title: 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.
abstract: 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Nuclear Medicine and Allied Sciences, Delhi, India. rajesharoradr@rediffmail.com
authors.forename: Rajesh
authors.initials: R
authors.lastname: Arora
authors.forename: Shikha
authors.initials: S
authors.lastname: Singh
authors.forename: R K
authors.initials: RK
authors.lastname: Sagar
authors.forename: Raman
authors.initials: R
authors.lastname: Chawla
authors.forename: R
authors.initials: R
authors.lastname: Kumar
authors.forename: S C
authors.initials: SC
authors.lastname: Puri
authors.forename: S
authors.initials: S
authors.lastname: Surender
authors.forename: J
authors.initials: J
authors.lastname: Prasad
authors.forename: M L
authors.initials: ML
authors.lastname: Gupta
authors.forename: B
authors.initials: B
authors.lastname: Krishna
authors.forename: M S
authors.initials: MS
authors.lastname: Siddiqui
authors.forename: A K
authors.initials: AK
authors.lastname: Sharma
authors.forename: R P
authors.initials: RP
authors.lastname: Tripathi
authors.forename: G N
authors.initials: GN
authors.lastname: Qazi
authors.forename: Rakesh Kumar
authors.initials: RK
authors.lastname: Sharma
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D004912:Erythrocytes / Q000187:drug effects* / Q000528:radiation effects; D016166:Free Radical Scavengers / Q000494:pharmacology* / Q000627:therapeutic use; D005609:Free Radicals / Q000378:metabolism; D006401:Hematologic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D006801:Humans; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology* / Q000627:therapeutic use; D011832:Radiation Injuries / Q000097:blood / Q000517:prevention & control*; D011839:Radiation, Ionizing; D011837:Radiation-Protective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D029771:Rhodiola
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D006401:Hematologic Agents; D010936:Plant Extracts; D011837:Radiation-Protective Agents; D001205:Ascorbic Acid