0.05). Here, reductions in both SSM and IFM function may play an additive role in enhanced susceptibility to regional I/R injury in aged estrogen-deficient female hearts. Moreover, novel insight into altered cardiac mitochondrial quality control garnered here begins to unravel the potentially important regulatory role of mitochondrial dynamics on sustaining respiratory function in the aged female heart.

Antioxidant Expression Response to Free Radicals in Active Men and Women Fallowing to a Session Incremental Exercise; Numerical Relationship Between Antioxidants and Free Radicals

Background

Energy production is a necessary process to continue physical activities, and exercise is associated with more oxygen consumption and increase of oxidative stress. what seems important is the numerical relationship between antioxidant and free radicals. Although the activity of some enzymes increases with physical activities, but it is possible that gene expression of this enzyme is not changed during exercise.

Objectives

The aim of the present study is to investigate the antioxidant enzymes gene expression and changes in malondialdehyde (MDA) and total antioxidant capacity (TAC) levels in men and women affected by a session of incremental exercise and to carefully and numerically assess the relationship between MDA changes and gene expression and activity of antioxidant enzymes.

Materials and Methods

12 active men and 12 active women (21 - 24 years old) participated voluntarily in this study. Peripheral blood samples were taken from the subjects in three phases, before and after graduated exercise test (GXT) and 3 hours later (recovery).

Results

The gene expression of manganese superoxide dismutase (MnSOD) enzyme increased significantly in women in the recovery phase (P < 0.05). Catalase gene expression significantly increased in men in both phases (immediately & recovery) (P < 0.05). But the changes in active women were only significant immediately after the exercise. TAC levels increased significantly in men in the recovery phase and in active women immediately after the exercise (P < 0.05). MDA activity also increased significantly in men in both phases (P < 0.05). However, in women the increase was significant only in the recovery phase (P < 0.05). There was a reverse relationship between changes in MnSOD and copper- and zinc-containing superoxide dismutase (Cu/ZnSOD) levels and MDA in men (P < 0.05). In active women there was also a significant relationship between changes in MDA and gene expression of Cu/ZnSOD and TAC (P < 0.05).

Conclusions

The increase in free radicals during incremental exercises challenges gene expression and activity of antioxidant enzymes. However, despite the negative effects of free radicals, in women, activity and gene expression of antioxidant enzymes respond appropriately to free radicals.

Glutamine synthetase and alanine transaminase expression are decreased in livers of aged vs. young beef cows and GS can be upregulated by 17β-estradiol implants

Aged beef cows (≥ 8 yr of age) produce calves with lower birth and weaning weights. In mammals, aging is associated with reduced hepatic expression of glutamine synthetase (GS) and alanine transaminase (ALT), thus impaired hepatic Gln-Glu cycle function. To determine if the relative protein content of GS, ALT, aspartate transaminase (AST), glutamate transporters (EAAC1, GLT-1), and their regulating protein (GTRAP3-18) differed in biopsied liver tissue of (a) aged vs. young (3 to 4 yr old) nonlactating, nongestating Angus cows (Exp. 1 and 2) and (b) aged mixed-breed cows with and without COMPUDOSE (17β-estradiol) ear implants (Exp. 3), Western blot analyses were performed. In Exp. 1, 12 young (3.62 ± 0.01 yr) and 13 aged (10.08 ± 0.42 yr) cows grazed the same mixed forage for 42 d (August-October). In Exp. 2, 12 young (3.36 ± 0.01 yr) and 12 aged (10.38 ± 0.47 yr) cows were individually fed (1.03% of BW) a corn-silage-based diet to maintain BW for 20 d. For both Exp. 1 and 2, the effect of cow age was assessed by ANOVA using the MIXED procedure of SAS. Cow BW did not change ( ≥ 0.17). Hepatic ALT (78% and 61%) and GS (52% and 71%) protein content (Exp. 1 and 2, respectively) was decreased ( ≤ 0.01), whereas GTRAP3-18 (an inhibitor of EAAC1 activity) increased ( ≤ 0.01; 170% and 136%) and AST, GLT-1, and EAAC1 contents did not differ ( ≥ 0.17) in aged vs. young cows. In Exp. 2, free concentrations (nmol/g) of Glu, Ala, Gln, Arg, and Orn in liver homogenates were determined. Aged cows tended to have less ( = 0.10) free Gln (15.0%) than young cows, whereas other AA concentrations did not differ ( 0.26). In Exp. 3, 14 aged (> 10 yr) cows were randomly allotted ( = 7) to sham or COMPUDOSE (25.7 mg of 17β-estradiol) implant treatment (TRT), and had ad libitum access to alfalfa hay for 28 d. Blood and liver biopsies were collected 14 and 28 d after implant treatment. Treatment, time after implant (DAY), and TRT × DAY effects were assessed by ANOVA using the MIXED procedure of SAS. Cow BW was not affected ( ≥ 0.96). Implant increased ( ≤ 0.02) total plasma estradiol by 220% (5.07 vs. 1.58 pg/mL) and GS protein by 300%, whereas the relative content of other proteins was not altered ( ≥ 0.16). We conclude that hepatic expression of ALT and GS are reduced in aged vs. young cows, and administration of 17β-estradiol to aged cows increases plasma estradiol and hepatic GS, but not that of other proteins that support hepatic Glu metabolism.

