Theoretical basis for the benefit of postmenopausal estrogen substitution

Oxidative stress: A common pathological state in a high-risk population for osteoporosis

Osteoporosis is becoming a major concern in the field of public health. The process of bone loss is insidious and does not directly induce obvious symptoms. Complications indicate an irreversible decrease in bone mass. The high-risk populations of osteoporosis, including postmenopausal women, elderly men, diabetic patients and obese individuals need regular bone mineral density testing and appropriate preventive treatment. However, the primary changes in these populations are different, increasing the difficulty of effective treatment of osteoporosis. Determining the core pathogenesis of osteoporosis helps improve the efficiency and efficacy of treatment among these populations. Oxidative stress is a common pathological state secondary to estrogen deficiency, aging, hyperglycemia and hyperlipemia. In this review, we divided oxidative stress into the direct effect of reactive oxygen species (ROS) and the reduction of antioxidant enzyme activity to discuss their roles in the development of osteoporosis. ROS initiated mitochondrial apoptotic signaling and suppressed osteogenic marker expression to weaken osteogenesis. MAPK and NF-κB signaling pathways mediated the positive effect of ROS on osteoclast differentiation. Antioxidant enzymes not only eliminate the negative effects of ROS, but also directly participate in the regulation of bone metabolism. Additionally, we also described the roles of proinflammatory factors and HIF-1α under the pathophysiological changes of inflammation and hypoxia, which provided a supplement of oxidative stress-induced osteoporosis. In conclusion, our review showed that oxidative stress was a common pathological state in a high-risk population for osteoporosis. Targeted oxidative stress treatment would greatly optimize the therapeutic schedule of various osteoporosis treatments.

Olfactory Exposure to β-Caryophyllene Increases Testosterone Levels in Women's Saliva

INTRODUCTION

From previous studies, we hypothesized that olfactory exposure to β-caryophyllene stimulates women's libido. However, Japan's sex culture is so closed that it is difficult to test this possibility without accumulating scientific evidence. Therefore, it is necessary to measure the concentration of sex-related hormones in saliva, an experimental technique that is relatively easy to obtain research permission, and to obtain a scientific basis to convince ethics committee reviewers.

AIM

The aim of this study is to investigate whether β-caryophyllene increases salivary testosterone concentrations associated with libido and vaginal sensation during intercourse in women.

METHODS

19 women in the follicular phase of the menstrual cycle participated in the study. The subjects then sat in front of the odor exposure device we had created. Each subject was exposed to dipropylene glycol for 20 minutes, followed by 3% β-caryophyllene for 20 minutes. Saliva was collected 4 times: before and after control exposure, and before and after β-caryophyllene exposure.

MAIN OUTCOME MEASURE

Salivary testosterone and estrogen concentrations were measured with a competition ELISA.

RESULTS

β-caryophyllene significantly increased the salivary concentration of testosterone (control vs β-caryophyllene; 0.97 ± 0.05 vs 1.13 ± 0.03, P = .00, 95% confidence interval of control: 0.84-1.09, 95% confidence interval of β-caryophyllene: 1.04-1.20) but not estrogen (control vs β-caryophyllene; 1.05 ± 0.03 vs 1.07 ± 0.04, P = .69, 95% confidence interval of control: 0.96-1.12, 95% confidence interval of β-caryophyllene: 0.98-1.15).

STRENGTHS & LIMITATIONS

The personal preferences of the subjects and the order of exposure may have affected the results.

CONCLUSION

β-caryophyllene may be a remedy with fewer side effects for women with decreased libido. We believe that β-caryophyllene may be a remedy for women with decreased libido. However, this hypothesis must be tested by further clinical studies. Wataru Tarumi, Kazuyuki Shinohara. Olfactory Exposure to β-Caryophyllene Increases Testosterone Levels in Women's Saliva. J Sex Med 2020;8:525-531.

Effects of different postmenopausal hormone therapy regimens on cerebral blood flow and cognitive functions

INTRODUCTION

The purpose of this study was to compare the effects of different postmenopausal hormone therapy regimens, namely conjugated equine estrogens (CEE), CEE plus medroxyprogesterone acetate (MPA), tibolone, and raloxifene on cerebral blood flow and cognitive functions.

