Participation of the Serotonergic System and Brain-Derived Neurotrophic Factor in the Antidepressant-like Effect of Flavonoids.

Depressive disorders are among the most disabling diseases experienced around the world, and their incidence has significantly increased over the last few decades due to multiple environmental, social, and biological factors. The search for new pharmacological alternatives to treat depression is a global priority. In preclinical research, molecules obtained from plants, such as flavonoids, have shown promising antidepressant-like properties through several mechanisms of action that have not been fully elucidated, including crossing of the blood brain barrier (BBB). This review will focus on discussing the main findings related to the participation of the serotonergic system and brain-derived neurotrophic factor (BDNF) on the antidepressant-like effect of some flavonoids reported by behavioral, neurochemical, and molecular studies. In this sense, evidence shows that depressive individuals have low levels of serotonin and BDNF, while flavonoids can reverse it. Finally, the elucidation of the mechanism used by flavonoids to modulate serotonin and BDNF will contribute to our understanding of the neurobiological bases underlying the antidepressant-like effects produced by these natural compounds.

Effect of blackberry juice (Rubus fruticosus L.) on anxiety-like behaviour in Wistar rats.

The present study evaluated the effects of blackberry juice that is rich in different concentrations of anthocyanins and polyphenols (2.6 mg/kg anthocyanins, 14.57 mg/kg polyphenols; 5.83 mg/kg anthocyanins, 27.10 mg/kg polyphenols; 10.57 mg/kg anthocyanins, 38.40 mg/kg polyphenols) on anxiety-like behaviour in Wistar rats. The rats were treated with blackberry juice for 21 days and then tested in the elevated plus maze, locomotor activity test and forced swim test. The results were compared with a reference anxiolytic drug diazepam (2.0 mg/kg) and vehicle (8.7 ml/kg). The intermediate dose of blackberry juice exerted an anxiolytic-like effect that was similar to diazepam, without affecting locomotive activity. The low and high doses of blackberry juice exerted no significant effects on anxiety-like behaviour compared with vehicle. In the forced swim test, both the high and intermediate doses of blackberry juice reduced total immobility time, suggesting a protective effect against behavioural changes that are induced by acute stress. These findings suggest a potential therapeutic effect of blackberry juice on anxiety that is associated with a stressful event.

Behavioral Effect of Sterculia apetala Seed Oil Consumption in Male Zucker Rats.

Sterculia apetala (order: Malvales, family: Sterculiaceae) seed oil contains two cyclopropene fatty acids: sterculic and malvalic acid. Both positive and negative effects have been associated with the consumption of sterculic oil. In Mexico, S. apetala seeds are consumed after being boiled or roasted, used as chocolate flavoring, and utilized as animal fodder. Therefore, it is important to evaluate whether the consumption of this seed has a negative impact on the organism. The aim of this study was to evaluate the effect of administration of sterculic oil, during an 8-week period, on anxiety-like behavior and spontaneous locomotor activity in Zucker rats, analyzed through light/dark and open-field tests. The results showed that the consumption of sterculic oil decreased exploration latency in light/dark tests, which suggests an anxiolytic-like effect. Alterations in time spent on rearing and grooming were present in open-field tests, but this was not statistically significant, discarding nonspecific motor alterations. The alterations found in this study are possibly related to intrinsic obesity and metabolic complications present in the Zucker rat model, where leptin plays an important role in animal mood, more so than sterculic oil consumption.