Antiproliferative activity of Copaifera duckei oleoresin on liver regeneration in rats.

Copaiba oleoresin is widely used in folk medicine as an antiinflammatory, healing and antiseptic agent. Wistar rats received Copaifera duckei oleoresin (CDO) or saline solution (SS) from 7 days before surgery until killing. Partial hepatectomy (PH) or sham-operation was performed. Hepatocellular proliferation and liver mitochondrial respiration were evaluated 24 h after the procedure. The proliferating cell nuclear antigen labelling index was significantly lower in CDO-treated plus PH rats than in SS-treated plus PH rats, suggesting that CDO inhibited cell proliferation. The state 3 and state 4 respiration rates were greater for CDO-treated groups, and the stimulation of state 4 respiration was more expressive. These data resulted in a significant decrease in the respiratory control ratio observed for CDO-treated groups, demonstrating the ability of CDO to uncouple oxidative phosphorylation in mitochondria, a fact that may be one explanation for the inhibition of hepatocellular proliferation observed in the CDO-treated plus PH group. Copyright 2004 John Wiley & Sons, Ltd.