Protective Effects of Gnetin C from Melinjo Seed Extract against High-Fat Diet-Induced Hepatic Steatosis and Liver Fibrosis in NAFLD Mice Model.

Nonalcoholic fatty liver disease (NAFLD), the most common form of chronic liver disease, can progress to hepatic steatosis, inflammation, and advanced fibrosis, increasing the risk of cirrhosis. Resveratrol, a natural polyphenol with antioxidant and anti-inflammatory properties, is beneficial in treating multiple metabolic diseases. Gnetin C, a resveratrol derivative obtained from Melinjo seed extract (MSE), shares similar health-promoting properties. We investigated the role of gnetin C in preventing NAFLD in a mouse model and compared it with resveratrol. Male C57BL/6J mice were fed a control diet (10% calories from fat), a high-fat choline-deficient (HFCD) diet (46% calories from fat) and HFCD diet supplemented with gnetin C (150 mg/kg BW·day-1) or resveratrol (150 mg/kg BW·day-1) for 12 weeks. Gnetin C supplementation reduced body and liver weight, and improved blood glucose levels and insulin sensitivity. Both gnetin C- and resveratrol reduced hepatic steatosis, with gnetin C also decreasing liver lipid content. Gnetin C and resveratrol ameliorated HFCD diet-induced hepatic fibrosis. The mRNA expression results, and western blot analyses showed that gnetin C and, to some extent, resveratrol downregulated fibrosis markers in the TGF-ß1 signaling pathway, indicating a possible safeguarding mechanism against NAFLD. These results suggest that gnetin C supplementation may protect against lipid deposition and hepatic fibrosis.

Rice Bran Supplementation Ameliorates Gut Dysbiosis and Muscle Atrophy in Ovariectomized Mice Fed with a High-Fat Diet.

Rice bran, a byproduct of rice milling, is rich in fiber and phytochemicals and confers several health benefits. However, its effects on gut microbiota and obesity-related muscle atrophy in postmenopausal status remain unclear. In this study, we investigated the effects of rice bran on gut microbiota, muscle synthesis, and breakdown pathways in estrogen-deficient ovariectomized (OVX) mice receiving a high-fat diet (HFD). ICR female mice were divided into five groups: sham, OVX mice receiving control diet (OC); OVX mice receiving HFD (OH); OVX mice receiving control diet and rice bran (OR); and OVX mice receiving HFD and rice bran (OHR). After twelve weeks, relative muscle mass and grip strength were high in rice bran diet groups. IL-6, TNF-α, MuRf-1, and atrogin-1 expression levels were lower, and Myog and GLUT4 were higher in the OHR group. Rice bran upregulated the expression of occludin and ZO-1 (gut tight junction proteins). The abundance of Akkermansiaceae in the cecum was relatively high in the OHR group. Our finding revealed that rice bran supplementation ameliorated gut barrier dysfunction and gut dysbiosis and also maintained muscle mass by downregulating the expression of MuRf-1 and atrogin-1 (muscle atrophy-related factors) in HFD-fed OVX mice.

The Prophylactic Effects of Glutamine on Muscle Protein Synthesis and Degradation in Rats with Ethanol-Induced Liver Damage.

The purpose of this research was to investigate the prophylactic effects of glutamine on muscle protein synthesis and degradation in rats with ethanol-induced liver injury. For the first 2 weeks, Wistar rats were divided into two groups and fed a control (n = 16) or glutamine-containing diet (n = 24). For the following 6 weeks, rats fed the control diet were further divided into two groups (n = 8 per group) according to whether their diet contained no ethanol (CC) or did contain ethanol (CE). Rats fed the glutamine-containing diet were also further divided into three groups (n = 8 per group), including a GG group (glutamine-containing diet without ethanol), GE group (control diet with ethanol), and GEG group (glutamine-containing diet with ethanol). After 6 weeks, results showed that hepatic fatty change, inflammation, altered liver function, and hyperammonemia had occurred in the CE group, but these were attenuated in the GE and GEG groups. Elevated intestinal permeability and a higher plasma endotoxin level were observed in the CE group, but both were lower in the GE and GEG groups. The level of a protein synthesis marker (p70S6K) was reduced in the CE group but was higher in both the GE and GEG groups. In conclusion, glutamine supplementation might elevate muscle protein synthesis by improving intestinal health and ameliorating liver damage in rats with chronic ethanol intake.