METHODS

A total of 64 healthy postmenopausal women admitted to the Department of Obstetrics and Gynecology, Cumhuriyet University, Turkey were included in this study. Patients were divided into five groups with respect to the treatment protocols: CEE 0.625 mg/day (n=13); CEE 0.625 mg/day + MPA 2.5 mg/day (n=14); tibolone 2.5 mg/day (n=11); raloxifene 60 mg/day (n=9); and control (n=17). The CEE group included only women with surgical menopause. Those who were on hormonal therapy, who had previously used hormonal therapy, who had neurological disorders, or who did not accept the longterm follow-up were excluded from the study. Demographic and clinic characteristics were recorded. Before starting the therapy regimens, cerebral blood flow was evaluated by internal carotid artery and middle cerebral artery peak systolic velocity, and pulsatility index measurements via Doppler ultrasonography. Cognitive functions were evaluated by the Standardized Mini-Mental Test. The mean follow-up period was 10.9+/-2.4 months, ranging between 8 and 16 months. After the follow-up period, the cerebral blood flow, and cognitive function of each woman was re-evaluated.

RESULTS

Demographic and clinical characteristics of the women were not significantly different between the study groups (P>0.05). There were no significant differences between the pretreatment and posttreatment values for cerebral blood flow indices and cognitive function scores in any of the study groups (P>0.05).

CONCLUSION

Different postmenopausal hormone therapy regimens have not revealed any significant effects on either cerebral blood flow or cognitive function.

Endogenous estrogen levels affect sexual function in elderly post-menopausal women

OBJECTIVE

The objective of this study was to determine if there is an association between endogenous serum concentration of estradiol (E2) and changes in sexual function in post-menopausal women over 3 years.

METHODS

Sexually active women (N = 345, mean = 65 years) who participated in the multiple outcomes of raloxifene evaluation trial (MORE) had endogenous E2 levels measured at baseline. All women completed the sexual history questionnaire at baseline and 3 years later. We assessed sexual function (desire, activity, feelings/experiences and sexual problems) among these women by endogenous E2 level (<20 pmol/l or > or =20 pmol/l).

RESULTS

At baseline, women with E2 levels <20 pmol/l had significantly greater discomfort and inability to relax compared with women with E2 > or =20 pmol/l (P < 0.05 for all). After 3 years, women with E2 > or =20 pmol/l had significantly less decline in sexual enjoyment (P < 0.02), satisfaction (P < 0.02), sexual comfort (P < 0.05) and sexual feelings summary score (P = 0.001), when compared with women who had E2 levels <20 pmol/l.

CONCLUSIONS

Endogenous E2 levels are important predictors of change in sexual function in elderly women who are sexually active. However, this result needs to be proven in a study with a bigger sample size of sexually active women, who present with changes in sexual function over several years. Also, future investigations are needed to assess the effects of other endogenous hormones on sexual function in elderly women.

Hormones and Supplements: Do They Work?: Use of Growth Hormone for Prevention or Treatment of Effects of Aging

Decreases in growth hormone (GH) and insulin-like growth factor-I, estrogen deficiency in women, diminished testosterone in men, and loss of lean body mass, increased fat, and other changes consistent with hormone deficiencies occur during aging. Treatment of nonelderly GH-deficient adults with recombinant human GH (rhGH) improves body composition, muscle strength, physical function, and bone density, and reduces blood cholesterol and cardiovascular disease risk, but is often accompanied by carpal tunnel syndrome, peripheral edema, joint pain and swelling, gynecomastia, glucose intolerance, and possibly increased cancer risk. Reports that rhGH augments lean body mass and reduces body fat in aged individuals increased use of rhGH to delay aging effects. However, clinically significant functional benefits, prolongation of youth, and life extension have not been demonstrated. Moreover, marketing of rhGH and other hormone supplements largely ignores adverse effects. Until more research has better defined the risk/benefit relationships, treatment of elderly individuals with rhGH should be confined to controlled research studies.

The effects of growth hormone and sex steroid on lean body mass, fat mass, muscle strength, cardiovascular endurance and adverse events in healthy elderly women and men

Decreases in growth hormone (GH) and insulin-like growth factor I occur with age, in addition to oestrogen deficiency in women and a reduction in the levels of testosterone in men. These age-related hormonal changes may contribute to reductions in lean body mass, muscle strength and cardiac endurance, which can be partially reversed in elderly people with GH treatment, and testosterone supplements and oestrogen/progestin hormone replacement therapy in men and women, respectively. These treatments are, however, thought to have potentially serious adverse effects. We conducted a study to evaluate the separate and interactive effects of GH and sex steroids on body composition, muscle strength and cardiac endurance as well as the rate of adverse events in healthy elderly people. The results of the study showed that although there were beneficial effects with GH and sex steroid treatment, a high percentage of adverse effects occurred after 26 weeks of treatment, demonstrating a need for more research on the safety of hormonal therapy in the elderly population.

