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Ayahuasca
Published in Mahendra Rai, Shandesh Bhattarai, Chistiane M. Feitosa, Wild Plants, 2020
Raquel Consul, Flávia Lucas, Maria Graça Campos
DMT is a classic hallucinogenic compound considered illicit by the 1971 United Nations Convention on Psychotropic Substances (UN 1971). It belongs to the class of indolamines due to its bicyclic structure, through the combining of a benzene group with a pyrrole group, which forms the indole nucleus, common to serotonin and melatonin (Araújo et al. 2015, Cameron and Olson 2018).
Endocrine Functions of Brain Dopamine
Published in Nira Ben-Jonathan, Dopamine, 2020
The pineal gland is a small structure located on the epithalamus. Its main secretory product is melatonin, which is synthesized from tryptophan by four enzymatic steps in the indoleamine biosynthetic pathway (Figure 4.2). Dietary tryptophan is absorbed into the bloodstream from the gut and is circulated through the body. In cells that express tryptophan hydroxylase (TPOH), tryptophan is hydroxylated to 5-hydroxy-tryptophan in the mitochondria, followed by decarboxylation by aromatic amino acid decarboxylase (AADC; the same enzyme that converts L-Dopa to DA) to serotonin (5-hydroxy-tryptamine or 5-HT). Serotonin is the final product of the indoleamine pathway in many brain and peripheral locations, where it functions as a neurotransmitter and/or a hormone. In the pineal gland, however, serotonin is further acetylated on its free amine by serotonin N-acetyl transferase (AANAT), followed by O-methylation on the hydroxyl group by acetyl-serotonin-O-methyl transferase (ASMT), generating melatonin. Among the four biosynthetic enzymes in the pineal, the activities of TPOH and AANAT increase at night, while those of AADC and HIOMT run continuously.
Neuroendocrine Regulation of Hematopoiesis
Published in Herman Friedman, Thomas W. Klein, Andrea L. Friedman, Psychoneuroimmunology, Stress, and Infection, 2020
Melatonin is an indoleamine synthesized from serotonin. Its synthesis and release which occur primarily in the pineal gland follows a circadian rhythm with the highest blood concentration occurring at night in all species.19 In previous work we have shown that melatonin can correct immunodeficiency states which may follow acute stress, viral diseases, aging or drug treatment9 We also observed that melatonin was able to antagonize the effect of high dose cyclophosphamide on antibody production.20 This finding has been then confirmed and extended by other authors.21,22 Such interesting effects of melatonin seem to depend on activated CD4+, T-cells which upon melatonin stimulation show an enhanced synthesis and/or release of opioid peptides, IL-2 and γ-interferon.9,22–24 On the basis of our animal studies,9 we have investigated the clinical effect of melatonin in association with low-dose interleukin-2 in cancer patients and found that this association represents a well tolerated strategy capable of determining an apparent control of tumor growth in patients with advanced solid neoplasms.25–28
Prevalence of eating disorders and disordered eating in Western Asia: a systematic review and meta-Analysis
Published in Eating Disorders, 2022
Maryam Alfalahi, Sangeetha Mahadevan, Rola al Balushi, Moon Fai Chan, Muna Al Saadon, Samir Al-Adawi, M. Walid Qoronfleh
Body image dissatisfaction is increasingly becoming a global phenomenon and is concurrently associated with eating disorders (Garrusi et al., 2016; Nobakht & Dezhkam, 2000; Tahmouresi & Pashang, 2018). In addition to the socio-cultural factors that contribute to eating disorders, there are also certain biological factors that render some individuals vulnerable to developing eating disorders. Gray (1987) has suggested that human temperaments can be shaped by two biological systems. The first one known as the BIS (behavioral inhibition system) is characterized by inhibition or avoidance. The complementary system is known as BAS (behavioral activation system) which is characterized by a tendency for impulsiveness and sensation-seeking behavior. There is evidence to suggest that characteristics of BIS/BAS, sensitivity to reward and punishment or approach and avoidance motivation (e.g., high constraint, constriction of affect, emotional expressiveness, anhedonia, sensation-seeking or lack of it, perfectionism, obsessiveness) are common among individuals with eating disorders (Claes et al., 2006). There is also evidence to suggest that eating disorders are critically influenced by variations in catecholamine and indoleamine neurotransmission (Kaye, 1997).
Agomelatine potentiates anti-nociceptive effects of morphine in a mice model for diabetic neuropathy: involvement of NMDA receptor subtype NR1 within the raphe nucleus and periaqueductal grey
Published in Neurological Research, 2020
Sibel Ozcan, Ozgur Bulmus, Nazife Ulker, Sinan Canpolat, Ebru Onalan Etem, Sinem Oruc, Ahmet Yardimci, Funda Gülcü Bulmus, Ahmet Ayar, Haluk Kelestimur, Mete Ozcan
Agomelatine, which is an atypical antidepressant with a novel mechanism of action being a potent agonist at melatonin receptors (MT1 and MT2) and an antagonist at serotonin (5-hydroxytryptamine (5-HT2C)) receptor [4], seems to have a potential of new indication for pain management. Both melatonin and serotonin are indolamines which are known to be involved in the pain modulation [5,6]. There are studies showing that melatonin shows analgesic effects in a dose-dependent manner [6] and prevents morphine hyperalgesia [7]. However, possible interaction of agomelatine and morphine on pain management remains unknown. Agomelatine has been shown to have an antinociceptive effect in animal models [8], and it has modulatory actions on cellular model of nociceptive signalling [9]. Recent studies have suggested that agomelatine may also be effective on neuropathic pain [10,11].
Melatonin ingestion after exhaustive late-evening exercise attenuate muscle damage, oxidative stress, and inflammation during intense short term effort in the following day in teenage athletes
Published in Chronobiology International, 2020
Mohamed Cheikh, Khouloud Makhlouf, Kais Ghattassi, Ahmed Graja, Salyma Ferchichi, Choumous Kallel, Mallek Houda, Nizar Souissi, Omar Hammouda
Among variables related to performance sport protocols, the influence of endogenous and exogenous MEL has been a common topic (López-Flores et al. 2018). MEL might have positive effects on the recovery following the exercise session (Diaz-Castro et al. 2017). In fact, several studies have shown that oral supplementation of MEL during high-intensity exercise is efficient in reducing the degree of oxidative stress (decreasing lipid peroxidation, with significant increase of antioxidant enzymes activity), which lead to the maintenance of the cell integrity and the reduction of secondary tissue damage. Data indicate that MEL has potent protective effects, preventing overexpression of pro-inflammatory mediators and inhibiting the effects of several pro-inflammatory cytokines (Diaz-Castro et al. 2017). Despite meaningful information regarding MEL effects on circadian rhythm modulation, sleep disorder, jet lag treatment, and health application, the effects of this indoleamine on exercise performances remain uncertain (Beck et al. 2018), and only few studies have tried to demonstrate a connection between the two (López-Flores et al. 2018). Interestingly, in human studies regarding MEL, we could find interventions on sleep time to improve resting state (and then expect better performances) (Halson 2014; Zhao et al. 2012). In this sense, Ghattassi et al. (2014) showed that MEL ingestion before nocturnal exercise does not affect short-term performances before nocturnal sleep. These findings could confirm the sleep effects due to MEL on performances.