Melatonin, Clock Genes, and Mammalian Reproduction: What Is the Link?

Physiological processes and behaviors in many mammals are rhythmic. Recently there has been increasing interest in the role of circadian rhythmicity in the control of reproductive function. The circadian rhythm of the pineal hormone melatonin plays a role in synchronizing the reproductive responses of animals to environmental light conditions. There is some evidence that melatonin may have a role in the biological regulation of circadian rhythms and reproduction in humans. Moreover, circadian rhythms and clock genes appear to be involved in optimal reproductive performance. These rhythms are controlled by an endogenous molecular clock within the suprachiasmatic nucleus (SCN) in the hypothalamus, which is entrained by the light/dark cycle. The SCN synchronizes multiple subsidiary oscillators (clock genes) existing in various tissues throughout the body. The basis for maintaining the circadian rhythm is a molecular clock consisting of transcriptional/translational feedback loops. Circadian rhythms and clock genes appear to be involved in optimal reproductive performance. This mini review summarizes the current knowledge regarding the interrelationships between melatonin and the endogenous molecular clocks and their involvement in reproductive physiology (e.g., ovulation) and pathophysiology (e.g., polycystic ovarian syndrome).

Schizophrenia and Sex Hormones: What Is the Link?

The involvement of gonadal hormones in the pathogenesis of schizophrenia has long been suspected because the psychosis differs in women and men and the illness first makes its appearance shortly after puberty. Changes in sex hormones have been linked with increased vulnerability to mood disorders in women, while testosterone have been associated with increased sexual drive and aggressiveness in men as well as women. Some studies have found abnormal levels of estrogens and testosterone in schizophrenia patients, but the results have been inconsistent and sometimes attributed to the hyperprolactinemia effect of antipsychotics, which may interfere with sex hormones production. The purpose of this review is to present the current knowledge on the link between blood levels of sex-hormones in women during the various stages of the female reproductive life (i.e. puberty, menstrual cycle, pregnancy, contraception, and menopause) and the course of schizophrenia. We also attempt to optimize the clinical approach to women with schizophrenia at these different stages.

A Placebo-Controlled Double-Blind Randomized Trial with Individualized Homeopathic Treatment Using a Symptom Cluster Approach in Women with Premenstrual Syndrome.

BACKGROUND: In a double-blind placebo-controlled randomized trial with parallel groups, the efficacy of individually prescribed homeopathic medicines was evaluated in women with premenstrual syndrome (PMS). METHODS: In an outpatient department of a university clinic in Jerusalem, Israel (1996-1999), women with PMS, aged 18 to 50 years, entered a 2-month screening phase with prospective daily recording of premenstrual symptoms by the Menstrual Distress Questionnaire (MDQ). They were included after being diagnosed with PMS. A reproducible treatment protocol was used: women received a homeopathic prescription based on symptom clusters identified in a questionnaire. The symptoms were verified during a complementary, structured, interview. Only women whose symptoms matched the symptom profile of one of 14 pre-selected homeopathic medicines were included. Each participant was administered active medicine or placebo via random allocation. Primary outcome measures were differences in changes in mean daily premenstrual symptom (PM) scores by the MDQ. Analysis was by intention-to-treat. RESULTS: A total of 105 women were included: 49 were randomized to active medicine and 56 to placebo. Forty-three women in the active medicine group and 53 in the placebo group received the allocated intervention with at least one follow-up measurement and their data were analyzed. Significantly greater improvement of mean PM scores was measured in the active medicine group (0.443 [standard deviation, SD, 0.32] to 0.287 [SD, 0.20]) compared to placebo (0.426 [SD, 0.34] to 0.340 [SD, 0.39]); p = 0.043. CONCLUSIONS: Individually prescribed homeopathic medicines were associated with significantly greater improvement of PM scores in women with PMS, compared to placebo. Replication, with larger sample size and other refinements, is recommended to confirm the efficacy of this treatment in other settings.

Is the aging human ovary still ticking?: Expression of clock-genes in luteinized granulosa cells of young and older women.

