Background: Queen bee acid (QBA; 10-hydroxy-2-decenoic acid) is the predominant fatty acid in royal jelly (RJ) and has activity at estrogen receptors, which affect brain function and body composition. However, few, long-term studies have assessed QBA effects in brain health and body composition.
Methods: Primary hippocampal neurons were treated with QBA (0-30 µM) and challenged with glutamate or hypoxia. QBA was fed to aged, male Sprague-Dawley rats (12-24 mg/kg/day) and to adult male and female Balb/C mice (30-60 mg/kg/day) for ≥3.5 months. Rats were evaluated in a behavioral test battery of brain function. Mice were measured for fat and muscle composition, as well as bone density.
Results: QBA increased neuron growth and protected against glutamate challenge and hypoxia challenge. Rats receiving QBA had reduced anxiety-like behavior, increased body weight, and better maintenance of body weight with age. Mice receiving QBA exhibited increased body weight, muscle mass, and adiposity in males, and increased bone density, but decreased adiposity, in females.
Conclusions: QBA is an active component of RJ that promotes the growth and protection of neurons, reduces anxiety-like phenotypes, and benefits bone, muscle and adipose tissues in a sex-dependent manner, which further implicates estrogen receptors in the effects of QBA.
Keywords: behavior; body composition; mood; neuroprotection; queen bee acid.