Antigenotoxic effects of Satureja hortensis L. on rat lymphocytes exposed to oxidative stress.

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, 1.0, and 2.5 mg/ mL), essential oil (SHEO)(0.05, 0.1, 0.5, 1.0, and 2.5 microL/mL), H2O2 (50, 100, and 200 microM), a combination of H2O2 (200 mM) with either SHE (1.0, 2.5 mg/mL) or SHEO (1.0, 2.5 microL/mL) at 4 degrees C for 30 min, and 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 (1.0 and 2.5 microL/mL) also showed significant inhibitory effects (P < 0.01) on H2O2 induced chromosomal damage. In conclusion both the ethanolic extract and the essential oil of the plant reversed the oxidative damage to rat lymphocytes induced by hydrogen peroxide.