Addition of Citrus Leaf Extract into Frying Oil Prevents Hypertension and Improves Vascular Reactivity in Heated Oil-Fed Rats

Abstract

The use of repeatedly heated frying oil is hazardous to health, due to oxidative process that occurs in the oil. Addition of an additive with antioxidant property could lessen the detrimental effects of repeated frying in the oils. Citrus leaf extract (CLE) supplementation was reported to possess antioxidant and blood pressure-lowering properties. Our study aimed to determine the effects of CLE addition into frying oil in rats fed with repeatedly heated oil diet. Seven groups of male Sprague-Dawley rats were given fresh and heated oil diets (five-time-and tentime-heated palm oil), with and without the CLE addition for 16 weeks. CLE addition decreased peroxide value and augmented the total phenolics content in the heated oils. CLE addition reversed the negative effects of heated oil on nitric oxide level, systolic blood pressure, and vascular reactivity. In conclusion, these findings show that CLE has the ability to reduce oxidative damage caused by thermal degradation in frying oil and subsequently lowers the risk of hypertension in rats that consumed heated oil.

Gynura procumbens ethanol extract improves vascular dysfunction by suppressing inflammation in postmenopausal rats fed a high-fat diet

“…This study showed that systolic blood pressure (SBP) in the postmenopausal (PM) group increased following consumption of high-fat diet most probably due to the presence of peroxide radicals, and other ROS generated in the multiple-heated oil in the diet. A similar finding was reported previously, proving that multiple-heated oil in the diet elevated lipid peroxidation exceeding the maximum limit of peroxide value (10 mEq/kg) in foods (Ng et al 2012;Suhaimi et al 2020). However, the supplementation with GP extract at the dose of 250 and 500 mg/kg managed to reduce blood pressure to the normal level, and the dose of 500 mg/kg GP showed the potential effect as the ATV, the positive control.…”

“… 2012 ; Suhaimi et al. 2020 ). However, the supplementation with GP extract at the dose of 250 and 500 mg/kg managed to reduce blood pressure to the normal level, and the dose of 500 mg/kg GP showed the potential effect as the ATV, the positive control.…”

“…Relaxation responses to Ach or SNP were plotted as the percentage relaxation versus log concentration of Ach or SNP. The pEC50 (-log of median effective concentration) and percentage relaxations at the highest concentration (Rmax) were calculated from the graph (Machha and Mustafa 2005;Muharis et al 2010;Suhaimi et al 2020).…”

Potential Therapeutic Effects of Citrus hystrix DC and Its Bioactive Compounds on Metabolic Disorders

“…It is possible that the beneficial effect was conferred by the improvement in vascular response due to preserved plasma nitric oxide level. The groups that were fed the extract-treated oils also showed better organization of vascular elastic lamellae, smaller aortic tunica intima to tunica media ratio, and lower expression of vascular cell adhesion molecule-1 [63]. The findings indicated that the extract prevented oxidation in the oils upon heating, thus increasing their stability and antioxidant content.…”

“…Heating causes chemical changes like thermal oxidation and polymerization in the oil, leading to a configuration change in the fatty acids from cis to trans [61]. Addition of C. hystrix leaf extract at 1% into frying oils that were heated five and ten times reduced peroxide levels and increased the total phenolic content of the oils [63,64] (Table 4). Reduction in the oxidized content of the oil by the addition of the extract prevented the elevation of blood pressure in rats that were fed the heated oils for 16 weeks, starting on week 4.…”