Radiomodulatory and free-radical scavenging activity of the fractionated aquo-alcoholic extract of the adaptogenic nutraceutical (Rhodiola imbricata)--a comparative in vitro assessment with ascorbate.

OBJECTIVE: Immense interest has been generated in recent years for the development of drugs of herbal origin for the mitigation of deleterious effects of environmental pollutants like ionizing radiation, mainly to protect against radiation leakages resulting from mishaps in nuclear reactors, deliberate use of dirty bombs, etc.
METHOD: The radio modifying effects of a fractionated extract of the high-altitude Himalayan plant species Rhodiola imbricata, along with its electron-donation potential, super-oxide ion scavenging (IC50 ≤ 0.025 mg/ml), nitric oxide (NO) scavenging potential (IC(50) = 0.5 mg/ml), and antihemolytic activity were evaluated in the present study. Reducing power, superoxide ion (O(2)(•-)), and nitric oxide scavenging ability of the fractionated extract increased in a dose-dependent manner. Rhodiola imbricata also exhibited antihemolytic potential preventing radiation-induced membrane degeneration of human erythrocytes.
CONCLUSION: Thus, it can be stated that Rhodiola imbricata provides protection against gamma radiation via multifarious mechanisms that act in a synergistic manner. Rhodiola imbricata is widely used as a nutraceutical supplement in the trans-Himalayan region nations, and the current study shows that Rhodiola has immense potential for alleviation of biological damage in a radiation environment.