基于皮肤外燥模型小鼠的干燥皮肤综合评价及银耳多糖的干预研究

目的 制备皮肤外燥模型小鼠，对小鼠皮肤进行综合评价并研究银耳多糖内服、外用的干预作用。方法 10只KM小鼠置于人工气候箱内按“温度-湿度-风”综合条件建立皮肤外燥小鼠模型；另90只KM小鼠，除空白组常规饲养，其余各组按外燥造模条件饲养。银耳多糖的干预研究分为内服和外用，内服给药动物随机分为空白组、模型组（等量生理盐水）和银耳多糖组（400，200，100 mg·kg^-1）；外用给药动物分为经皮空白组、经皮模型组（等量生理盐水）、经皮银耳多糖组（银耳多糖10 mg·cm^-2）和阳性对照组[透明质酸（hyaluronic acid，HA）10 mg·cm^-2]，每日1次，连续给药20 d。观测不同给药方式在银耳多糖干预下小鼠皮肤表观特征、含水量、组织结构、HA含量以及水通道蛋白3（aquaporin-3，AQP3）表达量的影响。结果 皮肤综合评价结果表明，外燥模型建立成功；在银耳多糖干预下，与空白组比较，内服与外用给药的模型组皮肤含水量、HA含量以及AQP3表达量降低（P<0.05）；与模型组相比，各给药组可显著提高皮肤含水量、HA含量以及AQP3表达量（P<0.05），且内服以银耳多糖高剂量组效果最好（P<0.05），外用经皮银耳多糖组效果优于阳性对照组（P<0.05）。各给药组较模型组皮肤恢复色泽，未见明显皮屑与裂纹，毛发可正常增长，皮肤组织结构相对完整，毛囊与皮脂腺数目增多。结论 外燥可致皮肤干燥的理论成立。银耳多糖对皮肤外燥模型小鼠内服外用具有延缓干燥的功效，其作用可能与银耳多糖调节皮肤HA和AQP3表达量相关。

Comprehensive Evaluation of Dry Skin and Intervention of Tremella Polysaccharides Based on the Model Mice with Outer-dry Skin

OBJECTIVE To evaluate the skin of mice comprehensively and study the effect of intervention with tremella polysaccharides by establishing mice model with outer-dry skin. METHODS Ten KM mice were placed in an artificial climate chamber to establish the model mice with outer-dry skin according to the "temperature-humidity-wind" comprehensive conditions; while other 90 KM mice, except the blank group, were kept under the conditions of external dryness. The intervention study of tremella polysaccharides was divided into oral and topical administration, mice of oral administration were randomly divided into blank control group and model control group (equal saline), tremella polysaccharide groups (400, 200, 100 mg·kg^-1 tremella polysaccharide); mice of topical administration were randomly divided into percutaneous blank group and model group (equal physiological saline), tremella polysaccharide group (tremella polysaccharide 10 mg·cm^-2) and positive control group (HA 10 mg·cm^-2), each group was treated by different ways of administration once a day for 20 days. The surface characteristics, water content, tissue structure, HA and AQP3 expression of mice were counted as obervation indicators of the skin situation under the intervention of Tremella polysaccharides with different administration methods. RESULTS After comprehensive evaluation of skin, the model was established successfully. Under the intervention of Tremella polysaccharides, compared with the blank group, the skin water content, HA and AQP3 content of the model group with oral and topical administration was decreased (P<0.05). Compared with the model group, the water content, HA content and AQP3 expression were significantly increased in each drug group (P<0.05), and the effect of 400 mg·kg^-1 tremella polysaccharide group was the best among oral groups and the topical tremella polysaccharide group was better than that of the positive control group among the external administration groups (P<0.05). Compared with the model group, the skin of each drug group, without obvious dandruff and crack, became sleeker and glossier; the hair of mice grew normally, the skin structure was intact, and the number of hair follicles and sebaceous glands increase. CONCLUSION Based on the theory of external dryness resulting in skin dryness, tremella polysaccharides can alleviate dryness of skin effectively that may related to the regulation of HA and AQP3 in the skin