Abstract

The damaging effect of ionizing radiation on body systems on one hand, and the development of radio-protective agents on the other hand, have gained increased attention in the last decades. In the present study, male Swiss albino mice exposed to six gray gamma irradiation, exhibited significant increase in brain thiobarbituric acid reactive substances (TBARS), nitric oxide (NO), and free radicals such as hydrogen peroxide (H₂O₂). Significant decrease in the levels of reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) contents, acetylcholinestrase (AchE), and the neurotransmitters dopamine (DA), serotonin (5-HT), and acetylcholine (Ach), was also documented. In addition, the levels of serum electrolytes sodium (Na), calcium (Ca), zinc (Zn), magnesium (Mg), and cupper (Cu) decreased significantly, while the levels of potassium (K), and iron (Fe) increased significantly. Additionally, some Lewy body aggregations were detected. On the other hand, pretreatment of gamma irradiated mice with Mentha piperita extract (1g /1Kg body weight /day) significantly abolished radiation induced elevations of TBARS, NO, H₂O₂, K and Fe levels, as well as significantly ameliorated the GSH, GST, SOD, AchE, DNA, RNA, Na, Ca, Zn, Mn, Cu and the mentioned-above neurotransmitters levels. In conclusion, Mentha extract may provide a significant level of protection against radiation-induced oxidative stress. It might have improved the antioxidant defense system in pre-treated mice also.

Key words: Gamma irradiation, Mentha piperita, oxidative stress, neuroprotective radioprotective agent, endogenous antioxidant system.

Abbreviation

Ach, Acetylcholine;  AChE, Acetylcholinestrase; DNA, Deoxyribonucleic Acid; DA, Dopamine; GSH, Glutathione; GST, Glutathione-S-transferase; Gy, Gray; Hydrogen peroxide; LB, Lewy bodies; MDA, Malondialdehyde; NO, Nitric oxide; ROS,Reactive oxygen species; RNA, Ribonucleic Acid; 5-HT, Serotonin;  SNc, Substantia nigra compacta; SOD, Superoxide dismutase; TBARS, Thiobarbituric acid reactive substances.