Co-administering Melatonin With an Estradiol-Progesterone Menopausal Hormone Therapy Represses Mammary Cancer Development in a Mouse Model of HER2-Positive Breast Cancer

Exploring Melatonin's Multifaceted Role in Polycystic Ovary Syndrome Management: A Comprehensive Review

Polycystic Ovary Syndrome (PCOS) is a complex endocrine disorder affecting a significant portion of the female population, characterized by hormonal imbalances, oxidative stress, sleep disturbances, and mood disorders. This review explores the multifaceted role of melatonin, a hormone primarily known for regulating circadian rhythms, in PCOS management. Melatonin's potential impact on hormonal balance, oxidative stress, sleep quality, and mood is comprehensively examined. It has been shown to enhance insulin sensitivity, regulate sex hormones, and influence gonadotropins, offering promise in addressing the intricate hormonal imbalances common in PCOS. As a potent antioxidant and anti-inflammatory agent, melatonin mitigates oxidative stress and its associated complications. Its role in improving sleep quality and mood can significantly enhance the psychological well-being and daily functioning of PCOS patients. We discuss the potential implications of melatonin as a complementary or adjunct therapy, alongside existing PCOS treatments, and its significance in improving the overall quality of life for individuals with this syndrome. While further research is needed, melatonin's multifaceted effects promise a brighter future for PCOS patients.

Melatonin Alleviates Ovariectomy-Induced Cardiovascular Inflammation in Sedentary or Exercised Rats by Upregulating SIRT1

We aimed to evaluate the impact of hormone replacement, melatonin, or exercise alone or their combination on oxidative damage and functional status of heart, brain, and aorta of ovariectomized (OVX) rats and to determine whether the signaling pathway is dependent on sirtuin-1 (SIRT1). Ovariectomized Sprague Dawley rats were orally given either a hormone replacement therapy (1 mg/kg/day,17β estradiol; HRT) or melatonin (4 mg/kg/day) or HRT + melatonin treatments or tap water, while each group was further divided into sedentary and exercise (30 min/5 days/week) groups. After the heart rate measurements and memory tests were performed, trunk blood was collected at the end of the 10th week to determine metabolic parameters in serum samples. Tissue samples of abdominal aorta, heart, and brain were taken for biochemical measurements and histopathological evaluation. Heart rates and memory performances of the OVX rats were not changed significantly by none of the applications. Melatonin treatment or its co-administration with HRT upregulated the expressions of IL-10 and SIRT1, reduced the expressions of IL-6 and TNF-α, and reduced DNA damage in the hearts and thoracic aortae of non-exercised rats. Co-administration of melatonin and HRT to exercised OVX rats reduced inflammatory response and upregulated SIRT1 expression in the aortic and cardiac tissues. The present study suggests that melatonin treatment, either alone or in combination with exercise and/or HRT, upregulates SIRT1 expression and alleviates oxidative injury and inflammation in the hearts and aortas of OVX rats. Melatonin should be considered in alleviating cardiovascular disease risk in postmenopausal women.

Molecular mechanism of inhibitory effects of melatonin on prostate cancer cell proliferation, migration and invasion

The increasing incidence of prostate cancer (PCa) indicates an urgent need for the development of new effective drug therapy. There are limited options to treat the PCa, this study tried to determine a new therapy option for this acute cancer. Androgen-independent PCa cell lines PC3 and DU145 were treated with different melatonin concentrations (0.1~3.5 mM) for 1~3 days and assessed cell migration, cell invasion, cycle arrest in G0/G1 phase as well as apoptosis. We utilized RNA-seq technology to analyze the transcriptional misregulation pathways in DU145 prostate cancer cell line with melatonin (0.5 mM) treatment. Data revealed 20031 genes were up and down-regulated, there were 271 genes that differentially expressed: 97 up-regulated (P<0.05) and 174 down-regulated (P<0.05) genes. Furthermore, RNA-seq results manifested that the melatonin treatment led to a significant increase in the expression levels of HPGD, IL2Rβ, NGFR, however, IGFBP3 and IL6 (P <0.05) had decreased expression levels. The immunoblot assay revealed the expression of IL2Rβ and NGFR genes was up-regulated, qPCR confirmed the gene expression of HPGD and IL2RB were also up-regulated in Du145 cells. Consequently, we probed mechanisms that generate kinetic patterns of NF-κB-dependent gene expression in PCa cells responding to a NF-κB-activation, the significant results were indicated by the inhibition of the NF-kB pathway via IL2Rβ actions. Based on our investigation, it could be concluded that melatonin is a chemotherapeutic molecule against PCa and provides a new idea for clinical therapy of PCa.

