ACCELERATION OF THE ALCOHOL OXIDATION RATE IN RATS WITH ALOIN, A QUINONE DERIVATIVE OF ALOE

Aloe contains abundant aloin, a C-glycoside derivative of anthraquinon e. Based on recent reports indicating that the water extract of Aloe e nhances the ethanol oxidation rate and also that quinones, in general, have a functional role in elevating the alcohol oxidation rate in viv o, we have attempted to identify the quinone derivative contained in A loe that could increase the alcohol oxidation rate. Upon oral administ ration of aloin (300 mg/kg) given 12 hr prior to the administration of alcohol (3.0 g/kg), the blood alcohol area under tile curve (AUG) was found to be decreased significantly (by 40%). This was supported by i ncreases in the rates of blood alcohol elimination and the disappearan ce of alcohol from the body by 45 and 50%, respectively. Analysis of h epatic triglyceride (TG) levels revealed that both the ethanol and the aloin treatment alone significantly increased the TG levels in a comp arable manner; however, the level obtained by the combined treatment o f aloin and ethanol was not statistically different from that produced by either treatment alone. The levels of serum L-aspartate:2-oxogluta rate aminotransferase (AST) and L-alanine:2-oxoglutarate aminotransfer ase (ALT) activities were not increased by acute alcohol intoxication, aloin alone, or by the combined treatment of alcohol and aloin. Pretr eatments with aloe-emodin, the anthraquinone aglycone of aloin, result ed in a significantly decreased blood alcohol AUC and an increase in t he rate of ethanol disappearance. These results suggested that when th e aloin localized primarily in the skin of Aloe is ingested, aloe emod in (the quinone aglycone) may be released, and the released quinone ma y produce acceleration oi the ethanol metabolism rate in vivo. Copyrig ht (C) 1996 Elsevier Science Inc.