背景:咳嗽变异性哮喘(CVA)是一种以咳嗽为主要症状的慢性炎症性疾病。苏黄镇咳胶囊(苏黄),一种传统的中成药,临床主要治疗CVA。以前的研究表明,苏黄显著提高了CVA,感染后咳嗽(PIC),痰梗阻和气道重塑。然而,苏黄对卵清蛋白诱导(OVA诱导)CVA代谢异常的影响尚不清楚。
目的:本研究旨在确定与苏黄治疗CVA疗效相关的潜在代谢产物,并确定苏黄如何调节代谢物,和不同的代谢物减少炎症和氧化应激。
方法:大鼠在第1天和第7天腹腔注射1mgOVA/100mg氢氧化铝,两周后雾化吸入1%OVA生理盐水,建立CVA模型。大鼠胃内(i.g.)给予1.4g/kg的苏黄,腹膜内注射不同浓度(87.5和175mg/kg/天)的β-羟基丁酸(β-HB),连续2周。26天后,基于GC-MS的代谢组学方法用于观察代谢变化和搜索差异代谢物。咳嗽的次数,咳嗽潜伏期,酶联免疫吸附测定(ELISA),通过组织学分析和定量聚合酶链反应(Q-PCR)来研究苏黄的作用。然后β-HB对CVA大鼠,蛋白质印迹法检测NLRP3炎性体和GSK3β/AMPK/Nrf2信号通路。
结果:结果表明,苏黄治疗可显著提高血清β-HB水平。有趣的是,暴露于外源性β-HB也对OVA诱导的CVA具有保护作用。β-HB显著减少咳嗽次数和延长咳嗽潜伏期,改善肺损伤,减少各种细胞因子的分泌,并直接抑制NLRP3炎性体。此外,β-HB通过激活GSK3β/AMPK信号轴增加Nrf2的核积累,然后使NF-κB信号通路失活,有效保护OVA诱导的CVA免受氧化应激和炎症。
结论:这项研究的结果表明,β-HB可以减轻炎症和氧化应激,血清中β-HB的产生增加可能是苏黄在CVA治疗中发挥其作用的关键因素。
BACKGROUND: Cough variant asthma (CVA) is a chronic inflammatory disease characterized by cough as the main symptom. Suhuang antitussive capsule (Suhuang), one of traditional Chinese patent medicines, mainly treats CVA clinically. Previous studies have shown that Suhuang significantly improved CVA, post-infectious cough (PIC), sputum obstruction and airway remodeling. However, the effect of Suhuang on ovalbumin-induced (OVA-induced) metabolic abnormalities in CVA is unknown.
OBJECTIVE: This study aimed to identify potential metabolites associated with efficacy of Suhuang in the treatment of CVA, and determined how Suhuang regulates metabolites, and differential metabolites reduce inflammation and oxidative stress.
METHODS: Rats were given 1 mg OVA/100 mg aluminum hydroxide in the 1st and 7th days by intraperitoneal injection and challenged by atomizing inhalation of 1% OVA saline solution after two weeks to establish the CVA model. Rats were intragastrically (i.g.) administrated with Suhuang at 1.4 g/kg and β-hydroxybutyric acid (β-HB) were given with different concentrations (87.5 and 175 mg/kg/day) by intraperitoneal injection for 2 weeks. After 26 days, GC-MS-based metabolomic approach was applied to observe metabolic changes and search differential metabolites. The number of coughs, coughs latencies, enzyme-linked immunosorbent assay (ELISA), histological analysis and quantitative-polymerase chain reaction (Q-PCR) were used to investigate the effects of Suhuang. Then β-HB on CVA rats, NLRP3 inflammasome and GSK3β/AMPK/Nrf2 signalling pathway were detected by western blotting.
RESULTS: The results showed that Suhuang treatment significantly enhanced the serum level of β-HB. Interestingly, exposure to exogenous β-HB was also protective against OVA-induced CVA. β-HB significantly reduced the number of coughs and lengthened coughs latencies, improved lung injury, reduced the secretion of various cytokines, and directly inhibited the NLRP3 inflammasome. In addition, β-HB increased the nuclear accumulation of Nrf2 by activating the GSK3β/AMPK signaling axis, and then inactivating the NF-κB signaling pathway, effectively protecting OVA-induced CVA from oxidative stress and inflammation.
CONCLUSIONS: The results of this study shows that β-HB can reduce inflammation and oxidative stress, the increased production of β-HB in serum might be the crucial factor for Suhuang to exert its effect in the treatment of CVA.