Influence of Whisky Congeners on Health - The Institute of Brewing ...

When oolong tea or green tea was added as a non-alcoholic,
plant-compound-containing beverage, the enzyme activity was reduced by 55% or 54%,
respectively. Those findings indicated that whisky was more potent in inhibitory
activity than non-alcoholic beverages as well (data not shown).
When 10 μL <strong>of</strong> malt whisky <strong>of</strong> 5, 10, 15, 20, or 30 years <strong>of</strong> age was added to 1 mL <strong>of</strong>
the AR enzyme reaction reagent, AR’s activity was suppressed by 20%, 32%, 33%,
42%, or 56%, respectively, demonstrating that the inhibitory activity increased in
proportion to the age <strong>of</strong> the whisky (Fig 9). These findings suggested that the AR
inhibiting substances in whisky were oak compounds derived from the cask.
To evaluate the AR inhibitory compounds from whisky congener, a systematic
fractionation was carried out and their effects on hrAR were tested. The n-BuOH
fraction was found to exhibit the strongest AR inhibitory activity, its IC50 being 1.5
mg/L. An active principle as a potent AR inhibitor was isolated from this active
n-BuOH fraction and its chemical structure was identified as ellagic acid by spectral
analysis and comparing it with published data in the literature. Ellagic acid exhibited a
significant inhibition <strong>of</strong> AR in concentration-dependent manner, its IC50 value being
0.067 mg/L. The potency <strong>of</strong> this compound appeared equal to that <strong>of</strong> the known ARI,
ONO-2235 (Epalrestat) (data not shown).
Sorbitol was accumulated in erythrocytes when they were incubated in the medium
containing 30mM glucose. In the presence <strong>of</strong> ellagic acid, sorbitol accumulation was
inhibited in a dose-dependent manner (Fig. 10). At 100 mg/L, sorbitol accumulation
was inhibited by 70 %. In comparison with ONO-2235, which exhibits an IC50 <strong>of</strong>
1.5×10 -6 M, ellagic acid was less potent.
Although less potent than drugs, the specific activity <strong>of</strong> whisky congeners against AR
belongs to the most potent class for foods and beverages including alcoholic drinks. We
are evaluating the AR inhibiting activity <strong>of</strong> ellagic acid metabolites now.