Affron® supplementation reduces kynurenine levels and promotes melatonin synthesis. - GreenMedInfo Summary

Melatonin is a hormone that regulates sleep-wake cycles and is mainly synthesized in the pineal gland from tryptophan after its conversion into serotonin. Under normal conditions, less than 5% of tryptophan is reserved for the synthesis of serotonin and melatonin. The remaining 95% is metabolized in the liver through the kynurenine pathway. Increased levels of proinflammatory cytokines and cortisol increase the metabolism of tryptophan through the kynurenine pathway and reduce its availability for the synthesis of melatonin and serotonin, which may cause alterations in mood and sleep. The standardized saffron extract (affron) has shown beneficial effects on mood and sleep disorders in humans, but the underlying mechanisms are not well understood. Thus, the aim of this work was to study the effects of affronsupplementation on the kynurenine pathway and the synthesis of melatonin in rats. For this purpose, adult male Wistar rats were supplemented for 7 days with 150 mg/kg of affronor vehicle (2 mL/kg water) administered by gavage one hour before sleep. Affronsupplementation reduced body weight gain and increased the circulating levels of melatonin, testosterone, and c-HDL. Moreover, animals supplemented with affronshowed decreased serum levels of kynurenine, ET-1, and c-LDL. In the pineal gland, affronreducedexpression and increased the expression of, the key enzyme for melatonin synthesis. In the liver, affronadministration decreased the mRNA levels of the enzymes of the kynurenine pathway,, and, as well as the gene expression ofand. Finally, rats treated with affronshowed increased mRNA levels of the antioxidant enzymes,,, and, both in the liver and in the pineal gland. In conclusion, affronsupplementation reduces kynurenine levels and promotes melatonin synthesis in rats, possibly through its antioxidant and anti-inflammatory effects, making this extract a possible alternative for the treatment and/or prevention of mood and sleep disorders.