Melatonin and its mechanism of action in the female reproductive system and related malignancies

Melatonin (N-acetyl-5-methoxytryptamine), the main product of pineal gland in vertebrates, is well known for its multifunctional role which has great influences on the reproductive system. Recent studies documented that melatonin is a powerful free radical scavenger that affects the reproductive system function and female infertility by MT1 and MT2 receptors. Furthermore, cancer researches indicate the influence of melatonin on the modulation of tumor cell signaling pathways resulting in growth inhibitor of the both in vivo/in vitro models. Cancer adjuvant therapy can also benefit from melatonin through therapeutic impact and decreasing the side effects of radiation and chemotherapy. This article reviews the scientific evidence about the influence of melatonin and its mechanism of action on the fertility potential, physiological alteration, and anticancer efficacy, during experimental and clinical studies.

The Effect of Zinc and Melatonin Administration on Lipid Peroxidation, IL-6 Levels, and Element Metabolism in DMBA-Induced Breast Cancer in Rats

The purpose of this study was to investigate the effects of zinc and melatonin administration on interleukin-6, lipid peroxidation parameters, and element metabolism in DMBA-induced breast cancer in female rats. A total of 42 recently weaned Wistar rats were divided into 5 groups as follows: control (group 1), DMBA control (group 2), DMBA + zinc (group 3), DMBA + melatonin (group 4), and DMBA + melatonin and zinc (group 5). Malondialdehyde (MDA) and glutathione (GSH) levels in breast tissue and blood samples were determined via spectrophotometric methods. In addition, iron, magnesium, zinc, and copper levels in serum samples were determined by atomic emission, and plasma interleukin-6 levels were determined by ELISA method. The highest tissue and plasma MDA and the lowest tissue and erythrocyte GSH levels found in the study were in group 2; the highest tissue and erythrocyte GSH levels and the lowest tissue and plasma MDA levels are in group 5 (P < 0.05). Iron, magnesium, and zinc levels of groups 3, 4, and 5 were higher than the DMBA group without administration (group 2), but the copper values were significantly lower (P < 0.05). The highest IL-6 levels were determined in group 2 while IL-6 levels in the DMBA group (G5) treated with combined melatonin and zinc were lower than all other breast cancer groups (P < 0.05). According to the findings obtained in this presented study, combined zinc and melatonin therapy can contribute to the prevention of tumor growth by improving the disruption in element metabolism and suppressing IL-6 levels and reducing tissue damage that causes the cancer.

Melatonin potentiates the cytotoxic effect of Neratinib in HER2+ breast cancer through promoting endocytosis and lysosomal degradation of HER2

Complete blockade of the HER2 protein itself and HER signaling network is critical to achieving effective HER2-targeted therapies. Despite the success of HER2-targeted therapies, the diseases will relapse in a significant fraction of patients with HER2⁺ breast cancers. How to improve the therapeutic efficacy of existing HER2-targeted agents remains an unmet clinical need. Here, we uncover a role of Melatonin in diminishing HER2-mediated signaling by destruction of HER2 protein. Mechanistically, Melatonin treatment attenuated the protective effect of the HSP90 chaperone complex on its client protein HER2, triggering ubiquitylation and subsequent endocytic lysosomal degradation of HER2. The inhibitory effect of Melatonin on HER2 signaling substantially enhanced the cytotoxic effects of the pan-HER inhibitor Neratinib in HER2⁺ breast cancer cells. Lastly, we demonstrate that dual inhibition of HER2 by combined use of Melatonin and Neratinib effectively blocked the growth of HER2⁺ breast tumor xenografts in vivo. Our findings shed light on the potential use of Melatonin in a novel dual HER2 blockade strategy for HER2⁺ breast cancer treatment.