Role of endothelin receptor antagonist; bosentan in cisplatin-induced nephrotoxicity in ovariectomized estradiol treated rats

Background: Endothelin-1 (ET-1) is a vasoconstrictor peptide that mediates cell proliferation, fibrosis, and inflammation. ET-1 has 2 receptors A and B.

Objectives: The present study investigated whether administration of ET-1 receptor type A antagonist leads to protect cisplatin (CP) induced nephrotoxicity in ovariectomized-estradiol (Es) treated rats.

Materials and Methods: Thirty-six ovariectomized Wistar rats were divided into 6 groups. Group 1 received CP (2.5 mg/kg/day) for one week. Groups 2 and 3 received 2 different doses of Es (0.25 and 0.5 mg/kg/week) for 3 weeks, but CP was started in the third week. Group 4 was treated as group 1, but bosentan (BOS, 30 mg/kg/day) was also added. Groups 5 and 6 treated similar to groups 2 and 3 but CP and BOS were added in the third week. At the end of the experiment, blood samples were obtained, and the animals were sacrificed for histopathological investigation of kidney tissue.

Results: The serum levels of creatinine (Cr) and blood urea nitrogen (BUN) increased by CP; however, BOS significantly elevated the BUN and Cr levels that were increased by CP administration (P < 0.05). Co-treatment of Es, BOS, and CP decreased the serum levels of BUN, Cr, and malondialdehyde (MDA) when compared with the group treated with BOS plus CP (P < 0.05). Such finding was obtained for kidney tissue damage score (KTDS). As expected, Es significantly increased uterus weight (P < 0.05). The groups were not significantly different in terms of serum and kidney nitrite, kidney weight (KW), and bodyweight

Conclusions: According to our findings, BOS could not protect renal functions against CP-induced nephrotoxicity. In contrast, Es alone or accompanied with BOS could protect the kidney against CP-induced nephrotoxicity via reduction of BUN, Cr, and KTDS.

Cerebral White Matter Lesions and Affective Episodes Correlate in Male Individuals with Bipolar Disorder

Background

Cerebral white matter lesions (WML) have been found in normal aging, vascular disease and several neuropsychiatric conditions. Correlations of WML with clinical parameters in BD have been described, but not with the number of affective episodes, illness duration, age of onset and Body Mass Index in a well characterized group of euthymic bipolar adults. Herein, we aimed to evaluate the associations between bipolar course of illness parameters and WML measured with volumetric analysis.

Methods

In a cross-sectional study 100 euthymic individuals with BD as well as 54 healthy controls (HC) were enrolled to undergo brain magnetic resonance imaging using 3T including a FLAIR sequence for volumetric assessment of WML-load using FSL-software. Additionally, clinical characteristics and psychometric measures including Structured Clinical Interview according to DSM-IV, Hamilton-Depression, Young Mania Rating Scale and Beck’s Depression Inventory were evaluated.

Results

Individuals with BD had significantly more (F = 3.968, p < .05) WML (Mdn = 3710mm3; IQR = 2961mm3) than HC (Mdn = 2185mm3; IQR = 1665mm3). BD men (Mdn = 4095mm3; IQR = 3295mm3) and BD women (Mdn = 3032mm3; IQR = 2816mm3) did not significantly differ as to the WML-load or the number and type of risk factors for WML. However, in men only, the number of manic/hypomanic episodes (r = 0.72; p < .001) as well as depressive episodes (r = 0.51; p < .001) correlated positively with WML-load.

Conclusions

WML-load strongly correlated with the number of manic episodes in male BD patients, suggesting that men might be more vulnerable to mania in the context of cerebral white matter changes.

Progesterone for neuroprotection in pediatric traumatic brain injury

OBJECTIVE

To provide an overview of the preclinical literature on progesterone for neuroprotection after traumatic brain injury and to describe unique features of developmental brain injury that should be considered when evaluating the therapeutic potential for progesterone treatment after pediatric traumatic brain injury.

DATA SOURCES

National Library of Medicine PubMed literature review.

STUDY SELECTION

The mechanisms of neuroprotection by progesterone are reviewed, and the preclinical literature using progesterone treatment in adult animal models of traumatic brain injury is summarized. Unique features of the developing brain that could either enhance or limit the efficacy of neuroprotection by progesterone are discussed, and the limited preclinical literature using progesterone after acute injury to the developing brain is described. Finally, the current status of clinical trials of progesterone for adult traumatic brain injury is reviewed.

DATA EXTRACTION AND DATA SYNTHESIS

Progesterone is a pleiotropic agent with beneficial effects on secondary injury cascades that occur after traumatic brain injury, including cerebral edema, neuroinflammation, oxidative stress, and excitotoxicity. More than 40 studies have used progesterone for treatment after traumatic brain injury in adult animal models, with results summarized in tabular form. However, very few studies have evaluated progesterone in pediatric animal models of brain injury. To date, two human phase II trials of progesterone for adult traumatic brain injury have been published, and two multicenter phase III trials are underway.

CONCLUSIONS

The unique features of the developing brain from that of a mature adult brain make it necessary to independently study progesterone in clinically relevant, immature animal models of traumatic brain injury. Additional preclinical studies could lead to the development of a novel neuroprotective therapy that could reduce the long-term disability in head-injured children and could potentially provide benefit in other forms of pediatric brain injury (global ischemia, stroke, and statue epilepticus).

