Assessment of the Potential Impact of Aqueous and Ethanolic Malt Extracts on HepG2 Liver Cells.

RESEARCH

BACKGROUND

Malt is the second most abundant raw material in beer production and the main source of phenolic compounds. However, information on the specific contribution of different types of malt to the biological activity of beer and their effects on liver function remains limited. Therefore, this study aims to evaluate the antioxidant potential and effects on liver function of a Portuguese craft beer (imperial stout, IS-N) and the aqueous and ethanolic extracts of the malts present in IS-N beer (Carafa III, Caramunich III, Carapils and Pilsner).

EXPERIMENTAL APPROACH: Aqueous and ethanolic extracts of malt were obtained by solid-liquid extraction at a ratio of 1 g of powder to 9 mL of distilled water and 1 g of powder to 10 mL of φ(ethanol)=95 %, respectively. Total phenolic content (TPC) was determined by the Folin-Ciocalteu method, and antioxidant activity was evaluated by ABTS, DPPH and metal chelating capacity (ferrozine) assays. Cytotoxicity was evaluated in HepG2 cells using the MTT assay after exposing the cells to different concentrations of the samples (1-500 µg/mL) for 24 and 48 hours. Liver function was evaluated by determining alanine aminotransferase (ALT) activity in the cell supernatant.

RESULTS AND

CONCLUSIONS

TPC values, expressed as gallic acid equivalents (GAE), ranged from (7.1±0.5) to (28.2±0.5) mg/g, with the aqueous extract of Caramunich III ((23.6±0.6) mg/g) standing out for its high TPC and greater antioxidant capacity (IC50 ABTS=(17.3±0.8) µg/mL and IC50 DPPH=(152.6±9.3) µg/mL). Malt extracts showed no cytotoxicity up to 250 µg/mL, while IS-N beer with 8.5 % ethanol showed cytotoxicity at 500 µg/mL after 24 hours. IS-N beer induced lower ALT amounts than single malts, suggesting a possible synergistic effect between its bioactive compounds. Thus, evaluating the biological activity of malts could contribute to the production of beers with a better functional profile and reduced hepatic impact.

NOVELTY AND SCIENTIFIC CONTRIBUTION: This study breaks new ground by exploring the role of malts in the antioxidant activity and hepatic effects of craft beer, providing new data that could guide the development of beverages with a functional profile that is more beneficial to health.