The Role and Mechanisms of Traditional Chinese Medicine for Airway Inflammation and Remodeling in Asthma: Overview and Progress

Abstract

Asthma as an individual disease has blighted human health for thousands of years and is still a vital global health challenge at present. Though getting much progress in the utilization of antibiotics, mucolytics, and especially the combination of inhaled corticosteroids (ICS) and long-acting β-agonists (LABA), we are confused about the management of asthmatic airway inflammation and remodeling, which directly threatens the quality of life for chronic patients. The blind addition of ICS will not benefit the remission of cough, wheeze, or sputum, but to increase the risk of side effects. Thus, it is necessary to explore an effective therapy to modulate asthmatic inflammation and airway remodeling. Traditional Chinese Medicine (TCM) has justified its anti-asthma effect in clinical practice but its underlying mechanism and specific role in asthma are still unknown. Some animal studies demonstrated that the classic formula, direct exacts, and natural compounds isolated from TCM could significantly alleviate airway structural alterations and exhibit the anti-inflammatory effects. By investigating these findings and data, we will discuss the possible pathomechanism underlined airway inflammation and remodeling in asthma and the unique role of TCM in the treatment of asthma through regulating different signaling pathways.

Keywords: TCM; airway inflammation; airway remodeling; asthma; autophagy.

FIGURE 1

Schematic overview of major mechanisms and related signaling pathways in asthmatic inflammation and airway remodeling (ECM: extracellular matrix; TGF-β: transforming growth factor-beta; VEGF: vascular endothelial growth factor; TLR4: Toll-like receptor 4; Nrf2: nuclear factor erythroid-2 related factor 2; RhoA: ras homolog family member A; ROCK: rho-associated coiled-coil containing protein kinase; LIMK: LIM domain kinase; MAPK: mitogen-activated protein kinase; PI3K: phosphatidylinositol-4,5-bisphosphate 3-kinase; Akt: AKT serine/threonine kinase; mTOR: mechanistic target of rapamycin kinase; NF-κB: nuclear factor kappa B; HO-1: hemeoxygenase-1; ROS: reactive oxygen species; APC: antigen presenting cell; MMP: matrix metallopeptidase; IL: interleukin; IgE: immunoglobulin E).

FIGURE 2

The major targets and mechanisms of TCM involved in anti-airway inflammation and remodeling. Black star indicates Gu-Ben-Fang-Xiao decoction, Jia-Wei-Yu-Ping-Feng-San, ginsenoside Rg1/3, ligustrazine, bulleyaconitine A, andrographolide, and osthole; the gray one represents Xiaochuanping powder, glycyrrhizic acid, and curcumin; brown star signifies curcumol; purple star means Yanghe Pingchuan granules, Soufeng Yuchuan decoction, Pingchunning Decoction, luteolin, and emodin; red star refers to Mahuang Decoction, Jin-Gui-Shen-Qi Wan, piperlongumine, evodiamine, baicalin, curcumin, chrysophanol, shikonin, and resveratrol; orange star denotes Bu-Shen-Yi-Qi fangm cordycepin, and icariin; blue star implies Mahuang Decoction, Fangxiao formula, and sinomenine; green star suggests tetrandrine, polydatin, and imperatorin.