Medical School, Huanghe Science & Technology University, Zhengzhou 450063, PR China; College of Medicine, Zhengzhou University, Zhengzhou 450001, PR China; Henan Joint International Research Laboratory of Drug Discovery of Small Molecules, Huanghe Science & Technology University, Zhengzhou 450063, PR China.
Medical School, Huanghe Science & Technology University, Zhengzhou 450063, PR China.
J Photochem Photobiol B. 2019 Feb;191:135-142. doi: 10.1016/j.jphotobiol.2018.12.001. Epub 2018 Dec 5.
Natured botanical extract has attracted considerable attention recently in the field of skin anti-ultraviolet (UV) radiation. As a medicinal herb, Sophora japonica flower buds contained several components such as flavonoids, isoflavonoids, triterpenes, alkaloids and polysaccharides, which have multiple pharmacological properties except hemostatic agents which have been used in China and Korea for centuries. The purpose of our study was to investigate whether polysaccharide extracted from Sophora japonica L. flower buds (PS) was able to attenuate UVB-induced damage using a human keratinocyte cell line (HaCaT cells). HaCaT cells were pretreated with PS in a serum-free medium for 2 h and then irradiated with different doses of UVB rays. The results showed that the PS attenuated UVB-induced cytotoxicity which was verified by MTT method and morphology feature assay. UVB exposure (30-120 mJ/cm) reduced HaCaT cells viability significantly following with the increased irradiation dose 24 h later, while pretreatment with PS (0.25-2.0 mg/mL) attenuated UVB-induced cytotoxicity significantly and increased cell viability in a dose-dependent manner except 30 mJ/cm group. The PS reduced the ROS generation, down-regulated the expression of phosphor-JNK and phosphor-p38 MAPK proteins significantly through MAPK pathway in UVB-irradiated HaCaT cells. It also decreased the apoptosis rate at low dose of UVB ray and protected the cells from apoptosis which had been identified by the down-regulated level of active-caspase3 in UVB-irradiated HaCaT cells. In conclusion, PS pretreatment protected HaCaT keratinocytes from UVB irradiation-induced skin injuries effectively, and the underlying mechanism may involve MAPK signaling pathway which contribute to apoptotic cell death. However, further studies especially whose using human systems are needed to determine efficacy of PS in vivo.
天然植物提取物在皮肤抗紫外线（UV）辐射领域引起了相当大的关注。作为一种药用草本植物，槐花蕾中含有多种成分，如黄酮类、异黄酮类、三萜类、生物碱和多糖等，除了在中国和韩国使用了几个世纪的止血剂外，还具有多种药理作用。我们的研究目的是探讨槐花蕾中提取的多糖（PS）是否能够通过人角质形成细胞系（HaCaT 细胞）减轻 UVB 诱导的损伤。HaCaT 细胞在无血清培养基中用 PS 预处理 2 小时，然后用不同剂量的 UVB 射线照射。结果表明，PS 通过 MTT 法和形态特征检测减轻了 UVB 诱导的细胞毒性。UVB 暴露（30-120 mJ/cm）在 24 小时后随着照射剂量的增加显著降低了 HaCaT 细胞的活力，而 PS（0.25-2.0 mg/mL）预处理显著减轻了 UVB 诱导的细胞毒性，并呈剂量依赖性增加了细胞活力，除了 30 mJ/cm 组。PS 通过 MAPK 途径降低了 ROS 的产生，显著下调了 UVB 照射的 HaCaT 细胞中磷酸化-JNK 和磷酸化-p38 MAPK 蛋白的表达。它还降低了低剂量 UVB 射线诱导的细胞凋亡率，并通过降低 UVB 照射的 HaCaT 细胞中活性 caspase3 的水平来保护细胞免于凋亡。总之，PS 预处理有效保护 HaCaT 角质形成细胞免受 UVB 照射引起的皮肤损伤，其潜在机制可能涉及 MAPK 信号通路，有助于细胞凋亡死亡。然而，需要进一步的研究，特别是使用人体系统的研究，以确定 PS 在体内的疗效。
