核桃仁水提物对皮肤老化小鼠皮肤胶原纤维的作用

Effects of water extracts of walnut kernel on skin collagenous fiber in skin aging mice

目的探讨核桃仁水提物对皮肤老化小鼠皮肤胶原纤维的影响。方法 48只小鼠采用5%D-半乳糖颈背皮下注射和紫外线照射40d,联合建立皮肤衰老小鼠模型,分为衰老模型组和低、中、高剂量(2.0、4.0、8.0 g/kg)核桃仁水提物治疗组,另取12只小鼠,颈背皮下注射等体积的无菌生理盐水,不进行紫外线照射,作为正常组。连续用药治疗30 d。Masson染色观察皮肤胶原纤维形态变化,生化法检测皮肤中羟脯氨酸(Hyp)含量,免疫组织化学及Western印迹法测皮肤基质金属蛋白酶9(MMP-9)表达。结果与正常组比较,模型组动物皮肤胶原纤维厚度变薄,排列松散,Hyp含量明显减少,而MMP-9表达增强。与模型组比较,核桃仁水提物中、高剂量组均能使动物皮肤胶原纤维厚度增加,排列紧密,同时Hyp含量显著升高,MMP-9阳性细胞率及表达量均明显减少。结论核桃仁水提物对皮肤衰老小鼠皮肤胶原纤维有保护作用,可能与增加胶原含量有关。

Objective To explore the influence of water extracts of Juglans regial kernel （WWE） on collagen fibers of skin aging mice.Methods The mouse model of skin aging was established by nape subcutaneous injection of 5 ％ D-galactose into the skin combined with UV irradiation for 40 days on mice.The mice were divided into normal,model and treatment groups（low,middle and high dose groups with 2.0,4.0,8.0 g/kg WWE）.10 mice were injected with equal volume of normal saline into the nape subcutaneously without UV irradiation as normal control group.Mice stomachs were perfused with water extracts of walnut kernel for 30 days.The pathological change of collagen fibers ware examined through masson staining,the content of hydroxyproline（Hyp） was measured by biochemical method,the expression of matrix metalloproteinases 9（MMP-9） was assessed by immunohistochemistry and western blotting.Results Compared with normal group,the collagen fibers in the model group were thinner and looser,the content of Hyp was statistically decreased,but the expression of MMP-9 was obviously raised.While the collagen fibers in both the middle and high dose of WWE groups were thicker and tighter,the content of Hyp were statistically increased,whereas the expression of MMP-9 were significantly decreased.Conclusions The water extracts of walnut kernel can protect the collagen fiber of skin aging mice,and its mechanism may be related to increasing content of collagen.