EFFECTS OF COLUPULONE, A COMPONENT OF HOPS AND BREWERS-YEAST, AND CHROMIUM ON GLUCOSE-TOLERANCE AND HEPATIC CYTOCHROME-P450 IN NONDIABETIC AND SPONTANEOUSLY DIABETIC MICE

Brewers yeast contains factors that increase and decrease glucose tolerance. Hop components (lupulones) that adhere to yeast during the brewing process elicit a variety of biological effects including the induction of hepatic cytochrome P4503A. Colupulone was tested for its effects on glucose tolerance and cytochrome P450. Serum glucose levels 30 min after the injection of glucose were lowered by colupulone in nondiabetic Swiss-Webster mice, elevated in diabetic C57Bl/KSJ-db/db mice, and unaffected in nondiabetic C57Bl/KSJ+m/+m mice. Colupulone lowered hemoglobin glycation slightly in +m/+m mice but not in db/db mice. The cytochrome P450 system was highly induced by colupulone in both db/db and +m/+m mice. Chromium, which acts in concert with the factor in yeast that enhances glucose tolerance, had little or no effect on the plasma glucose level or the cytochrome P450 system in either +m/+m Or db/db mice. (C) 1994 Academic Press, Inc.