Berberine improves airway inflammation and inhibits NF-κB signaling pathway in an ovalbumin-induced rat model of asthma

Berberine has been reported for its various activities including anti-inflammatory effects and has been used in treating many diseases. However, its effects on airway inflammation in asthma have not been investigated. This study mainly aimed to detect its effects on the airway inflammation and the nuclear factor-κB (NF-κB) signaling pathway activity in a rat model of asthma.Asthma was induced by ovalbumin (OVA) sensitization and challenge. The asthmatic rats were respectively treated with vehicle PBS or berberine (100 mg/kg or 200 mg/kg) for 28 days. The control rats were treated with PBS. Inflammatory cells in bronchoalveolar lavage fluid (BALF) were counted and the lung inflammation was scored. Levels of NF-κB p65 (mRNA and protein), phosphorylated NF-κB p65 (p-NF-κB p65), inhibitory κB alpha (IκBα) (mRNA and protein) and phosphorylated IκBα (p-IκBα), as well as NF-κB p65 DNA-binding activity, were measured to assess the activity of NF-κB signaling pathway. Levels of the downstream inflammatory mediators of NF-κB signaling, IL-1β, IL-4, IL-5, IL-6, IL-13 and IL-17 in BALF, were measured. Besides, the serum levels of OVA-specific immunoglobulin (Ig)E were measured.Results showed that OVA increased the number of inflammatory cells in BALF, elevated lung inflammation scores, enhanced the NF-κB signaling activity and promoted the production of IgE in rats. Berberine dose-dependently reversed the alterations induced by OVA in the asthmatic rats.The findings suggested a therapeutic potential of berberine on OVA- induced airway inflammation. The ameliorative effects on the OVA-induced airway inflammation might be associated with the inhibition of the NF-κB signaling pathway.