枸杞多糖抗长波紫外线致大鼠皮肤损伤的保护作用研究

Study on the Protective Effect of Lycium barbarum Polysaccharides on Rat Skin from Longwave Ultraviolet Injury

摘要: 目的：建立长波紫外线(UVA)诱导的皮肤光老化大鼠模型并研究枸杞多糖是否可以抵御长波紫外线所致的皮肤光老化损伤。方法：将40只大鼠随机分为4组，设立对照组、仅接受UVA照射组、UVA + 枸杞多糖组和UVA + 甘油组。采取连续一周每日照射半小时UVA (强度为0.0265 J·cm^-2·s^-1)的方法，建立皮肤光老化的实验动物模型。每日照射UVA之前，在UVA + 枸杞多糖组UVA照射区域的皮肤上涂抹枸杞多糖甘油混悬剂。在UVA + 甘油组照射处皮肤涂抹甘油。观察照射部位皮肤的HE染色切片、胶原纤维的Masson染色切片和Cleaved Caspase-3免疫组化染色切片。结果：与对照组相比，UVA组和UVA + 甘油组角质形成细胞大量增生，无极性排列，皮肤增厚明显(P < 0.01)。皮脂腺大量增生呈聚集状，炎症细胞浸润明显，Masson染色示胶原纤维含量减少。免疫组化Cleaved Caspase-3表达量与对照组相比明显上升，差异具有统计学意义(P < 0.01)。UVA + 枸杞多糖组与UVA组相比照射区皮肤增厚减少(P < 0.01)，黑色素颗粒减少，皮脂腺增生减轻，细胞坏死减少，炎细胞浸润减轻，Masson染色提示胶原纤维含量上升，凋亡因子Cleaved Caspase-3表达下降(P < 0.01)。结论：该强度长波紫外线连续照射一周可以成功构建皮肤光老化的模型。枸杞多糖对长波紫外线损伤有保护作用。

Abstract: Objective: To establish a rat model of skin photoaging induced by long-wave ultraviolet (UVA) and investigate whether Lycium barbarum polysaccharide can resist the skin photoaging damage caused by long-wave ultraviolet. Methods: Forty rats were randomly divided into 4 groups, a control group, a UVA irradiation group only, a UVA + Lycium barbarum polysaccharide group and a UVA + glycerol group. An experimental animal model of skin photoaging was established by irradiating UVA for half an hour (intensity of 0.0265 J·cm^-2·s^-1) every day for one week. Before daily UVA irradiation, apply Lycium barbarum polysaccharide glycerol suspension on the skin of UVA-irradiated area in UVA + Lycium barbarum polysaccharide group. Apply glycerin to the skin in the UVA + glycerin group irradiated. The HE-stained sections of the irradiated skin, Masson-stained sections of collagen fibers and Cleaved Caspase-3 immunohistochemically stained sections were observed. Results: Compared with the control group, the keratinocytes in the UVA group and UVA + glycerol group proliferated massively, with no polarity arrangement, the skin thickened significantly (P < 0.01). Massive hyperplasia of sebaceous glands in the shape of a cluster, massive infiltration of inflammatory cells, and Masson staining showed that the content of collagen fibers decreased. Compared with the control group, the expression of Cleaved Caspase-3 by immunohistochemistry was significantly increased, and the difference was statistically significant (P < 0.01). Compared with the UVA group, the UVA + Lycium barbarum polysaccharide group had less skin thickening in the irradiated area (P < 0.01), fewer melanin granules, less sebaceous gland hyperplasia, less collagen breakage, less cell necrosis, less inflammatory cell infiltration, and Masson staining indicated that the content of collagen fibers increased. The expression of apoptosis factor Cleaved Caspase-3 decreased (P < 0.01). Conclusion: Continuous irradiation of long-wave ultraviolet rays with this intensity for one week can successfully build a model of skin photoaging. Lycium barbarum polysaccharide has a protective effect on long-wave ultraviolet damage.