Mehmet Çay

Protective effects of vitamin E on carbon tetrachloride-induced liver damage in rats.

In this study we investigated whether the increase of hepatic vitamin E content by intraperitoneal administration, influences chronic liver damage induced by carbon tetrachloride (CCl4) in rats. Thirty adult male Wistar rats were divided into three groups. The first group was used as a control and the rats in the second group were administered CCl4 in olive oil subcutaneously. Rats in the third group were administered intraperitoneally vitamin E (dl‐α‐tocopherol acetate, 100 mg kg−1). This administration was performed three times per week for five weeks. Liver samples were used for the determination of vitamin E levels, glutathione peroxidase (GSHPx) activities and histological examination.

Blood plasma levels of lipoperoxides, glutathione peroxidase, beta carotene, vitamin A and E in women with habitual abortion.

The plasma levels of lipoperoxides, glutathione peroxidase (GSH‐Px), reduced glutathione (GSH), beta carotene, vitamin A, E, some plasma biochemical and blood haematological parameters were investigated in 40 women with habitual abortion (HA) and controls. The levels of GSH, vitamin A, E and beta carotene were significantly lower in women with HA than in controls. However, the plasma levels of lipid peroxidation, alkaline phosphatase (ALP), glucose and blood haemoglobin were significantly higher in HA than in controls. In addition, plasma levels of GSH‐Px, AST, ALT, total bilirubin, total protein, albumin, sodium, potassium, calcium and number of white blood cells, red blood cells, platelet and values of packet cell volume showed no significant differences between HA and controls. According to the results of this study, we observed that the levels of lipid peroxidation were increased and plasma levels of vitamin A, E and beta carotene were decreased in HA. The decrease of those antioxidants may play a significant role in women with habitual abortion. Copyright

Protective role of intraperitoneally administered vitamin E and selenium on the antioxidative defense mechanisms in rats with diabetes induced by streptozotocin.

The aim of this work was to determine the protective effects of intraperitoneally administered vitamin E and selenium (as Na2SeO3, Se) on the lipid peroxidation as thiobarbituric acid reactive substances (TBARS) and vitamin E levels, glutathione peroxidase (GSH-Px), reduced glutathione (GSH) activities in the plasma, red blood cell (RBC), liver, and muscle of rats with streptozotocin-induced diabetes. Fifty adult male Wistar rats were used and all rats were randomly divided into five groups. The first group was used as a control and the second group as a diabetic control. A placebo was given to first and second groups by injection. The third group was intraperitoneally administered with vitamin E (20 mg over 24 h), the fourth group with Se (0.3 mg over 24 h), and the fifth group with vitamin E and Se combination (COM) (20 mg vitamin E + 0.3 mg Se over 24 h). This administration was done for 25 days and the TBARS, vitamin E, GSH-Px, GSH levels in the plasma, RBC, liver, and muscle samples were determined.The vitamin E level in the plasma and liver was significantly (p < 0.05) higher in the control than in the diabetic control group. Also, the TBARS levels in the RBC, liver, and muscle were significantly (p < 0.05) lower in the control than in the diabetic control group. However, GSH-Px and GSH activities in RBC, liver, and muscle were not statistically different between the control and the diabetic control groups. The vitamin E levels in plasma and liver (p < 0.01 and p < 0.001) and GSH-Px activities (p < 0.01, p < 0.001) in RBC were significantly higher in vitamin E, Se, and COM groups than in both control and diabetic control groups. However, the TBARS levels of RBC, muscle, and liver in vitamin E and Se administered groups were significantly (p < 0.05-p < 0.001, respectively) decreased. These results indicate that intraperitoneally administered vitamin E and Se have significant protective effects on the blood, liver, and muscle against oxidative damage of diabetes.

Protective effects of selenium, vitamin C and vitamin E against oxidative stress of cigarette smoke in rats

Cataractous lenses have been found to have an altered distribution of the intracellular ionic environment; the concentrations of potassium and magnesium being decreased and the concentrations of sodium and calcium increased. These changes arise as a result of changes to lens membrane characteristics causing an increase in lens membrane permeability.