Protective actions of 17β-estradiol and progesterone on oxidative neuronal injury induced by organometallic compounds

Steroid hormones synthesized in and secreted from peripheral endocrine glands pass through the blood-brain barrier and play a role in the central nervous system. In addition, the brain possesses an inherent endocrine system and synthesizes steroid hormones known as neurosteroids. Increasing evidence shows that neuroactive steroids protect the central nervous system from various harmful stimuli. Reports show that the neuroprotective actions of steroid hormones attenuate oxidative stress. In this review, we summarize the antioxidative effects of neuroactive steroids, especially 17β-estradiol and progesterone, on neuronal injury in the central nervous system under various pathological conditions, and then describe our recent findings concerning the neuroprotective actions of 17β-estradiol and progesterone on oxidative neuronal injury induced by organometallic compounds, tributyltin, and methylmercury.

Peripheral markers of oxidative stress and antioxidative defense in euthymia of bipolar disorder--Gender and obesity effects

INTRODUCTION

Oxidative and nitrosative stress are implicated in the pathogenesis of uni- and bipolar disorder. Herein we primarily sought to characterize markers of oxidative/nitrosative stress during euthymia in adults with bipolar disorder (BD). Oxidative markers were further evaluated in this BD sample in synopsis with excess overweight or obesity and/or comorbid metabolic syndrome (MetS).

METHODS

Peripheral markers of oxidative stress [i.e. thiobarbituric acid reactive substance, (TBARS), malondialdehyde (MDA), and carbonyl proteins] and antioxidant markers [e.g. total antioxidative capacity (TAC), superoxide dismutase (SOD), glutathione S-transferase (GST)] were obtained in a cohort of euthymic adults with BD (N=113) and compared to healthy controls (CG) (N=78). Additionally, anthropometric measures included the body mass index (BMI) [kg/m(2)], waist and hip circumference [cm], waist-to-hip-ratio (WHR), waist to height ratio (WtHR) as well as the IDF-defined MetS.

RESULTS

The major finding was a significantly decreased TAC in BD compared to the CG (p<0.01; BD: M 1.18, SD 0.47; CG: M 1.39, SD 0.49). MDA was significantly and TBARS by trend higher in the CG compared to the euthymic bipolar test persons (MDA: p<0.01, BD: M 0.70, SD 0.18; CG: M 0.81, SD 0.25; TBARS: p<0.1, BD: M 0.78, SD 0.28; CG: M 0.76, SD 0.30). The antioxidative enzyme GST was significantly elevated in both patients and controls (BD: M 298.24, SD 133.02; CG: M 307.27 SD 118.18). Subgroup analysis revealed that the CG with concurrent MetS and obesity had significantly elevated TAC when compared to CG without concurrent MetS (p<0.05, no MetS: M 1.33, SD 0.50; MetS: M 1.67, SD 0.32), as well as persons with BD with or without current MetS (no MetS: M 1.18, SD 0.44; MetS: M 1.15, SD 0.49). Significant correlations between GST and anthropometric variables were found in male study participants. Multivariate analysis indicated a significant gender effect concerning TBARS values in all patients and CG (p<0.01, females: M 0.73, SD 0.29; males: M 0.83, SD 0.28).

CONCLUSION

Euthymic bipolar adults exhibit peripheral evidence of a disturbed biosignature of oxidative stress and antioxidative defense. Male test persons showed significantly higher peripheral markers of oxidative stress than women- female sex may exert protective effects. Furthermore, the biosignature of oxidative stress obtained herein was more pronounced in males with concurrent metabolic disorders. Our results further extend knowledge by introducing the moderating influence of gender and obesity on oxidative stress and BD.

Neuroprotection for traumatic brain injury

Traumatic brain injury (TBI) is a major cause of mortality and morbidity worldwide. Despite extensive preclinical research supporting the effectiveness of neuroprotective therapies for brain trauma, there have been no successful randomized controlled clinical trials to date. TBI results in delayed secondary tissue injury due to neurochemical, metabolic and cellular changes; modulating such effects has provided the basis for neuroprotective interventions. To establish more effective neuroprotective treatments for TBI it is essential to better understand the complex cellular and molecular events that contribute to secondary injury. Here we critically review relevant research related to causes and modulation of delayed tissue damage, with particular emphasis on cell death mechanisms and post-traumatic neuroinflammation. We discuss the concept of utilizing multipotential drugs that target multiple secondary injury pathways, rather than more specific "laser"-targeted strategies that have uniformly failed in clinical trials. Moreover, we assess data supporting use of neuroprotective drugs that are currently being evaluated in human clinical trials for TBI, as well as promising emerging experimental multipotential drug treatment strategies. Finally, we describe key challenges and provide suggestions to improve the likelihood of successful clinical translation.

Estrogen plus progestin increase superoxide dismutase and total antioxidant capacity in postmenopausal women

OBJECTIVE

This cross-sectional study aimed to evaluate the behavior of blood antioxidant enzymes (superoxide dismutase (SOD), catalase and glutathione peroxidase), plasma total antioxidant capacity and oxidative damage (lipid oxidation and protein carbonyl levels) and their relationship with the serum levels of steroid hormones in premenopausal and postmenopausal women without and with estrogen alone (ET) or estrogen plus progestin therapy (EPT).

METHODS

Blood was collected from four groups of subjects: premenopausal women (n = 24), postmenopausal women without hormone therapy (n = 31), postmenopausal women with ET (n = 12) and postmenopausal women with EPT (n = 16).

