Protection against radiation-induced oxidative damage by an ethanolic extract of Nigella sativa L.
OBJECTIVE
An ethanolic extract of Nigella sativa L. (EE-NS) was investigated for its antioxidant properties and radioprotective effects against gamma-radiation-induced oxidative damage.


METHODS
The radical scavenging activity of the extract was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH), deoxyribose degradation and plasmid relaxation assays in a cell-free system. DNA damage studies were performed using a single cell gel electrophoresis (SCGE) assay and micronuclei (MN) formation. Moreover, the alterations in lipid peroxidation and antioxidant enzymes were measured by biochemical methods.


RESULTS
EE-NS showed significant free radical scavenging and protection against DNA damage in cell free systems. Ex vivo treatment of mouse splenic lymphocytes with an ethanolic extract of N. sativa 1 h prior to irradiation (2 Gy) showed significant prevention of the formation of lipid-peroxides and intracellular reactive oxygen species (ROS), which correlated with radiation-induced apoptosis. Moreover, radiation-induced DNA damage was significantly prevented in splenocytes pre-treated with EE-NS. Swiss albino mice fed orally with the different doses of EE-NS (0-100 mg/kg bw) for five consecutive days followed by 2 Gy whole body irradiation (WBI) showed significant protection against oxidative injury to spleen and liver as measured by lipid peroxidation and the activity of antioxidant enzymes. These results were correlated with the prevention of DNA damage as measured by bone marrow micronuclei assay. Our results suggest that oral feeding of extract resulted in increased survival in mice exposed to WBI (7.5 Gy).


CONCLUSIONS
The results obtained from the different experimental systems suggest the radioprotective ability of EE-NS involving prevention of radiation-induced oxidative damage.
Rastogi
Lori
L
Radiation Biology and Health Sciences Division, Bhabha Atomic Research Center, Mumbai, India.
Feroz
Shaikh
S
Pandey
Badri Narain
BN
Jagtap
Arti
A
Mishra
Kaushala Prasad
KP
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D002474:Cell-Free System; D004249:DNA Damage; D005260:Female; D016166:Free Radical Scavengers / Q000494:pharmacology; D007958:Leukocyte Count; D015227:Lipid Peroxidation / Q000187:drug effects; D051379:Mice; D031881:Nigella sativa; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000494:pharmacology*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D014916:Whole-Body Irradiation
D000975:Antioxidants; D016166:Free Radical Scavengers; D010936:Plant Extracts; D011837:Radiation-Protective Agents