Suppressive effect of ethyl acetate extract of Teucrium polium on cellular oxidative damages and apoptosis induced by 2-deoxy-d-ribose: Role of de novo synthesis of glutathione

The effect of ethyl acetate (EtOAc) extract of Teucrium polium on 2-deoxy-d-ribose (dRib)-induced oxidative stress and apoptosis in erythroleukemic K562 cells was investigated. K562 cells exposed to dRib (50 mM) exhibited abnormal properties such as overproduction of reactive oxygen species, lipid peroxidation, glutathione (GSH) depletion and biochemical features of apoptosis. Treatment with EtOAc extract (25 and 50 μg/ml) reduced oxidative stress and apoptosis among the dRib-treated K562 cells. To disclose the mode of action, the effect of the extract on the cellular GSH and its synthesis by γ-glutamylcysteine synthetase (γ-GCS), a key rate-limiting enzyme of the GSH synthetic pathway, were evaluated. The results demonstrated that the antioxidant property of EtOAc extract mainly results from increasing the level of cellular GSH by inducing the activity of γ-GCS. It can be concluded that the EtOAc extract of T. polium prevents dRib-induced oxidative stress and apoptosis mostly through antioxidative mechanisms.