Water-insoluble fractions of botanical foods lower blood ethanol levels in rats by physically maintaining the ethanol solution after ethanol administration

Abstract

Background: Several studies have analyzed the functions of foods and dietary constituents in the dynamics of alcohol metabolism. However, few studies have reported the function of dietary fibers in the dynamics of alcohol metabolism.Objective: We assessed the effects of botanical foods that contain dietary fibers on alcohol metabolism.Methods: The ability of the water-insoluble fraction (WIF) of 18 kinds of botanical foods to maintain 15% (v/v) ethanol solution was examined using easily handled filtration. A simple linear regression analysis was performed to examine the correlation between the filtered volumes and blood ethanol concentration (BEC) in F344 rats 4 h after the ingestion of 4.0 g/kg of ethanol following dosage of 2.5% (w/v) WIF of the experimental botanical foods. Furthermore, the supernatant (6.3 Brix; water-soluble fraction) and precipitate (WIF of tomato), with a strong ethanol-maintaining ability, were obtained and BEC and the residual gastric ethanol in rats were determined 2 h after the administration of 4.0 g/kg of ethanol and the individuals fractions.Results: The filtered volumes of dropped ethanol solutions containing all the botanical foods tested except green peas were decreased compared with the ethanol solution without WIF (control). There was a significant correlation between the filtered volumes and blood ethanol concentration (BEC). There was no significant difference in the residual gastric ethanol between controls and the supernatant group; however, it was increased significantly in the WIF group than in controls or the supernatant group. Consistent with this, BEC reached a similar level in controls and the supernatant group but significantly decreased in the WIF group compared with controls or the supernatant group.Conclusions: These findings suggest that WIFs of botanical foods, which are mostly water-insoluble dietary fibers, possess the ability to absorb ethanol-containing solutions, and this ability correlates strongly with the inhibition of the blood ethanol response, likely by delaying gastric emptying.Key words: Botanical food, tomato, water-insoluble fraction, dietary fiber, blood ethanol concentration