Divalent cations and radiation induced lipid peroxidation

Response of Co2+, Cu2+, Fe2+, Ni2+ and Mn2+ against radiation induced lipid peroxidation has been examined. Liposomes prepared from L-alpha-lecithin were irradiated with or without divalent cations, Co2+ and Cu2+ inhibited lipid peroxidation in concentration dependent manner. On the other hand Fe2+, Ni2+ and Mn2+ enhanced the peroxidation. The enhancement of peroxidation due to Ni2+ was biphasic in nature. Higher concentration of Mn2+ decreased the peroxidation. Except Cu2+ no other cation studied could change the non-linear pattern of radiation induced lipid peroxidation. The pro- or antioxidant effect of divalent cations may be due to their reactivity towards oxygen and oxygen free radicals, and at least in part to their hard/soft acid character.