银耳多糖是银耳中的主要活性物质，具有抗氧化、抗衰老等多种功效。环境中广泛存在的化学污染物苯并[a]芘（Benzo[A]Pyrene，BaP）可通过皮肤吸收代谢，产生致癌性风险。实验通过体外测定银耳粗多糖抗氧化活性，再通过细胞实验测定BaP与银耳多糖共同作用下成纤维细胞中胶原蛋白（Collagen I、Collagen III）、弹性蛋白（Elastin）和间质胶原酶（Matrix Metalloproteinases-1，MMP-1）的mRNA表达量的变化，及Collagen I的蛋白质含量，测定多糖的抗衰老作用。研究发现，银耳多糖有较好的体外抗氧化活性，超氧阴离子自由基清除率最高为70.28%，DPPH自由基清除率为50.10%，羟基自由基清除率为32.69%。仅0.1 μg/mL银耳多糖能有效抑制20 μmol/L BaP对相关基因表达的刺激（P<0.05）。其中Collagen I、Collagen III和Elastin基因表达量呈现多糖浓度依赖性增加。在BaP暴露下，尽管胶原蛋白基因表达量增大至1.26倍，但是大量表达的MMP-1降解了胶原蛋白，因此银耳多糖作用下Collagen-1的含量减少至3.06 μg/L（低于空白对照组3.48 μg/L）。说明银耳多糖能有效抑制化BaP对细胞的伤害，并促进细胞基因的表达，其中浓度具重要影响。

Tremella polysaccharide is the main active substance in Tremella, possessing various functions such as antioxidant and anti-aging effects. The widely occurring chemical contaminant in the environment, benzo[a]pyrene (BaP), can be absorbed through the skin and metabolized, thereby posing a risk of carcinogenicity. In this experiment, the antioxidant activity of crude Tremella polysaccharide was measured in vitro, and then cellular assays were conducted to determine the changes in mRNA expression of collagen (Collagen I, Collagen III), Elastin and matrix metalloproteinases-1 (MMP-1) in fibroblasts under the combined effect of BaP and Tremella polysaccharide, along with the protein content of Collagen I. The anti-aging effect of polysaccharides was also determined. It was found that Tremella polysaccharide had good in vitro antioxidant activity with the highest superoxide anion radical scavenging rate of 70.28%, DPPH scavenging rate of 50.10% and hydroxyl radical scavenging rate of 32.69%. Tremella polysaccharide only at 0.1 μg/mL could effectively inhibit the stimulation of related gene expression by BaP at 20 μmol/L (P<0.05). The expression of Collagen I, Collagen III and Elastin genes increased in a polysaccharide concentration-dependent manner. Under BaP exposure, although collagen gene expression increased to 1.26-fold, the heavily expressed MMP-1 caused the degradation of collagen, therefore, under the effect of Tremella polysaccharide, the content of Collagen-1 decreased to 3.06 μg/L (which was lower than the value of the blank control: 3.48 μg/L). The results indicated that Tremella polysaccharide could effectively inhibit the BaP-induced damage to cells and promote the expression of cell genes (on which the concentration had an important influence).

广东省科技计划项目（KTP20210091；KTP20210191；2020B121202014）；湛江市科技计划项目（2022A01210）