RESULTS

The activities of the different SOD isoforms (CuZnSOD and MnSOD) and the plasma total antioxidant power were significantly higher in the postmenopausal women under EPT than in the postmenopausal women without hormone replacement therapy (HRT). Only CuZnSOD activity was increased in women receiving ET compared to the postmenopausal women without HRT. However, no differences were observed in the levels of lipid or protein oxidation or in the non-enzymatic plasma antioxidants (uric acid and albumin) among the groups. The duration of HRT and serum estrogen levels were positively correlated to the blood CuZnSOD activity and to plasma total antioxidant power, whereas the serum progesterone levels were positively correlated to CuZnSOD activity and negatively correlated to protein carbonyl groups. Interestingly, the total antioxidant power of plasma was positively correlated to CuZnSOD and glutathione peroxidase activities.

CONCLUSION

We conclude that EPT increases blood MnSOD and CuZnSOD activity in postmenopausal women, leading to an increased plasma total antioxidant capacity. This finding may be relevant to the prevention of oxidative stress-related disorders in postmenopausal women.

The effect of Momordica charantia intake on the estrogen receptors ESRα/ESRβ gene levels and apoptosis on uterine tissue in ovariectomy rats

Estrogen or combinational hormone therapy can protect to menopausal symptoms but exogenous estrogen therapy has some potential risks which in turns lead to the appearance of various diseases. In recent years plants with high phytoestrogen content are recommended as therapeutic agents for postmenopausal hormonal treatment. In this research, we investigated the effects of Momordica charantia (MC) on the estrogen production and E2 as well as anti-oxidative and anti-apoptotic role on the ovariectomy rat model. The rats were ovariectomized and fed on 2 g/kg of fruit extra of MC for 30 days by gavage. 17-β estradiol (E2) and 8-OHdG levels in serum, markers of oxidative damage of ROS and ESRα, ESRβ and NF-kB gene levels were measured in uterus horn tissue. Caspase-3, caspase-9, TNF-α, IL-6, IL-10, Bcl-2 and Nf-kB proteins expression were assessed by western blotting. Structural changes in tissue were examined with H&E staining. MC administration also stimulated the E2 production and ESRα/ESRβ gene levels and the inhibited oxidative damage. Furthermore, MC treatment enhanced anti-apoptotic and anti-inflammatory process and tissue regeneration. Data herein support that MC directly regulates uterine estrogen response and may serve as a new phytoestrogenic substance for the treatment of post-menopausal symptoms.

The neuroprotective effects of progesterone on traumatic brain injury: current status and future prospects

Traumatic brain injury is the leading cause of morbidity and mortality in young adults. The secondary injury in traumatic brain injury consists of a complex cascade of processes that simultaneously react to the primary injury to the brain. This cascade has been the target of numerous therapeutic agents investigated over the last 30 years, but no neuroprotective treatment option is currently available that improve neurological outcome after traumatic brain injury. Progesterone has long been considered merely a female reproductive hormone. Numerous studies, however, show that progesterone has substantial pleiotropic properties as a neuroprotective agent in both animal models and humans. Here, we review the increasing evidence that progesterone can act as a neuroprotective agent to treat traumatic brain injury and the mechanisms underlying these effects. Additionally, we discuss the current progress of clinical studies on the application of progesterone in the treatment of traumatic brain injuries.

Myosins Are Differentially Expressed under Oxidative Stress in Chronic Streptozotocin-Induced Diabetic Rat Brains

Diabetes mellitus is a disease characterized by persistent hyperglycemia, which may lead to brain tissue damage due to oxidative stress and also contributes to neuronal death and changes in synaptic transmission. This study evaluated the effect of oxidative stress and the use of antioxidants supplementation on myosins expression levels in the brains of chronic diabetic rats induced by streptozotocin. Lipid peroxidation, antioxidant enzymes activities, and myosins-IIB and -Va expressions at transcriptional and translational levels were examined after 90 days induction. The chronic effect of the diabetes led to the upregulation of superoxide dismutase (SOD) and catalase (CAT) activities, and the downregulation of glutathione peroxidase (GPx), but there was no statistically significant increase in the malondialdehyde (MDA) levels. These alterations were accompanied by high myosin-IIB and low myosin-Va expressions. Although the antioxidant supplementation did not interfere on MDA levels, the oxidative stress caused by chronic hyperglycemia was reduced by increasing SOD and restoring CAT and GPx activities. Interestingly, after supplementation, diabetic rats recovered only myosin-Va protein levels, without interfering on myosins mRNA levels expressed in diabetic rat brains. Our results suggest that antioxidant supplementation reduces oxidative stress and also regulates the myosins protein expression, which should be beneficial to individuals with diabetes/chronic hyperglycemia.

