Antitussive Effects of L-Ephedrine, Amygdalin, and Makyokansekito (Chinese Traditional Medicine) using a Cough Model Induced by Sulfur Dioxide Gas in Mice

Abstract

A cough model induced by sulfur dioxide gas was devised for use with mice. In this method, the ED₅₀ of morphine hydrochloride was 1.58 mg/kg p. o. and that of codeine phosphate was 10.28 mg/kg p. o. Using the method established, L-ephedrine hydrochloride, 0.4, 4.0 and 40 mg/kg p. o., inhibited the cough induction in a dose-dependent manner and amygdalin, 1.0, 10 and 100 mg/kg p. o., also inhibited the cough induction. On the other hand, treatment of Makyokansekito, 162 mg/kg p. o., which contained Ephedrae herba (L-ephedrine, 4.6 mg/kg) and Armeniacae semen (amygdalin, 8.4 mg/kg) as component, showed stronger antitussive effects than the individual crude drugs.