In this study, along with this line of research, we also showed that high fructose consumption increased the LDL, VLDL and TG levels of plasma as compared with those of the control group.
If fructose-induced hypertension is secondary to an increase in plasma LDL and VLDL levels, then a decrease in the level of these parameters should prevent the rise in BP. Our results are consistent
with this hypothesis, because celery leaves extract improved lipid profile and attenuated the increase in BP. Chronic treatment of rats with a diet high in fructose causes oxidative stress (Tran et al., 2009; Song et al., 2005). Increased formation of reactive oxygen species have been reported to contribute to fructose- induced hypertension.
There is plenty of evidence to show that there is a strong relationship between oxidative stress and hypertension. On the other hand, reduction of oxidative stress by pharmacological doses of some antioxidant agents lowers blood pressure in animals with hypertension, yet it has no effect on blood pressure in normal animals (Vaziri, 2008). It was also reported that fasting plasma concentrations of low density lipoprotein cholesterol and oxidized LDL significantly increased after consuming fructose (Stanhope and Havel, 2010; Chen et al., 2004).
The flavonoid apigenin, one of the components of celery leaves, was shown to express strong antioxidant effects by increasing the activities of antioxidant enzymes and thereby decreasing the oxidative damage to tissues (Lugasi et al.2003; Lugasi et al., 2000). It was also reported that celery leaves juice decreased intensity of lipid peroxidation and increased reduced gluthation (Kolarovic et al., 2009).
In conclusion, according to the findings above, celery leaf extract with its blood pressure and lipid lowering effects, can be considered as an antihypertensive agent in chronic treatment of elevated SBP in rats.