# Magnolia officinalis Rehder & E.H.Wilson. Bark Extract and Magnolol Alleviate Allergic Rhinitis via Modulating NF-κB/MAPK Signaling

## TL;DR

This study shows that Magnolia officinalis bark extract and magnolol reduce allergic rhinitis symptoms by modulating inflammatory pathways in mice.

## Contribution

The study reveals the molecular mechanisms of MOAE and magnolol in alleviating allergic rhinitis via NF-κB/MAPK signaling.

## Key findings

- MOAE and magnolol reduced nasal symptoms and eosinophil infiltration in an AR mouse model.
- Treatment lowered serum histamine and OVA-specific antibodies in allergic mice.
- Network pharmacology and RNA sequencing identified 33 co-regulated genes in NF-κB and MAPK pathways.

## Abstract

Magnolia officinalis Rehder & E.H.Wilson. bark is famous as a traditional herbal medicine used in prescriptions for treating gastrointestinal discomfort, respiratory and inflammatory disorders. Magnolol, one of its principal bioactive constituents, exhibits potent anti-inflammatory and immunomodulatory properties. However, its therapeutic mechanisms in allergic rhinitis (AR) remain to be elucidated. In this study, the anti-allergic effects and molecular mechanisms of M. officinalis bark aqueous extract (MOAE) and magnolol were investigated using an ovalbumin (OVA)-induced AR mouse model. Nasal symptoms, histopathological alterations, and serum inflammatory mediators, including histamine and immunoglobulins (IgE, IgG1, IgG2a), were evaluated to assess efficacy. Both MOAE and magnolol significantly alleviated nasal rubbing and sneezing, reduced eosinophil infiltration and mucus hypersecretion, and improved tissue morphology in nasal and lung sections. Moreover, treatment markedly decreased serum levels of histamine and OVA-specific antibodies. Integrative network pharmacology, RNA sequencing, and molecular docking analyses revealed 33 co-regulated target genes mainly involved in the NF-κB and MAPK signaling pathways, suggesting that modulation of these pathways underlies the observed anti-inflammatory effects. These findings demonstrate that MOAE and magnolol exert protective effects against AR through the regulation of key inflammatory signaling cascades. This study provides modern pharmacological evidence supporting the traditional use of M.
officinalis bark and highlights its potential as a natural therapeutic candidate for AR.