Neuroprotection by gonadal steroid hormones in acute brain damage requires cooperation with astroglia and microglia

The neuroactive steroids 17β-estradiol and progesterone control a broad spectrum of neural functions. Besides their roles in the regulation of classical neuroendocrine loops, they strongly influence motor and cognitive systems, behavior, and modulate brain performance at almost every level. Such a statement is underpinned by the widespread and lifelong expression pattern of all types of classical and non-classical estrogen and progesterone receptors in the CNS. The life-sustaining power of neurosteroids for tattered or seriously damaged neurons aroused interest in the scientific community in the past years to study their ability for therapeutic use under neuropathological challenges. Documented by excellent studies either performed in vitro or in adequate animal models mimicking acute toxic or chronic neurodegenerative brain disorders, both hormones revealed a high potency to protect neurons from damage and saved neural systems from collapse. Unfortunately, neurons, astroglia, microglia, and oligodendrocytes are comparably target cells for both steroid hormones. This hampers the precise assignment and understanding of neuroprotective cellular mechanisms activated by both steroids. In this article, we strive for a better comprehension of the mutual reaction between these steroid hormones and the two major glial cell types involved in the maintenance of brain homeostasis, astroglia and microglia, during acute traumatic brain injuries such as stroke and hypoxia. In particular, we attempt to summarize steroid-activated cellular signaling pathways and molecular responses in these cells and their contribution to dampening neuroinflammation and neural destruction. This article is part of a Special Issue entitled 'CSR 2013'.

NAD(P)H:quinone oxidoreductase 1 is induced by progesterone in cardiomyocytes

NAD(P)H: quinone oxidoreductase 1 (NQO1) is a ubiquitous flavoenzyme that catalyzes two-electron reduction of various quinones by utilizing NAD(P)H as an electron donor. Our previous study found that progesterone (PG) can protect cardiomyocytes from apoptosis induced by doxorubicin (Dox). Microarray analyses of genes induced by PG had led to the discovery of induction of NQO1 mRNA. We report here that PG induces NQO1 protein and its activity in a dose-dependent manner. Whereas NQO1 is well known as a target gene of Nrf2 transcription factor due to the presence of antioxidant response element (ARE) in the promoter, PG did not activate the ARE, suggesting Nrf2-independent induction of NQO1. To address the role of NQO1 induction in PG-induced cytoprotection, we tested the effect of NQO1 inducer β-naphthoflavone and inhibitor dicoumarol. Induction of NQO1 by β-naphthoflavone decreased Dox-induced apoptosis and potentiated the protective effect of PG as measured by caspase-3 activity. PG-induced NQO1 activity was inhibited with dicoumarol, which did not affect PG-induced cytoprotection. Dicoumarol treatment alone potentiated Dox-induced caspase-3 activity. These data suggest that while NQO1 plays a role in PG-induced cytoprotection, there are additional components contributing to PG-induced cytoprotection.

Neuroinflammation after traumatic brain injury: opportunities for therapeutic intervention

Traumatic brain injury (TBI) remains one of the leading causes of mortality and morbidity worldwide, yet despite extensive efforts to develop neuroprotective therapies for this devastating disorder there have been no successful outcomes in human clinical trials to date. Following the primary mechanical insult TBI results in delayed secondary injury events due to neurochemical, metabolic and cellular changes that account for many of the neurological deficits observed after TBI. The development of secondary injury represents a window of opportunity for therapeutic intervention to prevent progressive tissue damage and loss of function after injury. To establish effective neuroprotective treatments for TBI it is essential to fully understand the complex cellular and molecular events that contribute to secondary injury. Neuroinflammation is well established as a key secondary injury mechanism after TBI, and it has been long considered to contribute to the damage sustained following brain injury. However, experimental and clinical research indicates that neuroinflammation after TBI can have both detrimental and beneficial effects, and these likely differ in the acute and delayed phases after injury. The key to developing future anti-inflammatory based neuroprotective treatments for TBI is to minimize the detrimental and neurotoxic effects of neuroinflammation while promoting the beneficial and neurotrophic effects, thereby creating optimal conditions for regeneration and repair after injury. This review outlines how post-traumatic neuroinflammation contributes to secondary injury after TBI, and discusses the complex and varied responses of the primary innate immune cells of the brain, microglia, to injury. In addition, emerging experimental anti-inflammatory and multipotential drug treatment strategies for TBI are discussed, as well as some of the challenges faced by the research community to translate promising neuroprotective drug treatments to the clinic.

Vitamin E, Vitamin C, or Losartan Is Not Nephroprotectant against Cisplatin-Induced Nephrotoxicity in Presence of Estrogen in Ovariectomized Rat Model

Background. The nephroprotective effect of vitamins E and C or losartan against cisplatin (CP)- induced nephrotoxicity when they are accompanied by estrogen was investigated. Methods. The ovariectomized rats received estradiol valerate for two weeks. At the end of the first week, a single dose of CP (7 mg/kg, IP) was also administered, and they received placebo (group 1), vitamin E (group 2), vitamin C (group 3), or losartan (group 4) every day during the second week, and they were compared with another three control groups. Results. CP alone increased the serum levels of blood urea nitrogen (BUN), creatinine (Cr), and kidney tissue damage score (KTDS), significantly (P < 0.05), however at the presence of estradiol and CP, vitamin C, vitamin E, or losartan not only did not decrease these parameters, but also increased them significantly (P < 0.05). The serum level of superoxidase dismutase (SOD) was reduced by CP (P < 0.05), but it was increased when estradiol or estradiol plus vitamin C or losartan were added (P < 0.05). Conclusion. The particular pharmacological dose of estrogen used in this study abolish the nephroprotective effects vitamins C and E or losartan against CP-induced nephrotoxicity.

