Myocardial effects of flavonoids from crataegus species

摘要: The influence of the main flavonoids from Crataegus species (hawthorn, Rosaceae) on coronary flow, heart rate and left ventricular pressure as well velocity contraction relaxation was investigated in Langendorff perfused isolated guinea pig hearts at a constant 70 cmH2O. Drug action evaluated concentration range 10(-7) to 5 x 10(-4) mol/l. An increase flow caused by O-glycosides luteolin-7-glucoside (186%), hyperoside (66%) rutin an (positive lusitropism) (104%), (62%) (73%) were major effects observed maximum 0.5 mmol/l. Furthermore, slight positive inotropic rise seen. Similar but less intensive actions found with C-glycosides vitexin, vitexin-rhamnoside monoacetyl-vitexin-rhamnoside. Possible beta-adrenergic activities could be excluded addition propranolol fixed concentrations 10(-8) 10(-5) Moreover, pretreatment animals reserpine (7 mg/kg) did not myocardial activity (10(-4) mol/l). As previous experiments showed inhibition 3',5'-cyclic adenosine monophosphate phosphodiesterase, results suggest this enzyme possible underlying mechanism cardiac species.