Effect of Oryza sativa Extract on the Progression of Airway Inflammation and Remodeling in an Experimental Animal Model of Asthma

Abstract

Airway inflammation and remodeling in chronic asthma are characterized by airway eosinophilia, hyperplasia of smooth muscle and goblet cells, and subepithelial fibrosis. The present study was undertaken to evaluate the effects of DA-9201, an ethanolic extract of black rice (Oryza sativa L.), on airway inflammation and remodeling in a murine model of chronic asthma. BALB/c mice sensitized to ovalbumin (OVA) were chronically challenged with aerosolized OVA for 6 weeks. DA-9201 (30, 100, or 300 mg/kg) or dexamethasone (3 mg/kg) was orally administered during the last 4 and 2 weeks, respectively. Airway inflammation, lung pathology by histomorphometry and immunohistochemistry, IgE level and Th2 cytokines were evaluated. The OVA-treated mice showed extensive eosinophilia, chronic inflammatory responses and characteristics of airway remodeling including subepithelial fibrosis, smooth muscle hypertrophy, and goblet cell hyperplasia. As compared to the OVA-treated control group, treatment with DA-9201 resulted in significant reductions in the accumulation of eosinophils in peribronchial areas, chronic pulmonary inflammation and progression of airway remodeling. Furthermore, DA-9201 significantly reduced total serum and BALF IgE levels and Th2 cytokines. These results indicate that DA-9201 may play an important role in attenuating the progressing of airway inflammation and remodeling and suggest the potential benefits of DA-9201 in prevention or treatment of asthma.

Abbreviations

OVA:ovalbumin

BALF:bronchoalveolar lavage fluid

PAS:periodic acid - Schiff

α-SMA:α-smooth muscle actin

BSA:bovine serum albumin

PBS:phosphate buffered saline

EDTA:ethylenediaminetetraacetic acid

H & E:hematoxylin and eosin

ELISA:enzyme linked immunosorbent assay

IL:interleukin

Penh:enhanced pause

IgE:immunoglobulin E

MT:masson's trichrome

Key words

Chronic asthma - pulmonary inflammation - airway remodeling - Oryza sativa

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