Long-term exercise treatment reduces oxidative stress in the hippocampus of aging rats

Exercise can exert beneficial effects on cognitive functions of older subjects and it can also play an important role in the prevention of neurodegenerative diseases. At the same time it is perceivable that limited information is available on the nature of molecular pathways supporting the antioxidant effects of exercise in the brain. In this study 12-month old, middle-aged female Wistar rats were subjected to daily moderate intensity exercise on a rodent treadmill for a period of 15weeks which covered the early aging period unmasking already some aging-related molecular disturbances. The levels of reactive oxygen species (ROS), the amount of protein carbonyls, the levels of antioxidant intracellular enzymes superoxide dismutases (SOD-1, SOD-2) and glutathione peroxidase (GPx) were determined in the hippocampus. In addition, to identify the molecular pathways that may be involved in ROS metabolism and mitochondrial biogenesis, the activation of 5'-AMP-activated protein kinase (AMPK), the protein level of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (mtTFA) were measured. Our results revealed a lower level of ROS associated with a reduced amount of protein carbonyls in the hippocampus of physically trained rats compared to sedentary controls. Furthermore, exercise induced an up-regulation of SOD-1 and GPx enzymes, p-AMPK and PGC-1α, that can be related to an improved redox balance in the hippocampus. These results suggest that long-term physical exercise can comprises antioxidant properties and by this way protect neurons against oxidative stress at the early stage of aging.

Quantitative proteomic analysis reveals novel mitochondrial targets of estrogen deficiency in the aged female rat heart

The incidence of myocardial infarction rises sharply at menopause, implicating a potential role for estrogen (E(2)) loss in age-related increases in ischemic injury. We aimed to identify quantitative changes to the cardiac mitochondrial proteome of aging females, based on the hypothesis that E(2) deficiency exacerbates age-dependent disruptions in mitochondrial proteins. Mitochondria isolated from left ventricles of adult (6 mo) and aged (24 mo) F344 ovary-intact or ovariectomized (OVX) rats were labeled with 8plex isobaric tags for relative and absolute quantification (iTRAQ; n = 5-6/group). Groups studied were adult, adult OVX, aged, and aged OVX. In vivo coronary artery ligation and in vitro mitochondrial respiration studies were also performed in a subset of rats. We identified 965 proteins across groups and significant directional changes in 67 proteins of aged and/or aged OVX; 32 proteins were unique to aged OVX. Notably, only six proteins were similarly altered in adult OVX (voltage-dependent ion channel 1, adenine nucleotide translocator 1, cytochrome c oxidase subunits VIIc and VIc, catalase, and myosin binding protein C). Proteins affected by aging were primarily related to cellular metabolism, oxidative stress, and cell death. The largest change occurred in monoamine oxidase-A (MAO-A), a source of oxidative stress. While acute MAO-A inhibition induced mild uncoupling in aged mitochondria, reductions in infarct size were not observed. Age-dependent alterations in mitochondrial signaling indicate a highly selective myocardial response to E(2) deficiency. The combined proteomic and functional approaches described here offer possibility of new protein targets for experimentation and therapeutic intervention in the aged female population.

17β-Estradiol and vitamin E modulates oxidative stress-induced kidney toxicity in diabetic ovariectomized rat

The aim of this study was to investigate the effects of vitamin E (alpha-tocopherol) and 17β-estradiol (E(2)) supplementation on malondialdehyde (MDA), glutathione (GSH), vitamin A, beta carotene, selenium-dependent glutathione peroxidase (GSH-Px), zinc-dependent superoxide dismutase (SOD), and copper/zinc-dependent catalase (CAT) values in the kidney of ovariectomized (OVX) diabetic rats. Forty-two female rats were randomly divided into seven equal groups as follows: group I, control; group II, OVX; group III, OVX+E(2); group IV, OVX+E(2)+alpha-tocopherol; group V, OVX+diabetic; group VI, OVX+diabetic+E(2); and group VII, OVX+diabetic+E(2)+alpha-tocopherol. E(2) (40 μg kg(-1)/day) and alpha-tocopherol (100 μg kg(-1)/day) were given. Bilateral ovariectomy was performed in all groups except group I. After 4 weeks, antioxidant and MDA levels in the kidney for all groups were analyzed. GSH-Px, CAT, SOD, GSH levels, vitamin A, and beta carotene levels were decreased in OVX group compared to those in the control group but MDA level was elevated via ovariectomy. However, E(2) and E(2)+alpha-tocopherol supplementations in OVX group was associated with an increase in the GSH-Px, GSH, CAT and Zn-SOD values, vitamin A, and beta carotene levels but a decrease in MDA levels in kidney. The MDA levels in the kidney of diabetic OVX rats were found higher than those in the control and OVX groups. However, GSH, GSH-Px, CAT, SOD, vitamin A, and beta carotene levels in kidney were lower in OVX diabetic rats. On the other hand, E(2) and E(2)+alpha-tocopherol supplementations to OVX diabetic rats have caused an increase in GSH-Px, CAT and SOD, GSH, vitamin A, and beta carotene levels but a decrease in MDA levels. In conclusion, the E(2) and E(2)+alpha-tocopherol supplementations to diabetic OVX and OVX rats may strengthen the antioxidant defense system by reducing lipid peroxidation, and therefore they may play a role in preventing renal disorders.

