IN VIVO AND EX VIVO STUDIES ON ANTISPASMODIC EFFECT OF QUERCETIN ON AIRWAY SMOOTH MUSCLE OF NORMAL AND OVALBUMIN INDUCED ASTHMATIC RATS
Loading...
Date
2012-11
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
SRI VENKATESWARA VETERINARY UNIVERSITY TIRUPATI – 517 502. (A.P) INDIA
Abstract
ABSTRACT :
Asthma is a chronic disease characterized by exaggerated airway smooth muscle contraction to various stimuli and manifested by symptoms viz. recurrent episodes of wheezing, breathlessness, chest tightness and coughing. Quercetin is a polyphenolic flavonoid substance present abundantly in red onions, apples, red wine and tea leaves with anti-inflammatory, anti-allergenic, and antioxidant properties. The present study was carried out to explore anti spasmodic effect of quercetin on rat tracheal smooth muscle in normal and ovalbumin sensitized rats. The study was conducted in four groups of wistar albino rats. Group I consisted apparently normal rats where as rats that are apparently normal in group II received quercetin (20 mg/kg, P.O) for 14 days. In group III rats were sensitized with ovalbumin for experimental induction of allergy and asthma. Where as in group IV rats were sensitized with ovalbumin and also received quercetin (P.O) for 14 days. Rats were sacrificed and tracheal rings were isolated for functional studies using polygraph. Both lungs and tracheal rings were collected and subjected to histological studies. Airway hyper responsiveness in ovalbumin sensitized rats was manifested by decreased EC50 value (4.57 х 10-8M) of carbachol cumulative dose contractile response compared to normal group (1.58 х 10-7M). The mean EC50 value for cumulative dose contractile response of carbachol on tracheal smooth muscle obtained from ovalbumin sensitized with simultaneously quercetin treated rats (1.9 х 10-7M) is significantly higher than ovalbumin sensitized group (4.57 х 10-8M) and almost similar to normal (1.58 х 10-7M) group. This showed the potent antagonizing effect of quercetin against airway hyperresponsiveness in asthmatic condition. Quercetin relaxed the tracheal smooth muscle of normal (IC50: 5.62 х 10-7M) and ovalbumin sensitized rats (1.99 х 10-7M) that were pre contracted with carbachol. Quercetin feeding in ovalbumin sensitized rats decreased the IC50 of quercetin on carbachol induced contraction than normal. Alterations in histological architecture of trachea and lung were observed in ovallbumin sensitized rats. In group IV that received quercetin along with ovalbumin sensitization the histological changes are minimized and protective lesions for epithelium were pronounced. It was apparent from the study that quercetin has antispasmodic effect on airway smooth muscle in normal and ovalbumin induced asthmatic rats and gives protection from allergic inflammatory conditions like asthma.
Description
THESES
Keywords
null