维生素C对紫外线诱导的光老化大鼠皮肤结构的影响

Effects of vitamin C on UV-induced photoaged skin in rats

目的研究维生素C对光老化大鼠皮肤结构的保护作用,为临床用药和保健提供依据。方法用紫外线辐射背部皮肤的方法建立光老化大鼠模型,每周照射2次,连续4周,UVA累计辐射量为123 J/cm2,UVB累计辐射量为5 J/cm2。造模期间,大鼠每天灌胃给予维生素C溶液50 mg/kg,持续30 d。实验结束后,比较模型组和治疗组照射部位皮肤在大体形态、光镜和透射电镜下的组织结构差异。结果与模型组相比,维生素C组以下方面的皮肤结构损伤程度得到减轻:红疹、溃疡、表皮细胞增生、表皮增厚、真皮血管扩张、炎细胞浸润、成纤维细胞增生、内质网扩张、线粒体肿胀和空泡化、弹力纤维变性和局灶性蓄积、胶原纤维横断面粗细不均。结论大鼠皮肤光老化模型建立成功。维生素C对紫外线诱导的光老化皮肤结构损伤有明显的保护作用。

Objective To study the protective effect of vitamin C on UV-induced photoaged skin structure in rats and provide a basis for clinical medicine and health care. Methods Photoaging skin models were set up by chronic ultraviolet radiation in 24 SPF female Sprague-Dawley rats,irradiated twice weekly for 4 weeks. The rat photoaged skin was induced by exposure to a total dose of 123 J / cm2 UVA and 5 J / cm2 UVB for 4 weeks. Vitamin C was administered by gastric gavage in a dose of 50 mg / kg once daily for 30 days during the model development. We compared the pathological changes in the irradiated skin using HE,Masson’s trichrome and Victoria blue B staining,and compared the ultrastructural changes by electron microscopy. Results Rat models with photoaged skin were developed successfully. The vitamin C group showed significant reduction of pathological severity including erythema, ulcers, epidermal cell proliferation,epidermal thickness,dermis vasodilation,inflammatory cell infiltration,fibroblast proliferation,endoplasmic reticulum dilatation,mitochondrial swelling and vacuolization,elastic fibers degeneration and focal accumulation,collagen fibers swelling with uneven thickness,compared with the rats of model group at the irradiation site. Conclusions Vitamin C is effective in reducing the structural damage of UV-induced photoaged skin in rats.