Hippophae Leaf Extract Concentration Regulates Antioxidant and Prooxidant Effects on DNA

• Published in: Journal of dietary supplements 2010-03, Vol.7 (1), p.60-70
• Main Authors: Saini, Manu, Tiwari, Sandhya, Prasad, Jagdish, Singh, Surender, Kumar, M. S. Yogendra, Bala, Madhu
• Format: Article
• Language: English
• Subjects: Animals; antioxidant effect; Antioxidants - pharmacology; Base Composition; Biological and medical sciences; Dietary Supplements; DNA - drug effects; DNA Damage; Dose-Response Relationship, Drug; Food industries; Free Radical Scavengers - pharmacology; free radical scavenging; Fundamental and applied biological sciences. Psychology; Genome - drug effects; Hippophae; Hippophae - chemistry; Humans; Hydroxyl Radical - metabolism; Liver; Mice; Oxidants - adverse effects; Plant Extracts - adverse effects; Plant Extracts - chemistry; Plant Extracts - pharmacology; Plant Leaves; prooxidant effect; Quercetin - pharmacology; Radiation-Protective Agents; Research and development. New food products, dietetic foods and beverages; Saccharomyces cerevisiae; Trace Elements; Vitaceae
• ISSN: 1939-0211; 1939-022X
• DOI: 10.3109/19390210903535027

Extracts from Hippophae leaves constitute some commonly consumed beverages such as tea and wine. We had developed an extract of Hippophae leaves (SBL-1), which was rich in quercetin, had antimutagenic effects, radioprotective effects, and countered radiation-induced gene conversion in Saccharomyces cerevisiae. This study was designed to investigate the action of SBL-1 on guanine cytosine (GC)-rich nascent and mouse genomic DNA in vitro. The human and mouse liver DNA have about 43% GC content. Our results showed that at small concentration SBL-1 protected nascent as well as genomic DNA, while at large concentration SBL-1 damaged both types of DNA. The concentration of SBL-1 that protected DNA also demonstrated higher free radical scavenging activity. The reducing power of SBL-1 was greater than its free radical scavenging activity. The greater reducing power may have reduced the trace metals present in the SBL-1, leading to generation of hydroxyl radicals via Fenton reaction. The increased proportion of unscavenged hydroxyl radicals with increase in SBL-1 concentration may have been responsible for DNA damage or prooxidant effect of SBL-1 in vitro. This study suggests that the dietary supplements prepared from Hippophae should have low metal content.