Increased blood oxidative stress in experimental menopause rat model: the effects of vitamin A low-dose supplementation upon antioxidant status in bilateral ovariectomized rats

Protective effects of long-term nitrate administration against ovariectomy-induced kidney dysfunction in rats

BACKGROUND

Menopause is associated with higher risks of chronic kidney disease. We determined the effect of nitrate on ovariectomy-induced kidney dysfunction METHODS: Control, ovariectomized (OVX), control + nitrate, and OVX + nitrate female Wistar rats (n = 10/group); sodium nitrate (100 mg/L) administered in drinking water for 9 months. Glomerular filtration rate (GFR) and albumin excretion rate (AER) were calculated from serum and urine parameters. At month 9, serum and kidney levels of nitric oxide (NO) metabolites (NOx), oxidative stress indices, and mRNA expression of endothelial NO synthase (eNOS) were measured; with histological analyses of the kidney.

RESULTS

Compared to controls, OVX rats had lower GFR (31%, p = 0.0079), higher glomerular tuft volume (30%, p = 0.0402), and Bowman's capsule space (39%, p = 0.0224). OVX rats had lower serum NOx (33%, p = 0.0061) and kidney eNOS mRNA expression (34%, p = 0.0368). Nitrate administration to: (i) control rats increased serum NOx (59%, p < 0.0001), with no effect on other parameters; (ii) OVX rats increased serum (85%, p < 0.0001) and kidney (106%, p = 0.0008) NOx values, and restored kidney eNOS expression to normal value. Nitrate administration to OVX rats increased GFR (36%, p = 0.0361) and restored glomerular tuft volume and Bowman's capsule space to normal values. In OVX rats, it also increased serum catalase (CAT) activity, serum and kidney total antioxidant capacity (TAC), and decreased serum malondialdehyde (MDA).

CONCLUSIONS

Low-dose long-term nitrate administration protects against ovariectomy-induced kidney dysfunction in rats. This effect is associated with reducing ovariectomy-induced oxidative stress and restoring eNOS-derived NO deficiency in systemic circulation and the kidney.

Roflumilast ameliorates ovariectomy-induced depressive-like behavior in rats via activation of AMPK/mTOR/ULK1-dependent autophagy pathway

AIMS

Roflumilast, a well-known phosphodiesterase-4 (PDE-4) inhibitor, possess an anti-inflammatory activity with approved indications in chronic obstructive pulmonary disease. This study aimed to evaluate the neuroprotective role of roflumilast in ovariectomy (OVX)-induced depressive-like behavior in female rats and to shed light on a potential autophagy enhancing effect.

MAIN METHODS

Rats were randomly divided into four groups: sham, OVX, OVX + roflumilast (1 mg/kg, p.o), and OVX + roflumilast + chloroquine (CQ) (50 mg/kg, i.p). Drugs were administered for 4 weeks starting 2 weeks after OVX.

KEY FINDINGS

Roflumilast improved the depressive-like behaviors observed in OVX rats as evidenced by decreasing both forced swimming and open field immobility times while, increasing % sucrose preference and number of open field crossed squares. Histopathological analysis provides further evidence of roflumilast's beneficial effects, demonstrating that roflumilast ameliorated the neuronal damage caused by OVX. Roflumilast antidepressant potential was mediated via restoring hippocampal cAMP and BDNF levels as well as down-regulating PDE4 expression. Moreover, roflumilast revealed anti-inflammatory and anti-apoptotic effects via hindering TNF-α level and diminishing Bax/Bcl2 ratio. Roflumilast restored the autophagic function via up-regulation of p-AMPK, p-ULK1, Beclin-1 and LC3II/I expression, along with downregulation of P62 level and p-mTOR protein expression. The autophagy inhibitor CQ was used to demonstrate the suggested pathway.

SIGNIFICANCE

The present study revealed that roflumilast showed an anti-depressant activity in OVX female rats via turning on AMPK/mTOR/ULK1-dependent autophagy pathway; and neurotrophic, anti-inflammatory, and anti-apoptotic activities. Roflumilast could offer a more secure alternative to hormone replacement therapy for postmenopausal depression treatment.

