In vitro Protective Effects of Satureja hortensis L. Essential Oil and Ethanolic Extract on Lymphocytes DNA

DNA damage and oxidative stress are widely recognized as major factors in many degenerative diseases and aging. The protective properties of Satureja hortensis L. on the rat lymphocytes DNA lesions were tested. Lymphocytes were isolated from blood samples taken from healthy rats. DNA breaks and resistance to H2O2-induced damage were measured with the comet assay. Rat lymphocytes were incubated in S. hortensis ethanolic extract (SHE) (0.05, 0.1, 0.5, 1 and 2.5 mg/ml), essential oil (SHEO) (0.05, 0.1, 0.5, 1 and 2.5 µl/ml), H2O2 (50, 100 and 200 µM), a combination of H2O2 (200 M) with either SHE (1, 2.5 mg/ml) or SHEO (1, 2.5 µl/ml) at 4oC for 30 minutes. The extent of DNA migration was measured using a single-cell microgel electrophoresis technique under alkaline conditions. Treatment of rat lymphocytes with SHE or SHEO resulted in significant reduction of H2O2-induced DNA damage compared to controls. SHE exhibited a significant (p<0.01) inhibitory effect on oxidative DNA damage at 2.5 mg/ml. SHEO (1 and 2.5 µl/ml) also showed significant inhibitory effects (p <0.01) on H2O2 induced chromosomal damage. Both the ethanolic extract and the essential oil of the plant were able to reverse the oxidative damage on rat lymphocytes induced by hydrogen peroxide.