BACKGROUND: It has been shown - mostly in animal models - that circadian clock genes are expressed in granulosa cells and in corpora luteum and might be essential for the ovulatory process and steroidogenesis. OBJECTIVE: We sought to investigate which circadian clock genes exist in human granulosa cells and whether their expression and activity decrease during aging of the ovary. STUDY DESIGN: Human luteinized granulosa cells were isolated from young (age 18-33) and older (age 39-45) patients who underwent in-vitro fertilization treatment. Levels of clock genes expression were measured in these cells 36 h after human chorionic gonadotropin stimulation. METHODS: Human luteinized granulosa cells were isolated from follicular fluid during oocyte retrieval. The mRNA expression levels of the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2 were analyzed by quantitative polymerase chain reaction. RESULTS: We found that the circadian genes CRY1, CRY2, PER1, PER2, CLOCK, ARNTL, ARNTL2, and NPAS2, are expressed in cultured human luteinized granulosa cells. Among these genes, there was a general trend of decreased expression in cells from older women but it reached statistical significance only for PER1 and CLOCK genes (fold change of 0.27 ± 0.14; p = 0.03 and 0.29 ± 0.16; p = 0.05, respectively). CONCLUSIONS: This preliminary report indicates that molecular circadian clock genes exist in human luteinized granulosa cells. There is a decreased expression of some of these genes in older women. This decline may partially explain the decreased fertility and steroidogenesis of reproductive aging.

Melatonin and health: an umbrella review of health outcomes and biological mechanisms of action.

BACKGROUND: Our aims were to evaluate critically the evidence from systematic reviews as well as narrative reviews of the effects of melatonin (MLT) on health and to identify the potential mechanisms of action involved. METHODS: An umbrella review of the evidence across systematic reviews and narrative reviews of endogenous and exogenous (supplementation) MLT was undertaken. The Oxman checklist for assessing the methodological quality of the included systematic reviews was utilised. The following databases were searched: MEDLINE, EMBASE, Web of Science, CENTRAL, PsycINFO and CINAHL. In addition, reference lists were screened. We included reviews of the effects of MLT on any type of health-related outcome measure. RESULTS: Altogether, 195 reviews met the inclusion criteria. Most were of low methodological quality (mean -4.5, standard deviation 6.7). Of those, 164 did not pool the data and were synthesised narratively (qualitatively) whereas the remaining 31 used meta-analytic techniques and were synthesised quantitatively. Seven meta-analyses were significant with P values less than 0.001 under the random-effects model. These pertained to sleep latency, pre-operative anxiety, prevention of agitation and risk of breast cancer. CONCLUSIONS: There is an abundance of reviews evaluating the effects of exogenous and endogenous MLT on health. In general, MLT has been shown to be associated with a wide variety of health outcomes in clinically and methodologically heterogeneous populations. Many reviews stressed the need for more high-quality randomised clinical trials to reduce the existing uncertainties.

Low-Level Laser Therapy for the Treatment of Provoked Vestibulodynia-A Randomized, Placebo-Controlled Pilot Trial.

BACKGROUND: Low-level laser therapy (LLLT) is an emerging medical technology in which non-thermal laser irradiation is applied to treat pain. Because LLLT has been found effective in treating various pain syndromes without known side effects, we conducted a study evaluating the effect of LLLT on provoked vestibulodynia (PVD), a complex sexual pain disorder characterized by pain confined to the vulvar vestibule in response to contact or pressure. AIM: To investigate the effectiveness of LLLT for PVD in a randomized, placebo-controlled, double-blinded trial. METHODS: Patients with PVD were randomly assigned to receive treatment with LLLT or sham treatment. Patients were treated twice weekly for 6 weeks, for a total of 12 LLLT or placebo sessions. Patients who showed improvement after LLLT were followed for 1 year by clinical pain report and Q-tip examination. OUTCOMES: Change in pain scores obtained in response to the Q-tip test, clinical pain report, visual analog scale score, pain with tampon insertion, daily pain intensity, intercourse pain intensity, frequency of intercourse, and a battery of quality-of-life measures. RESULTS: Thirty-four patients with PVD participated, 18 received LLLT and 16 received placebo. In the clinical pain report at study completion, 14 of 18 patients (78%) receiving LLLT reported improvement compared with 7 of 16 (44%) in the placebo group (P = .042). This effect was not apparent in other outcome measurements. None of the patients reported side effects during the study. At 1-year follow-up, eight patients (57%) reported lasting improvement. CLINICAL IMPLICATIONS: Larger studies with various treatment protocols are needed to define which patients can benefit from LLLT therapy. STRENGTHS AND LIMITATIONS: Strengths include a placebo-controlled, double-blinded design, measurement of a large number of multidimensional end points, and a follow-up period of 1 year. Limitations include the small number of patients recruited, no improvement in measurable parameters, a high improvement rate in the placebo group, the absence of use of validated questionnaires, and the lack of evaluation of psychological and interpersonal factors that might have influenced the results. CONCLUSIONS: Given the results of this pilot study, LLLT cannot currently be recommended as a treatment for PVD. Further studies with a larger population, various treatment protocols, and evaluation of LLLT in different subgroups of PVD are needed to define which patients can benefit from this therapy. Lev-Sagie A, Kopitman A, Brzezinski A. Low-Level Laser Therapy for the Treatment of Provoked Vestibulodynia-A Randomized, Placebo-Controlled Pilot Trial. J Sex Med 2017;14:1403-1411.