Fermented Rice Bran Supplementation Prevents the Development of Intestinal Fibrosis Due to DSS-Induced Inflammation in Mice.

Fermented rice bran (FRB) is known to protect mice intestines against dextran sodium sulfate (DSS)-induced inflammation; however, the restoration of post-colitis intestinal homeostasis using FRB supplementation is currently undocumented. In this study, we observed the effects of dietary FRB supplementation on intestinal restoration and the development of fibrosis after DSS-induced colitis. DSS (1.5%) was introduced in the drinking water of mice for 5 days. Eight mice were sacrificed immediately after the DSS treatment ended. The remaining mice were divided into three groups, comprising the following diets: control, 10% rice bran (RB), and 10% FRB-supplemented. Diet treatment was continued for 2 weeks, after which half the population of mice from each group was sacrificed. The experiment was continued for another 3 weeks before the remaining mice were sacrificed. FRB supplementation could reduce the general observation of colitis and production of intestinal pro-inflammatory cytokines. FRB also increased intestinal mRNA levels of anti-inflammatory cytokine, tight junction, and anti-microbial proteins. Furthermore, FRB supplementation suppressed markers of intestinal fibrosis. This effect might have been achieved via the canonical Smad2/3 activation and the non-canonical pathway of Tgf-ß activity. These results suggest that FRB may be an alternative therapeutic agent against inflammation-induced intestinal fibrosis.

Complementary effects of pine bark extract supplementation on inattention, impulsivity, and antioxidative status in children with attention-deficit hyperactivity disorder: A double-blinded randomized placebo-controlled cross-over study.

The purpose of this study was to investigate the complementary effects of polyphenolic compounds from pine bark extract (PE) as a strong antioxidative substrate on the symptoms of inattention and impulsivity in children with attention-deficit hyperactivity disorder (ADHD). This was a randomized, double-blind, crossover, placebo-controlled study that included two experimental units (4 weeks with PE supplementation and 4 weeks with placebo supplementation) separated by a 2-week washout period. ADHD participants were supplemented with 25 mg or 50 mg PE. We recruited 20 participants (17 boys and 3 girls) with a mean age of 10.0 ± 2.1 years. PE supplementation caused a significant reduction in the inattention and hyperactivity-impulsivity items of SNAP-IV. During the period of PE supplementation, the item of commissions in the Continuous Performance Test III (CPT III) significantly decreased, which was used to evaluate the symptoms of inattention and impulsivity. In addition, the erythrocytic reduced glutathione/oxidized glutathione ratio significantly increased, and the plasma TBARs level significantly decreased after 4 weeks of PE supplementation. However, there was no significant correlation between CPT III (commission) and antioxidative status indictors. PE supplementation may have potential effects of ameliorating inattention and impulsivity, and elevating the antioxidative status in children with ADHD.

Effects of Coriandrum sativum Seed Extract on Aging-Induced Memory Impairment in Samp8 Mice.

The purpose of this study was to investigate whether or not Coriandrum sativum seed extract (CSSE) can ameliorate memory impairment in senescence-accelerated mouse-prone 8 (SAMP8) mice. Sixteen 10-week-old male SAMP8 mice were divided into two groups, which were orally administrated water (SAMP8(-)) or CSSE (200 mg/kg/day; SAMP8(+)). Eight 10-week-old male Institute of Cancer Research (ICR) mice were used as a normal control group and were also orally administrated water. The mean escape time in the Barnes maze test of SAMP8(-) mice was significantly longer than that of ICR mice. However, SAMP8(+) mice showed a shorter mean escape time compared to that of SAMP8(-) mice. Neurofilament messenger (m)RNA levels significantly decreased in the frontal lobe of SAMP8(-) mice when compared with ICR mice, but significantly increased in SAMP8(+) mice relative to SAMP8(-) mice. In addition, mRNA levels of inducible nitric oxide synthase (iNOS) and neuronal (n)NOS significantly increased in the frontal lobe of SAMP8(-) mice, but only the mRNA level of nNOS significantly decreased in SAMP8(+) mice. These results indicated that continuous oral administration of CSSE for 12 weeks could ameliorate aging-induced memory declines in the senescence-accelerated SAMP8 mouse model.

