Effects of an ethanolic extract of mulberry fruit on blood pressure and vascular remodeling in spontaneous hypertensive rats

Mulberry (Morus alba) has been used in traditional oriental medicine since ages. Recently, it has been reported that mulberry produces hypotensive effects through the eNOS signaling pathway. However, the mechanism underlying the hypotensive effects of mulberry is not entirely clear. Moreover, the effects of mulberry on vascular remodeling events such as hyperplasia, an important etiology in the pathogenesis of hypertension and arteriosclerosis, are also ambiguous. Here, we hypothesized that an ethanolic extract of mulberry fruit (EMF) has beneficial effects on vascular remodeling and produces hypotensive effects. The effects of a 6-week oral administration of EMF were examined in spontaneously hypertensive rats (SHRs). The animals were divided into four groups: normotensive control (Wistar Kyoto rats), non-treated SHR, low-dose (100 mg/kg) EMF-treated SHR, and high-dose (300 mg/kg) EMF-treated SHR. Our results showed that the EMF-diet normalizes hypertension in SHRs in a dose-dependent manner, by preventing smooth muscle proliferation, thickening of the tunica media, and vascular hyper-reactivity. The endothelial functions were not substantially affected by the EMF diet in our experimental setting. In conclusion, we suggest that the mulberry fruit could act as a food supplement for reducing blood pressure in hypertensive subjects through its effects on smooth muscle proliferation and vascular contractility.