Diets enriched with a Jerte Valley cherry-based nutraceutical product reinforce nocturnal behaviour in young and old animals of nocturnal ("Rattus norvegicus") and diurnal ("Streptopelia risoria") chronotypes

Abstract

The decline in melatonin secretion with age seems to be one of the major reasons for increased sleep disruption in older animals. Previously, we showed that the administration with melatonin or its precursor, tryptophan, improved activity/rest rhythms in aged individuals. Here, it was evaluated the effect of a 10-day consumption of a Jerte Valley cherry-based nutraceutical product (patent no. ES2342141B1), which contains high levels of tryptophan, serotonin and melatonin, on the activity/rest rhythms of young and old rats (Rattus norvegicus) and ringdoves (Streptopelia risoria) as representatives of animals with nocturnal and diurnal habits, respectively, and its possible relationship with the serum levels of melatonin and glucose. Total diurnal and nocturnal activity pulses were logged at control, during, and up to 3 days after the treatment. Melatonin and glucose were measured with ELISA and testing kits respectively. In both young and old rats, the intake of the cherry nutraceutical decreased diurnal activity, whereas nocturnal activity increased. The opposite effect was observed for ringdoves. The treatment increased the circulating levels of melatonin in both species and restored the amplitude of the activity rhythm in the old animals to that of the non-treated young groups. The consumption of a Jerte Valley cherry-based nutraceutical product may help to counteract the impaired activity/rest rhythm found in aged animals.