Fish oil up-regulates hepatic autophagy in rats with chronic ethanol consumption.

In this study, we examined the regulation of autophagy by fish oil in rats under ethanol-containing diets. Thirty male Wistar rats (8-week-old) were divided into six groups and fed a control diet or an ethanol-containing diet, which was adjusted with fish oil to replace 25% or 57% of the olive oil. After 8 weeks, rats in the E (ethanol diet) group showed the significantly higher plasma aspartate transaminase (AST) and alanine transaminase (ALT) activities, protein expression of cytochrome P450 2E1 (CYP2E1), and levels of hepatic inflammatory cytokines. However, all of those items had significantly decreased in the EF25 (ethanol with 25% fish oil) and EF57 (ethanol with 57% fish oil) groups. As to autophagic indicators, protein expressions of mammalian target of rapamycin (mTOR), Unc-51-like autophagy activating kinase 1 (ULK1) and p62 were significantly increased in the E group. Conversely, the protein expressions of light chain 3II (LC3II)/LC3I and Beclin1 were significantly decreased in the E group. On the other hand, protein expressions of phosphorylated Akt, mTOR, ULK1, and p62 were down-regulated, protein expressions of LC3II/LC3I and Beclin1 were conversely up-regulated in the EF25 and EF57 groups. Fish oil activated hepatic autophagy via inhibiting the Akt signaling pathway, which exerted protective effects against ethanol-induced liver injury in rats.

Rice Bran Reduces Weight Gain and Modulates Lipid Metabolism in Rats with High-Energy-Diet-Induced Obesity.

Obesity has become an epidemic worldwide. It is a complex metabolic disorder associated with many serious complications and high morbidity. Rice bran is a nutrient-dense by product of the rice milling process. Asia has the world's highest rice production (90% of the world's rice production); therefore, rice bran is inexpensive in Asian countries. Moreover, the high nutritional value of the rice bran suggests its potential as a food supplement promoting health improvements, such as enhancing brain function, lowering blood pressure, and regulating pancreatic secretion. The present study evaluated the anti-obesity effect of rice bran in rats with high-energy diet (HED)-induced obesity. Male Sprague-Dawley rats were randomly divided into one of five diet groups (n = 10 per group) and fed the following for eight weeks: Normal diet with vehicle treatment, HED with vehicle, rice bran-0.5X (RB-0.5X) (2% wt/wt rice bran), RB-1.0X (4% wt/wt rice bran), and RB-2.0X (8% wt/wt rice bran). Rice bran (RB-1.0X and RB-2.0X groups) markedly reduced obesity, including body weight and adipocyte size. In addition, treating rats with HED-induced obesity using rice bran significantly reduced the serum uric acid and glucose as well as the liver triglyceride (TG) and total cholesterol (TC). Furthermore, administration of an HED to obese rats significantly affected hepatic lipid homeostasis by increasing phosphotidylcholine (PC; 18:2/22:6), diacylglycerol (DG; 18:2/16:0), DG (18:2/18:1), DG (18:1/16:0), cholesteryl ester (CE; 20:5), CE (28:2), TG (18:0/16:0/18:3), and glycerol-1-2-hexadecanoate 3-octadecanoate. However, the rice bran treatment demonstrated an anti-adiposity effect by partially reducing the HED-induced DG (18:2/18:1) and TG (18:0/16:0/18:3) increases in obese rats. In conclusion, rice bran could act as an anti-obesity supplement in rats, as demonstrated by partially reducing the HED-induced DG and TG increases in obese rats, and thus limit the metabolic diseases associated with obesity and the accumulation of body fat and hepatic lipids in rats.

High Fat Diet with a High Monounsaturated Fatty Acid and Polyunsaturated/Saturated Fatty Acid Ratio Suppresses Body Fat Accumulation and Weight Gain in Obese Hamsters.

