Possible Interaction: Melatonin and Tryptophan

“Plasma level of melatonin was significantly elevated in groups treated with tryptophan (group I) and melatonin (group II), but remained unchanged in placebo-treated group (group III).”

“Acute TRP depletion has recently been shown to decrease nocturnal plasma levels of melatonin in humans.”

“Evidence is presented that some effects of L-Trp on sleep may be mediated by melatonin , a Trp-metabolite with sedative properties.”

“The infusions of L-Trp caused a massive elevation of plasma melatonin levels.”

“ Melatonin premedication significantly reduced the GH response to peroral L-tryptophan loading, suggesting that melatonin affects GH secretion in man by interfering with serotonergic transmission.”

“Melatonin is synthesized from tryptophan within the pineal gland, which is located outside the blood-brain barrier, and overproduction of melatonin may lead to augmented consumption of tryptophan , from which serotonin is synthesized.”

“According to our experience, after oral application of Trp , the plasma MT increases in dose-dependent manner both in intact and pinealectomized animals and humans, indicating that GIT but not the pineal gland is a source of this indole.”

“The ingestion of L-tryptophan during the day is hypothesized to increase the levels of melatonin , released from the gastrointestinal tract, in patients with winter seasonal affective disorder (SAD).”

“In vitiligo, the metabolically blunted L-tryptophan levels in the epidermis affect melatonin levels and the T cell-mediated melanocyte destruction leads to melanin depletion [10].”

“OBJECTIVES Previous studies have shown that tryptophan and vitamin B6 used in conjunction with melatonin induce sleep more effectively than melatonin alone.”

“BackgroundTryptophan (TRP) is an essential amino acid, and it has been suggested that TRP intake at breakfast combined with daytime bright light exposure can increase nocturnal melatonin secretion.”