Yanghe Pingchuan granules mitigates oxidative stress and inflammation in a bronchial asthma rat model: role of the IKK/IκB/NF-κB signalling pathway

Abstract

Background: Bronchial asthma (BA) is a chronic inflammatory airway disease. Previous research has shown that Yanghe Pingchuan granules (YPG), among the granules formulated by the First Affiliated Hospital of the Anhui University of Chinese Medicine, exerts a precise therapeutic effect on BA. We previously showed that YPG improves airway inflammation in BA rats. Other studies have shown that the inhibitor of kappa-B kinase (IKK)/inhibitor of NF-κB (IκB)/nuclear factor kappa-B (NF-κB) signalling pathway plays a key role in inflammation mediation. Therefore, this study explored whether YPG could intervene in BA through the IKK/IκB/NF-κB signalling pathway.

Methods: Ovalbumin-induced method was used to established BA rat model. After successful modelling, the authors used YPG to intervene the rats in BA rats. Hematoxylin-eosin (HE) staining was used to detect the bronchial pathological changes in BA rats, enzyme-linked immunosorbent assay (ELISA) was used to detect the changes of inflammatory factors (IL-1β and IL-6) and oxidative stress indexes malondialdehyde (MDA), superoxide dismutase (SOD) and nitrogen monoxide (NO), Quantitative real-time polymerase chain reactionCR and western blot were used to detect the expression of IKK/IκB/NF-κB signalling pathway.

Results: In BA model rats, YPG significantly improved the inflammatory response in bronchial tissues, reduced inflammatory factors IL-1β and IL-6, alleviated oxidative stress, reduced MDA and NO, and increased SOD. Quantitative real-time polymerase chain reaction and western blot results showed that YPG could block the IKK/IκB/NF-κB signalling pathway.

Conclusion: These findings showed that YPG had a definite therapeutic effect on BA, which may be related to blocking the IKK/IκB/NF-κB signalling pathway and improving inflammation and oxidative stress.

Keywords: IKK/IκB/NF-κB signalling pathway; Yanghe Pingchuan granules; bronchial asthma; inflammation; oxidative stress.

Figure 1

Effect of Yanghe Pingchuan granules (YPG) on histopathologic changes in lungs of an ovalbumin -induced asthma rat model. HE staining was used to detect the specific performance of lung tissue in each group. Magnification, ×400; scale bars, 50 μm. Normal group (A), model group (B), YPG L group (C), YPG M group (D), YPG H group (E), Aminophylline group (F).

Figure 2

Effect of Yanghe Pingchuan granules (YPG) on bronchial fibrosis in an ovalbumin -induced asthma rat model. Masson staining was used to detect pulmonary fibrosis in each group. Magnification, ×400; scale bars, 50 μm. Normal group (A), model group (B), YPG L group (C), YPG M group (D), YPG H group (E), Aminophylline group (F).

Figure 3

Effect of Yanghe Pingchuan granules (YPG) on pulmonary inflammation in bronchial asthma (BA) rats. ELISA was used to detected the expression of IL-6 and IL-1β in serum of rats in each group. Normal group (N), Model group (M), YPG L group (YPG L), YPG M group (YPG M), YPG H group (YPG H), Aminophylline group (Contrast). n=8. ^## P<0.01 vs normal group (N). **P<0.01 vs model group (M).

Figure 4

Regulation of pulmonary oxidative stress by Yanghe Pingchuan granules (YPG) in bronchial asthma (BA) rats. ELISA was used to detected the expression of NO, MDA and SOD in serum of rats in each group. (A) The level change of NO. (B)The level change of MDA. (C)The level change of SOD. Normal group (N), Model group (M), YPG L group (YPG L), YPG M group (YPG M), YPG H group (YPG H), Aminophylline group (Contrast).n=8. ^## P<0.01 vs normal group (N), **P<0.01 vs model group (M), *P<0.05 vs model group (M).

Figure 5

Yanghe Pingchuan granules (YPG) effect on the IKK/IκB/NF-κB signalling pathway in bronchial asthma (BA) rat model. qRT-PCR was used to detected the mRNA levels of IKK, IκB and NF-κB in BA rats. (A) The level change of IKK, (B)The level change of IκB-α, (C)The level change of NF-κB. Normal group (N), Model group (M), YPG L group (YPG L), YPG M group (YPG M), YPG H group (YPG H), Aminophylline group (Contrast). ^## P<0.01 vs normal group (N), **P<0.01 vs model group (M), *P<0.05 vs model group (M).

Figure 6

Yanghe Pingchuan granules (YPG) effect on IKK/IκB/NF-κB signalling pathway expression in (BA) rat model. WB was used to detected the protein levels of IKK, IκB and NF-κB in BA rats. Normal group (N), Model group (M), YPG L group (YPG L), YPG M group (YPG M), YPG H group (YPG H), Aminophylline group (Contrast). ^## P<0.01 vs normal group (N), **P<0.01 vs model group (M), *P<0.05 vs model group (M).