熊果苷对黄褐斑鼠模型治疗效果及机制研究

目的 复制黄褐斑鼠模型，予熊果苷干预，观察其疗效并探讨可能机制。方法 将50 只SPF 级雌性 豚鼠按体重随机分为空白组、模型组以及熊果苷低、中、高剂量治疗组，每组10 只。除空白组外，其他组采用 肌内注射黄体酮法复制黄褐斑鼠模型，并在其皮肤局部分别外涂熊果苷软膏与氢醌霜，连续治疗30 d。末次给 药1 天后处死豚鼠并迅速提取涂药部位皮肤，测定酪氨酸、丙二醛（MDA）含量及超氧化物歧化酶（SOD）活 性，并对皮肤组织进行HE 染色以观察病理形态学变化。结果 所有熊果苷治疗组用药处皮肤中酪氨酸、MDA 含量降低，SOD 活性升高，且以中剂量组最为突出；所有熊果苷治疗组用药处皮肤黑色素沉着面积缩小、着色 变浅，尤以中剂量组最为突出。结论 熊果苷对黄褐斑模型鼠有较好的治疗作用，其机制可能与提高皮肤局部组 织中SOD 酶活性，降低酪氨酸、MDA 的含量相关。

Research of effect of arbutin on chloasma in guinea pigs and mechanism

Objective To evaluate the effect the of arbutin on chloasma in guinea pig model and explore the possible mechanism. Methods Fifty female guinea pigs of SPF grade were randomized into five groups by weight including a blank group, a model group, a low-dose arbutin group, a middle-dose arbutin group, and a high-dose arbutin group with 10 in each group. Except for the blank group, intramuscular injection of progesterone was adopted in all of the guinea pigs to induce chloasma model. The guinea pigs were killed after treated with different doses of arbutin ointment and hydroquinone cream for 30 d. A piece of skin from the lesion was collected for the detection of tyrosine content, SOD activity and MDA content; another piece of the lesion was collected for pathological observation after HE staining and for immunohistochemical detection. Results SOD activity obviously increased, MDA and tyrosine content reduced in the skin of chloasma in all the arbutin groups, which were more obvious in the medium-dose arbutin group. In all the arbutin groups the area of melanin in the skin of chloasma reduced and the color became lighter, especially in the medium-dose arbutin group. Conclusions Arbutin has a good effect on experimental chloasma guinea pig model, probably through increasing SOD activity and reducing MDA and tyrosine content.