Effects Of Exogenous Melatonin On Sleep And Circadian Rhythms In Women With Premenstrual Dysphoric Disorder

Overexpression of oHIOMT results in various morphological, anatomical, physiological and molecular changes in switchgrass

Introduction

Melatonin (N-acetyl-5-methoxytryptamine) is a molecule implicated in multiple biological functions, but exerts contrasting effects on plants owing to concentration differences. Hydroxyindole O-methyltransferase (HIOMT), which catalyzes the last step of melatonin synthesis, plays a crucial role in this context.

Methods

Transgenic switchgrass overexpressing oHIOMT with different melatonin levels displayed distinct morphological changes in a concentration-dependent manner. In this study, we divided the transgenic switchgrass into two groups: melatonin-moderate transgenic (MMT) plants and melatonin-rich transgenic (MRT) plants. To determine the concentration-dependent effect of melatonin on switchgrass growth and stress resistance, we conducted comparative morphological, physiological, omics and molecular analyses between MMT, MRT and wild-type (WT) plants.

Results

We found that oHIOMT overexpression, with moderate melatonin levels, was crucial in regulating switchgrass growth through changes in cell size rather than cell number. Moderate levels of melatonin were vital in regulating carbon fixation, stomatal development and chlorophyll metabolism. Regarding salt tolerance, melatonin with moderate levels activated numerous defense (e.g. morphological characteristics, anatomical structure, antioxidant enzymatic properties, non-enzymatic capacity and Na+/K+ homeostasis). Additionally, moderate levels of oHIOMT overexpression were sufficient to increase lignin content and alter monolignol compositions with an increase in the S/G lignin ratio.

Discussion

Taken together, oHIOMT overexpression in switchgrass with different melatonin levels resulted in morphological, anatomical, physiological and molecular changes in a concentration-dependent manner, which characterized by stimulation at low doses and inhibition at high doses. Our study presents new ideas and clues for further research on the mechanisms of the concentration-dependent effect of melatonin.

The Menstrual Cycle and Sleep

Aspects of sleep change across the menstrual cycle in some women. Poorer sleep quality in the premenstrual phase and menstruation is common in women with premenstrual symptoms or painful menstrual cramps. Although objective sleep continuity remains unchanged across the regular, asymptomatic menstrual cycle, activity in the sleep electroencephalogram varies, with a prominent increase in sleep spindle activity in the postovulatory luteal phase, when progesterone is present, relative to the follicular phase. Menstrual cycle phase, reproductive stage, and menstrual-related disorders should be considered when assessing women's sleep complaints.

Recent Progress in Long-Term Sleep Monitoring Technology

Sleep is an essential physiological activity, accounting for about one-third of our lives, which significantly impacts our memory, mood, health, and children's growth. Especially after the COVID-19 epidemic, sleep health issues have attracted more attention. In recent years, with the development of wearable electronic devices, there have been more and more studies, products, or solutions related to sleep monitoring. Many mature technologies, such as polysomnography, have been applied to clinical practice. However, it is urgent to develop wearable or non-contacting electronic devices suitable for household continuous sleep monitoring. This paper first introduces the basic knowledge of sleep and the significance of sleep monitoring. Then, according to the types of physiological signals monitored, this paper describes the research progress of bioelectrical signals, biomechanical signals, and biochemical signals used for sleep monitoring. However, it is not ideal to monitor the sleep quality for the whole night based on only one signal. Therefore, this paper reviews the research on multi-signal monitoring and introduces systematic sleep monitoring schemes. Finally, a conclusion and discussion of sleep monitoring are presented to propose potential future directions and prospects for sleep monitoring.

The Effect of Zinc Supplementation on the Improvement of Premenstrual Symptoms in Female University Students: a Randomized Clinical Trial Study

Zinc is an essential microelement that plays many important functions in the body. It is crucial for the regulation of cell growth, hormone release, immunological response, and reproduction. Thus, this trial aimed to evaluate the effects of zinc supplementation in comparison with placebo on the improvement of premenstrual symptoms in female university students. This triple-masked, randomized, placebo-controlled, parallel trial was conducted among 69 female students aged 18-35 with premenstrual syndrome that living in dormitories of Hamadan University of Medical Sciences, in west of Iran. Participants were randomly assigned to two groups of equal number; one group received 220 mg of elemental zinc (n = 33) and the other group received placebo (n = 36) on a regular daily for 24 weeks. The premenstrual syndrome was assessed by Premenstrual Symptoms Screening Tool-Adolescent (PSST-A) questionnaire for all participants. Chi-square and t-student tests were used to compare the percentage or mean of parameters between two groups. All statistical analysis conducted by SPSS version 16. The mean age in the intervention group was 25.64 [Formula: see text] 0.53 years, and in the control group was 24.38 [Formula: see text] 0.51 years (P = 0.087). After 24 weeks of intervention, PMS physical and psychological symptoms such as anger, anxiety, depressed mood, overeating, breast tenderness, headaches, muscle pain, bloating, and weight gain significantly decreased in zinc group compared to placebo group (P < 0.001). We observed a significant increase in relationship with friends, classmates, and coworkers (p = 0.003) after 24 weeks of intervention with zinc compared to placebo. In conclusion, zinc, as a simple and inexpensive treatment, was associated with improvement of PMS symptoms. Given that this is among the first studies to evaluate the effect of zinc supplementation on PMS, additional studies are warranted to confirm these findings.

Melatonin for premenstrual syndrome: A potential remedy but not ready

Premenstrual syndrome (PMS), a recurrent and moderate disorder that occurs during the luteal phase of the menstrual cycle and quickly resolves after menstruation, is characterized by somatic and emotional discomfort that can be severe enough to impair daily activities. Current therapeutic drugs for PMS such as selective serotonin reuptake inhibitors are not very satisfying. As a critical pineal hormone, melatonin has increasingly been suggested to modulate PMS symptoms. In this review, we update the latest progress on PMS-induced sleep disturbance, mood changes, and cognitive impairment and provide possible pathways by which melatonin attenuates these symptoms. Moreover, we focus on the role of melatonin in PMS molecular mechanisms. Herein, we show that melatonin can regulate ovarian estrogen and progesterone, of which cyclic fluctuations contribute to PMS pathogenesis. Melatonin also modulates gamma-aminobutyric acid and the brain-derived neurotrophic factor system in PMS. Interpreting the role of melatonin in PMS is not only informative to clarify PMS etiology but also instructive to melatonin and its receptor agonist application to promote female health. As a safe interaction, melatonin treatment can be effective in alleviating symptoms of PMS. However, symptoms such as sleep disturbance, depressive mood, cognitive impairment are not specific and can be easily misdiagnosed. Connections between melatonin receptor, ovarian steroid dysfunction, and PMS are not consistent among past studies. Before final conclusions are drawn, more well-organized and rigorous studies are recommended.