The aim of this study was to investigate the effect of a high fat diet with experimental oil consisting of 60% MUFAs (monounsaturated fatty acids) with a P/S ratio of 5 on fat deposition and lipid metabolism in obese hamsters. Hamsters were randomly assigned to a control group and a diet-induced obesity group for nine weeks. Then an additional eight-week experimental period began, during which obese hamsters were randomly divided into three groups and fed different amounts of the experimental oil mixture in their diets as follows: 5%, 15%, and 20% w/w (OB-M5, OB-M15, and OB-M20 groups, respectively). The results showed that the OB-M15 and OB-M20 groups had significantly lower blood cholesterol and higher insulin levels. Compared to the control group, the three obese groups exhibited higher hepatic fatty acid synthase activity; however, the acyl-CoA oxidase activities were also enhanced. Although dietary fat content differed, there were no differences in energy intake, final body weights, and epididymal fat weights among the four groups. These results suggest that regardless of whether the specimens had a high fat intake or not, dietary fat containing high MUFAs with a high P/S ratio had beneficial effects on maintaining blood lipid profiles and may not result in body fat accumulation in obese hamsters, possibly by promoting lipolytic enzyme activities.

Angelica Sinensis promotes myotube hypertrophy through the PI3K/Akt/mTOR pathway.

BACKGROUND: Angelica Sinensis (AS), a folk medicine, has long been used in ergogenic aids for athletes, but there is little scientific evidence supporting its effects. We investigated whether AS induces hypertrophy in myotubes through the phosphatidylinositol 3-kinase (PI3K)/Akt (also termed PKB)/mammalian target of the rapamycin (mTOR) pathway. METHODS: An in vitro experiment investigating the induction of hypertrophy in myotubes was conducted. To investigate whether AS promoted the hypertrophy of myotubes, an established in vitro model of myotube hypertrophy with and without AS was used and examined using microscopic images. The role of the PI3K/Akt/mTOR signaling pathway in AS-induced myotube hypertrophy was evaluated. Two inhibitors, wortmannin (an inhibitor of PI3K) and rapamycin (an inhibitor of mTOR), were used. RESULT: The results revealed that the myotube diameters in the AS-treated group were significantly larger than those in the untreated control group (P < 0.05). Wortmannin and rapamycin inhibited AS-induced hypertrophy. Furthermore, AS increased Akt and mTOR phosphorylation through the PI3K pathway and induced myotube hypertrophy. CONCLUSION: The results confirmed that AS induces hypertrophy in myotubes through the PI3K/Akt/mTOR pathway.

Ganoderma tsugae hepatoprotection against exhaustive exercise-induced liver injury in rats.

Several studies have been shown that accelerated apoptosis is involved in post-exercise lymphocytopenia and tissue damage after high-intensity exercise. Ganoderma tsugae (GT) is one of the well-known medicinal mushrooms that possess various pharmacological functions. This mushroom has traditionally been used for health promotion purposes. This study investigates the hepatoprotective effects of GT on exhaustive exercise-induced liver damage. Twenty-four male Sprague-Dawley rats were randomly divided into four groups and designated as exhaustive exercise only (E), exhaustive exercise with low dosage (EL), medium dosage (EM) and high dosage (EH) GT at 0, 0.1875, 0.9375 and 1.875 g/kg/day, respectively. After 30 days all rats were euthanized immediately after an exhaustive running challenge on a motorized treadmill. The rat livers were immediately harvested. Evidence of apoptotic liver cell death was revealed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and caspases mediated cascade events. DNA fragmentation, an apoptosis process, can be examined using TUNEL assay. A few TUNEL-positive hepatocytes, compared to the exercise only group, were observed in the livers from exhaustive animals supplemented with GT. Immunoblot analysis also showed that caspase-6-mediated specific cleavage of lamin A/C was increased significantly in the livers of group E, but was significantly decreased in the EM and EH groups. Our observations demonstrate that GT possesses anti-apoptotic and hepatoprotective potential after exhaustive exercise.

