In Vitro Protective Effects of Aqueous and Alcoholic Extracts of Caryophyllus aromaticus on Reducing H2O2-Induced DNA Damage in Human Mononuclear White Blood Cells

This study aimed to investigate the protective effects of aqueous and ethanolic extracts of Caryophyllus aromaticus on DNA damage in mononuclear white cells of human blood using the COMET method.

Mononuclear white blood cells were isolated from blood samples taken from 15 healthy volunteers. Cells were treated with H2O2 (25, 50, 100, and 200 μM), as well as with aqueous and ethanolic extracts of aerial parts of cloves (0.05, 0.1, 0.5, 1, and 2.5 mg/ml). Finally, to induce DNA damage the cells were incubated in a combination of 100 μM H2O2 with each of the two aqueous and alcoholic extracts at a concentration of 2.5 mg/ml at 4°C for 30 minutes. The extent of DNA migration was measured using the alkaline single cell gel electrophoresis approach assay, and DNA damage was expressed as tail length (µm), percentage of tail DNA, and tail moment (µm).

DNA damage in the mononuclear white blood cells exposed to the combination of hydrogen peroxide with aqueous extract of clove plant was significantly less than that in the mononuclear white blood cells treated with H2O2 alone. Tail length (µm) was 5.30±1.21 versus 21.84±3.91, percentage of tail DNA (%) was 4.29±1.21 versus 16.21±4.18, and tail movement (µm) was 0.24±0.08 versus 2.35±0.72, respectively (p < 0.001).

The results showed that the aqueous extract of clove plant (2.5 mg/ml) can prevent oxidative DNA damage in human mononuclear white blood cells, which is probably due to the presence of antioxidant compounds in the extract.