title: Water extracts of tree Hypericum sps. protect DNA from oxidative and alkylating damage and enhance DNA repair in colon cells.
abstract: Diet may induce colon carcinogenesis through oxidative or alkylating DNA damage. However, diet may also contain anticarcinogenic compounds that contribute to cancer prevention. DNA damage prevention and/or induction of repair are two important mechanisms involved in cancer chemoprevention by dietary compounds. Hypericum sps. are widely used in traditional medicine to prepare infusions due to their beneficial digestive and neurologic effects. In this study, we investigated the potential of water extracts from three Hypericum sps. and some of their main phenolic compounds to prevent and repair oxidative and alkylating DNA damage in colon cells. The results showed that water extracts of Hypericum perforatum, Hypericum androsaemum, Hypericum undulatum, quercetin and rutin have protective effect against oxidative DNA damage in HT29 cells. Protective effect was also observed against alkylating DNA damage induced by methyl-methanesulfonate, except for H. androsaemum. With regard to alkylating damage repair H. perforatum, H. androsaemum and chlorogenic acid increased repair of alkylating DNA damage by base excision repair pathway. No effect was observed on nucleotide excision repair pathway. Antigenotoxic effects of Hypericum sps. may contribute to colon cancer prevention and the high amount of phenolic compounds present in Hypericum sps. play an important role in DNA protective effects.
authors.affiliation: CBMA - Centre of Molecular and Environmental Biology, Department of Biology, School of Sciences, University of Minho, 4710-057 Braga, Portugal.
authors.forename: Alice A
authors.initials: AA
authors.lastname: Ramos
authors.forename: Filipe
authors.initials: F
authors.lastname: Marques
authors.forename: Manuel
authors.initials: M
authors.lastname: Fernandes-Ferreira
authors.forename: Cristina
authors.initials: C
authors.lastname: Pereira-Wilson
mesh_terms: D000477:Alkylating Agents / Q000009:adverse effects; D003106:Colon / Q000166:cytology / Q000187:drug effects*; D004249:DNA Damage / Q000187:drug effects; D004260:DNA Repair / Q000187:drug effects*; D019073:HT29 Cells / Q000187:drug effects; D006801:Humans; D020902:Hypericum / Q000737:chemistry*; D009152:Mutagenicity Tests; D018384:Oxidative Stress / Q000187:drug effects; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry; D020011:Protective Agents / Q000494:pharmacology*; D011794:Quercetin / Q000494:pharmacology; D012431:Rutin / Q000494:pharmacology
chemical_list: D000477:Alkylating Agents; D010936:Plant Extracts; D020011:Protective Agents; D012431:Rutin; D011794:Quercetin