Numerous studies have demonstrated the health benefits of fruits, vegetables, spices and herbs. For instance, consuming a clove of garlic (or equivalent) decreases cholesterol levels and attenuates hypertension. Previous studies in our laboratory have shown that broccoli sprouts rich in glucoraphanin, a precursor of a potent phase 2 protein inducing isothiocyanate sulforaphane, decreases oxidative stress and ameliorates hypertension. The question this study addressed was the importance of a food matrix in causing these beneficial effects, i.e., can one see the same effects by administration of sulforaphane alone? Sulforaphane (5, 10 and 20 μMoles/Kg) was administered by daily gavage to 5-wk old Spontaneously Hypertensive Stroke Prone rats (SHRsp) for 4 months. Blood pressure was measured weekly by tail cuff and at the end of the experiment by an external catheter inserted into the carotid artery in anesthetized animals. For comparison, age-matched normotensive Sprague Dawley (SD) rats were treated in the same manner. SHRsp control rats had significantly higher Systolic Blood Pressure (SBP) (179.9 ± 4.3 mm Hg) than control SD rats (83.98 ± 1.69). Sulforaphane treatment significantly lowered SHRsp blood pressure to 157.7 ± .21. There was no effect of sulforaphane treatment on SD rat SBP (93.9 ± 4.26). We conclude that the health benefit previously demonstrated in our laboratory is due to sulforaphane.
University of Saskatchewan, Saskatoon, Canada