The roles of melatonin and resveratrol-enhanced activation of SIRT1 (silent information regulator 1), GLUT4 (glucose transporter type 4), and PGC-1α (peroxisome proliferator-activated receptor gamma coactivator 1-alpha) in mediating the protective effects on the heart in aged female rats with streptozotocin-induced diabetes were investigated. 16-month-old 48 Wistar female rats were separated into 8 groups with equal numbers. Group 1: Control, Group 2: Resveratrol Control, Group 3: Melatonin Control, Group 4: Resveratrol and Melatonin Control, Group 5: Diabetes, Group 6: Diabetes Resveratrol, Group 7: Diabetes Melatonin, Group 8: Diabetes Resveratrol and Melatonin. A single dose of 40 mg/kg intraperitoneal streptozotocin was injected into the rats of Groups 5, 6, 7, and 8 to induce experimental diabetes. Blood glucose levels were measured from the tail veins of the animals six days after the injections, using a diagnostic glucose kit. Rats with a blood glucose levels ≥300 mg/dl were considered diabetic. 5 mg/kg/day of resveratrol (intraperitoneal) and melatonin (subcutaneous) were administered for four weeks. At the end of the applications, SIRT1, GLUT4, PGC-1α gene expression as well as MDA and GSH levels in the heart tissues were determined by the PCR method from heart tissue samples taken under general anesthesia. The findings of our study show that suppressed antioxidant activity and decreased GLUT4, SIRT1, and PGC-1α gene expression in heart tissue can be reversed by the combination of resveratrol, melatonin, and resveratrol + melatonin in a diabetic aged female rat model. Resveratrol and melatonin supplementation may have a protective effect on cardiac functions in the diabetic aged female rat model.

Neurodegenerative conditions, including Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease, result in a substantial health problem for the elderly, marked by ongoing neuronal degeneration and a deterioration in mental faculties. These disorders are frequently linked to oxidative stress, problems with mitochondria, and persistent inflammation in the brain, which worsen neuronal damage. The neurohormone melatonin, primarily secreted by the pineal gland, has gained recognition as a promising therapeutic agent due to its antioxidant, anti-inflammatory, and neuroprotective effects. Melatonin’s functions extend beyond its regulation of circadian rhythms, as research has demonstrated its ability to remove free radicals, improve mitochondrial performance, and adjust immune system responses, ultimately reducing the progression of neurodegenerative disease. Research findings from preclinical and clinical trials imply that taking melatonin supplements could lead to improved cognitive abilities, slower disease progression, and an overall better quality of life for elderly individuals suffering from neurodegenerative conditions. The mechanisms through which melatonin acts, the best dosage, and its long-term effectiveness are still being researched. This review underscores the potential benefits of melatonin as a supplementary treatment for neurodegenerative disorders in older adults, stressing the necessity for additional studies to confirm its efficacy and standardize its use in treatment plans.

Objective: In this study, it was aimed to investigate the relationship between the pineal gland and ghrelin and nesfatin-1 hormones in rats. Methods: A total of 36 male rats were used in the study, and the animals were divided into 4 groups. Group 1, Control; Group 2, Pinealectomy (Px); Group 3, Px+Melatonin; Group 4 Melatonin. After the end of the experimental applications, melatonin, ghrelin and nesfatin-1 levels (ELISA) were determined in the blood samples taken from the animals. Results: While pinealectomy resulted in suppression of melatonin levels, melatonin supplementation led to a significant increase in blood melatonin levels (p<0.01). Melatonin supplementation suppressed ghrelin levels, while pinealectomy increased ghrelin levels (P<0.01). On the other hand, Nesfatin-1 levels, which increased with melatonin support, were significantly suppressed by pinealectomy (p<0.01). Conclusion: The results of the current study show that the pineal gland may have important effects on the hormones ghrelin and nesfatin-1, which play critical roles in nutrition. In conclusion melatonin supplementation inhibites ghrelin, and but increases nesfatin-1.