Melatonin and gastrointestinal cancers: Current evidence based on underlying signaling pathways

Gastrointestinal (GI) cancers, leading causes of cancer-related deaths, have been serious challenging human diseases up to now. Because of high rates of mortality, late-stage diagnosis, metastasis to distant locations, and low effectiveness and adverse events of routine standard therapies, the quality of life and survival time are low in patients with GI cancers. Hence, many efforts need to be done to explore and find novel efficient treatments. Beneficial effects of melatonin have been reported in a wide variety of human diseases. Melatonin has antioxidant, anti-inflammatory, antimicrobial, and anticancer effects. Various studies have showed the regulatory effects of melatonin on apoptotsis, autophagy and angiogenesis; these properties result in the inhibition of invasion, migration, and proliferation of GI cancer cells in vivo and in vitro. Together, this review suggests that melatonin in combination with anticancer agents may improve the efficacy of routine medicine and survival rate of patients with cancer.

A Potent Antioxidant Endogenous Neurohormone Melatonin, Rescued MCAO by Attenuating Oxidative Stress-Associated Neuroinflammation

Ischemic stroke is an acute neurological syndrome either due to permanent or temporary obstruction of blood. Such obstruction immediately triggers abrupt pathological cascading processes, which collectively lead to neuronal cell death. Oxidative stress and neuroinflammation in ischemic stroke are critical regulating events that ultimately lead to neuronal death. Complicated interplay exists between the two processes which occur through several stages. Most often, oxidative stress precedes the inflammatory mechanisms and includes several interconnected cascades that underlie the ischemic stroke pathology. In continuation of the previously published data, here, we further ruled out the protective role of melatonin in focal cerebral ischemic injury model. Administration of 5 mg/kg dose of melatonin 30 min prior to ischemia reduced brain infarction associated with sequentially rescued neuronal apoptosis. Furthermore, melatonin attenuated neuroinflammatory markers and reactive oxygen species (ROS), induced by ischemic stroke, via halting the key players of mitogen stress family (p38/JNK). Besides, melatonin modulated the endogenously produced antioxidant enzyme, thioredoxin (Trx) pathway. These broader therapeutic efficacies of melatonin suggest that melatonin could be further investigated for its diverse therapeutic actions with multiple targets in recovering, preventing and halting the detrimental outcomes of MCAO, such as elevated oxidative stress, neuroinflammation, and neurodegeneration.

Novel Melatonin, Estrogen, and Progesterone Hormone Therapy Demonstrates Anti-Cancer Actions in MCF-7 and MDA-MB-231 Breast Cancer Cells

A novel melatonin, estrogen, and progesterone hormone therapy was developed as a safe bio-identical alternative hormone therapy for menopausal women based on the Women’s Health Initiative findings that PremPro™ increased breast cancer risk and mortality of all types of breast cancer in postmenopausal women. For HER2 breast cancer, melatonin, estrogen, and progesterone delayed tumor onset and reduced tumor incidence in neu female mice. For other breast cancers, its actions are unknown. In this study, melatonin, estrogen, and progesterone hormone therapy were assessed in human ER+ (MCF-7) and triple negative breast cancer (MDA-MB-231) cells, and found to decrease proliferation and migration of both breast cancer lines. Inhibition of MEK1/2 and 5 using PD98059 and BIX02189, respectively, inhibited proliferation and migration in MDA-MB-231 cells and proliferation in MCF-7 cells; however, when combined with melatonin, estrogen, and progesterone, BIX02189 blocked melatonin, estrogen, and progesterone–mediated inhibition of migration in MCF-7 cells and induced Elf-5. For MDA-MB-231 cells, BIX02189 combined with melatonin, estrogen, and progesterone inhibited proliferation and increased pERK1/2 and β1-INTEGRIN; levels of pERK5 remained low/nearly absent in both breast cancer lines. These findings demonstrate novel anti-cancer actions of melatonin, estrogen, and progesterone in ER+ and triple negative breast cancer cells through intricate MEK1/2- and MEK5-associated signaling cascades that favor anti-proliferation and anti-migration.