EFFECTS OF INTRAPERITONEALLY-ADMINISTERED VITAMIN E AND SELENIUM ON THE BLOOD BIOCHEMICAL AND HAEMATOLOGICAL PARAMETERS IN RATS

The aim of this work was to determine the role of intraperitoneally‐administered vitamin E and selenium on the biochemical and haematological parameters in the blood of rats. Thirty‐two adult male Wistar rats were used in this study. All rats were randomly divided into four groups. The first group was used as the control. The second group was intraperitoneally administered with vitamin E (±‐α‐tocopheroryl acetate, 10 mg day−1), the third group with Se (Na2SeO3 0·2 mg over a day), and the fourth group with vitamin E and Se (vitamin E 10 mg + Na2SeO3 0·2 mg over a day). This administration was done for 5 weeks. Blood samples were taken from animals at the end of the dosage period and biochemical parameters in serum samples and haematological parameters in total blood were determined. The levels of total cholesterol (p<0·01) and number of white blood cells (p<0·001) in blood were significantly higher in the vitamin E group than in the control group. The levels of ALP, total cholesterol (p<0·01) and number of white blood cells (p<0·01) in blood were significantly higher in the selenium group than in the controls. The levels of glucose (p<0·05), ALP (p<0·01), total cholesterol (p<0·001) and number of white blood cells (p<0·01) were higher in the vitamin E and selenium combined group than in the controls. Other parameters considered within this trial (ALT, LDH, creatinine, albumin, total protein, amylase, creatine kinase, HDL, triglycerides, total lipid, sodium, chloride, uric acids, red blood cell, haemoglobin, packed cell volume, MCV, MCH, MCHC) did not show statistically significant differences between the control and injected groups. The results indicated that blood glucose and total cholesterol levels, ALP activity and white blood cell counts were significantly increased by intraperitoneal administration of vitamin E and selenium in rats. Copyright

The effects of 17β-estradiol and vitamin E treatments on oxidative stress and antioxidant levels in brain cortex of diabetic ovariectomized rats

We investigated the effects of 17beta-estradiol (E 2 ) and vitamin E on lipid peroxidation and antioxidant levels in brain cortex of diabetic ovariectomized (OVX) rats. Forty-two rats were equally divided into seven groups: Control; OVX; OVX+E 2 ; OVX+E 2 +vitamin E; OVX+diabetic; OVX+diabetic+E 2 and OVX+diabetic+E 2 +vitamin E. Then, E 2 (40 microg kg -1 /day) and vitamin E (100 mg kg -1 /day) were given. Glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), vitamin A and beta-carotene in brain were decreased (p<0.05) when compared with control in OVX but MDA in brain and glucose in plasma were elevated (p<0.05). The antioxidant levels in brain (p<0.05) increased although MDA (p<0.05) in brain and glucose (p<0.05, p<0.01) in plasma decreased in OVX after E 2 and E 2 +vitamin E supplementation. The activities of GSH-Px (p<0.001, p<0.01), CAT (p<005, p<0.001) and SOD (p<0.001) and the levels of GSH (p<0.001), vitamin A (p<0.05) and beta-carotene (p<0.001, p<0.05) were lower in the brain of OVX diabetic rats, while MDA in the brain and glucose in the plasma were higher (p<0.001). The antioxidant enzymes (p<0.05, p<0.01), GSH, vitamin A and beta-carotene (p<0.01, p<0.001) in brain increased while MDA in brain and glucose in plasma decreased (p<0.01, p<0.001) in diabetic OVX after treatments. Finally, the E 2 and E 2 +vitamin E supplementation to diabetic OVX and OVX rats may strengthen the antioxidant system by reducing lipid peroxidation.

The study of renin–angiotensin–aldosterone in experimental diabetes mellitus

It is generally accepted that hypertension and other vascular pathologies increase in diabetes mellitus (DM) patients as a result of the renin–angiotensin–aldosterone (RAA) system. In this study, changes in the renin‐angiotensin‐aldosterone (RAA) system level was determined in Streptozotocin (STZ)‐injected rats. A total of 46 female Wistar albino rats (180–220 g body weight) was utilized in these experiments. STZ was given intraperitoneally to induce diabetes in rats. Streptozotocin (60 mg kg−1 body weight) was dissolved in 0·1 m citrate–‐phosphate buffer (pH 4–5). The non‐diabetic rats were injected with sterilized buffer alone to act as a control group. Blood glucose levels were 398±8·2 mg dl−1, 488±11·75 mg dl−1 and 658±29·6 mg dl−1 at days 3, 12 and 30 respectively. The level of plasma renin activity (PRA) was measured as 7·69±1·07 ng ml−1 h−1; 1·82±0·22 ng ml−1 h−1 and 0·67±0·12 ng ml−1 h−1 at days 3, 12 and 30, respectively. These values showed that the PRA levels are decreased with increased time period. Serum angiotensin converting enzyme (ACE, E.C. 3.4.15.1) levels were increased at days 12 and 30 (p<0·05 and p<0·005), whereas serum aldosterone levels were increased at days 3 and 12 (p<0·05). The level of urea and creatinine increased at days 12 and 30 (p<0·05 and p<0·005, respectively) when compared to the control group. The data from these experiments indicate that the PRA level decreased whereas ACE activity level increased in diabetic rats compared with the control. Aldosterone levels increased at the first stage of the experiment, but then decreased by the end of the experiment as a result of changes in renin and ACE levels. Copyright

