[Peptide correction of age-related pineal disturbances in monkeys].
Level 5 - mechanism / opinion, no new human data
Animal study in nonhuman primates without human clinical data
What was done
Researchers evaluated pineal gland function and the effects of pineal peptide preparations in 38 female rhesus macaques (*Macaca mulatta*) across two age groups: young (6–8 years old, n = 18) and old (20–26 years old, n = 20). Plasma melatonin concentrations were assessed across diurnal rhythms under basal conditions and following intramuscular administration of epithalamin (5 mg/animal/day for 10 consecutive days) or epitalon (10 mcg/animal/day for 7–10 consecutive days).
What was found
Plasma melatonin exhibited a diurnal rhythm peaking between 10:00 p.m. and 3:00 a.m. and reaching a minimum at 4:00 p.m. In aged monkeys, mean diurnal melatonin concentrations were decreased 1.5- to 2-fold compared with young monkeys, with lower levels noted at 9:00 p.m., 10:00 p.m., 3:00 a.m., and 4:00 a.m. Administration of epithalamin or epitalon induced a significant increase in nighttime plasma melatonin in old monkeys, while producing no change in young monkeys. Absolute numerical concentrations and measures of variance were not reported in the abstract.
Why it matters
This study indicates that age-related declines in nocturnal melatonin secretion in nonhuman primates can be stimulated by pineal peptide formulations.
Limits
The study was conducted in female rhesus monkeys only, limiting direct generalizability to humans and males. The abstract does not provide exact baseline or post-treatment numerical values, standard deviations, confidence intervals, p-values, or long-term safety and outcome data.
Cited by
- supports Epithalamin administration upregulates melatonin synthesis enzymes and restores melatonin production in aged monkeys and humans.