Sleep, Melatonin, and the Menopausal Transition: What Are the Links?

The pineal hormone Melatonin plays an important role in the regulation of the circadian sleep/wake cycle, mood, and perhaps immune functions, carcinogensis and reproduction. The human circadian rhythm of melatonin release from the pineal gland is tightly synchronized with the habitual hours of sleep. Peri- and postmenopausal women often complain of difficulties initiating and/or maintaining sleep, with frequent nocturnal and early morning awakenings. In this review we discuss the pathophysiology of melatonin function as it relates to sleep disorders in menopausal women, highlighting the potential use of exogenous melatonin during the menopausal transition and beyond.

Treating schizophrenia during menopause.

OBJECTIVE: The aim of this review is to examine three questions: What are the risks and benefits of treating women with schizophrenia with hormone therapy (HT) at menopause? Should the antipsychotic regimen be changed at menopause? Do early- and late-onset women with schizophrenia respond differently to HT at menopause? METHODS: MEDLINE databases for the years 1990 to 2016 were searched using the following interactive terms: schizophrenia, gender, menopause, estrogen, and hormones. The selected articles (62 out of 800 abstracts) were chosen on the basis of their applicability to the objectives of this targeted narrative review. RESULTS: HT during the perimenopause in women with schizophrenia ameliorates psychotic and cognitive symptoms, and may also help affective symptoms. Vasomotor, genitourinary, and sleep symptoms are also reduced. Depending on the woman's age and personal risk factors and antipsychotic side effects, the risk of breast cancer and cardiovascular disease may be increased. Antipsychotic types and doses may need to be adjusted at menopause, as may be the mode of administration. CONCLUSIONS: Both HT and changes in antipsychotic management should be considered for women with schizophrenia at menopause. The question about differences in response between early- and late-onset women cannot yet be answered.

The impact of financing of screening tests on utilization and outcomes: The case of amniocentesis.

We use a 1993 policy change in Israel's public healthcare system that lowered the eligibility age for amniocentesis to 35 to study the effects of financing of screening tests. Financing is found to have increased amniocentesis testing by about 35%. At ages above the eligibility threshold, utilization rates rose to roughly 33%, reflection nearly full takeup among prospective users of amniocentesis. Additionally, whereas below the age-35 threshold amniocentesis utilization rates increase with maternal age, this relation is muted above this age. Finally, no evidence is found that financing affects outcomes such as pregnancy terminations and births of children with Down syndrome. These results support the view that women above the eligibility threshold tend to refrain from acquiring inexpensive information about their degree of risk that absent the financing they would acquire, and instead, undergo the accurate and costly test regardless of additional information that noninvasive screening would provide.

Sleep Disorders in Postmenopausal Women.