Association between Dietary Total Antioxidant Capacity of Antioxidant Vitamins and the Risk of Stroke among US Adults

The intake of antioxidant vitamins can scavenge free radicals and reduce oxidative stress, which may be beneficial for stroke. However, the relationship between total antioxidant capacity (TAC) of antioxidant vitamins and stroke is controversial. This study aims to investigate the association between dietary TAC and the risk of stroke in US adults. This study included participants over 20 years old from the 2001-2018 National Health and Nutrition Examination Survey (NHANES). Data from two 24 h dietary recalls were used to estimate the usual intake of antioxidant vitamins. TAC was calculated by the vitamin C equivalent antioxidant capacity reference values of individual antioxidant vitamins. Survey-weighted generalized linear models were performed to evaluate the relationship between TAC and the risk of stroke. A restricted cubic spline regression model was used to investigate the dose-response association. A total of 37,045 participants was involved, of whom 1391 suffered a stroke. Compared with the first tertile, the participants in the second tertile of TAC showed a lower risk of stroke (OR = 0.788, 95% CI: 0.662, 0.936) after adjusting for potential risk factors. The dose-response analysis showed a gradual increase in the risk of stroke as TAC decreases. Subgroups analyses indicated that this association was primarily in the population of those aged over 60 years old, who were female, consumed alcohol, were a former smoker and inactive. The sensitivity analysis presented consistent results. These results suggest that deficiency of dietary TAC was associated with an increased risk of stroke, particularly in populations with underlying oxidative stress injury.

Identification of the Active Ingredient and Beneficial Effects of Vitex rotundifolia Fruits on Menopausal Symptoms in Ovariectomized Rats

Estrogen replacement therapy is a treatment to relieve the symptoms of menopause. Many studies suggest that natural bioactive ingredients from plants resemble estrogen in structure and biological functions and can relieve symptoms of menopause. The fruit of V. rotundifolia, called "Man HyungJa" in Korean, is a traditional medicine used to treat headache, migraine, eye pain, neuralgia, and premenstrual syndrome in Korea and China. The aim of the present study was to confirm that V. rotundifolia fruit extract (VFE) exerts biological functions similar to those of estrogen in menopausal syndrome. We investigated its in vitro effects on MCF-7 cells and in vivo estrogen-like effects on weight gain and uterine contraction in ovariectomized rats. Using the polar extract, the active constituents of VFE (artemetin, vitexicarpin, hesperidin, luteolin, vitexin, and vanillic acid) with estrogen-like activity were identified in MCF-7 cells. In animal experiments, the efficacy of VFE in ameliorating body weight gain was similar to that of estrogen, as evidenced from improvements in uterine atrophy. Vitexin and vitexicarpin are suggested as the active constituents of V. rotundifolia fruits.

Neuromodulatory effect of curcumin on catecholamine systems and inflammatory cytokines in ovariectomized female rats

Anti-inflammatory products may represent the future for depressive disorder therapies. Curcumin (CUR) is a polyphenol and an active component of the turmeric plant Curcuma longa. The aim of this study was to investigate the impact of CUR, as a natural anti-inflammatory agent, on neuro-inflammation related to depression and compare it with the effects of fluoxetine (FLX) and estradiol (E2 ) in ovariectomized (OVX) rats. The experimental animals were divided into the following five treatment groups (n = 10): sham-operated, OVX, OVX-E2 (100 μg/kg, im, every other day), OVX-FLX (20 mg/kg, ip, daily), and OVX-CUR (100 mg/kg, po, daily). The results indicated that CUR improved the animals' performances in the open field test and modulated dopamine (DA) and norepinephrine levels in several brain regions compared with the OVX group. CUR resulted in the down-regulation of monoamine oxidase b and up-regulation of tyrosine hydroxylase, as well asDA receptor mRNA in the limbic region. In addition, CUR significantly attenuated the production of serum corticosterone hormone, tumour necrosis factor-alpha, interleukin-β1, interleukin-6, and nitric oxide in the limbic system. Furthermore, CUR normalized malondialdehyde levels and led to a significant upsurge in total antioxidant capacity, compared with the OVX group. Consequently, CUR, besides being harmless, was efficient against inflammation and oxidative-nitrosative stress, showing a greater effect on DA receptor expression than FLX and E2 in OVX rats.

