ABSTRACT

Coughing is an important defensive reflex that enhances clearance of secretions and particulates from the airways and protects from aspiration of foreign materials (Irwin et al., 1990). Cough serves as an important protective role in the airways and lungs, but in some conditions, it may become excessive, nonproductive and harmful to the airway mucosa. Citric acid induced cough in guinea pig was examined using Nadig and Laxim (2005) modified by Ozolua, et al., 2019. The guinea pigs were placed individually in a nebuliser chamber and exposed to citric acid aerosol for 10min. 25 animals gave 10 bouts of cough and above and were selected for the study. The pulverized seeds were extracted with 70% ethanol. The animals were grouped into five groups of five animals each.

Group one was given distilled water only, Group two 25mg/kg of Kolaviron,

Group three given 50mg/kg of Kolaviron, Group four given 100mg/kg and Group five given 25mg/kg of the standard drug, dihydrocodeine. The result obtained showed that 25mg/kg, 50mg/kg, 100mg/kg of Kolaviron and dihydrocodeine (25mg/kg) reduces the number of cough bouts and increases the percentage cough suppression when compared to control. The treatment group 25mg/kg and 100mg/kg were statistically significant when compared to control (**P<0.01). The treatment group 50mg/kg and the standard drug were statistically significant when compared to control (*P<0.05). Citric acid acts as a tussigenic agent, which when inhaled stimulates transient receptor on the C sensory fibers causing release of tachykinins which stimulates bronchoconstriction and mucus secretion (Helms et al., 2008). The mechanism of action of dihydrocodeine is that it binds to opioid receptors in the respiratory tract hence suppressing cough reflex by inhibiting bronchoconstriction and mucus secretion (Akil et al., 2004).