Alpha and beta estradiol protect neuronal but not native PC12 cells from paraquat-induced oxidative stress

Oxidative stress is currently considered a mediator of cell death in several neurodegenerative diseases. Notably, it may play an important role in the degeneration of dopamine neurons of the substantia nigra in Parkinson's disease. We examined the effect of a strong oxidant, the herbicide paraquat, on cell distress using native and neuronal pheochromocytoma PC12 cells. Paraquat administration for 8 hours induced a significant cellular death in both native and in neuronal PC12 cells. Since the anti-oxidant properties of estrogens may promote neuroprotection in vitro and in vivo, we then investigated the ability of estradiol stereoisomers, 17alpha-estradiol and 17- beta-estradiol, to rescue PC12 cells submitted to paraquat-induced oxidative stress. Our results show a protective effect of both estradiol stereoisomers in neuronal PC12 cells treated with paraquat, whereas this effect could not be observed in native PC12 cells. We also demonstrate that estrogen receptor beta protein expression is modulated by paraquat administration in native PC12 cells, while paraquat does not change estrogen receptor beta ?expression in neuronal PC12 cells. Paraquat also decreases estrogen receptor alpha in neuronal PC12 cells, thus suggesting new routes for paraquat to collapse cellular metabolism. Besides, the oxidation of dihydrodhodamine-123 into fluorescent rhodamine in the presence of paraquat but not in presence of paraquat and 17 alpha-estradiol or 17 beta-estradiol, sustain a possible direct scavenging role of both estradiol stereoisomers.

Effects of estradiol, phytoestrogens, and Ginkgo biloba extracts against 1-methyl-4-phenyl-pyridine-induced oxidative stress

Oxidative stress has been recently considered as a mediator of nerve cell death in several neurodegenerative diseases. We studied the effect of the parkinsonism-inducing toxine 1-methyl-4-phenyl-pyridine (MPP+) on several parameters of cell distress using native and neuronal PC12 cells. Then, since estrogens have been reported to prevent neuronal degeneration caused by oxidative damage, we investigated the ability of 17beta- estradiol (E2); two Ginkgo biloba extracts, EGb 761 and Cp 202; as well as two flavonoids, quercetin and kaempferol, to rescue PC12 cells submitted to MPP+- induced oxidative stress. Our results consistently show that both Ginkgo biloba extracts could prevent cell death in native and neuronal PC12 cells, while in neuronal PC12 cells also quercetin and E2 could reverse MPP+ neurotoxic effet. Western blot analysis demonstrated that MPP+ injuries might modulate dopamine transporter (DAT) protein expression but not estrogen receptor beta (ERbeta) protein expression. EGb 761 and Cp 202 also modulate DAT and ERbeta protein expression in neuronal cells. From these studies, we outline the importance of testing estrogen-like plant-derived molecules as potent antioxidants and examine their effect on protein expression.

Female sexual dysfunction in postmenopausal women: systematic review of placebo-controlled trials

OBJECTIVE

This systematic review includes all randomized and placebo-controlled trials (RCTs) of treatment for female sexual dysfunction (FSD) in postmenopausal women published since 1990.

STUDY DESIGN

Electronic database and manual bibliography searches were conducted to identify all relevant publications.

RESULTS

Only six RCTs have been done to assess the effects of different therapies on sexual function in postmenopausal women: one with sildenafil citrate (Viagra), three with hormone replacement therapy, and two with tibolone.

CONCLUSIONS

In women with FSD, many treatments that are used in practice are not supported by adequate evidence. Although an improvement of sexual function was reported with tibolone and the combination of estrogen-androgen therapy, it still remains unclear which groups of postmenopausal women with FSD would benefit most from these therapies. The adverse effects of testosterone replacement therapy should be assessed against the effects of placebo in RCTs with larger sample sizes and longer duration.