Effects of foetal and breastfeeding exposure to methylmercury (MeHg) and retinol palmitate (Vitamin A) in rats: Redox parameters and susceptibility to DNA damage in liver

Methylmercury (MeHg) is known to be a chemical that poses a risk to public health. Exposure to MeHg and vitamin A (VitA) occurs through the ingestion of fish, present in the diet of most pregnant women. The absorption of these elements generates oxidative stress and can generate adaptations for future stressful events. Here, we assessed how exposure to VitA and/or MeHg during the fetal and breastfeeding period modulates the toxicity of MeHg reexposure in adulthood. We focus on redox systems and repairing DNA damage. Male rats (n = 50), were divided into 5 groups. Control received mineral oil; The VitA group received VitA during pregnancy, during breastfeeding and was exposed to MeHg in adulthood; VitA + MeHg received VitA and MeHg during pregnancy and breastfeeding and was exposed to MeHg in adulthood. The single exposure group (SE) was exposed to MeHg only in adulthood; and the MeHg group was pre-exposed to MeHg during pregnancy and breastfeeding and re-exposed to MeHg in adulthood. After treating the animals, we evaluated the redox status and the level of DNA damage in all rats. The results revealed that MeHg significantly decreased the activity of glutathione peroxidase (GPx) and sulfhydryl levels and increased the activity of superoxide dismutase (SOD), glutathione transferase, glutathione and carbonyl in all exposed groups. These results suggest that the second exposure to MeHg directly altered the effects of oxidation and that there were no specific effects associated with exposure during the fetal and breastfeeding periods. In addition, our findings indicate that MDA levels increased in MeHg and SE levels and no differences in MDA levels were observed between the VitA and MeHg + VitA groups. We also observed that animals pretreated exclusively with VitA showed residual damage similar to the control's DNA, while the other groups showed statistically higher levels of damage. In conclusion, low doses of MeHg and VitA during fetal and breastfeeding periods were unable to condition an adaptive response to subsequent exposure to MeHg in adulthood in relation to the observed levels of oxidative damage assessed after exposure.

Morphometric Effects of Whole-Body Vibration on the Bone in a Rat Model of Postmenopausal Osteoporosis

OBJECTIVE

The purpose of this study was to analyze the morphometric effects of mechanical vibration with a duration of 4 or 8 weeks on the femur of oophorectomized Wistar rats.

METHODS

Sixty-four female rats were submitted to oophorectomy or a sham operation, and each of those 2 groups were randomized into 4 groups: untreated and euthanized at week 12, untreated and euthanized at week 16, treated for 4 weeks and euthanized at week 12, and treated for 8 weeks and euthanized at week 16. The vibration treatment was performed for 10 min/d, with a frequency of 60 Hz, 3 d/wk. The rats were then euthanized and the right femur dissected. Subsequently, histomorphometric analysis was performed on the proximal epiphysis and diaphysis of the spongy and cortical bone, respectively.

RESULTS

As expected, the oophorectomy groups presented reduction of spongy and cortical bone tissue. Further, the vibration therapy of 4 and 8 weeks' duration in the oophorectomized groups led to increased bone mass, observed as an increased percentage of spongy tissue, and increased thickness and percentage of cortical tissue. However, the variables of femoral neck diameter, mean area of the shaft, and number of osteocytes were not altered by oophorectomy and vibration.

CONCLUSION

The mechanical vibration was effective in increasing the bone mass of the femur of oophorectomized Wistar rats, observed by increasing the percentage of spongy bone and increasing the percentage and thickness of cortical bone.

Topical capsaicin cream with moderate exercise protects against hepatic steatosis, dyslipidemia and increased blood pressure in hypoestrogenic obese rats

BACKGROUND

The aim of this study was to evaluate the effects of capsaicin (Cap), moderate exercise (Ex), and their combination on arterial blood pressure (BP) and metabolic complications in hypoestrogenic (HE) obese (HEOb) rats. Female Wistar rats were ovariectomized and given 300 g L^-1 sucrose solution (HEOb), or purified water (HE) ad libitum, for 28 weeks. After shaving the abdominal skin, cold cream vehicle was applied to sedentary (Sed) and exercise (Ex) groups, and 0.75 g kg^-1 Cap cream was applied to Ex groups. Ex groups ran on a treadmill every day for 20 min at speeds from 0.15 to 0.3 m s^-1 . For combination groups (Cap + Ex), topical Cap was applied 90 min before Ex. The treatments were performed for 6 weeks, and BP was recorded before and at the end of the experimental protocol. The animals were killed by decapitation, and blood and tissues were obtained to perform oxidative profile, as well as to undertake biochemical and histologic studies.

RESULTS

Compared with individual treatments, the combined therapy (Cap + Ex) in HEOb rats caused a higher reduction in the caloric intake, body weight, abdominal fat percentage, oxidative stress, and hepatic steatosis. In HEOb groups, Cap was the only treatment that reduced BP and prevented dyslipidemia and oxidative stress.

