title: Geraniin down regulates gamma radiation-induced apoptosis by suppressing DNA damage.
abstract: Gamma ray irradiation triggers DNA damage and apoptosis of proliferating stem cells and peripheral immune cells, resulting in the destruction of intestinal crypts and lymphoid system. Geraniin is a natural compound extracts from an aquatic plant Nymphaea tetragona and possesses good antioxidant property. In this study, we demonstrate that geraniin rescues radiosensitive splenocytes and jejunal crypt cells from radiation-induced DNA damage and apoptosis. Isolated splenocytes from C57BL/6 mice treated with geraniin were protected against radiation injury of 2 Gy irradiation through the enhancement of the proliferation and attenuation of DNA damage. Also, geraniin inhibited apoptosis in radiosensitive splenocytes by reducing the expression level and immunoreactivity of proapoptotic p53 and Bax and increasing those of anti-apoptotic Bcl-2. In mice exposed to radiation, geraniin treatment protected splenocytes and intestinal crypt cells from radiation-induced cell death. Our results suggest that geraniin presents radioprotective effects by regulating DNA damage on splenocytes, exerting immunostimulatory capacities and inhibiting apoptosis of radiosensitive immune cells and jejunal crypt cells. Therefore, geraniin can be a radioprotective agent against γ-irradiation exposure.
authors.affiliation: Department of Veterinary Medicine and Applied Radiological Science Research Institute, Jeju National University, Ara-dong 1, Jeju 690-756, South Korea.
authors.forename: So Jin
authors.initials: SJ
authors.lastname: Bing
authors.forename: Danbee
authors.initials: D
authors.lastname: Ha
authors.forename: Min Ju
authors.initials: MJ
authors.lastname: Kim
authors.forename: Eunjin
authors.initials: E
authors.lastname: Park
authors.forename: Ginnae
authors.initials: G
authors.lastname: Ahn
authors.forename: Dae Seung
authors.initials: DS
authors.lastname: Kim
authors.forename: Ryeo Kyeong
authors.initials: RK
authors.lastname: Ko
authors.forename: Jae Woo
authors.initials: JW
authors.lastname: Park
authors.forename: Nam Ho
authors.initials: NH
authors.lastname: Lee
authors.forename: Youngheun
authors.initials: Y
authors.lastname: Jee
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects; D005720:Gamma Rays; D016158:Genes, p53; D005960:Glucosides / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D047348:Hydrolyzable Tannins / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D007274:Injections, Intraperitoneal; D007421:Intestine, Small / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D007583:Jejunum / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D030721:Nymphaea / Q000737:chemistry; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011839:Radiation, Ionizing; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D023382:Toxicity Tests, Acute; D014916:Whole-Body Irradiation; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C494827:Bax protein, mouse; D005960:Glucosides; D047348:Hydrolyzable Tannins; D019253:Proto-Oncogene Proteins c-bcl-2; D011837:Radiation-Protective Agents; D051028:bcl-2-Associated X Protein; C024603:Geraniin