Protective effect of the Baicalin against DNA damage induced by ultraviolet B irradiation to mouse epidermis.
OBJECTIVE
To investigate whether topical application of Baicalin affords protecting Balb/C mice epidermis from ultraviolet (UV)B-induced DNA damage and its underlying mechanisms.


METHODS
A DNA damage model of UVB irradiation-induced mice epidermis was established. The immunohistochemical staining, Southwestern dot-blotting were used for cyclobutane pyrimidine dimers (CPDs) detection; Western blotting was used for p53 detection; reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA level of Bcl-2 and Bax; terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) was used to detect apoptotic cells.


RESULTS
Topical application of Baicalin on Balb/C mice skin significantly decreased the amount of epidermal CPDs 1, 24 and 48 h after 180 mJ/cm(2) of UVB irradiation as compared with untreated mice. UVB-induced apoptosis was less pronounced in Baicalin-treated mice epidermis, which was accompanied by less p53 accumulation and higher Bcl-2/Bax ratio compared with that of untreated mice.


CONCLUSIONS
Taken together, these results suggest that topical Baicalin application mitigates DNA photo-damage. Baicalin is therefore a promising protective substance against UVB radiation.
Bing-Rong
Zhou
Z
Department of Dermatology, First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
Song-Liang
Jin
J
Xiao-E
Chen
C
Xiang-Fei
Lin
L
Bao-Xiang
Cai
C
Jie
Gao
G
Dan
Luo
L
D000279:Administration, Cutaneous; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D004247:DNA / Q000032:analysis; D004249:DNA Damage / Q000187:drug effects*; D004817:Epidermis / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology / Q000528:radiation effects*; D005260:Female; D005419:Flavonoids / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010936:Plant Extracts / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D011740:Pyrimidine Dimers / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D031364:Scutellaria baicalensis; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects*; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
C494827:Bax protein, mouse; D005419:Flavonoids; D010936:Plant Extracts; D019253:Proto-Oncogene Proteins c-bcl-2; D011740:Pyrimidine Dimers; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein; C038044:baicalin; D004247:DNA