One of the core symptoms of the menopausal transition is sleep disturbance. Peri-menopausal women often complain of difficulties initiating and/or maintaining sleep with frequent nocturnal and early morning awakenings. Factors that may play a role in this type of insomnia include vasomotor symptoms, changing reproductive hormone levels, circadian rhythm abnormalities, mood disorders, coexistent medical conditions, and lifestyle. Other common sleep problems in this age group, such as obstructive sleep apnea and restless leg syndrome, can also worsen the sleep quality. Exogenous melatonin use reportedly induces drowsiness and sleep and may ameliorate sleep disturbances, including the nocturnal awakenings associated with old age and the menopausal transition. Recently, more potent melatonin analogs (selective melatonin-1 (MT1) and melatonin-2 (MT2) receptor agonists) with prolonged effects and slow-release melatonin preparations have been developed. They were found effective in increasing total sleep time and sleep efficiency as well as in reducing sleep latency in insomnia patients. The purpose of this review is to give an overview on the changes in hormonal status to sleep problems among menopausal and postmenopausal women.

Regular exercise is the most significant lifestyle parameter associated with the severity of climacteric symptoms: a cross sectional study.

OBJECTIVE: To assess the association between demographic and lifestyle parameters and perceived severity of the climacteric syndrome in perimenopausal women. STUDY DESIGN: A cross-sectional study of 151 healthy women aged 45-55 years who attended the University Medical Center affiliated menopause clinics. The analysis was based on self completion of the Greene climacteric score, consisting of psychological, somatic/physical, sexual and vasomotor subscores. The Greene total score and subscores were the main outcomes of the study. RESULTS: Of all demographic, anthropometric and lifestyle parameters recorded, the correlates with reduced total Greene score were high-order maternity and regular physical exercise. Mothers of 3 or more children reported significantly lower total Greene score (18±12.8 vs. 22.1±8.1) (p=0.01) as well as lower psychological subscore (8.7±6.8 vs. 11.5±5.4) (p=0.01). Regular physical activity was also associated with significantly lower total Greene score (17.0±11.0 vs. 22.6±11.3) (p=0.01) and specifically lower psychological subscore (9.5±6.6 vs. 12.8±7.7) (p=0.03) and sexual subscore (1.1±0.99 vs. 1.61±1.05) (p=0.03). Linear regression models showed that regular exercise was the lifestyle parameter most significantly correlated with a lower total Greene score (p=0.006) independent of menopausal status. Of particular note, regular exercise was significantly correlated with lower psychological (p=0.006) and physical subscores (p=0.06). Moreover, the higher the frequency of exercise (both aerobic and non aerobic), the lower the severity of the climacteric symptoms reported, yet the vasomotor and sexual subscores remained unchanged. CONCLUSIONS: Regular exercise of at least 3 times a week was the most significant lifestyle parameter to be associated with the severity of climacteric symptoms.

Melatonin in antinociception: its therapeutic applications.

The intensity of pain sensation exhibits marked day and night variations. Since the intensity of pain perception is low during dark hours of the night when melatonin levels are high, this hormone has been implicated as one of the prime antinociceptive substances. A number of studies have examined the antinociceptive role of melatonin in acute, inflammatory and neuropathic pain animal models. It has been demonstrated that melatonin exerts antinociceptive actions by acting at both spinal cord and supraspinal levels. The mechanism of antinociceptive actions of melatonin involves opioid, benzodiazepine, α(1)- and α(2)-adrenergic, serotonergic and cholinergic receptors. Most importantly however, the involvement of MT(1)/MT(2) melatonergic receptors in the spinal cord has been well documented as an antinociceptive mechanism in a number of animal models of pain perception. Exogenous melatonin has been used effectively in the management of pain in medical conditions such as fibromyalgia, irritable bowel syndrome and migraine and cluster headache. Melatonin has been tried during surgical operating conditions and has been shown to enhance both preoperative and post-operative analgesia. The present review discusses the available evidence indicating that melatonin, acting through MT(1)/MT(2) melatonin receptors, plays an important role in the pathophysiological mechanism of pain.

Role of melatonin in mood disorders and the antidepressant effects of agomelatine.