Tyrosine kinase activity of nerve growth factor and estrogen in embryonic septal neurons cultured from the rat

Alzheimer's disease (AD) is a neurodegenerative disease characterized by dementia, senile plaques, fibrillary tangles, and a reduction of cholinergic neurons in the septal nucleus of the brain. Nerve growth factor (NGF) and estrogen were studied to observe effects on tyrosine kinase activity in septal neurons. The time course of tyrosine kinase activation and number of cells in which tyrosine kinase was activated were measured. Tissue from embryonic day 16 rats was microdissected and the septal neurons obtained were treated with estrogen (10 microM) or NGF (100 ng/mL) at intervals of 1, 2, 3, 4, 5, or 10 min. Immunostaining for phosphotyrosine revealed that cells treated with NGF showed an increase in phosphotyrosine activity within 2-4 min followed by a decline to control levels of enzyme activity. Treatment with estrogen led to an increase in phosphotyrosine immunostaining within 2-3 min followed by a decline to control levels. This time course suggests a mechanism for estrogen activity other than the traditional method involving binding to nuclear receptors followed by protein synthesis.

Neuroprotective effect of estradiol and phytoestrogens on MPP+-induced cytotoxicity in neuronal PC12 cells

A large body of experimental evidence supports a role for oxidative stress as a mediator of nerve cell death in Parkinson's disease. To better understand the cellular insult of oxidative stress on dopaminergic neurons, we studied the cytotoxic effect of the 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) metabolite, 1-methyl-4-phenyl pyridium (MPP(+)), on several parameters of cell distress using neuronal PC12 cells. We also measured the level of protein expression for the dopamine transporter and the estrogen receptors alpha and beta. Since estrogens have been reported to prevent neuronal degeneration caused by increased oxidative burden, we investigated the ability of 17beta-estradiol, the stereoisomer 17alpha-estradiol, and several phytoestrogens to rescue neuronal PC12 cells submitted to MPP(+)-induced cytotoxicity. Our results consistently show a protective effect of 17alpha-estradiol, 17beta-estradiol and certain phytoestrogens such as quercetin and resveratrol, in neuronal PC12 cells treated with MPP(+). In our cellular paradigm, phytoestrogens coumestrol, genistein, and kaempferol did not revert MPP(+)-induced cellular death. By Western blot, we demonstrated that administration of MPP(+) alone decrease dopamine transporter expression, while treatments with MPP(+) together with 17alpha-estradiol, 17beta-estradiol, quercetin, or resveratrol could restore dopamine transporter protein expression to control levels. Moreover, the same treatments did not modulate alpha estrogen receptor or beta estrogen receptor expression. By these studies, we aim to provide more evidence for the involvement of phytoestrogens in the process of neuroprotection and to test our hypothesis that some of these compounds may act as neuroprotective molecules and have a lesser hormonal effect than estrogens.

The physiology, medical management and oral implications of menopause

BACKGROUND

Approximately 36 million women in the United States are in the postmenopausal phase of life. The vast majority of these women experienced spontaneous cessation of menses between the ages of 47 and 55 years when the production of estrogen decreased because of an inadequate number of functioning follicles within their ovaries. Fewer women entered menopause after surgical removal of both ovaries. This procedure usually is performed prophylactically to prevent ovarian cancer in conjunction with a hysterectomy, which is required to treat abnormal bleeding, endometriosis or pelvic inflammatory disease. The physiological changes associated with spontaneous or surgical menopause cause some women to experience uncomfortable symptoms such as hot flashes, night sweats and vaginal dryness. In addition, estrogen deprivation arising from menopause in association with age-related factors disproportionately increases the risk of developing cardiovascular disease (that is, myocardial infarct, stroke), osteoporosis, Alzheimer's disease and oral disease. Hormone replacement therapy, or HRT (estrogen or estrogen and progestin), often is prescribed on a short-term basis to alleviate the uncomfortable symptoms associated with estrogen deficiency and on a long-term basis to prevent some of the chronic illnesses common to postmenopausal women.

CONCLUSIONS

Dentists who treat women entering menopause need to consider the stressful phase of life their patients are experiencing. Clinical findings of postmenopausal problems on dental examination may include a paucity of saliva, increased dental caries, dysesthesia, taste alterations, atrophic gingivitis, periodontitis and osteoporotic jaws unsuitable for conventional prosthetic devices or dental implants. Panoramic dental radiographs may reveal calcified carotid artery atheromas.

