Hepatoprotective effects of Rubus coreanus miquel concentrates on liver injuries induced by carbon tetrachloride in rats

As well-being foods pursuing healthy life are becoming popular, interest in Rubus coreanus Miquel (RCM) fruit, a type of Korean blackberry, is increasing due to its medicinal actions including protecting the liver, brightening the eyes, and alleviating diabetes. This study was carried out to evaluate the hepatoprotective effects of RCM concentrates on liver injuries induced by carbon tetrachloride (CCl4) in rats. RCM, produced in June ~ July 2008 at Chunbook, Gochang (South Korea), was finely mashed. The seeds were removed and the juices were condensed. Thirty-two Sprague-Dawley rats were divided into four groups according to treatment: normal (eight rats), CCl4, 1% RCM, and 2% RCM. Experimental diets were provided to the experimental animals for 4 weeks. We measure total cholesterol, high density lipoprotein-cholesterol (HDL-C), aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) levels. Part of the livers was isolated for histopathological evaluation, and analyzed for lipid peroxide (TBARS), superoxide dismutase (SOD) and liver proteins. The activities of serum AST, ALT, and ALP were elevated following CCl4 administration. Levels of hepatic TBARS were also significantly increased in the CCl4 groups. However, hepatic TBARS levels and the activities of serum enzymes were markedly reduced by supplementation with the RCM concentrates (P < 0.05). Hepatic SOD activity increased in the RCM concentrates group versus CCl4 groups. Histopathological examination revealed massive necrosis in the centrilobular area and degenerative changes caused by CCl4 were ameliorated by dietary supplementation with RCM concentrates. These results suggest that RCM concentrates have hepatoprotective effects and may improve the symptoms of liver injuries.

Effect of Vitamin E Supplementation on Lipid Peroxide Levels of Blood and Liver in Zinc Deficient Rats

To study antioxidant role of zinc, the effects of dietary zinc deficiency and vitamin E supplementation on lipid peroxidation were studied. Levels of zinc and vitamin E in blood and liver were also measured. Forty Sprague-Dawley male rats aging 8 weeks old were used as experimental animals. Zinc deficient diet (Zn, 0 ppm), zinc normal diet (Zn, 36.5 ppm), and vitamin E supplemented diet (1,000 IU alpha-tocopherol/kg of diet) were used as experimental diet. During the first three weeks, rats were divided into zinc normal (ZnN, 8 animals) and zinc deficient (ZnD, 32 animals) group. Eight rats from each group were sacrificed to get blood and liver after 3 weeks of experiment. The remaining 24 zinc deficient rat were then divided into zinc normal (ZnDN), zinc deficient (ZnDD), vitamin E supplemented (ZnDE) diet groups. After another 3 weeks of experiment, all animals were sacrificed as well. Thiobarbituric acid reactive substance (TBARS) levels in plasma and liver, conjugated diene levels in liver were measured as lipid peroxidation index. There were no significant differences in food intake, body weight gain, and food efficiency ratio among groups. Weights of liver per 100 g body weight were not significantly different. There were no significant differences in Zn levels in serum. Plasma and liver TBARS level, and liver conjugated diene level were significantly lower in ZnDE than in ZnDN or ZnDD, and significantly higher in ZnDD than in ZnDN. Therefore, it seems that lipid peroxidation is accelerated by dietary zinc deficiency and recovered partly by vitamin E supplementation.

Effects of Dietary Calcium Level and Hijikia fusiforme Supplementation on Bone Indices and Serum Lipid Levels in Ovariectomized Rats

This study explored the effects of dietary calcium level and Hijikia fusiforme supplementation on bone indices and serum lipid levels using 36 female Sprague-Dawley rats as a model. Rats received low Ca diet for 3 weeks after ovariectomy. The rats were then divided into six dietary groups and fed low (0.1% Ca), normal (0.5% Ca) and high (1.5% Ca) Ca diets (CaL, CaN, CaH) and low, normal, high Ca diets with Hijikia fusiforme supplementation (CaLH, CaNH, CaHH) for 3 weeks. After each experimental periods, 24 hour urine and/or blood samples, left and right femurs were collected for analysis. Serum Ca concentration showed no significant difference by dietary Ca levels and Hijikia fusiforme supplementation. Alkaline phosphatase activity was significantly higher in normal and high Ca group compared to low Ca group. Serum total cholesterol, triglyceride and total lipid were not significantly different among groups. HDL-cholesterol showed no significant difference by Hijikia fusiforme supplementation. However, the normal and high Ca groups showed significantly higher HDL-cholesterol compared to the low Ca group. Urinary hydroxyproline and hydroxyproline/creatinine ratio were not significantly different among groups. The wet weight of the femur was significantly higher in low Ca group compared to normal or high Ca group. The dry weight, wet weight/body weight, length and breaking force of the femur were not significantly different among groups. Ash contents/wet weight of the femur was significantly increased as dietary Ca levels up and significantly higher in Hijikia fusiforme supplementation groups. The Ca content of the femur were significantly higher in the normal and high Ca groups than the low Ca group. However, there was no significant difference in Ca content by Hijikia fusiforme supplementation.

