Abstract：
Phenylarsine oxide (PAO) is a known environmental pollutant and skin keratinocytes are most seriously affected. Baicalin (BCN) was reported to have antioxidant and anti-inflammatory effects, but its protective effect against PAO toxicity is unknown. This study aimed at exploring whether baicalin can reverse the toxicity of human epidermal keratinocytes that are subjected to PAO exposure and underlying mechanisms. In silico analysis from a publicly accessible HaCaT cell transcriptome dataset exposed to chronic Arsenic showed significant differential expression of several genes, including the genes related to DNA replication. Later, we performed in vitro experiments, in which HaCaT cells were exposed to PAO (500 nM) in the existence of BCN (10-50 µM). Treatment of PAO alone induces the JNK, p38 and caspase-3 activation, which were engaged in the apoptosis induction, while the activity of AKT was significantly inhibited, which was engaged in the suppression of apoptosis. PAO suppressed SIRT3 expression and induced intracellular reactive oxygen species (ROS), causing a marked reduce in cell viability and apoptosis. However, BCN treatment restored the PAO-induced suppression of SIRT3 and AKT expression, reduced intracellular ROS generation, and markedly suppressed both caspase-3 activation and apoptosis induction. However, the protective effect of BCN was significantly attenuated after pretreatment with nicotinamide, an inhibitor of SIRT3. These findings indicate that BCN protects against cell death induced by PAO via inhibiting excessive intracellular ROS generation via restoring SIRT3 activity and reactivating downstream AKT pathway. In this study, we firstly shown that BCN is an efficient drug to prevent PAO-induced skin cytotoxicity, and these findings need to be confirmed by in vivo and clinical investigations.
摘要：
氧化苯胺(PAO)是已知的环境污染物,皮肤角质形成细胞受到最严重的影响。据报道，黄芩苷（BCN）具有抗氧化和抗炎作用，但其对PAO毒性的保护作用尚不清楚。这项研究旨在探索黄芩苷是否可以逆转人表皮角质形成细胞受到PAO暴露的毒性和潜在机制。暴露于慢性砷的公开HaCaT细胞转录组数据集的计算机模拟分析显示了几个基因的显著差异表达，包括与DNA复制相关的基因。稍后，我们进行了体外实验，其中HaCaT细胞在BCN（10-50μM）存在下暴露于PAO（500nM）。单独治疗PAO诱导JNK，p38和caspase-3激活，参与细胞凋亡诱导，而AKT的活性被显著抑制,参与抑制细胞凋亡。PAO抑制SIRT3表达并诱导细胞内活性氧（ROS），导致细胞活力和细胞凋亡的显著降低。然而,BCN处理恢复了PAO诱导的SIRT3和AKT表达的抑制，减少细胞内ROS的产生，并显着抑制caspase-3的激活和凋亡诱导。然而,烟酰胺预处理后BCN的保护作用显着减弱，SIRT3的抑制剂。这些发现表明，BCN通过恢复SIRT3活性并重新激活下游AKT途径来抑制过度的细胞内ROS产生，从而防止PAO诱导的细胞死亡。在这项研究中,我们首先证明了BCN是一种有效的预防PAO引起的皮肤细胞毒性的药物,这些发现需要通过体内和临床研究来证实。
