Effect of GABA Extract of Black Sticky Rice with Giant Embryo on Alcohol-Related Indices After Acute Alcohol Intake in Social Drinkers

Background This study was performed to evaluate the effect and safety of a high‐gamma‐aminobutyric acid‐containing extract (GABA extract) of black sticky rice with giant embryo (BSRGE) on alcohol‐related indices after acute alcohol intake in social drinkers. Methods Subjects were randomized to the GABA extract (G) group, GABA extract and alcohol drinking (GA) group, or placebo intake and alcohol drinking (PA) group in a double‐blind design. All subjects were administered GABA extract (200 mg GABA) or placebo at 9 am on study days 2 and 3, respectively. Subjects in the GA and PA groups were administered an equivalent dose of alcohol that was diluted in a drinking beverage for a total amount of 240 ml at 11 am on day 3. Blood alcohol concentration (BAC) and the Biphasic Alcohol Effects Scale were measured just before alcohol drinking, and 6 times after alcohol drinking. Results The peak and area under the curve (AUC) of the total stimulation scale score after alcohol intake in females were significantly higher in the GA than in the PA group, whereas no significant difference was found between the 2 groups in males. The peak and AUC of the total score on the sedation scale after alcohol intake in males were significantly lower in the GA than in the PA group, whereas both were significantly higher in the GA than in the PA group of females. The AUC for BAC in males was significantly lower in the GA than in the PA group, whereas no significant difference was found in females. No adverse events were reported in any of the groups including the G group. Conclusions Coadministration of a GABA extract to social drinkers while drinking alcohol is supposed to affect alcohol‐related indices in terms of pharmacodynamics and pharmacokinetics and did not induce any adverse events.