INTRODUCTION: Disturbances of circadian rhythms and sleep play an important role in various types of mood disorders like major depressive disorder (MDD), bipolar depressive disorder (BPD) and seasonal affective disorder (SAD). Malfunctioning of the SCN-pineal-melatonin link has been suggested as the main cause for these disorders. As a rhythm-regulating factor and as a hormone involved in the regulation of sleep, melatonin is essential for the control of mood and behavior. AREAS COVERED: Melatonin's involvement in various mood disorders is reviewed based on studies undertaken in patients with MDD, BPD and SAD. The chemistry and metabolism of the newly introduced antidepressant, agomelatine, a MT1/MT2 melatonin receptor agonist and 5-HT2c antagonist in brain areas involved in mood regulation are also discussed. Its clinical role in mood regulation, agomelatine's efficacy, safety and tolerability are also reviewed. EXPERT OPINION: Agomelatine, a melatonergic antidepressant with a rapid onset of action, has been shown effective in various types of mood disorders (e.g., MDD, BPD, SAD). Some studies find it superior to other common antidepressants (SSRIs, SNRIs) that are in clinical use today. Agomelatine's efficacy, good tolerability and safety profile suggest that it may become a preferred antidepressant in the near future.

Melatonergic drugs for therapeutic use in insomnia and sleep disturbances of mood disorders.

Insomnia is common among elderly people and nearly 30 to 40% of the adult population also suffer from insomnia. Pharmacological treatment of insomnia include the use of benzodiazepine and non-benzodiazepine drugs like zolpidem, zaleplon, Zopiclone. Although these drugs improve sleep, their usage is also associated with number of adverse effects, Melatonin, the hormone secreted by the pineal gland of all animals and human beings has been used for treatment of insomnias, since the timing of its secretion in humans as well as in most of the animals coincides with the increase of nocturnal sleep propensity. Because of its short half life, melatonin slow release preparations were introduced for treatment of insomnia. Recently ramelteon, a selective MT1, MT2 receptor agonist with greater efficacy of action in treating insomnia has been used clinically and has been found effective in improving sleep quality, sleep efficacy and also in reducing the sleep onset time when compared to melatonin or slow melatonin preparations. The mechanism of action of ramelteon in improving sleep is discussed in the paper. Another melatonergic drug agomelatine besides acting on MT1/MT2 receptors also displays 5-HT2c antagonism and this drug has been found effective as a novel antidepressant for treating major depressive disorders. Agomelatine besides causing remission of depressive symptoms also improves sleep quality and efficiency. Other antidepressants depressants that are in clinical use today do not improve sleep. There are other melatonergic drugs like tasimelteon, 6-chloromelatonin. But ramelteon and agomelatine deserve special attention for treatment of insomnia and sleep disturbances associated with depressive disorders and have promising role for treatment of sleep disorders.

Melatonin and its analogs in insomnia and depression.

Benzodiazepine sedative-hypnotic drugs are widely used for the treatment of insomnia. Nevertheless, their adverse effects, such as next-day hangover, dependence and impairment of memory, make them unsuitable for long-term treatment. Melatonin has been used for improving sleep in patients with insomnia mainly because it does not cause hangover or show any addictive potential. However, there is a lack of consistency on its therapeutic value (partly because of its short half-life and the small quantities of melatonin employed). Thus, attention has been focused either on the development of more potent melatonin analogs with prolonged effects or on the design of slow release melatonin preparations. The MT(1) and MT(2) melatonergic receptor ramelteon was effective in increasing total sleep time and sleep efficiency, as well as in reducing sleep latency, in insomnia patients. The melatonergic antidepressant agomelatine, displaying potent MT(1) and MT(2) melatonergic agonism and relatively weak serotonin 5HT(2C) receptor antagonism, was found effective in the treatment of depressed patients. However, long-term safety studies are lacking for both melatonin agonists, particularly considering the pharmacological activity of their metabolites. In view of the higher binding affinities, longest half-life and relative higher potencies of the different melatonin agonists, studies using 2 or 3mg/day of melatonin are probably unsuitable to give appropriate comparison of the effects of the natural compound. Hence, clinical trials employing melatonin doses in the range of 50-100mg/day are warranted before the relative merits of the melatonin analogs versus melatonin can be settled.

Melatonin, immune function and cancer.

