Influence of rutin on the effects of neonatal cigarette smoke exposure-induced exacerbated MMP-9 expression, Th17 cytokines and NF-ҡB/iNOS-mediated inflammatory responses in asthmatic mice model
Li-Li Liu1, Yan Zhang1, Xiao-Fang Zhang2, and Fu-Hai Li1,*
1Children’s Medical Center, Qilu Hospital of Shandong University, 2Department of Pathology, Shandong University of Medicine, Jinan, Shandong 250012, P.R.China
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Allergic asthma is one of the most enduring diseases of the airway. The T-helper cells and regulatory T-cells are critically involved in inflammatory responses, mucus hypersecretion, airway remodelling and in airway hyper-responsiveness. Cigarette smoke (CS) has been found to aggravate inflammatory responses in asthma. Though currently employed drugs are effective, associated side effects demand identification and development of novel drugs with negligible or no adverse effects. Rutin, plant-derived flavonoid has been found to possess antioxidant and anti-inflammatory effects. We investigated the ability of rutin to modulate T-cells and inhibit inflammation in experimentally-induced asthma in cigarette smoke exposed mice. Separate groups of neonatal mice were exposed to CS for 10 days from post-natal days 2 to 11. After 2 weeks, the mice were sensitized and challenged with ovalbumin (OVA). Treatment group were given rutin (37.5 or 75 mg/kg body weight) during OVA sensitization and challenge. Rutin treatment was found to significantly inhibit cellular infiltration in the airways and Th2 and Th17 cytokine levels as well. Flow cytometry revealed effectively raised CD4+CD25+Fox3+ Treg cells and supressed Th17 cell population on rutin treatment. Airway hyper-responsiveness observed following CS and OVA challenge were inhibited by rutin. NF-ҡB and iNOS, chief regulators of inflammatory responses robustly activated by CS and OVA were down-regulated by rutin. Rutin also inhibited the expression of matrix metalloproteinase 9, thereby aiding in prevention of airway remodelling in asthma thereby revealing to be a potent candidate in asthma therapy.
Keywords: Asthma, Cigarette smoke, Matrix metalloproteinase, Regulatory T cells, Rutin