毛蕊花糖苷防晒霜对紫外线辐射诱导大鼠皮肤损伤的保护作用研究

Protective effect of verbascoside sunscreen cream against ultraviolet irradiation induced photodamage to skin damage in rats

目的建立UVB辐射诱导大鼠皮肤损伤模型,探讨毛蕊花糖苷防晒霜抗紫外线辐射的作用及机制。方法选取背部皮肤恢复成光滑、无损伤的大鼠建立紫外损伤模型。照射条件为紫外线(320 nm)照射,照射强度为1.8 J·cm^(-2),每日照射3 min,连续3 d。49只大鼠随机分为空白组(无紫外线照射)、模型组(紫外线照射)、基质组(紫外线照射+空白基质),高剂量组(紫外线照射+6%毛蕊花糖苷防晒霜)、中剂量组(紫外线照射+4%毛蕊花糖苷防晒霜)、低剂量组(紫外线照射+2%毛蕊花糖苷防晒霜)及阳性对照组(市售防晒霜)。大鼠照射期间,每日观察背部皮肤损伤情况。末次背部照射后,取照射区皮肤组织进行苏木精-伊红染色和天狼猩红染色观察皮肤组织形态及胶原纤维的变化,Tunel染色检测细胞凋亡情况,检测皮肤抗氧化能力[超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、谷胱甘肽硫转移酶(GST)、过氧化氢(H_(2)O_(2))、羟脯氨酸(Hyp)],免疫组化检测cleaved caspase-3的变化。结果大鼠背部紫外照射后,皮肤呈现粗糙增厚、红肿溃烂等不同程度的损伤,胶原纤维变性紊乱。与模型组比较,毛蕊花糖苷不同剂量组皮肤损伤程度明显减轻,皮肤组织SOD活性、GSH含量和GST活力均升高,而H_(2)O_(2)、Hyp含量下降(P<0.05或P<0.01),其中毛蕊花糖苷高剂量组效果最好。同时,凋亡细胞及cleaved caspase-3的阳性细胞率减少,显示毛蕊花糖苷防晒霜处理后可减轻细胞凋亡。结论毛蕊花糖苷防晒霜可提高皮肤抗氧化应激活性,降低氧化产物含量,抑制细胞凋亡,达到抗紫外线辐射损伤作用。

Objective To establish a rat skin damage model by ultraviolet irradiation,and determine the anti-ultraviolet radiation mechanism of verbascoside sunscreen cream.Methods Rats with smooth and undamaged back skin were selected to establish the ultraviolet irradiation damage model.The irradiation conditions inclued ultraviolet irradiation at 320 nm,irradiation intensity at 1.8 J·cm^(-2),and irradiation for 3 min for three consecutive days.Totally 49 Wistar rats were randomly divided into 7 groups:a blank group(no irradiation),a model group(ultraviolet irradiation),a matrix group(ultraviolet irradiation+blank substrate),a high dose group(ultraviolet irradiation+6%verbascoside sunscreen cream),a medium dose group(ultraviolet irradiation+4%verbascoside sunscreen cream),a low-dose group(ultraviolet irradiation+2%verbascoside sunscreen cream)and a control group(commercially available sunscreen cream).During the irradiation,pictures were taken every day to observe the skin damage on the rat back.After the last irradiation,skin tissues were taken from the irradiated area for hematoxylin-eosin staining and sirius red staining to observe the skin tissue morphology and the changes in the collagen fibers.Tunel staining detected cell apoptosis.Oxidative stress of the skin was detected[superoxide dismutase(SOD),glutathione(GSH),glutathione S-transferase(GST),hydrogen peroxideH_(2)O_(2),and hydroxyproline(Hyp)];cleaved caspase-3 change was detected by immunohistochemical technique.Results After the irradiation,the skin became rough and thickened,red and swollen,fester with different degrees.The collagen fibers were degenerated and disordered.Compared with the model group,the degree of skin damage in different doses of verbascoside was significantly reduced,SOD activity,GSH content and GST activity in the skin tissues were increased,while the content of H_(2)O_(2) and Hyp decreased(P<0.05 or P<0.01),with better effect in the high-dose group.At the same time,the decrease of apoptotic cells and cleaved caspase-3 positive cells indicated that verbascoside sunscreen cream alleviated the cell apoptosis.Conclusion Verbascoside sunscreen cream can improve the anti-oxidative stress activity of the skin,reduce the oxidative products,and inhibit the cell apoptosis,thus the effect of anti-ultraviolet irradiation damage.