CONCLUSION

The present data show that Cap improves the metabolic alterations induced by obesity and hypoestrogenism, suggesting that Cap can be considered as an excellent candidate for therapy of these clinical conditions. © 2020 Society of Chemical Industry.

Effect of herbal extract Eurycoma longifolia (Physta®) on female reproductive hormones and bone biochemical markers: an ovariectomised rat model study

BACKGROUND

Each year 1.5 million women experience menopause when menstrual cycles cease resulting from the loss of ovarian function and oestrogen deprivation, a hormone that helps prevent bone loss. This study investigated the effects of Physta®, a standardized herbal extract of Eurycoma longifolia Jack (PEL), on hormonal balance and parameters associated with hormonal imbalance, namely body and uterus weight and bone biochemical markers relevant in menopausal symptoms.

METHODS

Forty-eight Sprague Dawley rats were randomly divided into six groups of eight rats each: (A) Sham operated; control (B) Untreated (ovariectomised (OVX) with vehicle), (C) PEL 100 (OVX + 100 mg/kg body weight (bw)), (D) PEL 300 (OVX + 300 mg/kg bw), (E) PEL 500 (OVX + 500 mg/kg bw) and (F) Positive control, testosterone undecanoate (TU) (OVX+ 10 mg/kg bw). Group A and B received daily oral administrations of the vehicle, Group C-E received daily oral administration of PEL and Group F received testosterone undecanoate intramuscularly weekly. At the end of 8 weeks, serum calcium, phosphate, bone alkaline phosphatase (BALP), osteocalcin, follicle stimulating hormone (FSH), luteinising hormone (LH), oestrogen, progesterone and testosterone were measured, then the animals were sacrificed and uterus was isolated, while weight was recorded in all experimental groups.

RESULTS

Treatment of OVX rats with PEL at a dose of 500 mg/kg showed decreased serum FSH (P < 0.001, 4.25 ± 0.22 mIU/ml) and LH (NS, 4.07 ± 0.12 mIU/ml), while there was a significant increase in progesterone (P < 0.05, 2.48 ± 0.08 ng/ml) and oestrogen (P < 0.05, 11.02 ± 0.13 pg/ml) levels when compared to untreated group. PEL treatment at doses of 100 mg/kg, 300 mg/kg and 500 mg/kg showed a non-significant but increasing trend in serum calcium, phosphate, bone alkaline phosphate and testosterone levels. Ovariectomy resulted in a significant reduction (P < 0.001, 238.81 ± 5.39 mg) in uterus weight in the ovariectomised rats, which was alleviated in all PEL treated ovariectomised rats with an increasing trend of uterine weight.

CONCLUSION

The results suggest that PEL could be protective and beneficial for the management of reproductive hormone and bone markers. Therefore, it could be used to address hormonal imbalances and symptoms associated with menopause.

Reproductive Regulation and Oxidative Stress Alleviation of Chinese Herbal Medicine Therapy in Ovariectomised Mouse Model

In Taiwan, the herbal formula B401 is considered as a health supplement for middle-aged women that can alleviate sweating, anxiety, and sleep disorders. However, the relevant mechanisms are still unclear. In this study, we evaluated the beneficial effects of the herbal formula B401 therapy in the reproductive regulation of ovariectomised mice. Female ICR mice were randomised into four groups: wild-type (WT) mice with sham treatment, wild-type mice treated with the herbal formula B401, bilateral ovariectomised (OVX) mice with sham treatment, and bilateral ovariectomised mice treated with the herbal formula B401. Mice were orally given the herbal formula B401 at a dose of 30 mg/kg bw/day for 2 weeks. At the end of oral treatment with sham or the herbal formula B401, levels of reactive oxygen species (ROS), calcium, phosphorus, and estradiol-17β in the blood; uterine weight and endometrial thickness; and expressions of estrogen receptor α (ERα), estrogen receptor β (ERβ), progesterone receptor (PR), vascular endothelial growth factor (VEGF), and superoxide dismutase 2 (SOD2) in the uterine tissue were examined and then compared among the four groups of mice. We found that OVX mice decreased levels of calcium, phosphorus, and estradiol-17β in the blood, decreased uterine weight and endometrial thickness, and decreased expressions of ERα, ERβ, PR, and SOD2 in the uterine tissue but increased blood ROS levels compared with those of WT mice. In addition, OVX mice with the herbal formula B401 therapy can increase levels of calcium, phosphorus, and estradiol-17β in the blood, increase uterine weight and endometrial thickness, and increase expressions of ERα, ERβ, PR, VEGF, and SOD2 in the uterine tissue but decrease blood ROS levels. Our results may provide reasonable explanation for the reproductive regulation of the herbal formula B401 therapy.