The Effects of Dietary Selenium and Vitamin E and their Combination on the Fatty Acids of Erythrocytes, Bone Marrow and Spleen Tissue Lipids of Lambs

The object was to determine the influence of dietary vitamin E, selenium and their combination on the fatty acid con‐tent of erythrocytes, bone marrow and spleen lipids of Akkaraman lambs. After supplementation for 15 days, the amount of all fatty acids was slightly higher (p < 0·05) in the vitamin E as compared to the control group, whereas the amount of longer fatty acids was significantly higher (p < 0·01, p < 0·001) in the selenium and combination groups. On the thirtieth day, the amount of all fatty acids was slightly high (p < 0·5) in all the supplemented groups in comparison with the control group. In the bone marrow lipids, the amount of longer fatty acids was decreased (p < 0·05, p < 0·01, p < 0·001) in the vitamin E and combination groups as compared to the control. Although the amount of some fatty acids was high (p < 0·05, p < 0·01) in the selenium group compared to the control, linoleic (18:2), linolenic (18:3) and the polyunsaturated fatty acids (PUFA) were lower (p < 0·05, p < 0·001). In the spleen lipids, the amount of longer fatty acids was slightly decreased (p < 0·05) in the vitamin E group as compared with the control; however the amount of longer fatty acids was significantly higher (p < 0·05, p < 0·01) in the selenium and combination groups in comparison to the control group. Thus dietary supplementation with selenium was more effective than dietary vitamin E supplementation in altering the fatty acid content of the erythrocyte, bone marrow and spleen lipids.

Effectiveness of cinnamon (Cinnamomum zeylanicum) bark oil in the prevention of carbon tetrachloride-induced damages on the male reproductive system

In this study, it was aimed to investigate the likelihood of detrimental effects of carbon tetrachloride (CCl4) on male reproductive system through oxidative stress mechanism and also protective effects of cinnamon bark oil (CBO). For this purpose, 28 healthy male Wistar rats were divided into four groups, seven rats in each. Group 1 received only olive oil daily; group 2 was treated with 100 mg kg−1 CBO daily; group 3 was treated with only 0.25 ml kg−1 CCl4 weekly; and group 4 received weekly CCl4 + daily CBO. All administrations were made by intragastric catheter and maintained for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular oxidative stress markers and testicular apoptosis were examined. CCl4 administration caused significant decreases in body and reproductive organ weights, testicular catalase (CAT) activity, sperm motility and concentration, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and apoptotic index along with some histopathological damages compared with the control group. However, significant improvements were observed in absolute weights of testis and epididymis, all sperm quality parameters, LPO level, apoptotic index and testicular histopathological structure following the administration of CCl4 together with CBO when compared to group given CCl4 only. The findings of this study clearly suggest that CBO has protective effect against damages in male reproductive organs and cells induced by CCl4.

Protective role of intraperitoneally administrated vitamin E and selenium on the levels of total lipid, total cholesterol, and fatty acid composition of muscle and liver tissues in rats.

The aim of this work was to determine the protective effects of intraperitoneally administrated vitamin E and Se on total lipid, total cholesterol, and fatty acid composition of rat liver and muscle tissues. Total lipid content of muscle tissue in Se and combination groups decreased as compared to the control group. However, the level of total lipid in the liver tissues was seen to decrease only in the combination group (P < 0.05). While the amount of total cholesterol in liver tissue was lower (P < 0.05) in the vitamin E and combination groups, the amount of total cholesterol in muscle tissue decreased (P < 0.05) in the combination group.