Interestingly, our results demonstrated that MA restores
the vascular response of diabetic rats to both vasodilator and
vasoconstrictor. This effect of MA is probably due to its
hypoglycemic and also antioxidant activities. Because we
found that MA-treated diabetic rats had a significant lower
MDA concentration in various tissues than that of nontreated
diabetic rats especially in the aortic tissue (Table 2), the
significant increased MDA concentrations in various tissues
in chronic diabetic rats point to ROS-mediated cellular
damage, denoting the presence of oxidative stress in chronic
diabetes[22]. Mulberry leaf extract components, especially
flavonoids (ie, quercetin, rutin, and isoquercitrin), possess
the free radical scavenging effect, showing the possibility of
antioxidant activity [23].