Aurantio-Obtusin Suppresses Airway Inflammation and Serum ICAM-1 Expression in Guinea Pig Allergic Asthma Model

Aurantio-obtusin is a trihydroxyanthraquinone found in the seeds of Cassia tora and Cassia obtusifolia. Its neuroprotective, anti-inflammatory, anti-allergic, and antioxidant potential has been documented in multiple studies. While previous reports mention its potential as an antiasthma agent, its effects on allergen-induced airway inflammation have not been explored.

Our study reports on the mechanisms by which aurantio-obtusin exerts its effects on underlying inflammation in experimentally-induced allergic asthma. The effect of aurantio-obtusin pretreatment on molecular and histological changes in guinea pig lungs when challenged with aerosolized ovalbumin was assessed.

Our results showed that aurantio-obtusin significantly reduced ovalbumin (OVA)-induced increase in serum OVA-specific immunoglobulin E (OVA-sIgE) and intercellular adhesion molecule (ICAM)-1. Aurantio-obtusin further suppressed inflammatory cytokine expression (IL-8, TNF-α, IL-6 and thymic stromal lymphopoietin) as well as malondialdehyde, a product of oxidative stress in bronchial lavage. The histopathological assessment showed a reduced transit of inflammatory cells and reduced deposition of collagen in the lungs of aurantio-obtusin-treated guinea pigs.

Overall, the data suggests that aurantio-obtusin mitigated ovalbumin-induced airway inflammation by impeding the production of OVAsIgE and suppressing levels of key pro-inflammatory cytokines. Our findings suggest that aurantio-obtusin has potential benefits in the management of allergic airway inflammation in type 2 asthma.