The antiapoptotic effects of different doses of ß-carotene in chronic ethanol-fed rats.

BACKGROUND: Ethanol consumption might induce hepatic apoptosis and cause liver damage. The study was to investigate the effects of different doses of ß-carotene supplementation on the antioxidant capacity and hepatic apoptosis in chronic ethanol-fed rats. METHODS: Rats were divided into 6 groups: C (control liquid diet), CLB [control liquid diet with ß-carotene supplementation at 0.52 mg/kg body weight (BW)/day], CHB (control liquid diet with ß-carotene supplementation at 2.6 mg/kg BW/day), E (ethanol liquid diet), ELB (ethanol liquid diet with ß-carotene supplementation at 0.52 mg/kg BW/day), and EHB (ethanol liquid diet with ß-carotene supplementation at 2.6 mg/kg BW/day). After 12 weeks, rats were sacrificed and blood and liver samples were collected for analysis. RESULTS: Lipid peroxidation and hepatic cytochrome P450 2E1 (CYP2E1) expression had increased, and hepatic Fas ligand, caspase-8, cytochrome c, caspase-9, and -3 expressions had significantly increased in the E group. However, lipid peroxidation and CYP2E1, caspase-9, and -3 expressions were significantly lower and Bcl-xL expression was higher in the ELB group. The hepatic tumor necrosis factor (TNF)-α level, lipid peroxidation, and cytochrome c expression were significantly lower and Bcl-2 expression was significantly higher in the EHB group. CONCLUSIONS: The results suggest that ethanol treatment causes oxidative stress and hepatic apoptosis leading to liver injury, and ß-carotene supplementation (0.52 mg/kg BW/day) can prevent ethanol-induced liver damage by decreasing ethanol-induced oxidative stress and inhibiting apoptosis in the liver.

The Hypouricemic Effect of Balanophora laxiflora Extracts and Derived Phytochemicals in Hyperuricemic Mice.

The objective of this study is to evaluate the lowering of uric acid using Balanophora laxiflora extracts and derived phytochemicals on potassium-oxonate-(PO-) induced hyperuricemia in mice. The results revealed that ethyl acetate (EtOAc) fraction of B. laxiflora extracts exhibited strong xanthine-oxidase-(XOD-) inhibitory activity. In addition, among the 10 subfractions (EA1-10) derived from EtOAc fraction, subfraction 8 (EA8) exhibited the best XOD-inhibitory activity. Four specific phytochemicals, 1-O-(E)-caffeoyl-ß-D-glucopyranose (1), 1-O-(E)-p-coumaroyl-ß-D-glucopyranose (2), 1,3-di-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-ß-D-glucopyranose (3), and 1-O-(E)-caffeoyl-4,6-(S)-hexahydroxydiphenoyl-ß-D-glucopyranose (4), were further isolated and identified from this subfraction. Compounds 3 and 4 exhibited the strongest XOD-inhibitory activity compared with other compounds, and both hydrolyzable tannins were determined to be noncompetitive inhibitors according to the Lineweaver-Burk plot. On the other hand, the in vivo hypouricemic effect in hyperuricemic mice was consistent with XOD-inhibitory activity, indicating that B. laxiflora extracts and derived phytochemicals could be potential candidates as new hypouricemic agents.

Beneficial effects of catechin-rich green tea and inulin on the body composition of overweight adults.

Green tea catechin has been proposed to have an anti-obesity effect. The aim of the present study was to investigate whether the effect of catechin-rich green tea in combination with inulin affects body weight and fat mass in obese and overweight adults. A total of thirty subjects were divided into a control group and an experimental group who received 650 ml tea or catechin-rich green tea plus inulin. A reduction of body weight ( - 1·29 (sem 0·35) kg) and fat mass (0·82 (sem 0·27) kg) in the experimental group was found after 6 weeks, and no adverse effects were observed. After refraining from consumption for 2 weeks, sustained effects on body weight and fat mass were observed. We conclude that continuous intake of catechin-rich green tea in combination with inulin for at least 3 weeks may be beneficial for weight management.

Folate and vitamin B12 improved alcohol-induced hyperhomocysteinemia in rats.

