Blond and blood juice supplementation in high fat diet fed mice: effect on antioxidant status and DDAH/ADMA pathway

Abstract

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease spread throughout the world. The most frequent causes of death in NAFLD patients are due both to liver and cardiovascular damage. Several pathways, including the dimethylarginine dimethylaminohydrolase (DDAH)/asymmetric dimethylarginine (ADMA) pathway, are involved in the pathogenesis of NAFLD. It has been reported that ADMA plasmatic levels are increased in patients with hepatic dysfunction such as NAFLD. Although many studies demonstrated that some foods are effective in the treatment of NAFLD, few studies have evaluated their effects with respect to the prevention of the disease. It has been reported that sweet orange juice (OJ) consumption may be associated with potential health benefits. However, some varieties of sweet orange are more effective than others. The aim of the present paper was to investigate the effect of blond and blood sweet orange juice in prevention of NAFLD by evaluating its ability to improve liver steatosis in mice with diet-induced obesity, reducing oxidative stress and affecting the DDAH/ADMA pathway. Results obtained in our experimental conditions evidenced that blood orange juice rather than blond orange juice was more effective. Blood orange juice or blond orange juice enriched in anthocyanins may represent a promising dietary option for the prevention of fatty liver disease.

Fig. 1. Effects of blond and blood sweet orange juice on body weight during the 12 weeks period. Body weight was markedly increased in mice fed high-fat diet (HFD) and was decreased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. *p < 0.05 vs. HFD + water.

Fig. 2. Effects of blond and blood sweet orange juice on liver triglycerides content. Liver triglycerides content was markedly increased in mice fed high-fat diet (HFD) and was decreased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.05 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water.

Fig. 3. Effects of blond and blood sweet orange juice on liver lipid hydroperoxide (LOOH) levels. LOOH levels were markedly increased in mice fed high-fat diet (HFD), were mildly decreased to the levels of low fat diet mice by blond sweet orange juice and were significantly decreased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.005 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water; **p < 0.005 vs. HFD + water.

Fig. 4. Effects of blond and blood sweet orange juice on liver non-proteic thiol group (RSH) levels. RSH levels were markedly decreased in mice fed high-fat diet (HFD), were mildly increased to the levels of low fat diet mice by blond sweet orange juice and were significantly increased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.005 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water; **p < 0.005 vs. HFD + water.

Fig. 5. Effects of blond and blood sweet orange juice on liver reactive oxygen species (ROS) levels. ROS levels were markedly increased in mice fed high-fat diet (HFD), were mildly decreased to the levels of low fat diet mice by blond sweet orange juice and were significantly decreased to the levels of low fat diet mice by blood sweet orange juice; #p < 0.005 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water; **p < 0.005 vs. HFD + water.

Fig. 6. Effects of blond and blood sweet orange juice on liver sterol response element binding protein-1c (SREBP-1c) expression. SREBP-1c expression was markedly increased in mice fed high-fat diet (HFD) and was significantly decreased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.05 vs. standard diet (SD) + water; *p < 0.005 vs. HFD + water.

Fig. 7. Effects of blond and blood sweet orange juice on liver dimethylarginine dimethylaminohydrolase-1 (DDAH-1) expression. DDAH-1 expression was markedly decreased in mice fed high-fat diet (HFD) and was significantly increased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.05 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water.

Fig. 8. Effects of blond and blood sweet orange juice on liver dimethylarginine dimethylaminohydrolase-1 (DDAH-1) activity. Enzymatic activity was determined by measuring l-citrulline formation. DDAH-1 activity was markedly decreased in mice fed high-fat diet (HFD) and was significantly increased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.05 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water.

Fig. 9. Effects of blond and blood sweet orange juice on liver asymmetric dimethylarginine (ADMA) levels. ADMA levels were markedly increased in mice fed high-fat diet (HFD) and was significantly decreased to the levels of low fat diet mice by blood sweet orange juice. Values are mean ± standard deviation (S.D.) of at least three independent experiments. #p < 0.005 vs. standard diet (SD) + water; *p < 0.05 vs. HFD + water.