Hepatoprotective and antioxidant effects of lycopene on non-alcoholic fatty liver disease in rat

Abstract

AIMTo evaluate the hepatoprotective effect of lycopene (Ly) on non-alcoholic fatty liver disease (NAFLD) in rat.METHODSA rat model of NAFLD was first established by feeding a high-fat diet for 14 wk. Sixty-five rats were randomly divided into normal group, model group and Ly treatment groups. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides (TG), total cholesterol (TC) in serum and low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), free fatty acid (FFA), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) in liver tissue were evaluated, respectively. While the hepatoprotective effect was also confirmed by histopathological analysis, the expression levels of TNF-α and cytochrome P450 (CYP) 2E1 in rat liver were determined by immunohistochemistry analysis.RESULTSA significant decrease was observed in the levels of serum AST (2.07-fold), ALT (2.95-fold), and the blood lipid TG (2.34-fold) and TC (1.66-fold) in the dose of 20 mg/kg Ly-treated rats (P < 0.01), compared to the model group. Pretreatment with 5, 10 and 20 mg/kg of Ly significantly raised the levels of antioxidant enzyme SOD in a dose-dependent manner, to 90.95 ± 9.56, 109.52 ± 11.34 and 121.25 ± 10.68 (P < 0.05, P < 0.01), as compared with the model group. Similarly, the levels of GSH were significantly increased (P < 0.05, P < 0.01) after the Ly treatment. Meanwhile, pretreatment with 5, 10 and 20 mg/kg of Ly significantly reduced MDA amount by 30.87, 45.51 and 54.49% in the liver homogenates, respectively (P < 0.01). The Ly treatment group showed significantly decreased levels of lipid products LDL-C (P < 0.05, P < 0.01), improved HDL-C level and significantly decreased content of FFA, compared to the model group (P < 0.05, P < 0.01). Furthermore, the Ly-treated group also exhibited a down-regulated TNF-α and CYP2E1 expression, decreased infiltration of liver fats and reversed histopathological changes, all in a dose-dependent manner (P < 0.05, P < 0.01).CONCLUSIONThis study suggests that Ly has a protective effect on NAFLD, down-regulates expression of TNF-α, and that CYP2E1 may be one of the action mechanisms for Ly.

Tomato Juice Supplementation Influences the Gene Expression Related to Steatosis in Rats

“…In developed countries, NAFLD is increasing due to the incidence of obesity, and it is currently more prevalent than alcohol-induced liver disease. Several studies have reported the beneficial effect of dietary carotenoids, particularly lycopene, for the prevention and treatment of steatosis [ 3 , 6 , 7 , 10 ].…”

“…For this reason, it has been recommended for the treatment of NAFLD in the practical clinical guide of the European associations for the study of the liver, diabetes, and obesity (EASL-EASD-EASO) [ 5 ]. The Mediterranean diet combines marine products and grains rich in mono and polyunsaturated fats with fruits and vegetables rich in dietary bioactive antioxidants, such as polyphenols and carotenoids, which have a beneficial effect in the prevention of NAFLD, as has been shown in different animal models [ 1 , 6 , 7 , 8 ]. Interestingly, for non-provitamin A carotenoids, and particularly for lycopene (from tomato) [ 3 , 9 ], there is much experimental evidence on the prevention of steatosis and inflammation in murine models, through different mechanisms, including the scavenging activity of reactive oxygen species.…”

“…In a previous study, we reported that the consumption of tomato juice improves the lipid metabolism in rats with steatosis induced by a fatty diet and acts as a regulator of lipid metabolism improving β-oxidation [ 4 , 10 ]. Moreover, lycopene exerts efficient anti-inflammatory and antiproliferative effects, which also act against NAFLD [ 3 , 7 , 11 ]. The intake of tomato juice by individuals on a hypercholesterolemic and high-fat diet partially recovered amino acid levels in liver, particularly for L-carnitine, which could indicate a better ability to maintain the mitochondrial activity, concerning β-oxidation, and to protect the fatty liver against inflammation and fibrosis [ 10 ].…”

Camellia oleifera seed extract attenuated abdominal and hepatic fat accumulation in rats fed a high-fat diet

“…Overconsumption of dietary lipids leads to abnormal lipid metabolism and increased hepatic fat accumulation, which activates the expression of cytochrome P450 2E1 (CYP2E1) and increases oxidative stress and inflammatory responses in vivo (Jiang et al, 2016;Johann et al, 2006). In addition to the increase in hepatic cytokine levels, adipose tissue can also release adipokines which have certain physiological effects.…”

Role of Dietary Carotenoids in Different Etiologies of Chronic Liver Diseases

“…It can reduce high-fat diet-induced steatohepatitis by reducing oxidative stress to the cells. It has been also shown that incorporation of lycopene in balanced diet prevents NAFLD [67,68]. Lycopene may be a useful functional compound for treating NAFLD by regulating hepatic lipid metabolism [69].…”