Scrophularia koraiensis Nakai Attenuates Allergic Airway Inflammation via Suppression of NF-κB and Enhancement of Nrf2/HO-1 Signaling.

Tae-Yang Jung,Je-Oh Lim,Min Young Lee,Je-Won Ko,In-Sik Shin,Na-Rae Shin,A Yeong Lee,Jun-Ho Song,Jong-Choon Kim,Se-Jin Lee,Joong-Sun Kim

doi:10.3390/antiox9020099

Abstract

Scrophularia koraiensis Nakai (Scrophulariaceae) is a medicinal herb that grows in Korea and which has been widely used to treat fever, edema, neuritis and laryngitis. Hence, we evaluated the anti-inflammatory and antioxidant effects of the ethanol extract (SKE) of S. koraiensis Nakai in an ovalbumin (OVA)-induced mouse model. We injected 20 μg of OVA with 2 mg of aluminum on day 0 and day 14 to induce allergic airway inflammation in six-week-old BALB/c mice, and mice were challenged with 1% OVA by nebulization for 1 h on days 21, 22, and 23. SKE was orally administered at 20 mg/kg and 40 mg/kg from day 18 to 23, and its effects were compared with those of montelukast treatment. SKE significantly reduced proinflammatory cytokines, inflammatory cell counts, immunoglobulin-E, and airway hyperresponsiveness during the OVA-induced allergic airway inflammation model; it also reduced airway inflammation and mucus production. In addition, SKE reduced the OVA-induced nuclear factor kappa B (NF-κB) phosphorylation in lung tissues while enhancing nuclear factor erythroid-derived 2-related factor (Nrf-2) and heme oxygenase-1 (HO-1) expression. In conclusion, SKE showed the protective effects on OVA-induced allergic airway inflammation via the suppression of NF-κB phosphorylation and the enhancement of the Nrf2/HO-1 signaling pathway. These results indicate that SKE is a potential therapeutic agent for allergic airway inflammation.

Highlights

Asthma is a chronic inflammatory disease that affects 275 million people worldwide [1]
Asthma characterized the chronic inflammation of the respiratory mucus and airway hyperresponsiveness (AHR), all is of which result inby airway obstruction and the interruption of normalsystem, airflow [20,21]
We investigated the protective effects of S. koraiensis (SKE) in an OVA-induced allergic airway production, and AHR, all of which result in airway obstruction and the interruption of normal airflow

Summary

Introduction

Asthma is a chronic inflammatory disease that affects 275 million people worldwide [1]. It is caused by exposure to specific allergens that aggravate inflammation, mucus hypersecretion, and airway hyperresponsiveness (AHR), resulting in the loss of normal lung function [2,3]. The development of asthma is associated with the increased production of pro-inflammatory cytokines, chemokines, growth factors, and reactive oxygen species (ROS), which. Antioxidants 2020, 9, 99 eventually lead to eosinophilia, AHR, and mucus overproduction [5,6,7]. Oxidative stress is associated with the development of asthma [3]. Oxidative stress occurs because of an imbalance between external oxidation inducers and the antioxidant response within cells, resulting in the production of ROS [11], which induces asthmatic responses via the activation of inflammatory signaling [12,13]. The antioxidant signaling molecules, nuclear factor erythroid-derived

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Conclusion