Inhibition of heat shock-induced apoptosis by peppermint oil in astrocytes.

Exposure to environmental stresses and toxins is linked to the pathogenesis of neuropsychiatric disorders. Astrocytes, the most abundant glial-cell type in the brain, are considered to have physiological and pathological roles in neuronal activities. We have investigated whether peppermint oil inhibits heat shock-induced apoptosis of astrocytes. We found that peppermint oil inhibits the heat shock-induced apoptosis in both human astrocyte CCF-STTG1 cells and rat astrocytes. Pretreatment of the cells with peppermint oil inhibited the heat shock-induced DNA fragmentation and condensation of nuclear chromatin. Peppermint oil also inhibited the caspase-3 activation and poly-ADP-ribose polymerase fragmentation in CCF-STTG1 cells. These results suggest that peppermint oil may modulate the apoptosis of astrocytes via the activation of the caspase-3.