Effects of peptides on generation of reactive oxygen species in subcellular fractions of Drosophila melanogaster

Epitalon protects against post-ovulatory aging-related damage of mouse oocytes in vitro

The developmental potential of oocytes decreases with time after ovulation in vivo or in vitro. Epitalon is a synthetic short peptide made of four amino acids (alanine, glutamic acid, aspartic acid, and glycine), based on a natural peptide called epithalamion extracted from the pineal gland. It is a potent antioxidant, comparable to melatonin, that may confer longevity benefits. The current study aims to test the protective effects of Epitalon on the quality of post-ovulatory aging oocytes. Epitalon at 0.1mM was added to the culture medium, and the quality of oocytes was evaluated at 6h, 12h, and 24h of culture. We found that 0.1mM Epitalon reduced intracellular reactive oxygen species. Epitalon treatment significantly decreased frequency of spindle defects and abnormal distribution of cortical granules during aging for 12h and 24h, while increased mitochondrial membrane potential and DNA copy number of mitochondria, thus decreasing apoptosis of oocytes by 24h of in vitro aging. Our results suggest that Epitalon can delay the aging process of oocytes in vitro via modulating mitochondrial activity and ROS levels.

Empowering Melatonin Therapeutics with Drosophila Models

Melatonin functions as a central regulator of cell and organismal function as well as a neurohormone involved in several processes, e.g., the regulation of the circadian rhythm, sleep, aging, oxidative response, and more. As such, it holds immense pharmacological potential. Receptor-mediated melatonin function mainly occurs through MT1 and MT2, conserved amongst mammals. Other melatonin-binding proteins exist. Non-receptor-mediated activities involve regulating the mitochondrial function and antioxidant cascade, which are frequently affected by normal aging as well as disease. Several pathologies display diseased or dysfunctional mitochondria, suggesting melatonin may be used therapeutically. Drosophila models have extensively been employed to study disease pathogenesis and discover new drugs. Here, we review the multiple functions of melatonin through the lens of functional conservation and model organism research to empower potential melatonin therapeutics to treat neurodegenerative and renal diseases.

Drosophila as an emerging model organism for studies of food-derived antioxidants

Dietary supplementation with antioxidants provides health benefits by preventing diseases caused by oxidative stress and damage. Consequently, there has been growing interest in the study of antioxidative foods and their active ingredients. Oxidative stress and antioxidative responses are mechanistically conserved from Drosophila to mammals. Therefore, as a well-established model organism with a short life cycle and advantages of genetic manipulation, the fruit fly has been increasingly employed to assess functions of antioxidants in vivo. In this review, the antioxidative defense mechanisms, methods used and assays developed in Drosophila to evaluate antioxidant supplementation, are highlighted. The main manifestations of antioxidation include reduction of reactive species, up-regulation of endogenous antioxidants, inhibition on oxidative damage to biomacromolecules, enhanced resistance against oxidative stress and extension of lifespan, which are related to the activations of nuclear factor erythroid 2-related factor 2-antioxidant response element pathway and other adaptive responses. Moreover, the key considerations and future perspectives for the application of Drosophila models in the studies of food-derived antioxidants are discussed.

Peptide bioregulation of aging: results and prospects

The review comprises the results of author's long-term investigation in the mechanisms of aging and a role of peptide bioregulators in prevention of age-related pathology. A number of small peptides have been isolated from different organs and tissues and their analogues (di-, tri-, tetrapeptides) were synthesized from the amino acids. It was shown that long-term treatment with some peptide preparations increased mean life span by 20-40%, slow down the age-related changes in the biomarkers of aging and suppressed development of spontaneous and induced by chemical or radiation carcinogens tumorigenesis in rodents. Possible mechanisms of the biological effects of small peptides are discussed in the paper. The results of clinical applications of peptide preparation during the period of 6-12 years are presented as well.