CLINICAL IMPLICATIONS

Dentists have an opportunity to refer women who are not under the care of a gynecologist for an evaluation to determine the appropriateness of HRT for its systemic and oral health benefits.

Estrogen replacement therapy for the potential treatment or prevention of Alzheimer's disease

Alzheimer's disease (AD) is an irreversible, progressive brain disorder that occurs gradually and results in memory loss, behavior and personality changes, and a decline in cognitive abilities. Although basic biological data suggest that estrogen may have neuroprotective and neuroenhancing functions, a number of studies have produced conflicting findings on the use of estrogen for maintaining cognitive function in older people. This review summarizes clinical studies that have examined the effects of estrogen in women with AD.

Fluctuations in spatial recognition memory across the menstrual cycle in female rhesus monkeys

Findings are inconsistent regarding whether women's cognitive performance fluctuates across phases of the menstrual cycle, but differences in methodology and the use of reported cycle phase rather than precise hormonal measures may underlie these disparities. Studies in monkeys may help resolve these discrepant findings, since hormonal status can be reliably determined. We tested four young (5-7 years old) female rhesus monkeys daily during one entire menstrual cycle on three cognitive tasks displayed on a computerized touch-screen system: a Matching to Sample task with a 30 s delay (MTS-30s), a Matching to Sample task without delay (MTS-no delay) and the spatial condition of the Delayed Recognition Span Test (spatial-DRST). Blood samples were collected at specific time intervals throughout the cycle and assayed for estradiol and progesterone in order to identify hormonal status. There was a nonsignificant trend for the MTS-30s scores to be better during the follicular and luteal phases, when estradiol levels were low, than during the peri-ovulatory phase, when estradiol levels were at their highest. MTS-no delay performance did not vary as a function of hormonal status. Spatial-DRST scores were significantly better during the follicular and luteal phases than during the peri-ovulatory phase of the cycle. These data in the female rhesus monkey support the hypothesis that spatial memory performance is sensitive to estradiol variations across the menstrual cycle, with better performance associated with low estradiol levels.

Comparison of soft tissue body composition in postmenopausal women with or without hormone replacement therapy considering the influence of reproductive history and lifestyle

OBJECTIVES

To examine long-term effects of at least 5 years' conventional hormone replacement therapy (HRT), reproductive history and lifestyle on fat mass and muscle mass in postmenopausal women.

RESEARCH DESIGN AND METHODS

A cross-sectional retrospective approach was used, including 64 healthy women (56-69 years, mean age 63.4 years). Hormone users were compared with age-matched non-users with respect to (a) type of HRT used (oestrogen vs oestrogen plus gestagen vs no hormones), (b) categories of oestrogens used (oestradiol-based oestrogens vs conjugated equine oestrogens vs no oestrogens) and (c) categories of gestagens used (testosterone derivatives vs progesterone derivatives vs no gestagens). Data on hormone use, reproductive history (age at menarche, age at menopause, number of years postmenopausal, number of children) and lifestyle (physical activity level, alcohol consumption, smoking habits) were collected by questionnaires. Body composition was analysed by multiple-frequency bioelectrical impedance analysis, estimating fat mass, fat-free mass and body cell mass as absolute values (FM, FFM, BCM, respectively) and percentages of body weight (%FM, %FFM, %BCM).

RESULTS

Analysis of covariance, adjusting body composition variables for body mass index, showed that (a) unopposed oestrogen users, oestrogen plus gestagen users and non-users did not differ significantly in body composition variables, (b) users of oestradiol-based oestrogens had significantly more BCM than oestrogen abstainers (p < 0.05), (c) users of testosterone-based gestagens had more BCM than gestagen abstainers (p = 0.05). Stepwise multiple regression analyses, including HRT-related, reproductive and lifestyle variables, indicated that the duration of HRT (p < 0.05) and physical activity level (p = 0.01) were significant positive predictors of %BCM, whereas the number of children significantly positively predicted FM and %FM (each p < 0.05). No significant associations between fat-free mass and HRT were found.

CONCLUSIONS

The results suggest that conventional doses of oestrogens and gestagens used in HRT might be a factor in preserving muscle mass after long-term administration. It is recommended that BCM is used instead of FFM as an indicator of muscle mass. Studies relating muscle mass to HRT in postmenopausal women should consider physical activity as a possible confounding variable.