Estradiol modulates membrane-linked ATPases, antioxidant enzymes, membrane fluidity, lipid peroxidation, and lipofuscin in aged rat liver

Free radical production and oxidative stress are known to increase in liver during aging, and may contribute to the oxidative damage. These changes increase during menopausal condition in females when the level of estradiol is decreased. The objective of this study was to observe the changes in activities of membrane linked ATPases (Na⁺K⁺ ATPase, Ca²⁺ ATPase), antioxidant enzymes (superoxide dismutase, glutathione-S-transferase), lipid peroxidation levels, lipofuscin content and membrane fluidity occurring in livers of female rats of 3, 12 and 24 months age groups, and to see whether these changes are restored to 3 months control levels rats after exogenous administration of 17-β-estradiol (E2). The aged rats (12 and 24 months) were given subcutaneous injection of E2 (0.1 μg/g body weight) daily for one month. The results obtained in the present work revealed that normal aging was associated with significant decrease in the activities of membrane linked ATPases, antioxidant enzymes, membrane fluidity and an increase in lipid peroxidation and lipofuscin content in livers of aging female rats. The present study showed that E2 treatment reversed the changes to normal levels. E2 treatment may be beneficial in preventing some of the age related changes in the liver by increasing antioxidant defenses.

Association between plasma metabolites and gene expression profiles in five porcine endocrine tissues

Background

Endocrine tissues play a fundamental role in maintaining homeostasis of plasma metabolites such as non-esterified fatty acids and glucose, the levels of which reflect the energy balance or the health status of animals. However, the relationship between the transcriptome of endocrine tissues and plasma metabolites has been poorly studied.

Methods

We determined the blood levels of 12 plasma metabolites in 27 pigs belonging to five breeds, each breed consisting of both females and males. The transcriptome of five endocrine tissues i.e. hypothalamus, adenohypophysis, thyroid gland, gonads and backfat tissues from 16 out of the 27 pigs was also determined. Sex and breed effects on the 12 plasma metabolites were investigated and associations between genes expressed in the five endocrine tissues and the 12 plasma metabolites measured were analyzed. A probeset was defined as a quantitative trait transcript (QTT) when its association with a particular metabolic trait achieved a nominal P value < 0.01.

Results

A larger than expected number of QTT was found for non-esterified fatty acids and alanine aminotransferase in at least two tissues. The associations were highly tissue-specific. The QTT within the tissues were divided into co-expression network modules enriched for genes in Kyoto Encyclopedia of Genes and Genomes or gene ontology categories that are related to the physiological functions of the corresponding tissues. We also explored a multi-tissue co-expression network using QTT for non-esterified fatty acids from the five tissues and found that a module, enriched in hypothalamus QTT, was positioned at the centre of the entire multi-tissue network.

Conclusions

These results emphasize the relationships between endocrine tissues and plasma metabolites in terms of gene expression. Highly tissue-specific association patterns suggest that candidate genes or gene pathways should be investigated in the context of specific tissues.

Protective effects of 17β estradiol on altered age related neuronal parameters in female rat brain

Biological aging is a fundamental process observed in almost all living beings. During aging the brain experiences structural, molecular, and functional alterations. Aging in females and males is considered as the end of natural protection against age related diseases like osteoporosis, coronary heart disease, diabetes, Alzheimer's and Parkinson's disease. These changes increase during menopausal condition in females when the level of estradiol is decreased. The aim of the present study was to investigate the anti-aging and protective potential of 17β estradiol (E2) treatment on activities of membrane linked ATPases (Na⁺K⁺ ATPase, Ca²⁺ATPase), antioxidant enzymes (superoxide dismutases, glutathione-S-transferases), intrasynaptosomal calcium levels, membrane fluidity and neurolipofuscin in the brain of aging female rats of 3 months (young), 12 months (adult) and 24 months (old) age groups, and to see whether these changes are restored to normal levels after exogenous administration of E2 (0.1 μg/g body weight for one month).The results obtained in the present work revealed that normal aging was associated with significant decrease in the activities of membrane linked ATPases, antioxidant enzymes and an increase in neurolipofuscin, intrasynaptosomal calcium levels in brain of aging female rats. The present study showed that E2 treatment reversed the changes to near normal levels. E2 treatment appears to be beneficial in preventing some of the age related changes in the brain, an important anti-aging effect of the hormone.

Short- and long-term regulation of 3-hydroxy 3-methylglutaryl coenzyme A reductase by a 4-methylcoumarin

Dyslipidemia is one of the most significant risk factors for cardiovascular diseases. Cholesterol homeostasis is regulated by both the receptor-mediated endocytosis of Low Density Lipoproteins by LDL receptors and de novo cholesterol synthesis via the rate-limiting enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase. Although statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase substrate competitors, have revolutionized the management of cardiovascular diseases by lowering serum LDL, their side effects range from myalgia to rhabdomyolysis. Treatment with antioxidant compounds could represent an efficient alternative in the modulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity. Indeed it has already been demonstrated that the rise in reactive oxygen species levels causes the complete dephosphorylation and, in turn activation of the enzyme. Many coumarins and their derivatives have the special ability to scavenge reactive oxygen species or show a lipid lowering potential. Here we evaluated whether the coumarin, 4-methylesculetin could exert both the ability to scavenge ROS and to modulate 3-hydroxy-3-methylglutaryl coenzyme A reductase in HepG2 cell line where the enzyme activity dysregulation induced by reactive oxygen species has already been reported. The antioxidant property of 4-methylesculetin led to the reduction of 3-hydroxy-3-methylglutaryl coenzyme A reductase activation state through the increase of the enzyme phosphorylation. In addition, this coumarin showed the ability to modulate 3-hydroxy-3-methylglutaryl coenzyme A reductase protein levels both by transcriptional and degradational events independent of its antioxidant activity.

