Ginger and turmeric lipid-solubles attenuate heated oil-induced cardio-hepatic oxidative stress via the up-regulation of nuclear factor erythroid 2-related factor 2 and decrease blood pressure in rats

Deep-fried vegetable oils are reused multiple times to save costs, and their chronic consumption may cause organ dysfunction. In this study, we assessed the modulatory effects of lipid-solubles from ginger and turmeric that may migrate to oils during heating, on the cardio-hepatic antioxidant defence response and blood pressure in rats. Male Wistar rats were fed with: (1) control (native rapeseed (N-CNO) or native sunflower (N-SFO)) oil, (2) heated (heated rapeseed (H-CNO) or heated sunflower (H-SFO)) oil and (3) heated oil with ginger or turmeric (heated rapeseed oil with ginger (H-CNO + GI) or heated rapeseed oil with turmeric (H-CNO + TU), heated sunflower oil with ginger (H-SFO + GI) or heated sunflower oil with turmeric (H-SFO + TU)) for 120 d. Oxidative stress (OS) markers, antioxidant enzymes, nitric oxide synthase-2 (NOS-2), intercellular adhesion molecule-1 (ICAM-1), nuclear factor erythroid 2-related factor 2 (NRF-2), markers of hepatic and cardiac function and blood pressure were assessed. Feeding heated oils (H-CNO or H-SFO) (1) increased OS markers, NOS-2 and ICAM-1 expression; (2) decreased antioxidant enzyme activity and NRF-2 level; (3) increased marker enzymes of hepatic and cardiac function and (4) increased systolic and diastolic blood pressure significantly (P < 0·05), when compared with respective native oils (N-CNO or N-SFO). However, feeding oils heated with ginger or turmeric positively countered the changes induced by heated oils. Consumption of repeatedly heated oil causes cardio-hepatic dysfunction by inducing OS through NRF-2 down-regulation. Lipid-solubles from ginger and turmeric that may migrate to oil during heating prevent the oxidative stress and blood pressure triggered by heated oils in rats.

Comparative effects of repeatedly heated cooking oils on tissue lipid peroxidation and antioxidant status in cholesterol-fed Sprague Dawley rats

Purpose The purpose of this paper is to compare the effects of repeatedly heated coconut oil, mustard oil and sunflower oil on antioxidant status in cholesterol-fed Sprague Dawley rats. Design/methodology/approach The test oils were heated at 210 ± 10°C for 15 h. Male Sprague Dawley rats were divided into six groups of six animals each. In total, 15% fresh/heated oils and 1% cholesterol were mixed with the experimental diet and fed to the animals for 60 days. Findings Chemical analysis revealed that repeated heating of oils resulted in changes in fatty acid composition and elevated lipid peroxidation, the effects being lower in heated coconut oil. Body weight gain significantly decreased in heated coconut oil (p = 0.02), heated mustard oil (p = 0.022) and heated sunflower oil (p = 0.001) fed animals. Malondialdehyde level was significantly increased (p = 0.001) in tissues of heated oils fed animals. Concentration of protein oxidation products was significantly increased (p = 0.001) in heated oils fed animals. Activities of antioxidant enzymes were decreased (p = 0.001) in heated oils fed animals. Total thiols were decreased (p = 0.001) in tissues of animals that were fed heated oils. Animals that were fed heated mustard oil and heated sunflower oil showed lower antioxidant levels and higher oxidation products when compared to those fed heated coconut oil. Originality/value Studies comparing the effects of thermally oxidized oils that vary in fatty acid composition are rare. The effects of fresh and heated oils that vary in fatty acid constitution, namely, coconut oil, mustard oil and sunflower oil, in cholesterol-fed rats are studied.

Correction: Che Idris, C.A., et al. Effect of Consumption Heated Oils with or without Dietary Cholesterol on the Development of Atherosclerosis. Nutrients 2018, 10, 1527

The authors wish to make the following change to their paper (Che Idris et al. [...]

Effect of Consumption Heated Oils with or without Dietary Cholesterol on the Development of Atherosclerosis

Heating oils and fats for a considerable length of time results in chemical reactions, leading to the aggravation of a free radical processes, which ultimately contributes to atherosclerosis. Our study focused on elucidating the effect of feeding heated oils with or without dietary cholesterol on the development of atherosclerosis in rabbits. We heated palm olein and corn oil at 180 °C for 18 h and 9 h per day, respectively, for two consecutive days. Next, 20 male rabbits were divided into four groups and fed the following diet for 12 weeks: (i) heated palm olein (HPO); (ii) HPO with cholesterol (HPOC); (iii) heated corn oil (HCO); and (iv) HCO with cholesterol (HCOC). Plasma total cholesterol (TC) was significantly lower in the HCO group compared to the HCOC group. Atherosclerotic lesion scores for both fatty plaques and fatty streaks were significantly higher in the HCO and HCOC groups as compared to the HPO and HPOC groups. Additionally, fibrous plaque scores were also higher in the HCO and HCOC groups as compared to the HPO and HPOC groups. These results suggest that heated palm oil confers protection against the onset of atherosclerosis compared to heated polyunsaturated oils in a rabbit model.