Experimental cardiovascular depressant effects of garlic (Allium sativum) dialysate

The objectives of this work were to investigate the effects of a garlic dialysate on diastolic blood pressure (DBP), heart rate (HR) and electrocardiogram (ECG) of anaesthetized dogs and its effects on frequency and tension of isolated rat atria. Garlic dialysate led to a drop in DBP (from 112.5 +/- 3.67 to 70 +/- 3.16 mmHg) and a decrease in HR (from 198 +/- 9.81 to 164 +/- 16.59 beats/min) in a dose-dependent manner. The ECG showed a regular sinus bradycardic rhythm. The addition of garlic dialysate to isolated left rat atria evoked a decrease in tension development. Frequency, measured by spontaneous beating of the right atria, was also reduced. Both effects were dose-dependent. In addition to these effects, the positive inotropism and chronotropism induced by addition of isoproterenol 10(-9) M, were partially antagonized by preincubation of the rat atria with the garlic dialysate. The above findings can be explained by a depressant effect on automaticity and tension development in the heart, suggesting a beta-adrenoceptor blocking action produced by the garlic dialysate.