EVALUATION OF BRONCHIAL SMOOTH MUSCLE RELAXANT ACTIVITY OF FLUPIRTINE IN EXPERIMENTALLY INDUCED ASTHMA IN GUINEA PIGS

Objectives: The study aimed at evaluating the broncho-relaxant effect of the test drug Flupirtine in experimentally induced Asthma in Guinea pigs & compares its efficacy with the Standard. Materials and Methods: Guinea pigs of both sexes weighing around 350-400 gm were randomly divided into 3 groups of 6 animals each. Groups were categorised into Control, Standard and test groups. Animals serving as controls received 10 ml/kg body weight of Normal saline; Standard group received 4.5 mg/kg body weight of salbutamol & the test group received the test drug flupirtine in doses of 46.5 mg/kg of body weight. All the compounds were administered once a day, per orally, through a gavage tube for 5 days. On day 5 experimental bronchial asthma was induced by exposing animals to 0.25% histamine acid phosphate under constant pressure (40mm/Hg) in an aerosol chamber. Animals exposed to histamine aerosol developed progressive dyspnoea. Pre-convulsive time (PCT) was determined from the time of exposure to onset of dyspnoea, immediately before the appearance of convulsions. Greater the PCT more is the bronchial smooth muscle relaxant effect. Results: There was a significant increase in Pre-convulsive time in the test group when compared to the control group suggesting bronchial smooth muscle relaxant activity of the test drug Flupirtine. Conclusion: Flupirtine capable of mediating a reduction in contractile & inflammatory responses would be a promising drug combining broncho-dilatation with anti-inflammatory action. However further preclinical & clinical studies are warranted.