Effects of Chongkukjang Intake on Lipid Metabolism and Liver Function in Ethanol Consumed Rats

This study was performed to investigate the effect of chongkukjang intake on lipid metabolism and liver function in ethanol consumed rats. Twenty one Sprague-Dawley male rats aging 4 weeks old were used as experimental animals, which were divided into three dietary groups: casein diet (CA), soybean diet (SB) and chongkukjang diet (CJ). Alcohol was consumed with water as 25% (v/v) ethanol solution. After 4 weeks of experimental period, rats were sacrificed to get blood and liver samples for analysis of lipids, lipid peroxides, antioxidative enzymes and biochemical indices of liver function. The mean body weight, food intake and liver index were not significantly different among three groups. Serum level of total lipid, triglyceride and total cholesterol of chongkukjang diet group was the lowest among three groups although the difference was not significant. HDL-cholesterol level was significantly (p < 0.05) higher in chongkukjang diet group than that of casein diet group. LDL-cholesterol level of chongkukjang and soybean diet group was significantly (p < 0.05) lower than that of casein diet group respectively. Liver TBARS of chongkukjang and soybean diet group was significantly (p < 0.05) lower than that of casein diet group respectively. The superoxide dismutase activity of chongkukjang diet group was significantly (p < 0.05) higher than that of casein diet group. Catalase activity was not significantly different among three groups. As indices of liver function, glutamic oxaloacetic transminase (GOT), glutamic pyruvic transminase (GPT), gamma-glutamyl transpeptidase (gamma-GTP) and lactate dehydrogenase (LDH) were not significantly different among three groups. Serum alcohol concentration and activities of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) were not significantly different among three groups. The chongkukjang diet seems to give a beneficial effect for improving lipid metabolism by increasing HDLcholesterol level and SOD activity while reducing liver TBARS level. However, effect on liver function has to be investigated further.

Effects of beta-Carotene Supplementation on Lipid Peroxide Levels and Antioxidative Enzyme Activities in Alcoholic Fatty Liver Rats

This study was performed to investigate the effect of dietary beta-carotene supplementation on lipid peroxide levels and antioxidant enzyme activities in alcoholic fatty liver rats. Forty five Sprague-Dawley male rats aging 8 weeks were used as experimental animals, which were divided into the control diet (CD) and the ethanol diet (ED) and the ethanol + 0.02% beta-carotene diet (EbetaD) groups and fed the experimental diet respectively for 5 weeks. After the feeding, rats were sacrificed to get blood and liver to analyze lipid and lipid peroxide levels and antioxidant enzyme activities. The mean body weight and food intake of the ethanol diet group was significantly lower than that of the control diet. The liver index (LI) of the ethanol diet group was significantly higher than those of the control diet and the beta-carotene supplementation group. Serum levels of total lipid, triglyceride of the ethanol diet group were significantly higher than those of the control diet and the beta-carotene supplementation group. Total cholesterol levels were not significantly different among all groups. HDL-cholesterol of the ethanol diet group was significantly lower than those of the control diet and the beta-carotene supplementation group. Liver TBARS of the ethanol diet group was significantly higher than those of the control diet and the beta-carotene supplementation group. Liver lipofuscin and conjugated diene levels were not significantly different among all groups. The superoxide dismutase activity of the ethanol diet group was significantly lower than those of the control diet and the beta-carotene supplementation group. Catalase and glutathione peroxidase activities were not significantly different among all groups. Because beta-carotene supplementation significantly decrease the serum total lipid, triglyceride, liver TBARS levels and increase the superoxide dismutase activity in alcoholic fatty liver rats, beta-carotene supplementation seems to give beneficial effect for the alcoholics.

Effect of Smoking and Carotenoid-rich Food Consumption on Lipid Peroxidation and Antioxidant Status

This study was performed to determine the effect of carotenoid-rich food consumption and smoking on the lipid peroxidation and antioxidant status in human. The subjects consisted of the health 210 middle-aged adults who visited health care center in the Inha University hospital. The blood and urine samples of the subjects were taken to analyze serum lipid profiles, plasma TBARS, total antioxidant status (TAS) and urinary 8-isoprostanes concentration. The anthropometric indices of the subjects were measured. The nutritional intake and the frequency of carotenoid-rich food consumption was determined by semi-quantitative food frequency questionnaire survey. HDL-cholesterol level of the smoking subjects was significantly lower than that of the non-smoking subjects in men. In the analysis of the carotenoid-rich food consumption, the frequency of pepper and tomato consumption of the non-smoking subjects was significantly higher than that of the smoking subjects in men. In women, the Sequency of pear and peach consumption of the non-smoking subjects was significantly higher than that of the smoking subjects. HDL-cholesterol level of the high carotenoid rich food consumption group was significantly higher than that of medium and low group in women. TAS of the high carotenoid rich food consumption group was significantly higher than that of medium and low group. In conclusion, carotenoid intakes seemed to be effective to reduce lipid peroxidation and increase antioxidant status in the body. The frequency of the carotenoid-rich food consumption seemed to be lower in the smokers than in the non-smokers. However, further researches consisted of large-scaled and randomized clinical trials are required to determine whether carotenoids have any other beneficial effect in human.

