Fractions of traditionally brewed rice beverage relieve anxiety and improve spatial memory in mice

Abstract

Rice beverages are traditionally prepared and consumed popularly by the different ethnic groups of North East India and claimed to have several health benefits. In an attempt to validate the traditional claims, effects of different fractions of the beverage were studied using mouse model. To investigate its effects on behavior, mice were treated with different fractions of rice beverage that included the beverage as a whole, insoluble and soluble fractions. Intragastric treatments of these fractions were given to the mice (n = 6 per group) for 30 days, and behavioral studies were performed on elevated plus and Y maze to evaluate anxiety and spatial memory, respectively. Next-generation sequencing of metagenomic DNA of the beverage indicated the presence of 157 OTUs, and 26 bacterial genera were dominant with an abundance of 0.1%. The insoluble fraction and the whole beverage treatments reduced the anxiety-like symptoms in animals indicating the probable role of microbes. Spatial memory improved in all the treatments compared to the control, of which the rice beverage treatment showed the highest levels (p < 0.05). Gas chromatography and mass spectroscopy-based metabolite profiling of the beverage revealed 10 alcohols, 29 sachharides, 43 acids, and 13 amino acids. Findings of this study suggest a positive effect of rice beverage on anxiety and spatial memory of mice, justifying the claims by ethnic communities on its role on mood regulation.