A High-Fat, High-Fructose Diet Induces Antioxidant Imbalance and Increases the Risk and Progression of Nonalcoholic Fatty Liver Disease in Mice.

Excessive fat liver is an important manifestation of nonalcoholic fatty liver disease (NAFLD), associated with obesity, insulin resistance, and oxidative stress. In the present study, the effects of a high-fat, high-fructose diet (HFFD) on mRNA levels and activities of the antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), were determined in mouse livers and brains. The histomorphology of the livers was examined and the state of nonenzymatic reducing system was evaluated by measuring the glutathione system and the lipid peroxidation. Histopathology of the liver showed that fat accumulation and inflammation depended on the period of the HFFD-consumption. The levels of mRNA and enzymatic activities of SOD, CAT, and GPx were raised, followed by the increases in malondialdehyde levels in livers and brains of the HFFD mice. The oxidized GSSG content was increased while the total GSH and the reduced GSH were decreased, resulting in the increase in the GSH/GSSG ratio in both livers and brains of the HFFD mice. These observations suggested that liver damage and oxidative stress in the significant organs were generated by continuous HFFD-consumption. Imbalance of antioxidant condition induced by long-term HFFD-consumption might increase the risk and progression of NAFLD.

Effect of tetrahydrocurcumin on the profiles of drug-metabolizing enzymes induced by a high fat and high fructose diet in mice.

Cytochrome P450 (CYP), a superfamily of hepatic monooxygenase enzymes, catalyzes biotransformation of endogenous compounds and xenobiotics. Modification of CYPs associated with metabolic diseases and continuous consumption of diet with excessive energy levels. Tetrahydrocurcumin (THC) exhibited beneficial effects in metabolic syndromes such as diabetic mellitus and dyslipidemia. The present study aimed to investigate the effects of THC and vitamin E (vitE) on the expression profiles of CYPs in the livers of mice fed with the high fat and high fructose diet. In addition to ad libitum access to commercial regular diet, the high fat and high fructose diet (HFD) group of adult male ICR mice was administered a HFD, which consisted of intragastric administration of hydrogenated soybean oil (1mL/day) and the addition of 20% fructose to the drinking water for 8weeks. During the induction period, subgroups of mice (n=5) were daily intragastrically administered with THC (100 or 200mg/kg/day) or vitE (100mg/kg/day). The expressions of CYP mRNA and protein were quantified using real-time PCR and the levels of these proteins were quantified using immunoblotting. Continuous consuming of high fat and high fructose for 8weeks significantly increased the expressions of Cyp1a1, Cyp1a2, Cyp1b1, Cyp2c29, and Cyp3a11 while THC ultimately normalized these CYPs profiles. In the control mice, most of the investigated CYPs was unchanged by THC, with the exception that the Cyp1a1, Cyp2b9, and Cyp3a11 proteins were elevated. These findings provided additional important information on the effects of THC on diet induced-metabolic dysfunctions. However, drug interactions due to the use of THC as an alternative supplement are of concern, particularly in the combinations that include a drug that is a substrate of Cyp1a1, Cyp2b9, and Cyp3a11.

Miroestrol, a phytoestrogen from Pueraria mirifica, improves the antioxidation state in the livers and uteri of ß-naphthoflavone-treated mice.

Oxidative stress is involved in the progression of several diseases such as diabetes, hypertension, and age-related diseases. Miroestrol (MR) is a potent phytoestrogen from the tuberous root of Pueraria mirifica, a plant used in traditional Thai medicine that is claimed to have rejuvenating effects. In this study, the effects of MR on the antioxidation system, including anti-lipid peroxidation; on the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase; and on glutathione content in the livers and uteri of ß-naphthoflavone (BNF)-treated mice were determined. BNF-treated mice are a model of procarcinogen-exposed mice. The results showed that MR improved the antioxidant activities of SOD and CAT in the livers and uteri of both normal and BNF-treated mice, while estradiol (E2) increased SOD activity in the uteri of normal mice and CAT activity in the livers of both normal and BNF-treated mice. In the liver, MR increased the levels of several forms of glutathione, whereas in the uteri E2 and MR reduced the level of lipid peroxidation by decreasing the level of malondialdehyde. Therefore, the use of MR as an alternative hormone replacement therapy might be beneficial due to its ability to improve antioxidation systems.