Pheretima aspergillum decoction suppresses inflammation and relieves asthma in a mouse model of bronchial asthma by NF-κB inhibition

Ethnopharmacological relevance and aim of the study: Guang-Pheretima, the live form of the earthworm Pheretima aspergillum, is a traditional Chinese medicine commonly used for the treatment of asthma, cough, stroke, epilepsy and other diseases due to its anti-inflammatory, anti-asthmatic, anti-seizure, thrombolytic and diuretic properties. Although Guang-Pheretima is effective in the relief of asthma, its pharmacological activity and the underlying molecular mechanisms are not fully understood. Hence, we investigated the effects of a Pheretima aspergillum decoction (PAD) against inflammation in a model of ovalbumin (OVA)-induced asthma in BALB/c mice, as well as the nuclear factor-kappa B (NF-kappa B) pathway involved in this process. Materials and methods: OVA was used to sensitize and challenge the airway of the mice, and PAD was administrated by gavage. We measured airway hyperresponsiveness (AHR) in the mice 24 h following a final methacholine challenge with whole-body plethysmography. The bronchoalveolar lavage fluid (BALF), serum and pulmonary tissues were collected 48 h after the last challenge. The levels of inflammatory factors and the related mRNAs were determined by enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (RT-PCR), respectively. The number of differential inflammatory cells in the BALF was counted. Serum total and OVA-specific IgE levels were measured with ELISA. The activation of NF-kappa B signaling in the lung was detected by western blotting. In addition, the lung tissues were stained with hematoxylin and eosin or periodic acid Schiff stain for histopathological examination. Results: PAD treatment significantly alleviated AHR in the asthmatic mice, decreased the mRNA and protein levels of IL-4, IL-5 and IL-13 and downregulated IgE. In addition, PAD treatment attenuated mucus secretion and infiltration of inflammatory cells in the lung while inhibiting the activation of NF-kappa B signaling. Conclusions: PAD effectively inhibited the activation of NF-kappa B signaling in the lungs of mice with OVA induced asthma, and mitigated AHR and Th2 type inflammatory reactions. Therefore, PAD may serve as a drug candidate for asthma treatment. (C) 2016 Elsevier Ireland Ltd. All rights reserved.