Rosemary extract and carnosol stimulate rat liver glutathione-S-transferase and quinone reductase activities.

The effects of dietary intake and intraperitoneal (i.p.) administration of an extract of the spice rosemary and of the rosemary constituent carnosol on the liver activities of glutathione-S-transferase (GST) and NAD(P)H-quinone reductase (QR) in the female rat were evaluated. Rosemary extract at concentrations from 0.25 to 1.0% (by wt.) in the diet resulted in a significant 3.5- to 4.5-fold increase in liver GST and a 3.3- to 4.0-fold increase in liver QR activities compared to controls. Carnosol supplemented in the diet at levels from 0.01 to 1.0% did not enhance GST activity. When rosemary extract and carnosol were administered i.p. there was a significant increase in liver GST and QR activities. The injection of rosemary extract (200 mg/kg) was associated with 1.5-fold and 3.2-fold increases in GST and QR activities, respectively, compared to controls. The injection of carnosol at doses from 100 to 400 mg/kg was associated with 1.6- to 1.9-fold increases in GST activity and 3.1- to 4.8-fold increases in QR activity, compared to controls. These data indicate that rosemary extract in the diet or injected i.p. and carnosol administered i.p. are effective enhancers of the in vivo activity of liver GST and QR in the female rat.