Effect of beta-carotene Supplementation on Lipid Peroxides and Antioxidative Enzyme Activities in Hyperlipidemic Rats

This study was performed to investigate the effect of dietary beta-carotene supplementation on lipid metabolism and antioxidant enzyme activities in hyperlipidemic rats. Fifty Sprague-Dawley male rats aging 7 weeks were fed the control diet (CD, 5% corn oil) and the high fat diet (HFD, 15% beef tallow + 1% cholesterol) for 4 weeks and then 0.02% beta-carotene was supplemented to CD and HFD group for 8 more weeks. Serum lipid compositions, lipid peroxides and antioxidative enzymes in liver were analyzed at 4, 8 and 12week of the experiment. Serum levels of total lipid, total cholesterol, triglyceride, LDL-cholesterol, VLDL-cholesterol were higher in HFD groups than in CD groups (p < 0.001). Serum levels of HDL-cholesterol were higher in CD groups than in HFD groups (p < 0.01). The effect of beta-carotene supplementation was not significant in all groups but tended to be lower in total lipid, total cholesterol and triglyceride. Thiobarbituric acid reactive substances (TBARS) levels in plasma and liver were showed significantly higher in HFD groups (p < 0.001, p < 0.05). The effects of beta-carotene supplementation on the level of plasma and liver TBARS were not found except HFD groups at 12 week. Liver conjugated diene levels in HFD groups were higher than in CD groups (p < 0.01), but the effect of beta-carotene supplementation did not show any differences. Liver lipofuscin levels were not significantly different among all groups. The activities of superoxide dismutase (SOD) and catalase were significantly lower in HFD groups at 8 week (p < 0.001) but were not significantly different at 4 and 12week. The activity of SOD in beta-carotene supplemented HFD group was significantly higher at 8 week (p < 0.01). Glutathione peroxidase (GSHPx) activity was significantly lower in HFD groups (p < 0.01) and was significantly increased in groups supplemented beta-carotene (p < 0.05). It is suggested that beta-carotene supplementation partly decreases the serum lipid and lipid peroxide levels and increases the activities of antioxidant enzymes in hyperlipidemic rats.

Effects of beta-Carotene Supplementation on Lipid Peroxide Levels and Antioxidative Enzyme Activities in Diabetic Rats

This study investigated the effect of dietary beta-carotene supplementation on lipid peroxidation and anti oxidative enzyme activity as indices of oxidative stress in diabetic rats. Fifty Sprague-Dawley male rats aging 7 weeks were used as experimental animals, which were divided into the non-diabetic control group and the diabetic group. The diabetic group received an intraperitoneal injection with streptozotocin to induce diabetes. Then the diabetic rats were divided into four dietary groups which contained different amounts of beta-carotene; 0%, 0.002%, 0.02%, or 0.2% of the diet. The diabetic rats were fed the experimental diets and the non-diabetic rats were fed the basal diet without beta-carotene supplementation for 2 weeks and then sacrificed. The diabetic group had a significantly higher blood glucose level than the non-diabetic group. However, blood glucose level were not significantly changed by the level of dietary beta-carotene supplementation. Compared to the non-diabetic control group, the diabetic control group indicated a significant increase of plasma thiobarbituric acid reactive substance (TBARS). Liver TBARS level also tended to be higher in diabetic control group, although it was not significant. The beta-carotene supplementation did not reduce plasma TBARS level. However, Liver TBARS level was significantly decreased when 0.02% or more beta-carotene was supplemented in the diet. The liver lipofuscin level in the diabetic control group was higher than in the non-diabetic control group, but the effect of beta-carotene supplementation did not show any differences. Superoxide dismutase activity was significantly lower in the diabetic group, but it was increased in groups receiving 0.02% or more beta-carotene. Compared to the non-diabetic control group, lower activities of catalase and glutathione peroxidase were observed in the diabetic control group, although it was not significant. Catalase and glutathione peroxidase activities tended to increase as the levels of beta-carotene supplementation increased, although it was not statistically significant. Therefore, it seems that dietary beta-carotene supplementation might reduce diabetic complications by partly decreasing the lipid peroxidation and increasing the activity of antioxidative enzyme in diabetes.