OBJECTIVE: The purpose of this study was to investigate the protective effects of combined treatment of folate and vitamin B12 against alcoholic liver disease. METHODS: Male Wistar rats weighing about 160 g were divided into four groups: an ethanol group fed an ethanol liquid diet; a control group pair-fed an isoenergetic diet without ethanol; an ethanol and vitamin group fed an ethanol-containing diet that was supplemented with folate (10 mg/kg of body weight per day) and vitamin B12 (0.5 mg/kg of body weight per day); and a control and vitamin group fed an isoenergetic diet without ethanol, which was supplemented with folate (10 mg/kg of body weight per day) and vitamin B12 (0.5 mg/kg of body weight per day). RESULTS: After 16 wk, the plasma folate concentration in the ethanol group was significantly lower than in the other three groups. The plasma homocysteine concentration in the ethanol group was significantly higher than in the other three groups. The hepatic matrix metalloproteinase-2 concentration in the ethanol group was significantly higher than in the control and ethanol/vitamin groups. Furthermore, the plasma homocysteine concentration at the 16th week and the hepatic matrix metalloproteinase-2 concentration showed a significant positive correlation in rats of each group. In addition, pathologic evidence of liver fibrosis was observed only in the ethanol group. Furthermore, hepatic cytochrome 2E1 protein expression in group E increased significantly. CONCLUSION: These results suggest that combined treatment of folate and vitamin B12 can alleviate alcoholic liver injury that may be related to normalization of plasma homocysteine levels.

Effects of glutamine administration on inflammatory responses in chronic ethanol-fed rats.

The purpose of this study was to investigate the effects of glutamine supplementation on inflammatory responses in chronic ethanol-fed rats. Male Wistar rats weighing about 160 g were divided into five groups. Two groups were fed a normal liquid diet and three groups were fed a glutamine-containing liquid diet. After 1 week, one of the normal liquid diet groups was fed an ethanol-containing liquid diet (CE), and the other group served as the control (CC) group. At the same time, one of the glutamine-containing liquid diet groups was continually fed the same diet (GCG), but the other two groups were fed ethanol-containing diet supplemented with glutamine (GEG) or without glutamine (GE). The following items were analyzed: (1) liver function, (2) cytokine contents, and (3) hepatic oxidative stress. The activities of aspartate transaminase (AST) and alanine transaminase (ALT) and levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß in the CE group had significantly increased. In addition, hepatic cytochrome P450 2E1 (CYP2E1) expression had significantly increased in the CE, GE and GEG groups. However, the activities of AST and ALT and levels of TNF-α and IL-1ß in the GE group were significantly lower than those of the CE group. The results suggest that the plasma inflammatory responses of rats fed an ethanol-containing liquid diet for 7 weeks significantly increased. However, pretreatment with glutamine improved the plasma inflammatory responses induced by ethanol.

Phytochemicals from Acacia confusa heartwood extracts reduce serum uric acid levels in oxonate-induced mice: their potential use as xanthine oxidase inhibitors.

In this study, the antihyperuricemic effect of Acacia confusa heartwood extracts and their phytochemicals on potassium oxonate (PO)-induced acute hyperuricemia was investigated for the first time. All treatments at the same dosage (100 mmol/kg) were administered to the abdominal cavity of PO-induced hyperuricemic mice, and serum uric acid level was measured at 3 h after administration. In experimental mice, serum uric acid level was significantly suppressed by the administration of A. confusa heartwood extracts and their major phytochemicals, (-)-2,3-cis-3,4-cis-3,3',4,4',7,8-hexahydroxyflavan, (-)-2,3-cis-3,4-cis-4'-methoxy-3,3',4,7,8-pentahydroxyflavan, melanoxetin, transilitin, and okanin, relative to the PO group. The direct inhibitory effect of these five compounds on xanthine oxidase (XOD) activity was examined using isothermal titration calorimetry (ITC). Among them, melanoxetin showed a more remarkable inhibitory effect on XOD activity than allopurinol, a clinical drug used for XOD inhibitor. To further understand the stereochemistry between XOD and melanoxetin (or allopurinol), structure-based molecular modeling was performed. Melanoxetin undergoes extended interactions in the hydrophobic region via the 3',4'-dihydroxyphenyl moiety, thus accounting for its higher binding affinity to XOD than allopurinol. These results indicate that A. confusa heartwood extracts and their major phytochemicals exhibit strong XOD inhibitory effects, which reduce serum uric acid levels while inhibiting uric acid generation in purine metabolism.

beta-Carotene exhibits antioxidant and anti-apoptotic properties to prevent ethanol-induced cytotoxicity in isolated rat hepatocytes.

