Effect of Methanol Extract of Althaea Root on Contractile Function of Rat's Tracheal Smooth Muscle

The sudden involuntary muscular contractions of the air ways is a very common disease in human societies. Study on medical plant extracts to affect contractile activity of the tracheal smooth muscle can be useful manner in control of pulmonary obstructive sickness. This research was designed to determine the effect of Althaeas’ root methanol extract on contractile function of rat tracheal smooth muscle. In this experimental study, 36 tracheas of a healthy and male of 18 Sprague Dawley rats were dissected in 6 groups. The effect of Althaeas’ root methanol extract concentrations (0.2, 0.6, 2.6, 6.6, 14.6, 140.6 µg/ml) and epinephrine (5µ m) in presence and absence of 1μM propranolol under one gram tension based on isometric method was assayed. This assay was recorded in an organ bath containing kerebs-hancelit solution on tracheal smooth muscle contractions by KCl (60 mM) induction. Epinephrine (5 µm) alone and root methanol extract concentrations (0.6 - 140.6 µg/ml) reduced the tracheal smooth muscle contractions induced by KCl (60 mM) dose-dependently. Propranolol couldn’t reduce the antispasmodic effect of root methanol extract concentrations, but it could reduce the antispasmodic effect of Epinephrine on tracheal smooth muscle contractions. Althaeas’ root methanol extract inhibited the tracheal smooth muscle of rat contractions dose dependently, but it seems that β-Adrenergic receptors are not engage in this process. Realizing the mechanism of this process can be useful in treatment of pulmonary obstructive disease.