[Protective effects of total flavonoids of Broussonetia papyrifera on oxidative injury of ultraviolet A to human keratinocytes].
OBJECTIVE
To investigate the oxidative damage of ultraviolet A (UVA) to human immortalized keratinocytes line HaCaT and the protective effects of total flavonoids of Broussonetia papyrifera (TFBP) gotten from the leaves of broussonetia papyifera.


METHODS
Based on the culture of the human keratinocytes, the experiment group added with different dosages of TFBP before exposure to the radiation, received the UVA radiation together with the treatment group. The levels of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined in cultured HaCaT cells as well as the cell activity with MTT reduction assay. Human immortalized keratinocytes HaCaT cells received ultraviolet A with the different dosages between 0.46 and 2.76 J/cm(2) respectively. The protective effects of TFBP at different concentrations were also evaluated.


RESULTS
The cell activity decreased gradually from 96.3% to 37.5% with the increase of UVA dosage from 0.46 J/cm(2) to 2.76 J/cm(2). After 10 mg/L up to 200 mg/L of TFBP were added the cell activity increased, the levels of MDA decreased from (5.14 +/- 0.58) nmol/mg pro to (2.98 +/- 0.14) nmol/mg pro, the levels of SOD increased from (23.09 +/- 3.91) U/mg pro to (34.50 +/- 1.59) U/mg pro and the activity of GSH-Px increased somewhat.


CONCLUSIONS
Ultraviolet A causes significant oxidative injury to HaCaT cells under the conditions of this study. TFBP gotten from the leaves of broussonetia papyrifera has certain protective effect on HaCaT epithelial cells.
Wang
Ting
T
Tianjin Centers for Diseases Prevention and Control, Tianjin 300011, China.
Yang
Xue-ying
XY
He
Rui
R
Cao
Yu-guang
YG
D000975:Antioxidants / Q000494:pharmacology*; D031623:Broussonetia / Q000737:chemistry*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D005419:Flavonoids / Q000494:pharmacology*; D005979:Glutathione Peroxidase / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000528:radiation effects; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000528:radiation effects; D008315:Malondialdehyde / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D013482:Superoxide Dismutase / Q000378:metabolism; D014466:Ultraviolet Rays / Q000009:adverse effects*
D000975:Antioxidants; D005419:Flavonoids; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase