Extracts of Black Glutinous Rice Influenced Memory Impairment and Anxiety-Like Behavior associated with Kidney Stones in Rats

This study investigated the effects of “Luem Pua” black glutinous rice extract on behavior and neuronal integrity by assessing memory impairment, anxiety-like behavior, histology, as well as expression of brain-derived neurotrophic factor (Bdnf) and caspase-3 (Casp3) genes in a rat model of kidney stone disease. Male Sprague-Dawley rats were divided into five groups (n=6): a control group, an ethylene glycol (EG)-induced kidney stone group, two EG groups receiving either a low or high dose of rice extract, and an anthocyanin-administered EG group. Memory impairment and anxiety-like behavior were assessed by applying the Morris Water Maze (MWM) and the open field test. Neuronal damage was determined using hematoxylin & eosin. Hippocampal Bdnf and Casp3 expression levels were ascertained using SYBR Green qPCR. The EG rats showed a significantly longer MWM escape latency and spent less time in the open field center than controls. However, low doses of rice extract or standard anthocyanin markedly reduced escape latency and enhanced the time spent in the center. Moreover, prefrontal pyknotic nuclei were increased in EG rats, a phenomenon suppressed by the two doses of rice extracts and anthocyanins. Casp3 gene expression was elevated in the EG group but declined after rice extract treatment. Bdnf expression did not alter remarkably. These findings suggest that a limited dose of black glutinous rice extract, as well as anthocyanin, alleviates memory impairment, anxiety-like behavior, and neuronal damage in a rat model of kidney stone disease.