Influence of oophorectomy on glycemia and lipidogram

PURPOSE

To verify the influence of oophorectomy on lipidogram and glycemia.

METHODS

Fifty six female rats were divided into the following 7 groups (n = 8): group 1 - sham group, group 2 - oophorectomy 30 days, group 3 - oophorectomy 35 days, group 4 - oophorectomy 40 days, group 5 - oophorectomy 45 days, group 6 - oophorectomy 70 days, group 7 - oophorectomy 55 days. Animals were following by number of days according the group. Was evaluated the serum levels of glucose and lipid profile.

RESULTS

The oophorectomized rats presented higher glycemia. Groups 3, 4, 6 and 7 had a higher glycemia and LDL levels (except for group 6) and groups 6 and 7 had lowest levels of HDL. Group 7 had highest level of VLDL than oophorectomy groups. There was no difference in triglycerides levels.

CONCLUSION

Oophorectomy was related to dyslipidemia and insulin resistance, mainly after 50th days.

The Effects of Sinapic Acid on the Development of Metabolic Disorders Induced by Estrogen Deficiency in Rats

Sinapic acid is a natural phenolic acid found in fruits, vegetables, and cereals, exerting numerous pharmacological effects. The aim of the study was to investigate the influence of sinapic acid on biochemical parameters related to glucose and lipid metabolism, as well as markers of antioxidant abilities and parameters of oxidative damage in the blood serum in estrogen-deficient rats. The study was performed on 3-month-old female Wistar rats, divided into 5 groups, including sham-operated control rats, ovariectomized control rats, and ovariectomized rats administered orally with estradiol (0.2 mg/kg) or sinapic acid (5 and 25 mg/kg) for 28 days. The levels of estradiol, progesterone, interleukin 18, insulin, glucose, fructosamine, lipids, and enzymatic and nonenzymatic antioxidants (superoxide dismutase, catalase, and glutathione); total antioxidant capacity; and oxidative damage parameters (thiobarbituric acid-reactive substances, protein carbonyl groups, and advanced oxidation protein products) were determined in the serum. Estradiol counteracted the carbohydrate and cholesterol metabolism disorders induced by estrogen deficiency. Sinapic acid increased the serum estradiol concentration; decreased insulin resistance and the triglyceride and total cholesterol concentrations; and favorably affected the parameters of antioxidant abilities (reduced glutathione, superoxide dismutase) and oxidative damage (advanced oxidation protein products).

Estimation of tissue and crevicular fluid oxidative stress marker in premenopausal, perimenopausal and postmenopausal women with chronic periodontitis

OBJECTIVES

The aim of this study was to estimate tissue and gingival crevicular fluid (GCF) levels of the oxidative stress marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) in premenopausal, perimenopausal and postmenopausal women with chronic periodontitis.

BACKGROUND

Oxidative stress has been implicated in the etiopathogenesis of periodontitis and menopause induces oxidative stress.

MATERIALS AND METHODS

According to Stages of Reproductive Aging Workshop (STRAW) criteria, women diagnosed with periodontitis were subdivided into three groups of 31 participants each 1. Premenopausal 2. Perimenopausal and 3. Postmenopausal. GCF and gingival tissue samples were collected from sites with maximum probing depth. Tissue DNA was extracted from the gingival sample and 8-OHdG in the extracted DNA, and GCF samples were measured using ELISA.

RESULTS

There was a highly significant difference in the overall GCF 8-OHdG levels among the three groups with the pairwise difference being highly significant between the premenopausal-postmenopausal groups and perimenopausal-postmenopausal groups. However, no overall significant differences in tissue 8-OHdG levels were found among the three groups. Pairwise, highly significant differences were found between the premenopausal-postmenopausal groups and perimenopausal-postmenopausal groups for tissue 8-OHdG levels. No significant correlations were found between various measure of periodontal disease and GCF/tissue 8-OHdG levels among all the groups.

CONCLUSION

Premenopausal-postmenopausal and perimenopausal-postmenopausal transition resulted in significant increase in tissue and GCF 8-OHdG levels. However, no association was found between stages of reproductive ageing and tissue levels of 8-OHdG.

Antioxidant Effect of Fructus Ligustri Lucidi Aqueous Extract in Ovariectomized Rats Is Mediated through Nox4-ROS-NF-κB Pathway

Purpose: This study is designed to explore whether Fructus ligustri lucidi (FLL) exhibits antioxidant effect in ovariectomized (OVX) rats, and to identify the signaling pathway involved in this process.

