Migraine
Charles Theisler in Adjuvant Medical Care, 2023
L-Tryptophan: Research has found that low dietary L-tryptophan and low plasma levels of serotonin are implicated in migraine pathogenesis.33 Some studies show that tryptophan supplementation might be as beneficial as prescription drugs for adults.34 In one study, tryptophan (9 gm/day) completely prevented migraine in three of five patients and reduced the frequency of migraine in a fourth.35 In a second study, tryptophan 500 mg every six hours for three months helped four of eight migraine patients.36 L-tryptophan or 5-HTP (e.g., 8–12 gm/day) as an adjuvant therapy has been recommended for refractory migraine patients37 and may lessen the susceptibility to more severe headaches, nausea, and sensitivity to light.38
Depression, Anxiety, Stress, and Spirituality in Cardiovascular Disease
Stephen T. Sinatra, Mark C. Houston in Nutritional and Integrative Strategies in Cardiovascular Medicine, 2022
L-Tryptophan and 5-hydroxytryptamine (5-HTP) have been used to increase levels of serotonin, in lieu of SSRI medication for depression and anxiety. L-Tryptophan intake at a dose of 2 g three times per day was studied in the 1970s and found to have equivalent outcomes with TCAs.129 Since this time, it has become more controversial due to its potential interaction with SSRIs and development of serotonin syndrome. In addition, eosinophilic myalgia syndrome was linked to a contaminant in tryptophan supplements. However, if no serotonin-producing drugs are being utilized, tryptophan and 5-HTP can serve to potentiate serotonin and decrease depressive or anxious symptoms, provided that a source made to pharmaceutical grade is utilized. A study performed by Lu and colleagues found that in an animal model, a post-MI population had lower 5-HTP levels in the hippocampus, suggesting this as a potential mechanism of post-cardiac event depression.130 A proposed mechanism of low tryptophan in depression is based upon HPA axis regulation of tryptophan.131 Since HPA axis dysregulation in itself is a mechanism of correlation between depression and CVD, targeting HPA axis regulation is also an area of treatment.
The Chemistry of the Brain
Gail S. Anderson in Biological Influences on Criminal Behavior, 2019
Many serotonin studies have either experimentally depleted or supplemented tryptophan to reduce or elevate available serotonin. Medically, it is simple to acutely deplete tryptophan in individuals for a short period. A review of such studies has shown that although the results vary, general healthy individuals do not show any change in mood, but healthy individuals who have a familial history of depression do show mood depression, although still within the normal range.32 In depressed patients who are recovered and are on antidepressant treatment that modulates the serotonergic system, at least half experience a regression to full depression, but in those no longer on medications, the response is much smaller.32 It appears clear that blocking serotonin production can depress mood in some people and seems to have a greater effect on people vulnerable to depression. Many studies have also used acute tryptophan depletion to study aggression, and most found increased irritability or aggression with depleted tryptophan, but unlike mood, it did not relate to whether the individual was normally aggressive.32 In other studies, tryptophan was supplemented to increase serotonin synthesis. Many human and animal studies have shown the prosocial benefits of increased serotonin levels, with supplementation reducing irritability and increasing friendly behavior.32
Pharmacotherapeutic management of sleep disorders in children with neurodevelopmental disorders
Published in Expert Opinion on Pharmacotherapy, 2019
Oliviero Bruni, Marco Angriman, Maria Grazia Melegari, Raffaele Ferri
Tryptophan is an essential plant-derived amino acid that is needed for the in vivo biosynthesis of proteins. After consumption, it is metabolically transformed to bioactive metabolites, including serotonin, melatonin, kynurenine, and the vitamin niacin (nicotinamide). As early as 1974, the use of L-tryptophan (LT) was suggested as a natural hypnotic and was widely used in the 80s for the treatment of sleep disorders and headache prophylaxis. LT produces a negligible decrease in REM sleep and increase in NREM sleep [129], does not have opioid-like effects, and does not limit cognitive performance or inhibit arousal from sleep [130]. Several positive effects on sleep have been reported in the literature: improvement of SL and decrease in arousal [131,132]. One study with LT at different doses (250 mg, 1 g, and 3 g) in adults showed improvement in SL and a reduction in WASO, with a moderate effect on sleep quality. None of the papers reported systematic information regarding adverse effects associated with tryptophan [133–135].
Inhibition of hormonal and behavioral effects of stress by tryptophan in rats
Published in Nutritional Neuroscience, 2019
Sumera Gul, Darakhshan Saleem, Muhammad A. Haleem, Darakhshan Jabeen Haleem
Tryptophan is an essential amino acid; its source is therefore dietary.14 It is reported in a clinical investigation that fasting as well as postprandial plasma levels of leptin are increased and those of ghrelin decreased in normal healthy controls given an oral dose of 500 mg/kg tryptophan.15 Because exposure to stress increases circulating leptin and injected leptin can reduce stress effects on behavior,5,6 we hypothesize that exogenous tryptophan will produce a greater increase in circulating leptin in stressed animals to reduce stress effects on behavior. The present study was therefore designed to monitor effects of orally administered tryptophan on serum levels of leptin, ghrelin, food intake, and behavior in an elevated plus maze in unstressed and stressed animals. In view of tryptophan-induced increases of serum serotonin16 playing a role in leptin release from the adipocytes,17 circulating levels of tryptophan and serotonin are also determined. In the first part of the study, effects of tryptophan at doses of 100, 200, and 300 mg/kg were determined on circulating levels of leptin and ghrelin. A dose of tryptophan (300 mg/kg) selected from the dose response study was used to investigate effects of tryptophan on serum serotonin, leptin, ghrelin, food intake, and behavior in the elevated plus maze in rats exposed to immobilization and in unstressed controls.
Pharmacotherapeutic options for co-morbid depression and alcohol dependence
Published in Expert Opinion on Pharmacotherapy, 2019
Thomas Hillemacher, Helge Frieling
Tryptophan is an amino acid and precursor for serotonin synthesis. It is used as a dietary supplement for reducing depressive symptoms. In a randomized, double-blind, placebo-controlled study of 76 alcoholic male inpatients with serious depression, L-tryptophan (3 g over 4 days) led to a significant improvement of depression and sleep [83]. Patients were randomized on L-tryptophan or placebo for four days. After a four-day washout period, the treatments were reversed in both groups. There was a third group that received placebo on all occasions and two other groups that received no treatment. Although these findings were intriguing, the design of the study prevents clear data interpretation. All subjects reported decreased levels of depression perhaps due to nonspecific treatment. More research is required to corroborate these findings. No other study with tryptophan fulfilled our criteria.
Related Knowledge Centers
- Aromatic Compound
- Biosynthesis
- Carboxylic Acid
- Indole
- Protein
- Amino Acid
- Neurotransmitter
- Serotonin
- Locant
- Hormone