Assessment of the bronchodilator effect of “2-(2,3-dihydroxyphenyl)-4-ethylchroman-3,5,6-triol’’ isolated from Ficus trichopoda (Baker, 1883) (MORACEAE) leaves

This study aims to investigate the mechanism(s) implicated in the bronchodilation effect exerted by “2-(2,3-dihydroxyphenyl)-4-ethylchroman-3,5,6-triol“isolated from Ficus trichopoda (Kaker, 1883) (MORACEAE) leaves. This molecule was isolated from ethyl acetate extract fraction followed by chromatography. It was tested on isolated trachea of guinea pig pre contracted with histamine 10 µM. injected in the bath in a cumulative manner, this molecule relaxes completely the organ with EC₅₀ of 9,74.10^-7 M. Pre incubating the organ in a bath containing the isolate at concentrations of 4.81.10^-5 M, 9.62.10^-5 M,  1.44.10^-4 and  1.92.10^-4 M induces a right shift of the concentration effect curves of histamine with an increase of histamine EC₅₀ from 5.62.10^-7 M in the absence of the isolate to 5.81.10^-6, 6.91.10^-6, 7.92.10^-6 and 8.1.10^-5 M in its presence (p<0.05). These results indicate a competitive antagonism between histamine and the isolate.