Effect of Dihydroartemisinin on contractility to Drugs in isolated smooth muscle Preparations in guinea pig in vitro models

This study was aimed at evaluating the effect of Dihydroartemisinin (DHA)on contractility to drugs in ileum isolated smooth muscle preparations in guinea pigs using in Vitro experimental procedures / standard protocols in an organ bath set up. dihydroartemisinin (1.0 x 10 - 8 - 1.0 x 10 – 5mg/mL) when applied alone and separately excited marked variable effects on guinea pig ileum . In some preparation it showed no response, while in others it produced slight phasic contraction when external calcium (Ca2+) ion was introduced. The slight phasic contractile activity was abolished by verapamil (5x10-3mg/mL). Dihydroartemisinin (1.0 x 10 - 6 - 1.0 x 10 – 5mg/mL) caused marked significant induced contraction – dependent inhibition of acetylcholine, potassium chloride and histamine in depolarizing tyrode solution (p < 0.05).The Inhibitory response maxima of dihydroartemisinin on acetylcholine induced contraction is 17.0±0.1 mm(65.56% inhibition) ; and is moderate when compared to the inhibitory effect of atropine (10-5 M). The result shows that dihydroartemisinin seems to act via non-specific receptor mechanism, with appreciable calcium channel blocking activity and it is safe at therapeutic doses.