Protection of cellular DNA and membrane from γ-radiation-induced damages and enhancement in DNA repair by sesamol.

Sesamol (SM), a nutritional phenolic antioxidant compound present in sesame seeds, protected pBR 322 DNA from gamma radiation-induced damages. SM prevented gamma radiation-induced degradation of covalently closed circular form of plasmid DNA in a concentration-dependent manner. Also SM protected cellular DNA of mouse blood leukocytes exposed to 4 Gy gamma radiation, ex vivo, as revealed by the data from alkaline comet assay studies. SM (5 mM) showed a faster time-dependant decrease of the radiation-induced DNA damage in mouse blood leukocytes following postirradiation incubation ex vivo, which could be attributed to enhanced DNA repair. SM protected the biomembranes from radiation-induced lipid peroxidation. Thus, SM could act as a radioprotector for the biomembranes and cellular DNA against the deleterious effects of ionizing radiation.