Methods: OVX rats were treated with FLL aqueous extract (3.5 g/kg) for 12 weeks. Serum, uteri, and tibias were harvested from the rats and the levels of total antioxidant capacity (TAC), nitric oxide (NO), malondialdehyde (MDA), 8-hydroxy-desoxyguanosine (8-OHdG), and superoxide dismutase (SOD) were determined. Changes in the levels of NF-κB-p65, phosphorylation of NF-κB-p65 (NF-κB-pp65), NF-κB inhibitor alpha (IκBα), phosphorylation of IκBα (p-IκBα), and NADPH oxidase 4 (Nox4) in uteri and tibias were determined by western blot, immunofluorescent and immunohistochemical analysis, respectively. In addition, the expression of cytochrome C (Cyto-C) and B-cell lymphoma-2 (Bcl-2) were determined in the tibias of rats. Histopathological changes in the bones were evaluated by hematoxylin-eosin staining. Bone mineral density (BMD) was determined in rat femurs by dual X-ray absorptiometry.

Results: Treatment of OVX rats with FLL aqueous extract improved redox homeostasis by increasing the levels of TAC and NO as well as decreasing the levels of MDA and 8-OHdG in serum, tibias, and uteri. Further, FLL extract also downregulated the expression of Nox4, NF-κB-p65, NF-κB-pp65, and p-IκBα in the uteri and tibias. Furthermore, administration of FLL–OVX rats increased Bcl-2 expression and prevented cytoplasmic release of mitochondrial Cyto-C in the tibias. In addition, FLL treatment also improved bone microstructure and increased cortical bone thickness as well as increased BMD values in the femurs of OVX rats.

Conclusions: FLL treatment may suppress oxidative stress response in OVX rats via regulating the Nox4/ROS/NF-κB signaling pathway. These results suggest the potential of using FLL as a natural antioxidant agent in preventing the development of osteoporosis.

Effects of topical capsaicin combined with moderate exercise on insulin resistance, body weight and oxidative stress in hypoestrogenic obese rats

BACKGROUND

Hypoestrogenic (HE) women are one of the most vulnerable groups for the development of obesity and its complications. Capsaicin and exercise have demonstrated to reduce body weight and to improve insulin sensitivity in different animal models, but it is unknown whether their combination could be useful in HE obese females.

METHODS

We investigated whether topical capsaicin, exercise or their combination had better therapeutic effects in an obesity-hypoestrogenism model. Ovariectomized Wistar rats were given a 30% sucrose solution (HE-Obese (HEOb)) or purified water (HE) during 28 weeks ad libitum; four experimental groups per each condition. After shaving the abdominal skin, cold cream vehicle was applied to the Sedentary groups (Sed) and capsaicin cream 0.075% (0.6 mg kg^-1 per day) to the Capsaicin groups (Cap). Exercise (Ex) groups ran on a treadmill every day for 20 min at speeds from 9 to 18 m per min increased every 10 days; combination groups (Cap+Ex) were given topical capsaicin 90 min before exercise. The treatments were performed for 6 weeks, and caloric intake and body weight were monitored. At the end of the experimental protocol, glucose tolerance tests were performed, the animals were killed by decapitation; blood and organs were obtained to perform oxidative profile, histology, biochemical analyses and Western blot.

RESULTS

In HEOb rats, the combined therapy reduced caloric intake, body weight and abdominal fat in a higher proportion than the individual treatments; it also decreased insulin resistance (IR), oxidative stress and pancreatic islet size. It was the only treatment that significantly increased p-AMPK levels in the soleus muscle. In HE rats, topical capsaicin was the only treatment that reduced glucose intolerance and improved the oxidative profile in a higher proportion than the combined therapy or Ex alone.

CONCLUSIONS

Capsaicin per se or its combination with moderate exercise could be a useful therapy against complications linked to obesity-IR in HE females.

