Protective effect of the isoflavone equol against DNA damage induced by ultraviolet radiation to hairless mouse skin. 2006

Sitarina Widyarini
Department of Veterinary Pathology, Faculty of Veterinary Medicine, Gadjah Mada University, Jl. Olah Raga, Karang Malang, Yogyakarta, Indonesia. sitarina_id@yahoo.com.au

Equol, an isoflavonoid metabolite produced from the dietary isoflavone daidzein by the gut microflora in mammals, has been found to protect not only against ultraviolet (UV) radiation-induced cutaneous inflammation and photoimmune suppression, but also have antiphotocarcinogenic properties in mice. Because the state of DNA damage has been correlated with suppression of the immune system and photocarcinogenesis, we have therefore examined the potential of equol to offer protection from solar-simulated UV (SSUV) radiation-induced DNA damage in hairless mice by the immunohistochemical approach using monoclonal antibody specific for cyclobutane pyrimidine dimers (CPDs; H3 antibody). Topical application of 20 microM equol lotion, which was applied both before and after SSUV significantly reduced the number of CPDs. This reduction was evident immediately after SSUV exposure, at 1 h after exposure, and at 24 h after exposure, revealing 54%, 50%, and 26% reduction in CPDs, respectively. When the same concentration was applied for 5 consecutive days after SSUV exposure, there was no significant difference in the reduction of CPDs immediately after SSUV irradiation or at 1 hour afterwards, but there were significant reductions of 23% and 42% at 24 and 48 h after SSUV exposure, respectively. Despite apparently reducing the number of CPDs post-SSUV, topically applied equol did not appear to increase the rate of dimer removal. To conclude, equol applied topically prior to SSUV irradiation offers protection against CPD formation in hairless mice, possibly by acting as a suncreen and thus inhibiting DNA photodamage.

UI MeSH Term Description Entries
D007150 Immunohistochemistry Histochemical localization of immunoreactive substances using labeled antibodies as reagents. Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D007529 Isoflavones 3-Phenylchromones. Isomeric form of FLAVONOIDS in which the benzene group is attached to the 3 position of the benzopyran ring instead of the 2 position. 3-Benzylchroman-4-One,3-Benzylidene-4-Chromanone,Homoisoflavone,Homoisoflavones,Isoflavone,Isoflavone Derivative,3-Benzylchroman-4-Ones,3-Benzylidene-4-Chromanones,Isoflavone Derivatives,3 Benzylchroman 4 One,3 Benzylchroman 4 Ones,3 Benzylidene 4 Chromanone,3 Benzylidene 4 Chromanones,Derivative, Isoflavone,Derivatives, Isoflavone
D008812 Mice, Hairless Mutant strains of mice that produce little or no hair. Hairless Mice,Mice, Inbred HRS,Mice, hr,Hairless Mouse,Mice, HRS,Mouse, HRS,Mouse, Inbred HRS,HRS Mice,HRS Mice, Inbred,HRS Mouse,HRS Mouse, Inbred,Inbred HRS Mice,Inbred HRS Mouse,Mouse, Hairless
D011740 Pyrimidine Dimers Dimers found in DNA chains damaged by ULTRAVIOLET RAYS. They consist of two adjacent PYRIMIDINE NUCLEOTIDES, usually THYMINE nucleotides, in which the pyrimidine residues are covalently joined by a cyclobutane ring. These dimers block DNA REPLICATION. Cyclobutane Pyrimidine Dimer,Cyclobutane-Pyrimidine Dimer,Cytosine-Thymine Dimer,Pyrimidine Dimer,Thymine Dimer,Thymine Dimers,Cyclobutane-Pyrimidine Dimers,Cytosine-Thymine Dimers,Thymine-Cyclobutane Dimer,Thymine-Thymine Cyclobutane Dimer,Cyclobutane Dimer, Thymine-Thymine,Cyclobutane Dimers, Thymine-Thymine,Cyclobutane Pyrimidine Dimers,Cytosine Thymine Dimer,Cytosine Thymine Dimers,Pyrimidine Dimer, Cyclobutane,Pyrimidine Dimers, Cyclobutane,Thymine Cyclobutane Dimer,Thymine Thymine Cyclobutane Dimer,Thymine-Cyclobutane Dimers,Thymine-Thymine Cyclobutane Dimers
D004247 DNA A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine). DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004249 DNA Damage Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS. DNA Injury,DNA Lesion,DNA Lesions,Genotoxic Stress,Stress, Genotoxic,Injury, DNA,DNA Injuries
D005260 Female Females
D000287 Administration, Topical The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example. Drug Administration, Topical,Administration, Topical Drug,Topical Administration,Topical Drug Administration,Administrations, Topical,Administrations, Topical Drug,Drug Administrations, Topical,Topical Administrations,Topical Drug Administrations
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D012867 Skin The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.

Related Publications

Sitarina Widyarini
August 2008, Photodermatology, photoimmunology & photomedicine,
Copied contents to your clipboard!