Relaxant Effects of Syzygium Cumini Leaves on Guinea Pig Tracheal Chains and its Possible Mechanism(s)

Abstract

The  leaves  of  Syzygium  cumini  is  an  attractive  leaves  of  myrtaceae  family . The purpose of this study was investigating experimentally the possible anti asthma activity of macerated and soxhlet extracts of leaves of this plant on tracheal chains of guinea pigs were evaluated. The relaxant effects of 4 cumulative concentrations of macerated and soxhlet extracts (0.25, 0.5, 0.75 and 1.0 W/V) in comparison with saline as negative control and 4 cumulative concentrations of theophylline (0.25, 0.5, 0.75, and 1.0 mM) as positive control were examined on precontracted tracheal chains of two groups of 6 guinea pig by 60 mM KCl (group 1, N=6) and 10 µM methacholine the non-incubated tissues (group 2, N = 6) and tissues incubated  with 1 µM propranolol (group  3, N = 4) ^[15]. Decrease in contractile tone of tracheal chains was considered as relaxant effect. The isolated guinea-pig trachea pre-contracted with KCl, methacholine and tissues incubated with propranolol were used to study the relaxation of macerated and soxhlet extracts of leaves Syzygium cumini. In group 1 experiments only the last one higher concentrations of theophylline and soxhlet extract showed significant relaxant effect compared to that of saline (p<0.001 for both concentrations), which were significantly greater than those of macerated extracts (p<0.001 for all cases).In group 2 experiments only the last two higher concentrations of theophylline and soxhlet extract showed significant relaxant effect compared to that of saline. The effects of two higher concentrations of theophylline in this group were significantly greater than those of macerated and soxhlet extracts (P < 0.01). And in group 2 and 3 experiments both macerated and soxhlet extracts showed concentration-dependent relaxant effects compared to that of saline (p<0.05 to p<0.001 for both extracts).The relaxant effects of macerated and soxhlet extracts in group 1 were significantly lower than those of groups 2 and 3.In group 3 experiment potent relaxant effect was observed.

KEYWORDS: Syzygium cumini, Bronchodilatory Guinea pig. Trachea