Curcumin Supplementation Decreases Intestinal Adiposity Accumulation, Serum Cholesterol Alterations, and Oxidative Stress in Ovariectomized Rats

The aim of this study was to investigate the potential of curcumin oral supplementation (50 and 100 mg/Kg/day, for 30 days) in circumventing menopause-associated oxidative stress and lipid profile dysfunctions in a rat ovariectomy (OVX) model. Female Wistar rats were operated and randomly divided into either sham-operated or OVX groups. Sham-operated group (n = 8) and one OVX group (n = 11) were treated with vehicle (refined olive oil), and the other two OVX groups received curcumin at 50 or 100 mg/Kg/day doses (n = 8/group). OVX vehicle-treated animals presented a higher deposition of intestinal adipose tissue as well as increased serum levels of IL-6, LDL, and total cholesterol when compared to sham-operated rats. In addition, several oxidative stress markers in serum, blood, and liver (such as TBARS, carbonyl, reduced-sulphydryl, and nonenzymatic antioxidant defenses) were altered toward a prooxidant status by OVX. Interestingly, curcumin supplementation attenuated most of these parameters to sham comparable values. Thus, the herein presented results show that curcumin may be useful to ameliorate lipid metabolism alterations and oxidative damage associated with hormone deprivation in menopause.

The accumulation of brain water-free sodium is associated with ischemic damage independent of the blood pressure in female rats

Estrogen deficiency worsens ischemic stroke outcomes. In ovariectomized (OVX(+)) rats fed a high-salt diet (HSD), an increase in the body Na(+)/water ratio, which characterizes water-free Na(+) accumulation, was associated with detrimental vascular effects independent of the blood pressure (BP). We hypothesized that an increase in brain water-free Na(+) accumulation is associated with ischemic brain damage in OVX(+)/HSD rats. To test our hypothesis we divided female Wistar rats into 4 groups, OVX(+) and OVX(-) rats fed HSD or a normal diet (ND), and subjected them to transient cerebral ischemia. The brain Na(+)/water ratio was increased even in OVX(+)/ND rats and augmented in OVX(+)/HSD rats. The increase in the brain Na(+)/water ratio was positively correlated with expansion of the cortical infarct volume without affecting the BP. Interestingly, OVX(+) was associated with the decreased expression of ATP1α3, a subtype of the Na(+) efflux pump. HSD increased the expression of brain Na(+) influx-related molecules and the mineralocorticoid receptor (MR). The pretreatment of OVX(+)/HSD rats with the MR antagonist eplerenone reduced brain water-free Na(+) accumulation, up-regulated ATP1α3, down-regulated MR, and reduced the cortical infarct volume. Our findings show that the increase in the brain Na(+)/water ratio elicited by estrogen deficiency or HSD is associated with ischemic brain damage BP-independently, suggesting the importance of regulating the accumulation of brain water-free Na(+). The up-regulation of ATP1α3 and the down-regulation of MR may provide a promising therapeutic strategy to attenuate ischemic brain damage in postmenopausal women.

Effects of chronic sodium alendronate on depression and anxiety in a menopausal experimental model

OBJECTIVE

During menopause, lower levels of estrogen may induce bone resorption as well as anxiety and depression. Bisphosphonates represent the first choice in the treatment of osteoporosis and no data are available concerning their effects on comorbid behavior alterations. Therefore, in this study, we evaluated the effects of chronic alendronate (1 mg/kg/day) on depression and anxiety in an experimental animal model of menopause.

METHODS

Female Wistar rats were ovariectomized or sham operated at 6-7 months of age. Two weeks after surgery, rats were randomized into four treatment (24 consecutive weeks) groups: (1) vehicle-treated SHAM group, (2) alendronate-treated SHAM group, (3) vehicle-treated ovariectomized group, and (4) alendronate-treated ovariectomized group. After treatment, we evaluated both depressive- and anxiety-like behavior through forced swimming test (FST) and open-field test (OF). Finally, the inverted screen test was used to assess the incapacitating effects of ovariectomy in rats.

RESULTS

We documented a significant and time-related increase in immobility times and in anxiety-like behavior in rats with ovariectomy in comparison to control sham group. Alendronate at 3 months, but not at 6 months, significantly decreased both immobility time and anxiety levels, but it significantly increased motor performance. Using the Pearson's test, we documented a significant correlation between behavior and motor performance.

CONCLUSION

Despite the apparent effects of alendronate on animal behavior, in our experiments, such effects seem to be mediated by an increase in motor performance.

Catalase influence in the regulation of coronary resistance by estrogen: joint action of nitric oxide and hydrogen peroxide

We tested the influence of estrogen on coronary resistance regulation by modulating nitric oxide (NO) and hydrogen peroxide (H2O2) levels in female rats. For this, estrogen levels were manipulated and the hearts were immediately excised and perfused at a constant flow using a Langendorff's apparatus. Higher estrogen levels were associated with a lower coronary resistance, increased nitric oxide bioavailability, and higher levels of H2O2. When oxide nitric synthase blockade by L-NAME was performed, no significant changes were found in coronary resistance of ovariectomized rats. Additionally, we found an inverse association between NO levels and catalase activity. Taken together, our data suggest that, in the absence of estrogen influence and, therefore, reduced NO bioavailability, coronary resistance regulation seems to be more dependent on the H2O2 that is maintained at low levels by increased catalase activity.

