Melatonin, immune function and aging

Abstract

Aging is associated with a decline in immune function (immunosenescence), a situation known to correlate with increased incidence of cancer, infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration with age. A decrease in functional competence of individual natural killer (NK) cells is found with advancing age. Macrophages and granulocytes show functional decline in aging as evidenced by their diminished phagocytic activity and impairment of superoxide generation. There is also marked shift in cytokine profile as age advances, e.g., CD3+ and CD4+ cells decline in number whereas CD8+ cells increase in elderly individuals. A decline in organ specific antibodies occurs causing reduced humoral responsiveness. Circulating melatonin decreases with age and in recent years much interest has been focused on its immunomodulatory effect. Melatonin stimulates the production of progenitor cells for granulocytes-macrophages. It also stimulates the production of NK cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from NK cells and T-helper lymphocytes also are enhanced by melatonin. Melatonin presumably regulates immune function by acting on the immune-opioid network, by affecting G protein-cAMP signal pathway and by regulating intracellular glutathione levels. Melatonin has the potential therapeutic value to enhance immune function in aged individuals and in patients in an immunocompromised state.

Nanopalladium grained polymer nanocomposite based sensor for the sensitive determination of Melatonin

“…The pineal hormone, MEL, is associated with mood regulation, sleep efficiency, dreaming, immunologic functions, retinal physiology, seasonal affective disorder, sexual maturation, reproduction [21,22,23] and is an effective antioxidant, antiinflammatory agent. MEL is known to be a very effective free radical scavenger, which has the ability to protect tissues from the reactive oxygen and nitrogen species [24,25].…”

Subthreshold Concentrations of Melatonin and Galantamine Improves Pathological AD-Hallmarks in Hippocampal Organotypic Cultures

“…Besides the pineal gland, melatonin is also produced in gastrointestinal tract, thymus, adrenal glands, thyroid gland, and other organs [41]. It must be noted that melatonin production declines with aging [13,42,43] due to dysfunction of the sympathetic regulation of pineal melatonin by the suprachiasmatic nucleus. The loss of melatonin during aging contributes to oxidative stress accumulation because its antioxidant effect is lost, and thereby it contributes to the progression of diseases with a free radical component like neurodegenerative diseases [13] or cardiovascular disease [44].…”

Effect constant and natural illumination on physiological state in rats

“…В последние годы значительное внимание уделяется взаимодействию между пинеальной железой и иммунной системой (Guerrero, Reiter, 2002;Maestroni, 2001;Srinivasan et al, 2005;Moore et al, 2002). Особенно существенна роль мелатонина как иммуномодулятора при нарушениях иммунологического статуса, вызванных снижением эндогенного уровня гормона при функциональных и фармакологических воздействиях (Srinivasan et al, 2005;Moore et al, 2002). Уровень мелатонина положительно коррелирует как с гуморальным (Akbulut et al, 2001), так и с клеточным иммунитетом (Brennan et al, 2002;Champney et al, 1997).…”