Therapeutic potential and mechanism of Dendrobium officinale polysaccharides on cigarette smoke-induced airway inflammation in rat

Abstract

Chronic obstructive pulmonary disease (COPD) is among the leading causes of death worldwide, and is characterized by persistent respiratory symptoms and airflow limitation due to chronic airway inflammation. Cigarette smoking is a major risk factor for COPD. This study aims to determine the therapeutic effects of polysaccharides extracted from Dendrobium officinale (DOPs), a valuable traditional Chinese Medicinal herb, on cigarette smoke (CS)-induced airway inflammation in a rat passive smoking model. Male Sprague-Dawley rats were exposed to CS or sham air (SA) as control for a 56-day period. On Day 29, rats were subdivided and given water, DOPs or N-acetylcysteine (NAC) via oral gavage on a daily basis for the remaining duration. DOPs reduced CS-induced oxidative stress as evidenced by reducing malondialdehyde (MDA) levels in the lung. DOPs also exerted potent anti-inflammatory properties as evidenced by a reduction in the number of lymphocytes and monocytes in serum, significantly attenuating infiltration of inflammatory cells in lung tissue, as well as pro-inflammatory mediators in serum, bronchoalveolar lavage (BAL) and lung. Additionally, DOPs inhibited the CS-induced activation of ERK, p38 MAPK and NF-κB signaling pathways. These findings suggest that DOPs may have potentially beneficial effects in limiting smoking-related lung oxidative stress, and inflammation mediated via the inhibition of MAPK and NF-κB signaling pathways in smokers, without or with COPD.