Premium
Protection from radiation‐induced mitochondrial and genomic DNA damage by an extract of Hippophae rhamnoides
Author(s) -
Shukla Sandeep Kumar,
Chaudhary Pankaj,
Kumar Indracanti Prem,
Samanta Namita,
Afrin Farhat,
Gupta Manju Lata,
Sharma Upendra Kumar,
Sinha Arun Kumar,
Sharma Yogendra Kumar,
Sharma Rakesh Kumar
Publication year - 2006
Publication title -
environmental and molecular mutagenesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1
H-Index - 87
eISSN - 1098-2280
pISSN - 0893-6692
DOI - 10.1002/em.20251
Subject(s) - chemistry , dna damage , microbiology and biotechnology , dna , mitochondrial dna , biochemistry , gene , biology
Abstract Hippophae rhamnoides or seabuckthorn is used extensively in Indian and Tibetan traditional medicine for the treatment of circulatory disorders, ischemic heart disease, hepatic injury, and neoplasia. In the present study, we have evaluated the radioprotective potential of REC‐1001, a fraction isolated from the berries of H. rhamnoides. Chemical analysis of the extract indicated that REC‐1001 was ∼68% by weight polyphenols, and contained kaempferol, isorhamnetin, and quercetin. The effect of REC‐1001 on modulating radiation‐induced DNA damage was determined in murine thymocytes by measuring nonspecific nuclear DNA damage at the whole genome level using the alkaline halo assay and by measuring sequence/gene‐specific DNA damage both in nuclear DNA (β‐globin gene) and in mitochondrial DNA using a quantitative polymerase chain reaction. Treatment with 10 Gy resulted in a significant amount of DNA damage in the halo assay and reductions in the amplification of both the β‐globin gene and mitochondrial DNA. REC‐1001 dose‐dependently reduced the amount of damage detected in each assay, with the maximum protective effects observed at the highest REC‐1001 dose evaluated (250 μg/ml). Studies measuring the nicking of naked plasmid DNA further established the radioprotective effect of REC‐1001. To elucidate possible mechanisms of action, the antioxidant properties and the free‐radical scavenging activities of REC‐1001 were evaluated. REC‐1001 dose‐dependently scavenged radiation‐induced hydroxyl radicals, chemically‐generated superoxide anions, stabilized DPPH radicals, and reduced Fe 3+ to Fe 2+ . The results of the study indicate that the REC‐1001 extract of H. rhamnoides protects mitochondrial and genomic DNA from radiation‐induced damage. The polyphenols/flavonoids present in the extract might be responsible for the free radical scavenging and DNA protection afforded by REC‐1001. © 2006 Wiley‐Liss, Inc.