Beneficial Effects of Melatonin and Atorvastatin on Retinopathy in Streptozocin-induced Diabetic Rats

Practical application of melatonin for pancreas disorders: protective roles against inflammation, malignancy, and dysfunctions

Melatonin, a hormone primarily produced by the pineal gland, exhibits a range of physiological functions that extend beyond its well-known role in regulating circadian rhythms. This hormone influences energy metabolism, modulates insulin sensitivity, and plays a significant role in controlling sleep patterns and food intake. Notably, melatonin is also synthesized in various peripheral organs, including the gastrointestinal system and pancreas, suggesting its function as a local hormone. The presence of melatonin receptors in the pancreas underscores its relevance in pancreatic physiology. Pancreatic disorders, such as diabetes mellitus (DM), pancreatitis, and pancreatic cancer, often stem from inflammatory processes. The majority of these conditions are characterized by dysregulated immune responses and oxidative stress. Melatonin's anti-inflammatory properties are mediated through the inhibition of pro-inflammatory cytokines and the activation of antioxidant enzymes, which help to mitigate cellular damage. Furthermore, melatonin has demonstrated pro-apoptotic effects on cancer cells, promoting cell death in malignant tissues while preserving healthy cells. Thus, melatonin emerges as a multifaceted agent with significant therapeutic potential for pancreatic disorders. Its ability to reduce inflammation and oxidative stress positions it as a promising adjunct therapy for conditions such as diabetes mellitus, pancreatitis, and pancreatic cancer. By modulating immune responses and enhancing cellular resilience through antioxidant mechanisms, melatonin not only addresses the symptoms but also targets the underlying pathophysiological processes associated with these disorders. This review aims to categorize and summarize the impacts of melatonin on pancreatic functions and disorders, emphasizing its potential as a therapeutic agent for managing pancreatic dysfunctions. Future research should focus on elucidating the precise mechanisms by which melatonin exerts its protective effects on pancreatic tissues and exploring optimal dosing strategies for clinical applications. The integration of melatonin into treatment regimens may enhance existing therapies and offer new hope for individuals suffering from pancreatic dysfunctions.

Melatonin: Current evidence on protective and therapeutic roles in gynecological diseases

Melatonin, a potent antioxidant and free radical scavenger, has been demonstrated to be effective in gynecological conditions and female reproductive cancers. This review consolidates the accumulating evidence on melatonin's multifaceted protective effects in different pathological contexts. In gynecological conditions such as endometriosis, polycystic ovary syndrome (PCOS), and uterine leiomyoma, melatonin has shown promising effects in reducing oxidative stress, inflammation, and hormonal imbalances. It inhibits adhesion molecules' production, and potentially mitigates leukocyte adherence and inflammatory responses. Melatonin's regulatory effects on hormone production and insulin sensitivity in PCOS individuals make it a promising candidate for improving oocyte quality and menstrual irregularities. Moreover, melatonin exhibits significant antitumor effects by modulating various signaling pathways, promoting apoptosis, and suppressing metastasis in breast cancers and gynecological cancers, including ovarian, endometrial, and cervical cancers. Furthermore, melatonin's protective effects are suggested to be mediated by interactions with its receptors, estrogen receptors and other nuclear receptors. The regulation of clock-related genes and circadian clock systems may also contribute to its inhibitory effects on cancer cell growth. However, more comprehensive research is warranted to fully elucidate the underlying molecular mechanisms and establish melatonin as a potential therapeutic agent for these conditions.

The effects of vitamin D3 and melatonin combination on pentylenetetrazole-induced seizures in mice

BACKGROUND

Epileptic seizures are associated with the overproduction of free radicals in the brain leading to neuronal cell death. Therefore, reduction of oxidative stress may inhibit seizure-induced neuronal cell damage. Current study evaluated the effects of Vit D3 and melatonin and their combination on pentylenetetrazol (PTZ)-induced tonic clonic seizures in mice.

METHODS

Animals were divided into six groups. Group I was administrated with normal saline (0.5 ml, intraperitoneally (i.p.)) on the 15th day of experiment. Group II was injected with PTZ (60 mg/kg dissolved in 0.5 ml normal saline, i.p) on the 15th day. Groups III-IV were treated with diazepam (4 mg/kg/day), Vit D3 (6000 IU/kg/day), melatonin (20 mg/kg/day) and Vit D3 (6000 IU/kg/day)/melatonin (20 mg/kg/day), respectively, and were then injected with PTZ (60 mg/kg) on the 15th day of experiment. Immediately after the injection of PTZ on the 15th day, mice were observed for a 30-min period for the measurement of seizure latency and duration. For determination of oxidative stress markers, malondialdehyde (MDA) level and superoxide dismutase (SOD) activity were measured in mouse brains.

RESULTS

Treatment with Vit D3, melatonin, and Vit D3/melatonin significantly increased seizure latency and decreased seizure duration. The brain level of MDA was lower and SOD activity was greater than the PTZ group. Mice treated with Vit D3/melatonin had lower seizure duration compared to other treated groups.

CONCLUSIONS

Combination of Vit D3 and melatonin may reduce seizure frequency in epileptic patients; this effect may result from various mechanisms including inhibition of oxidative stress.

SARS-CoV-2 and other coronaviruses negatively influence mitochondrial quality control: beneficial effects of melatonin

Coronaviruses (CoVs) are a group of single stranded RNA viruses, of which some of them such as SARS-CoV, MERS-CoV, and SARS-CoV-2 are associated with deadly worldwide human diseases. Coronavirus disease-2019 (COVID-19), a condition caused by SARS-CoV-2, results in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) associated with high mortality in the elderly and in people with underlying comorbidities. Results from several studies suggest that CoVs localize in mitochondria and interact with mitochondrial protein translocation machinery to target their encoded products to mitochondria. Coronaviruses encode a number of proteins; this process is essential for viral replication through inhibiting degradation of viral proteins and host misfolded proteins including those in mitochondria. These viruses seem to maintain their replication by altering mitochondrial dynamics and targeting mitochondrial-associated antiviral signaling (MAVS), allowing them to evade host innate immunity. Coronaviruses infections such as COVID-19 are more severe in aging patients. Since endogenous melatonin levels are often dramatically reduced in the aged and because it is a potent anti-inflammatory agent, melatonin has been proposed to be useful in CoVs infections by altering proteasomal and mitochondrial activities. Melatonin inhibits mitochondrial fission due to its antioxidant and inhibitory effects on cytosolic calcium overload. The collective data suggests that melatonin may mediate mitochondrial adaptations through regulating both mitochondrial dynamics and biogenesis. We propose that melatonin may inhibit SARS-CoV-2-induced cell damage by regulating mitochondrial physiology.