Use of olive oil based emulsions as an alternative to soybean oil based emulsions in total parenteral nutrition and their effects on liver regeneration following hepatic resection in rats

Background/Aim: The main objective of this study was to compare the effects of olive oil to those of soybean oil on liver tissue regeneration following hepatic resection in rats. Methods: Seventy albino Wistar rats were randomly assigned to seven groups which contained 10 rats each. Group 1 was the sham-treated group; groups 2 and 3 received total parenteral nutrition (TPN) containing soybean oil lipid emulsions (20% Lipofundin MCT/LCT) for 48 or 72 h; groups 4 and 5 received TPN containing olive oil (80%)/soybean oil (20%) lipid emulsions (Clin-Oleic 20%) for 48 or 72 h; group 6 was the control group for 48 h, and group 7 was the control group for 72 h. TPN was given via internal jugular vein, and 70% hepatic resection was performed in the study groups. In addition, hepatic resections with no TPN were performed in the control groups, except the sham group. Relative liver weight, mitotic index, proliferating cell nuclear antigen labeling index, and carnitine levels in liver tissue samples were used to assess hepatic regeneration. Thiobarbituric acid reactive substances were measured as an index of lipid peroxidation and oxidative tissue damage. Alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase were parameters for the liver function. Results: The relative liver weight increased significantly with minimal hepatosteatosis in the olive oil treated groups. Lipid peroxidation significantly decreased with near-normal serum levels of the liver function parameters in the olive oil/soybean oil treated groups, and mitotic index and proliferating cell nuclear antigen labeling index reached their maximum level in rats receiving TPN containing any kind of lipid emulsions for 48 h following resection. Conclusions: The use of olive oil/soybean oil lipid emulsions in TPN has important beneficial effects on the liver regeneration, and the antioxidant properties of olive oil originating from its natural components indirectly contribute to the liver regeneration in rats. Copyright © 2003 S. Karger AG, Basel

The effect of folic acid, vitamin B-6 and vitamin B-12 on the homocysteine levels in rabbits fed by methionine-enriched diets

Atherosclerosis is an important cause of cardiovascular morbidity and mortality in recent years. Hyperhomocysteinemia is recognized as an independent risk factor for premature atherosclerosis and venous thrombosis. It is suggested that administration of folic acid, vitamin B-6 and vitamin B-12 may decrease homocysteine levels. In our study, we induced hyperhomocysteinemia in rabbits by giving methionine and studied the effects of folic acid, vitamin B-6 and vitamin B-12 on homocysteine levels. A total of 40 (20 female, 20 male New Zealand rabbits) were divided into four groups, each consisting of 10 rabbits. Methionine (100 mg/kg/day), methionine (100 mg/kg/day) plus vitamin B-6 (30 mg/kg/day), methionine (100 mg/kg/day) plus vitamin B, (80 mg/kg/day) and methionine (100 mg/kg/day) plus folic acid (20 mg/kg/day) were given to the first, second, third and forth groups respectively. These rabbits were followed up for two months. We studied homocysteine levels on the 0, 20th, 40th and 60th days in all groups. In rabbits we induced hyperhomocysteinemia by giving methionine for 2 months. The decreases of homocysteine levels in the forth group were significant with respect to the second and third groups. Folic acid supplementation clearly resulted in a reduction of plasma homocysteine levels, whereas vitamin B-12 was little effective and vitamin B-6 failed to show an effect. We conclude that even folic acid treatment alone may be sufficient for decreasing negative effects of homocysteine. (C) 2002 Tohoku University Medical Press

The effect of allopurinol on focal cerebral ischaemia: an experimental study in rabbits

In this experimental study, the neuroprotective effect of the xanthine oxidase inhibitor allopurinol on focal cerebral ischaemia created by permanent middle cerebral artery occlusion (MCAO) was investigated. Using high performance liquid chromatography (HPLC), we measured hypoxanthine, xanthine, and uric acid (UA) levels in rabbit brains following focal cerebral ischaemia. Rabbits were randomly and blindly assigned into four groups of eight animals each. The control groups received 2% carboxymethylcellulose solution, while 10% allopurinol 150 mg/kg was given to the treatment group 1 h before ischaemia. Each group was subdivided into two groups which were sacrificed 4 h or 24 h after ischaemia, respectively. UA and xanthine values of the rabbits in the control groups were quite high at both times and highest after 24 h, particularly in the centre of the ischaemia. A significant decrease in UA and xanthine values was observed in rabbits that were given allopurinol (P<0.05). According to our results, it was concluded that allopurinol pretreatment protects neural tissue in the early period after arterial occlusion and prevents cerebral injury in the late period, especially in the perifocal area, possibly by preventing the formation of free radicals with xanthine oxidase inhibition