The study was designed to evaluate the effects of 1 microM beta-carotene on antioxidant status in ethanol-treated rat hepatocytes and investigate possible anti-apoptotic mechanisms of beta-carotene in protecting ethanol-induced cytotoxicity. The isolated rat hepatocytes were incubated for 48 h in a medium with or without alcohol (100 mM) and mu-carotene (1 microM) using the following groups: the control (C), beta-carotene (CB), ethanol (E), and ethanol + beta-carotene (EB) groups. The cell viability, antioxidative status, cytochrome P450 2E1 (CYP2E1) and caspase expressions in hepatocytes were measured. The E group demonstrated lower cell viability, glutathione (GSH) levels, and lipid peroxide accumulation in rat hepatocytes; meanwhile, CYP2E1, caspase-3, and caspase-9 expressions increased. In contrast, cell viability, GSH levels, and glutathione reductase (GRD) activity significantly increased while lipid peroxides and expressions of CYP2E1, casapse-3, and caspase-9 decreased in the EB group. The results suggest that ethanol treatment decreases cell viability in rat hepatocytes via induced oxidative stress. 1 muM beta-carotene decreased oxidative stress and prevented ethanol-induced cell death by inhibiting caspase-9 and caspase-3 expression.

Effects of beta-carotene on antioxidant status in rats with chronic alcohol consumption.

This study examined the effects of beta-carotene on antioxidant status in rats with chronic alcohol consumption. At the beginning of experiment (week 0), according to both the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, rats (n = 24) were divided into 3 groups and fed with a standard diet (group C), a diet containing ethanol (group E), or a diet containing ethanol and beta-carotene (group E+B). After 10 weeks, plasma AST and ALT, fat accumulation in the liver, antioxidant enzyme activities in erythrocytes and the liver, malondialdehyde (MDA), and alpha-tocopherol and retinol in plasma and hepatic samples were analyzed. The chronic alcohol diet significantly increased AST and ALT levels in plasma, and these changes were prevented by supplementing the diet with beta-carotene. Glutathione (GSH) in erythrocytes and in the liver was significantly elevated in rats fed with a diet containing beta-carotene. The results indicate that beta-carotene supplementation can prevent ethanol-induced liver damage and increase GSH concentrations in erythrocytes and the liver.

Protective effect of Acacia confusa bark extract and its active compound gallic acid against carbon tetrachloride-induced chronic liver injury in rats.

Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been traditionally used as a medicine. The hepatoprotective effects of A. confusa bark extract (ACBE) and its active constituent gallic acid were evaluated against carbon tetrachloride (CCl(4))-induced hepatotoxicity in rats. CCl(4)-induced hepatic pathological damage and significantly increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and malondialdehyde (MDA) in plasma, and cytochrome P4502E1 (CYP2E1) protein expression in hepatic samples, and decreased the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) in erythrocytes. Treatment with ACBE, gallic acid or silymarin could decrease significantly the AST, ALT, and MDA levels in plasma, and CYP2E1 expression in liver tissues, and increase the activities of SOD and GPX in erythrocyte when compared with CCl(4)-treated group. Liver histopathology also showed that ACBE, gallic acid or silymarin could significantly reduce the incidence of liver lesions induced by CCl(4). These results suggested that the ACBE and gallic acid exhibit potent hepatoprotection against CCl(4)-induced liver damages in rats, and the hepatoprotective effects of ACBE and gallic acid may be due to the modulation of antioxidant enzymes activities and inhibition of lipid peroxidation and CYP2E1 activation.