Effects of β-pinene,a nonsubstituted monoterpene,on rat liver mitochondria

β-Pinene uncouples oxidative phosphorylation and inhibits respiration in isolated rat liver mitochondria. The uncoupling effects are observed at lower concentrations (100 to 200 μM) than the inhibition of respiration (400 μM). At low concentrations, the effects observed could be explained by an increase of the passive permeability of the mitochondrial membrane produced by the terpene. Higher concentrations seemed to inhibit respiration through an effect on the electron transport chain. At the highest concentrations tested (600 to 1200 μM), β-pinene seemed to produce a partial resealing of the mitochondrial membrane. All effects can be explained by the interaction of β-pinene with the mitochondrial membrane. Other hydrophobic molecules tested do not show the effects of β-pinene or limonene on mitochondria.