title: Apigenin, a bioactive flavonoid from Lycopodium clavatum, stimulates nucleotide excision repair genes to protect skin keratinocytes from ultraviolet B-induced reactive oxygen species and DNA damage.
abstract: In this study, we examined the antioxidative and the DNA protective potentials of apigenin, a flavonoid polyphenol isolated from Lycopodium clavatum, in both in-vitro (HaCaT skin keratinocytes) and in-vivo (mice) models against UV-B radiation. We used DAPI staining in UV-B-irradiated HaCaT skin keratinocytes pre-treated with and without apigenin to assess DNA damage. We also used a flow-cytometric analysis in mice exposed to UV-B radiation with or without topical application of apigenin to assess, through a comet assay, chromosomal aberrations and quanta from reactive oxygen species (ROS) generation. Data from the stability curves for the Gibb's free energy determined from a melting-temperature profile study indicated that apigenin increased the stability of calf thymus DNA. Immunofluorescence studies revealed that apigenin caused a reduction in the number of cyclobutane pyrimidine dimers (CPDs) after 24 h, the time at which the nucleotide excision repair (NER) genes were activated. Thus, apigenin accelerated reversal of UV-B-induced CPDs through up-regulation of NER genes, removal of cyclobutane rings, inhibition of ROS generation, and down-regulation of NF-κB and MAPK, thereby revealing the precise mechanism of DNA repair.
authors.affiliation: Cytogenetics and Molecular Biology Laboratory, Department of Zoology, University of Kalyani, Kalyani, India.
authors.forename: Sreemanti
authors.initials: S
authors.lastname: Das
authors.forename: Jayeeta
authors.initials: J
authors.lastname: Das
authors.forename: Avijit
authors.initials: A
authors.lastname: Paul
authors.forename: Asmita
authors.initials: A
authors.lastname: Samadder
authors.forename: Anisur Rahman
authors.initials: AR
authors.lastname: Khuda-Bukhsh
mesh_terms: D000818:Animals; D047310:Apigenin / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D004260:DNA Repair / Q000187:drug effects*; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects; D032502:Lycopodium / Q000737:chemistry*; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology; D020011:Protective Agents / Q000494:pharmacology*; D011740:Pyrimidine Dimers / Q000378:metabolism; D011897:Random Allocation; D017382:Reactive Oxygen Species / Q000378:metabolism; D012867:Skin / Q000187:drug effects / Q000378:metabolism; D013816:Thermodynamics; D014466:Ultraviolet Rays
chemical_list: D010936:Plant Extracts; D020011:Protective Agents; D011740:Pyrimidine Dimers; D017382:Reactive Oxygen Species; D047310:Apigenin
keywords: DNA damage; apigenin; cyclobutane pyrimidine dimers; reactive oxygen species; ultraviolet B