Melatonin madness is everywhere! The media attention that melatonin has received recently is truly remarkable and has elevated the hormone to cult status. Is all this excitement really justified, or is it just hype? What does melatonin actually do? Does it signal through specific receptors like other hormones? What is its true therapeutic potential? This minireview addresses these questions and...

Since mammalian skin expresses the enzymatic apparatus for melatonin synthesis, it may be an extrapineal site of melatonin synthesis. However, evidence is still lacking that this is really the case in situ. Here, we demonstrate melatonin-like immunoreactivity (IR) in the outer root sheath (ORS) of mouse and human hair follicles (HFs), which corresponds to melatonin, as shown by radioimmunoassay...

Background: The relationship between the high activity of aldose reductase (AR) and diabetic cataract formation has been previously investigated. The purpose of the present study was to determine the preventing effect of melatonin on streptozotocin (STZ)-induced diabetic cataract in rats.Methods: 34 adult healthy male Sprague-Dawely rats were divided into four groups. Diabetic control and diabe...

Melatonin is a new plant hormone that plays an important role in stress tolerance. For investigation the effect of exogenous application of melatonin on salt tolerance in rosemary (Rosmarinus officinalis L.), a factorial experiment was conducted in a completely randomized design with three replications. The first factor was melatonin (50, 100 µM) and the second factor was salinity stress (6, 9,...

BACKGROUND Melatonin possesses antioxidant, free-radical scavenging, and immunoenhancing properties that promote fibroblast activity and bone regeneration. The aim of this study was to examine the possible links between salivary melatonin levels and the severity of periodontal disease using the community periodontal index (CPI). METHODS Thirty-seven patients with different degrees of periodon...

2-DG triggers glucose deprivation without altering other nutrients or metabolic pathways and then activates autophagy via activation of AMPK and endoplasmic reticulum (ER) stress. We investigated whether 2-DG reduced intracellular insulin increased by melatonin via autophagy/EDC3 in insulinoma INS-1E cells. p-AMPK and GRP78/BiP level were significantly increased by 2-DG in the presence/absence ...

Small laboratory animals have provided significant information about melatonin regulation, yet most of these organisms are nocturnal and regulate melatonin synthesis by mechanisms that diverge from those of humans. For example, in all rodents examined, melatonin secretion occurs with a time lag of several hours after the onset of darkness; in addition, arylalkylamine N-acetyltransferase (AANAT)...

CONTEXT Millions of individuals habitually expose themselves to room light in the hours before bedtime, yet the effects of this behavior on melatonin signaling are not well recognized. OBJECTIVE We tested the hypothesis that exposure to room light in the late evening suppresses the onset of melatonin synthesis and shortens the duration of melatonin production. DESIGN In a retrospective anal...

As a typical warm-season grass, Bermudagrass [Cynodon dactylon (L).Pers.] is widely applied in turf systems and animal husbandry. However, cold temperature is a key factor limiting resource utilization for Bermudagrass. Therefore, it is relevant to study the mechanisms by which Burmudagrass responds to cold. Melatonin is a crucial animal and plant hormone that is responsible for plant abiotic s...

Melatonin is a neuroendocrine hormone secreted by the pineal gland to transduce the body’s circadian rhythms. An internal 24 hour time keeping system (biological clock) regulated by melatonin, controls the sleep-wake cycle. Melatonin production is a highly conserved evolutionary phenomenon. The indole hormone is synthesized in the pinealocytes derived from photoreceptors. Altered patterns and/o...