构树总黄酮对长波紫外线引起人角质形成细胞损伤的防护作用

Protective effects of total flavonoids of broussonetia papyrifera on oxidative injury of ultraviolet A to human keratinocytes

目的研究长波紫外线(UVA)照射对人角质形成细胞的氧化损伤以及构树总黄酮(totalflavonoids of broussonetia papyrifera,TFBP)的防护效果.方法在人角质形成细胞培养的基础上,实验组在照射前加入不同剂量的TFBP,然后和处理组一起接受UVA照射,通过噻唑蓝(MTT)染色法检测细胞活性、裂解液中丙二醛(MDA)含量和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活力,对构树叶提取物的抗氧化效果进行评价.结果随着UVA剂量的增高(0.46～2.76J/cm2),细胞的活性逐渐降低(96.3%～37.5%),添加TFBP 10～200mg/L后,细胞活性升高,MDA含量由(5.14±0.58)mnol/mg pro降低到(2,98±0.14)nmol/mg pro,SOD活力由(23.09±3.91)U/mg pro增加到(34.50±1.59)U/mg pro,GSH-Px活力也有所升高.结论本试验条件下,UVA对人角质形成细胞有明显的氧化损伤,TFBP对这种氧化损伤有防护作用.

Objective To investigate the oxidative damage of ultraviolet A（UVA） to human immotalized keratinocytes line HaCaT and the protective effects of total flavonoids of Broussonetia papyrifera（TFBP） gotten from the leaves of broussoneria 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 MTr reduction assay. Human immotalized 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 theincrease 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） mnol/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. Conclusion Ultraviolet A causes significant oxidative injury to HaCaT cells under the conditions of this study.TFBP gotten from the leaves of broussoneria papyrifera has certain protective effect on HaCaT epithelial cells.