Oophorectomy hinders antioxidant adaptation promoted by swimming in Wistar rats

Oxidative stress is associated with postmenopause and is also responsible for various metabolic alterations. The redox imbalance observed during ovarian decline can be induced experimentally by bilateral ovariectomy in rats. In addition to hormone replacement, regular moderate physical exercise is indicated to prevent several common postmenopausal diseases. This study aimed to assess the effect of daily swimming on the antioxidant defense system of oophorectomized Wistar rats. Control and oophorectomized groups were submitted to 1 h of daily swimming for 90 days. Levels of lipid peroxidation and glutathione content and the activities of superoxide dismutase enzyme and glutathione peroxidase in erythrocytes, liver, and brain were assessed every 30 days. The control group exhibited lower lipoperoxidation that was associated with a significant increase in superoxide dismutase enzyme activity, glutathione peroxidase activity, and glutathione content in erythrocytes and liver; however, swimming did not cause changes in antioxidant parameters in the brain over time. The oophorectomized group showed no antioxidant adaptation to daily swimming and had greater oxidative damage in the liver and blood. Our results suggest that ovariectomy hinders antioxidant adaptation in Wistar rats submitted to daily swimming.

The effects of Sutaehwan-Gami on menopausal symptoms induced by ovariectomy in rats

Background

This study was undertaken to evaluate the beneficial effects of a modified prescription of Sutaehwan named Sutaehwan-Gami (SG), created by adding Rhizoma dioscoreae and Carthami semen to Sutaehwan, on menopausal symptoms.

Methods

To evaluate the estrogenic effect of SG, we first examined estrogen receptor (ER) activation by SG treatment in breast adenocarcinoma cells and confirmed the estrogenic effect of SG in vivo ovariectomized rats. The animals were randomized into four groups: Sham operated group (Sham), saline treated ovariectomized group (OVX), SG treated group (SG) and raloxifene treated group (RLX). Animals were provided with SG at a dose of 500 mg/kg bw/day and RLX at a dose of 5.4 mg/kg bw/day with standard rat pellets for 3 months.

Results

SG significantly increased ERα phosphorylation, and its downstream effectors, extracellular signal-regulated kinase (ERK) and protein kinase B (Akt) phosphorylation in breast adenocarcinoma cells. Treatment with SG reversed ovariectomy-induced uterine weight reduction and weight gain. Decreases in the levels of GOT and GPT were observed in the SG group. The significantly reduced E₂β level in OVX rats was raised by treatment with SG. Moreover, SG significantly increased the phosphorylation levels of ERK and Akt in the uterus.

Conclusion

Taken together, these data indicate that SG has phytoestrogen-like properties through ERK and Akt activation, implying that it could be protective and beneficial for the management of menopausal symptoms.

Increased cerebral oxidative damage and decreased antioxidant defenses in ovariectomized and sham-operated rats supplemented with vitamin A

Previous studies have linked oxidative stress with aging and aging-related processes, including menopause. Abnormalities in the redox state similar to those observed in menopausal women can be modeled experimentally with rat ovariectomy. The aim of the present study was to investigate the effects of vitamin A (retinol palmitate) supplementation (500 or 1,500 IU kg(-1) day(-1) for 30 days) on behavioral parameters and brain redox profile in ovariectomized (OVX) and sham-operated rats. Ovariectomy caused pronounced uterine atrophy and decreased locomotor/exploratory activity. Moreover, we found increased hypothalamic and frontal cortex superoxide dismutase/catalase (SOD/CAT) ratio and decreased hippocampal thiol content, accompanied by increased frontal cortex lipid oxidative damage (TBARS) in OVX rats. Vitamin A at 1,500 IUkg(-1) day(-1) decreased exploratory behavior and decreased total hippocampal thiol content in sham-operated rats, increased hippocampal SOD/CAT ratio and decreased total antioxidant potential in the hippocampus of both sham and OVX groups, and increased cortical TBARS levels in OVX rats. Thus, vitamin A may induce a pro-oxidant state in discrete brain regions of sham-operated and OVX rats. These results suggest some caution regarding the use of high doses of vitamin A supplementation during menopause.