Physiological and biochemical effects of 17β estradiol in aging female rat brain

Aging in females and males is considered as the end of natural protection against age related diseases like osteoporosis, coronary heart disease, diabetes, Alzheimer's disease and Parkinson's disease. These changes increase during menopausal condition in females when the level of estradiol is decreased. The objective of this study was to observe the changes in activities of monoamine oxidase, glucose transporter-4 levels, membrane fluidity, lipid peroxidation levels and lipofuscin accumulation occurring in brains of female rats of 3 months (young), 12 months (adult) and 24 months (old) age groups, and to see whether these changes are restored to normal levels after exogenous administration of estradiol (0.1 μg/g body weight for 1 month). The results obtained in the present work revealed that normal aging was associated with significant increases in the activity of monoamine oxidase, lipid peroxidation levels and lipofuscin accumulation in the brains of aging female rats, and a decrease in glucose transporter-4 level and membrane fluidity. Our data showed that estradiol treatment significantly decreased monoamine oxidase activity, lipid peroxidation and lipofuscin accumulation in brain regions of aging rats, and a reversal of glucose transporter-4 levels and membrane fluidity was achieved, therefore it can be concluded from the present findings that estradiol's beneficial effects seemed to arise from its antilipofuscin, antioxidant and antilipidperoxidative effects, implying an overall anti-aging action. The results of this study will be useful for pharmacological modification of the aging process and applying new strategies for control of age related disorders.

Neuroprotection for traumatic brain injury: translational challenges and emerging therapeutic strategies

Traumatic brain injury (TBI) causes secondary biochemical changes that contribute to subsequent tissue damage and associated neuronal cell death. Neuroprotective treatments that limit secondary tissue loss and/or improve behavioral outcome have been well established in multiple animal models of TBI. However, translation of such neuroprotective strategies to human injury have been disappointing, with the failure of more than thirty controlled clinical trials. Both conceptual issues and methodological differences between preclinical and clinical injury have undoubtedly contributed to these translational difficulties. More recently, changes in experimental approach, as well as altered clinical trial methodologies, have raised cautious optimism regarding the outcomes of future clinical trials. Here we critically review developing experimental neuroprotective strategies that show promise, and we propose criteria for improving the probability of successful clinical translation.

Effects of growth hormone, melatonin, oestrogens and phytoestrogens on the oxidized glutathione (GSSG)/reduced glutathione (GSH) ratio and lipid peroxidation in aged ovariectomized rats

Ovariectomy constitutes a commonly used model in rats and mice for human menopause. After ovariectomy, an imbalance between oxidant production and antioxidant levels appears in favour of the former, with increased oxidative stress and consequently an acceleration of ageing. In the present work, the levels of reduced glutathione (GSH), a relevant antioxidant, and oxidized glutathione (GSSG), an oxidant compound, as well as lipid peroxidation (through malondialdehyde (MDA) levels), were studied in liver, heart, kidney and spleen homogenates of old (24 months of age) unovariectomized and ovariectomized female Wistar rats. The results showed a significant increase of the GSSG/GSH ratio, a marker of oxidative stress, and higher MDA production in all the studied organs of ovariectomized rats as compared with unovariectomized animals. These data confirm the idea that ovariectomy accelerates the ageing process. Administration of growth hormone (GH), melatonin (MEL) and oestrogens (OE), as well as soybean phytoestrogens (PE) for 10 weeks, between 22 and 24 months of age, was able to decrease oxidative stress in the investigated organs of ovariectomized old rats, therefore slowing down the ageing process in those animals.

Age-Related Hypercholesterolemia and HMG-CoA Reductase Dysregulation: Sex Does Matter (A Gender Perspective)

Although cardiovascular diseases are less prevalent in premenopausal women than in men, their occurrence in women increases at the onset of menopause, and the loss of female sex hormones contributes to the striking increase in cardiovascular morbidity and mortality in postmenopausal women. We present here a description of age-related disruption of lipid homeostasis, which particularly affects 3-hydroxy 3-methylglutaryl Coenzyme A reductase, the key rate-limiting enzyme in the cholesterol biosynthetic pathway. We further discuss the age- and gender-related dysregulation of this enzyme, providing new evidence for the different mechanisms driving dyslipidemia in elderly men and women. In addition, we introduce pharmacological methods of regulating HMGR and maintaining cholesterol homeostasis.

Progesterone treatment for brain injury: an update

Traumatic brain injury is a significant clinical problem for which there is still no effective treatment. Recent laboratory and clinical data demonstrate a potentially beneficial role for neurosteroids, such as progesterone and allopregnanolone, in the treatment of traumatic brain injury, ischemic stroke and some neurodegenerative disorders. Unlike single-target agents, progesterone affects many of the molecular and physiological processes in the cascade of secondary damage after a traumatic brain injury. This article updates a 2006 Future Neurology review of the research on progesterone and its metabolites in the treatment of traumatic brain injury, and presents new evidence that vitamin D deficiency can reduce progesterone neuroprotection, while combining progesterone with vitamin D produces better functional outcomes after TBI compared with eithertreatment alone.