Dendrobium officinale Polysaccharides Attenuate Cigarette Smoke-induced Airway Inflammation in vivo.

Abstract

Introduction: Polysaccharides extracted from Dendrobium officinale (DOP), a valuable traditional Chinese Medicine herb, have antioxidant and anti-inflammatory effects. This study aimed to determine whether DOP treatment has any therapeutic effect on cigarette smoke (CS)–induced airway inflammation in a rat passive smoking model. Methods: Sprague-Dawley rats were exposed to either sham air or CS generated by SCIREQ inExpose inhalation exposure system for 1 hour per day for 56 days. From day 29, rats were given DOP or N-acetylcysteine (NAC, as a positive control) by oral gavage. After the last exposure, rats were sacrificed and bronchoalveolar lavage fluid (BAL), blood and lung tissues were collected for further assays. Results: Complete blood count test showed that CS exposure significantly elevated lymphocytes and monocytes, which was reversed by NAC or DOP treatment. Treatment with NAC or DOP also inhibited CSinduced elevation of macrophages and neutrophils in BAL. In support, DOP treatment significantly inhibited CS-induced elevation of serum and lung CINC-1 levels. However, DOP and NAC significantly attenuated CSinduced elevation of malondialdehyde level in lung. Furthermore, DOP showed inhibition of CS-induced NFkappaB and MAPK (ERK and p38) activation in lung. Conclusion: Dendrobium officinale attenuated smoking-related airway inflammation via the inhibitory effect on NF-kappaB and MAPK signalling pathway in a rat model of passive smoking, which may have beneficial effect for patients with chronic obstructive pulmonary disease. Acknowledgement: This study was supported by Hong Kong Health and Medical Research Fund (HMRF 15161911)