Melatonin is a natural substance ubiquitous in distribution and present in almost all species ranging from unicellular organisms to humans. In mammals, melatonin is synthesized not only in the pineal gland but also in many other parts of the body, including the eyes, bone marrow, gastrointestinal tract, skin and lymphocytes. Melatonin influences almost every cell and can be traced in membrane, cytoplasmic, mitochondrial and nuclear compartments of the cell. The decline in the production of melatonin with age has been suggested as one of the major contributors to immunosenescence and development of neoplastic diseases. Melatonin is a natural antioxidant with immunoenhancing properties. T-helper cells play an important role for protection against malignancy and melatonin has been shown to enhance T-helper cell response by releasing interleukin-2, interleukin-10 and interferon-γ. Melatonin is effective in suppressing neoplastic growth in a variety of tumors like melanoma, breast and prostate cancer, and ovarian and colorectal cancer. As an adjuvant therapy, melatonin can be beneficial in treating patients suffering from breast cancer, hepatocellular carcinoma or melanoma. In this paper, a brief review of recent patents on melatonin and cancer has also been presented.

Melatonin agonists in primary insomnia and depression-associated insomnia: are they superior to sedative-hypnotics?

Current pharmacological treatment of insomnia involves the use of sedative-hypnotic benzodiazepine and non-benzodiazepine drugs. Although benzodiazepines improve sleep, their multiple adverse effects hamper their application. Adverse effects include impairment of memory and cognitive functions, next-day hangover and dependence. Non-benzodiazepines are effective for initiating sleep but are not as effective as benzodiazepines for improving sleep quality or efficiency. Furthermore, their prolonged use produces adverse effects similar to those observed with benzodiazepines. Inasmuch as insomnia may be associated with decreased nocturnal melatonin, administration of melatonin is a strategy that has been increasingly used for treating insomnia. Melatonin can be effective for improving sleep quality without the adverse effects associated with hypnotic-sedatives. Ramelteon, a synthetic analog of melatonin which has a longer half life and a stronger affinity for MT1 and MT2 melatonergic receptors, has been reportedly effective for initiating and improving sleep in both adult and elderly insomniacs without showing hangover, dependence, or cognitive impairment. Insomnia is also a major complaint among patients suffering from depressive disorders and is often aggravated by conventional antidepressants especially the specific serotonin reuptake inhibitors. The novel antidepressant agomelatine, a dual action agent with affinity for melatonin MT1 and MT2 receptors and 5-HT2c antagonistic properties, constitutes a new approach to the treatment of major depressive disorders. Agomelatine ameliorates the symptoms of depression and improves the quality and efficiency of sleep. Taken together, the evidence indicates that MT1/MT2 receptor agonists like ramelteon or agomelatine may be valuable pharmacological tools for insomnia and for depression-associated insomnia.

High-order maternity may be a more significant determinant of quality of midlife than some of the climacteric symptoms.

OBJECTIVE: The aim of this study was to assess the impact of menopause, age, and women's symptoms and characteristics on quality of midlife. METHODS: This was a cross-sectional study of 151 healthy women aged 45 to 55 years attending university-affiliated menopause clinics. To obtain the data, a questionnaire designed by the investigators and based on the Greene Climacteric Scale and the Utian Menopause-Specific Quality of Life scale was self-completed by the participants. RESULTS: A significant gradual increase in the total Greene Climacteric Scale score was observed from premenopausal to perimenopausal and postmenopausal women (P = 0.02), specifically in the vasomotor and sexual subscores (P < 0.0001 and P = 0.001, respectively). In contrast, the total quality-of-life score remained stable in every specific aspect (occupation, health, emotion, and sex) throughout the menopausal transition (P = 0.8). A significant correlation was found between the psychological, somatic, and sexual Greene Climacteric Scale subscores and the Utian quality-of-life score (r = -0.46, P < 0.001; r = -0.29, P < 0.05; r = -0.28, P < 0.05, respectively), whereas the vasomotor subscore had no impact on midlife quality. The number of children was the only demographic factor that had a significant impact on the Utian score (P < 0.05) and to a higher extent than the climacteric syndrome. Hormone therapy equalizes the climacteric symptom profile of users to that of nonusers, yet both users and nonusers reported similar scores of midlife quality. CONCLUSIONS: Menopause-specific quality of life may be affected by both demographic and climacteric parameters. Menopausal symptoms, but not vasomotor symptoms, have a negative impact on midlife quality, yet to a lesser degree than does the number of children.